|Publication Type||Journal Article|
|Year of Publication||2002|
|Authors||Chen, C-Z, Li, M, de Graaf, D, Monti, S, G,|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|Pages||15468 - 73|
|Keywords||Animals, Antigens, Biological Markers, Bone Marrow Cells, Cancer, CD, Cell Lineage, Colony-Forming Units Assay, Complementary, Congenic, DNA, Female, Flow Cytometry, Gene Expression Profiling, Gene Expression Regulation, Hematopoietic Stem Cell Transplan|
We describe a strategy to obtain highly enriched long-term repopulating (LTR) hematopoietic stem cells (HSCs) from bone marrow side-population (SP) cells by using a transgenic reporter gene driven by a stem cell enhancer. To analyze the gene-expression profile of the rare HSC population, we developed an amplification protocol termed "constant-ratio PCR," in which sample and control cDNAs are amplified in the same PCR. This protocol allowed us to identify genes differentially expressed in the enriched LTR-HSC population by oligonucleotide microarray analysis using as little as 1 ng of total RNA. Endoglin, an ancillary transforming growth factor beta receptor, was differentially expressed by the enriched HSCs. Importantly, endoglin-positive cells, which account for 20% of total SP cells, contain all the LTR-HSC activity within bone marrow SP. Our results demonstrate that endoglin, which plays important roles in angiogenesis and hematopoiesis, is a functional marker that defines LTR HSCs. Our overall strategy may be applicable for the identification of markers for other tissue-specific stem cells.