黄芪杂多糖对佐剂性关节炎大鼠促炎因子分泌及关节滑膜细胞凋亡的调节作用

Regulation of Astragalus heteropolysaccharides on synoviocytes apoptosis and proinflammatory cytokine secretion of rats with adjuvant arthritis

建立大鼠佐剂性关节炎(AA)模型,研究黄芪杂多糖(AHPS)对佐剂性关节炎大鼠促炎因子分泌及关节滑膜细胞凋亡的调节作用。采用常规病理组织学检查大鼠膝关节滑膜,放射免疫法测定血清中IL-1β和TNF-α的含量,Tunel检测滑膜细胞凋亡,免疫组化检测Bcl-2、Bax表达,并进行足爪容积测定和关节炎症评分。结果显示:AHPS和雷公藤多苷(TWP)均能显著改善AA大鼠原发和继发性临床症状及关节滑膜炎的炎性变化;AHPS(1 000和500 mg.kg-1)及TWP(60 mg.kg-1)可使AA大鼠的血清TNF-α、IL-1β水平显著降低(P<0.01或P<0.05),并可使AA大鼠的膝关节滑膜细胞凋亡数量显著升高(P<0.01或P<0.05);AA大鼠的Bax阳性表达率有所升高(P>0.05),Bcl-2阳性表达率升高显著(P<0.01),而AHPS(1 000和500 mg.kg-1)可显著下调AA大鼠膝关节滑膜Bcl-2的阳性表达和上调Bax的阳性表达(P<0.01或P<0.05)。结果表明:AHPS诱导AA大鼠膝关节滑膜细胞凋亡的作用与下调Bcl-2和上调Bax蛋白表达有关,抑制促炎因子分泌是其抗炎症作用的分子机制之一。

This study is to observe anti-inflammation mechanism of Astragalus heteropolysaccharides （AHPS） on rats with adjuvant arthritis （AA）. Rats were treated with AHPS （1 000, 500, and 250 mg.kg^-1, ig） and Tripterygium wilfordii polyglycoside （TWP, 60 mg.kg^-1, ig）, separately. TNF-α and IL-1β contents in serum were determined with radioimmunoassay, pathomorphologic changes of synovium of knee joint were observed by histological section with HE staining, synoviocyte apoptosis of knee joint of rats was analyzed by Tunel detection, and Bax and Bcl-2 positive expression were detected by immunohistochemical method. The results were as follows： （1） both AHPS and TWP could improve significantly primary and secondary clinical symptoms of rats with AA and inflammatory response in articular synovium; （2） the contents of TNF-α and IL-1β in serum of rats with AA increased significantly composed with those in groups treated with AHPS （1 000 and 500 mg.kg^-1）, and the amount of synoviocyte apoptosis decreased significantly （P 〈 0.01 or P 〈 0.05）; （3） the positive expression of Bax in synovium of rats with AA was a little bit higher than that in normal control （P 〉 0.05）, but the positive expression of Bcl-2 significantly increased （P 〈 0.01）. AHPS （1 000 and 500 mg.kg^-1） could up-regulate positive expression of Bax and down-regulate the positive expression of Bcl-2 significantly （P 〈 0.05 or P 〈 0.01）. The results show that AHPS can evidently decrease TNF-α and IL-1β level in serum of rats with AA, which is one of molecular mechanisms that AHPS has anti-inflammatory properties. AHPS can induce synoviocyte apoptosis of rats with AA, which is achieved by the regulating effect of AHPS on the positive expression of Bax and Bcl-2.