title: Expression of phosphoinositide-specific phospholipase C isoforms in native endothelial cells.
abstract: Phospholipase C (PLC) comprises a superfamily of enzymes that play a key role in a wide array of intracellular signalling pathways, including protein kinase C and intracellular calcium. Thirteen different mammalian PLC isoforms have been identified and classified into 6 families (PLC-β, γ, δ, ε, ζ and η) based on their biochemical properties. Although the expression of PLC isoforms is tissue-specific, concomitant expression of different PLC has been reported, suggesting that PLC family is involved in multiple cellular functions. Despite their critical role, the PLC isoforms expressed in native endothelial cells (ECs) remains undetermined. A conventional PCR approach was initially used to elucidate the mRNA expression pattern of PLC isoforms in 3 distinct murine vascular beds: mesenteric (MA), pulmonary (PA) and middle cerebral arteries (MCA). mRNA encoding for most PLC isoforms was detected in MA, MCA and PA with the exception of η2 and β2 (only expressed in PA), δ4 (only expressed in MCA), η1 (expressed in all but MA) and ζ (not detected in any vascular beds tested). The endothelial-specific PLC expression was then sought in freshly isolated ECs. Interestingly, the PLC expression profile appears to differ across the investigated arterial beds. While mRNA for 8 of the 13 PLC isoforms was detected in ECs from MA, two additional PLC isoforms were detected in ECs from PA and MCA. Co-expression of multiple PLC isoforms in ECs suggests an elaborate network of signalling pathways: PLC isoforms may contribute to the complexity or diversity of signalling by their selective localization in cellular microdomains. However in situ immunofluorescence revealed a homogeneous distribution for all PLC isoforms probed (β3, γ2 and δ1) in intact endothelium. Although PLC isoforms play a crucial role in endothelial signal transduction, subcellular localization alone does not appear to be sufficient to determine the role of PLC in the signalling microdomains found in the native endothelium.
authors: Research Center, Montreal Heart Institute, Montreal, Qc, Canada; Department of Molecular and Integrative Physiology, Université de Montréal, Montreal, Qc, Canada.
authors: Delphine M
authors: DM
authors: Béziau
authors: Research Center, Montreal Heart Institute, Montreal, Qc, Canada; Department of Molecular and Integrative Physiology, Université de Montréal, Montreal, Qc, Canada.
authors: Fanny
authors: F
authors: Toussaint
authors: Research Center, Montreal Heart Institute, Montreal, Qc, Canada.
authors: Alexandre
authors: A
authors: Blanchette
authors: Research Center, Montreal Heart Institute, Montreal, Qc, Canada; Department of Medicine, Université de Montréal, Montreal, Qc, Canada.
authors: Nour R
authors: NR
authors: Dayeh
authors: Research Center, Montreal Heart Institute, Montreal, Qc, Canada; Department of Pharmacology, Université de Montréal, Montreal, Qc, Canada.
authors: Chimène
authors: C
authors: Charbel
authors: Research Center, Montreal Heart Institute, Montreal, Qc, Canada; Department of Medicine, Université de Montréal, Montreal, Qc, Canada.
authors: Jean-Claude
authors: JC
authors: Tardif
authors: Research Center, Montreal Heart Institute, Montreal, Qc, Canada; Department of Medicine, Université de Montréal, Montreal, Qc, Canada.
authors: Jocelyn
authors: J
authors: Dupuis
authors: Research Center, Montreal Heart Institute, Montreal, Qc, Canada; Department of Molecular and Integrative Physiology, Université de Montréal, Montreal, Qc, Canada; Department of Pharmacology, Université de Montréal, Montreal, Qc, Canada; Department of Medicine, Université de Montréal, Montreal, Qc, Canada.
authors: Jonathan
authors: J
authors: Ledoux
mesh_terms: D000818:Animals; D001158:Arteries / Q000201:enzymology; D042783:Endothelial Cells / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008810:Mice, Inbred C57BL; D054801:Phosphoinositide Phospholipase C / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D007527:Isoenzymes; D012333:RNA, Messenger; D054801:Phosphoinositide Phospholipase C