The role of the cGAS/STING pathway in skeletal muscle regeneration: modulation of inflammation, macrophage polarization, and oxidative stress

BACKGROUND: Skeletal muscle regeneration is essential for restoring muscle structure and function following injury. This process is influenced by various signaling pathways. Recent studies suggest that cGAS/STING signaling, which is known for its role in innate immunity, may also play a crucial role in tissue regeneration. This study investigated the regulatory role of the cGAS/STING pathway in skeletal muscle regeneration. METHODS: Skeletal muscle injury was induced via intramuscular injection of cardiotoxin (CTX) into the tibialis anterior (TA) muscle of mice. Genetic knockout models of cGAS and STING, as well as treatment with a STING agonist (DMXAA), were used to explore the role of the pathway in muscle regeneration. Histological analysis, flow cytometry, RNA extraction, and gene expression analysis were performed to evaluate muscle tissue morphology, macrophage infiltration, and the expression of inflammatory and oxidative stress markers. RESULTS: STING expression was significantly increased following injury. Treatment with a STING agonist impaired muscle regeneration, characterized by reduced muscle fiber dimensions, elevated pro-inflammatory macrophage infiltration, and increased oxidative stress. In contrast, cGAS or STING knockout enhanced muscle regeneration and promoted the accumulation of anti-inflammatory macrophages. CONCLUSIONS: The cGAS/STING pathway plays a critical role in skeletal muscle regeneration by influencing inflammation, macrophage polarization, and oxidative stress.