Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China.
Key Laboratory of Animal Nutrition and Feed Science (Hua Dong), Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
Life Sci. 2016 May 1;152:199-209. doi: 10.1016/j.lfs.2016.03.041. Epub 2016 Mar 24.
The present study examined the effect of the antimicrobial peptide cathelicidin-BF (CBF) on LPS-induced mucosal injury and intestinal epithelial barrier dysfunction in a rat model and in the porcine intestinal epithelial cell line.
Changes in barrier integrity were assessed in intestinal epithelium and IPEC-J2 monolayers by measuring nutrient absorption and transepithelial electrical resistance (TER), and the permeability of intestinal epithelium was examined by measuring plasma d-lactate and diamine oxidase levels. The expression levels of tight junction (TJ) proteins were quantified by real-time PCR, and immunofluorescence was used to analyse the location and distribution of TJs in cells.
In vivo, CBF improved epithelial barrier function through attenuating the alterations of the mucosal structure, nutrient absorption and TER in the jejunum, and preventing the down-regulation of TJ proteins in LPS-induced rat intestinal epithelium. In vitro, CBF prevented the disruption and the re-distribution of ZO-1 and occludin, and suppressed the increase in inflammatory cytokine levels in LPS-induced IPEC-J2. The CBF-induced upregulation of zonula occludens-1 and occludin was prevented by U0126 or SB203580, suggesting the involvement of the MEK and p38 MAPK pathways in the CBF-induced changes in tight junctions.
Our results showed that CBF prevents LPS-induced intestinal epithelial barrier dysfunction, suggesting its potential as a therapeutic agent for the prevention of LPS-mediated intestinal diseases. We found that exogenous CBF had protective effects on LPS-induced intestinal epithelial barrier disruption in rats and on epithelial damage in IPEC-J2 cells.
本研究旨在探讨抗菌肽 cathelicidin-BF (CBF) 对 LPS 诱导的黏膜损伤和肠上皮屏障功能障碍的影响，分别在大鼠模型和猪肠上皮细胞系中进行了研究。
通过测量营养物质吸收和跨上皮电阻（TER）来评估肠上皮和 IPEC-J2 单层中的屏障完整性变化，并通过测量血浆 d-乳酸和二胺氧化酶水平来检查肠上皮的通透性。通过实时 PCR 定量测定紧密连接（TJ）蛋白的表达水平，并通过免疫荧光分析细胞中 TJ 的位置和分布。
在体内，CBF 通过减轻 LPS 诱导的大鼠肠上皮中黏膜结构、营养物质吸收和 TER 的改变，以及防止 TJ 蛋白的下调，改善了上皮屏障功能。在体外，CBF 防止了 LPS 诱导的 IPEC-J2 中 ZO-1 和 occludin 的破坏和重新分布，并抑制了炎症细胞因子水平的升高。U0126 或 SB203580 可阻止 CBF 诱导的 zonula occludens-1 和 occludin 的上调，表明 MEK 和 p38 MAPK 途径参与了 CBF 诱导的 TJ 变化。
我们的结果表明，CBF 可防止 LPS 诱导的肠上皮屏障功能障碍，提示其作为预防 LPS 介导的肠道疾病的治疗剂的潜力。我们发现，外源性 CBF 对 LPS 诱导的大鼠肠上皮屏障破坏和 IPEC-J2 细胞上皮损伤具有保护作用。
