The CD34 protein is regarded as a marker of stem cells from multiple origins. Recently a mesenchymal progenitor CD34 positive cell identified from traumatized human skeletal muscle demonstrates differentiation capability into vascular endothelial cells, osteoblasts and adipocytes. Here they were treated with a small inhibitory RNA for CD34, which significantly reduced the cellular level of the CD34 protein. These treated cells had a reduced capacity to proliferate, and migrate. They were both unable to differentiation down multiple pathways and to undergo vascular endothelial differentiation as reflected by a lack of expression of VE cadherin, Tie 2 and CD31. Additionally the cells were unable to form tube-like structures in an endothelial tube assay. These treated cells were also unable to undergo osteogenesis, as revealed by lack of alizarin red and alkaline phosphatase staining and were unable to undergo adipogenesis as revealed by lack of oil red O staining. Finally, when CD34 was expressed in cells lacking this protein, the cells were able to undergo vascular endothelial differentiation as revealed by expression of Tie2, VE-cadherin and CD31. These data indicate that in cells derived from traumatized muscle the CD34 protein is required for enhanced proliferation, migration and differentiation down multiple pathways.

CD34 蛋白被认为是多来源干细胞的标志物。最近，从受创伤的人类骨骼肌中鉴定出的间充质祖细胞 CD34 阳性细胞表现出分化为血管内皮细胞、成骨细胞和脂肪细胞的能力。在这里，他们用 CD34 的小抑制性 RNA 处理，这显着降低了 CD34 蛋白的细胞水平。这些处理过的细胞增殖和迁移的能力降低。它们都不能沿着多种途径分化，也不能进行血管内皮分化，这反映在缺乏 VE 钙粘蛋白、Tie 2 和 CD31 的表达上。此外，细胞不能在内皮管试验中形成管状结构。这些处理过的细胞也无法进行成骨，如缺乏茜素红和碱性磷酸酶染色所揭示的那样，并且如缺乏油红 O 染色所揭示的那样不能进行脂肪生成。最后，当 CD34 在缺乏这种蛋白质的细胞中表达时，细胞能够进行血管内皮分化，正如 Tie2、VE-钙粘蛋白和 CD31 的表达所揭示的那样。这些数据表明，在来自受创伤肌肉的细胞中，CD34 蛋白是增强增殖、迁移和沿多种途径分化所必需的。