Ion Channels and Cell Signalling Centre, Division of Basic Medical Sciences, St. George's, University of London, London, United Kingdom.
J Cell Mol Med. 2009 Nov-Dec;13(11-12):4532-9. doi: 10.1111/j.1582-4934.2008.00567.x. Epub 2008 Oct 31.
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 alpha-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 beta-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.
现在已经确定，具有细丝状伪足的非收缩细胞，也称为血管间质细胞（VICs），在许多（如果不是全部）血管的中膜中持续存在。本研究的目的是使用免疫细胞化学和实时及反转录 PCR（RT-PCR）确定动脉 VIC 属于哪种细胞谱系。我们使用 RT-PCR 比较了从大鼠大脑中动脉新鲜分散的单个 VIC 和平滑肌细胞（SMCs）的基因表达谱。VIC 和 SMC 均表达 SMC 标志物平滑肌肌球蛋白重链（SM-MHC），但不表达成纤维细胞、周细胞、神经元、肥大细胞、内皮细胞或干细胞标志物。新鲜分离的 VIC 也不表达胃肠道间充质细胞 Cajal 的标志物 c-kit。收缩蛋白的免疫细胞化学标记显示，VIC 和 SMC 以相似的程度表达 SM-MHC，但与 SMC 相比，VIC 的 alpha-SM-actin 表达减少，钙调蛋白表达非常低或没有。实时 RT-PCR 与免疫细胞化学实验一致，表明 VIC 的钙调蛋白基因表达比 SMC 低四倍，这可能解释了 VIC 无法收缩的原因。VIC 的结构蛋白如非肌肉β-肌动蛋白和结蛋白的表达高于 SMC。研究结果表明，VIC 代表 SMC 的一种亚型，可能与 SMC 来自相同的前体，但后来发育出丝状伪足和非收缩细胞表型。
