Abstract：
Disruption of intervertebral disc (IVD) homeostasis caused by oxidative stress and nucleus pulposus cell (NPC) senescence is a main cause of intervertebral disc degeneration (IDD). The sonic hedgehog (Shh) pathway plays an important role in IVD development, but its roles in IDD are unknown. This study aimed to investigate the effects of the Shh pathway on the alleviation of IDD and the related mechanisms. In vivo, the effect of the Shh pathway on IVD homeostasis was studied by intraperitoneal injection of recombinant Shh (rShh) and GANT61 based on puncture-induced IDD. GANT61, lentivirus-coated sh-Gli1 and rShh were used to investigate the role and mechanism of the Shh pathway in NPCs based on senescence induced by Braco19 and oxidative stress induced by TBHP. Shh pathway expression decreased, and senescence and oxidative stress increased with age. Intraperitoneal injection of rShh activated the Shh pathway to suppress oxidative stress and NPC senescence and consequently alleviated needle puncture-induced IDD. In vitro, the Shh pathway upregulated glutathione peroxidase 4 (GPX4) expression to suppress oxidative stress and senescence in NPCs. Moreover, GPX4 suppression in NPCs by si-GPX4 significantly reduced the protective effect of the Shh pathway on oxidative stress and senescence in NPCs. Our results demonstrate for the first time that the Shh pathway plays a key role in the alleviation of IDD by suppressing oxidative stress and cell senescence in NP tissues. This study provides a new potential target for the prevention and reversal of IDD.
摘要：
氧化应激破坏椎间盘(IVD)稳态和髓核细胞(NPC)衰老是椎间盘退变(IDD)的主要原因。Sonichedgehog(Shh)通路在IVD发生发展中起着重要作用,但它在IDD中的作用是未知的。本研究旨在探讨Shh通路在减轻IDD中的作用及相关机制。在体内,基于穿刺诱导的IDD，通过腹腔注射重组Shh（rShh）和GANT61研究了Shh途径对IVD稳态的影响。GANT61，慢病毒包被的sh-Gli1和rShh用于基于Braco19诱导的衰老和TBHP诱导的氧化应激研究Shh途径在NPCs中的作用和机制。Shh通路表达降低，衰老和氧化应激随年龄增长而增加。腹膜内注射rShh激活了Shh途径以抑制氧化应激和NPC衰老，从而减轻了针刺诱导的IDD。体外，Shh途径上调谷胱甘肽过氧化物酶4（GPX4）的表达以抑制NPCs的氧化应激和衰老。此外，si-GPX4抑制NPCs中的GPX4显著降低了Shh途径对NPCs中氧化应激和衰老的保护作用。我们的研究结果首次表明，Shh通路通过抑制NP组织中的氧化应激和细胞衰老在减轻IDD中起关键作用。本研究为预防和逆转IDD提供了新的潜在靶点。
