Eun Chang Soo, Han Dong Soo, Lee Seung Hyun, Jeon Yong Cheol, Sohn Joo Hyun, Kim Yong Seok, Lee Jin
Department of Internal Medicine, Hanyang University College of Medicine, Guri Hospital, 249-1 Gyomun-dong, Guri, Korea.
Korean J Gastroenterol. 2007 Mar;49(3):139-46.
BACKGROUND/AIMS: The peroxisome proliferator-activated receptor gamma (PPARgamma) is a nuclear receptor highly expressed in the colon which plays an anti-inflammatory role through the inhibition of nuclear factor-kappaB (NF-kappaB) pathway. Probiotics have been shown to exert beneficial effects on inflammatory bowel diseases. However, the exact mechanism by which probiotics exert protection against intestinal inflammation is not well understood. The aims of this study were to evaluate the attenuation of inflammatory response by probiotics in intestinal epithelial cells and to study the association between probiotics and PPARgamma.
HT-29 human epithelial cells were stimulated with LPS (20 microg/mL) and probiotics, Lactobacillus casei (L. casei) (10(5)-10(7) cfu/mL), or with LPS (20 microg/mL) alone for 24 hours. Interleukin-8 (IL-8), cyclooxygenase-2 (COX-2), toll-like receptor-4 (TLR-4) and PPARgamma mRNA expressions were assessed by RT-PCR. IL-8 protein secretion was measured by ELISA. HT-29 cells were transfected with tk promoter-luciferase plasmid containing a peroxisome proliferator response element (PPRE). After stimulation with L. casei or PPARgamma agonist (15d-PGJ2 or ciglitazone), luciferase activities were measured.
LPS induced IL-8, COX-2, TLR-4 mRNA expression, and IL-8 protein secretion in HT-29 cells. Treatment with LPS and L. casei in comparison with LPS stimulation alone lowered IL-8, COX-2, TLR-4 mRNA expression, and IL-8 protein secretion. L. casei increased PPARgamma mRNA expression in dose-dependent manner. L. casei activated PPRE in HT-29 cells transfected with PPRE3-tk-luciferase construct.
Probiotics, L. casei, suppresses the expression of inflammatory mediators in intestinal epithelial cells. The anti-inflammatory action of L. casei might be partially related to PPARgamma activation.
背景/目的：过氧化物酶体增殖物激活受体γ（PPARγ）是一种在结肠中高度表达的核受体，其通过抑制核因子κB（NF-κB）途径发挥抗炎作用。益生菌已被证明对炎症性肠病具有有益作用。然而，益生菌发挥肠道炎症保护作用的确切机制尚不清楚。本研究的目的是评估益生菌对肠上皮细胞炎症反应的减轻作用，并研究益生菌与PPARγ之间的关联。
用脂多糖（LPS，20μg/mL）和益生菌干酪乳杆菌（L. casei，10⁵-10⁷cfu/mL）刺激HT-29人上皮细胞24小时，或仅用LPS（20μg/mL）刺激24小时。通过逆转录-聚合酶链反应（RT-PCR）评估白细胞介素-8（IL-8）、环氧化酶-2（COX-2）、Toll样受体4（TLR-4）和PPARγmRNA的表达。通过酶联免疫吸附测定（ELISA）测量IL-8蛋白分泌。用含有过氧化物酶体增殖物反应元件（PPRE）的tk启动子-荧光素酶质粒转染HT-29细胞。在用干酪乳杆菌或PPARγ激动剂（15d-PGJ2或吡格列酮）刺激后，测量荧光素酶活性。
LPS诱导HT-29细胞中IL-8、COX-2、TLR-4 mRNA表达以及IL-8蛋白分泌。与单独的LPS刺激相比，用LPS和干酪乳杆菌处理降低了IL-8、COX-2、TLR-4 mRNA表达以及IL-8蛋白分泌。干酪乳杆菌以剂量依赖方式增加PPARγmRNA表达。干酪乳杆菌激活了用PPRE3-tk-荧光素酶构建体转染的HT-29细胞中的PPRE。
益生菌干酪乳杆菌抑制肠上皮细胞中炎症介质的表达。干酪乳杆菌的抗炎作用可能部分与PPARγ激活有关。
