Iron-responsive ZNF185 overexpression drives mitochondrial fission and endoplasmic reticulum stress via cytoskeletal remodeling in granulosa cells

Ovarian endometrioma (OMA), an estrogen-dependent gynecological disorder, is characterized by the presence of abundant free iron resulting from recurrent hemorrhage of endometrial cells within the cyst, which adversely affects ovarian function. However, the underlying mechanisms through which iron overload impairs ovarian function remain unclear. In this study, we stimulated KGN cells with ferric ammonium citrate (FAC) in vitro and observed dose-dependent significant alterations, including decreased mitochondrial membrane potential, increased reactive oxygen species (ROS), decreased cell viability, and elevated apoptosis rates. RNA sequencing analysis of iron-overloaded KGN cells demonstrated significant upregulation of ZNF185 expression across multiple concentration gradients and treatment durations. ZNF185 overexpression was found to disrupt F-actin dynamics, triggering a cascade of cellular events including Drp1-mediated mitochondrial hyperfission, endoplasmic reticulum stress, and cytochrome C release, ultimately leading to granulosa cell apoptosis. Importantly, knockdown of ZNF185 was shown to preserve cytoskeletal integrity and attenuate apoptotic responses under conditions of iron overload. Our findings demonstrated that ZNF185 served as a novel iron-responsive regulator involved in iron overload-induced granulosa cell apoptosis. These results might provide potential therapeutic strategies for ovarian fertility preservation in OMA patients.