1. Suppressing PTEN activity by tobacco smoke plus interleukin-1beta modulates dissociation of VE-cadherin/beta-catenin complexes in endothelium.
- Author
-
Barbieri SS, Ruggiero L, Tremoli E, and Weksler BB
- Subjects
- Adherens Junctions drug effects, Adherens Junctions metabolism, Animals, Antigens, CD chemistry, Apolipoproteins E deficiency, Apolipoproteins E genetics, Atherosclerosis etiology, Atherosclerosis metabolism, Cadherins chemistry, Mice, Mice, Knockout, Multiprotein Complexes, Smoking adverse effects, beta Catenin chemistry, Antigens, CD metabolism, Cadherins metabolism, Endothelium, Vascular drug effects, Endothelium, Vascular metabolism, Interleukin-1beta pharmacology, PTEN Phosphohydrolase antagonists & inhibitors, Smoke adverse effects, Nicotiana toxicity, beta Catenin metabolism
- Abstract
Objective: Tobacco smoke (TS) interacts with inflammatory cytokines to produce endothelial dysfunction. We hypothesized that interleukin-1beta (IL-1beta) plus TS (TS/IL-1beta) induces disassembly of endothelial junctional complexes of VE-cadherin/beta-catenin by suppression of PTEN activity and investigated molecular mechanisms that modulate PTEN-deactivation in this situation., Methods and Results: TS/IL-1beta exposure, which disrupted adherens junctions and induced nuclear beta-catenin accumulation, increased tyrosine phosphorylation (p-Tyr) of VE-cadherin and beta-catenin, and reduced PTEN activity. Overexpression or silencing of PTEN modulated p-Tyr of both VE-cadherin and beta-catenin, changed assembly of adherens junction complexes, and altered nuclear beta-catenin accumulation. In addition, inhibiting ROS production stimulated by TS/IL-1beta decreased activation of Src, EGFR and p38MAPK, phosphorylation of PTEN, VE-cadherin and beta-catenin, and abrogated the effect of TS/IL-1beta to disorganize adherens junctions, resulting in reduced endothelial permeability and decreased nuclear beta-catenin accumulation. Finally, exposure of ApoE(-/-) mice to cigarette smoke-induced phosphorylation of Src, EGFR, p-38MAPK, PTEN, and beta-catenin, and disrupted VE-cadherin/beta-catenin complexes in cardiovascular tissue., Conclusions: TS interaction with IL-1beta modulates PTEN activity though the ROS/Src/EGFR-p38MAPK pathway. PTEN deactivation is essential to increase VE-cadherin and beta-catenin p-Tyr and to disassemble VE-cadherin/beta-catenin membrane complexes, events that lead to accumulation of beta-catenin within the nucleus.
- Published
- 2008
- Full Text
- View/download PDF