Colony stimulating factor-1 producing endothelial cells and mesenchymal stromal cells maintain monocytes within a perivascular bone marrow niche.

Macrophage colony stimulating factor-1 (CSF-1) plays a critical role in maintaining myeloid lineage cells. However, congenital global deficiency of CSF-1 (Csf1op/op) causes severe musculoskeletal defects that may indirectly affect hematopoiesis. Indeed, we show here that osteolineage-derived Csf1 prevented developmental abnormalities but had no effect on monopoiesis in adulthood. However, ubiquitous deletion of Csf1 conditionally in adulthood decreased monocyte survival, differentiation, and migration, independent of its effects on bone development. Bone histology revealed that monocytes reside near sinusoidal endothelial cells (ECs) and leptin receptor (Lepr)-expressing perivascular mesenchymal stromal cells (MSCs). Targeted deletion of Csf1 from sinusoidal ECs selectively reduced Ly6C- monocytes, whereas combined depletion of Csf1 from ECs and MSCs further decreased Ly6Chi cells. Moreover, EC-derived CSF-1 facilitated recovery of Ly6C- monocytes and protected mice from weight loss following induction of polymicrobial sepsis. Thus, monocytes are supported by distinct cellular sources of CSF-1 within a perivascular BM niche.

Single-Cell RNA Sequencing Reveals an Immune Landscape of CD4+ T Cells in Coronary Culprit Plaques With Acute Coronary Syndrome in Humans-Brief Report.

BACKGROUND: Acute coronary syndrome (ACS) involves plaque-related thrombosis, causing primary ischemic cardiomyopathy or lethal arrhythmia. We previously demonstrated a unique immune landscape of myeloid cells in the culprit plaques causing ACS by using single-cell RNA sequencing. Here, we aimed to characterize T cells in a single-cell level, assess clonal expansion of T cells, and find a therapeutic target to prevent ACS. METHODS: We obtained the culprit lesion plaques from 4 patients with chronic coronary syndrome (chronic coronary syndrome plaques) and the culprit lesion plaques from 3 patients with ACS (ACS plaques) who were candidates for percutaneous coronary intervention with directional coronary atherectomy. Live CD45+ immune cells were sorted from each pooled plaque samples and applied to the 10× platform for single-cell RNA sequencing analysis. We also extracted RNA from other 3 ACS plaque samples and conducted unbiased TCR (T-cell receptor) repertoire analysis. RESULTS: CD4+ T cells were divided into 5 distinct clusters: effector, naive, cytotoxic, CCR7+ (C-C chemokine receptor type 7) central memory, and FOXP3 (forkhead box P3)+ regulatory CD4+ T cells. The proportion of central memory CD4+ T cells was higher in the ACS plaques. Correspondingly, dendritic cells also tended to express more HLAs (human leukocyte antigens) and costimulatory molecules in the ACS plaques. The velocity analysis suggested the differentiation flow from central memory CD4+ T cells into effector CD4+ T cells and that from naive CD4+ T cells into central memory CD4+ T cells in the ACS plaques, which were not observed in the chronic coronary syndrome plaques. The bulk repertoire analysis revealed clonal expansion of TCRs in each patient with ACS and suggested that several peptides in the ACS plaques work as antigens and induced clonal expansion of CD4+ T cells. CONCLUSIONS: For the first time, we revealed single cell-level characteristics of CD4+ T cells in patients with ACS. CD4+ T cells could be therapeutic targets of ACS. REGISTRATION: URL: https://upload.umin.ac.jp/cgi-open-bin/icdr_e/ctr_view.cgi?recptno=R000046521; Unique identifier: UMIN000040747.

Radiation Impacts Early Atherosclerosis by Suppressing Intimal LDL Accumulation.

RATIONALE: Bone marrow transplantation (BMT) is used frequently to study the role of hematopoietic cells in atherosclerosis, but aortic arch lesions are smaller in mice after BMT. OBJECTIVE: To identify the earliest stage of atherosclerosis inhibited by BMT and elucidate potential mechanisms. METHODS AND RESULTS: Ldlr-/- mice underwent total body γ-irradiation, bone marrow reconstitution, and 6-week recovery. Atherosclerosis was studied in the ascending aortic arch and compared with mice without BMT. In BMT mice, neutral lipid and myeloid cell topography were lower in lesions after feeding a cholesterol-rich diet for 3, 6, and 12 weeks. Lesion coalescence and height were suppressed dramatically in mice post-BMT, whereas lateral growth was inhibited minimally. Targeted radiation to the upper thorax alone reproduced the BMT phenotype. Classical monocyte recruitment, intimal myeloid cell proliferation, and apoptosis did not account for the post-BMT phenotype. Neutral lipid accumulation was reduced in 5-day lesions, thus we developed quantitative assays for LDL (low-density lipoprotein) accumulation and paracellular leakage using DiI-labeled human LDL and rhodamine B-labeled 70 kD dextran. LDL accumulation was dramatically higher in the intima of Ldlr-/- relative to Ldlr+/+ mice, and was inhibited by injection of HDL mimics, suggesting a regulated process. LDL, but not dextran, accumulation was lower in mice post-BMT both at baseline and in 5-day lesions. Since the transcript abundance of molecules implicated in LDL transcytosis was not significantly different in the post-BMT intima, transcriptomics from whole aortic arch intima, and at single-cell resolution, was performed to give insights into pathways modulated by BMT. CONCLUSIONS: Radiation exposure inhibits LDL entry into the aortic intima at baseline and the earliest stages of atherosclerosis. Single-cell transcriptomic analysis suggests that LDL uptake by endothelial cells is diverted to lysosomal degradation and reverse cholesterol transport pathways. This reduces intimal accumulation of lipid and impacts lesion initiation and growth.

Bacteroides vulgatus and Bacteroides dorei Reduce Gut Microbial Lipopolysaccharide Production and Inhibit Atherosclerosis.

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.

UVB Exposure Prevents Atherosclerosis by Regulating Immunoinflammatory Responses.

OBJECTIVE: UVB irradiation is an established treatment for immunoinflammatory cutaneous disorders and has been shown to suppress cutaneous and systemic inflammatory diseases through modulation of the adaptive immune response. However, it remains unknown whether UVB irradiation prevents an immunoinflammatory disease of arteries such as atherosclerosis. APPROACH AND RESULTS: Here, we show that UVB exposure inhibits the development and progression of atherosclerosis in atherosclerosis-prone mice by expanding and enhancing the functional capacity of CD4+ forkhead box P3+ regulatory T cells and regulating proatherogenic T-cell responses. Experimental studies in Langerhans cell-depleted mice revealed that epidermal Langerhans cells play a critical role in UVB-dependent induction of CD4+ forkhead box P3+ regulatory T cells, suppression of proatherogenic T-cell responses, and prevention of atherosclerotic plaque development. CONCLUSIONS: Our findings suggest the skin immune system as a novel therapeutic target for atherosclerosis and provide a novel strategy for the treatment and prevention of atherosclerosis.

Gut Microbiome and Plasma Microbiome-Related Metabolites in Patients With Decompensated and Compensated Heart Failure.

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.

Commensal bacteria at the crossroad between cholesterol homeostasis and chronic inflammation in atherosclerosis.

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.

Impact of CD14++CD16+ monocytes on plaque vulnerability in diabetic and non-diabetic patients with asymptomatic coronary artery disease: a cross-sectional study.

BACKGROUND: Previously, we have reported that daily glucose fluctuations could affect coronary plaque vulnerability, but the underlying mechanisms remained unclear. This study sought to investigate the impact of CD14++CD16+ monocytes on plaque vulnerability, as assessed by virtual histology intravascular ultrasound (VH-IVUS), as well as their relationship to fluctuating glucose levels in patients with asymptomatic coronary artery disease (CAD). METHODS: Fifty-one patients with asymptomatic CAD, who were undergoing lipid-lowering therapy and underwent VH-IVUS evaluation for angiographically mild to moderate lesions, were enrolled in the study. Standard VH-IVUS parameters, including the percentage volume of the necrotic core (%NC) within the plaque and the presence of a virtual histology thin-cap fibroatheroma (VH-TCFA), were then evaluated. Additionally, monocyte subsets were assessed by flow cytometry, and daily glucose fluctuations were analyzed by measuring the mean amplitude of glycemic excursion (MAGE). RESULTS: Among 82 plaques from 22 diabetes mellitus (DM) patients and 29 non-DM patients, 15 VH-TCFAs were identified. CD14++CD16+ monocyte counts significantly correlated with both  %NC and the presence of VH-TCFA (%NC: r = 0.339, p = 0.002; VH-TCFA: p = 0.003). Multivariate logistic regression analysis revealed that CD14++CD16+ monocyte counts were independently associated with VH-TCFA (odds ratio = 1.029, p = 0.004). Furthermore, CD14++CD16+ monocyte counts were significantly correlated with the MAGE score in the non-DM patients (r = 0.544, p = 0.005). CONCLUSIONS: CD14++CD16+ monocyte levels are associated with coronary plaque vulnerability and can serve as a biomarker for VH-TCFA in patients with CAD undergoing lipid-lowering therapy. In patients without DM, glucose fluctuations may alter the balance of monocyte subsets. Trial registration UMIN Registry number: UMIN000021228.

Overexpression of Cytotoxic T-Lymphocyte-Associated Antigen-4 Prevents Atherosclerosis in Mice.

OBJECTIVE: Although T-cell-mediated chronic inflammation contributes to atherosclerosis development, the role of a negative regulatory molecule cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) in atherosclerosis is poorly understood. We investigated the effects of CTLA-4 overexpression on atherosclerosis in apolipoprotein E-deficient (Apoe(-/-)) mice. APPROACH AND RESULTS: We generated CTLA-4 transgenic (CTLA-4-Tg)/Apoe(-/-) mice that display constitutive cell surface and intracellular expression of CTLA-4 in T cells and assessed atherosclerosis at age 16 weeks. CTLA-4 overexpression significantly reduced atherosclerotic lesion formation and intraplaque accumulation of macrophage and CD4(+) T cells in the aortic root compared with controls. CTLA-4-Tg/Apoe(-/-) mice showed decreased numbers of effector CD4(+) T cells and decreased expression of costimulatory molecules CD80 and CD86, ligands for CTLA-4, and a costimulatory molecule CD28, on CD11c(+) dendritic cells compared with controls. Consistent with in vivo findings, in vitro experiments revealed that CD4(+) T cells from CTLA-4-Tg/Apoe(-/-) mice showed decreased proliferative capacity and proinflammatory cytokine production, downregulated CD80 expression on CD11c(+) dendritic cells, and suppressed the proliferation of other T cells by limiting the costimulatory pathway. Moreover, CD11c(+) dendritic cells from CTLA-4-Tg/Apoe(-/-) mice showed reduced proliferative activity of T cells in vitro, suggesting the suppression of dendritic cell maturation in vivo. CONCLUSIONS: CTLA-4 regulates atherosclerosis by suppressing proatherogenic immune responses and could be an attractive therapeutic target for atherosclerosis.

Circulating intermediate CD14++CD16+monocytes are increased in patients with atrial fibrillation and reflect the functional remodelling of the left atrium.

AIMS: A recent large clinical study demonstrated the association between intermediate CD14++CD16+monocytes and cardiovascular events. However, whether that monocyte subset contributes to the pathogenesis of atrial fibrillation (AF) has not been clarified. We compared the circulating monocyte subsets in AF patients and healthy people, and investigated the possible role of intermediate CD14++CD16+monocytes in the pathophysiology of AF. METHODS AND RESULTS: This case-control study included 44 consecutive AF patients without systemic diseases referred for catheter ablation at our hospital, and 40 healthy controls. Patients with systemic diseases, including structural heart disease, hepatic or renal dysfunction, collagen disease, malignancy, and inflammation were excluded. Monocyte subset analyses were performed (three distinct human monocyte subsets: classical CD14++CD16-, intermediate CD14++CD16+, and non-classical CD14+CD16++monocytes). We compared the monocyte subsets and evaluated the correlation with other clinical findings. A total of 60 participants (30 AF patients and 30 controls as an age-matched group) were included after excluding 14 AF patients due to inflammation. Atrial fibrillation patients had a higher proportion of circulating intermediate CD14++CD16+monocytes than the controls (17.0 ± 9.6 vs. 7.5 ± 4.1%, P < 0.001). A multivariable logistic regression analysis demonstrated that only the proportion of intermediate CD14++CD16+monocytes (odds ratio: 1.316; 95% confidence interval: 1.095-1.582, P = 0.003) was independently associated with the presence of AF. Intermediate CD14++CD16+monocytes were negatively correlated with the left atrial appendage flow during sinus rhythm (r= -0.679, P = 0.003) and positively with the brain natriuretic peptide (r = 0.439, P = 0.015). CONCLUSION: Intermediate CD14++CD16+monocytes might be closely related to the pathogenesis of AF and reflect functional remodelling of the left atrium.

Oral administration of the lactic acid bacterium Pediococcus acidilactici attenuates atherosclerosis in mice by inducing tolerogenic dendritic cells.

The intestinal microbiota appears to play an important role in the development of atherosclerosis. We investigated the effect of the probiotic lactic acid bacterium Pediococcus acidilactici R037 on atherosclerosis using apolipoprotein E-deficient (ApoE -/-) mice. Six-week-old ApoE -/- mice were orally administered R037 six times a week. Mice treated with R037 for 12 weeks exhibited markedly attenuated atherosclerotic lesions in the aortic root (2.3 ± 0.15 × 105 µm2 vs. 3.3 ± 0.29 × 105 µm2, respectively; P < 0.01; n = 15-17 each group). The expression of Ki-67 in CD4+ T cells, the population of interferon γ-producing CD4+ T cells in the spleen, and pro-inflammatory cytokine production from splenic lymphocytes were significantly decreased in R037-treated mice. Interestingly, splenic dendritic cells (DCs) isolated from R037-treated mice suppressed CD4+ T-cell proliferation and pro-inflammatory cytokine production ex vivo, suggesting that R037 treatment induced tolerogenic DCs. Programmed cell death ligand 1 expression in DCs was significantly enhanced in R037-treated mice, which might explain the immunosuppressive effect of DCs at least in part. These results indicate that R037 attenuates atherosclerosis by inducing tolerogenic DCs, which suppress Th1-driven inflammation and the proliferative activity of CD4+ T cells. Our findings may provide a novel therapeutic approach for the prevention of atherosclerosis based on dietary supplementation with probiotics.

Characterization of gut microbiota profiles in coronary artery disease patients using data mining analysis of terminal restriction fragment length polymorphism: gut microbiota could be a diagnostic marker of coronary artery disease.

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.

Gut Microbiota and Coronary Artery Disease.

Gut microbiota have been attracting increased attention in many fields of medicine recently. We can perform a comprehensive analysis of gut microbiota using next-generation sequencing techniques together with bioinformatics technology, which expands our knowledge of a large ecosystem consisting of a host and gut microbiota. We summarize some reports about the correlations between gut microbiota and metabolic disorders, particularly atherosclerosis, and discuss future directions for the diagnostic or therapeutic potential of gut microbiota. To take simple examples, we demonstrated that the order Lactobacillales was significantly increased; while the phylum Bacteroidetes was significantly decreased in coronary artery disease (CAD) patients compared with controls or healthy volunteers. The characteristics of gut microbiota in type 2 diabetes and dyslipidemia have been reported. However, these studies have limitations, and the biological significance of gut microbiota and the causal relationships are still controversial. We hope the reports listed in this review article might lead to the development of a novel therapy to prevent CAD via modulating gut microbiota or their metabolites.

Intestinal Immunity and Gut Microbiota as Therapeutic Targets for Preventing Atherosclerotic Cardiovascular Diseases.

Atherosclerosis is considered a chronic inflammatory disease and an intervention targeting the inflammatory process could be a new therapeutic strategy for preventing atherosclerotic cardiovascular diseases (CVD). We hypothesized that the intestine, which is considered the biggest immune organ in the human body, could be a therapeutic target for preventing CVD. We demonstrated that oral administration of anti-CD3 antibody or an active form of vitamin D3 reduced atherosclerosis in mice via induction of regulatory T cells and tolerogenic dendritic cells in the gut-associated lymphoid tissues. Similar to regulatory immune responses achieved by oral tolerance, our method had systemic effects that ultimately contributed towards atherosclerosis reduction. Recently, we have been interested in the gut microbiota, which have been reported as highly associated with intestinal immunity and systemic metabolic disorders, including obesity and diabetes. Notably, the guts of obese individuals are predominantly colonized by Firmicutes over Bacteroidetes. The association between atherosclerosis and microbiota has been attracting increased attention, and gut microbiota have been shown to participate in the metabolism of a proatherogenic compound called trimethylamine-N-oxide (TMAO) and aggravate CVD. Our investigation of the relationship between susceptibility to CVD and the gut microbiota revealed a characteristic flora type. Here, we discuss the evidence for the relationship between the gut microbiota and cardiometabolic diseases, and consider the gut microbiota as new potential therapeutic targets for treating CVD. (Circ J 2015; 79: 1882-1890).

Regulatory/effector T-cell ratio is reduced in coronary artery disease.

BACKGROUND: The protective function of regulatory T cells (Treg) has been identified in experimental atherosclerosis, but the contribution of Treg to the pathogenesis of human coronary artery disease (CAD) remains poorly understood. We investigated Treg and regulatory T-cell/effector T-cell (Treg/Teff) ratio in peripheral blood samples from CAD patients using a new strategy for precise identification of Treg. METHODS AND RESULTS: Peripheral blood samples were collected from 73 stable CAD patients (55 middle-aged CAD patients and 18 old CAD patients) and 64 controls (47 middle-aged controls and 17 young controls). CD3(+)CD4(+)FoxP3(+)T cells were divided into 3 fractions: CD45RA(+)FoxP3(low)resting Treg(Fr1), CD45RA(-)FoxP3(high)activated Treg(Fr2), and CD45RA(-)FoxP3(low)non-Treg(Fr3). CAD patients had lower percentages of Fr1 and Fr2 and higher percentages of Fr3 and CD45RA(-)Foxp3(-)Teff(Fr4+5) within the CD3(+)CD4(+)T-cell population compared to age-matched controls. Treg/Teff ratio (Fr1+2/Fr3+4+5) in CAD patients was also markedly lower than in controls (middle-aged control, 0.17±0.09 vs. middle-aged CAD, 0.10±0.05; P<0.001). The percentage of CD4(+)CD28(null)T cells within the CD4(+)T-cell population was negatively correlated with Treg/Teff ratio, excluding CD4(+)CD28(null)T cells <0.3% (r=-0.27, P<0.05). High-sensitivity C-reactive protein was also negatively correlated with Treg/Teff ratio (r=-0.22, P<0.05). CONCLUSIONS: CAD patients had reduced Treg and Treg/Teff ratio compared to healthy controls. The present findings may be helpful when developing immunotherapy for the prevention of CAD.

Intense impact of IL-1ß expressing inflammatory macrophages in acute aortic dissection.

There is no treatment for acute aortic dissection (AAD) targeting inflammatory cells. We aimed to identify the new therapeutic targets associated with inflammatory cells. We characterized the specific distribution of myeloid cells of both human type A AAD samples and a murine AAD model generated using angiotensin II (ANGII) and ß-aminopropionitrile (BAPN) by single-cell RNA sequencing (scRNA-seq). We also examined the effect of an anti-interleukin-1ß (IL-1ß) antibody in the murine AAD model. IL1B+ inflammatory macrophages and classical monocytes were increased in human AAD samples. Trajectory analysis demonstrated that IL1B+ inflammatory macrophages differentiated from S100A8/9/12+ classical monocytes uniquely observed in the aorta of AAD. We found increased infiltration of neutrophils and monocytes with the expression of inflammatory cytokines in the aorta and accumulation of inflammatory macrophages before the onset of macroscopic AAD in the murine AAD model. In blocking experiments using an anti-IL-1ß antibody, it improved survival of murine AAD model by preventing elastin degradation. We observed the accumulation of inflammatory macrophages expressing IL-1ß in both human AAD samples and in a murine AAD model. Anti-IL-1ß antibody could improve the mortality rate in mice, suggesting that it may be a treatment option for AAD.

Acute Coronary Syndrome Due to Intraplaque Hemorrhage in a Post-gastrectomy Patient with a Latent Severe Glycemic Disorder.

Glycemic disorders involving large glucose fluctuations and recurrent hypoglycemia may lead to adverse cardiovascular events, including acute coronary syndrome (ACS). Flash glucose monitoring (FGM) has reportedly been useful for detecting latent glycemic disorders. However, only a few studies have so far reported latent glycemic disorders in coronary artery disease. Thus, we herein present a unique case of ACS due to intraplaque hemorrhage in a post-gastrectomy patient who had no apparent coronary risk, except for a latent severe glycemic disorder detected via FGM. This masked etiology should be considered in ACS patients who have no apparent cardiovascular risks in order to improve their cardiovascular outcomes.

Histopathological findings of late-phase restenosis after directional coronary atherectomy with drug-coated balloon angioplasty: a case report.

Background: Drug-coated balloon angioplasty after directional coronary atherectomy (DCA) allows for a stentless strategy providing good short-term outcomes; however, late-phase restenosis and its mechanism remain unclear. Moreover, histopathological evaluation for late-phase restenosis post-drug-coated balloon angioplasty after DCA has never been reported. Case summary: We report the first case of late-phase restenosis post-drug-coated balloon angioplasty after DCA, wherein tissue analysis using intravascular coronary imaging and histopathology suggested neovascularization in newly developed neointimal proliferation. A 52-year-old man with a history of dyslipidaemia presented with exertional angina pectoris. He underwent percutaneous coronary intervention (PCI) with drug-coated balloon angioplasty after DCA for the proximal left anterior descending artery. Although coronary angiography after nine months revealed no restenosis, he experienced recurrent chest discomfort after 25 months. Coronary angiography confirmed late-phase restenosis, and intravascular ultrasound showed progressively developed neointima above the underlying residual plaque. Optical coherence tomography suggested developing neovascularization within the neointima. Stentless PCI with drug-coated balloon angioplasty after DCA was re-performed, and collected restenotic sample. The histopathological evaluation confirmed less-cellular neointimal proliferation with rich neovascularization and concomitant diffuse vascular endothelial growth factor (VEGF) expression. Discussion: Late-phase restenosis post-drug-coated balloon angioplasty after DCA comprised less-cellular neointima, suggesting inhibition of cell proliferation by drug-coated balloon efficacy. However, diffuse VEGF expression and concomitant rich neovascularization with haemorrhage and inflammation might indicate neointimal proliferation. Further large-scale investigations of the restenotic mechanism should be performed to avoid long-term target vascular failure after drug-coated balloon angioplasty post-DCA.

Gut Microbiota Influence the Development of Abdominal Aortic Aneurysm by Suppressing Macrophage Accumulation in Mice.

BACKGROUND: Abdominal aortic aneurysm (AAA) is a life-threatening cardiovascular disease characterized by dilated abdominal aorta. Immune cells have been shown to contribute to the development of AAA, and that the gut microbiota is associated with numerous diseases, including cardiovascular diseases, by regulating immune systems or metabolic pathways of the host. However, the interaction between the gut microbiota and AAA remains unknown. METHODS: Apolipoprotein E-deficient male mice were fed a high-cholesterol diet and divided into three groups: the control group was maintained under normal water (control group), the oral AVNM group was maintained under drinking water supplemented with ampicillin, vancomycin, neomycin, and metronidazole, and the i.p. AVNM group was injected AVNM intraperitoneally. After 1 week of pretreatment with antibiotics, these mice were administrated Ang II via subcutaneous osmotic pumps for 4 weeks and euthanized to evaluate AAA formation. RESULTS: Depletion of gut microbiota by oral AVNM ameliorated the incidence of AAAs (control group: 58.9% versus oral AVNM group: 28.6% versus i.p. AVNM group: 75.0%, P = 0.0005) and prevented death due to ruptured aneurysms (control group: 11% versus oral AVNM group: 0% versus i.p. AVNM group: 15%). Oral AVNM suppressed monocyte storage in the spleen, but not in other organs. Despite possessing a higher level of cholesterol, recruitment of monocytes into the suprarenal aorta was suppressed in the oral AVNM group. In AVNM drinking mice, NOD1 ligand, a kind of PRR ligands, increased the development of AAAs and accumulation of macrophages in the aortae. CONCLUSIONS: The gut microbiota plays a critical role in AAA formation. Therefore, regulation of the microbiota or the immune system can be a therapeutic approach for AAA.