Panzhou Renze Hospital, Panzhou, Guizhou, China.
Guizhou University Medical College, Guiyang, Guizhou, China.
J Gene Med. 2024 Jan;26(1):e3656. doi: 10.1002/jgm.3656.
The induction of cardiomyocyte (CM) proliferation is a promising approach for cardiac regeneration following myocardial injury. MicroRNAs (miRNAs) have been reported to regulate CM proliferation. In particular, miR-431 expression decreases during cardiac development, according to Gene Expression Omnibus (GEO) microarray data. However, whether miR-431 regulates CM proliferation has not been thoroughly investigated.
We used integrated bioinformatics analysis of GEO datasets to identify the most significantly differentially expressed miRNAs. Real-time quantitative PCR and fluorescence in situ hybridization were performed to determine the miRNA expression patterns in hearts. Gain- and loss-of-function assays were conducted to detect the role of miRNA in CM proliferation. Additionally, we detected whether miR-431 affected CM proliferation in a myocardial infarction model. The TargetScan, miRDB and miRWalk online databases were used to predict the potential target genes of miRNAs. Luciferase reporter assays were used to study miRNA interactions with the targeting mRNA.
First, we found a significant reduction in miR-431 levels during cardiac development. Then, by overexpression and inhibition of miR-431, we demonstrated that miR-431 promotes CM proliferation in vitro and in vivo, as determined by immunofluorescence assays of 5-ethynyl-2'-deoxyuridine (EdU), pH3, Aurora B and CM count, whereas miR-431 inhibition suppresses CM proliferation. Then, we found that miR-431 improved cardiac function post-myocardial infarction. In addition, we identified FBXO32 as a direct target gene of miR-431, with FBXO32 mRNA and protein expression being suppressed by miR-431. FBXO32 inhibited CM proliferation. Overexpression of FBXO32 blocks the enhanced effect of miR-431 on CM proliferation, suggesting that FBXO32 is a functional target of miR-431 during CM proliferation.
In summary, miR-431 promotes CM proliferation by targeting FBXO32, providing a potential molecular target for preventing myocardial injury.
诱导心肌细胞（CM）增殖是心肌损伤后心脏再生的一种有前途的方法。据基因表达综合数据库（GEO）微阵列数据显示，微小 RNA（miRNA）已被报道可调节 CM 增殖。特别是，miR-431 的表达在心脏发育过程中会降低。然而，miR-431 是否调节 CM 增殖尚未得到深入研究。
我们使用 GEO 数据集的综合生物信息学分析来确定差异表达最显著的 miRNA。实时定量 PCR 和荧光原位杂交用于确定心脏中 miRNA 的表达模式。通过增益和损失功能测定来检测 miRNA 在 CM 增殖中的作用。此外，我们检测了 miR-431 是否在心肌梗死模型中影响 CM 增殖。TargetScan、miRDB 和 miRWalk 在线数据库用于预测 miRNA 的潜在靶基因。荧光素酶报告基因测定用于研究 miRNA 与靶向 mRNA 的相互作用。
首先，我们发现 miR-431 水平在心脏发育过程中显著降低。然后，通过 miR-431 的过表达和抑制，我们通过 5-乙炔基-2'-脱氧尿苷（EdU）、pH3、Aurora B 和 CM 计数的免疫荧光测定，以及 miR-431 抑制对 CM 增殖的抑制，证明了 miR-431 促进体外和体内 CM 增殖。然后，我们发现 miR-431 改善了心肌梗死后的心脏功能。此外，我们确定 FBXO32 是 miR-431 的直接靶基因，miR-431 抑制 FBXO32 mRNA 和蛋白表达。FBXO32 抑制 CM 增殖。FBXO32 的过表达阻断了 miR-431 对 CM 增殖的增强作用，表明 FBXO32 是 miR-431 在 CM 增殖过程中的功能靶基因。
综上所述，miR-431 通过靶向 FBXO32 促进 CM 增殖，为预防心肌损伤提供了一个潜在的分子靶标。
