MicroRNA‑146a attenuates isoproterenol‑induced cardiac fibrosis by inhibiting FGF2

Figures

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  Figure 1. miR-146a-5p expression is downregulated in ISO-induced CFs and rat heart. (A) H&E and Masson staining determined myocardial collagen deposition in myocardial tissue following ISO injection. (B) CK, (C) CK-MB and (D) cTnI concentrations were measured in the serum of ISO-treated and normal control rats. RT-qPCR analysis determined expression levels of (E) miR-146a-5p and (F) collagen I and α-SMA in ISO-treated rat heart tissue. RT-qPCR analysis determined levels of (G) miR-146a-5p and (H) collagen I and α-SMA in ISO-treated CFs. *P<0.05 vs. saline. miR, microRNA; ISO, isoproterenol; CF, cardiac fibroblast; H&E, hematoxylin and eosin; CK, creatine kinase; CK-MB, creatine kinase isozyme; cTnI, cardiac troponin I; RT-q, reverse transcription-quantitative; α-SMA, α-smooth muscle actin.

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  Figure 2. miR-146a-5p suppresses viability and differentiation of ISO-induced CFs. Reverse transcription-quantitative PCR analysis determined (A) miR-146a-5p and (B) collagen I and α-SMA expression levels in ISO-treated CFs transfected with NC and miR-146a-5p mimics. (C) Cell Counting Kit-8 assay showed the viability of ISO-treated CFs transfected with NC and miR-146a-5p mimics. *P<0.05 vs. NC mimics. miR, microRNA; ISO, isoproterenol; CF, cardiac fibroblast; α-SMA, α-smooth muscle actin; NC, negative control; OD, optical density.

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  Figure 3. miR-146a-5p directly targets FGF2 and FGF2 knockdown decreases collagen I and α-SMA expression levels in CFs. (A) StarBase database showed the potential binding sites between FGF2 and miR-146a-5p. (B) Luciferase reporter assay was used to determine the binding ability between FGF2 and miR-146a-5p in 293 cells. *P<0.05 vs. NC mimics. (C) RT-qPCR and (D) western blotting were used to assess the mRNA and protein levels of FGF2 in ISO-treated CFs transfected with NC or miR-146a-5p mimics or inhibitor or inhibitor. (E) RT-qPCR and (F) western blotting showed mRNA and protein levels of FGF2 in CFs transfected with siNC or siFGF2. (G) RT-qPCR analysis showed collagen I and α-SMA mRNA levels in ISO-treated CFs transfected with siNC or siFGF2. *P<0.05 vs. siNC. miR, microRNA; FGF2, fibroblast growth factor 2; α-SMA, α-smooth muscle actin; NC, negative control; CF, cardiac fibroblast; RT-q, reverse transcription-quantitative; ISO, isoproterenol; si, small interfering; WT, wild-type; MUT, mutant.

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  Figure 4. miR-146a-5p suppresses ISO-treated cardiac fibrosis by targeting FGF2. (A) RT-qPCR and (B) western blotting were performed to determine the mRNA and protein levels of FGF2 in ISO-treated CFs transfected with NC or miR-146a-5p mimics or miR-146a-5p mimics + pcDNA3.1/FGF2. (C) RT-qPCR and (D) Cell Counting Kit-8 assay determined collagen I and α-SMA expression levels, as well as viability, in ISO-treated CFs transfected with NC or miR-146a-5p mimics or miR-146a-5p mimics + pcDNA3.1/FGF2. *P<0.05. miR, microRNA; ISO, isoproterenol; FGF2, fibroblast growth factor 2; RT-q, reverse transcription-quantitative; CF, cardiac fibroblast; NC, negative control; OD, optical density.