Purpose

Determine whether decorin is immuno-stimulatory to rat tail IVD cells and to characterize the mechanical consequence of inflammation at the whole rat tail IVD level.

Methods

Cultured rat tail annulus fibrosus (AF) cells were exposed to decorin, a resident IVD small leucine-rich proteoglycan (SLRP), with and without the presence of a toll-like receptor (TLR) 4 inhibitor, TAK-242. Resultant expression of pro-inflammatory cytokine and chemokines (MCP-1; MIP-2; RANTES; IL-6; TNFα) were quantified over 24 h. Whole rat tail IVD cultures (n = 50) were also treated with decorin (two concentrations: 0.5 and 5.0 μg/mL) with and without TAK-242 (via nucleus pulpous injection with a 33-gauge needle), and resultant mechanical properties were measured.

Results

AF cells exposed to decorin showed significant increases in pro-inflammatory cytokine and chemokine production; this was significantly blunted with the presence of TAK-242. Whole IVDs injected with decorin showed a dose-dependent decrease in neutral zone and tensile stiffness and an increase in neutral zone size. When TAK-242 was injected into the IVD with the decorin, mechanical stiffness was preserved and not different from sham controls (injected with PBS).

Conclusion

AF cells are capable of detecting decorin and inducing inflammation. Decorin further resulted in a functional deterioration in IVD mechanical integrity. TAK- 242, a TLR4 inhibitor, blunted chemokine production at the cellular level and preserved mechanical stiffness in the whole IVD.

中文翻译：

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在大鼠尾椎间盘中，核心蛋白聚糖的免疫刺激能力及其引起的炎症的机械后果。

目的

确定核心蛋白聚糖是否对大鼠尾部IVD细胞具有免疫刺激作用，并表征整个大鼠尾部IVD水平炎症的机械后果。

方法

将培养的大鼠尾部纤维环（AF）细胞暴露于得林蛋白（decorin），这是一种常驻IVD小富亮氨酸蛋白聚糖（SLRP），有无Toll样受体（TLR）4抑制剂TAK-242。促炎性细胞因子和趋化因子（MIP-2; RANTES; IL-6; MCP-1的TNF表达所得的α）超过24小时进行定量。整个大鼠尾部IVD培养物（n  = 50）也用有芯蛋白（两种浓度：0.5和5.0μg/ mL）在有或没有TAK-242的情况下（通过33号针头髓核注射）处理，得到的机械性能为测量。

结果

暴露于decorin的AF细胞显示促炎性细胞因子和趋化因子的产生显着增加。TAK-242的存在明显减弱了这种作用。注射了decorin的整个IVD显示中性区和拉伸刚度的剂量依赖性降低以及中性区大小的增加。当将TAK-242与除芯蛋白一起注射到IVD中时，保留了机械刚度，与假对照（注射PBS）没有区别。

结论

AF细胞能够检测核心蛋白聚糖并诱导炎症。Decorin进一步导致IVD机械完整性的功能下降。TAK-242，一种TLR4抑制剂，在细胞水平上抑制了趋化因子的产生，并在整个IVD中保持了机械刚度。