[Abstract unavailable

The anti-hyperglycemic effect of metformin is believed to be caused by its direct action on signaling processes in hepatocytes, leading to lower hepatic gluconeogenesis. Recently, metformin was reported to alter the gut microbiota community in humans, suggesting that the hyperglycemia-lowering action of the drug could be the result of modulating the population of gut microbiota. However, the critical microbial signaling metabolites and the host targets associated with the metabolic benefits of metformin remained elusive. Here, we performed metagenomic and metabolomic analysis of samples from individuals with newly diagnosed type 2 diabetes (T2D) naively treated with metformin for 3 d, which revealed that Bacteroides fragilis was decreased and the bile acid glycoursodeoxycholic acid (GUDCA) was increased in the gut. These changes were accompanied by inhibition of intestinal farnesoid X receptor (FXR) signaling. We further found that high-fat-diet (HFD)-fed mice colonized with B. fragilis were predisposed to more severe glucose intolerance, and the metabolic benefits of metformin treatment on glucose intolerance were abrogated. GUDCA was further identified as an intestinal FXR antagonist that improved various metabolic endpoints in mice with established obesity. Thus, we conclude that metformin acts in part through a B. fragilis–GUDCA–intestinal FXR axis to improve metabolic dysfunction, including hyperglycemia.

IMPORTANCE Uncertainty remains about the efficacy of folic acid therapy for the primary prevention of stroke because of limited and inconsistent data. OBJECTIVE To test the primary hypothesis that therapy with enalapril and folic acid is more effective in reducing first stroke than enalapril alone among Chinese adults with hypertension. DESIGN, SETTING, AND PARTICIPANTS The China Stroke Primary Prevention Trial, a randomized, double-blind clinical trial conducted from May 19, 2008, to August 24, 2013, in 32 communities in Jiangsu and Anhui provinces in China. A total of 20 702 adults with hypertension without history of stroke or myocardial infarction (MI) participated in the study. INTERVENTIONS Eligible participants, stratified by MTHFR C677T genotypes (CC, CT, and TT), were randomly assigned to receive double-blind daily treatment with a single-pill combination containing enalapril, 10 mg, and folic acid, 0.8 mg (n = 10 348) or a tablet containing enalapril, 10 mg, alone (n = 10 354). MAIN OUTCOMES AND MEASURES The primary outcome was first stroke. Secondary outcomes included first ischemic stroke; first hemorrhagic stroke; MI; a composite of cardiovascular events consisting of cardiovascular death, MI, and stroke; and all-cause death. RESULTS During a median treatment duration of 4.5 years, compared with the enalapril alone group, the enalapril-folic acid group had a significant risk reduction in first stroke (2.7% of participants in the enalapril-folic acid group vs 3.4% in the enalapril alone group; hazard ratio [HR], 0.79; 95% CI, 0.68-0.93), first ischemic stroke (2.2% with enalapril-folic acid vs 2.8% with enalapril alone; HR, 0.76; 95% CI, 0.64-0.91), and composite cardiovascular events consisting of cardiovascular death, MI, and stroke (3.1% with enalapril-folic acid vs 3.9% with enalapril alone; HR, 0.80; 95% CI, 0.69-0.92). The risks of hemorrhagic stroke (HR, 0.93; 95% CI, 0.65-1.34), MI (HR, 1.04; 95% CI, 0.60-1.82), and all-cause deaths (HR, 0.94; 95% CI, 0.81-1.10) did not differ significantly between the 2 treatment groups. There were no significant differences between the 2 treatment groups in the frequencies of adverse events. CONCLUSIONS AND RELEVANCE Among adults with hypertension in China without a history of stroke or MI, the combined use of enalapril and folic acid, compared with enalapril alone, significantly reduced the risk of first stroke. These findings are consistent with benefits from folate use among adults with hypertension and low baseline folate levels.

N6-methyladenosine (m6A) is the most abundant mRNA modification. With the development of antibody-based sequencing technologies and the findings of m6A-related “writers”, “erasers”, and “readers”, the relationships between m6A and mRNA metabolism are emerging. The m6A modification influences almost every step of RNA metabolism that comprises mRNA processing, mRNA exporting from nucleus to cytoplasm, mRNA translation, mRNA decay, and the biogenesis of long-non-coding RNA (lncRNA) and microRNA (miRNA). Recently, more and more studies have found m6A is associated with cancer, contributing to the self-renewal of cancer stem cell, promotion of cancer cell proliferation, and resistance to radiotherapy or chemotherapy. Inhibitors of m6A-related factors have been explored, and some of them were identified to inhibit cancer progression, indicating that m6A could be a target for cancer therapy. In this review, we are trying to summarize the regulation and function of m6A in human carcinogenesis.

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Single‐atom catalysts (SACs) are attracting widespread interest for the catalytic oxygen reduction reaction (ORR), with Fe−Nx SACs exhibiting the most promising activity. However, Fe‐based catalysts suffer serious stability issues as a result of oxidative corrosion through the Fenton reaction. Herein, using a metal‐organic framework as an anchoring matrix, we for the first time obtained pyrolyzed Cr/N/C SACs for the ORR, where the atomically dispersed Cr is confirmed to have a Cr−N4 coordination structure. The Cr/N/C catalyst exhibits excellent ORR activity with an optimal half‐wave potential of 0.773 V versus RHE. More excitingly, the Fenton reaction is substantially reduced and, thus, the final catalysts show superb stability. The innovative and robust active site for the ORR opens a new possibility to circumvent the stability issue of the non‐noble metal ORR catalysts.

MicroRNAs (miRNAs) are a group of small noncoding RNAs (ncRNAs) that posttranscriptionally regulate gene expression by targeting their corresponding messenger RNAs (mRNAs). Dysregulated miRNAs have been considered as a new type of ‘‘oncomiRs” or ‘‘tumor suppressors,” playing essential roles in cancer initiation and progression. Using genome-wide detection methods, ubiquitously aberrant expression profiles of miRNAs have been identified in a broad array of human cancers, showing great potential as novel diagnostic and prognostic biomarkers of cancer with high specificity and sensitivity. The detectable miRNAs in tissue, blood, and other body fluids with high stability provide an abundant source for miRNA-based biomarkers in human cancers. Despite the fact that an increasing number of potential miRNA biomarkers have been reported, the transition of miRNAs-based biomarkers from bench to bedside still necessitates addressing several challenges. In this review, we will summarize our current understanding of miRNAs as potential biomarkers in human cancers.

Abstract-The migration of vascular smooth muscle cells (VSMCs) plays an essential role during the development of atherosclerosis and restenosis. Extensive studies have implicated the importance of extracellular matrix (ECM)-degrading proteinases in VSMC migration. A recently described family of proteinases, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTs), is capable of degrading vascular ECM proteins. Here, we sought to determine whether ADAMTS-7 is involved in VSMC migration and neointima formation in response to vascular injury. ADAMTS-7 protein accumulated preferentially in neointima of the carotid artery wall after balloon injury. In primary VSMCs, ADAMTS-7 level was enhanced by the proinflammatory cytokine tumor necrosis factor ␣ and growth factor platelet-derived growth factor-BB. ADAMTS-7 overexpression greatly accelerated and small interfering RNA knockdown markedly retarded VSMC migration/invasion in vitro. In addition, luminal delivery of ADAMTS-7 adenovirus to carotid arteries exacerbated intimal thickening nearly sixfold 7 days after injury. Conversely, perivascular administration of ADAMTS-7 small interfering RNA but not scramble small interfering RNA to injured arteries attenuated intimal thickening by 50% at 14 days after injury. Furthermore, ADAMTS-7 mediated degradation of the vascular ECM cartilage oligomeric matrix protein (COMP) in injured vessels. Replenishing COMP circumvented the promigratory effect of ADAMTS-7 on VSMCs. Enforced expression of COMP significantly suppressed VSMC migration and neointima formation postinjury, which indicates that ADAMTS-7 facilitated intimal hyperplasia through degradation of inhibitory matrix protein COMP. ADAMTS-7 may therefore serve as a novel therapeutic target for atherosclerosis and postangioplasty restenosis. Key Words: metalloproteinase Ⅲ vascular smooth muscle cell migration Ⅲ neointima formation Ⅲ extracellular matrix M edia-to-intima migration of vascular smooth muscle cells (VSMCs) is pivotal to intimal thickening in atherosclerosis, restenosis after coronary angioplasty, and late failure of vein grafting. 1 Normally VSMCs are quiescent and are surrounded by and embedded in an extracellular matrix (ECM) scaffold that acts as a barrier to VSMC migration. ECM degradation and remodeling require the activation of extracellular proteases, which in turn facilitate VSMC migration. 2 Previous studies have emphasized potential roles for the matrix metalloproteinases MMP-2, MMP-9, and MT1-MMP; the serine proteinases plasminogen activator and plasminogen; and the cysteine proteinases cathepsins K, L, and S during matrix remodeling and VSMC migration. 3 However, the identity of the matrix-degrading proteinases during pathological vascular remodeling in vivo has remained the subject of speculation.The recently identified metalloproteinase family of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) also degrade ECM. First identified in 1997, ADAMTS already showed strong biological relevance. 4 For example, ADAMTS...