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Phenotype switch of vascular smooth muscle cells (VSMCs) plays an important role in the development of atherosclerosis (AS). Endothelial cells can regulate VSMC phenotypic switch by secreting exosomes, crucial mediators of intracellular communication. This study aimed to determine whether exosomal LINC01005 from oxidized low-density lipoprotein (ox-LDL)-treated human umbilical vein endothelial cells (HUVECs) plays a role in regulating VSMC phenotypic switch and to validate the underlying molecular mechanism. Exosomes were extracted from ox-LDL-treated HUVECs (ox-LDL-Exo) and then administered into VSMCs. VSMC phenotypic switch was assessed by determining VSMC phenotypic markers using western blot. VSMC cell proliferation and migration were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and wound healing assay, respectively. The interaction between miR-128-3p and LINC01005 or Krüppel-like factor 4 (KLF4) was analyzed by luciferase reporter assay. ox-LDL-Exo contained high expression of LINC01005. Inhibition of LINC01005 expression in ox-LDL-Exo abrogated the ox-LDL-Exo-induced VSMC phenotypic switch, proliferation, and migration. Furthermore, LINC01005 acted as a sponge of miR-128-3p to upregulate KLF4 expression. Moreover, miR-128-3p overexpression and KLF4 silencing in VSMCs attenuated the ox-LDL-Exo-induced VSMC phenotypic switch, proliferation, and migration. Collectively, exosomal LINC01005 from ox-LDL-treated HUVECs promotes VSMC phenotype switch, proliferation, and migration by regulating the miR-128-3p/KLF4 axis.

Background Ginsenosides accumulation responses to temperature are critical to quality formation in cold-dependent American ginseng. However, the studies on cold requirement mechanism relevant to ginsenosides have been limited in this species. Methods Two experiments were carried out: one was a multivariate linear regression analysis between the ginsenosides accumulation and the environmental conditions of American ginseng from different sites of China and the other was a synchronous determination of ginsenosides accumulation, overall DNA methylation, and relative gene expression in different tissues during different developmental stages of American ginseng after experiencing different cold exposure duration treatments. Results Results showed that the variation of the contents as well as the yields of total and individual ginsenosides Rg1, Re, and Rb1 in the roots were closely associated with environmental temperature conditions which implied that the cold environment plays a decisive role in the ginsenoside accumulation of American ginseng. Further results showed that there is a cyclically reversible dynamism between methylation and demethylation of DNA in the perennial American ginseng in response to temperature seasonality. And sufficient cold exposure duration in winter caused sufficient DNA demethylation in tender leaves in early spring and then accompanied the high expression of flowering gene PqFT in flowering stages and ginsenosides biosynthesis gene PqDDS in green berry stages successively, and finally, maximum ginsenosides accumulation occurred in the roots of American ginseng. Conclusion We, therefore, hypothesized that cold-induced DNA methylation changes might regulate relative gene expression involving both plant development and plant secondary metabolites in such cold-dependent perennial plant species.

Background: Excessive salt intake is considered as an important risk factor for cognitive impairment, which might be the consequence of imbalanced intestinal homeostasis. Objective: To investigate the effects of dietary salt on the gut microbiota and cognitive performance and the underlying mechanisms. Methods: Adult female C57BL/6 mice were maintained on either normal chow (control group, CON) or sodium-rich chow containing 8% NaCl (high-salt diet, HSD) for 8 weeks. Spatial learning and memory ability, short-chain fatty acids (SCFAs) concentrations, gut bacterial flora composition, blood-brain barrier permeability, and proinflammatory cytokine levels and apoptosis in the brain were evaluated. Results: The mice fed a HSD for 8 weeks displayed impaired learning and memory abilities. HSD significantly reduced the proportions of Bacteroidetes (S24-7 and Alloprevotella) and Proteobacteria and increased that of Firmicutes (Lachnospiraceae and Ruminococcaceae). SCFA concentrations decreased in the absolute concentrations of acetate, propionate, and butyrate in the fecal samples from the HSD-fed mice. The HSD induced both BBB dysfunction and microglial activation in the mouse brain, and increased the IL-1β, IL-6, and TNF-α expression levels in the cortex. More importantly, the degree of apoptosis was higher in the cortex and hippocampus region of mice fed the HSD, and this effect was accompanied by significantly higher expression of cleaved caspase-3, caspase-3, and caspase-1. Conclusion: The HSD directly causes cognitive dysfunction in mice by eliciting an inflammatory environment and triggering apoptosis in the brain, and these effects are accompanied by gut dysbiosis, particularly reduced SCFA production.

BackgroundLeft-sided heart failure (HF) is documented as a key prognostic factor in HF. However, the relative molecular mechanisms underlying left-sided HF is unknown. The purpose of this study is to unearth significant modules, pivotal genes and candidate regulatory components governing the progression of left-sided HF by bioinformatical analysis.MethodsA total of 319 samples in GSE57345 dataset were used for weighted gene correlation network analysis (WGCNA). ClusterProfiler package in R was used to conduct functional enrichment for genes uncovered from the modules of interest. Regulatory networks of genes were built using Cytoscape while Enrichr database was used for identification of transcription factors (TFs). The MCODE plugin was used for identifying hub genes in the modules of interest and their validation was performed based on GSE1869 dataset.ResultsA total of six significant modules were identified. Notably, the blue module was confirmed as the most crucially associated with left-sided HF, ischemic heart disease (ISCH) and dilated cardiomyopathy (CMP). Functional enrichment conveyed that genes belonging to this module were mainly those driving the extracellular matrix-associated processes such as extracellular matrix structural constituent and collagen binding. A total of seven transcriptional factors, including Suppressor of Zeste 12 Protein Homolog (SUZ12) and nuclear factor erythroid 2 like 2 (NFE2L2), adrenergic receptor (AR), were identified as possible regulators of coexpression genes identified in the blue module. A total of three key genes (OGN, HTRA1 and MXRA5) were retained after validation of their prognostic value in left-sided HF. The results of functional enrichment confirmed that these key genes were primarily involved in response to transforming growth factor beta and extracellular matrix.ConclusionWe uncovered a candidate gene signature correlated with HF, ISCH and CMP in the left ventricle, which may help provide better prognosis and therapeutic decisions and in HF, ISCH and CMP patients.

CD4+ T cells are the central element of the adaptive immune responses and protect the body from a variety of pathogens. Starting from naive cells, CD4+ T cells can differentiate into various effector cell subsets with specialized functions including T helper (Th) 1, Th2, Th17, regulatory T (Treg) and T follicular helper (Tfh) cells. Among them, Tregs and Th17 cells show a strong plasticity allowing the functional adaptation to various physiological and pathological environments during immune responses. Although they are derived from the same precursor cells and their differentiation pathways are interrelated, the terminally differentiated cells have totally opposite functions. Studies have shown that Tregs and Th17 cells have rather complex interplays in viral infection: Th17 cells may contribute to immune activation and disease progression while Tregs may inhibit this process and play a key role in the maintenance of immune homoeostasis, possibly at the cost of compromised viral control. In this review, we take respiratory syncytial virus (RSV), hepatitis B virus (HBV)/hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections as examples to discuss these interplays and their impacts on disease progression in viral infection.

Given the growing evidence of a link between gut microbiota (GM) dysbiosis and multiple sclerosis (MS), fecal microbiota transplantation (FMT), aimed at rebuilding GM, has been proposed as a new therapeutic approach to MS treatment. To evaluate the viability of FMT for MS treatment and its impact on MS pathology, we tested FMT in mice with experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. We provide evidence that FMT can rectify altered GM to some extent with a therapeutic effect on EAE. We also found that FMT led to reduced activation of microglia and astrocytes and conferred protection on the blood-brain barrier (BBB), myelin, and axons in EAE. Taken together, our data suggest that FMT, as a GM-based therapy, has the potential to be an effective treatment for MS.

Mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) integrates various environmental signals to regulate cell growth and metabolism. DEPTOR, also termed DEPDC6, is an endogenous inhibitor of mTORC1 and mTORC2 activities. The abundance of DEPTOR centrally orchestrates the mTOR signaling network. However, the mechanisms by which DEPTOR stability is regulated are still elusive. Here, we report that OTU domain–containing ubiquitin aldehyde-binding protein 1 (OTUB1) specifically deubiquitinates DEPTOR in a deubiquitination assay. We found that OTUB1 directly interacted with DEPTOR via its N-terminal domain, deubiquitinated DEPTOR, and thereby stabilized DEPTOR in a Cys-91–independent but Asp-88–dependent manner, suggesting that OTUB1 targets DEPTOR for deubiquitination via a deubiquitinase activity–independent non-canonical mechanism. The interaction between OTUB1 and DEPTOR was enhanced when the cells were treated with amino acids. Moreover, OTUB1 suppressed amino acid–induced activation of mTORC1 in a DEPTOR-dependent manner and thereby ultimately controlled cellular autophagy, cell proliferation, and size. Our findings reveal a mechanism that stabilizes the mTORC1 inhibitor DEPTOR via OTUB1's deubiquitinase activity. Our insights may inform research into various mTOR activity–related diseases, such as cancer, and may contribute to the identification of new diagnostic markers and therapeutic strategies for cancer treatments.

Understanding the mechanisms of early cardiac fate determination may lead to better approaches in promoting heart regeneration. We used a mesoderm posterior 1 (Mesp1)-Cre/Rosa26-EYFP reporter system to identify microRNAs (miRNAs) enriched in early cardiac progenitor cells. Most of these miRNA genes bear MESP1-binding sites and active histone signatures. In a calcium transient-based screening assay, we identified miRNAs that may promote the cardiomyocyte program. An X-chromosome miRNA cluster, miR-322/-503, is the most enriched in the Mesp1 lineage and is the most potent in the screening assay. It is specifically expressed in the looping heart. Ectopic miR-322/-503 mimicking the endogenous temporal patterns specifically drives a cardiomyocyte program while inhibiting neural lineages, likely by targeting the RNA-binding protein CUG-binding protein Elav-like family member 1 (Celf1). Thus, early miRNAs in lineage-committed cells may play powerful roles in cell-fate determination by cross-suppressing other lineages. miRNAs identified in this study, especially miR-322/-503, are potent regulators of early cardiac fate.

Myotonic dystrophy 1 (DM1) is a common form of muscular dystrophy. Although several animal models have been established for DM1, myoblast cell models are still important because they offer an efficient cellular alternative for studying cellular and molecular events. Though C2C12 myoblast cells have been widely used to study myogenesis, resistance to gene transfection, or viral transduction, hinders research in C2C12 cells. Here, we describe an optimized protocol that includes daily maintenance, transfection and transduction procedures to introduce genes into C2C12 myoblasts and the induction of myocyte differentiation. Collectively, these procedures enable best transfection/transduction efficiencies, as well as consistent differentiation outcomes. The protocol described in establishing DM1 myoblast cell models would benefit the study of myotonic dystrophy, as well as other muscular diseases.

Summary YAP, a key effector of Hippo pathway, is activated by its translocation from cytoplasm to nucleus to regulate gene expression and promote tumorigenesis. Although the mechanism by which YAP is suppressed in cytoplasm has been well-studied, how the activated YAP is sequestered in the nucleus remains unknown. Here, we demonstrate that YAP is a nucleocytoplasmic shuttling protein and its nuclear export is controlled by SET1A-mediated mono-methylation of YAP at K342, which disrupts the binding of YAP to CRM1. YAP mimetic methylation knockin mice are more susceptible to colorectal tumorigenesis. Clinically, YAP K342 methylation is reversely correlated with cancer survival. Collectively, our study identifies SET1A-mediated mono-methylation at K342 as an essential regulatory mechanism for regulating YAP activity and tumorigenesis.