MicroRNA-223 Regulates Cardiac Fibrosis After Myocardial Infarction by Targeting RASA1

Abstract

Background/Aims: Percutaneous coronary intervention reduces acute myocardial infarction (MI)-induced mortality to a great extent, but effective treatments for MI-induced cardiac fibrosis and heart failure are still lacking. MicroRNAs (miRNAs) play a variety of roles in cells and have thus been investigated extensively. MicroRNA-223 (miR-223) expression has been reported to be altered in post-MI heart failure in humans; however, the roles of miR-223 in MI remain unknown. Our study aimed to elucidate the roles of miR-223 in cardiac fibrosis. Methods: Cultured cardiac fibroblasts (CFs) were activated by TGF-β1 stimulation. Gain and loss of miR-223 and RAS p21 protein activator 1 (RASA1) knockdown in CFs were achieved by transfecting the cells with miR-223 mimics and inhibitors, as well as small interfering RNA-RASA1 (siRASA1), respectively. Quantitative real-time reverse transcriptase-polymerase chain reactions (qRT-PCR) was used to determine miR-223-3p and RASA1 expression levels, and Cell Counting Kit-8 (CCK-8), transwell migration and scratch assays were performed to assess CFs viability and migration, respectively. Western blotting was used to detect collagen I, collagen III, alpha-smooth muscle actin (a-SMA), RASA1, p-Akt/t-Akt, p-MEK1/2/t-MEK1/2, and p-ERK1/2/t-ERK1/2 protein expressions, and immunofluorescence assays were used to detect the expression of α-actin, vimentin and α-SMA. Luciferase assays were carried out to determine whether miR-223 binds to RASA1. Rat models of MI were established by the ligation of the left anterior descending (LAD) coronary artery. MiR-223 inhibition in vivo was achieved via intramyocardial injections of the miR-223 sponge carried by adeno-associated virus 9 (AAV9). The cardiac function was detected by echocardiography, and cardiac fibrosis was shown by Masson’s trichrome staining. Results: miR-223 was increased in CFs compared to cardiomypcytes, and TGF-β1 treatment increased miR-223 expression in CFs. The miR-223 mimics enhanced cell proliferation and migration and collagen I, collagen III, and α-SMA protein expression in CFs, while the miR-223 inhibitors had contrasting effects and partially prevented the promoting effects of TGF-β1. qRT-PCR and western blotting revealed that miR-223 negatively regulated RASA1 expression, and the luciferase assays showed that miR-223 suppressed the luciferase activity of the RASA1 3’ untranslated region (3'UTR), indicating that miR-223 binds directly to RASA1. Similar to transfection with the miR-223 mimics, RASA1 knockdown enhanced cell proliferation and migration and collagen I, collagen III, and α-SMA protein expression in CFs. Moreover, RASA1 knockdown partially reversed the inhibitory effects of the miR-223 inhibitor on cell proliferation and migration and collagen I, collagen III, and α-SMA protein expression, indicating that the effects of miR-223 in CFs are partially mediated by the regulation of RASA1 expression. Further exploration showed that miR-223 mimics and siRASA1 promoted MEK1/2, ERK1/2 and AKT phosphorylation, while the mi...

Electrical Conduction System Remodeling in Streptozotocin-Induced Diabetes Mellitus Rat Heart

“…Cryptic amyloidogenic elements and RE1 silencing transcription factor has been shown to regulate the expression of NFs (Ching and Liem, 2009; Rebelo et al, 2016). Furthermore, miR-223 has been shown to inhibit collagen I expression via RASA1 in order to prevent cardiac functional deterioration and cardiac fibrosis (Liu X. et al, 2018). TRPV3 could also be inhibited to downregulate the expression of collagen I against cardiac fibrosis (Liu Y. et al, 2018).…”

Trimethylamine N-Oxide Exacerbates Cardiac Fibrosis via Activating the NLRP3 Inflammasome

“…Cell migration assays were assessed using a cell scratch assay and Transwell chambers (8-μm, Corning, United States) (Liu et al, 2018). Cardiac fibroblasts cultured in 6-well plates were treated with different TMAO concentrations and then subjected to a cell scratch assay with a 200 μl micropipette tip for 24 h following a protocol described previously (Liang et al, 2007).…”

Anti-Myocardial Infarction Effects of Radix Aconiti Lateralis Preparata Extracts and Their Influence on Small Molecules in the Heart Using Matrix-Assisted Laser Desorption/Ionization–Mass Spectrometry Imaging

“…After many improvements made by researchers, such as Smith and colleagues, it has become a common model for the study of MI [10,11]. In this study, a modified Smith method was performed by left anterior descending artery (LAD) ligation to develop a rat model of ST-segment elevation MI, which can well simulate the pathological characteristics of clinical myocardial ischemia-induced MI [12,13].…”