• Bao Huang, Jian Chen, Xuyang Zhang, Jiasheng Wang, Zeyu Zheng, Zhi Shan, Junhui Liu, Zhihai Zhu, and Fengdong Zhao.
• Department of Orthopaedics, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.
• Spine. 2019 Mar 15; 44 (6): E338-E347.

Study DesignBasic science study.ObjectiveTo illustrate supplemental alpha-2 macroglobulin (α2 M) has beneficial effects on cartilaginous endplates (CEPs) that may slow the progression of intervertebral disc (IVD) degeneration.Summary Of Background DataCEPs play a vital role in progression of intervertebral disc degenerative diseases. However, the ideal and economic therapies for CEPs degeneration are still urgently required.MethodsFirstly, we confirmed degenerative CEP characters by H&E and Safranin O fast green staining and detected increasing level of α2 M and matrix metalloproteinase 13(MMP-13) in degenerative CEP by immunohistochemistry. Then, effects of exogenous α2 M on tumor necrosis factor alpha (TNF-α)-induced CEP catabolic enzyme and anabolic molecules were evaluated by qRT-PCR, Western blotting and ELISA in cultured CEP cells obtained from rats. Furthermore, suppression of α2 M on TNF-α-induced activation of NF-кB signaling pathway was measured by Western blotting and immunofluorescence. In addition, function of α2 M on TNF-α-treated ex vivo IVDs from rats lumbar IVDs was estimated by measuring the expression of MMP-13, Sox9, aggrecan, and type II collagen in CEP area.ResultsCompared with normal CEP, level of α2 M was slightly increased in CEP from degenerative patients, whereas MMP-13 was sharply elevated. In vitro, α2 M inhibited expression and activity of MMP-3 or MMP-13 in a dose-dependent manner in rat CEP cells stimulated by TNF-α. The α2 M refrained phosphorylation of IκBα and inhibited nuclear translocation of p65. Finally, supplemental α2 M reduced expression of MMP-13, and promoted expression of Sox9, aggrecan, and type II collagen in CEP area of ex vivo IVDs cultured with TNF-α.Conclusionα2 M is not sufficiently produced to inactivate higher concentrations of catabolic factor MMP-13 found in the degenerated CEP. Supplemental α2 M protects against the progression of IVD degeneration by inhibiting effects of proinflammatory cytokines.Level Of EvidenceN/A.

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