title: PKC and RhoA signals cross-talk in Escherichia coli endotoxin induced alterations in brain endothelial permeability.
abstract: Escherichia coli endotoxin LPS regulates blood-brain barrier permeability by disrupting the tight junction (TJ) complex between brain endothelial cells. This study used Bend.3 cells to examine the signaling networks involved in the hyperpermeability of the brain endothelial barrier caused by LPS. The LPS-induced alterations in the brain endothelial barrier were associated with PKC (a, β, ζ) and RhoA, but were independent of PI3K and the tyrosine kinase pathway. Inhibition of PKC (a, β, ζ) and RhoA activity using shRNA and dominant negative mutants diminished the effects of LPS on the brain's endothelial TJs. The interactions between the PKC and Rho pathways were therefore examined. PKC-a and PKC-ζ, but not PKC-β interacted with RhoA in Bend.3 cells stimulated by LPS. PKC-a acted as the upstream molecule for Rho and PKC-ζ acted as the downstream target for Rho. Comparing the effect of double inhibition of "Rho and PKC" and single inhibition of "Rho" or "PKC" confirmed that this interaction is critical for LPS-induced brain endothelial cell hyperpermeability. Collectively these data are the first to suggest that LPS affects the brain's endothelial TJ barrier via PKC (a, β, ζ)- and RhoA, independent of the PI3K and tyrosine kinase pathways. In addition, PKC-a and PKC-ζ, respectively, act as the upstream and downstream regulator for RhoA in the process.
authors: Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan 41008, China.
authors: Fang
authors: F
authors: He
authors: Fei
authors: F
authors: Yin
authors: Ahmed
authors: A
authors: Omran
authors: Li-fen
authors: LF
authors: Yang
authors: Qiu-lian
authors: QL
authors: Xiang
authors: Jing
authors: J
authors: Peng
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism*; D002460:Cell Line; D004727:Endothelium / Q000378:metabolism; D004731:Endotoxins / Q000378:metabolism*; D051379:Mice; D010539:Permeability; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction; D014162:Transfection; D020742:rhoA GTP-Binding Protein / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D004731:Endotoxins; D034741:RNA, Small Interfering; C044101:endotoxin, Escherichia coli; D011493:Protein Kinase C; D020742:rhoA GTP-Binding Protein