MicroRNA(miRNA)can reduce the stability of the messenger RNA(mRNA)or inhibit the transla-tion of the messenger RNA by targeting its 3'-untranslated region(UTR),thereby negatively regulate the expression of the target gene.Diverse RNA transcripts including mRNAs;pseudogenes;long non-coding RNAs(LncRNA)and circu-lar RNAs(circRNAs)can competitively combine with the same miRNAs by microRNA response elements(MREs),re-moving or reducing the inhibition of genes targedted by the miRNAs and regulating the expression of the target genes. These RNA transcripts are called competitive endogenous RNA (ceRNA),and this new post-transcription regulation model is called ceRNA hypothesis.CeRNA not only participates in the proliferation,differentiation and aging of normal cells,but also plays an important role in the pathogenesis of tumor and cardiovascular diseases(CVD).This paper re-viewed the studies about ceRNA in cardiovascular diseases in recent years.

Objective To explore the effect of reduced alpha - cardiac actin 1(ACTC1)gene expression on the rat embryonic cardiomyocytes H9C2 cell apoptosis and its mechanism. Methods The rat embryonic cardiomyocytes H9C2 cell was cultivated;the rat embryonic cardiomyocytes H9C2 cell was transfected with ACTC1 - small interfering RNA(siRNA),and at 24 h,48 h,72 h after transfection,the cells were collected for extraction and purification of RNA, the real - time quantitative PCR(qPCR)method was used to detect the expression level of ACTC1 gene;and the termi-nal deoxynucleotidyl transferase - mediated dUTP - biotin nick end labeling assay(TUNEL)method was used to ex-plore the effect of reduced ACTC1 gene expression on the rat embryonic cardiomyocytes H9C2 cell apoptosis. Western blot was used to detect the expression of Cyto C,cysteine - containing aspartate - specific proteases(Caspase)- 3, Caspase - 8,Caspase - 9,Bcl - 2 and Bax. Results The expression of ACTC1 mRNA detected by qPCR decreased compared with that of the scramble siRNA group in 24 h,48 h,72 h(0. 80 vs. 1. 00,0. 20 vs. 1. 00,0. 25 vs. 1. 00),and in the ACTC1 - siRNA group decreased significantly at 48 h,72 h,and the difference was statistically significant(t =4. 245,P < 0. 05);TUNEL positive cells rate significantly increased in the ACTC1 - siRNA group(80％)compared with that in the scramble siRNA group(20％),and the difference was statistically significant(P < 0. 05);Western blot also confirmed that the expression of Caspase - 3,Caspase - 9,Cyto C and Bax/ Bcl - 2 were accordingly increased (0. 91 ± 0. 12 vs. 0. 59 ± 0. 01,0. 48 ± 0. 09 vs. 0. 24 ± 0. 03,0. 92 ± 0. 03 vs. 0. 45 ± 0. 01,2. 25 ± 0. 26 vs. 1. 16 ± 0. 12),and the differences were statistically significant(t = 2. 821,7. 336,2. 420,0. 798,all P < 0. 05);but the expre-ssion of Caspase - 8 had no obvious change,and the difference was not statistically significant (P > 0. 05 ). Conclusions Reduced ACTC1 gene expression can induce the rat embryonic cardiomyocytes H9C2 cell apoptosis perhaps mainly through endogenous mitochondrial signal transduction pathways.