Involvement of PKCα-MAPK/ERK-phospholipase A(2) pathway in the Escherichia coli invasion of brain microvascular endothelial cells.

Escherichia coli K1 is the most common Gram-negative organism that causes neonatal meningitis following penetration of the blood-brain barrier. In the present study we demonstrated the involvement of cytosolic (cPLA(2)) and calcium-independent phospholipase A(2) (iPLA(2)) and the contribution of cyclooxygenase-2 products in E. coli invasion of microvascular endothelial cells. The traversal of bacteria did not determine trans-endothelial electrical resistance (TEER) and ZO-1 expression changes and was reduced by PLA(2)s siRNA. cPLA(2) and iPLA(2) enzyme activities and cPLA(2) phosphorylation were stimulated after E. coli incubation and were attenuated by PLA(2), PI3-K, ERK 1/2 inhibitors. Our results demonstrate the role of PKCα/ERK/MAPK signaling pathways in governing the E. coli penetration into the brain.