Characterization of transcriptional and posttranscriptional properties of native and cultured phenotypically modulated vascular smooth muscle cells

Abstract

Various in vitro models are used for studying phenotypic modulation of vascular smooth muscle cells (VSMCs) and the established culture of vascular smooth muscle cells (cVSMCs) is most often used for this purpose. On the other hand, vascular interstitial cells (VICs) are native phenotypically modulated VSMCs present in blood vessels under normal physiological conditions. The aim of this work has been to compare the difference in expression of a number of VSMC-specific markers, which are commonly used for the characterisation of phenotypic modulation of VSMCs, between freshly dispersed VSMCs, VICs and cVSMCs from rat abdominal aorta. Our experiments show that VICs are present in the rat aorta and express markers of VSMCs. Both VICs and cVSMCs display the presence of sparse individual stress fibres enriched in alpha smooth muscle actin (αSM-actin), whereas in VSMCs, this protein is more densely packed. Compared with contractile VSMCs, both VICs and cVSMCs display decreased expression of VSMC-specific markers such as smoothelin, myosin light chain kinase and SM22α; however, the expression of two major cytoskeletal and contractile proteins (smooth muscle myosin heavy chain and αSM-actin) was downregulated in cVSMCs but not in VICs compared with contractile VSMCs. These results suggest different mechanisms for the phenotypic modulation of cVSMCs and VICs. VICs might therefore represent a novel convenient model for studying molecular mechanisms that govern the phenotypic modulation of VSMCs.

Calcium Signaling in Interstitial Cells: Focus on Telocytes

“…Vascular interstitial cells were discussed to be similar to the previously described ICCs and ICLCs [35,109,110] and were characterized in a large variety of blood vessels preparations (e.g., rabbit portal vein and mesenteric and cerebral arteries; rat portal vein, aorta and pulmonary, mesenteric, kidney, coronary and cerebral arteries; mouse aorta, mesenteric and cerebral arteries; guinea pig cerebral, portal vein, mesenteric and kidney arteries; and human mesenteric and gastro-omental arteries) [35,111,112,113,114,115,116]. It should be emphasized that in primary vascular cell cultures, vascular interstitial cells display slow rhythmical changes of the intracellular Ca 2+ concentration, while contractile vascular smooth muscle cells present faster Ca 2+ sparks [109], and that both subtypes of Ca 2+ signals are generated close to the apposition between the perinuclear Ca 2+ store and endoplasmic reticulum network [110,117].…”

Vascular smooth muscle cells from small human omental arteries express P2X1 and P2X4 receptor subunits

“…The contractile properties of isolated myocytes were confirmed with application of high potassium (60 mmol/l) solution to the experimental chamber. The non-contractile cells displaying morphological properties of the phenotypically modulated vascular myocytes, such as filopodia, [10,12,13] were omitted during collection. The description of the cell collection procedure can be found in our previous work [10].…”