- 作者：Fang He ; Jing Peng ; Xiao-lu Deng ; Li-fen Yang ; Aboubacar Damayé ; Camara ; Ahmed Omran ; Guo-li Wang ; Li-wen Wu ; Ci-Liu Zhang ; Fei Yin ; yf23233@hotmail.com
- 关键词：Tumor necrosis factor-alpha ; Tight junction ; NF-魏B ; MLCK ; Permeability
- 刊名：Cytokine
- 出版年：2012
- 期刊代码：97_10434666
- 类别：imm
- 出版时间：August, 2012
- 卷：59
- 期：2
- 页码：264-272
- 文件大小：1375 K
Purpose
The aim of this study was to investigate the signaling mechanisms surrounding changes in tight junction (TJ) and the permeability of human intestinal epithelial cell induced by tumor necrosis factor-alpha (TNF-伪).Methods
To confirm that TNF-伪 induces epithelial barrier hyperpermeability by disrupting tight junction, Caco-2 cells were exposed to TNF-伪, and changes in epithelial permeability (via TER assay), F-actin dynamics (via Rhodamine-phalloidin staining) and tight junction protein expression (via western blot) were monitored. Moreover, to ensure that NF-魏B participated in the regulatory mechanisms, Caco-2 cells were transfected with DNMu-I魏B伪 or control plasmids, the above experiments were repeated and the activation effect of TNF-伪 on NF-魏B was detected by luciferase reporter assays. Lastly, we took dominant negative plasmid and knockdown approaches to investigate the potential importance of the NF-魏B/myosin light chain kinase (MLCK)/myosin light chain phosphorylation (pMLC) pathways in TNF-a-mediated damage.
Result
TNF-伪 could cause NF-魏B activation, F-actin rearrangement, tight junction disruption and barrier dysfunction. These effects were alleviated by inhibiting NF-魏B. TNF-伪 induced increase of MLCK transcription and MLC phosphorylation act later than NF-魏B activation, which could be suppressed both by inactivating and deleting NF-魏B.
Conclusions
TNF-伪 induces intestinal epithelial cell hyperpermeability by disrupting TJs, in part through MLCK upregulation, in which NF-魏B is the positive upstream regulator for MLCK.