热休克蛋白65对小鼠溃疡性结肠炎的作用机制研究*

Therapeutic effect of heat shock protein 65 on ulcerative colitis in mice*

摘要:

目的 探讨热休克蛋白65（HSP65）对小鼠溃疡性结肠炎（UC）的作用及机制。方法 选择C57BL/6小鼠，应用葡聚糖硫酸钠法复制UC模型。6只正常小鼠为正常对照组（A组），48只UC小鼠随机分成模型对照组（B组）、低剂量组（C组）、中剂量组（D组）及高剂量组（E组），每组12只。A组和B组小鼠灌胃给予磷酸盐缓冲液（PBS），C组、D组、E组小鼠分别灌胃给予HSP65，剂量分别是0.5、2.5及5.0?mg/kg体重。隔天灌胃1次，共7次，末次灌胃2?d后，麻醉处死小鼠。计算小鼠疾病活动指数（DAI）。取小鼠结肠中段组织，HE染色镜检并计算组织病理评分。取小鼠血液、脾脏和肠系膜淋巴结，分离有核细胞后采用流式细胞术检测调节性T细胞（Treg）活化情况。结果 HSP65蛋白治疗UC小鼠14?d，B、C、D及E组小鼠的DAI分别为（3.66±0.39）、（3.07±0.15）、（1.50±0.43）和（0.83±0.31），C组、D组、E组小鼠DAI变化趋势有差异（P?<0.05）；C组、D组和E组小鼠结肠组织病理评分均低于B组小鼠（P?<0.05）；E组小鼠结肠组织病理评分低于C组和D组（P?<0.05），D组小鼠结肠组织病理评分低于C组（P?<0.05）；与未治疗的B组比较，C组、D组、E组小鼠肠系膜淋巴结中的Treg细胞比例均高于B组（P?<0.05）。结论 HSP65蛋白可以缓解小鼠溃疡性结肠炎，其机制可能是通过激活小鼠肠系膜淋巴结中的静止Treg细胞，使得活化Treg细胞比例增加，再通过活化Treg细胞发挥抑制肠道炎症反应作用。

Abstract:

Objective To investigate the therapeutic effect and mechanism of heat shock protein 65 (HSP 65) on ulcerative colitis (UC) in mice. Methods UC disease model was established in C57BL/6 mice by dextran sulphate sodium salt (DSS). UC mice were randomly divided into model control group (group B), low-dose group (group C), medium dose group (group D) and high-dose group (group E). Mice in group C, group D and group E were respectively given 0.5?mg, 2.5?mg and 5.0?mg HSP 65 protein/kg body weight, respectively (once every other day for 7 times by gavage). Mice in normal control group (group A) and model control group (group B) received PBS solution by gavage. The mice were anesthetized and executed 2 days after the last gavage. The disease activity index (DAI) of mice in each group were analyzed. The histopathological score of colons (HSC) were examined by HE staining. After the nuclear cells were isolated from blood, spleen and mesenteric lymph nodes, the ratio of activated regulatory T cells (Treg) was detected by flow cytometry. Results DAI of mice in group B, group C, group D and group E were (3.66?±?0.39), (3.07?±?0.15), (1.50?±?0.43) and (0.83?±?0.31), respectively. DAI was decreased with treatment of HSP 65 in dose dependent manner (P?