The 100 most-cited articles in The FASEB Journal, 2021

Mitochondria are highly dynamic, maternally inherited cytoplasmic organelles, which fulfill cellular energy demand through the oxidative phosphorylation system. Besides, they play an active role in calcium and damage-associated molecular patterns signaling, amino acid, and lipid metabolism, and apoptosis. Thus, the maintenance of mitochondrial integrity and homeostasis is extremely critical, which is achieved through continual fusion and fission. Mitochondrial fusion allows the transfer of gene products between mitochondria for optimal functioning, especially under metabolic and environmental stress. On the other hand, fission is crucial for mitochondrial division and quality control. The imbalance between these two processes is associated with various ailments such as cancer, neurodegenerative and cardiovascular diseases. This review discusses the molecular mechanisms that control mitochondrial fusion and fission and how the disruption of mitochondrial dynamics manifests into various disease conditions.

Exosomes are a novel class of intercellular signal modulators that contain a wide range of molecules and deliver information between cells and tissues. MicroRNAs (miRNAs), a type of regulatory non-coding RNA, are often incorporated into exosomes as signaling molecules. In this review, we discuss the expression of exosomal miRNAs from diverse origins such as tumor cells, solid tumor tissue, and biological fluids in various cancers (lung, breast, colorectal, liver, stomach, and pancreatic). We address the biological functions of exosome-derived miRNAs in processes such as tumor-cell proliferation, angiogenesis, metastasis, and chemoresistance in the tumor microenvironment. In particular, we discuss three oncogenic miRNAs, miR-21, miR-141, and miR-451, which occur within exosomes, in terms of gene regulation and intercellular communication. We consider therapeutic miRNA-based nanoparticles, which are widely expressed in tumors and show promise in drug therapy. The review assesses the wide-ranging evidence for using exosomal miRNAs as tumor markers in molecular diagnosis. Further, we…

ABSTRACT BACKGROUND Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) is the infectious agent responsible for Coronavirus disease 2019 (COVID-19). While SARS-CoV-2 infections are often benign, there are also severe COVID-19 cases, characterized by severe bilobar pneumonia that can decompensate to an acute respiratory distress syndrome, notably characterized by increased inflammation and a cytokine storm. While there is no cure against severe COVID-19 cases, some treatments significantly decrease the severity of the disease, notably aspirin and dexamethasone, which both directly or indirectly target the biosynthesis (and effects) of numerous bioactive lipids. OBJECTIVE Our working hypothesis was that severe COVID-19 cases necessitating mechanical ventilation were characterized by increased bioactive lipid levels modulating lung inflammation. We thus quantitated several lung bioactive lipids using liquid chromatography combined to tandem mass spectrometry. RESULTS We performed an exhaustive assessment of the lipid content of bronchoalveolar lavages from 25 healthy controls…

Abstract Copper (Cu) is an essential micronutrient required for the activity of redox‐active enzymes involved in critical metabolic reactions, signaling pathways, and biological functions. Transporters and chaperones control Cu ion levels and bioavailability to ensure proper subcellular and systemic Cu distribution. Intensive research has focused on understanding how mammalian cells maintain Cu homeostasis, and how molecular signals coordinate Cu acquisition and storage within organs. In humans, mutations of genes that regulate Cu homeostasis or facilitate interactions with Cu ions lead to numerous pathologic conditions. Malfunctions of the Cu + ‐transporting ATPases ATP7A and ATP7B cause Menkes disease and Wilson disease, respectively. Additionally, defects in the mitochondrial and cellular distributions and homeostasis of Cu lead to severe neurodegenerative conditions, mitochondrial myopathies, and metabolic diseases. Cu has a dual nature in carcinogenesis as a promotor of tumor growth and an inducer of redox stress in cancer cells. Cu also plays role in cancer treatment as a…

Endogenous tryptophan metabolism pathways lead to the production of serotonin (5-hydroxytryptamine; 5-HT), kynurenine, and several downstream metabolites which are involved in a multitude of immunological functions in both health and disease states. Ingested tryptophan is largely shunted to the kynurenine pathway (95%) while only minor portions (1%-2%) are sequestered for 5-HT production. Though often associated with the functioning of the central nervous system, significant production of 5-HT, kynurenine and their downstream metabolites takes place within the gut. Accumulating evidence suggests that these metabolites have essential roles in regulating immune cell function, intestinal inflammation, as well as in altering the production and suppression of inflammatory cytokines. In addition, both 5-HT and kynurenine have a considerable influence on gut microbiota suggesting that these metabolites impact host physiology both directly and indirectly via compositional changes. It is also now evident that complex interactions exist between the two pathways to maintain gut homeostasis.…

Pyroptosis and intrinsic apoptosis are two forms of regulated cell death driven by active caspases where plasma membrane permeabilization is induced by gasdermin pores. Caspase-1 induces gasdermin D pore formation during pyroptosis, whereas caspase-3 promotes gasdermin E pore formation during apoptosis. These two types of cell death are accompanied by mitochondrial outer membrane permeabilization due to BAK/BAX pore formation in the external membrane of mitochondria, and to some extent, this complex also affects the inner mitochondrial membrane facilitating mitochondrial DNA relocalization from the matrix to the cytosol. However, the detailed mechanism responsible for this process has not been investigated. Herein, we reported that gasdermin processing is required to induce mitochondrial DNA release from cells during pyroptosis and apoptosis. Gasdermin targeted at the plasma membrane promotes a fast mitochondrial collapse along with the initial accumulation of mitochondrial DNA in the cytosol and then facilitates the DNA's release from the cell when the plasma membrane ruptures.…

Satellite cells support adult skeletal muscle fiber adaptations to loading in numerous ways. The fusion of satellite cells, driven by cell-autonomous and/or extrinsic factors, contributes new myonuclei to muscle fibers, associates with load-induced hypertrophy, and may support focal membrane damage repair and long-term myonuclear transcriptional output. Recent studies have also revealed that satellite cells communicate within their niche to mediate muscle remodeling in response to resistance exercise, regulating the activity of numerous cell types through various mechanisms such as secretory signaling and cell-cell contact. Muscular adaptation to resistance and endurance activity can be initiated and sustained for a period of time in the absence of satellite cells, but satellite cell participation is ultimately required to achieve full adaptive potential, be it growth, function, or proprioceptive coordination. While significant progress has been made in understanding the roles of satellite cells in adult muscle over the last few decades, many conclusions have been extrapolated from…

Osteoporosis is the most common metabolic skeletal disease. It is characterized by the deterioration of the skeletal microarchitecture and bone loss, leading to ostealgia, and even bone fractures. Accumulating evidence has indicated that there is an inextricable relationship between the gut microbiota (GM) and bone homeostasis involving host-microbiota crosstalk. Any perturbation of the GM can play an initiating and reinforcing role in disrupting the bone remodeling balance during the development of osteoporosis. Although the GM is known to influence bone metabolism, the mechanisms associated with these effects remain unclear. Herein, we review the current knowledge of how the GM affects bone metabolism in health and disease, summarize the correlation between pathogen-associated molecular patterns of GM structural components and bone metabolism, and discuss the potential mechanisms underlying how GM metabolites regulate bone turnover. Deciphering the complicated relationship between the GM and bone health will provide new insights into the prevention and treatment of osteoporosis.

How regular physical activity is able to improve health remains poorly understood. The release of factors from skeletal muscle following exercise has been proposed as a possible mechanism mediating such systemic benefits. We describe a mechanism wherein skeletal muscle, in response to a hypertrophic stimulus induced by mechanical overload (MOV), released extracellular vesicles (EVs) containing muscle-specific miR-1 that were preferentially taken up by epidydimal white adipose tissue (eWAT). In eWAT, miR-1 promoted adrenergic signaling and lipolysis by targeting Tfap2α, a known repressor of Adrβ3 expression. Inhibiting EV release prevented the MOV-induced increase in eWAT miR-1 abundance and expression of lipolytic genes. Resistance exercise decreased skeletal muscle miR-1 expression with a concomitant increase in plasma EV miR-1 abundance, suggesting a similar mechanism may be operative in humans. Altogether, these findings demonstrate that skeletal muscle promotes metabolic adaptations in adipose tissue in response to MOV via EV-mediated delivery of miR-1.

Abstract The electron transport chain (ETC) couples oxidative phosphorylation (OXPHOS) with ATP synthase to drive the generation of ATP. In immune cells, research surrounding the ETC has drifted away from bioenergetics since the discovery of cytochrome c (Cyt c ) release as a signal for programmed cell death. Complex I has been shown to generate reactive oxygen species (ROS), with key roles identified in inflammatory macrophages and T helper 17 cells (T H 17) cells. Complex II is the site of reverse electron transport (RET) in inflammatory macrophages and is also responsible for regulating fumarate levels linking to epigenetic changes. Complex III also produces ROS which activate hypoxia‐inducible factor 1‐alpha (HIF‐1α) and can participate in regulatory T cell (T reg ) function. Complex IV is required for T cell activation and differentiation and the proper development of T reg subsets. Complex V is required for T H 17 differentiation and can be expressed on the surface of tumor cells where it is recognized by anti‐tumor T and NK cells. In this review, we summarize these findings…

Abstract T cell factor‐1 (TCF‐1) (encoded by the TCF7 gene) is a transcription factor that plays important role during the T cell development and differentiation for T cell to exercise its functions including producing memory T cells. Not only TCF‐1 can modulate the T cell development but also exerts various effects on the differentiation and function of mature CD8 + T cells. In addition, it drives the production and maintenance of the immune response of CD8 + T cells after PD‐1 checkpoint blockade therapy. TCF‐1 can serve as a potential target of immunotherapy and may provide promising novel treatment strategies for patients with cancer and infections. Moreover, TCF‐1 is a potential biomarker of CD8 + T cell functionality to predict the efficacy of immunotherapy in fighting against cancer and infections. Herein, we summarize the role of TCF‐1 in T cell development and its applications in the treatment of cancer and infectious diseases.

The COVID-19 pandemic has unfolded to be the most challenging global health crisis in a century. In 11 months since its first emergence, according to WHO, the causative infectious agent SARS-CoV-2 has infected more than 100 million people and claimed more than 2.15 million lives worldwide. Moreover, the world has raced to understand the virus and natural immunity and to develop vaccines. Thus, within a short 11 months a number of highly promising COVID-19 vaccines were developed at an unprecedented speed and are now being deployed via emergency use authorization for immunization. Although a considerable number of review contributions are being published, all of them attempt to capture only a specific aspect of COVID-19 or its therapeutic approaches based on ever-expanding information. Here, we provide a comprehensive overview to conceptually thread together the latest information on global epidemiology and mitigation strategies, clinical features, viral pathogenesis and immune responses, and the current state of vaccine development.

Histone H3K4me1 and H3K27ac are enhancer-specific modifications and are required for enhancers to activate transcription of target genes. However, the reciprocal effects of these histone modifications on each other and their roles in enhancers are not clear. Here to comparatively analyze the role of these modifications, we inhibited H3K4me1 and H3K27ac by deleting the SET domains of histone methyltransferases MLL3 and MLL4 and the HAT domain of histone acetyltransferase p300, respectively, in erythroid K562 cells. The loss of H3K4me1 reduced H3K27ac at the β-globin enhancer LCR HSs, but H3K27ac reduction did not affect H3K4me1. This unequal relationship between two modifications was revealed in putative enhancers by genome-wide analysis using ChIP-seq. Histone H3 eviction at putative enhancers was weakened by the loss of H3K4me1 but not by the loss of H3K27ac. Chromatin remodeling complexes were recruited into the β-globin LCR HSs in a H3K4me1-dependent manner. In contrast, H3K27ac was required for enhancer RNA (eRNA) transcription, and H3K4me1 was not enough for it. Forced…

Despite the importance of germ cell (GC) differentiation for sexual reproduction, the gene networks underlying their fate remain unclear. Here, we comprehensively characterize the gene expression dynamics during sex determination based on single-cell RNA sequencing of 14 914 XX and XY mouse GCs between embryonic days (E) 9.0 and 16.5. We found that XX and XY GCs diverge transcriptionally as early as E11.5 with upregulation of genes downstream of the bone morphogenic protein (BMP) and nodal/Activin pathways in XY and XX GCs, respectively. We also identified a sex-specific upregulation of genes associated with negative regulation of mRNA processing and an increase in intron retention consistent with a reduction in mRNA splicing in XY testicular GCs by E13.5. Using computational gene regulation network inference analysis, we identified sex-specific, sequential waves of putative key regulator genes during GC differentiation and revealed that the meiotic genes are regulated by positive and negative master modules acting in an antagonistic fashion. Finally, we found that rare adrenal GCs…

Historically the chemokine receptor CXCR4 and its canonical ligand CXCL12 are associated with the bone marrow niche and hematopoiesis. However, CXCL12 exhibits broad tissue expression including brain, thymus, heart, lung, liver, kidney, spleen, and bone marrow. CXCR4 can be considered as a node which is integrating and transducing inputs from a range of ligand-receptor interactions into a responsive and divergent network of intracellular signaling pathways that impact multiple cellular processes such as proliferation, migration, and stress resistance. Dysregulation of the CXCR4/CXCL12 axis and consequent fundamental cellular processes, are associated with a panoply of disease. This review frames the polyfunctionality of the receptor at a molecular, physiological, and pathophysiological levels. Transitioning our perspective of this axis from a single gene/protein:single function model to a polyfunctional signaling cascade highlights the potential for finer therapeutic intervention and cautions against a reductionist approach.

Abstract Hepatic fibrosis is a wound healing response that results in excessive extracellular matrix (ECM) accumulation in response to chronic hepatic injury. Signal transducer and activator of transcription 3 (STAT3) is an important transcription factor associated with the pathogenesis of liver fibrosis. Though a promising potential therapeutic target, there are no specific drug candidates for STAT3. Exosomes are extracellular vesicles generated by all cell types with a capacity to efficiently enter cells across different biological barriers. Here, we utilize exosomes as delivery conduit to specifically target STAT3 in liver fibrosis. Exosomes derived from clinical grade fibroblast‐like mesenchymal stem cells (MSCs) were engineered to carry siRNA or antisense oligonucleotide (ASO) targeting STAT3 (iExo siRNA‐STAT3 or iExo mASO‐STAT3 ). Compared to scrambled siRNA control, siRNA‐STAT3, or ASO‐STAT3, iExo siRNA‐STAT3 or iExo mASO‐STAT3 showed enhanced STAT3 targeting efficiency. iExo siRNA‐STAT3 or iExo mASO‐STAT3 treatments suppressed STAT3 levels and ECM deposition in established…

Large clinical trials and real-world studies have demonstrated that the beneficial effects of sodium-glucose co-transporter 2 (SGLT2) inhibitors on renal outcomes regardless of the presence of diabetes. However, the mechanism remains obscure. Here, we analyze the anti-fibrotic and anti-inflammatory effects of dapagliflozin, a SGLT2 inhibitor, on renal alternations using the ischemia/reperfusion-induced fibrosis model. Transcriptome and metabolome analysis showed that the accumulation of tricarboxylic acid (TCA) cycle metabolites and upregulation of inflammation in fibrosis renal cortical tissue were mitigated by dapagliflozin treatment. Moreover, dapagliflozin markedly relieved the activation of mammalian target of rapamycin and hypoxia inducible factor-1α signaling and restored tubular cell-preferred fatty acid oxidation. Notably, NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome activation was strikingly blocked by dapagliflozin. We further demonstrated that the immunomodulatory metabolite itaconate derived from the TCA cycle was significantly boosted as a…

Exosomes are extracellular vesicles that are released from most cell types encapsulating specific molecular cargo. Exosomes serve as mediators of cell-to-cell and tissue-to-tissue communications under normal and pathological conditions. It has been shown that exosomes carrying muscle-specific miRNAs, myomiRs, are secreted from skeletal muscle cells in vitro and are elevated in the blood of muscle disease patients. The aim of this study was to investigate the secretion of exosomes encapsulating the four myomiRs from skeletal muscle tissues and to assess their role in inter-tissue communication between neighboring skeletal muscles in vivo. We demonstrate, for the first time, that isolated, intact skeletal muscle tissues secrete exosomes encapsulating the four myomiRs, miR-1, miR-133a, miR-133b, and miR-206. Notably, we show that the sorting of the four myomiRs within exosomes varies between skeletal muscles of different muscle fiber-type composition. miR-133a and miR-133b downregulation in TA muscles caused a reduction of their levels in neighboring skeletal muscles and in serum…

Abstract The endometrium is a dynamic tissue that exhibits remarkable resilience to repeated episodes of differentiation, breakdown, regeneration and remodelling. Endometrial physiology relies on a complex interplay between the stromal and epithelial compartments with the former containing a mixture of fibroblasts, vascular and immune cells. There is evidence for rare populations of putative mesenchymal progenitor cells located in the perivascular niche of human endometrium, but the existence of an equivalent cell population in mouse is unclear. In the current study we used the Pdgfrb -BAC-eGFP transgenic reporter mouse in combination with bulk and single cell RNA sequencing (scRNAseq) to redefine the endometrial mesenchyme. Contrary to previous reports we show that CD146 is expressed in both PDGFRβ+ perivascular cells as well as CD31+ endothelial cells. Bulk RNAseq revealed cells in the perivascular niche which express high levels of Pdgfrb as well as genes previously identified in pericytes and/or vascular smooth muscle cells ( Acta2, Myh11, Olfr78, Cspg4, Rgs4, Rgs5, Kcnj8, Abcc9…

The variations and dynamics of essential and toxic metal(loid)s in patients with COVID-19 may associate with the progression and fatal outcome of the disease, which still remains to investigate. In the present study, a retrospective analysis was performed in a cohort of 306 confirmed COVID-19 patients admitted to Tongji hospital (Wuhan, China) from February 10 to March 15, 2020. Whole blood levels of essential and/or toxic metal(loid)s were analyzed, including magnesium, calcium, chromium, manganese, iron, copper, zinc, arsenic, cadmium, mercury, thallium, and lead according to the disease severity and outcome. Compared to the non-severe COVID-19 patients, severe cases showed significant higher levels of whole blood calcium, chromium, and copper, but lower levels of magnesium, manganese, iron, zinc, arsenic, thallium, and lead. These differences were further found consistently across the clinical course since the disease onset by longitudinal analysis. Among the severe patients, chromium and cadmium were higher in the deceased group compared to the recovered group, while arsenic was…

Mitochondria share attributes of vesicular transport with their bacterial ancestors given their ability to form mitochondrial-derived vesicles (MDVs). MDVs are involved in mitochondrial quality control and their formation is enhanced with stress and may, therefore, play a potential role in mitochondrial-cellular communication. However, MDV proteomic cargo has remained mostly undefined. In this study, we strategically used an in vitro MDV budding/reconstitution assay on cardiac mitochondria, followed by graded oxidative stress, to identify and characterize the MDV proteome. Our results confirmed previously identified cardiac MDV markers, while also revealing a complete map of the MDV proteome, paving the way to a better understanding of the role of MDVs. The oxidative stress vulnerability of proteins directed the cargo loading of MDVs, which was enhanced by antimycin A (Ant-A). Among OXPHOS complexes, complexes III and V were found to be Ant-A-sensitive. Proteins from metabolic pathways such as the TCA cycle and fatty acid metabolism, along with Fe-S cluster, antioxidant response…

Impaired glucose homeostasis in obesity is mitigated by enhancing the glucoregulatory actions of glucagon-like peptide 1 (GLP-1), and thus, strategies that improve GLP-1 sensitivity and secretion have therapeutic potential for the treatment of type 2 diabetes. This study shows that Holdemanella biformis, isolated from the feces of a metabolically healthy volunteer, ameliorates hyperglycemia, improves oral glucose tolerance and restores gluconeogenesis and insulin signaling in the liver of obese mice. These effects were associated with the ability of H. biformis to restore GLP-1 levels, enhancing GLP-1 neural signaling in the proximal and distal small intestine and GLP-1 sensitivity of vagal sensory neurons, and to modify the cecal abundance of unsaturated fatty acids and the bacterial species associated with metabolic health. Our findings overall suggest the potential use of H biformis in the management of type 2 diabetes in obesity to optimize the sensitivity and function of the GLP-1 system, through direct and indirect mechanisms.

Circulating neutrophil extracellular traps (NETs) resistant to t-PA have not been studied completely although NETs in thrombi may contribute to tissue plasminogen activator (t-PA) resistance. This research intended to elucidate whether circulating NETs are associated with t-PA resistance and the underlying mechanism. The levels of NETs were detected in the circulating neutrophils, ischemic brain tissue of acute ischemic stroke (AIS) patients, and transient middle cerebral artery occlusion (tMCAO) models. NET formation in blood, thrombi, and ischemic brain tissue of mice were analyzed by immunofluorescence. Exposed phosphatidylserine (PS) was assessed using flow cytometry and confocal microscopy. Procoagulant activity (PCA) was evaluated using fibrin formation assays, thrombin, and purified coagulation complex. The plasma levels of NETs in AIS patients were significantly higher than those in healthy individuals. After thrombolysis, a significant increase was noted in NET markers in no-improvement patients, while the changes in improvement patients were not significant. Importantly,…

Decidualizing endometrial stromal cells (EnSC) critically determine the maternal response to an implanting conceptus, triggering either menstruation-like disposal of low-fitness embryos or creating an environment that promotes further development. However, the mechanism that couples maternal recognition of low-quality embryos to tissue breakdown remains poorly understood. Recently, we demonstrated that successful transition of the cycling endometrium to a pregnancy state requires selective elimination of pro-inflammatory senescent decidual cells by activated uterine natural killer (uNK) cells. Here we report that uNK cells express CD44, the canonical hyaluronan (HA) receptor, and demonstrate that high molecular weight HA (HMWHA) inhibits uNK cell-mediated killing of senescent decidual cells. In contrast, low molecular weight HA (LMWHA) did not attenuate uNK cell activity in co-culture experiments. Killing of senescent decidual cells by uNK cells was also inhibited upon exposure to medium conditioned by IVF embryos that failed to implant, but not successful embryos. Embryo-mediated…

Abstract Nicotinamide adenine dinucleotide (NAD + ) homeostasis is constantly compromised due to degradation by NAD + ‐dependent enzymes. NAD + replenishment by supplementation with the NAD + precursors nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR) can alleviate this imbalance. However, NMN and NR are limited by their mild effect on the cellular NAD + pool and the need of high doses. Here, we report a synthesis method of a reduced form of NMN (NMNH), and identify this molecule as a new NAD + precursor for the first time. We show that NMNH increases NAD + levels to a much higher extent and faster than NMN or NR, and that it is metabolized through a different, NRK and NAMPT‐independent, pathway. We also demonstrate that NMNH reduces damage and accelerates repair in renal tubular epithelial cells upon hypoxia/reoxygenation injury. Finally, we find that NMNH administration in mice causes a rapid and sustained NAD + surge in whole blood, which is accompanied by increased NAD + levels in liver, kidney, muscle, brain, brown adipose tissue, and heart, but not in white…

Abstract Peroxisome proliferator‐activated receptor gamma (PPARγ) is a master regulator of adipogenesis and lipogenesis. To understand its roles in fiber formation and fat deposition in skeletal muscle, we successfully generated muscle‐specific overexpression of PPARγ in two pig models by random insertion and CRISPR/Cas9 transgenic cloning procedures. The content of intramuscular fat was significantly increased in PPARγ pigs while had no changes on lean meat ratio. PPARγ could promote adipocyte differentiation by activating adipocyte differentiating regulators such as FABP4 and CCAAT/enhancer‐binding protein (C/EBP), along with enhanced expression of LPL, FABP4, and PLIN1 to proceed fat deposition. Proteomics analyses demonstrated that oxidative metabolism of fatty acids and respiratory chain were activated in PPARγ pigs, thus, gathered more Ca 2+ in PPARγ pigs. Raising of Ca 2+ could result in increased phosphorylation of CAMKII and p38 MAPK in PPARγ pigs, which can stimulate MEF2 and PGC1α to affect fiber type and oxidative capacity. These results support that skeletal…

Cognitive dysfunction often occurs in diabetes mellitus patients. This study aimed to investigate the efficacy of melatonin (MLT) in improving diabetes-associated cognitive decline and the underlying mechanism involved. Type 2 diabetic mice and palmitic acid (PA)-stimulated BV-2 cells were treated by MLT, and the potential mechanisms among MLT, cognition, and autophagy were explored. The results showed that type 2 diabetic mice showed obvious learning and memory impairments in the Morris water maze test compared with normal controls, which could be ameliorated by MLT treatment. Meanwhile, MLT administration significantly improved neuroinflammation and regulated microglial apoptosis. Furthermore, autophagy inhibitor 3-methyladenine (3-MA) increased the microglial inflammation and apoptosis, indicating that the treatment effect of MLT was mediated by autophagy. Lastly, MLT treatment significantly decreased the levels of toll-like receptors 4 (TLR4), phosphorylated-protein kinase B (Akt), and phosphorylated-mechanistic target of rapamycin (mTOR), indicating that blocking TLR4/Akt/mTOR…

Host-pathogen interactions play an important role in defining the outcome of a disease. Recent studies have shown that the bacterial quorum sensing molecules (QSM) can interact with host cell membrane proteins, mainly G protein-coupled receptors (GPCRs), and induce innate immune responses. However, few studies have examined QSM-GPCR interactions and their influence on oral innate immune responses. In this study, we examined the role of bitter taste receptor T2R14 in sensing competence stimulating peptides (CSPs) secreted by cariogenic bacterium Streptococcus mutans and in mediating innate immune responses in gingival epithelial cells (GECs). Transcriptomic and western blot analyses identify T2R14 to be highly expressed in GECs. Our data show that only CSP-1 from S. mutans induces robust intracellular calcium mobilization compared to CSP-2 and CSP-3. By using CRISPR-Cas9, we demonstrate that CSP-1 induced calcium signaling and secretion of cytokines CXCL-8/IL-8, TNF-α, and IL-6 is mediated through T2R14 in GECs. Interestingly, the NF-kB signaling activated by CSP-1 in GECs was…

Abstract Tim‐3 is a negative immunoregulator in anti‐tumor response, but its mechanism in chronic lymphocytic leukemia (CLL) is not yet clear. The aim of this study was to understand the role of Galectin‐9/Tim‐3 signaling pathway in the regulation of CD4 + T cell subsets in CLL patients. Flow cytometry results showed that the number of Treg cells obviously increased, and there was a significant Treg/Th17 imbalance in CLL patients. In addition, Tim‐3 overexpressed on the surface of Th1 and Treg cells in CLL patients. The levels of Galectin‐9 and IL‐10 were significantly elevated in patients of CLL, especially in stages of Binet B, and C. However, IFN‐γ decreased. Moreover, Galectin‐9 in CLL patients was positively correlated with the number of Tim‐3 + Treg cells and the level of IL‐10. Interestingly, when the Tim‐3/Galectin‐9 pathway was blocked in vitro, the level of IL‐10 in the culture supernatant of CD4 + T was significantly reduced, while the levels of IFN‐γ and TNF‐α were increased. After co‐culture with activated Th1 cells, the apoptosis of CLL cells was significantly…

Tissues undergo a process of degeneration as the body ages. Mesenchymal stem cells (MSCs) have been found to have major potential in delaying the aging process in tissues and organs. However, the mechanism underlying the anti-aging effects of MSC is not clear which limits clinical applications. In this study, we used adipose-derived mesenchymal stem cells (ADSCs) to perform anti-aging treatments on senescent cells and progeroid animal models. Following intervention with ADSCs, replicative senescence was delayed and metabolic homeostasis was transformed from catabolism to anabolism. Metabolomic tests were used to analyze different metabolites. We found that ADSCs acted to accelerate mitophagy which eliminated intracellular ROS and improved the quality of mitochondria. These processes acted to regulate the cellular metabolic homeostasis and ultimately delayed the process of aging. Allogeneic stem cell therapy in a Progeria animal model (DNA polymerase gamma (POLG) knockin, mitochondrial dysfunction) also showed that ADSC therapy can improve alopecia and kyphosis by promoting…

As fish constitute the first evolutionary group with primordial T cells, they are of importance for understanding the origin and evolution of adaptive immunity. Yet, the knowledge about how ancestral T cells function remains limited. Therefore, the teleost model Nile tilapia (Oreochromis niloticus) was used in this study to investigate the regulatory mechanisms of T-cell immunity in fish. We identified an evolutionarily conserved canonical NF-κB signaling pathway in Nile tilapia, which participates in primary adaptive immune response during Streptococcus agalactiae infection. Blockade of NF-κB activity severely impairs T-cell activation and expansion, rendering the animals more vulnerable to pathogen attack. Meanwhile, NF-κB signaling is indispensable for fish T cells to produce IL-17A during the antibacterial immune response. Moreover, IL-17A binds its receptor IL-17RA, initiates the ACT1-TRAF6-TAK1 axis, and triggers NF-κB-dependent T-cell activation, thus forming a positive feedback loop of T-cell immunity in Nile tilapia. Furthermore, IL-17A seems to promote innate immunity by…

This study aims to elucidate the relationships between gut microbiota, bile acid metabolism, and psychological comorbidity in Crohn's disease (CD). We profiled the fecal microbiota composition and quantified the bile acid pool of 39 CD patients and 14 healthy controls using 16S rRNA gene sequencing and liquid chromatography-tandem mass spectrometry, respectively. Significant reductions in the secondary bile acids, LCA and DCA, were found in both the feces and serum samples of CD patients, while the concentration of 7-DHCA was particularly higher in the serum of CD patients with psychological disorders. The fecal levels of HDCA and 12-DHCA of the CD patients were inversely correlated with their Self-Rated Depression Scale (SDS) scores, whereas the serum level of 7-DHCA was positively correlated with the SDS scores. In addition, the fecal levels of TDCA, TLCA, and TβMCA showed a positive correlation with the Self-Rated Anxiety Scale (SAS) scores. The fecal microbiota biodiversity was particularly declined in CD patients with psychological disorders. An enrichment of Ruminococcus…

The novel coronavirus disease, COVID-19, has grown into a global pandemic and a major public health threat since its breakout in December 2019. To date, no specific therapeutic drug or vaccine for treating COVID-19 and SARS has been FDA approved. Previous studies suggest that berberine, an isoquinoline alkaloid, has shown various biological activities that may help against COVID-19 and SARS, including antiviral, anti-allergy and inflammation, hepatoprotection against drug- and infection-induced liver injury, as well as reducing oxidative stress. In particular, berberine has a wide range of antiviral activities such as anti-influenza, anti-hepatitis C, anti-cytomegalovirus, and anti-alphavirus. As an ingredient recommended in guidelines issued by the China National Health Commission for COVID-19 to be combined with other therapy, berberine is a promising orally administered therapeutic candidate against SARS-CoV and SARS-CoV-2. The current study comprehensively evaluates the potential therapeutic mechanisms of berberine in preventing and treating COVID-19 and SARS using computational…

An excessive, non-resolving inflammatory response underlies severe COVID-19 that may have fatal outcomes. Therefore, the investigation of endogenous pathways leading to resolution of inflammation is of interest to uncover strategies for mitigating inflammation in people with SARS-CoV-2 infection. This becomes particularly urgent in individuals with preexisting pathologies characterized by chronic respiratory inflammation and prone to bacterial infection, such as cystic fibrosis (CF). Here, we analyzed the immune responses to SARS-CoV-2 virion spike 1 glycoprotein (S1) of macrophages (MΦ) from volunteers with and without CF and tested the efficacy of resolvins (Rv) D1 and D2 in regulating the inflammatory and antimicrobial functions of MΦ exposed to S1. S1 significantly increased chemokine release, including interleukin (IL)-8, in CF and non-CF MΦ, while it enhanced IL-6 and tumor necrosis factor (TNF)-α in non-CF MΦ, but not in CF cells. S1 also triggered the biosynthesis of RvD1 and modulated microRNAs miR-16, miR-29a, and miR-103, known to control the inflammatory responses. RvD1…

In the midst of the current coronavirus pandemic, the United States continues to struggle with an ongoing opioid epidemic, initially fueled by widespread prescribing of opioid medications during the 1990s. The primary reason for prescribing opioids is to treat pain. Women have more acute and chronic pain and have been prescribed these drugs in significantly greater numbers than men. Comparison of women and men with chronic pain also shows that women receive the majority of prescription opioids, and the use of these prescribed medications became the major pathway to misuse and addiction for women. Yet, recognition of the extent of women's exposure to opioids and the attendant consequences has been limited. Attempts to stem the overall tide of the epidemic focused on reducing the availability of prescription opioids. However, as these medications became more difficult to obtain and treatment opportunities were limited, many turned to other synthetic opioids, such as heroin and fentanyl. Thus, the public health crisis of opioid addiction has endured. This paper highlights the…

Mitochondria are intimately connected to cell fate and function. Here, we review how these intracellular organelles participate in the induction and maintenance of the senescent state. In particular, we discuss how alterations in mitochondrial metabolism, quality control and dynamics are all involved in various aspects of cellular senescence. Together, these observations suggest that mitochondria are active participants and are mechanistically linked to the unique biology of senescence. We further describe how these insights can be potentially exploited for therapeutic benefit.

Ovarian infertility and subfertility presenting with premature ovarian insufficiency (POI) and diminished ovarian reserve are major issues facing the developed world due to the trend of delaying childbirth. Ovarian senescence and POI represent a continuum of physiological/pathophysiological changes in ovarian follicle functions. Based on advances in whole exome sequencing, evaluation of gene copy variants, together with family-based and genome-wide association studies, we discussed genes responsible for POI and ovarian senescence. We used a gene-centric approach to sort out literature deposited in the Ovarian Kaleidoscope database (http://okdb.appliedbioinfo.net) by sub-categorizing candidate genes as ligand-receptor signaling, meiosis and DNA repair, transcriptional factors, RNA metabolism, enzymes, and others. We discussed individual gene mutations found in POI patients and verification of gene functions in gene-deleted model organisms. Decreased expression of some of the POI genes could be responsible for ovarian senescence, especially those essential for DNA repair, meiosis and…

Melatonin pleiotropically regulates physiological events and has a putative regulatory role in the circadian clock desynchrony-mediated Non-alcoholic fatty liver disease (NAFLD). In this study, we investigated perturbations in the hepatic circadian clock gene, and Nrf2-HO-1 oscillations in conditions of high-fat high fructose (HFHF) diet and/or jet lag (JL)-mediated NAFLD. Melatonin treatment (100 µM) to HepG2 cells led to an improvement in oscillatory pattern of clock genes (Clock, Bmal1, and Per) in oleic acid (OA)-induced circadian desynchrony, while Cry, Nrf2, and HO-1 remain oblivious of melatonin treatment that was also validated by circwave analysis. C57BL/6J mice subjected to HFHF and/or JL, and treated with melatonin showed an improvement in the profile of lipid regulatory genes (CPT-1, PPARa, and SREBP-1c), liver function (AST and ALT) and histomorphology of fatty liver. A detailed scrutiny revealed that hepatic mRNA and protein profiles of Bmal1 (at ZT6) and Clock (at ZT12) underwent corrective changes in oscillations, but moderate corrections were recorded in other…

Dysfunction of the lymphatic system is associated with a wide range of disease phenotypes. The restoration of dysfunctional lymphatic vessels has been hypothesized as an innovative method to rescue healthy phenotypes in diseased states including neurological conditions, metabolic syndromes, and cardiovascular disease. Compared to the vascular system, little is known about the molecular regulation that controls lymphatic tube morphogenesis. Using synthetic hyaluronic acid (HA) hydrogels as a chemically and mechanically tunable system to preserve lymphatic endothelial cell (LECs) phenotypes, we demonstrate that low matrix elasticity primes lymphatic cord-like structure (CLS) formation directed by a high concentration of vascular endothelial growth factor-C (VEGF-C). Decreasing the substrate stiffness results in the upregulation of key lymphatic markers, including PROX-1, lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), and VEGFR-3. Consequently, higher levels of VEGFR-3 enable stimulation of LECs with VEGF-C which is required to both activate matrix metalloproteinases…

Abstract The degree that maternal glycemia affects placental metabolism of trophoblast cell types [cytotrophoblast (CTB) and syncytiotrophoblast (SCT)] in pregnant persons with gestational diabetes mellitus (GDM) is unknown. We tested the hypotheses that (a) hyperglycemia suppresses the metabolic rates of CTB and SCT; and (b) low placental metabolic activity from GDM placentas is due to decreased oxygen consumption of CTB. Trophoblast cells isolated from GDM and non‐GDM term placentas were cultured for 8‐hour (CTB) and following syncytialization at 72‐hour (SCT) in 5 mM of glucose or 25 mM of glucose. Oxygen consumption rates, glycolysis, ATP levels, and lipid droplet morphometries were determined in CTB and SCT. In CTB from GDM placentas compared to control CTB: (a) oxidative phosphorylation was decreased by 44% (41.8 vs 74.2 pmol O 2 /min/100 ng DNA, P = .002); (b) ATP content was 39% lower (1.1 × 10 −7 vs 1.8 × 10 −7 nM/ng DNA, P = .046); and (c) lipid droplets were two times larger (31.0 vs 14.4 µm 2 /cell, P < .001) and 1.7 times more numerous (13.5 vs 7.9 lipid droplets/cell,…

Resistance training (RT) dynamically alters the skeletal muscle nuclear DNA methylome. However, no study has examined if RT affects the mitochondrial DNA (mtDNA) methylome. Herein, ten older, Caucasian untrained males (65 ± 7 y.o.) performed six weeks of full-body RT (twice weekly). Body composition and knee extensor torque were assessed prior to and 72 h following the last RT session. Vastus lateralis (VL) biopsies were also obtained. VL DNA was subjected to reduced representation bisulfite sequencing providing excellent coverage across the ~16-kilobase mtDNA methylome (254 CpG sites). Biochemical assays were also performed, and older male data were compared to younger trained males (22 ± 2 y.o., n = 7, n = 6 Caucasian & n = 1 African American). RT increased whole-body lean tissue mass (p = .017), VL thickness (p = .012), and knee extensor torque (p = .029) in older males. RT also affected the mtDNA methylome, as 63% (159/254) of the CpG sites demonstrated reduced methylation (p < .05). Several mtDNA sites presented a more "youthful" signature in older males after RT in comparison…

Extracellular matrix (ECM) plays an important role in the progression of cancer. Collagen is the most abundant component in ECM, and it is involved in the biological formation of cancer. Although type XI collagen is a minor fibrillar collagen, collagen XI alpha 1 chain (COL11A1) has been found to be upregulated in a variety of cancers including ovarian cancer, breast cancer, thyroid cancer, pancreatic cancer, non-small-cell lung cancer, and transitional cell carcinoma of the bladder. High levels of COL11A1 usually predict poor prognosis, while COL11A1 is related to angiogenesis, invasion, and drug resistance of cancer. However, little is known about the specific mechanism by which COL11A1 regulates tumor progression. Here, we have organized and summarized the recent developments regarding elucidation of the relationship between COL11A1 and various cancers, as well as the interaction between COL11A1 and intracellular signaling pathways. In addition, we have selected therapeutic agents targeting COL11A1. All these indicate the possibility of using COL11A1 as a target for cancer…

Granulosa cells (GCs) are regulated by various factors during ovarian development. However, there are few reports on the role of follicular fluid exosomes in ovarian GCs. In this study, porcine ovarian GCs were used to explore the effects of follicular fluid exosomes on GCs. GCs were treated with in vitro, and the changes in cell proliferation, steroid synthesis, and associated signal pathways were detected. The results showed that exosomes increased cell viability and altered the gene expression profile of GCs. Exosomes also increased the level of gene expression associated with both proliferation and progesterone synthesis, in which the MAPK/ERK and WNT/B-CATENIN pathways were involved. In addition, exosome-carried microRNAs were identified by high-throughput sequencing, and exosomal miR-31-5p was found to promote the proliferation of GCs and progesterone synthesis via the WNT/B-CATENIN pathway by targeting the SFRP4 follicle growth inhibitor. In conclusion, this study has demonstrated that exosomes are essential substances involved in regulating the physiological function of GCs.

The liver is the only visceral organ in the body with a tremendous capacity to regenerate in response to insults that induce inflammation, cell death, and injury. Liver regeneration is a complicated process involving a well-orchestrated activation of non-parenchymal cells in the injured area and proliferation of undamaged hepatocytes. Furthermore, the liver has a Hepatostat, defined as adjustment of its volume to that required for homeostasis. Understanding the mechanisms that control different steps of liver regeneration is critical to informing therapies for liver repair, to help patients with liver disease. The Hippo signaling pathway is well known for playing an essential role in the control and regulation of liver size, regeneration, stem cell self-renewal, and liver cancer. Thus, the Hippo pathway regulates dynamic cell fates in liver, and in absence of its downstream effectors YAP and TAZ, liver regeneration is severely impaired, and the proliferative expansion of liver cells blocked. We will mainly review upstream mechanisms activating the Hippo signaling pathway following…

Aging is associated with gradual changes in liver structure and physiological/pathological functions in hepatic cells including hepatocytes, cholangiocytes, Kupffer cells, hepatic stellate cells (HSCs), and liver sinusoidal endothelial cells (LSECs). LSECs are specialized hepatic endothelial cells that regulate liver homeostasis. These cells actively impact the hepatic microenvironment as they have fenestrations and a thin morphology to allow substance exchange between circulating blood and the liver tissue. As aging occurs, LSECs have a reduction in both the number and size of fenestrations, which is referred to as pseudocapillarization. This along with the aging of the liver leads to increased oxidative stress, decreased availability of nitric oxide, decreased hepatic blood flow, and increased inflammatory cytokines in LSECs. Vascular aging can also lead to hepatic hypoxia, HSC activation, and liver fibrosis. In this review, we described the basic structure of LSECs, and the effect of LSECs on hepatic inflammation and fibrosis during aging process. We briefly summarized the…

Patterns of diurnal activity differ substantially between individuals, with early risers and late sleepers being examples of opposite chronotypes. Growing evidence suggests that the late chronotype significantly impacts the risk of developing mood disorders, obesity, diabetes, and other chronic diseases. Despite the vast potential of utilizing chronotype information for precision medicine, those factors that shape chronotypes remain poorly understood. Here, we assessed whether the various chronotypes are associated with different gut microbiome compositions. Using metagenomic sequencing analysis, we established a distinct signature associated with chronotype based on two bacterial genera, Alistipes (elevated in "larks") and Lachnospira (elevated in "owls"). We identified three metabolic pathways associated with the early chronotype, and linked distinct dietary patterns with different chronotypes. Our work demonstrates an association between the gut microbiome and chronotype and may represent the first step towards developing dietary interventions aimed at ameliorating the…

The SARS-CoV-2 pandemic imposed a large burden on health and society. Therapeutics targeting different components and processes of the viral infection replication cycle are being investigated, particularly to repurpose already approved drugs. Spike protein is an important target for both vaccines and therapeutics. Insights into the mechanisms of spike-ACE2 binding and cell fusion could support the identification of compounds with inhibitory effects. Here, we demonstrate that the integrity of disulfide bonds within the receptor-binding domain (RBD) plays an important role in the membrane fusion process although their disruption does not prevent binding of spike protein to ACE2. Several reducing agents and thiol-reactive compounds are able to inhibit viral entry. N-acetyl cysteine amide, L-ascorbic acid, JTT-705, and auranofin prevented syncytia formation, viral entry into cells, and infection in a mouse model, supporting disulfides of the RBD as a therapeutically relevant target.

Skin cancer patients often have tumorigenic lesions on their noses. Surgical resection of the lesions often results in nasal cartilage removal. Cartilage grafts taken from other anatomical sites are used for the surgical reconstruction of the nasal cartilage, but donor-site morbidity is a common problem. Autologous tissue-engineered nasal cartilage grafts can mitigate the problem, but commercially available scaffolds define the shape and sizes of the engineered grafts during tissue fabrication. Moreover, the engineered grafts suffer from the inhomogeneous distribution of the functional matrix of cartilage. Advances in 3D bioprinting technology offer the opportunity to engineer cartilages with customizable dimensions and anatomically shaped configurations without the inhomogeneous distribution of cartilage matrix. Here, we report the fidelity of Freeform Reversible Embedding of Suspended Hydrogel (FRESH) bioprinting as a strategy to generate customizable and homogenously distributed functional cartilage matrix engineered nasal cartilage. Using FRESH and in vitro chondrogenesis, we…

Abstract Inflammation in arterial walls leads to coronary artery disease (CAD). We previously reported that a high omega‐3 fatty index was associated with prevention of progression of coronary atherosclerosis, a disease of chronic inflammation in the arterial wall. However, the mechanism of such benefit is unclear. The two main omega‐3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are precursors of specialized pro‐resolving lipid mediators (SPMs)–resolvins and maresins–which actively resolve chronic inflammation. To explore whether SPMs are associated with coronary plaque progression, levels of SPMs and proinflammatory mediators (leukotriene B 4 [LTB 4 ] and prostaglandins) were measured using liquid chromatography‐tandem mass spectrometry in 31 statin‐treated patients with stable CAD randomized to either EPA and DHA, 3.36 g daily, or no EPA/DHA (control). Coronary plaque volume was measured by coronary computed tomographic angiography at baseline and at 30‐month follow‐up. Higher plasma levels of EPA+DHA were associated with significantly increased levels…

Numerous rodent studies demonstrate developmental programming of offspring cognition by maternal choline intake, with prenatal choline deprivation causing lasting adverse effects and supplemental choline producing lasting benefits. Few human studies have evaluated the effect of maternal choline supplementation on offspring cognition, with none following children to school age. Here, we report results from a controlled feeding study in which pregnant women were randomized to consume 480 mg choline/d (approximately the Adequate Intake [AI]) or 930 mg choline/d during the 3rd trimester. Sustained attention was assessed in the offspring at age 7 years (n = 20) using a signal detection task that showed benefits of maternal choline supplementation in a murine model. Children in the 930 mg/d group showed superior performance (vs. 480 mg/d group) on the primary endpoint (SAT score, p = .02) and a superior ability to maintain correct signal detections (hits) across the 12-min session (p = .02), indicative of improved sustained attention. This group difference in vigilance decrement varied by…

Diabetic brains are more vulnerable to ischemia-reperfusion injury. Previous studies have proved that melatonin could protect against cerebral ischemia-reperfusion (CIR) injury in non-diabetic stroke models; however, its roles and the underlying mechanisms against CIR injury in diabetic mice remain unknown. Streptozotocin-induced diabetic mice and high-glucose-cultured HT22 cells were exposed to melatonin, with or without administration of the autophagy inhibitor 3-methyladenine (3-MA) and the specifically silent information regulator 1 (SIRT1) inhibitor EX527, and then subjected to CIR or oxygen-glucose deprivation/reperfusion operation. We found that diabetic mice showed aggravated brain damage, increased apoptosis and oxidative stress, and deficient autophagy following CIR compared with non-diabetic counterparts. Melatonin treatment exhibited improved histological damage, neurological outcomes, and cerebral infarct size. Intriguingly, melatonin markedly increased cell survival, anti-oxidative and anti-apoptosis effects, and significantly enhanced autophagy. However, these effects…

The contribution of circulatory tau and β-amyloid in Parkinson's disease (PD), especially the cognitive function, remains inconclusive. Extracellular vesicles (EVs) cargo these proteins throughout the bloodstream after they are directly secreted from many cells, including neurons. The present study aims to investigate the role of the plasma EV-borne tau and β-amyloid as biomarkers for cognitive dysfunction in PD by investigating subjects with mild to moderate stage of PD (n = 116) and non-PD controls (n = 46). Plasma EVs were isolated, and immunomagnetic reduction-based immunoassay was used to assess the levels of α-synuclein, tau, and β-amyloid 1-42 (Aβ1-42) within the EVs. Artificial neural network (ANN) models were then applied to predict cognitive dysfunction. We observed no significant difference in plasma EV tau and Aβ1-42 between PD patients and controls. Plasma EV tau was significantly associated with cognitive function. Moreover, plasma EV tau and Aβ1-42 were significantly elevated in PD patients with cognitive impairment when compared to PD patients with optimal cognition.…

Damage to the cervical epithelial layer due to infection and inflammation is associated with preterm birth. However, the individual and/or collective roles of cervical epithelial layers in maintaining cervical integrity remain unclear during infection/inflammation. To determine the intercellular interactions, we developed an organ-on-chip of the cervical epithelial layer (CE-OOC) composed of two co-culture chambers connected by microchannels, recapitulating the ectocervical and endocervical epithelial layers. Further, we tested the interactions between cells from each distinct region and their contributions in maintaining cervical integrity in response to LPS and TNFα stimulations. The co-culture of ectocervical and endocervical cells facilitated cellular migration of both epithelial cells inside the microchannels. Compared to untreated controls, both LPS and TNFα increased apoptosis, necrosis, and senescence as well as increased pro-inflammatory cytokine productions by cervical epithelial cells. In summary, the CE-OOC established an in vitro model that can recapitulate the…

Abstract Besides its oncotic power, albumin exerts pleiotropic actions, including binding, transport, and detoxification of endogenous and exogenous molecules, antioxidant activity, and modulation of immune and inflammatory responses. In particular, recent studies have demonstrated that albumin reduces leukocyte cytokine production. Here, we investigated whether albumin also has the ability to protect tissues from the damaging actions of these inflammatory mediators. We circumscribed our investigation to tumor necrosis factor (TNF) α, which exemplifies the connection between immunity and tissue injury. In vivo experiments in analbuminemic mice showed that these mice exhibit a more pronounced response to a model of TNFα‐mediated liver injury induced by the administration of lipopolysaccharide (LPS) and D‐galactosamine (D‐gal). A tissue protective action against LPS/D‐gal liver injury was also observed during the administration of human albumin to humanized mice expressing the human genes for albumin and neonatal Fc receptor (h Alb +/+ /h FcRn +/+ ) with preestablished carbon…

Mounting evidence has linked the metabolic disease to neurovascular disorders and cognitive decline. Using a murine model of a high-fat high-sugar diet mimicking obesity-induced type 2 diabetes mellitus (T2DM) in humans, we show that pro-inflammatory mediators and altered immune responses damage the blood-brain barrier (BBB) structure, triggering a proinflammatory metabolic phenotype. We find that disruption to tight junctions and basal lamina due to loss of control in the production of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) causes BBB impairment. Together the disruption to the structural and functional integrity of the BBB results in enhanced transmigration of leukocytes across the BBB that could contribute to an initiation of a neuroinflammatory response through activation of microglia. Using a humanized in vitro model of the BBB and T2DM patient post-mortem brains, we show the translatable applicability of our results. We find a leaky BBB phenotype in T2DM patients can be attributed to a loss of junctional proteins through changes in inflammatory mediators…

Ammonia is one of the major metabolites produced by intestinal microorganisms; however, its role in intestinal homeostasis is poorly understood. The present study investigated the regulation of intestinal tight junction (TJ) proteins by ammonia and the underlying mechanisms in human intestinal Caco-2 cells. Ammonia (15, 30, and 60 mM) increased the permeability of the cells in a dose-dependent manner, as indicated by reduced transepithelial electrical resistance and increased dextran flux. Immunoblot and immunofluorescence analyses revealed that the ammonia-induced increase in TJ permeability reduced the membrane localization of TJ proteins such as zonula occludens (ZO)1, ZO2, occludin, claudin-1, and claudin-3. DNA microarray analysis identified a biological pathway "response to reactive oxygen species" enriched by ammonia treatment, indicating the induction of oxidative stress in the cells. Ammonia treatment also increased the malondialdehyde content and decreased the ratio of reduced to oxidized glutathione. Meanwhile, ammonia treatment-induced mitochondrial dysfunction, as…

Abstract Nonresponse, or acquired resistance to immune checkpoint inhibitors in colorectal cancer (CRC) highlight the importance of finding potential tolerance mechanisms. Low expression of major histocompatibility complex, class I (MHC‐I) on the cell surface of the tumor is one of the main mechanisms of tumor escape from T‐cell recognition and destruction. In this study, we demonstrated that a high level of calnexin (CANX) in the tumors is positively correlated with the overall survival in colorectal cancer patients. CANX is a chaperone protein involved in the folding and assembly of MHC‐I molecules. Using miRNA target prediction databases and luciferase assays, we identified miR‐148a‐3p as a potential regulator of CANX. Inhibition of miR‐148a‐3p restores surface levels of MHC‐I and significantly enhanced the effects of CD8 + T‐cell‐mediated immune attack in vitro and in vivo by promoting CANX expression. These results reveal that miR‐148a‐3p can function as a tumor promotor in CRC by targeting the CANX/MHC‐I axis, which provides a rationale for immunotherapy through targeting the…

Neutrophil trafficking is a key component of the inflammatory response. Here, we have investigated the role of the immunomodulatory lectin Galectin-9 (Gal-9) on neutrophil recruitment. Our data indicate that Gal-9 is upregulated in the inflamed vasculature of RA synovial biopsies and report the release of Gal-9 into the extracellular environment following endothelial cell activation. siRNA knockdown of endothelial Gal-9 resulted in reduced neutrophil adhesion and neutrophil recruitment was significantly reduced in Gal-9 knockout mice in a model of zymosan-induced peritonitis. We also provide evidence for Gal-9 binding sites on human neutrophils; Gal-9 binding induced neutrophil activation (increased expression of β2 integrins and reduced expression of CD62L). Intra-vital microscopy confirmed a pro-recruitment role for Gal-9, with increased numbers of transmigrated neutrophils following Gal-9 administration. We studied the role of both soluble and immobilized Gal-9 on human neutrophil recruitment. Soluble Gal-9 significantly strengthened the interaction between neutrophils and the…

Cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway has emerged as a key DNA-sensing machinery in innate immunity. Activation of cGAS-STING signaling pathway mediates the production of interferons and proinflammatory cytokines. Although cGAS-STING signaling pathway shows critical function in the maintenance of gut homeostasis, overactive cGAS-STING signaling pathway leads to gastrointestinal (GI) inflammation. Harnessing the effect and mechanism of the cGAS-STING signaling pathway could be beneficial for the development of novel strategies for the treatment of GI diseases. This review presents recent advances regarding the role of cGAS-STING signaling pathway in GI inflammatory disease and cancers and describes perspective therapeutic strategies targeting the signaling pathway.

Impaired mitochondrial fusion, due in part to decreased mitofusin 2 (Mfn2) expression, contributes to unrestricted cell proliferation and apoptosis-resistance in hyperproliferative diseases like pulmonary arterial hypertension (PAH) and non-small cell lung cancer (NSCLC). We hypothesized that Mfn2 levels are reduced due to increased proteasomal degradation of Mfn2 triggered by its phosphorylation at serine 442 (S442) and investigated the potential kinase mediators. Mfn2 expression was decreased and Mfn2 S442 phosphorylation was increased in pulmonary artery smooth muscle cells from PAH patients and in NSCLC cells. Mfn2 phosphorylation was mediated by PINK1 and protein kinase A (PKA), although only PINK1 expression was increased in these diseases. We designed a S442 phosphorylation deficient Mfn2 construct (PD-Mfn2) and a S442 constitutively phosphorylated Mfn2 construct (CP-Mfn2). The effects of these modified Mfn2 constructs on Mfn2 expression and biological function were compared with those of the wildtype Mfn2 construct (WT-Mfn2). WT-Mfn2 increased Mfn2 expression and…

Abstract The purpose of this study is to determine whether moderate aerobic exercise training improves high‐fat diet‐induced alterations in mitochondrial function and structure in the skeletal muscle. Male 4‐week‐old C57BL/6 mice were randomly divided into four groups: control (CON), control plus exercise (CON + EX), high‐fat diet (HFD), and high‐fat diet plus exercise (HFD + EX). After obesity was induced by 20 weeks of 60% HFD, treadmill exercise training was performed at 13‐16 m/min, 40‐50 min/day, and 6 days/week for 12 weeks. Mitochondrial structure, function, and dynamics, and mitophagy were analyzed in the skeletal muscle fibers from the red gastrocnemius. Exercise training increased mitochondrial number and area and reduced high‐fat diet‐induced obesity and hyperglycemia. In addition, exercise training attenuated mitochondrial dysfunction in the permeabilized myofibers, indicating that HFD‐induced decrease of mitochondrial O 2 respiration and Ca 2+ retention capacity and increase of mitochondrial H 2 O 2 emission were attenuated in the HFD + EX group compared to the HFD…

Protein misfolding is a central feature of most neurodegenerative diseases. Molecular chaperones can modulate the toxicity associated with protein misfolding, but it remains elusive which molecular chaperones and co-chaperones interact with specific misfolded proteins. TDP-43 misfolding and inclusion formation are a hallmark of amyotrophic lateral sclerosis (ALS) and other neurodegenerative diseases. Using yeast and mammalian neuronal cells we find that Hsp90 and its co-chaperone Sti1 have the capacity to alter TDP-43 misfolding, inclusion formation, aggregation, and cellular toxicity. Our data also demonstrate that impaired Hsp90 function sensitizes cells to TDP-43 toxicity and that Sti1 specifically interacts with and strongly modulates TDP-43 toxicity in a dose-dependent manner. Our study thus uncovers a previously unrecognized tie between Hsp90, Sti1, TDP-43 misfolding, and cellular toxicity.

For metastasis formation, individual cells from a primary tumor must migrate toward other tissues. The aim of this study was to determine if mesenchymal stromal cells (MSCs) from human bone marrow are able to emit signals that induce this migratory activity in cancer cells. We separated the supernatant of MSCs derived from human bone marrow by size-exclusion and ion-exchange chromatography and have subsequently studied the migratory behavior of the prostate cancer cell line PC3 and the breast cancer cell line MDA-MB-231 toward the respective fractions in a transwell migration assay. We identified the extracellular matrix (ECM) proteins type I collagen, type III collagen, fibronectin, and laminin 421 as potential drivers of cancer cell migration. These results could be reproduced using the corresponding isolated or recombinant ECM proteins. Knockdown of the gene encoding beta 1 integrin, an important cell surface receptor for fibronectin, has led to inhibition of cancer cell migration. This supports the hypothesis that beta 1 integrin signaling represents an initial event that leads…

The impact of sex and menopausal status in Alzheimer's disease remains understudied despite increasing evidence of greater female risk, particularly in APOE4 carriers. Utilizing female APOE-TR mice maintained on a high-fat diet background we induced ovarian failure through repeated VCD injections, to mimic human menopause. At 12 months of age, recognition memory and spatial memory were assessed using object recognition, Y-maze spontaneous alternation, and Barnes maze. A VCD*genotype interaction reduced the recognition memory (P < .05), with APOE4 VCD-treated animals unable to distinguish between novel and familiar objects. APOE4 mice displayed an additional 37% and 12% reduction in Barnes (P < .01) and Y-maze (P < .01) performance, indicative of genotype-specific spatial memory impairment. Molecular analysis indicated both VCD and genotype-related deficits in synaptic plasticity with BDNF, Akt, mTOR, and ERK signaling compromised. Subsequent reductions in the transcription factors Creb1 and Atf4 were also evident. Furthermore, the VCD*genotype interaction specifically diminished…

Pancreatic cancer (PaCa) is characterized by dense stroma that hinders treatment efficacy, with pancreatic stellate cells (PSCs) being a major contributor to this stromal barrier and PaCa progression. Activated PSCs release hepatocyte growth factor (HGF) and insulin-like growth factor (IGF-1) that induce PaCa proliferation, metastasis and resistance to chemotherapy. We demonstrate for the first time that the metastasis suppressor, N-myc downstream regulated gene 1 (NDRG1), is a potent inhibitor of the PaCa-PSC cross-talk, leading to inhibition of HGF and IGF-1 signaling. NDRG1 also potently reduced the key driver of PaCa metastasis, namely GLI1, leading to reduced PSC-mediated cell migration. The novel clinically trialed anticancer agent, di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC), which upregulates NDRG1, potently de-sensitized PaCa cells to ligands secreted by activated PSCs. DpC and NDRG1 also inhibited the PaCa-mediated activation of PSCs via inhibition of sonic hedgehog (SHH) signaling. In vivo, DpC markedly reduced PaCa tumor growth and metastasis more…

GAPDH, a heme chaperone, has been previously implicated in the incorporation of heme into iNOS and soluble guanylyl cyclase (sGC). Since sGC is critical for myoglobin (Mb) heme-maturation, we investigated the role of GAPDH in the maturation of this globin, as well as hemoglobins α, β, and γ. Utilizing cell culture systems, we found that overexpression of wild-type GAPDH increased, whereas GAPDH mutants H53A and K227A decreased, the heme content of Mb and Hbα and Hbβ. Overexpression of wild-type GAPDH fully recovered the heme-maturation inhibition observed with the GAPDH mutants. Partial rescue was observed by overexpression of sGCβ1 but not by overexpression of a sGCΔβ1 deletion mutant, which is unable to bind the sGCα1 subunit required to form the active sGCα1β1 complex. Wild type and mutant GAPDH was found to be associated in a complex with each of the globins and Hsp90. GAPDH at endogenous levels was found to be associated with Mb in differentiating C2C12 myoblasts, and with Hbγ or Hbα in differentiating HiDEP-1 erythroid progenitor cells. Knockdown of GAPDH in C2C12 cells…

Defective permeability barrier is considered to be an incentive of hyperuricemia, however, the link between them has not been proven. Here, we evaluated the potential preventive effects of Lactiplantibacillus plantarum N-1 (LPN1) on gut microbiota and intestinal barrier function in rats with hyperoxaluria-induced kidney stones. Male rats were supplied with 1% ethylene glycol (EG) dissolved in drinking water for 4 weeks to develop hyperoxaluria, and some of them were administered with LPN1 for 4 weeks before EG treatment as a preventive intervention. We found that EG not only resulted hyperoxaluria and kidney stone formation, but also promoted the intestinal inflammation, elevated intestinal permeability, and gut microbiota disorders. Supplementation of LPN1 inhibited the renal crystalline deposits through reducing urinary oxalic acid and renal osteopontin and CD44 expression and improved EG-induced intestinal inflammation and barrier function by decreasing the serum LPS and TLR4/NF-κB signaling and up-regulating tight junction Claudin-2 in the colon, as well as increasing the…

In recent years, it has become apparent that the gut microbiome can influence the functioning and pathological states of organs and systems throughout the body. In this study, we tested the hypothesis that the gut microbiome has a major role in the disruption of the blood-brain barrier (BBB) in the spontaneously hypertensive stroke prone rats (SHRSP), an animal model for hypertensive cerebral small vessel disease (CSVD). Loss of BBB is thought to be an early and initiating component to the full expression of CSVD in animal models and humans. To test this hypothesis, newly born SHRSP pups were placed with foster dams of the SHRSP strain or dams of the WKY strain, the control strain that does not demonstrate BBB dysfunction or develop hypertensive CSVD. Similarly, WKY pups were placed with foster dams of the same or opposite strain. The rationale for cross fostering is that the gut microbiomes are shaped by environmental bacteria of the foster dam and the nesting surroundings. Analysis of the bacterial genera in feces, using 16S rRNA analysis, demonstrated that the gut microbiome in…

Abstract Brown adipose tissue (BAT) dysfunction in aging and obesity has been related to chronic unresolved inflammation, which could be mediated by an impaired production of specialized proresolving lipid mediators (SPMs), such as Lipoxins‐LXs, Resolvins‐Rvs, Protectins‐PDs, and Maresins‐MaRs. Our aim was to characterize the changes in BAT SPMs signatures and their association with BAT dysfunction during aging, especially under obesogenic conditions, and their modulation by a docosahexaenoic acid (DHA)‐rich diet. Lipidomic, functional, and molecular studies were performed in BAT of 2‐ and 18‐month‐old lean (CT) female mice and in 18‐month‐old diet‐induced obese (DIO) mice fed with a high‐fat diet (HFD), or a DHA‐enriched HFD. Aging downregulated Prdm16 and UCP1 levels, especially in DIO mice, while DHA partially restored them. Arachidonic acid (AA)‐derived LXs and DHA‐derived MaRs and PDs were the most abundant SPMs in BAT of young CT mice. Interestingly, the sum of LXs and of PDs were significantly lower in aged DIO mice compared to young CT mice. Some of the SPMs most…

Abstract Cannabidiol (CBD), a phytocannabinoid from the Cannabis sativa plant, exhibits a broad spectrum of potential therapeutic properties for neurodegenerative diseases. An accumulation of amyloid‐β (Aβ) protein is one of the most important neuropathology in neurodegenerative diseases like Alzheimer's disease (AD). Data on the effect of CBD on the amelioration of Aβ‐induced neurite degeneration and its consequences of life and health spans is sparse. This study aimed to investigate the effects of CBD on neurite outgrowth in cells and lifespan and health span in Caenorhabditis elegans ( C . elegans ). In human SH‐SY5Y neuronal cells, CBD prevented neurite lesion induced by Aβ 1‐42 and increased the expression of fatty acid amide hydrolase (FAAH) and cannabinoid receptor 1 (CB1R). Furthermore, CBD both protected the reduction of dendritic spine density and rescued the activity of synaptic Ca 2+ /calmodulin‐dependent protein kinase II (CaMKII) from Aβ 1‐42 toxicity in primary hippocampal neurons. In C . elegans , we used the transgenic CL2355 strain of C . elegans , which expresses…

Maintaining ovarian steroidogenesis is of critical importance, considering that steroid hormones are required for successful establishment and maintenance of pregnancy and proper development of embryos and fetuses. Investigating the mechanism that butyrate modulates the ovarian steroidogenesis is beneficial for understanding the impact of lipid nutrition on steroidogenesis. Herein, we identified that butyrate improved estradiol and progesterone synthesis in rat primary ovarian granulosa cells and human granulosa KGN cells and discovered the related mechanism. Our data indicated that butyrate was sensed by GPR41 and GPR43 in ovarian granulosa cells. Butyrate primarily upregulated the acetylation of histone H3K9 (H3K9ac). Chromatin immune-precipitation and sequencing (ChIP-seq) data of H3K9ac revealed the influenced pathways involving in the mitochondrial function (including cellular metabolism and steroidogenesis) and cellular antioxidant capacity. Additionally, increasing H3K9ac by butyrate further stimulated the PPARγ/CD36/StAR pathways to increase ovarian steroidogenesis and…

Back and neck pain are significant healthcare burdens that are commonly associated with pathologies of the intervertebral disc (IVD). The poor understanding of the cellular heterogeneity within the IVD makes it difficult to develop regenerative IVD therapies. To address this gap, we developed an atlas of bovine (Bos taurus) caudal IVDs using single-cell RNA-sequencing (scRNA-seq). Unsupervised clustering resolved 15 unique clusters, which we grouped into the following annotated partitions: nucleus pulposus (NP), outer annulus fibrosus (oAF), inner AF (iAF), notochord, muscle, endothelial, and immune cells. Analyzing the pooled gene expression profiles of the NP, oAF, and iAF partitions allowed us to identify novel markers for NP (CP, S100B, H2AC18, SNORC, CRELD2, PDIA4, DNAJC3, CHCHD7, and RCN2), oAF (IGFBP6, CTSK, LGALS1, and CCN3), and iAF (MGP, COMP, SPP1, GSN, SOD2, DCN, FN1, TIMP3, WDR73, and GAL) cells. Network analysis on subpopulations of NP and oAF cells determined that clusters NP1, NP2, NP4, and oAF1 displayed gene expression profiles consistent with cell survival,…

Macrophages are the principal innate immune cells that populate all major organs and provide the first line of cellular defense against infections and/or injuries. The immediate and early-responding macrophages must mount a robust pro-inflammatory response to protect the host by eliminating deleterious agents. The effective pro-inflammatory macrophage response requires the activation of complex transcriptional programs that modulate the dynamic regulation of inflammatory and metabolic gene expression. Therefore, transcription factors that govern pro-inflammatory and metabolic gene expression play an essential role in shaping the macrophage inflammatory response. Herein, we identify the basic helix-loop-helix family member e40 (BHLHE40), as a critical transcription factor that promotes broad pro-inflammatory and glycolytic gene expression by elevating HIF1α levels in macrophages. Our in vivo studies revealed that myeloid-BHLHE40 deficiency significantly attenuates macrophage and neutrophil recruitment to the site of inflammation. Our integrated transcriptomics and gene set enrichment…

ABSTRACT Chemical neurotransmission in the brain typically occurs through synapses, which are structurally and functionally defined as sites of close apposition between an axon terminal and a postsynaptic domain. Ultrastructural examinations of axon terminals established by monoamine neurons in the brain often failed to identify a similar tight pre- and postsynaptic coupling, giving rise to the concept of “diffuse” or “volume” transmission. Whether this results from intrinsic properties of such modulatory neurons remains undefined. Using an efficient co-culture model, we find that dopaminergic neurons establish an axonal arbor that is distinctive compared to glutamatergic or GABAergic neurons in both size and propensity of terminals to avoid direct contact with target neurons. Furthermore, while most dopaminergic varicosities express key proteins involved in exocytosis such as synaptotagmin 1, only ~20% of these are synaptic. The active zone protein bassoon was found to be enriched in a subset of dopaminergic terminals that are in proximity to a target cell. Irrespective of their…

Breast cancer is a malignancy arising in the mammary epithelial tissues. Recent studies have indicated the abundance of microRNAs (miRNAs) in extracellular vesicles (EVs), and their interactions have been illustrated to exert crucial roles in the cell-to-cell communication. The present study focused on investigating whether EV-delivered miR-370-3p affects breast cancer. Initially, the miR-370-3p expression pattern was examined in the cancer-associated fibroblasts (CAFs), normal fibroblasts (NFs), and cancerous cells-derived EVs. The relation of miR-370-3p to CYLD was assessed using luciferase activity assay. Afterwards, based on ectopic expression and depletion experiments in the MCF-7 breast cancer cells, we evaluated stemness, migration, invasion, and sphere formation ability, and EMT, accompanied with measurement on the expression patterns of pro-inflammatory factors and nuclear factor-kappa B (NF-κB) signaling-related genes. Finally, tumorigenesis and proliferation were analyzed in vivo using a nude mouse xenograft model. The in vitro experiments revealed that breast cancer…

The preimplantation period of embryonic development can be a key window for programming of postnatal development because extensive epigenetic remodeling occurs during this time. It was hypothesized that modification of one-carbon metabolism of the bovine embryo by addition of the methyl-donor choline to culture medium would change postnatal phenotype through epigenetic modification. Embryos produced in vitro were cultured with 1.8 mM choline chloride or control medium. Blastocysts were transferred into females and pregnancy outcomes and postnatal phenotype of the resultant calves determined. Exposure of embryos to choline increased gestation length and calf birth weight. Calves derived from choline-treated embryos were also heavier at weaning and had increased ratio of body weight to hip height than control calves. Choline altered muscle DNA methylation of calves 4 months after birth. A total of 670 of the 8149 CpG examined were differentially methylated, with the predominant effect of choline being hypomethylation. Among the genes associated with differentially methylated CpG were…

The mitochondria-associated membrane (MAM) is a functional subdomain of the endoplasmic reticulum membrane that tethers to the mitochondrial outer membrane and is essential for cellular homeostasis. A defect in MAM is involved in various neurological diseases, including amyotrophic lateral sclerosis (ALS). Recently, we and others reported that MAM was disrupted in the models expressing several ALS-linked genes, including SOD1, SIGMAR1, VAPB, TARDBP, and FUS, suggesting that MAM disruption is deeply involved in the pathomechanism of ALS. However, it is still uncertain whether MAM disruption is a common pathology in ALS, mainly due to the absence of a simple, quantitative tool for monitoring the status of MAM. In this study, to examine the effects of various ALS-causative genes on MAM, we created the following two novel MAM reporters: MAMtracker-Luc and MAMtracker-Green. The MAMtrackers could detect MAM disruption caused by suppression of SIGMAR1 or the overexpression of ALS-linked mutant SOD1 in living cells. Moreover, the MAMtrackers have an advantage in their ability to monitor…

Abstract During episodes of acute inflammation, polymorphonuclear leukocytes (PMNs) are actively recruited to sites of inflammation or injury where they provide anti‐microbial and wound‐healing functions. One enzyme crucial for fulfilling these functions is myeloperoxidase (MPO), which generates hypochlorous acid from Cl − and hydrogen peroxide. The potential exists, however, that uncontrolled the extracellular generation of hypochlorous acid by MPO can cause bystander tissue damage and inhibit the healing response. Previous work suggests that the microbiota‐derived tryptophan metabolites 1 H ‐indole and related molecules (“indoles”) are protective during intestinal inflammation, although their precise mechanism of action is unclear. In the present work, we serendipitously discovered that indoles are potent and selective inhibitors of MPO. Using both primary human PMNs and recombinant human MPO in a cell‐free system, we revealed that indoles inhibit MPO at physiologic concentrations. Particularly, indoles block the chlorinating activity of MPO, a reliable marker for MPO‐associated…

Discovering safe and effective drugs that promote neuron regeneration is an essential strategy for the recovery of central nervous system injuries. In this study, we found that L-leucine, an essential amino acid obtained from both supplements and food sources, could dramatically boost axonal outgrowth and regeneration. First, the effects of L-leucine on neurons were evaluated by cell apoptosis, survival, and death assays, and the results showed no changes in these processes after treatment. By live cell imaging, L-leucine was found to remarkably increase axonal length and growth velocity after axotomy. We also verified that L-leucine enhanced p-mTOR/p-S6K activation in neurons by testing with an mTOR inhibitor, rapamycin. Thereafter, we investigated the effects of L-leucine on the spinal cord injury in vivo. A mouse model of spinal cord hemi-section was established, and L-leucine was administered by tail intravenous injection. Basso mouse scale values revealed that L-leucine could improve functional recovery after injury. It was also notable that L-leucine treatment promoted axon…

Inflammatory bowel disease (IBD) remains a persistent health problem with a global burden surging over 6.8 million cases currently. Clinical pathology of IBD is complicated; however, hyperactive inflammatory and immune responses in the gut is shown to be one of the persistent causes of the disease. Human gut inflammasome, the activator of innate immune system is believed to be a primary underlying cause for the pathology and is largely associated with the progression of IBD. To manage IBD, there is a need to fully understand the role of inflammasome activation in IBD. Since inflammasome potentially play a significant role in IBD, systemic modulation of inflammasome may provide an effective therapeutic and clinical approach to control IBD symptoms. In this review, we have focused on this association between IBD and gut inflammasome, and recent advances in the research and therapeutic strategies for IBD. We have discussed inflammasomes and their components, outcomes from the experimental animals and human studies, inflammasome inhibitors, and developments in the inflammasome-targeted…

Abstract Constitutively expressed by innate immune cells, the cytokine macrophage migration inhibitory factor (MIF) initiates host immune responses and drives pathogenic responses in infectious, inflammatory, and autoimmune diseases. Dendritic cells (DCs) express high levels of MIF, but the role of MIF in DC function remains poorly characterized. As migration is critical for DC immune surveillance, we investigated whether MIF promoted the migration of DCs. In classical transwell experiments, MIF −/− bone marrow‐derived DCs (BMDCs) or MIF +/+ BMDCs treated with ISO‐1, an inhibitor of MIF, showed markedly reduced spontaneous migration and chemotaxis. CD74 −/− BMDCs that are deficient in the ligand‐binding component of the cognate MIF receptor exhibited a migration defect similar to that of MIF −/− BMDCs. Adoptive transfer experiments of LPS‐matured MIF +/+ and MIF −/− and of CD74 +/+ and CD74 −/− BMDCs injected into the hind footpads of homologous or heterologous mice showed that the autocrine and paracrine MIF activity acting via CD74 contributed to the recruitment of DCs to the…

Abstract Neuroprotective and other functional proteins of mitochondria were quantified in extracts of plasma neural‐derived exosomes from ten first‐episode psychosis (FP) patients and ten matched psychiatrically normal controls (ctls). Astrocyte‐derived extracellular vesicles (ADEVs) and neuron‐derived extracellular vesicles (NDEVs) were immunoabsorbed separately from physically precipitated plasma total EVs. Extracted mitochondrial ATP synthase was specifically immunofixed to plastic wells for quantification of catalytic activity based on conversion of NADH to NAD + . Other extracted mitochondrial functional proteins were quantified by ELISAs. All protein levels were normalized with EV content of the CD81 exosome marker. FP patient ADEV level but not NDEV level of mitochondrial ATP synthase activity was significantly lower than that of ctls. FP patient ADEV and NDEV levels of the functionally critical mitochondrial proteins mitofusin 2 and cyclophilin D, but not of transcription factor A of mitochondria, and of the mitochondrial short open‐reading frame neuroprotective and…

Abstract In humans, insulin resistance has been linked to an impaired metabolic transition from fasting to feeding (metabolic flexibility; MetFlex). Previous studies suggest that mitochondrial dynamics response is a putative determinant of MetFlex; however, this has not been studied in humans. Thus, the aim of this study was to investigate the mitochondrial dynamics response in the metabolic transition from fasting to feeding in human peripheral blood mononuclear cells (PBMCs). Six male subjects fasted for 16 h (fasting), immediately after which they consumed a 75‐g oral glucose load (glucose). In both fasting and glucose conditions, blood samples were taken to obtain PBMCs. Mitochondrial dynamics were assessed by electron microscopy images. We exposed in vitro acetoacetate‐treated PBMCs to the specific IP3R inhibitor Xestospongin B (XeB) to reduce IP3R‐mediated mitochondrial Ca 2+ accumulation. This allowed us to evaluate the role of ER‐mitochondria Ca 2+ exchange in the mitochondrial dynamic response to substrate availability. To determine whether PBMCs could be used in obesity…

The ability to form a variety of cell-matrix connections is crucial for angiogenesis to take place. Without stable anchorage to the extracellular matrix (ECM), endothelial cells (ECs) are unable to sense, integrate and disseminate growth factor stimulated responses that drive growth of a vascular bed. Neuropilin-2 (NRP2) is a widely expressed membrane-bound multifunctional non-tyrosine kinase receptor, which has previously been implicated in influencing cell adhesion and migration by interacting with α5-integrin and regulating adhesion turnover. α5-integrin, and its ECM ligand fibronectin (FN) are both known to be upregulated during the formation of neo-vasculature. Despite being descriptively annotated as a candidate biomarker for aggressive cancer phenotypes, the EC-specific roles for NRP2 during developmental and pathological angiogenesis remain unexplored. The data reported here support a model whereby NRP2 actively promotes EC adhesion and migration by regulating dynamic cytoskeletal remodeling and by stimulating Rab11-dependent recycling of α5-integrin-p-FAK complexes to newly…

Abstract Hypertension is associated with excessive reactive oxygen species (ROS) production in vascular cells. Mitochondria undergo fusion and fission, a process playing a role in mitochondrial function. OPA1 is essential for mitochondrial fusion. Loss of OPA1 is associated with ROS production and cell dysfunction. We hypothesized that mitochondria fusion could reduce oxidative stress that defect in fusion would exacerbate hypertension. Using (a) Opa1 haploinsufficiency in isolated resistance arteries from Opa1 +/− mice, (b) primary vascular cells from Opa1 +/− mice, and (c) RNA interference experiments with siRNA against Opa1 in vascular cells, we investigated the role of mitochondria fusion in hypertension. In hypertension, Opa1 haploinsufficiency induced altered mitochondrial cristae structure both in vascular smooth muscle and endothelial cells but did not modify protein level of long and short forms of OPA1. In addition, we demonstrated an increase of mitochondrial ROS production, associated with a decrease of superoxide dismutase 1 protein expression. We also observed an…

Renal fibrosis leads to chronic kidney disease, which affects over 15% of the U.S. population. PAI-1 is highly upregulated in the tubulointerstitial compartment in several common nephropathies and PAI-1 global ablation affords protection from fibrogenesis in mice. The precise contribution of renal tubular PAI-1 induction to disease progression, however, is unknown and surprisingly, appears to be independent of uPA inhibition. Human renal epithelial (HK-2) cells engineered to stably overexpress PAI-1 underwent dedifferentiation (E-cadherin loss, gain of vimentin), G2/M growth arrest (increased p-Histone3, p21), and robust induction of fibronectin, collagen-1, and CCN2. These cells are also susceptible to apoptosis (elevated cleaved caspase-3, annexin-V positivity) compared to vector controls, demonstrating a previously unknown role for PAI-1 in tubular dysfunction. Persistent PAI-1 expression results in a loss of klotho expression, p53 upregulation, and increases in TGF-βRI/II levels and SMAD3 phosphorylation. Ectopic restoration of klotho in PAI-1-transductants attenuated…

Macrophages and other immune cells are important contributors to obesity-associated inflammation; however, the cellular identities of these specific populations remain unknown. In this study, we identified individual populations of myeloid cells found in mouse epididymal/visceral adipose tissue by single-cell RNA sequencing, immunofluorescence, and flow cytometry. Multiple canonical correlation analysis identified 11 unique myeloid and myeloid-associate cell populations. In obese mice, we detected an increased percentage of monocyte-derived pro-inflammatory cells expressing Cd9 and Trem2, as well as significantly decreased percentages of multiple cell populations, including tissue-resident cells expressing Lyve1, Mafb, and Mrc1. We have identified and validated a novel myeloid/macrophage population defined by Ly6a expression, exhibiting both myeloid and mesenchymal characteristics, which increased with obesity and showed high pro-fibrotic characteristics in vitro. Our mouse adipose tissue myeloid cell atlas provides an important resource to investigate obesity-associated…

Atherosclerosis is a chronic inflammatory disease of the arterial wall. It has been known that development of atherosclerosis is closely related to activation of tumor necrosis factor α (TNF-α). The objective of this study was to elucidate the effects of TNF-α blockade with brusatol on endothelial activation under pro-atherosclerotic conditions. To this end, we examined the effects of brusatol on TNF-α-induced intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression in human aortic endothelial cells (HAECs) using western blot and THP-1 adhesion assays. Brusatol induced a decrease in TNF-α-induced ICAM-1 and VCAM-1 expression through inhibiting TNFR1 expression, leading to suppression of endothelial inflammation independently of the NRF2 (nuclear factor erythroid 2-related factor 2) pathway. The mechanism underlying brusatol-induced TNF receptor 1 (TNFR1) inhibition was investigated with the aid of protein synthesis, co-immunoprecipitation, and cytokine arrays. Notably, brusatol inhibited TNFR1 protein synthesis and suppressed both the…

Epilepsy is a common brain disorder, repeated seizures of epilepsy may lead to a series of brain pathological changes such as neuronal or glial damage. However, whether circular RNAs are involved in neuronal injury during epilepsy is not fully understood. Here, we screened circIgf1r in the status epilepticus model through circRNA sequencing, and found that it was upregulated after the status epilepticus model through QPCR analysis. Astrocytes polarizing toward neurotoxic A1 phenotype and neurons loss were observed after status epilepticus. Through injecting circIgf1r siRNA into the lateral ventricle, it was found that knocking down circIgf1r in vivo would induce the polarization of astrocytes to phenotype A2 and reduce neuronal loss. The results in vitro further confirmed that inhibiting the expression of circIgf1r in astrocytes could protect neurons by converting reactive astrocytes from A1 to the protective A2. In addition, knocking down circIgf1r in astrocytes could functionally promote astrocyte autophagy and relieve the destruction of 4-AP-induced autophagy flux. In terms of…

Abstract Exercise training exerts protective effects against diabetic nephropathy. This study aimed to investigate whether exercise training could attenuate diabetic renal injury via regulating endogenous hydrogen sulfide (H 2 S) production. First, C57BL/6 mice were allocated into the control, diabetes, exercise, and diabetes + exercise groups. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ). Treadmill exercise continued for four weeks. Second, mice was allocated into the control, diabetes, H 2 S and diabetes + H 2 S groups. H 2 S donor sodium hydrosulfide (NaHS) was intraperitoneally injected once daily for four weeks. STZ‐induced diabetic mice exhibited glomerular hypertrophy, tissue fibrosis and increased urine albumin levels, urine protein‐ and albumin‐to‐creatinine ratios, which were relieved by exercise training. Diabetic renal injury was associated with apoptotic cell death, as evidenced by the enhanced caspase‐3 activity, the increased TdT‐mediated dUTP nick‐end labeling ‐positive cells and the reduced expression of anti‐apoptotic proteins, all of…

Adolescent idiopathic scoliosis (AIS) is a common spinal deformity characterized by changes in the three-dimensional structure of the spine. It usually initiates during puberty, the peak period of human growth when the secretion of numerous hormones is changing, and it is more common in females than in males. Accumulating evidence shows that the abnormal levels of many hormones including estrogen, melatonin, growth hormone, leptin, adiponectin and ghrelin, may be related to the occurrence and development of AIS. The purpose of this review is to provide a summary and critique of the research published on each hormone over the past 20 years, and to highlight areas for future study. It is hoped that the presentation will help provide a better understanding of the role of endocrine hormones in the pathogenesis of AIS.

Ubiquitination is an essential post-translational modification that regulates protein stability or function. Its substrate specificity is dictated by various E3 ligases. The human C-terminal to LisH (CTLH) complex is a newly discovered multi-subunit really interesting new gene (RING) E3 ligase with only a few known ubiquitination targets. Here, we used mass spectrometry-based proteomic techniques to gain insight into CTLH complex function and ubiquitination substrates in HeLa cells. First, global proteomics determined proteins that were significantly increased, and thus may be substrates targeted for degradation, in cells depleted of CTLH complex member RanBPM. RanBPM-dependent ubiquitination determined using diGLY-enriched proteomics and the endogenous RanBPM interactome further revealed candidate ubiquitination targets. Three glycolysis enzymes alpha-enolase, L-lactate dehydrogenase A chain (LDHA), and pyruvate kinase M1/2 (PKM) had decreased ubiquitin sites in shRanBPM cells and were found associated with RanBPM in the interactome. Reduced polyubiquitination was validated for…

FUT2, a protein that uses l-fucose to mediate fucosylation of intestinal epithelial cells, is one of the detected gene variants in IBD patients. We aimed to investigate whether exogenous l-fucose could be an enteral nutritional supplement to protect intestinal barrier function. The effect of l-fucose on the restoration of epithelial barrier function in both the DSS-induced colitis mouse model and LPS-stimulated Caco-2 cells was investigated, and the impact on fucosylation of epithelial cells was examined. The severity of DSS-induced colitis was significantly reduced by l-fucose. Restoration of epithelial barrier function by l-fucose was detected. Direct l-fucose-mediated protection of tight junctions was observed in Caco-2 cells. Moreover, exogenous l-fucose promoted the exogenous metabolic pathway of l-fucose, and fucosylation of epithelial cells both in vivo and in vitro. Moreover, knockout of the FUT2 gene restrained fucosylation and the protective effect of l-fucose on barrier function. The severity of colitis was not improved by l-fucose in Fut2 knockout mice. Therefore we…

Endotherms in cold regions improve heat-producing capacity when preparing for winter. We know comparatively little about how this change is fueled by seasonal adaptation in cellular respiration. Thus, we studied the changes of mitochondrial function in red blood cells in sympatric Coal (Periparus ater), Blue (Cyanistes caeruleus), and Great (Parus major) tits between autumn and winter. These species differ more than twofold in body mass and in several aspects of their foraging ecology and social dominance, which could require differential seasonal adaptation of energy expenditure. Coal and Great tits in particular upregulated the mitochondrial respiration rate and mitochondrial volume in winter. This was not directed toward ATP synthesis, instead reflecting increased uncoupling of electron transport from ATP production. Because uncoupling is exothermic, this increased heat-producing capacity at the sub-cellular level in winter. This previously unexplored the route of thermogenesis in birds should be addressed in future work.

Abstract Mitochondrial remodeling through fusion and fission is crucial for progenitor cell differentiation but its role in myogenesis is poorly understood. Here, we characterized the function of mitofusin 2 (Mfn2), a mitochondrial outer membrane protein critical for mitochondrial fusion, in muscle progenitor cells (myoblasts). Mfn2 expression is upregulated during myoblast differentiation in vitro and muscle regeneration in vivo. Targeted deletion of Mfn2 gene in myoblasts ( Mfn2 MKO ) increases oxygen‐consumption rates (OCR) associated with the maximal respiration and spare respiratory capacity, and increased levels of reactive oxygen species (ROS). Skeletal muscles of Mfn2 MKO mice exhibit robust mitochondrial swelling with normal mitochondrial DNA content. Additionally, mitochondria isolated from Mfn2 MKO muscles have reduced OCR at basal state and for complex I respiration, associated with decreased levels of complex I proteins NDUFB8 (NADH ubiquinone oxidoreductase subunit B8) and NDUFS3 (NADH ubiquinone oxidoreductase subunit S3). However, Mfn2 MKO has no obvious effects on…

UV irradiation can injure the epidermis, resulting in sunburn, inflammation, and cutaneous tissue disorders. Previous studies demonstrate that EGFR in keratinocytes can be activated by UVB and contributes to inflammation. Poly (ADP-ribose) polymerase-1 (PARP-1) is a nuclear enzyme and plays an essential role in DNA repair under moderate stress. In this study, we set out to understand how PARP-1 regulates UVB irradiation-induced skin injury and interplays with EGFR to mediate the inflammation response. We found that PARP-1 deficiency exacerbated the UVB-induced inflammation, water loss, and back skin damage in mice. In human primary keratinocytes, UVB can activate PARP-1 and enhance DNA damage upon PARP-1 gene silencing. Moreover, PARP-1 silencing and PARP inhibitor olaparib can suppress UVB-induced COX-2 and MMP-1 expression, but enhance TNF-α and IL-8 expression. In addition, EGFR silencing or EGFR inhibition by gefitinib can decrease UVB-induced COX-2, TNF-α, and IL-8 expression, suggesting EGFR activation via paracrine action can mediate UVB-induced inflammation responses.…

Treatment of respiratory viral infections remains a global health concern, mainly due to the inefficacy of available drugs. Therefore, the discovery of novel antiviral compounds is needed; in this context, antimicrobial peptides (AMPs) like temporins hold great promise. Here, we discovered that the harmless temporin G (TG) significantly inhibited the early life-cycle phases of influenza virus. The in vitro hemagglutinating test revealed the existence of TG interaction with the viral hemagglutinin (HA) protein. Furthermore, the hemolysis inhibition assay and the molecular docking studies confirmed a TG/HA complex formation at the level of the conserved hydrophobic stem groove of HA. Remarkably, these findings highlight the ability of TG to block the conformational rearrangements of HA2 subunit, which are essential for the viral envelope fusion with intracellular endocytic vesicles, thereby neutralizing the virus entry into the host cell. In comparison, in the case of parainfluenza virus, which penetrates host cells upon a membrane-fusion process, addition of TG to infected cells…

Abstract Androgen excess is one of the most common endocrine disorders of reproductive‐aged women, affecting up to 20% of this population. Women with elevated androgens often exhibit hyperinsulinemia and insulin resistance. The mechanisms of how elevated androgens affect metabolic function are not clear. Hyperandrogenemia in a dihydrotestosterone (DHT)‐treated female mouse model induces whole body insulin resistance possibly through activation of the hepatic androgen receptor (AR). We investigated the role of hepatocyte AR in hyperandrogenemia‐induced metabolic dysfunction by using several approaches to delete hepatic AR via animal‐, cell‐, and clinical‐based methodologies. We conditionally disrupted hepatocyte AR in female mice developmentally (LivARKO) or acutely by tail vein injection of an adeno‐associated virus with a liver‐specific promoter for Cre expression in AR fl/fl mice (adLivARKO). We observed normal metabolic function in littermate female Control (AR fl/fl ) and LivARKO (AR fl/fl ; Cre +/− ) mice. Following chronic DHT treatment, female Control mice treated with DHT…

Bullous pemphigoid (BP), an autoimmune skin disease, is characterized by autoantibodies against hemidesmosomal proteins in the skin and mucous membranes. Neutrophils infiltrate BP skin lesions, however, their role in immune dysregulation remains unclear. We investigated whether BP involves aberrant neutrophil extracellular traps (NETs) formation in skin lesions and circulation; and examined the triggers and deleterious immuno-inflammatory consequences. In the present study, we found that circulating NET-related biomarker levels increased in serum and blister fluid of BP patients and significantly correlated with disease severity. Additionally, circulating neutrophils from BP patients displayed enhanced spontaneous NETs formation than healthy controls. In vitro, BP180-NC16A immune complexes-induced NETosis in neutrophils from BP patients, which was abrogated by Fcγ receptor and/or NADPH pathway blockade. Furthermore, the elevated levels of NETs from BP patients boosted autoantibody production by inducing B-cell differentiation into plasma cells, mediated by MAPK P38 cascade…

Neuroinflammation is recognized as a hallmark of spinal cord injury (SCI). Although neuroinflammation is an important pathogenic factor that leads to secondary injuries after SCI, neuroprotective anti-inflammatory treatments remain ineffective in the management of SCI. Moreover, the molecular signatures involved in the pathophysiological changes that occur during the course of SCI remain ambiguous. The current study investigated the proteins and pathways involved in C5 spinal cord hemi-contusion injury using a rat model by means of 4-D label-free proteomic analysis. Furthermore, two Gene Expression Omnibus (GEO) transcriptomic datasets, Western blot assays, and immunofluorescent staining were used to validate the expression levels and localization of dysregulated proteins. The present study observed that the rat models of SCI were associated with the enrichment of proteins related to the complement and coagulation cascades, cholesterol metabolism, and lysosome pathway throughout the acute and subacute phases of injury. Intriguingly, the current study also observed that 75 genes were…