Università Politecnica delle Marche, Department of Biochemistry, Biology and Genetics, Ancona, Italy.
Cell Prolif. 2011 Aug;44(4):330-42. doi: 10.1111/j.1365-2184.2011.00759.x. Epub 2011 Jun 6.
Umbilical cord matrix (UCM) has been recently proposed as an alternative source of mesenchymal stem cells (MSCs). The aim of this study was to isolate and characterize presumptive stem cells from intervascular and perivascular equine UCM and to obtain homogeneous subpopulations from both sites.
Umbilical cords were processed for retrieval of MSCs. Unsieved cells from intervascular and perivascular portions were evaluated for cell cycle analysis and for immunophenotyping by flow cytometry. Cells from each site were separated into larger and smaller sieved populations using multi-dishes with 8-μm pore transwell inserts. Each cell population was characterized in terms of renewal capability, specific marker expression and differentiation potential. Cryopreservation was performed on sieved cells only.
Cells from both areas expressed MSC and pluripotential specific markers and were able to differentiate into mesodermic and ectodermic lineages. The sieving procedure yielded two relatively homogeneous subpopulations with comparable characteristics. Surprisingly, after sieving, large intervascular and small perivascular cells were the most rapidly replicating cells [20.53 and 19.49 cell population doublings (PD) after 31 days respectively] and also showed higher fibroblast colony forming unit frequency. Unsieved cell populations were used as controls, and showed PD of 9.42(intervascular cells) and 8.54 (perivascular cells) after 31 days.
Here, cells from UCM represented an intermediate stage between pluripotent embryonic and adult stem cells. Size-sieving can be used to isolate more rapidly proliferating cell populations.
脐带基质（UCM）最近被提议作为间充质干细胞（MSC）的替代来源。本研究的目的是从血管间和血管周围的马 UCM 中分离和鉴定假定的干细胞，并从这两个部位获得同质的亚群。
处理脐带以获取 MSC。未筛选的血管间和血管周围部分的细胞用于细胞周期分析和流式细胞术免疫表型分析。使用带有 8μm 孔 Transwell 插入物的多盘，将每个部位的细胞分为较大和较小的筛分组。根据更新能力、特定标志物表达和分化潜能对每个细胞群进行特征描述。仅对筛选后的细胞进行冷冻保存。
两个区域的细胞均表达 MSC 和多能性特异性标志物，并能分化为中胚层和外胚层谱系。筛选过程产生了两个相对同质的亚群，具有相似的特征。令人惊讶的是，筛选后，大血管间和小血管周围细胞是增殖最快的细胞[分别在 31 天后达到 20.53 和 19.49 个细胞群体倍增（PD）]，并且成纤维细胞集落形成单位频率也更高。未筛选的细胞群体用作对照，在 31 天后分别达到 9.42（血管间细胞）和 8.54（血管周围细胞）的 PD。
这里，UCM 中的细胞代表了多能胚胎和成体干细胞之间的中间阶段。大小筛选可用于分离增殖更快的细胞群体。
