吡格列酮对噁唑酮诱导的小鼠实验性结肠炎模型的影响

Effect of pioglitazone on oxazolone-induced colitis in mice

目的 观察吡格列酮对唑酮结肠炎的干预 ,探讨其是否通过Fas Fas配体 (FasL)途径促进细胞凋亡参与免疫调节作用。方法 经唑酮诱导成功的BALb/c小鼠 ,每组 6只 ,第 1组于灌肠后3d分离结肠固有层单个核细胞 (LPMC) ,并在体外用吡格列酮 (40 μmol/L)处理 2 4h ,采用annexin V FITC试验法分析凋亡细胞的百分率 ,采用流式细胞术检测Fas及FasL表达 ;并没未处理的正常小鼠组。第 2组 (对照组 )和第 3组 (实验组 )于灌肠后 3d分别给予二甲基纤维素和吡格列酮 (2 0mg·kg-1·d-1)连续 7d ,结肠炎症的评价包括炎症活动指数 (DAI)、大体形态损伤、组织学改变及肠黏膜髓过氧化物酶 (MPO)活性 ,采用ELISA法检测白细胞介素 (IL) 4和IL 5。结果 正常小鼠和结肠炎小鼠结肠组织LPMC凋亡率、Fas、FasL表达分别为 12 .89± 1.2 3、70 .6 3± 6 .2 4、8.5 9± 5 .4 7和 4 .2 5± 0 .84、6 2 .6 0±5 .85、2 3.75± 10 .2 3;经吡格列酮处理后 ,分别为 4 0 .5 8± 10 .32、83.98± 11.38、10 .0 4± 5 .2 1。对照组和实验组大体形态、组织学损伤、MPO值、IL 4、IL 5分别为 2 .5 0± 0 .5 5、8.83± 0 .75、3.81± 0 .17、2 16 .4 6± 34.32、10 2 .2 8± 2 5 .74和 0 .33± 0 .5 2、4 .0 0± 0 .6 3、1.2 5± 0 .16。

Objective To investigate the effect of pioglitazone on oxazolone-induced colitis and to clarify the mechanism of apoptosis by Fas/Fas ligand(FasL). Methods Eighteen BALb/c mice of ulcerative colitis induced by oxazolone enema were equally allocated into 3 groups. The mice in group 1 were sacrificed 3 days after enema,lamina propria mononuclear cells(LPMC) were isolated from freshly obtained colonic specimens and treated in vitro with pioglitazone (40 μmol/L),the annexin-V-FITC was used for detection of apoptosis,and Fas/FasL expression was assayed by flow cytometry. Meanwhile,untreated mice were served as normal controls. Mice in group 2 (control group) and 3 (experiment group) were treated with methylcellulose or pioglitazone(20 mg·kg -1 ·d -1 ) 3 days after enema and were administrated for consecutive 7 days. The colonic inflammation including disease activity index (DAI),macroscopic and histological changes,myeloperoxidase(MPO) activity and levels of interleukin (IL)-4,IL-5 were evaluated. Results Apoptosis of LPMC,expression of Fas and FasL in normal and colitis mucosa were 12.89±1.23,70.63±6.24,8.59±5.47 and 4.25±0.84,62.60±5.85,23.75±10.23,respectively. After treated with pioglitazone,both apoptosis of LPMC and expression of Fas increased,while FasL expression decreased (40.58±10.32,83.98±11.38 and 10.04±5.21 respectively). In group 2 and group 3,the macroscopic and microscopic score,MPO activity,IL-4 and IL-5 level were 2.50±0.55,8.83±0.75, 3.81±0.17,216.46±34.32,102.28±25.74 and 0.33 ±0.52,4.00±0.63,1.25±0.16,179.36±18.15,61.65±17.45,respectively. Conclusion The results indicate that pioglitazone treatment can significantly attenuate colonic inflammation,and it might be related to the apoptosis of LPMC through Fas and FasL.