Probiotics inhibit nuclear factor-κB and induce heat shock proteins in colonic epithelial cells through proteasome inhibition
Probiotics inhibit nuclear factor-κB and induce heat shock proteins in colonic epithelial cells through proteasome inhibition
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DOI：
10.1053/j.gastro.2004.09.001
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发表时间：
2004-11-01
期刊：
影响因子：
29.4
通讯作者：
Chang, EB
中科院分区：
文献类型：
--
作者：
Petrof, EO;Kojima, K;Chang, EB
背景与目的：炎症性肠病黏膜损伤的程度和严重程度取决于两个对立的过程之间的失衡：修复和细胞保护机制与炎症诱导的损伤。益生菌可能通过改善结肠炎而提供临床益处；然而，它们的作用机制在很大程度上仍不清楚。我们的目标是研究微生物-上皮细胞的相互作用，以解释益生菌的有益治疗效果。方法：采用单核细胞趋化蛋白-1酶联免疫吸附试验、IkappaBalpha、IkappaBβ和p105免疫印迹分析、核因子-kappaB荧光素酶报告基因和蛋白酶体分析等方法，观察VSL#3条件培养液对幼年小鼠结肠上皮细胞核因子-kappaB途径的影响。用凝胶电泳法和免疫印迹法检测幼年小鼠结肠细胞中热休克蛋白25和72对热休克蛋白的影响。氧化损伤的细胞保护作用通过铬51释放和丝状和球状肌动蛋白测定来确定。结果：VSL#3产生的可溶性因子抑制了肠上皮细胞中蛋白酶体的凝乳酶样活性。蛋白酶体抑制是一种早期事件，几乎是在上皮细胞接触益生菌条件培养液后立即开始的。此外，这些细菌通过一种不同于其他非致病肠道菌群所描述的III型分泌机制的机制来抑制前炎症核因子-kappaB途径。它们还诱导肠上皮细胞表达细胞保护性热休克蛋白。结论：核因子-kappaB的抑制和热休克蛋白表达的增加可能是益生菌的抗炎和细胞保护作用的原因，也可能是微生物-上皮相互作用的新机制。这些作用似乎是通过蛋白酶体抑制这一共同的统一机制来实现的。
Background & Aims: The extent and severity of mucosal injury in inflammatory bowel diseases are determined by the disequilibrium between 2 opposing processes: reparative and cytoprotective mechanisms vs. inflammation-induced injury. Probiotics may provide clinical benefit by ameliorating colitis; however, their mechanisms of action remain largely unknown. Our objective was to investigate microbial-epithelial interactions that could explain the beneficial therapeutic effects of probiotics. Methods: The effect of VSL#3-conditioned media on the nuclear factor-kappaB pathway in young adult mouse colonic epithelial cells was assessed by using monocyte chemoattractant protein-1 enzyme-linked immunosorbent assays; IkappaBalpha, IkappaBbeta, and p105 immunoblot analysis; and nuclear factor-kappaB luciferase reporter gene and proteasome assays. Effects on heat shock proteins were determined by electrophoretic mobility shift assay and immunoblot for heat shock proteins 25 and 72 in young adult mouse colonic cells. Cytoprotection against oxidant injury was determined by chromium 51 release and filamentous and globular actin assays. Results: VSL#3 produces soluble factors that inhibit the chymotrypsin-like activity of the proteasome in gut epithelial cells. Proteasome inhibition is an early event that begins almost immediately after exposure of the epithelial cells to the probiotic-conditioned media. In addition, these bacteria inhibit the proinflammatory nuclear factor-kappaB pathway through a mechanism different from the type III secretory mechanisms described for other nonpathogenic enteric flora. They also induce the expression of cytoprotective heat shock proteins in intestinal epithelial cells. Conclusions: The resulting inhibition of nuclear factor-kappaB and increased expression of heat shock proteins may account for the anti-inflammatory and cytoprotective effects reported for probiotics and may be a novel mechanism of microbial-epithelial interaction. These effects seem to be mediated through the common unifying mechanism of proteasome inhibition.