Distinguishing adipose stromal vs. stem cells by serial transplantation

再生医学和组织工程需要可获得的、丰富的和 满足有效性和安全性要求的可重复来源的细胞。在过去的十年里， 基础科学和临床研究人员已将脂肪组织作为细胞来源；然而， 关于脂肪来源的功能同一性仍然存在很大的争议 细胞。它们是基质细胞还是干细胞？这不仅仅是语义上的区别。一句真话 干细胞既有自我更新的能力，也有沿多条谱系分化的能力。 虽然脂肪来源的细胞在体外已被证明具有这些特征，但关键的 功能性脂肪的“金标准”实验、系列移植和重建 Depot体内，从未见文献报道。这份修订后的R21提案测试了我们的 假设脂肪组织中含有成脂干细胞在两者中的异质性 脂肪组织胶原酶消化来源的基质血管成分(SVF)细胞和 相对均匀、贴壁、培养扩增的脂肪来源基质/干细胞(ASC)。 目标1将使用C57BL/6-TG(UBC-GFP)30CHA/J小鼠模型作为Easy的来源 可追踪的绿色荧光蛋白脂肪来源的SVF细胞或ASCs。流式细胞仪分选的细胞将被播种 植入野生型C57BL/6受体体内。在4周后， 构建物将被收获，移植过程将连续重复。结果 参数将通过流式细胞术、组织化学、共聚焦 显微镜、扫描电子显微镜和集落形成单位分析。连载 移植完整的脂肪组织外植体将作为阳性对照。目标2将 使用流式细胞术分选的人SVF细胞和ASC进行可比性研究 移植到免疫缺陷小鼠体内。我们预计脂肪组织将被证明含有 一种干细胞群体，能够在连续移植后重建完整的脂肪垫。

Regenerative medicine and tissue engineering require an accessible, abundant, and reproducible source of cells that fulfill efficacy and safety requirements. During the past decade, basic science and clinical investigators have turned to adipose tissue as a cell source; however, there remains substantial controversy concerning the functional identity of the adipose-derived cells. Are they ¿stromal¿ or ¿stem¿ cells? This is not simply a semantic distinction. A true ¿stem¿ cell has the ability both to self renew and to differentiate along multiple lineage pathways. While adipose-derived cells have been demonstrated to display these feature in vitro, the critical ¿gold standard¿ experiment, serial transplantation and reconstitution of a functional adipose depot in vivo, has never been reported in the literature. This revised R21 proposal tests our hypothesis that adipose tissue contains adipogenic ¿stem¿ cells in both the heterogeneous stromal vascular fraction (SVF) cells derived by collagenase digest of the adipose tissue and the relatively homogeneous, adherent, culture expanded adipose-derived stromal/stem cells (ASC). Aim 1 will employ the C57BL/6-Tg (UBC-GFP) 30cha/J mouse model as a source of easily trackable GFP+ adipose derived SVF cells or ASCs. Flow cytometry sorted cells will be seeded onto silk scaffolds and implanted into wild type C57BL/6 recipients. After a 4 week period, the constructs will be harvested and the process of transplantation repeated serially. Outcome parameters will be monitored and quantified by flow cytometry, histochemistry, confocal microscopy, scanning electron microscopy, and colony forming unit assays. Serial transplantation of intact adipose tissue explants will serve as a positive control. Aim 2 will perform comparable studies using flow cytometry sorted human SVF cells and ASC transplanted into immunodeficient mice. We anticipate that adipose tissue will prove to contain a stem cell population capable of reconstituting an intact fat pad upon serial transplantation.