乙醛脱氢酶1家族成员A2过表达对心肌细胞肥大生长及增殖的影响

Effect of overexpression of aldehyde dehydrogenase family member A2 on hypertrophic growth and proliferation of cardiomyocytes

摘要:

维甲酸信号通路在调节脊椎动物发育、细胞分化和维持组织稳态平衡中发挥重要功能。作为催化视黄醛氧化成维甲酸的关键酶，乙醛脱氢酶1家族成员A2 (aldehyde dehydrogenase 1 family member A2, Aldh1a2)在调节心脏发育过程中具有重要功能，而其在心脏疾病中发挥的功能尚不明晰。本研究通过构建和包装用于过表达Aldh1a2的腺病毒(Ad-Aldh1a2)，将其感染原代心肌细胞后分析Aldh1a2过表达对心肌细胞生物学功能的影响。结果显示心肌细胞感染Ad-Aldh1a2后能够成功实现Aldh1a2的过表达；与感染Ad-GFP的对照组相比，感染Ad-Aldh1a2的心肌细胞尺寸明显增加，胚胎期基因心房利钠肽(atrial natriuretic factor, ANF)、脑利钠肽(brain natriuretic peptide, BNP)和β-肌球蛋白重链(β-myosin heavy chain, β-MHC)表达水平上调；此外，5-乙炔基-2ʹ-脱氧尿苷(EdU)掺入实验结果显示，Aldh1a2过表达使EdU掺入阳性信号的心肌细胞比例升高，检测增殖相关基因的表达发现细胞周期蛋白D2 (cycline D2, Ccnd2)和苯并咪唑出芽抑制解除同源物蛋白-1 (budding uninhibited by benzimidazole 1, Bub1)的表达水平也明显升高。以上结果表明Aldh1a2过表达可促进心肌细胞肥大生长和增殖。本研究为进一步了解Aldh1a2在心脏疾病中的功能、发展心脏疾病的治疗策略提供了有益的基础。

Abstract:

Retinoic acid signaling pathway plays a role in regulating vertebrate development, cell differentiation, and homeostasis. As a key enzyme that catalyzes the oxidation of retinal to retinoic acid, aldehyde dehydrogenase 1 family member A2 (Aldh1a2) is involved in cardiac development, while whether it functions in heart diseases remains to be studied. In this study, we infected primary cardiomyocytes with adenovirus overexpressing Aldh1a2 (Ad-Aldh1a2) to explore the effects of Aldh1a2 overexpression on the biological function of cardiomyocytes. The results showed that the infection with Ad-Aldh1a2 realized the overexpression of Aldh1a2 in cardiomyocytes. Compared with the control group infected with Ad-GFP, the cardiomyocytes infected with Ad-Aldh1a2 showcased significantly increased size and up-regulated expression levels of the atrial natriuretic factor gene (ANF), brain natriuretic peptide gene (BNP), and β-myosin heavy chain (β-MHC). In addition, 5-ethynyl-2ʹ-deoxyuridine (EdU) incorporation assay demonstrated that Aldh1a2 overexpression increased the proportion of cardiomyocytes with positive EdU signals and upregulated the expression levels of proliferation-related genes cyclin D2 (Ccnd2) and budding uninhibited by benzimidazole 1 (Bub1). The above data indicated that overexpression of Aldh1a2 induced hypertrophic growth and proliferation of cardiomyocytes. This study provides a basis for further understanding the function of Aldh1a2 in heart diseases and developing therapies for heart diseases.