來(lái)自印第安納大學(xué)醫(yī)學(xué)院的研究者近期研究發(fā)現(xiàn)血管細(xì)胞新功能,。血管壁細(xì)胞是維持血管形態(tài)和功能的重要成分,，新發(fā)現(xiàn)表明血管壁細(xì)胞還是控制脂肪細(xì)胞發(fā)育的重要因子。研究成果發(fā)表在近期Stem Cells上面,。
研究者發(fā)現(xiàn),，祖細(xì)胞或者說(shuō)干細(xì)胞接觸血管內(nèi)皮細(xì)胞后發(fā)育成為脂肪細(xì)胞的趨勢(shì)顯著降低。
據(jù)文章作者,，印第安納大學(xué)醫(yī)學(xué)院血管生物和醫(yī)學(xué)研究中心研究員Keith L.March介紹,，研究者在觀(guān)察脂肪組織的基質(zhì)細(xì)胞時(shí)發(fā)現(xiàn)一旦接觸毛細(xì)血管或是微血管內(nèi)皮細(xì)胞時(shí)，基質(zhì)細(xì)胞分化成脂肪細(xì)胞的幾率就顯著下降,。
印第安納大學(xué)醫(yī)學(xué)院生理學(xué)和生物工程學(xué)教授March博士介紹道,，首先研究者只是觀(guān)察到基質(zhì)細(xì)胞與內(nèi)皮細(xì)胞接觸后發(fā)生變化的現(xiàn)象，沒(méi)有人知道究竟是什么樣的機(jī)制讓這一切發(fā)生,。因此,，研究者希望通過(guò)實(shí)驗(yàn)了解個(gè)中的機(jī)制。
科學(xué)家從脂肪組織提取脂肪干細(xì)胞,，把脂肪干細(xì)胞與血管內(nèi)皮細(xì)胞混合在一起,，結(jié)果發(fā)現(xiàn)脂肪干細(xì)胞分化成為成熟脂肪細(xì)胞的幾率大大下降。他們發(fā)現(xiàn),，血管內(nèi)皮細(xì)胞會(huì)釋放一種蛋白,，Wnt，這一因子在脂肪細(xì)胞的發(fā)育過(guò)程中起關(guān)鍵的作用,。Wnt在多種組織里存在,，對(duì)組織細(xì)胞的發(fā)育和分化起調(diào)控作用，并且在老化過(guò)程中也起作用,。
研究者推測(cè),，修復(fù)受損的血管內(nèi)皮細(xì)胞可能對(duì)阻斷脂肪細(xì)胞的發(fā)育具有積極意義。現(xiàn)在已經(jīng)清楚血管內(nèi)皮細(xì)胞是通過(guò)Wnt來(lái)調(diào)節(jié)脂肪細(xì)胞的發(fā)育，但是對(duì)于脂肪細(xì)胞對(duì)血管內(nèi)皮細(xì)胞的反作用暫時(shí)不清楚,。研究者希望通過(guò)深入的研究可以揭開(kāi)這一謎團(tuán),。
研究者推測(cè)，功能異常的血管內(nèi)皮細(xì)胞會(huì)促進(jìn)脂肪細(xì)胞發(fā)育,，并伴隨新血管生成,。研究者希望打破這一循環(huán)。新的研究成果可能對(duì)心血管疾病和肥胖癥治療具有指導(dǎo)意義,。（生物谷Bioon.com）
生物谷推薦原始出處：
Stem Cells First published online July 31, 2008
IFATS Series: Adipose Stromal Cell Differentiation is Reduced by Endothelial Cell Contact and Paracrine Communication: Role of Canonical Wnt-Signaling
Gangaraju Rajashekhar, Dmitry O. Traktuev, Christopher William Roell, Brian H. Johnstone, Stephanie Merfeld-Clauss, Bruce Van Natta, Elliot D. Rosen, Keith L March, Matthias Clauss
Adipose stromal cells (ASC) are multipotential mesenchymal progenitor cells which are readily induced to undergo adipogenic differentiation, and we have recently demonstrated to have functional and phenotypic overlap with pericytes lining microvessels in adipose tissues. In this study we addressed the hypothesis that modulation of ASC fate within this perivascular niche can occur via interaction with endothelial cells (EC) which serve to modulate the adipogenic potential of ASC. To this end, we investigated contact as well as paracrine effects of EC on ASC adipogenesis in 2D-co-culture and via conditioned media, and analyzed mutual gene expression changes by real time RT-PCR. A significant decrease in adipogenic differentiation was observed in ASC when co-cultured with EC but not control fibroblasts. This endothelial cell-specific effect was accompanied by increased expression of factors involved in Wnt signaling; most prominently Wnt1, Wnt4 and Wnt10a, well known inhibitors of adipogenesis. Suppression of Wnt1, but not Wnt 10a or scrambled control siRNA in co-cultures partially reversed the endothelial cell effect, thus increasing adipogenic differentiation, suggesting a plausible role of Wnt1 ligand in modulation of adipogenesis by the vasculature. Furthermore, addition of recombinant Wnt ligand or the Wnt signaling agonist inhibited adipogenic differentiation of ASC in the absence of EC. In conclusion, these data define the relationship in adipose tissue between ASC and EC in the perivascular niche, in which the latter act to repress adipogenesis, thereby stabilizing vasculature. It is tempting to speculate that abnormal endothelial function may be associated with pathologic de-repression of adipogenesis.
