Department of Spine Surgery, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China.
Department of Orthopedics, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China.
Am J Pathol. 2024 Sep;194(9):1737-1751. doi: 10.1016/j.ajpath.2024.05.004. Epub 2024 Jun 13.
This study investigated the role of apoptosis signal-regulated kinase-1 (ASK1) in intervertebral disc degeneration (IDD). The nucleus pulposus (NP) tissues of non-IDD and IDD patients were subjected to hematoxylin and eosin, Safranin O-fast green, and immunohistochemical staining. Quantitative real-time PCR was used to assess the ASK1 mRNA level within NP tissue samples and cells. The Cell Counting Kit-8 assay, senescence-associated β-galactosidase staining, and flow cytometry were conducted to assess the viability, senescence, and apoptosis of NP cells, respectively. Extracellular matrix-related factors were detected using Western blot analysis. Furthermore, the effect of ASK1 on the IDD rat model was evaluated. Finally, c-Jun N-terminal kinase (JNK) inhibitors were used to verify the effect of the JNK/p38 signaling on IDD. ASK1 mRNA and protein were up-regulated within NP tissue samples from the IDD group, IL-1β-stimulated NP cells, and IDD rats. ASK1 inhibition promoted cell viability and repressed the senescence and apoptosis of NP cells, promoted collagen II and aggrecan, inhibited matrix metalloproteinase 3/9 and a disintegrin and metalloproteinase with thrombospondin motifs 4/5 protein levels, and increased NP cells in rat intervertebral disc tissues. ASK1 overexpression exerted the opposite effects of ASK1 inhibition on NP cells. Additionally, JNK/p38 signaling suppression could reverse the ASK1 up-regulation-induced dysfunction. In conclusion, ASK1 facilitated the senescence and apoptosis of NP cells in promoting IDD progression via the JNK/p38 pathway.
本研究探讨了凋亡信号调节激酶 1（ASK1）在椎间盘退变（IDD）中的作用。对非 IDD 和 IDD 患者的髓核（NP）组织进行苏木精和伊红、番红 O-快绿和免疫组织化学染色。采用定量实时 PCR 评估 NP 组织样本和细胞中的 ASK1 mRNA 水平。细胞计数试剂盒-8 测定、衰老相关β-半乳糖苷酶染色和流式细胞术分别用于评估 NP 细胞的活力、衰老和凋亡。采用 Western blot 分析检测细胞外基质相关因子。此外，评估了 ASK1 对 IDD 大鼠模型的影响。最后，使用 c-Jun N 端激酶（JNK）抑制剂验证 JNK/p38 信号对 IDD 的影响。在 IDD 组的 NP 组织样本、IL-1β 刺激的 NP 细胞和 IDD 大鼠中，ASK1 mRNA 和蛋白均上调。ASK1 抑制促进 NP 细胞活力，抑制衰老和凋亡，促进胶原 II 和聚集蛋白聚糖，抑制基质金属蛋白酶 3/9 和含有血栓反应蛋白基序的解整合素金属蛋白酶 4/5 蛋白水平，并增加大鼠椎间盘组织中的 NP 细胞。ASK1 过表达对 NP 细胞产生与 ASK1 抑制相反的作用。此外，JNK/p38 信号抑制可逆转 ASK1 上调诱导的功能障碍。总之，ASK1 通过 JNK/p38 通路促进 NP 细胞衰老和凋亡，从而促进 IDD 进展。
