麩醯胺對DSS誘發急性腸炎小鼠免疫調節之影響

The immuno-regulatory effects of glutamine on dextran sulfate sodium-induced acute colitis in mice

朱嘉宙(Chia-Chou Chu)

指導教授 ： 趙振瑞

共同指導教授 ： 葉松鈴

臺北醫學大學/藥學院/藥學系(博士班)/博士(2011年)

https://doi.org/10.6831/TMU.2011.00073

摘要

本研究以dextran sulfate sodium (DSS) 誘發小鼠腸炎模式，探討於腸炎誘發前預防性投予，或腸炎後補充麩醯胺 (glutamine; Gln) 對調控輔助型T淋巴細胞 (helper T lymphocyte; Th) 與發炎反應之影響，並探討Gln之給予對於回復DSS誘發腸道損傷之機轉。以3 % DSS添加於C57BL/6小鼠飲水中連續5日誘發急性腸炎。實驗組給予Gln (0.5克/公斤體重) ，對照組給予等量不含Gln之胺基酸溶液或等體積之生理食鹽水 (saline) ，以腹腔注射方式介入，每日1次連續3日。預防性投予Gln實驗分為3組：(1) NC組－無誘發、無介入之正常控制組；(2) A-DSS組－誘發前給予不含Gln之等量胺基酸；(3) G-DSS組－誘發前給予Gln。腸炎後補充Gln實驗分為4組：(1) NC組－正常控制組；(2) S-DSS組－誘發前與後給予等體積saline；(3) G-DSS組－誘發前給予Gln，誘發後給予等體積之saline；(4) DSS-G組－誘發前給予等體積之saline，誘發後給予Gln。實驗結束後犧牲收集樣本進行分析。結果顯示，以DSS誘發腸炎會顯著提高血中haptoglobin濃度、Th17相關細胞激素表現、大腸沖洗液中巨噬細胞表現比率、腸繫膜淋巴結中interferon (IFN) -γ、interleukin (IL) -17A表現量、大腸中immunoglobin G、促發炎因子表現量以及myeloid peroxidase活性。給予Gln可降低血中Th17相關細胞激素表現比率及MLN內IFN-γ表現量，並降低大腸中IL-17A、toll-like receptor-4、keratinocyte-derived chemokine等基因表現，組織病理切片也顯示Gln給予組別之發炎指數評分顯著降低。於腸炎誘發前預防性投予Gln顯著增加大腸中mucin 2、trefoil factor 3、heat shock protein 72表現量，而誘發後補充Gln則可顯著提高B-cell lymphoma-extra large基因表現量。本研究結果顯示Gln在DSS誘發腸炎動物模式下可藉調節Th次群，降低發炎反應並減輕組織損傷，於誘發腸炎前預防性投予Gln可促進大腸黏膜修復，腸炎後補充Gln則有助於防止大腸黏膜細胞凋亡。

關鍵字

腸炎 ； 麩醯胺 ； dextran sulfate sodium ； T helper cells ； interleukin-17

並列摘要

Glutamine (Gln) is a nutrient with immune-modulatory effects. T helper lymphocytes (Th) play a major role in initiating and shaping the pathologic response in inflammatory bowel disease. This study investigated pretreated (preventive) or posttreated (replenished) effects of Gln on balance of Th subsets, anti-inflammatory responses and colitis recovery in dextran sulfate sodium (DSS)-induced colitis. DSS was dissolved in drinking water (3%, w/v) which was supplied to C57BL/6 mice for 5 days to induce colitis. Experimental groups were intraperitoneal injected with either Gln (0.5 g/ kg body weight), equal amount of amino acid solution excluding Gln or equal volume of saline for 3 days. In the experiment of preventive effects, there were 3 groups: (1) NC group: normal control without colitis and fed chow diet. (2) A-DSS group: colitis pre-treated with amino acid solution without Gln. (3) G-DSS group: colitis pre-treated with Gln. In the experiment of replenished effects, there were 4 groups: (1) NC group: normal control without colitis. (2) S-DSS group: administered saline before and after colitis. (3) G-DSS group: treated with Gln before colitis. (4) DSS-G group: treated with Gln after colitis. At the end of study, mice were sacrificed and samples were collected for further analysis. The results showed that DSS colitis resulted in higher percentages of blood Th17 related cytokines, Th-associated cytokines expressions in mesenteric lymphatic node (MLN) and pro-inflammatory factors expressions in colon tissue. Gln administration regulated blood Th17 related cytokine, MLN IFN-γ expressions and IL-17A, toll-like receptor 4, KC gene expressions in colon tissue. The inflammatory scores were lower in histological finding. Pretreated with Gln significantly increased mucin 2, trefoil factor 3 and heat shock protein 72 whereas administered Gln after the colitis enhanced B-cell lymphoma-extra large gene expressions. These results suggest that Gln administration balanced the Th subsets, reduced the inflammatory reaction and attenuated colon mucosal damage in DSS-induced colitis. Pretreatment with Gln may provide mucosal protection and healing while given Gln after the occurrence of colitis had anti-apoptotic effects of the colonic epithelial cells.

並列關鍵字

colitis ； dextran sulfate sodium ； glutamine ； T helper lymphocytes ； interleukin-17

參考文獻

Acosta-Rodriguez EV, Napolitani G, Lanzavecchia A and Sallusto F (2007) Interleukins 1beta and 6 but not transforming growth factor-beta are essential for the differentiation of interleukin 17-producing human T helper cells. Nat. Immunol. 8: 942-949.

Aharoni R, Kayhan B, Brenner O, Domev H, Labunskay G and Arnon R (2006) Immunomodulatory therapeutic effect of glatiramer acetate on several murine models of inflammatory bowel disease. J. Pharmacol. Exp. Ther. 318: 68-78.

Akahoshi T, Sasahara T, Namai R, Matsui T, Watabe H, Kitasato H, Inoue M and Kondo H (2003) Production of macrophage inflammatory protein 3alpha (MIP-3alpha) (CCL20) and MIP-3beta (CCL19) by human peripheral blood neutrophils in response to microbial pathogens. Infect. Immun. 71: 524-526.

Akobeng AK, Miller V, Stanton J, Elbadri AM and Thomas AG (2000) Double-blind randomized controlled trial of glutamine-enriched polymeric diet in the treatment of active Crohn's disease. J. Pediatr. Gastroenterol. Nutr. 30: 78-84.

Alex P, Zachos NC, Nguyen T, Gonzales L, Chen TE, Conklin LS, Centola M and Li X (2009) Distinct cytokine patterns identified from multiplex profiles of murine DSS and TNBS-induced colitis. Inflamm. Bowel Dis. 15: 341-352.