Phospholipase C isoforms expression in mouse endothelium (1075.2)

Abstract

Phospholipase C (PLC) is a major signal transduction component through the regulation of various intracellular pathways, including PKC and intracellular Ca2+ channels. Up to 13 mammalian PLC isoforms have been identified and are classified in 6 families: PLC‐β, γ, δ, ε, ζ and η. Although expression of PLCs is tissue‐specific, combined expression of different PLCs has been reported. However, endothelial PLC expression remains to be established. Therefore, we sought to determine the expression pattern of PLC in mouse resistance arteries. We first studied the expression of PLC isoforms in mesenteric arteries. We found mRNA encoding for most PLCs with the exception of ζ1, η1 and η2 in whole mesenteric arteries. Similar results were obtained in middle cerebral, coronary and pulmonary arteries. We then elucidated the intracellular distribution of PLCs β3, γ1 and δ1, the main mammalian isoforms, in endothelial cells with in situ immunocytochemistry. We observed a diffuse staining in endothelium with no clearly defined heterogeneous distribution of all three PLCs. Further investigation is necessary to determine the specific PLC isoforms involved in endothelial localized Ca2+ dynamics. Taken together, these studies might strengthen our understanding of endothelial Ca2+ homeostasis mechanisms and therefore endothelial function.Grant Funding Source: Supported by FRQS, HSFC, SQHA and FICM.