Gene expression profile of murine long-term reconstituting vs. short-term reconstituting hematopoietic stem cells

Abstract

The hematopoietic stem cell (HSC) compartment is composed of long-term reconstituting (LTR) and short-term reconstituting (STR) stem cells. LTR HSC can reconstitute the hematopoietic system for life, whereas STR HSC can sustain hematopoiesis for only a few weeks in the mouse. Several excellent gene expression profiles have been obtained of the total hematopoietic stem cell population. We have used five-color FACS sorting to isolate separate populations of LTR and STR stem cell subsets. The LTR HSC has the phenotype defined as Lin ؊ Sca ؉ Kit ؉ 38 ؉ 34 ؊ ; two subsets of STR HSC were obtained with phenotypes of Lin ؊ Sca ؉ Kit ؉ 38 ؉ 34 ؉ and Lin ؊ Sca ؉ Kit ؉ 38 ؊ 34 ؉ . The microarray profiling study reported here was able to identify genes specific for LTR functions. In the interrogated genes (Ϸ12,000 probe sets corresponding to 8,000 genes), 210 genes are differentially expressed, and 72 genes are associated with LTR activity, including membrane proteins, signal transduction molecules, and transcription factors. Hierarchical clustering of the 210 differentially expressed genes suggested that they are not bone marrow-specific but rather appear to be stem cell-specific. Transcription factor-binding site analysis suggested that GATA3 might play an important role in the biology of LTR HSC.microarray ͉ regulation

Cited2 is required for normal hematopoiesis in the murine fetal liver

“…As shown in Figure 1A, Cited2 expression was detected in LSK and Lin Ϫ c-Kit ϩ fetal liver cells at 14.5 dpc. Real-time PCR analysis detected higher expression of Cited2 in LSK cells than in Lin Ϫ c-Kit ϩ cells from fetal liver ( Figure 1B), which is consistent with the finding that Cited2 is highly expressed in LTR stem cells 17 and suggests that Cited2 might be associated with the HSC function in mouse fetal liver.…”

“…Cited2 expression has been detected in mouse bone marrow HSCs and shown to be positively related to LTR stem cell activity. 17 We have detected Cited2 expression in fetal liver-derived hepatoblasts and hepatocytes (data not shown). Detailed analysis of Cited2 expression in Lin Ϫ c-Kit ϩ Scal-1 ϩ (LSK) and Lin Ϫ c-Kit ϩ fetal liver cells was further performed in sorted cells by reverse-transcription (RT)-PCR.…”

“…17 Cited2 is ubiquitously expressed, and its expression has been detected in the hematopoietic and nonhematopoietic lineages in the fetal liver. We have shown by the limiting dilution/CRU assay that Cited2 plays a cellautonomous role in fetal liver hematopoiesis; however, our study cannot rule out the possible extrinsic effect of Cited2 on HSC functions.…”

“…16 A recent gene expression profiling study to identify specific genes with long-term reconstitution (LTR) stem cell activity showed that expression of Cited2 correlates positively with LTR HSC activity. 17 Cited2 expression during development is detected at multiple sites that form mesodermal structures 5,18 from which HSCs are derived. 19,20 All of these findings are suggestive of a potential role of Cited2 in hematopoiesis.…”

In search of rat stem Leydig cells: Identification, isolation, and lineage-specific development

“…2E), and most (84 Ϯ 5%, mean Ϯ SEM, n ϭ six separate preparations) also expressed c-kit ( Fig. 2F), two common markers for stem cells (14,15). The majority were also positive for the GATA4 transcription factor (Fig.…”