TNF-α对兔软骨终板细胞增殖、凋亡及基质形成的影响

目的：探讨TNF-α对体外培养的兔软骨终板细胞增殖、凋亡及基质形成的影响。方法:分离培养并鉴定兔软骨终板细胞后，分别加入不同浓度的TNF-α，用 MTT测定不同时点软骨终板细胞增殖活性的变化；免疫组化法检测Bcl-2、Bax、Fas、caspase-3 表达的变化；RT-PCR 检测培养过程中蛋白聚糖、Ⅱ型胶原 mRNA 的表达变化。结果:50 μg/L、100 μg/L浓度TNF-α可抑制细胞增殖；50 μg/L浓度TNF-α可降低 Bcl-2的表达，10 μg/L、50 μg/L浓度TNF-α均可促进Bax、Fas、caspase-3 的表达；10 μg/L、50 μg/L浓度TNF-α可降低collagen IIa mRNA 的表达，TNF-α 为50 μg/L浓度时才可降低aggrecan mRNA 的表达。结论:TNF-α可抑制软骨终板细胞的增殖及基质合成，促进软骨终板细胞促凋亡因子的生成。

Effect of TNF-α on the cartilage endplate chondrocytes of New Zealand white rabbits

AIM:To evaluate the biological roles of TNF-α on the cartilage endplate cells (chondrocytes). METHODS:The chondrocytes were isolated and harvested from the cartilage endplate of New Zealand rabbits and then the biological characteristics of cells were identified by methods such as toluidine blue staining for type Ⅱ collagen. After different concentrations of TNF-α were added to culture medium respectively, the rate of the proliferation of chondrocytes in different time was measured with MTT. The protein expressions of Bax, Bcl-2, Fas and caspase-3 were measured by immunocytochemistry. The changes of the mRNA of aggrecan and type Ⅱ collagen were measured by RT-PCR. RESULTS:The TNF-α at concentration of 50 μg/L and 100 μg/L decreased the rate of the proliferation on chondrocytes. Though TNF-α at concentrations of 10 μg/L and 50 μg/L increased the level of Bax, Fas and caspase-3, only 50 μg/L TNF-α decreased the level of Bcl-2. TNF-α at concentrations of 10 μg/L and 50 μg/L decreased the level of collagen IIa mRNA and only 50 μg/L TNF-α decreased the level of aggrecan. CONCLUSION:TNF-α not only inhibits the proliferation and the matrix synthesis in chondrocytes, but also increases the expression of pro-apoptotic factors in chondrocytes.