Clostridium butyricum alleviates intestinal low-grade inflammation in TNBS-induced irritable bowel syndrome in mice by regulating functional status of lamina propria dendritic cells
Clostridium butyricum alleviates intestinal low-grade inflammation in TNBS-induced irritable bowel syndrome in mice by regulating functional status of lamina propria dendritic cells
复制标题
丁酸梭菌通过调节固有层树突状细胞的功能状态减轻 TNBS 诱导的肠易激综合征小鼠肠道低度炎症
DOI：
10.3748/wjg.v25.i36.5469
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发表时间：
2019
影响因子：
4.3
通讯作者：
Zuo Xiu-Li
中科院分区：
文献类型：
--
作者：
Zhao Qin;Yang Wen-Rong;Wang Xiao-Hong;Li Gai-Qin;Xu Lei-Qi;Cui Xiao;Liu Yang;Zuo Xiu-Li
背景肠易激综合征(IBS)是最常见的功能性胃肠病之一，其特点是内脏敏感性异常，炎症程度较轻。酪酸梭菌(Clostridium Butyricum)通过免疫途径减轻肠道低度炎症的作用已被明确。然而，丁酸杆菌对肠道粘膜免疫，特别是对固有层免疫细胞的影响机制尚不清楚。树突状细胞(DC)是一种重要的免疫细胞，能分泌促炎细胞因子(IL-1、β、IL-6等)，表达T细胞免疫球蛋白和粘蛋白结构域-3(TIM3)，促进DC的增殖和活化，并介导Th1和Th17炎性反应。目的探讨树突状细胞(DCs)在大鼠肠易激综合征(IBS)发病机制中的作用，了解丁酸链霉菌干预对DCs的调控作用。方法用C57BL/6小鼠建立IBS动物模型，连续灌胃给药，模拟不同的肠道免疫状态。分别用腹部撤退反射(AWR)试验和苏木精-伊红(H&E)染色评价肠道内脏超敏反应和组织病理学改变。用Western印迹分析和实时定量聚合酶链式反应分析促炎症细胞因子(IL-1、β、IL-6)和TIM3的表达。用流式细胞术分析固有层树突状细胞(LPDCs)的数量、功能和膜分子TIM3。通过体外实验验证了丁酸甘油对骨髓来源的树突状细胞的调节作用。结果肠易激综合征小鼠肠黏膜炎性细胞因子IL-1、β和IL-6的分泌较正常对照组显著增加，提示肠黏膜处于低度炎症状态。IBS小鼠肠道LPDCs中CD11c+CD80+和CD11c+TIM3+的表达显著增加。同时，经益生菌丁酸杆菌干预后，细胞因子(IL-1、β和IL-6)显著降低。随着肠道炎症反应的减轻，LPDCs的数量和功能减少，LPDCs表面TIM3的表达减少。结论丁酸葡萄球菌可调节IBS小鼠肠黏膜中LPDCs的数量和功能状态，从而调节肠道局部免疫反应。
BACKGROUND Irritable bowel syndrome (IBS) is one of the most common functional gas-troenterological diseases characterized by abnormal visceral sensitivity and low-grade inflammation. The role of Clostridium butyricum (C. butyricum) in reducing intestinal low-grade inflammation via immune pathways has been well defined. However, the detailed mechanisms of the effects of C. butyricum on intestinal mucosal immunity, especially on immune cells of the lamina propria, remain unclear. Dendritic cells (DCs), which are important immune cells, secrete proinflammatory cytokines (IL-1β, IL-6, and others) and express T cell immuno-globulin and mucin domain-3 (TIM3), promoting proliferation and activation of DCs, and mediating Th1 and Th17 inflammatory responses. AIM To investigate the role of DCs in the development of IBS in a rat model and to understand the regulation of DCs after C. butyricum intervention. METHODS An IBS animal model was established using C57BL/6 mice, and C. butyricum was continuously administered via the intragastric route to simulate different intestinal immune states. Intestinal visceral hypersensitivity and histopathology were assessed using the abdominal withdrawal reflex (AWR) test and hematoxylin & eosin (H&E) staining, respectively. The expression of proinflammatory cytokines (IL-1β and IL-6) and TIM3 was analyzed by Western blot analysis and real-time PCR. Flow cytometry was applied to analyze the quantity, function, and membrane molecule TIM3 of the lamina propria dendritic cells (LPDCs). The regulatory effect of C. butyricum was verified in bone marrow-derived dendritic cells by in vitro experiments. RESULTS The secretion of proinflammatory cytokines (IL-1β and IL-6) in mice with IBS was significantly increased compared with that of the control group, which suggested that the intestinal mucosa in mice with IBS was in a low-grade inflammatory state. The expression of CD11C+CD80+ and CD11c+TIM3+ in intestinal LPDCs in mice with IBS increased significantly. Meanwhile, the cytokines (IL-1β and IL-6) were significantly reduced after the intervention with probiotic C. butyricum. The amount and function of LPDCs and the TIM3 on the surface of the LPDCs were decreased with the alleviation of the intestinal inflammatory response. CONCLUSION The results suggest that C. butyricum regulates the amount and functional status of LPDCs in the intestinal mucosa of mice with IBS, and therefore modulates the local immune response in the intestine.