First Author | Gao XP | Year | 2007 |
Journal | J Biol Chem | Volume | 282 |
Issue | 9 | Pages | 6116-25 |
PubMed ID | 17197441 | Mgi Jnum | J:120880 |
Mgi Id | MGI:3708202 | Doi | 10.1074/jbc.M610248200 |
Citation | Gao XP, et al. (2007) Blockade of class IA phosphoinositide 3-kinase in neutrophils prevents NADPH oxidase activation- and adhesion-dependent inflammation. J Biol Chem 282(9):6116-25 |
abstractText | We examined the role of class IA phosphoinositide 3-kinase (PI3K) in the regulation of activation of NADPH oxidase in PMNs and the mechanism of PMN-dependent lung inflammation and microvessel injury induced by the pro-inflammatory cytokine TNF-alpha. TNF-alpha stimulation of PMNs resulted in superoxide production that was dependent on CD11b/CD18-mediated PMN adhesion. Additionally, TNF-alpha induced the association of CD11b/CD18 with the NADPH oxidase subunit Nox2 (gp91(phox)) and phosphorylation of p47(phox), indicating the CD11b/CD18 dependence of NADPH oxidase activation. Transduction of wild-type PMNs with Deltap85 protein, a dominant-negative form of the class IA PI3K regulatory subunit, p85alpha, fused to HIV-TAT (TAT-Deltap85) prevented (i) CD11b/CD18-dependent PMN adhesion, (ii) interaction of CD11b/CD18 with Nox2 and phosphorylation of p47(phox), and (iii) PMN oxidant production. Furthermore, studies in mice showed that i.v. infusion of TAT-Deltap85 significantly reduced the recruitment of PMNs in lungs and increase in lung microvascular permeability induced by TNF-alpha. We conclude that class IA PI3K serves as a nodal point regulating CD11b/CD18-integrin-dependent PMN adhesion and activation of NADPH oxidase, and leads to oxidant production at sites of PMN adhesion, and the resultant lung microvascular injury in mice. |