GsMTx4-loaded GelMA promotes tendon regeneration and suppresses heterotopic ossification via the Apelin signaling pathway

Tendon injuries pose significant challenges in both athletes and the general population, often leading to prolonged healing, impaired functionality, and increased risk of re-injury. Current treatment options are limited and often yield unfavorable outcomes. Given that tendons are highly mechanosensitive tissues, recent studies highlight the crucial role of mechanotransduction in tissue repair. Piezo1, a mechanosensitive ion channel, has been recognized as a crucial factor attributing to many pathological processes in various tissues, but its specific role in tendon healing has not been previously explored. This study aimed to investigate the potential therapeutic benefits of GsMTx4-loaded GelMA on tendon regeneration and the prevention of heterotopic ossification following injury. Our findings indicate that following tendon injuries, Piezo1 expression was elevated. Activation of Piezo1 with Yoda1 suppressed osteogenic differentiation while promoting chondrogenic differentiation of tendon-derived stem cells. Treatment with GsMTx4 enhanced tendon healing and mitigated the formation of heterotopic ossification. RNA sequencing further implicated the Apelin signaling pathway in these processes, and inhibition of this pathway using ML221 significantly suppressed HO formation, suggesting a pivotal role for Apelin in tendon healing and ossification. Additionally, short-term immobilization was found to attenuate heterotopic ossification by modulating Piezo1 activity. Thus, inhibition of Piezo1 enhances tendon healing and reduces heterotopic ossification, potentially through the Apelin signaling pathway. These results underscore the critical role of Piezo1 in tendon biology and highlight the potential of targeting mechanosensitive ion channels, especially Piezo1, as a novel therapeutic approach for promoting tendon regeneration and preventing heterotopic ossification.