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Background/Aims: Newly identified IL-10-producing regulatory B cells (Bregs) have been shown to play an important role in the suppression of immune responses. Chronic immune activation participates in the pathogenesis of dilated cardiomyopathy (DCM) but whether Bregs are involved in its development remains unclear. We aimed to investigate the circulating frequency and function of Bregs in DCM. Methods: In total, 35 DCM patients (20 men and 15 women) and 44 healthy controls (23 men and 21 women) were included in the experiment, and the frequency of Bregs was detected using flow cytometry. Results: According to our results, the frequency of circulating IL-10-producing Bregs was significantly lower in DCM patients compared with healthy controls. Furthermore, the CD24hiCD27+ B cell subset in which IL-10-producing Bregs were mainly enriched from DCM patients showed impaired IL-10 expression and a decreased ability to suppress the TNF-α production of CD4+CD25- Tconv cells and to maintain Tregs differentiation. Correlation analysis showed that the frequency of IL-10-producing Bregs and the suppressive function of CD24hiCD27+ B cells were positively correlated with left ventricular ejection fraction and negatively correlated with NT-proBNP in DCM patients. Conclusions: In conclusion, the reduced frequency and impaired functions suggest a potential role of Bregs in the development of DCM.

Background/Aims: Recent studies have shown that circulating microRNAs (miRNAs) are emerging as promising biomarkers for cardiovascular diseases. This study aimed to determine whether miR-19b-3p, miR-134-5p and miR-186-5p can be used as novel indicators for acute myocardial infarction (AMI). Methods: To investigate the kinetic expression of the three selected miRNAs, we enrolled 18 patients with AMI and 20 matched controls. Plasma samples were collected from each participant, and total RNA was extracted. Quantitative real-time PCR and ELISA assays were used to investigate the expression of circulating miRNAs and cardiac troponin I (cTnI), respectively. Plasma samples from another age- and gender-matched cohort were collected to investigate the impact of medications for AMI on the expression of the selected miRNAs. Results: Levels of plasma miR-19b-3p, miR-134-5p and miR-186-5p were significantly increased in early stage of AMI. Plasma miR-19b-3p and miR-134-5p levels reached peak expression immediately after admission (T0), whereas miR-186-5p achieved peak expression at 4 h after T0. All of these times were earlier than the peak for cTnI (8 h after T0). In addition, all three miRNAs were positively correlated with cTnI. Receiver Operating Characteristic (ROC) analysis indicated that each single miRNA showed considerable diagnostic efficiency for predicting AMI. Furthermore, combining all three miRNAs in a panel increased the efficiency of distinguishing between patients with AMI and controls. Moreover, we found that heparin and medications for AMI did not impact the expression of these circulating miRNAs. Conclusion: Circulating miR-19b-3p, miR-134-5p and miR-186-5p could be considered promising novel diagnostic biomarkers for the early phase of AMI.

Background: Interleukin (IL)-17A, a newly identified cytokine, may participate in the transition of a stable plaque into an unstable plaque. Macrophages play a critical role in the destabilization of atherosclerotic plaque. Methods: RAW 264.7 cells were stimulated with IL-17A. The mRNA expression of inflammatory cytokines was determined by RT-PCR. The cytokines production in the supernatants was measured by ELISA. Small interfering RNA (siRNA) was used to confirm that IL-17A-induced pro-inflammatory cytokines production via IL-17RA signaling. The western blot assay was used to detect the phosphorylation of MAPKinases including p38 and ERK1/2. The DNA binding activity of nuclear factor NF-κB and AP-1 were detected by EMSA. Results: IL-17A induced the production of pro-inflammatory cytokines in macrophages in a time- and dose-dependent manner, such as tumor necrosis factor (TNF)-a, IL-1ß, and IL-6. Meanwhile, IL-17A resulted in the phosphorylation of p38 and ERK1/2 and increased DNA-binding activity of NF-κB and AP-1. Pharmacological inhibitors of p38 and ERK1/2 partly attenuated IL-17A-induced TNF-a, IL-1ß, and IL-6 production. Either NF-κB inhibitor or AP-1 inhibitor also partly decreased the IL-17A-induced cytokine production. Conclusions: IL-17A induces pro-inflammatory cytokines production in macrophages via MAPKinases, NF-κB and AP-1 pathway.