BCAA-nitrogen flux in brown fat controls metabolic health independent of thermogenesis.

Brown adipose tissue (BAT) is best known for thermogenesis. Rodent studies demonstrated that enhanced BAT thermogenesis is tightly associated with increased energy expenditure, reduced body weight, and improved glucose homeostasis. However, human BAT is protective against type 2 diabetes, independent of body weight. The mechanism underlying this dissociation remains unclear. Here, we report that impaired mitochondrial catabolism of branched-chain amino acids (BCAAs) in BAT, by deleting mitochondrial BCAA carriers (MBCs), caused systemic insulin resistance without affecting energy expenditure and body weight. Brown adipocytes catabolized BCAA in the mitochondria as nitrogen donors for the biosynthesis of non-essential amino acids and glutathione. Impaired mitochondrial BCAA-nitrogen flux in BAT resulted in increased oxidative stress, decreased hepatic insulin signaling, and decreased circulating BCAA-derived metabolites. A high-fat diet attenuated BCAA-nitrogen flux and metabolite synthesis in BAT, whereas cold-activated BAT enhanced the synthesis. This work uncovers a metabolite-mediated pathway through which BAT controls metabolic health beyond thermogenesis.

Optimizing High-Resolution MR Angiography: The Synergistic Effects of 3D Wheel Sampling and Deep Learning-Based Reconstruction.

OBJECTIVE: The aim of this study was to assess the utility of the combined use of 3D wheel sampling and deep learning-based reconstruction (DLR) for intracranial high-resolution (HR)-time-of-flight (TOF)-magnetic resonance angiography (MRA) at 3 T. METHODS: This prospective study enrolled 20 patients who underwent head MRI at 3 T, including TOF-MRA. We used 3D wheel sampling called "fast 3D" and DLR for HR-TOF-MRA (spatial resolution, 0.39 × 0.59 × 0.5 mm3) in addition to conventional MRA (spatial resolution, 0.39 × 0.89 × 1 mm3). We compared contrast and contrast-to-noise ratio between the blood vessels (basilar artery and anterior cerebral artery) and brain parenchyma, full width at half maximum in the P3 segment of the posterior cerebral artery among 3 protocols. Two board-certified radiologists evaluated noise, contrast, sharpness, artifact, and overall image quality of 3 protocols. RESULTS: The contrast and contrast-to-noise ratio of fast 3D-HR-MRA with DLR are comparable or higher than those of conventional MRA and fast 3D-HR-MRA without DLR. The full width at half maximum was significantly lower in fast 3D-MRA with and without DLR than in conventional MRA (P = 0.006, P < 0.001). In qualitative evaluation, fast 3D-MRA with DLR had significantly higher sharpness and overall image quality than conventional MRA and fast 3D-MRA without DLR (sharpness: P = 0.021, P = 0.001; overall image quality: P = 0.029, P < 0.001). CONCLUSIONS: The combination of 3D wheel sampling and DLR can improve visualization of arteries in intracranial TOF-MRA.

Dysregulation of Amphiregulin stimulates the pathogenesis of cystic lymphangioma.

Along with blood vessels, lymphatic vessels play an important role in the circulation of body fluid and recruitment of immune cells. Postnatal lymphangiogenesis commonly occurs from preexisting lymphatic vessels by sprouting, which is induced by lymphangiogenic factors such as vascular endothelial growth factor C (VEGF-C). However, the key signals and cell types that stimulate pathological lymphangiogenesis, such as human cystic lymphangioma, are less well known. Here, we found that mouse dermal fibroblasts that infiltrate to sponges subcutaneously implanted express VEGF-D and sushi, Von Willebrand factor type A, EGF, and pentraxin domain containing 1 (SVEP1) in response to PDGFRß signal. In vitro, Pdgfrb knockout (ß-KO) fibroblasts had reduced expression of VEGF-D and SVEP1 and overproduced Amphiregulin. Dysregulation of these three factors was involved in the cyst-like and uneven distribution of lymphatic vessels observed in the ß-KO mice. Similarly, in human cystic lymphangioma, which is one of the intractable diseases and mostly occurs in childhood, fibroblasts surrounding cystic lymphatics highly expressed Amphiregulin. Moreover, fibroblast-derived Amphiregulin could induce the expression of Amphiregulin in lymphatic endothelial cells. The dual source of Amphiregulin activated EGFR expressed on the lymphatic endothelial cells. This exacerbation cascade induced proliferation of lymphatic endothelial cells to form cystic lymphangioma. Ultimately, excessive Amphiregulin produced by fibroblasts surrounding lymphatics and by lymphatic endothelial cells per se results in pathogenesis of cystic lymphangioma and will be a fascinating therapeutic target of cystic lymphangioma.

Trends of disease activity in Japanese patients over 75 years with rheumatoid arthritis from 2014 to 2021- the ANSWER cohort study.

OBJECTIVES: To investigate if disease activity among elderly RA patients over 75 years has changed over time in the real-world clinical setting. METHODS: Data from an observational multicentre registry of RA patients in Japan were analyzed. The primary outcome was to evaluate the changes in the proportion of very elderly RA patients (over 75 years) who achieved remission and low disease activity, from 2014 to 2021. The secondary outcome was to identify factors associated with remission and low disease activity by comparing demographic and clinical characteristics among the patients who had a study visit within the study period, using multivariate logistic regression. RESULTS: A total of 32 161 patient visits were identified from 2014 to 2021. The proportion of patients over 75 years increased from 16.5% to 26.9%, with biologics and targeted-synthetic disease modifying anti-rheumatic drugs (b/tsDMARDs) usage increasing and glucocorticoids usage decreasing, while conventional-synthetic DMARDs usage remained relatively stable. The proportion of RA patients over 75 years achieving remission and low disease activity significantly increased from 62.2% to 78.2% (p for trend < 0.001). A negative factor associated with achieving remission and low disease activity was glucocorticoid usage, seropositivity, and history of previous b/tsDMARDs use while MTX usage was associated positively, independent of other predictors. CONCLUSIONS: In our cohort, disease activity among very elderly RA patients has improved over time. The study suggests the importance of using a treat-to-target approach in very elderly RA patients to improve clinical outcomes.

Real-world comparative study of the efficacy of Janus kinase inhibitors in patients with rheumatoid arthritis: the ANSWER cohort study.

OBJECTIVE: This multicentre, retrospective study compared the efficacy and safety of tofacitinib, baricitinib, peficitinib and upadacitinib in real-world clinical settings after minimizing selection bias and adjusting the confounding patient characteristics. METHOD: The 622 patients were selected from the ANSWER cohort database and treated with tofacitinib (TOF), baricitinib (BAR), peficitinib (PEF) or upadacitinib (UPA). The patient's background was matched using propensity score-based inverse probability of treatment weighting (IPTW) among four treatment groups. The values of Clinical Disease Activity Index (CDAI), C-reactive protein (CRP), and modified Health Assessment Questionnaire (mHAQ) after drug initiation and the remission or low disease activity (LDA) rates of CDAI at 6 months after drug initiation were compared among the four groups. Further, the predictive factor for TOF and BAR efficacy was analysed. RESULTS: The retention and discontinuation rates until 6 months after drug initiations were not significantly different among the four JAK inhibitors treatment groups. Mean CDAI value, CDAI remission rate, and CDAI-LDA rate at 6 months after drug initiation were not significantly different among treatment groups. Baseline CDAI (TOFA: OR 1.09, P < 0.001; BARI: OR 1.07, P < 0.001), baseline CRP (TOFA: OR 1.32, P = 0.049), baseline glucocorticoid dose (BARI: OR 1.18, 95% CI 1.01-1.38, P = 0.035), a number of previous biological or targeted synthetic disease-modifying antirheumatic drugs (biological/targeted synthetic DMARDs) (BARI: OR 1.36, P = 0.004) were predictive factors for resistance to CDAI-LDA achievement to JAK inhibitor treatment. CONCLUSION: The efficacy and safety of TOF, BAR, PEF and UPA were not significantly different for the treatment of patients with rheumatoid arthritis.

Does selection occur at the intermediate zone of two insufficiently isolated populations? A whole-genome analysis along an altitudinal gradient.

Adaptive divergence occurs even between insufficiently isolated populations when there is a great difference in environments between their habitats. Individuals present in an intermediate zone of the two divergent populations are expected to have an admixed genetic structure due to gene flow. A selective pressure that acts on the genetically admixed individuals may limit the gene flow and maintain the adaptive divergence. Here, we addressed a question whether selection occurs in the genetically admixed individuals between two divergent populations. Arabidopsis halleri is a perennial montane plant, which has clear phenotypic dimorphisms between highland and lowland habitats in Mt. Ibuki, central Japan. We obtained the whole-genome sequences of Arabidopsis halleri plants along an altitudinal gradient of 359-1,317 m with a high spatial resolution (mean altitudinal interval of 20 m). We found a zone where the highland and lowland genes were mixing (intermediate subpopulation). In the intermediate subpopulation, we identified 5 and 13 genome regions, which included 3 and 8 genes, that had a high frequency of alleles that are accumulated in highland and lowland subpopulations, respectively. In addition, we also found that the frequency of highland alleles of these selected genome regions was smaller in the lowland subpopulation compared with that of the non-selected regions. These results suggest that the selection in the intermediate subpopulation might limit the gene flow and contribute to the adaptive divergence between altitudes. We also identified 7 genome regions that had low heterozygote frequencies in the intermediate subpopulation. We conclude that different types of selection in addition to gene flow occur at the intermediate altitude and shape the genetic structure across altitudes.

Evaluating of the Quality of Hepatic Diffusion Weighted Imaging Using Multiband Imaging With Variable-Rate Selective Excitation.

OBJECTIVE: To assess the image quality of diffusion-weighted imaging (DWI) using multiband (MB) imaging with variable-rate selective excitation (VERSE) and compare it to conventional DWI. METHODS: We retrospectively evaluated hepatic DWI images of patients (n = 76) according to either the conventional method (SENSE, acceleration factor = 2) (n = 38) or fast scanning method (MB imaging with VERSE, acceleration factor = 2 × 2) (n = 38). We also conducted a volunteer study (n = 15) for those scanning methods. During quantitative analysis, the signal-to-noise ratio (SNR), apparent diffusion coefficient values, and contrast in the liver, spleen, and spinal cord were compared between the 2 groups. During qualitative analysis, all images were independently and blindly evaluated by 2 board-certified radiologists. The image contrast, noise, artifacts, and sharpness were assessed, and the performance of classification was measured using receiver operating characteristic curve analysis. RESULTS: In the retrospective study, the SNRs of the hepatic parenchyma and spinal cord between the 2 protocols were significantly different (liver, 8.9 [interquartile range {IQR}, 7.6-12.2] vs 13.0 [IQR, 10.0-16.7]; P < 0.001 and spinal cord, 6.0 [IQR, 4.7-9.4] vs 4.3 [IQR, 3.8-6.8]; P < 0.02). No significant differences between the 2 protocols in the other retrospective analyses were noted. In the receiver operating characteristic curve analysis, area under the curve was 0.49 (95% confidence intervals, 0.40-0.58). CONCLUSION: Multiband VERSE reduced scan time and SNR of hepatic DWI; however, subjective image quality parameters were not significantly impacted.

Spectral imaging with dual-layer spectral detector computed tomography for the detection of perfusion defects in acute coronary syndrome.

To evaluate the feasibility of spectral imaging with dual-layer spectral detector computed tomography (CT) for the diagnosis of acute coronary syndrome. We identified 30 consecutive patients who underwent cardiac CT using dual-layer spectral detector CT and were diagnosed with acute ischemic syndrome by an invasive coronary angiography. We reconstructed 120 kVp images and generated virtual monochromatic images (VMIs; 40-200 keV in 10 keV increments), iodine concentration maps, and effective atomic number (Z) maps. We calculated the contrast and contrast-to-noise ratio (CNR) between myocardial normal and hypo-perfusion and chose the VMIs with the best CNR for quantitative analysis. We compared the image noise, contrast, and CNR of 120 kVp images and the best VMIs, CT value, iodine concentration, and effective Z between myocardial normal and hypo-perfusion with the paired t test. As the X-ray energy decreased, venous attenuation, contrast, and CNR gradually increased. The 40 keV image yielded the best CNR. The contrast and CNR between myocardial normal and hypo-perfusion were significantly higher in 40 keV images than those in 120 kVp images. The iodine concentration and the effective Z were significantly higher in normal myocardium than those in hypo-perfused myocardium. Spectral imaging with dual-layer spectral detector CT is a feasible technique to detect the hypo-perfused area of acute ischemic syndrome.

Circulating intermediate monocytes and atrial structural remodeling associated with atrial fibrillation recurrence after catheter ablation.

BACKGROUND: Inflammation, such as that associated with intermediate CD14++ CD16+ monocytes and atrial structural remodeling (SRM), may be important in the recurrence of atrial fibrillation (AF) after catheter ablation. However, the relationship between the intermediate CD14++ CD16+ monocytes, SRM, and AF recurrence is unclear. METHODS: Twenty-four patients with AF were enrolled. The proportion of intermediate monocytes (PIM) was assessed before ablation by flow cytometry. As a surrogate marker of SRM, the volume ratio (VR) of signal intensity greater than 1 standard deviation on late-gadolinium enhancement magnetic resonance imaging (LGE-MRI) was calculated. We investigated whether PIM correlated with SRM on LGE-MRI and determined the optimal cutoff value for predicting AF recurrence. RESULTS: Univariate analysis revealed positive correlations between PIM and BNP with SRM (PIM: r = .593, p = .002; BNP: r = .567, p = .004). Multivariable analysis revealed that PIM was independently associated with VR on LGE-MRI (ß = .522; p = .033). The finding of an area under the receiver operating characteristic curve of 0.750 revealed that a VR ≥ 13.3% on LGE-MRI as the optimal cutoff value to predict AF recurrence with 80% sensitivity and 71% specificity, which was associated with PIM ≥ 10.0%. CONCLUSION: Intermediate monocytes were significantly positively correlated with SRM. PIM ≥ 10% was associated with a VR ≥ 13.3% on LGE-MRI, which predicted AF recurrence after catheter ablation.

Gut microbial composition in patients with atrial fibrillation: effects of diet and drugs.

Atrial fibrillation (AF) reduces the quality of life by triggering stroke and heart failure. The association between AF onset and gut metabolites suggests a causal relationship between AF and gut microbiota dysbiosis; however, the relationship remains poorly understood. We prospectively enrolled 34 hospitalized patients with AF and 66 age-, sex-, and comorbidity-matched control subjects without a history of AF. Gut microbial compositions were evaluated by amplicon sequencing targeting the 16S ribosomal RNA gene. We assessed differences in dietary habits by using a brief-type self-administered diet history questionnaire (BDHQ). Gut microbial richness was lower in AF patients, although the diversity of gut microbiota did not differ between the two groups. At the genus level, Enterobacter was depleted, while Parabacteroides, Lachnoclostridium, Streptococcus, and Alistipes were enriched in AF patients compared to control subjects. The BDHQ revealed that the intake of n-3 polyunsaturated fatty acids and eicosadienoic acid was higher in AF patients. Our results suggested that AF patients had altered gut microbial composition in connection with dietary habits.

Preoperative frailty affects postoperative complications, exercise capacity, and home discharge rates after surgical and transcatheter aortic valve replacement.

Assessment of frailty is important for risk stratification among the elderly with severe aortic stenosis (AS) when considering interventions such as surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR). However, evidence of the impact of preoperative frailty on short-term postoperative outcomes or functional recovery is limited. This retrospective study included 234 consecutive patients with severe AS who underwent SAVR or TAVR at Kobe University Hospital between Dec 2013 and Dec 2019. Primary outcomes were postoperative complications, postoperative 6-min walking distance (6MWD), and home discharge rates. The mean age was 82 ± 6.6 years. There were 169 (SAVR: 80, TAVR: 89) and 65 (SAVR: 20, TAVR: 45) patients in the non-frail and frail groups, respectively (p = 0.02). The postoperative complication rates in the frail group were significantly higher than those in the non-frail group [30.8% (SAVR: 35.0%, TAVR: 28.9%) vs. 10.7% (SAVR: 15.0%, TAVR: 6.7%), p < 0.001]. The home discharge rate in the non-frail group was significantly higher than that in the frail group [85.2% (SAVR: 81.2%, TAVR: 88.8%) vs. 49.2% (SAVR: 55.0%, TAVR: 46.7%), p < 0.001]. The postoperative 6MWD in the non-frail group was significantly longer than that in the frail group [299.3 ± 87.8 m (SAVR: 321.9 ± 90.8 m, TAVR: 281.1 ± 81.3 m) vs. 141.9 ± 92.4 m (SAVR: 167.8 ± 92.5 m, TAVR: 131.6 ± 91.3 m), p < 0.001]. The TAVR group did not show a decrease in the 6MWD after intervention, regardless of frailty. We report for the first time that preoperative frailty was strongly associated with postoperative complications, 6MWD, and home discharge rates following both SAVR and TAVR. Preoperative frailty assessment may provide useful indications for planning better individualized therapeutic interventions and supporting comprehensive intensive care before and after interventions.

Circulating intermediate monocytes and toll-like receptor 4 correlate with low-voltage zones in atrial fibrillation.

Inflammation has been suggested to play a key role in the pathogenesis of atrial fibrillation (AF). Our hypothesis was that this inflammation, mediated by intermediate monocytes and toll-like receptor 4 (TLR4), causes the formation and expansion of low-voltage zones (LVZs). Prior to ablation, the monocyte subsets of 78 AF patients and TLR4 expression of 66 AF patients were analyzed via a flow cytometric analysis. Based on the CD14/CD16 expression, the monocytes were divided into three subsets: classical, intermediate, and non-classical. At the beginning of the ablation session, voltage mapping was performed. LVZs were defined as all bipolar electrogram amplitudes of < 0.5 mV. Correlations between the flow cytometric analysis results and presence of LVZs, as well as the total area of the LVZ, were examined. Patients with LVZs clearly had a higher proportion of intermediate monocytes (10.0 ± 3.6% vs. 7.2 ± 2.7%, p < 0.001) than those without LVZs. TLR4 was much more frequently expressed in the intermediate monocytes than other two monocyte subsets (p < 0.001). Moreover, the TLR4 expression level in intermediate monocytes correlated positively with the total area of the LVZs (r = 0.267, p = 0.030), especially in patients with paroxysmal AF (r = 0.365, p = 0.015). The intermediate monocytes and TLR4 expression positively correlated with LVZs in AF patients.

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.

Plasticity of functional traits and optimality of biomass allocation in elevational ecotypes of Arabidopsis halleri grown at different soil nutrient availabilities.

In mountainous areas, plant distribution is constrained by various environmental stresses. Plasticity and constancy in plant functional traits may relate to optimal strategies at respective habitats and to ecotypic differentiation along elevation. Although plant biomass allocation has been extensively studied in relation to adaptation to soil nutrient availability along elevation, its optimality is still poorly understood. We examined soil nutrient availability in the field and conducted growth analysis for two elevational ecotypes of Arabidopsis halleri grown under different nutrient availabilities. We determined plasticity in morphological and physiological traits and evaluated optimal biomass allocation using an optimality model. Our field investigation indicated that soil nitrogen (N) availability increased rather than decreased with increasing elevation. Our growth analysis revealed that lowland ecotype was more plastic in morphological variables and N concentrations, whereas the highland ecotype was more plastic in other physiological variables such as the net assimilation rate (NAR). The leaf mass ratio (LMR) in the lowland ecotype was moderately plastic at the whole range of N availabilities, whereas LMR in the highland ecotype was very plastic at higher N availabilities only. The optimality model indicated that the LMR of the lowland ecotype was nearly optimal throughout the range of studied N availabilities, whereas that of the highland ecotype was suboptimal at low N availability. These results suggest that highland ecotype is adapted only to high N availability, whereas the lowland ecotype is adapted to a relatively wide range of N availabilities as a result of natural selection in their respective habitats. We conclude that an adaptive differentiation has occurred between the two ecotypes and plasticity in the biomass allocation is directly related to its optimization in changing environments.

Different PDGF Receptor Dimers Drive Distinct Migration Modes of the Mouse Skin Fibroblast.

BACKGROUND/AIMS: The migration of mesenchymal cells is a fundamental cellular process that has been implicated in many pathophysiological conditions and is induced by chemoattractants such as platelet-derived growth factors (PDGFs). However, the regulatory mechanisms shaping this migration remain to be elucidated. METHODS: Here, we prepared mouse skin fibroblasts inactivated for different PDGF receptor genes and systematically measured their chemotactic responses within a gradient of different chemoattractants. RESULTS: We found that PDGFRαß and PDGFRßß dimers were strong inducers of random and directionally-persistent migration, respectively, that was sustained for up to 24 h. MAPK and PI3K were necessary to mediate random and directional migration, respectively. Directional migration was accompanied by abundant ventral stress fiber formation and consistent cell shape with less frequent formation of branch-like processes. CONCLUSION: This is the first systematic study that characterized the chemotaxis mediated by three-different types of PDGFR dimers in mesenchymal cell migration. Our data demonstrate that PDGFR dimer formation is the critical step to determine the specific mode of fibroblast chemotaxis, while the accompanying cytoskeletal remodeling might contribute to migration persistence.

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.

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.

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.