Sidney Laura E, Branch Matthew J, Dunphy Siobhán E, Dua Harminder S, Hopkinson Andrew
Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Queen's Medical Centre Campus, Nottingham, United Kingdom.
Stem Cells. 2014 Jun;32(6):1380-9. doi: 10.1002/stem.1661.
CD34 is a transmembrane phosphoglycoprotein, first identified on hematopoietic stem and progenitor cells. Clinically, it is associated with the selection and enrichment of hematopoietic stem cells for bone marrow transplants. Due to these historical and clinical associations, CD34 expression is almost ubiquitously related to hematopoietic cells, and it is a common misconception that CD34-positive (CD34(+) ) cells in nonhematopoietic samples represent hematopoietic contamination. The prevailing school of thought states that multipotent mesenchymal stromal cells (MSC) do not express CD34. However, strong evidence demonstrates CD34 is expressed not only by MSC but by a multitude of other nonhematopoietic cell types including muscle satellite cells, corneal keratocytes, interstitial cells, epithelial progenitors, and vascular endothelial progenitors. In many cases, the CD34(+) cells represent a small proportion of the total cell population and also indicate a distinct subset of cells with enhanced progenitor activity. Herein, we explore common traits between cells that express CD34, including associated markers, morphology and differentiation potential. We endeavor to highlight key similarities between CD34(+) cells, with a focus on progenitor activity. A common function of CD34 has yet to be elucidated, but by analyzing and understanding links between CD34(+) cells, we hope to be able to offer an insight into the overlapping properties of cells that express CD34.
CD34是一种跨膜磷酸糖蛋白，最初在造血干细胞和祖细胞上被识别。在临床上，它与骨髓移植中造血干细胞的选择和富集相关。由于这些历史和临床关联，CD34的表达几乎普遍与造血细胞相关，并且存在一种常见的误解，即非造血样本中的CD34阳性（CD34(+)）细胞代表造血污染。主流观点认为多能间充质基质细胞（MSC）不表达CD34。然而，有力证据表明，不仅MSC表达CD34，许多其他非造血细胞类型也表达CD34，包括肌肉卫星细胞、角膜角膜细胞、间质细胞、上皮祖细胞和血管内皮祖细胞。在许多情况下，CD34(+)细胞仅占总细胞群的一小部分，并且还表明具有增强祖细胞活性的细胞亚群。在此，我们探讨表达CD34的细胞之间的共同特征，包括相关标志物、形态和分化潜能。我们致力于突出CD34(+)细胞之间的关键相似性，重点是祖细胞活性。CD34的共同功能尚未阐明，但通过分析和理解CD34(+)细胞之间的联系，我们希望能够深入了解表达CD34的细胞的重叠特性。
