Adenovirus vector E4 gene regulates connexin 40 and 43 expression in endothelial cells via PKA and PI3K signal pathways.

Publication Type	Academic Article
Authors	Zhang F, Cheng J, Lam G, Jin D, Vincent L, Hackett N, Wang S, Young L, Hempstead B, Crystal R, Rafii S
Journal	Circ Res
Volume	96
Issue	9
Pagination	950-7
Date Published	04/14/2005
ISSN	1524-4571
Keywords	Adenoviridae, Adenovirus E4 Proteins, Connexin 43, Connexins, Cyclic AMP-Dependent Protein Kinases, Endothelium, Vascular, Phosphatidylinositol 3-Kinases
Abstract	Connexins (Cxs) provide a means for intercellular communication and play important roles in the pathophysiology of vascular cardiac diseases. Infection of endothelial cells (ECs) with first-generation E1/E3-deleted E4+ adenovirus (AdE4+) selectively modulates the survival and angiogenic potential of ECs by as of yet unrecognized mechanisms. We show here that AdE4+ vectors potentiate Cx expression in ECs in vitro and in mouse heart tissue. Infection of ECs with AdE4+, but not AdE4-, resulted in a time- and dose-dependent induction of junctional Cx40 expression and suppression of Cx43 protein and mRNA expression. Treatment of ECs with PKA inhibitor H89 or PI3K inhibitor LY294002 prevented the AdE4+-mediated regulation of Cx40 and Cx43 that was associated with diminished AdE4+-mediated survival of ECs. Moreover, both PKA activity and cAMP-response element (CRE)-binding activity were enhanced by treatment of ECs with AdE4+. However, there is no causal evidence of a cross-talk between the 2 modulatory pathways, PKA and PI3K. Remarkably, Cx40 immunostaining was markedly increased and Cx43 was decreased in the heart tissue of mice treated with intra-tracheal AdE4+. Taken together, these results suggest that AdE4+ may play an important role in the regulation of Cx expression in ECs, and that these effects are mediated by both the PKA/CREB and PI3K signaling pathways.
DOI	10.1161/01.RES.0000165867.95291.7b
PubMed ID	15831817
PubMed Central ID	PMC2935198