Li Zhang, Wenya Li, Mingli Zhu, Hanyuhui Yang, Yilina Bai, Bing Sun, Yiming Xing
Our findings identify CSRP3 as a critical regulator of porcine muscle regeneration, with minimal impact in mice. These results suggest that strategically engineered porcine SCs, through CSRP3 modulation, could improve the effectiveness of xenotransplantation-based therapies for muscle repair.
BACKGROUND: Skeletal muscle function deteriorates with injury, disease, or aging. While stem cell therapies offer therapeutic potential, concerns remain regarding the safety and efficacy of transplanted cells. Satellite cells (SCs), the primary endogenous stem cells responsible for muscle repair, demonstrate safe transplantation but limited clinical effectiveness. A deeper understanding of the mechanisms regulating SC activation and differentiation is critical for improving muscle regeneration strategies.
METHODS: We examined the role of CSRP3 in SC-mediated muscle repair using injury models and myoblast differentiation assays. We compared its function in pigs and mice, employing genetic approaches, CSRP3 knockdown (CSRP3KD), Csrp3-/- and overexpression (CSRP3OE), to assess its impact on muscle regeneration. Additionally, we investigated the AKT-SERCA2 signaling axis and its downstream effects on calcium homeostasis, mitochondrial function, and myogenic differentiation.
RESULTS: CSRP3 was essential for muscle regeneration and SC differentiation in pigs but not in mice. Genetic ablation of CSRP3 (CSRP3KD) impaired porcine SC differentiation and reduced regenerative capacity, while CSRP3 overexpression (CSRP3OE) enhanced these processes. Mechanistically, CSRP3 deficiency disrupted AKT-SERCA2 signaling, leading to elevated intracellular Ca2⁺, mitochondrial dysfunction, and MYOG protein degradation. Pharmacological AKT activation rescued differentiation defects in CSRP3-deficient cells. Notably, Csrp3-/- mice showed normal SC differentiation and AKT-SERCA2 activity, highlighting a species-specific regulatory role for CSRP3.
CONCLUSIONS: Our findings identify CSRP3 as a critical regulator of porcine muscle regeneration, with minimal impact in mice. These results suggest that strategically engineered porcine SCs, through CSRP3 modulation, could improve the effectiveness of xenotransplantation-based therapies for muscle repair.