AUTHOR=Dai Lei , Xie Yang , Zhang Wenjun , Zhong Xiaodan , Wang Mengwen , Jiang Hongcheng , He Zhen , Liu Xiaolei , Zeng Hesong , Wang Hongjie 

TITLE=Weighted Gene Co-Expression Network Analysis Identifies ANGPTL4 as a Key Regulator in Diabetic Cardiomyopathy via FAK/SIRT3/ROS Pathway in Cardiomyocyte

JOURNAL=Frontiers in Endocrinology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2021.705154

DOI=10.3389/fendo.2021.705154

ISSN=1664-2392

ABSTRACT=<sec><title>Background</title><p>Diabetic cardiomyopathy (DbCM) is characterized by initial impairment of left ventricular relaxation followed by contractile dysfunction. Despite intensive research, the exact mechanism remains so far unsolved.</p></sec><sec><title>Methods</title><p>We constructed weighted gene co-expression network analysis (WGCNA) to screen gene modules that were closely related with DbCM based on the GSE5606 dataset, which contained expression data of the cardiac left ventricle in a rodent model of streptozotocin (STZ)-induced DbCM. Then, the most related hub gene, angiopoietin-like 4 (ANGPTL4), was selected for functional <italic>ex vivo</italic> and <italic>in vitro</italic> assays. In our experiments, STZ-induced diabetic mice (C57BL/6J) and human cardiomyocytes (AC16) were used to study the functional roles and potential mechanisms of ANGPTL4 in DbCM.</p></sec><sec><title>Results</title><p>WGCNA analysis revealed the yellow and green modules were most correlated with DbCM, and identified ANGPTL4 as one of the most significantly upregulated hub genes (<italic>ANGPTL4</italic>, <italic>ACOT1</italic>, <italic>DECR1</italic>, <italic>HMGCS2</italic>, and <italic>PDK4</italic>). Consistent with the bioinformatic analysis, the amount of ANGPTL4 was significantly upregulated in diabetic mouse heart. DbCM group, compared with the control group, had increased phosphorylation of focal adhesion kinase (FAK), reduced SIRT3 expression, increased SOD2 acetylation, upregulated NADPH oxidase activation, elevated reactive oxygen species (ROS) produciton, and enhanced apoptosis in the diabetic mouse heart. Moreover, ANGPTL4 induced apoptosis <italic>via</italic> FAK/SIRT3/ROS pathway in human cardiomyocytes (AC16) under high glucose condition <italic>in vitro.</italic>These effects were abrogated by treatment of two independent siRNA for ANGPTL4, whereas exogenous recombinant ANGPLT4 protein treatment exacerbated those effects in AC16.</p></sec><sec><title>Conclusion</title><p>We found <italic>ANGPTL4</italic>, <italic>ACOT1</italic>, <italic>DECR1</italic>, <italic>HMGCS2</italic>, and <italic>PDK4</italic> were significantly increased in diabetic heart. ANGPTL4 could promote cardiac apoptosis <italic>via</italic> a FAK/SIRT3/ROS dependent signaling pathway in DbCM.</p></sec>