miR‐499 released during myocardial infarction causes endothelial injury by targeting α7‐nAchR

Abstract

The surged systemic vascular inflammation after acute myocardial infarction (AMI) aggravates the atherosclerotic endothelial injury. To explore roles of miR‐499 released from cardiomyocytes during AMI in endothelial injury. Using qPCR and ELISA, we discovered that patients with AMI had significantly increased plasma miR‐499, which was directly correlated with serum thrombomodulin, a marker for endothelial injury. Plasma of AMI patients, when incubated with human umbilical vein endothelial cells (HUVECs), significantly increased the expression of endothelial injury markers, which could be abrogated by antagomiR‐499. In vitro, neonatal rat cardiomyocytes subjected to hypoxia/reoxygenation (HX/R) released miR‐499 that could be internalized into rat pulmonary microvascular endothelial cells (RPMECs), worsening the high glucose‐induced injury. In silico analysis demonstrated that CHRNA7 encoding α7‐nAchR is a target of miR‐499, which was validated in cell lines expressing endogenous α7‐nAchR. In high glucose‐induced RPMECs injury model, miR‐499 aggravated, whereas forced CHRNA7 expression ameliorated the injury. Moreover, the perfusate from Langendorff perfused rat heart subjected to HX/R contained higher level of miR‐499 that significantly impaired the Bradykinin‐mediated endothelium‐dependent relaxation in both conduit and resistance arteries, which could be partially abrogated by antagomiR‐499. Finally, the correlation between plasma miR‐499 and endothelial injury was further confirmed in another cohort of AMI patients. We conclude that miR‐499 released from injured cardiomyocytes contributes to the endothelial injury by targeting α7‐nAchR. This study implies that miR‐499 may serve as a potential target for the treatment of the surged vascular inflammation post‐AMI.

Myocardial Infarction-Associated Extracellular Vesicle-Delivered miR-208b Affects the Growth of Human Umbilical Vein Endothelial Cells via Regulating CDKN1A

“…Since miR-499 released during MI has been investigated [ 21 ], this study determined the expression levels of miR-208b, miR-122-5p, and miR-134 in the EVs isolated from the plasma of MI patients and healthy individuals. The results showed that miR-208b level in the MI-associated EVs was significantly higher than that in the normal exosomes, which indicated that miR-208b enrichment may be closely associated with the development of MI.…”

miR‑133a‑3p regulates the proliferation and apoptosis of intestinal epithelial cells by modulating the expression of TAGLN2

“…Abnormal expression of miR-146a and miR-223 have also been identified in the serum of patients with sepsis; these, along with miR-122 and miR-21, have been suggested as biomarkers for the diagnosis of sepsis (29,30). A previous study also confirmed that miR-499 serves a significant role in the diagnosis of myocardial injury in sepsis (31). A number of previous studies have also focused on miR-133a, and its role in cell differentiation, skeletal muscle proliferation, cancer development and fibrosis has been confirmed (32)(33)(34)(35)(36).…”

p53 Promotes Differentiation of Cardiomyocytes from hiPSC through Wnt Signaling-Mediated Mesendodermal Differentiation

“…All primers used were listed in Supplementary Table S1 . The expression of target gene was normalized to GAPDH and calculated using 2 −ΔΔCt method as described previously ( 18 ).…”

“…Western blot was performed following the protocol reported previously ( 18 ). Briefly, cells were lysed using RIPA lysis buffer supplemented with proteinase inhibitor cocktail (78430, Thermo Fisher Scientific, USA), sonicated and boiled for 10 min.…”