Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Department of Spinal Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China.
Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Department of Spinal Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China; Orthopaedic Research Institute, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China.
Osteoarthritis Cartilage. 2022 Jul;30(7):998-1011. doi: 10.1016/j.joca.2022.03.011. Epub 2022 Apr 8.
The molecules released from cells undergoing necrosis are recognized as alarmins, and S100A8/9, a typical alarmin, is associated with several inflammation-related diseases. This study was to investigate the molecular role of S100A8/A9 on the process of intervertebral disc degeneration (IVDD) and inflammation-related pain.
The expression pattern of S100A8/A9 in different degenerated human nucleus pulposus (NP) tissues were measured by Real-time quantitative reverse transcription PCR (RT-qPCR) and immunohistochemical (IHC). The effects of S100A8/A9 on matrix production were assessed by RT-qPCR, western blotting, and cell immunofluorescence. Involvement of TLR4 and NF-κB signaling pathways were studied by pharmachemical inhibitors and small interfering RNAs (siRNAs). The development of degenerative and pain features in the IVDD model were examed by IHC and pain-behavior testing.
The expression of S100A8/A9 was significantly elevated in severely degenerated human NP tissue with similar expression pattern of TNF-α. In NP cells, S100A8/A9 increased MMP-3/13, TNF-α, IL-6 expression and inhibited aggrecan and collagen II expression. RT-qPCR and western blotting showed that the regulatory effects of S100A8/A9 on IVD were TLR4 dependent. Pharmacological inhibition or siRNA knockdown of the NF-κB signaling attenuated S100A8/A9-induced upregulation of MMP-3/13, TNF-α and IL-6. In vivo, S100A9 inhibitor treatment inhibited disc-puncture induced IVDD and inflammation-related pain.
This study showed that S100A8/A9 bound to TLR4 and increased the expression of MMPs, TNF-α, and IL-6 through NF-κB signaling pathways in NP cells. Furthermore, S100A8/A9 inhibitor could prevent development of IVDD and inflammation-related pain in the rat model.
细胞坏死时释放的分子被识别为警报素，S100A8/9 是一种典型的警报素，与几种炎症相关疾病有关。本研究旨在探讨 S100A8/A9 在椎间盘退变（IVDD）和炎症相关疼痛过程中的分子作用。
通过实时定量逆转录 PCR（RT-qPCR）和免疫组织化学（IHC）测量不同退变人髓核（NP）组织中 S100A8/A9 的表达模式。通过 RT-qPCR、western blot 和细胞免疫荧光评估 S100A8/A9 对基质产生的影响。通过药物抑制剂和小干扰 RNA（siRNA）研究 TLR4 和 NF-κB 信号通路的参与。通过 IHC 和疼痛行为测试检查 IVDD 模型中退行性和疼痛特征的发展。
S100A8/A9 在严重退变的人 NP 组织中表达明显升高，与 TNF-α 的表达模式相似。在 NP 细胞中，S100A8/A9 增加了 MMP-3/13、TNF-α、IL-6 的表达，抑制了聚集蛋白聚糖和胶原 II 的表达。RT-qPCR 和 western blot 表明，S100A8/A9 对 IVD 的调节作用依赖于 TLR4。NF-κB 信号的药理学抑制或 siRNA 敲低减弱了 S100A8/A9 诱导的 MMP-3/13、TNF-α 和 IL-6 的上调。在体内，S100A9 抑制剂治疗抑制了椎间盘穿刺诱导的 IVDD 和炎症相关疼痛。
本研究表明，S100A8/A9 与 TLR4 结合，并通过 NF-κB 信号通路增加 NP 细胞中 MMPs、TNF-α 和 IL-6 的表达。此外，S100A8/A9 抑制剂可防止大鼠模型中 IVDD 和炎症相关疼痛的发展。
