Interstitial cells from rat middle cerebral artery belong to smooth muscle cell type

Abstract

It is now established that non-contractile cells with thin filopodia, also called vascular interstitial cells (VICs), are constitutively present in the media of many, if not all, blood vessels. The aim of this study was to determine the type of cell lineage to which arterial VICs belong using immunocytochemical, and real-time and reverse transcription PCR (RT-PCR). Using RT-PCR, we compared gene expression profiles of single VICs and smooth muscle cells (SMCs) freshly dispersed from rat middle cerebral artery. Both VICs and SMCs expressed the SMC marker, smooth muscle myosin heavy chain (SM-MHC), but did not express fibroblast, pericyte, neuronal, mast cell, endothelial or stem cell markers. Freshly isolated VICs also did not express c-kit, which is the marker for interstitial cells of Cajal in the gastrointestinal tract. Immunocytochemical labelling of contractile proteins showed that VICs and SMCs expressed SM-MHC similarly to the same degree, but VICs in contrast to SMCs had decreased expression of α-SM-actin and very low or no expression of calponin. Real-time RT-PCR was consistent with immunocytochemical experiments and showed that VICs had four times lower gene expression of calponin comparing to SMCs, which may explain VICs’ inability to contract. VICs had greater expression than SMCs of structural proteins such as non-muscular β-actin and desmin. The results obtained suggest that VICs represent a subtype of SMCs and may originate from the same precursor as SMCs, but later develop filopodia and a non-contractile cell phenotype.

New Description of Telocyte Sheaths in the Bovine Uterine Tube: An Immunohistochemical and Scanning Microscopic Study

“…Similar observations were recorded in the middle cerebral artery of the rat. Vascular interstitial cells expressed lower levels of α-SMA and higher levels of desmin than vascular smooth muscle fibers [Harhun et al, 2009]. In the human bladder, not all telocytes were α-SMA+ [Vannucchi et al, 2014].…”

Expression and function of the K+ channel KCNQ genes in human arteries

“…Endpoint PCR and quantitative PCR were performed using primers specific for human KCNQ genes (Table S1). Primers for neuronal and smooth muscle markers were adapted from Harhun et al (2009). Quantitative analysis of mRNA expression was determined using Brilliant SYBR ® Green QPCR Master Mix (Stratagene, La Jolla, CA, USA) with the Mx3005P system (Stratagene).…”

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].…”

“…The resistance-sized [19] arteries with outer diameter less than 500 μm were used in the study. The arterial preparations were used in tension recording experiments and Western blot analysis (stored at −80°C), or they were dispersed into single cells using enzymatic digestion [12] and then used for fluorescent [Ca 2+ ] i imaging and immunofluorescence experiments. For reverse transcription polymerase chain reaction (RT-PCR) analysis, a glass pipette attached to a micromanipulator was used to collect individual freshly isolated VSMCs displaying the contractile phenotype (~200 cells for each analysis).…”