Data_Sheet_2_Identification and Analysis of Hub Genes in Diabetic Cardiomyopathy: Potential Role of Cytochrome P450 1A1 in Mitochondrial Metabolism and STZ-Induced Myocardial Dysfunction.xlsx

Diabetic cardiomyopathy (DCM) is a primary cause of death in diabetic patients; however, its molecular mechanism is not yet clear, and there is no uniform standard for diagnosis. The aim of this study is to discover the pathogenesis and potential therapeutic targets of DCM through screening and analysis of differentially expressed genes (DEGs) in heart ventricles of DCM, and to testify the role of key hub genes in DCM-induced myocardial dysfunction. Datasets GSE4745 and GSE6880 were downloaded from the GEO database. The difference analysis, visual analysis, cluster analysis and enrichment analysis were performed by using R language, python scripts and bioinformatics software followed by the construction of protein-protein interaction (PPI) network to obtain hub genes. The DCM models were established by streptozocin (STZ) injection to the male mice. The cardiac function and the expressions of hub genes were examined by using echocardiography and real-time quantitative poly-merase chain reaction (RT-qPCR), followed by multiple statistical analyses. Bioinformatic results indicate that mitochondrial dysfunction, disturbed lipid metabolism and decreased collagen synthesis are the main causes of the DCM development. In particular, the hub gene Cyp1a1 that encodes Cytochrome P450 1A1 (CYP4501A1) enzyme has the highest connectivity in the interaction network, and is associated with mitochondrial homeostasis and energy metabolism. It plays a critical role in the oxidation of endogenous or exogenous substrates. Our RT-qPCR results confirmed that ventricular Cyp1a1 mRNA level was nearly 12-fold upregulated in DCM model compared to normal control, which was correlated with abnormal cardiac function in diabetic individuals. CYP4501A1 protein expression in mitochondria was also increased in diabetic hearts. However, we found no significant changes in collagen expressions in cardiac ventricles of mice with DCM. This study provided compact data support for understanding the pathogenesis of DCM. CYP4501A1 might be considered as a potential candidate targeting for DCM therapy. Follow-up animal and clinical verifications need to be further explored.

糖尿病心肌病（Diabetic cardiomyopathy, DCM）是糖尿病患者的首要致死病因，但其分子机制尚未明确，且目前尚无统一的诊断标准。本研究旨在通过筛选并分析糖尿病心肌病患者心室组织的差异表达基因（differentially expressed genes, DEGs），揭示糖尿病心肌病的发病机制并挖掘潜在治疗靶点，同时验证关键核心基因在糖尿病心肌病诱导的心肌功能障碍中的作用。从GEO数据库（GEO database）下载数据集GSE4745与GSE6880。本研究采用R语言、Python脚本及生物信息学软件开展差异表达分析、可视化分析、聚类分析与富集分析，随后构建蛋白质相互作用（protein-protein interaction, PPI）网络以筛选核心基因。通过向雄性小鼠注射链脲佐菌素（streptozocin, STZ）构建糖尿病心肌病模型，采用超声心动图与实时定量聚合酶链反应（real-time quantitative polymerase chain reaction, RT-qPCR）检测小鼠心脏功能及核心基因的表达水平，并开展多维度统计分析。生物信息学分析结果显示，线粒体功能障碍、脂质代谢紊乱及胶原合成减少是糖尿病心肌病发生发展的主要驱动因素。尤为关键的是，编码细胞色素P450 1A1（Cytochrome P450 1A1, CYP4501A1）的核心基因Cyp1a1在相互作用网络中连接度最高，且与线粒体稳态及能量代谢密切相关，在内源与外源底物的氧化过程中发挥核心调控作用。本研究的RT-qPCR结果证实，糖尿病心肌病模型小鼠心室组织中Cyp1a1的mRNA表达水平较正常对照组上调近12倍，且该表达变化与糖尿病个体的心脏功能异常呈显著相关；糖尿病小鼠心脏线粒体中CYP4501A1的蛋白表达水平同样升高。但本研究未观察到糖尿病心肌病模型小鼠心室组织中胶原表达存在显著变化。本研究为阐明糖尿病心肌病的发病机制提供了详实的数据支撑，CYP4501A1有望成为糖尿病心肌病治疗的潜在候选靶点，后续尚需开展更多动物实验与临床验证研究。