ZEB1 Is a Key Regulator of Cardiomyocyte Structure and Function

BackgroundOur previous work identified the transcription factor "Zinc Finger E-Box Binding Homeobox 1" (ZEB1) as a downstream effector of Cytoplasmic Polyadenylation Element Binding Protein 4 (CPEB4), an RNA-binding protein responsive to cardiac stress. While ZEB1 is known for its role in cancer metastasis and epithelial-to-mesenchymal transition (EMT), its function in cardiomyocytes is not well understood. Based on previous findings, we hypothesize that ZEB1 is essential for maintaining the structural integrity and mitochondrial function of cardiomyocytes. MethodsAAV9-Zeb1 was used for the overexpression of Zeb1. Using a myosin heavy chain alpha (MHC) Cre system, we created a Zeb1 conditional knockout mouse. To evaluate cardiac function and structure, we used echocardiography, electron microscopy, immunohistochemistry. We identified differentially expressed genes following Zeb1 deletion using RNA-seq and determined direct Zeb1 target genes by integrating this transcriptome data with a Zeb1 ChIP-seq dataset. ResultsZEB1 deletion leads to sarcomere damage, mitochondrial dysfunction, and dedifferentiation, with more pronounced effects in females. Overexpression promotes hypertrophic remodeling. Echocardiographic analysis showed progressive systolic dysfunction, and histology revealed sarcomeric disarray, again especially in females. A tamoxifen-inducible ZEB1 knockout mouse model only confirmed ZEB1s crucial role in fully differentiated cardiomyocytes in female mice. Integrated analysis of RNA-seq and ChIP-seq revealed that Zeb1 directly regulated mitochondrial genes, thereby playing a critical role cardiomyocyte energy supply and having secondary effects on cardiac structure and function. ConclusionsZEB1 is critical for cardiomyocyte homeostasis, and maintaining its function is necessary for normal cardiac performance and structure.