ANO1 regulates cardiac fibrosis via ATI-mediated MAPK pathway

Cardiac fibrosis is associated with most of heart diseases, but its molecular mechanism remains unclear. Anoctamin-1 (ANO1), a calcium-activated chloride channels (CaCCs) protein, plays a critical role in various pathophysiological processes. In the current study, we identified ANO1 expression in myocardial infarction (MI) model of rat and verified the role of ANO1 in cardiac fibrosis using transcriptomics combined with RNAi assays. we found that ANO1 expression was increased during the first two weeks, and decreased in the third week after MI. Fluorescence double labeling showed that ANO1 was mainly expressed in cardiac fibroblasts (CFs) and displayed an increased expression in CFs with proliferation tendency. The proliferation and secretion of CFs were markedly inhibited by knockdown of ANO1. RNA-Seq showed that most of the downregulation genes were related to the proliferation of CFs and cardiac fibrosis. After ANO1 knockdown, the expressions of angiotensin II type 1 receptor (AT1R) and cell nuclear proliferation antigen were markedly reduced, and the phosphorylation levels of MEK and ERK1/2 was decreased significantly, indicating that ANO1 regulate cardiac fibrosis through ATIR-mediated MAPK signaling pathway. These findings would be useful for the development of therapeutic strategies targeting ANO1 to treat and prevent cardiac fibrosis.