EphA2 Silencing Attenuates IL-1β-Induced Chondrocyte Ferroptosis and Extracellular Matrix Degradation In Vitro.

This study investigated the role of erythropoietin-producing hepatocellular carcinoma receptor A2 (EphA2) in interleukin-1β (IL-1β)-induced chondrocyte injury and ferroptosis-associated alterations in osteoarthritis (OA). Primary rat chondrocytes were stimulated with IL-1β to establish an in vitro OA-like model. EphA2 was silenced using siRNA. Cell viability and apoptosis were assessed using MTT and TUNEL assays, respectively. Extracellular matrix (ECM) metabolism was evaluated by immunofluorescence and RT-qPCR. Ferroptosis-associated changes were assessed by measuring mitochondrial ferrous iron accumulation, intracellular Fe²⁺, malondialdehyde (MDA), glutathione (GSH), and the levels of ferroptosis-related proteins. IL-1β increased EphA2 expression, reduced collagen II and aggrecan expression, and increased the expression of disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5) and matrix metalloproteinase 13 (MMP-13). EphA2 silencing restored ECM homeostasis and attenuated the IL-1β-induced loss of viability and apoptosis. Moreover, EphA2 silencing reduced Fe²⁺ accumulation and lipid peroxidation, restored GSH levels, increased GPX4 and SLC7A11 expression, and decreased ACSL4 expression, consistent with the attenuation of ferroptosis-associated stress. EphA2 silencing attenuates IL-1β-induced chondrocyte injury, ECM dysregulation, and ferroptosis-associated alterations in vitro. EphA2 may contribute to ferroptosis-associated chondrocyte dysfunction in OA, warranting further mechanistic and in vivo studies.