ABSTRACT

Intervertebral disc degeneration (IDD) is one of the main causes of lower back pain (LBP). It results from an imbalance between the degradation and synthesis of extracellular matrix (ECM) components in nucleus pulposus (NP) cells. Atorvastatin, an HMG-CoA reductase inhibitor, plays a vital role in many diseases, such as cardiovascular disease and osteoarthritis. However, the effect of atorvastatin on IDD is unclear. Herein, we demonstrated that atorvastatin affects matrix degradation induced by TNF-α and demonstrated the mechanism by which TNF-α modulates matrix metabolism in rat NP cells. Real-time PCR, western blotting and immunofluorescence staining were performed to detect the mRNA and protein expression of related genes. mRFP-GFP-LC3 adenovirus plasmid transfection and transmission electron microscopy (TEM) were used to detect cell autophagy. NLRP3 inhibitor and lentiviral vectors containing shRNA-NLRP3 were used to show the effect of NLRP3 on autophagic flux and the NF-κB signaling pathway. The results revealed that atorvastatin might suppress matrix degradation induced by TNF-α by suppressing NLRP3 inflammasome activity and inducing autophagic flux. Moreover, atorvastatin suppressed NF-κB signaling induced by TNF-α. NF-κB signaling inhibition suppressed NLRP3 inflammasome activity, and NLRP3 inhibition suppressed NF-κB signaling activation induced by TNF-α. NLRP3 inhibition or NLRP3 knockdown induced autophagic flux in the presence of TNF-α. Overall, the present study demonstrated that atorvastatin might suppress matrix degradation induced by TNF-α and further revealed the crosstalk among NLRP3 inflammasome activity, autophagy and NF-κB signaling.

摘要

椎间盘退变（IDD）是腰痛（LBP）的主要原因之一。它是由髓核 (NP) 细胞中细胞外基质 (ECM) 成分的降解和合成之间的不平衡引起的。阿托伐他汀是一种 HMG-CoA 还原酶抑制剂，在心血管疾病和骨关节炎等许多疾病中起着至关重要的作用。然而，阿托伐他汀对 IDD 的影响尚不清楚。在此，我们证明了阿托伐他汀影响 TNF-α 诱导的基质降解，并证明了 TNF-α 调节大鼠 NP 细胞基质代谢的机制。采用real-time PCR、western blotting和免疫荧光染色检测相关基因的mRNA和蛋白表达。mRFP-GFP-LC3腺病毒质粒转染和透射电子显微镜（TEM）用于检测细胞自噬。NLRP3抑制剂和含有shRNA-NLRP3的慢病毒载体用于显示NLRP3对自噬通量和NF-κB信号通路的影响。结果表明，阿托伐他汀可能通过抑制 NLRP3 炎性体活性和诱导自噬通量来抑制 TNF-α 诱导的基质降解。此外，阿托伐他汀抑制 TNF-α 诱导的 NF-κB 信号传导。NF-κB 信号抑制抑制 NLRP3 炎性体活性，NLRP3 抑制抑制 TNF-α 诱导的 NF-κB 信号激活。NLRP3 抑制或 NLRP3 敲低在 TNF-α 存在下诱导自噬通量。总体而言，本研究表明阿托伐他汀可能抑制 TNF-α 诱导的基质降解，并进一步揭示了 NLRP3 炎性体活性、自噬和 NF-κB 信号传导之间的串扰。