Background: It is increasingly recognized that gut microbiota play a pivotal role in the development of atherosclerotic cardiovascular disease. Previously, we have reported that the abundance of genus Bacteroides is lower in patients with coronary artery disease (CAD) than in patients without CAD with coronary risk factors or in healthy volunteers. However, it remains unclear which and how specific gut bacteria contribute to the progression of atherosclerosis. Methods: We recruited patients with CAD patients and controls without CAD with coronary risk factors. We then compared gut microbial composition using 16S ribosomal RNA gene sequencing in fecal samples to detect species with differential abundance between 2 groups. Subsequently, we used atherosclerosis-prone mice to study the mechanisms underlying the relationship between such species and atherosclerosis. Results: Human fecal 16S ribosomal RNA gene sequencing revealed a significantly lower abundance of Bacteroides vulgatus and Bacteroides dorei in patients with CAD. This significant differential abundance was confirmed by quantitative polymerase chain reaction. Gavage with live B. vulgatus and B. dorei attenuated atherosclerotic lesion formation in atherosclerosis-prone mice, markedly ameliorating endotoxemia followed by decreasing gut microbial lipopolysaccharide production, effectively suppressing proinflammatory immune responses. Furthermore, fecal lipopolysaccharide levels in patients with CAD were significantly higher and negatively correlated with the abundance of B. vulgatus and B. dorei . Conclusions: Our translational research findings identify a previously unknown link between specific gut bacteria and atherosclerosis. Treatment with live B. vulgatus and B. dorei may help prevent CAD. Clinical Trial Registration: URL: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000018051 . Unique identifier: UMIN000015703.

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Objective-To determine whether the administration of an active form of vitamin D 3 (calcitriol) could prevent atherosclerosis through anti-inflammatory actions. Methods and Results-Recent clinical studies have shown that lack of vitamin D 3 is a risk factor for cardiovascular events.Oral calcitriol administration decreased atherosclerotic lesions, macrophage accumulation, and CD4 ϩ T-cell infiltration at the aortic sinus, when compared with the corresponding observations in control mice. We observed a significant increase in Foxp3 ϩ regulatory T cells and a decrease in CD80 ϩ CD86 ϩ dendritic cells (DCs) in the mesenteric lymph nodes, spleen, and atherosclerotic lesions in oral calcitriol-treated mice in association with increased interleukin 10 and decreased interleukin 12 mRNA expression. CD11cϩ DCs from the calcitriol group showed reduced proliferative activity of T lymphocytes, suggesting the suppression of DC maturation. Neutralization of CD25 in vivo revealed that calcitriol inhibited atherosclerosis mainly in a regulatory T cell-dependent manner but also partly because of a decrease in DC maturation. , is a secosteroid hormone that not only plays a central role in bone and calcium metabolism but also modulates the immune response. Recent epidemiological studies have shown a relationship between low plasma levels of vitamin D 3 and a predisposition to cardiovascular events. [1][2][3] This finding is supported by a meta-analysis showing that oral vitamin D 3 treatment contributes to the improvement of mortality from all causes, in part by decreasing cardiovascular deaths. 4 Transgenic rats constitutively expressing vitamin D-24-hydroxylase, a model of vitamin D 3 deficiency, showed aggravated atherosclerosis under a high-fat and high-cholesterol diet, when compared with control rats. 5 However, there are no reports about the direct effects of an orally administered active form of vitamin D 3 on atherosclerosis. Conclusion-Oral See accompanying article on page 2317It is widely recognized that atherosclerosis is a complex inflammatory disease of the arterial wall, 6,7 in which the T-lymphocyte-mediated pathogenic immune response plays a critical role. Clinical strategies developed to modulate the immune response have been insufficient for preventing atherosclerosis. Cumulative data based on experimental animal models suggest that CD4 ϩ T cells are present within plaques from the initial stages of the disease in mice, and adaptive transfer of these cells is potentially proatherogenic. 8 Accumulating evidence has revealed novel functions of several subsets of regulatory T cells (Tregs), which maintain immunologic tolerance to self-antigens and inhibit atherosclerosis development by suppressing the inflammatory response of effector T cells. 9 -12 These studies have provided new insights into the immunopathogenesis of atherosclerosis and imply that promotion of regulatory immune responses may have therapeutic potential for suppression of atherosclerotic diseases.In addition to Tregs, dendritic cells (DCs) are al...

Background-Accumulating evidence suggests that several subsets of regulatory T cells that actively mediate immunologic tolerance play crucial roles in atherogenesis. Recently, orally administered anti-CD3 monoclonal antibody has been shown as an inducer of novel regulatory T cells expressing latency-associated peptide (LAP) on their surface, which potently prevents systemic autoimmunity. In the present study, we hypothesized that oral anti-CD3 antibody treatment may inhibit atherosclerosis in mice. Methods and Results-Six-week-old apolipoprotein E-deficient mice on a standard diet were orally given anti-CD3 antibody or control immunoglobulin G on 5 consecutive days, and atherosclerosis was assessed at age 16 weeks. Oral administration of anti-CD3 antibody significantly reduced atherosclerotic lesion formation and accumulations of macrophages and CD4 ϩ T cells in the plaques compared with controls. We observed a significant increase in LAP ϩ cells and CD25ϩ Foxp3 ϩ cells in the CD4 ϩ T-cell population in anti-CD3-treated mice, in association with increased production of the antiinflammatory cytokine transforming growth factor-␤ and suppressed T-helper type 1 and type 2 immune responses. Neutralization of transforming growth factor-␤ in vivo abrogated the preventive effect of oral anti-CD3 antibody. Key Words: atherosclerosis Ⅲ immune system Ⅲ inflammation Ⅲ lymphocytes A therosclerosis is an inflammatory condition of the arterial wall involving cells of innate and adaptive immunity. 1,2 It leads to severe clinical events caused by the rupture of plaques and thrombotic occlusion of the artery and is the main cause of acute coronary syndrome and stroke, which account for approximately half of the deaths in Western countries. It is now widely recognized that chronic inflammation via T-cell-mediated pathogenic immune responses plays an important role in atherogenesis. 2 Accumulating evidence suggests that several subsets of regulatory T cells (Tregs), which have been shown to maintain immunologic unresponsiveness to self-antigens, 3 inhibit atherosclerosis development through the downregulation of activated T-cell responses. 4 -6 These studies imply that promotion of an endogenous regulatory immune response has a therapeutic potential to suppress atherosclerotic diseases. Conclusions-Our Clinical Perspective on p 2005Anti-CD3-specific antibodies strongly suppress immune responses by antigenic modulation of the T-cell receptor/CD3 complex. 7 In 1985, parenteral anti-CD3 antibody was available for use in acute transplant rejection in humans. However, its long-term use is limited because of severe side effects such as mitogenicity and antiglobulin responses. 7 The mitogenicity of anti-CD3 antibody with Fc portion is caused by interacting with Fc receptors (FcRs) on monocytes or macrophages. Therefore, humanized Fc-mutated antibodies were designed and demonstrated to be effective in human autoimmune diabetes for a long period, although they still induce low levels of cytokine release because of some degree of T-cell a...

The association between atherosclerosis and gut microbiota has been attracting increased attention. We previously demonstrated a possible link between gut microbiota and coronary artery disease. Our aim of this study was to clarify the gut microbiota profiles in coronary artery disease patients using data mining analysis of terminal restriction fragment length polymorphism (T-RFLP). This study included 39 coronary artery disease (CAD) patients and 30 age- and sex- matched no-CAD controls (Ctrls) with coronary risk factors. Bacterial DNA was extracted from their fecal samples and analyzed by T-RFLP and data mining analysis using the classification and regression algorithm. Five additional CAD patients were newly recruited to confirm the reliability of this analysis. Data mining analysis could divide the composition of gut microbiota into 2 characteristic nodes. The CAD group was classified into 4 CAD pattern nodes (35/39 = 90 %), while the Ctrl group was classified into 3 Ctrl pattern nodes (28/30 = 93 %). Five additional CAD samples were applied to the same dividing model, which could validate the accuracy to predict the risk of CAD by data mining analysis. We could demonstrate that operational taxonomic unit 853 (OTU853), OTU657, and OTU990 were determined important both by the data mining method and by the usual statistical comparison. We classified the gut microbiota profiles in coronary artery disease patients using data mining analysis of T-RFLP data and demonstrated the possibility that gut microbiota is a diagnostic marker of suffering from CAD.

The gut microbiota were shown to play critical roles in the development of atherosclerosis, but the detailed mechanism is limited. The purpose of this study is to clarify the influence of gut microbiota on atherogenesis via lipid metabolism and systemic inflammation. Germ-free or conventionally raised (Conv) ApoE-deficient (ApoE−/−) mice were fed chow diet and euthanized at 20 weeks of age. We found that the lack of gut microbiota in ApoE−/− mice caused a significant increase in the plasma and hepatic cholesterol levels compared with Conv ApoE−/− mice. The absence of gut microbiota changed the bile acid composition in the ileum, which was associated with activation of the enterohepatic fibroblast growth factor 15, fibroblast growth factor receptor 4 axis, and reduction of cholesterol 7α-hydroxylase and hepatic bile acid synthesis, resulting in the accumulation of liver cholesterol content. However, we found that the lack of microbiota caused a significant reduction in atherosclerotic lesion formation compared with Conv ApoE−/− mice, which might be associated with the attenuation of lipopolysaccharide-mediated inflammatory responses. Our findings indicated that the gut microbiota affected both hypercholesterolemia and atherogenesis in mice.

Background: Gut microbiome composition or circulating microbiome-related metabolites in patients with heart failure (HF) have not been investigated at different time points (i.e., in the decompensated (Decomp) and compensated (Comp) phases). Methods and Results: We prospectively enrolled 22 patients admitted for HF and 11 age-, sex-, and comorbidity-matched hospitalized control subjects without a history of HF. Gut flora and plasma microbiome-related metabolites were evaluated by amplicon sequencing of the bacterial 16S ribosomal RNA gene and capillary electrophoresis time-of-flight mass spectrometry, respectively. HF patients were evaluated in both the Decomp and Comp phases during hospitalization. The phylum Actinobacteria was enriched in HF patients compared with control subjects. At the genus level, Bifiodobacterium was abundant while Megamonas was depleted in HF patients. Meanwhile, plasma concentration of trimethylamine N-oxide (TMAO), a gut microbiome-derived metabolite, was increased in HF patients (Decomp HF vs. control, P=0.003; Comp HF vs. control, P=0.004). A correlation analysis revealed positive correlations between the abundance of the genus Escherichia/Shigella and levels of TMAO and indoxyl sulfate (IS, a microbe-dependent uremic toxin) in Comp HF (TMAO: r=0.62, P=0.002; IS: r=0.63, P=0.002). Escherichia/Shigella was more abundant in Decomp than in Comp HF (P=0.030). Conclusions: Our results suggest that gut microbiome composition and microbiome-related metabolites are altered in HF patients.

Vascular senescence is thought to play a crucial role in an ageing-associated decline of organ functions; however, whether vascular senescence is causally implicated in age-related disease remains unclear. Here we show that endothelial cell (EC) senescence induces metabolic disorders through the senescence-associated secretory phenotype. Senescence-messaging secretomes from senescent ECs induced a senescence-like state and reduced insulin receptor substrate-1 in adipocytes, which thereby impaired insulin signaling. We generated EC-specific progeroid mice that overexpressed the dominant negative form of telomeric repeat-binding factor 2 under the control of the Tie2 promoter. EC-specific progeria impaired systemic metabolic health in mice in association with adipose tissue dysfunction even while consuming normal chow. Notably, shared circulation with EC-specific progeroid mice by parabiosis sufficiently transmitted the metabolic disorders into wild-type recipient mice. Our data provides direct evidence that EC senescence impairs systemic metabolic health, and thus establishes EC senescence as a bona fide risk for age-related metabolic disease.