© 1998 by European Society of Cardiology
Copyright © 1998, European Society of Cardiology
Identification of phospholipase C β isoforms and their location in cultured vascular smooth muscle cells of pig, human and rat
Department of Cardiology, University of Wales College of Medicine, Heath Park, Cardiff, CF4 4XN, UK
* Corresponding author. Tel.: +44-1222-744256; fax: +44-1222-743500.
Objectives: Four phospholipase C (PLC) β isoforms have been described in pig aortic vascular smooth muscle. The aim was to determine if all four PLC β isoforms are commonly expressed in vascular smooth muscle cells (VSMC) of three species, i.e. pig, human and rat, and if the individual isoforms had distinctive intracellular distributions. Methods: Vascular smooth muscle cell cultures were derived from explants of porcine and rat aorta and a human renal artery cell line. PLC β isoform content was resolved using Western blotting. Intracellular location was determined by immunocytochemistry and confocal microscopy. Results: All three species expressed PLCs β1, β2, β3 and β4. In all species, PLC β1 demonstrated foci of concentration throughout the cytoplasm; PLC β2 demonstrated a punctate pattern that was principally at the cell periphery or was in the Golgi, depending upon the antibody used; PLC β3 was also cytoplasmic but showed a different pattern from PLC β1 and PLC β4 was cytoplasmic, except in pig quiescent cells, where it was associated with filamentous structures at the intersection with the plasma membrane. Conclusions: VSMCs of three different species express all four PLC β isoforms. Each isoform has a unique and consistent signature of distribution that is generally common to all species.
KEYWORDS Rat; Pig; Human; Vascular smooth muscle cell cultures; Phospholipase C; Intracellular localisation; Confocal microscopy