背景：骨关节炎软骨细胞的退化是由于一系列的机械因素、炎性递质、生化因素，尤其是基质金属蛋白酶和活性氧等共同作用导致的。姜黄素在体外已被证明是一种有效地活性氧清除剂和活性氮提供剂，但保护关节软骨抑制骨关节炎作用和机制尚不明确。 目的：分析姜黄素防止骨关节炎中软骨损伤的作用机制。 方法：SD大鼠30只随机分为假手术组15只和模型组15只。模型组建立大鼠创伤性骨关节炎模型(阳性对照组)，分离软骨细胞进行体外培养，使用姜黄素(姜黄素组)和特异性的核因子κB抑制剂(PDTC组)共培养软骨细胞24 h，Western Blotting和免疫荧光检测核因子κB P65核内外表达情况。RT-qPCR检测细胞Ⅱ型胶原、基质金属蛋白酶1、基质金属蛋白酶13的表达。 结果与结论：Western Blotting检测显示阳性对照组P65主要在细胞核中表达，细胞浆中表达较少；姜黄素组P65主要在细胞浆中表达，细胞核中表达较少。免疫荧光观察阳性对照组核因子κB 均有不同程度的核转位，核转位细胞的核因子κB P65荧光标记主要浓集于核区；阴性对照组、姜黄素组和PDTC组核转位细胞的核因子κB P65荧光标记主要浓集于胞质区。实时荧光定量RT-qPCR检测显示姜黄素组基质金属蛋白酶1、基质金属蛋白酶13的表达显著低于阳性对照组，而Ⅱ型胶原的表达显著高于阳性对照组。结果说明，姜黄素能够通过抑制骨关节炎模型中软骨细胞核因子κB信号通路活化，抑制核因子κB P65核转位，抑制软骨细胞释放基质金属蛋白酶1、基质金属蛋白酶13的表达，增加Ⅱ型胶原的含量，保护软骨细胞，延缓软骨退变。%BACKGROUND:Mechanical, inflammatory, and biochemical factors, particularly matrix metaloproteinases and reactive oxygen lead to chondrocyte degeneration in osteoarthritis. Curcumin has been shown to be a potent antioxidant; however, its protective effects against chondrocyte degeneration in osteoarthritis remain unclear. OBJECTIVE:To investigate the potential molecular mechanisms underlying the protective effects of curcumin on articular cartilage of osteoarthritis in rats. METHODS:A total of 30 Sprague-Dawley rats were used and randomly divided into model group (positive control,n=15) and normal group (negative control,n=15). Rat models of traumatic osteoarthritis were established, and then cartilage cels were isolated from articular cartilage and culturedin vitro. Chondrocytes were treated with curcumin (curcumin group) or PDTC (an inhibitor of nuclear factor-kappa B) for 24 hours. The expression level of nuclear factor-kappa B P65 in nucleus and cytoplasm in chondrocytes were determined by western blot assay and immunofluorescence. Moreover, mRNA expressions of type II colagen, matrix metaloproteinase-1 and -13 were analyzed using RT-qPCR. RESULTS AND CONCLUSION: Nuclear factor-kappa B P65 protein was mainly expressed in nucleus, but few in cytoplasm in positive control group; the reversed results were found in the curcumin group. Nuclear translocation of nuclear factor-kappa B P65 was observed mainly in nucleus in the positive control group; however, that was observed mainly in cytoplasm in the negative control, curcumin, and PDTC groups. Matrix metaloproteinase-1 and -13 mRNA expressions were significantly decreased, while type II colagen mRNA expression was significantly increased in the curcumin group compared with the positive control group. These findings indicated that curcumin protect chondrocytes against degeneration through inhibiting the activation of nuclear factor-kappa B signaling pathway, suppressing nuclear translocation of nuclear factor-kappa B P65 and inhibiting the expressions of matrix metaloproteinase-1 and -13, which are responsible for upregulation of type II colagen expression.
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