中文摘要：

目的 比较固醇调节元件结合蛋白-2（SREBP-2）在正常软骨、骨关节炎（OA）软骨中表达,探讨SREBP-2在软骨退变过程中的表达变化.方法 正常软骨、OA膝关节软骨组织行番红素O染色、Mankin评分和抗SREBP-2免疫组化染色;正常软骨细胞随机分为对照组和白细胞介素（IL）-1β刺激组,四氮唑法（WST-1）法检测其增殖活力,实时荧光定量PCR（RT-PCR）检测目的基因SREBP-2、SREBPs裂解激活蛋白（SCAP）、蛋白聚糖（aggrecan）和Ⅱ型胶原（collagenⅡ）mRNA表达.结果 番红素O染色显示OA软骨组织表层粗糙,层次紊乱,染色变淡.OA组Mankin评分高于正常组（P＜0.01）.正常软骨抗SREBP-2免疫组化染色为阴性,而OA组为阳性.正常P2代软骨细胞collagenⅡ染色阳性、抗SREBP-2染色阴性;而经IL-1β刺激后X型胶原和SREBP-2染色阳性.WST-1检测IL-1β刺激组吸光度A值较对照组明显降低（P＜0.05）.PCR结果表明,各IL-1β组SREBP-2与SCAP mRNA的表达量均高于空白对照组,且随时间延长而升高,其中24 h组为（2.115±0.671）、（1.767 ±0.711）;48 h组为（2.367±0.530）、（2.910±0.398）;72 h组为（3.184 ±0.224）、（2.830±0.512） （P ＜0.05）,差异均有统计学意义.相反,各组中aggrecan、collagenⅡmRNA表达量随时间延长而降低,24 h组为（0.812±0.467）、（0.784±0.774）;48 h组为（0.529±0.439）、（0.626±1.100）;72 h组为（0.336±0.563）、（0.175±0.834） （P ＜0.05）,差异均具有统计学意义.结论 IL-1β能抑制正常软骨细胞增殖和软骨细胞基质成分的表达,并诱导其出现退行性改变.在诱导退变的过程中,SREBP-2的表达与软骨关键基因的表达呈负向变化关系.

英文摘要：

Objective To investigate the expression of sterol regulatory element-binding protein-2 （SREBP-2） in normal and osteoarthritis （OA） cartilage and chondrocyte.Method OA and normal knee cartilage were stained with safranin O and anti-SREBP-2 immunohistochemical staining and measured by Mankin score.Normal chondrocytes were randomly divided into control and interleukin （IL）-1β treated groups and the proliferation of chondrocytes was measured by WST-1 assay.Real-time reverse transcription PCR （RT-PCR） was used to detect the mRNA expression of SREBP-2,SREBP cleavage activating protein （SCAP）,aggrecan and collagen Ⅱ.Results OA cartilage surface was rough,disordered with weak staining in safranin O staining.OA cartilage showed a significantly higher Mankin score compared with normal cartilage （P 〈 0.05）.Normal cartilage had a negative anti-SREBP-2 staining,while a positive result was observed in OA cartilage.The second passage of normal chondrocytes was positive with anti-collagen Ⅱ and negative with anti-SREBP-2.Moreover,positive results of collagen X and anti-SREBP-2 staining were detected in the normal chondrocytes stimulated by IL-1β.WST-1 assay demonstrated that the absorbance （A） value was significantly decreased in the presence of IL-1β （P 〈 0.05）.RT-PCR indicated that the expression of SREBP-2 and SCAP was significantly increased （P 〈0.05） in IL-1β groups at 24 h（2.115 ±0.671）,（1.767 ±0.711）;48 h[（2.367 ±0.530）,（2.910 ±0.398）],and 72 h （3.184±0.224）,（2.830 ＆#177; 0.512）.On the other hand,the expression of aggrecan and collagen Ⅱ was considerably suppressed （P 〈 0.05） in IL-1β treated groups at 24 h （0.812 ± 0.467）,（0.784 ±0.774）;48 h（0.529 ±0.439）,（0.626 ± 1.100）,and 72 h （0.336 ±0.563）,（0.175 ±0.834）.Conclusion IL-1β inhibits the proliferation of normal chondrocyte and the expression of extracellular matrix,and also induces normal chondrocyte to degrade.A negative relationship is observed betw