Distinguishing adipose stromal vs. stem cells by serial transplantation

再生医学和组织工程需要一个可获得的，丰富的， 满足有效性和安全性要求的可再生细胞来源。在过去的十年里， 基础科学和临床研究者已经转向脂肪组织作为细胞来源;然而， 关于脂肪衍生的蛋白质的功能特性， 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。一个真正 干细胞具有自我更新和沿着多种谱系途径分化的能力。 虽然脂肪来源的细胞已被证明在体外显示这些特征，但关键的是， <$金标准<$实验，功能性脂肪的连续移植和重建 体内贮库，在文献中从未报道过。这一修订后的R21提案测试了我们的 假设脂肪组织中含有成脂干细胞， 通过脂肪组织的胶原酶消化衍生的基质血管部分（SVF）细胞，以及 相对均质的、贴壁的、培养扩增的脂肪来源的基质/干细胞（ASC）。 目的1将使用C57 BL/6-Tg（UBC-GFP）30 cha/J小鼠模型作为容易的来源。 可追踪的GFP+脂肪来源的SVF细胞或ASC。将接种流式细胞术分选的细胞 并植入野生型C57 BL/6受体。4周后， 收获构建体并连续重复移植过程。结果 将通过流式细胞术、组织化学、共聚焦显微镜、流式细胞仪和流式细胞仪来监测和定量参数。 显微镜、扫描电子显微镜和集落形成单位测定。串行 移植完整的脂肪组织外植体作为阳性对照。目标2将 使用流式细胞术分选的人SVF细胞和ASC进行可比研究 移植到免疫缺陷小鼠体内。我们预计脂肪组织会含有 在连续移植后能够重建完整脂肪垫的干细胞群。

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.