Effect of miR-195-5p on myocardial fibrosis in atrial fibrillation rats by targeting SMAD homolog 7 to regulate TGF-β1
10.3969/j.issn.1009-0126.2025.01.007
- VernacularTitle:微小RNA-195-5p靶向SMAD同源物7调控转化生长因子β1影响心房颤动大鼠心肌纤维化
- Author:
Ailing YANG
1
;
Ling LIN
1
;
Mingyue SHEN
1
;
Mei HOU
1
;
Rong SU
1
;
Hu ZHANG
1
;
Yunfei LI
1
Author Information
1. 650031 昆明医科大学第一附属医院心脏内科
- Publication Type:Journal Article
- Keywords:
atrial fibrillation;
rats;
circulating microRNA;
transforming growth factor beta;
Smad proteins;
myocardial fibrosis;
microRNA-195-5p
- From:
Chinese Journal of Geriatric Heart Brain and Vessel Diseases
2025;27(1):27-32
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effect and mechanism of miR-195-5p on myocardial fibro-sis in rats with atrial fibrillation(AF).Methods A total of 72 male SD rats were randomly divid-ed into control group,AF group,negative control group,miR-195-5p inhibitor group,recombinant adeno-associated virus serotype 9(rAAV9)group(miR-195-5p inhibitor+rAAV9-negative con-trol),and combination group[miR-195-5p inhibitor+rAAV9-siRNA-SMAD homolog 7(Smad)],with 12 rats in each group.Except for the control group,the rats in the other groups were inflicted to construct AF model.After receiving corresponding intervention measures,elec-trocardiography was conducted to record the incidence and the duration of AF.HE staining and Masson staining were used to observe the pathological changes and fibrosis in the myocardial tis-sues,respectively.qRT-PCR was applied to detect the mRNA levels of miR-195-5p and Smad7,and Western blotting was performed to detect the expression of TGF-β1,Smad2,p-Smad2,Smad3,p-Smad3,Smad7,Collagen-Ⅰ and Collagen-Ⅲ in the myocardial tissues.Dual luciferase assay was used to verify the regulatory effect of miR-195-5p on Smad7.Results Compared with the control group,the AF group had significantly higher AF incidence(75.0％vs 0)and longer duration(27.02±2.65 s vs 0 s),larger collagen volume fraction(CVF)[(14.47±0.89)％vs(2.12±0.35)％],and increased expression levels of miR-195-5p(3.27±0.21 vs 1.00±0.10),TGF-β1(0.76±0.08 vs 0.23±0.04),Collagen-Ⅰ(0.58±0.07 vs 0.20±0.04),Collagen-Ⅲ(0.46±0.05 vs 0.11±0.02),p-Smad2/Smad2(0.92±0.10 vs 0.37±0.05),and p-Smad3/Smad3(0.65±0.06 vs 0.14±0.03),but notably decreased expression of Smad7 at mRNA(0.32±0.06 vs 1.02±0.09)and protein(0.19±0.03 vs 0.58±0.07)levels in the myocardial tissues(P＜0.05).The AF incidence and duration,CVF,miR-195-5p level,and protein levels of TGF-β1,Collagen-Ⅰ,Colla-gen-Ⅲ,p-Smad2/Smad2,and p-Smad3/Smad3 were significantly decreased,and the mRNA and protein levels of Smad7 were significantly increased in the miR-195-5p inhibitor group than the AF group and the negative control group(P＜0.05).The combined treatment increased the inci-dence and duration of AF,CVF,myocardial TGF-β1,Collagen-Ⅰ,Collagen-Ⅲ,p-Smad2/Smad2 and p-Smad3/Smad3 expression levels,and decreased the mRNA and protein expressions of Smad7 when compared with the miR-195-5p inhibitor group and the rAAV9 group(P＜0.05).Conclusion Down-regulation of miR-195-5p alleviates myocardial fibrosis in AF rats probably by targeting Smad7 to inhibit TGF-β1 signaling.
