Diagnostic and prognostic value of plasma miR-106a-5p levels in patients with acute heart failure.

BACKGROUND: It is essential to find reliable biomarkers for early diagnosis and prognosis of acute heart failure (AHF) for its mitigation. Currently, increasing attention is paid to the role of microRNAs (miRNAs/miRs) as diagnostic or prognostic markers for cardiovascular diseases. Since plasma miR-106a-5p has been observed to be downregulated in AHF, its value in the diagnosis and prognostic assessment of AHF deserves further exploration. Accordingly, this study analyzed the diagnostic and prognostic value of plasma miR-106a-5p in AHF patients. METHODS: Prospectively, this study included 127 AHF patients who met the 2021 European Society of Cardiology Guidelines and 127 control individuals. Plasma miR-106a-5p levels were determined with RT-qPCR. Spearman correlation analysis was performed to evaluate the correlation of plasma miR-106a-5p levels with NT-proBNP and hs-CRP levels in AHF patients. All AHF patients were followed up for 1 year and allocated into poor and good prognosis groups, and plasma miR-106a-5p levels were compared. The diagnostic and prognostic value of plasma miR-106a-5p for AHF was assessed with a receiver-operating characteristic curve. RESULTS: Plasma miR-106a-5p was lowly expressed in AHF patients versus controls (0.53 ± 0.26 vs. 1.09 ± 0.46) and showed significant negative correlations with NT-proBNP and hs-CRP levels. Plasma miR-106a-5p level < 0.655 could assist in AHF diagnosis. Plasma miR-106a-5p levels were markedly lower in poor-prognosis AHF patients than in good-prognosis patients. Plasma miR-106a-5p level < 0.544 could assist in predicting poor prognosis in AHF patients. CONCLUSION: Plasma miR-106a-5p is downregulated in AHF patients and could assist in diagnosis and poor prognosis prediction of AHF.

CircMACF1 alleviates myocardial fibrosis after acute myocardial infarction by suppressing cardiac fibroblast activation via the miR-16-5p/SMAD7 axis.

Circular RNAs (circRNAs) played a pivotal role in myocardial fibrosis after acute myocardial infarction (AMI). The activation of cardiac fibroblasts (CFs) and accumulation of extracellular matrix are the main characteristics of myocardial fibrosis. In our research, we aimed to elucidate the functional roles of circMACF1 in CF activation after AMI as well as the underlying mechanism. Human CFs were activated by TGF-ß1 treatment. qPCR and western blotting were performed to investigate gene and protein expression. CCK-8 and transwell assays were carried out to measure cell proliferation, and migration. Immunofluorescence was used to investigate α-SMA level. The interaction between miR-16-5p and circMACF1 or SMAD7 was revealed by RIP or dual luciferase reporter gene assays. CircMACF1 and SMAD7 were repressed in AMI patients and CFs treated with TGF-ß1, and miR-16-5p was increased. In addition, circMACF1 was resistant to RNase R and abundantly expressed in the cytoplasm. Overexpression of circMACF1 inhibited cell proliferation and migration and reduced the expression levels of fibrosis-related proteins, including Collagen I, Collagen III, and α-SMA. Furthermore, circMCAF1 could directly bind to miR-16-5p, and SMAD7 was a target gene of miR-16-5p. Knockdown of miR-16-5p suppressed the activation, proliferation, and migration of TGF-ß1-treated CFs, but silencing circMACF1 or SMAD7 partially reversed this phenomenon. CircMACF1 attenuated the TGF-ß1-induced activation, proliferation and migration of CFs via the miR-16-5p/SMAD7 signaling pathway, indicating that circMACF1 might be a new therapeutic target for AMI.

LncRNA XIST facilitates hypoxia-induced myocardial cell injury through targeting miR-191-5p/TRAF3 axis.

Myocardial infarction is one of the most lethal diseases in cardiovascular diseases. In the present work, we aimed to elucidate the molecular and functional association long non-coding RNA (lncRNA) X-inactive specific transcript (XIST), microRNA (miR)-191-5p, and TNF receptor-associated factor 3 (TRAF3). Human cardiomyocyte primary cells (HCMs) were stimulated by hypoxia to establish a model of myocardial injury in vitro. The relative expressions of XIST, miR-191-5p, and TRAF3 were measured using quantitative real-time polymerase chain reaction (qRT-PCR) assay. The capabilities of proliferation and apoptosis were determined using cell counting kit (CCK-8) and flow cytometry assays, respectively. The molecular interactions were verified using dual luciferase assay. The protein contents of TRAF3, Bcl-2, and Bax were calculated using western blot assay. XIST was significantly increased, but miR-191-5p was reduced in hypoxia-treated HCMs compared to that in control group. Either downregulated XIST or enforced miR-191-5p markedly enhanced cell viability and restrained cell apoptotic rate in hypoxia-treated HCMs. Mechanistically, XIST directly interacted with miR-191-5p to competitive releasing TRAF3 expression. Importantly, overexpression of TRAF3 dramatically diminished the protective effects of XIST knockdown on hypoxia-triggered HCMs injury. Collectively, our data elucidated a novel "lncRNA XIST/miR-191-5p/TRAF3" molecular network in vitro, indicating that the reduced lncRNA XIST-protected HCMs from hypoxia-induced cell injury by regulating miR-191-5p/TRAF3 signaling, which might provide some convincing evidences for further understanding the influences of "lncRNA-miRNA-mRNA" network in the development of MI.