Bioresource Collection and Research Center, Food Industry Research and Development Institute, Hsinchu, Taiwan.
Bioresource Collection and Research Center, Food Industry Research and Development Institute, Hsinchu, Taiwan.
Cytotherapy. 2014 Apr;16(4):560-5. doi: 10.1016/j.jcyt.2013.10.009. Epub 2013 Dec 22.
Very small embryonic-like (VSEL) stem cells are a rare cell population present in bone marrow, cord blood and other tissues that displays a distinct small cell size and the ability to give rise to cells of the three germ layers. VSEL stem cells were reported to be discarded in the red blood cell fraction by Ficoll-Paque density gradient centrifugation during the processing of bone marrow and cord blood specimens. However, most cord blood banks do not include density gradient centrifugation in their procedures while red blood cells are removed by Hespan sedimentation following the Cord Blood Transplantation Study cord blood bank standard operating procedures (COBLT SOP). To clarify the retention of VSEL stem cells, we investigated the recovery of VSEL stem cells following COBLT SOP guidelines.
The recovery of CD45(-)/Lin(-)/SSEA-4(+) VSEL stem cells of umbilical cord blood was examined by flow cytometry before and after COBLT SOP processing, and relative expression of pluripotent genes was analyzed by quantitative polymerase chain reaction.
CD45(-)/Lin(-)/SSEA-4(+) VSEL stem cells were mostly recovered in the final products following COBLT SOP guidelines. The expression of pluripotent genes could be maintained at >80% in products after hetastarch (Hespan; B. Braun Medical Inc., Irvine, CA, USA) processing.
The rare sub-population of CD45(-)/Lin(-)/SSEA-4(+) VSEL stem cells survived after Hespan sedimentation. This finding suggests that umbilical cord blood units cryopreserved by COBLT SOP in cord blood banks should retain most VSEL stem cells present in the un-processed specimens.
非常小的胚胎样（VSEL）干细胞是一种存在于骨髓、脐带血和其他组织中的稀有细胞群体，具有明显的小细胞大小和分化为三个胚层细胞的能力。据报道，在骨髓和脐带血标本的处理过程中，通过菲可密度梯度离心，VSEL 干细胞会被丢弃在红细胞部分。然而，大多数脐带血库在其程序中不包括密度梯度离心，而是在遵循脐带血移植研究脐带血库标准操作程序（COBLT SOP）时通过 Hespan 沉降去除红细胞。为了阐明 VSEL 干细胞的保留情况，我们研究了 COBLT SOP 指南下脐带血中 VSEL 干细胞的回收情况。
通过流式细胞术在 COBLT SOP 处理前后检查脐带血中 CD45(-)/Lin(-)/SSEA-4(+) VSEL 干细胞的回收情况，并通过定量聚合酶链反应分析多能基因的相对表达。
COBLT SOP 指南下，大多数 CD45(-)/Lin(-)/SSEA-4(+) VSEL 干细胞在最终产物中得到回收。在 Hestarch（Hespan；B. Braun Medical Inc.，Irvine，CA，USA）处理后，多能基因的表达可以保持在产品中的>80%。
在 Hestarch 沉降后，CD45(-)/Lin(-)/SSEA-4(+) VSEL 干细胞的稀有亚群得以存活。这一发现表明，COBLT SOP 保存在脐带血库中的脐带血单位应保留未处理标本中存在的大多数 VSEL 干细胞。
