Smooth muscle progenitor cells in human blood
Smooth muscle progenitor cells in human blood
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DOI：
10.1161/01.cir.0000031525.61826.a8
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发表时间：
2002-09-03
期刊：
影响因子：
37.8
通讯作者：
Caplice, NM
中科院分区：
文献类型：
--
作者：
Simper, D;Stalboerger, PG;Caplice, NM
背景-最近的动物数据表明，血管壁新生内膜内的血管平滑肌细胞可能来自骨髓，这为循环中的平滑肌前体细胞(SPC)提供了间接证据。目前尚不存在人类受试者循环中SPC的证据，这种假定的SPC可能存在于斑块形成部位的机制目前尚不清楚，但可能涉及特定表面黏附分子的表达，如整合素。本研究旨在从人外周血中分离培养SPC，并对其表面整合素的表达进行鉴定。方法和结果：从棕黄色大衣中分离的人单个核细胞接种于1型胶原基质上，并在内皮生长介质(EGM-2)或EGM-2和血小板衍生生长因子BB中筛选出生长细胞。在血小板衍生生长因子BB强化的培养液中的选择导致SOC在4个月内迅速生长并扩大到>；40种群倍增。免疫荧光和Western blotting显示这些细胞表达平滑肌细胞特异性α-肌动蛋白(α-SMA)、肌球蛋白重链和钙蛋白，CD34、Flt1和Flk1受体阳性，而Tie-2受体表达阴性，提示可能是骨髓血管母细胞起源。相反，单独在EGM-2中生长的内皮生长细胞(EOCs)和最初的MNC群体对这些平滑肌特异性标志物都是阴性的。流式细胞术和Western blotting显示，整合素α(5)β(1)在SOC中的表达显著高于EOCs，并且SOC与纤维连接蛋白的粘附力增加了8倍(P<；0.001)，这一效应可以用α(5)β(1)抗体来降低。最后，与相似传代的EOCs相比，SOC在体外表现出明显更大的增殖潜力(P<；0.001)。结论：本研究首次证实了人类血液中SPC具有特定的生长、黏附和整合素谱。这些数据对我们理解成人血管平滑肌细胞的分化、增殖和归巢有重要意义。
Background-Recent animal data suggest that vascular smooth muscle cells within the neointima of the vessel wall may originate from bone marrow, providing indirect evidence for circulating smooth muscle progenitor cells (SPCs). Evidence for circulating SPCs in human subjects does not exist, and the mechanism whereby such putative SPCs may home to sites of plaque formation is presently not understood but is likely to involve expression of specific surface adhesion molecules, such as integrins. In this study, we aimed to culture smooth muscle outgrowth cells (SOCs) from SPCs in human peripheral blood and characterize surface integrin expression on these cells.Methods and Results-Human mononuclear cells isolated from buffy coat were seeded on collagen type 1 matrix and outgrowth cells selected in endothelial growth medium (EGM-2) or EGM-2 and platelet-derived growth factor BB. Selection in platelet-derived growth factor BB-enriched medium caused rapid outgrowth and expansion of SOC to > 40 population doublings in a 4-month period. These SOCs were positive for smooth muscle cell-specific alpha actin (alphaSMA), myosin heavy chain, and calponin on immunofluorescence and Western blotting and were also positive for CD34, Flt1, and Flk1 receptor but negative for Tie-2 receptor expression, suggesting a potential bone marrow angioblastic origin. In contrast, endothelial outgrowth cells (EOCs) grown in EGM-2 alone and the initial MNC population were negative for these smooth muscle-specific markers. Integrin alpha(5)beta(1) expression by FACS and Western blotting was significantly increased in SOCs compared with EOCs, and this was confirmed by 8-fold greater adhesion of SOC to fibronectin (P < 0.001), an effect that could be decreased using an alpha(5)beta(1) antibody. Finally, SOC showed a significantly greater in vitro proliferative potential compared with EOCs of similar passage (P < 0.001).Conclusions-This study demonstrates for the first time outgrowth of smooth muscle cells with a specific growth, adhesion, and integrin profile from putative SPC in human blood. These data have implications for our understanding of adult vascular smooth muscle cell differentiation, proliferation, and homing.