Cellular Microenvironment ; Endothelial Cells ; cytology ; Hematopoietic Stem Cells ; cytology

Animals ; Cell Differentiation ; Fetus ; cytology ; Hematopoietic Stem Cells ; cytology ; Hepatocytes ; cytology ; Humans ; Liver ; cytology ; Stem Cells ; cytology ; physiology

Hematopoietic stem cells (HSC), the well-characterized adult stem cells both in the markers and function, show tremendous therapeutic potential. However, the level of hematopoietic stem cells in bone marrow is very low, which makes it difficult to work with. Based on cell surface markers and dye staining, HSC can be isolated from bone marrow and peripheral blood by using magnetic-activated cell separation and fluorescence-activated cell sorting. Over 40 years of research, many surface markers have been identified to purify mouse HSC, and CD34(-)LSK cells are regarded as the mostly used enrichment of HSC in mouse bone marrow. The purpose of this review is to provide insight into the advance of these markers, and isolation and purification of HSC.
Animals ; Cell Separation ; Flow Cytometry ; Hematopoietic Stem Cells ; cytology ; Mice

Cre-lox recombination system consists of two elements: Cre recombinase enzyme and lox sites. Cre recombinase can recombine the lox site sequences by specifically detecting and cutting them. The direction and position of lox sites determine the functional effects of Cre enzyme such as deletion, inversion or chromosomal translocation. The hematopoietic system of mouse consists of multi-lineages and various developmental stage hematopoietic cells that are differentiated from hematopoietic stem cells (hematopoietic stem cells, HSC). The hematopoietic stem cells are maintained in the bone marrow microenvironment (niche). Currently, a variety of floxed conditional-knockout mice, recognized by Cre-lox recombination system, are used for the study of the hematopoietic system. This review summarizes the commonly used Cre transgenic mice and their applications in the study of hematopoietic system.
Animals ; Hematopoietic Stem Cells ; cytology ; metabolism ; Integrases ; Mice ; Mice, Transgenic

Coculture Techniques ; Hematopoietic Stem Cells ; cytology ; Humans ; Small Molecule Libraries

OBJECTIVETo explore the mechanism of Wnt and Notch pathway involved modulating time and spatial restricted hematopoiesis.

METHODSMurine hematopoietic stem and progenitor cells (HSPCs) were isolated from bone marrow (BM) by using c-kit microbeads. E10.5 aorta-gonad-mesonephros (AGM), E12.5, E14.5, E16.5 fetal liver (FL) and adult BM derived stromal cells (StroCs) were isolated and co-cultured with c-kit(+)HSPCs. The floating cells in co-culture system were sorted and counted by FACS. Gene expressions of Wnt and Notch pathway were detected by quantitative PCR and protein expressions by immunostaining.

RESULTSCo-culturing HSPCs with AGM and FL-derived StroCs resulted in an expansion of c-kit(+)population from 0.4 x 10(5)/well to (19.2 +/- 3.2) x 10(5)/well and (26.8 +/- 5.4) x 10(5)/well, respectively, being greater than that with BM-derived StroCs (P < 0.05). The percentage of c-kit(+)cells detected in AGM- and BM- derived StroCs culture system was (75.2 +/- 7.1)%, (74.1 +/- 6.2)% respectively, being higher than FL- derived StroCs culture system (63.4 +/- 5.3)% (P < 0.05). Wnt and Notch pathway genes expression varied at different phases of hematopoiesis. Wnt was highly expressed in AGM and FL derived StroCs, and, Notch did in AGM and BM derived StroCs.

CONCLUSIONWnt and Notch pathway are important modulators in regulating time and spatial restricted hematopoiesis.

Animals ; Aorta ; cytology ; Coculture Techniques ; Hematopoiesis ; Hematopoietic Stem Cells ; cytology ; Humans ; Mesonephros ; cytology ; Stromal Cells

Hematopoietic stem cells (HSCs) are tissue specific stem cells that replenish all mature blood lineages during the lifetime of an individual. Hematopoietic cell clusters in the aorta of vertebrate embryos play a pivotal role in the formation of the adult blood system. Recently, people have learned a lot about the embryonic HSCs on their development and homing. During their differentiation, HSCs are regulated by the transcription factors, such as Runx1 and Notch signaling pathway, etc. MicroRNAs also regulate the self-renewal and differentiation of hematopoietic stem/progenitor cells on the post-transcriptional levels. Since the onset of circulation, the formation of HSCs and their differentiation into blood cells, especially red blood cells, are regulated by the hemodynamic forces. It would be of great significance if we could treat hematologic diseases with induced HSCs in vitro on the basis of fully understanding of hemotopoietic stem cell development. This review is focused on the advances in the research of HSCs' development and regulation.
Blood Cells ; cytology ; Cell Differentiation ; Embryonic Stem Cells ; cytology ; Hematopoietic Stem Cells ; cytology ; Humans ; Signal Transduction ; Transcription Factors ; physiology

Adipocytes ; cytology ; Animals ; Cell Proliferation ; Cells, Cultured ; Flow Cytometry ; Hematopoietic Stem Cells ; cytology ; Rats ; Rats, Sprague-Dawley ; Stem Cells ; cytology

This study was to establish an iron overload bone marrow (BM) model by co-culturing the mononuclear cells from BM with iron, and investigate its hematopoiesis changes. The iron overload model was set up by adding different concentration of ferric citrate (FAC) into the mononuclear cells from BM and culturing for different time, and the model was confirmed by detecting labile iron pool (LIP). Then the apoptosis of hematopoietic cells, ability of hematopoietic colony forming (CFU-E, BFU-E, CFU-GM and CFU-mix) and percentage of the CD34(+) cells of the BM cells all were determined. The changes of these indexes were tested after the iron-overloaded BM was treated with deferasirox (DFO). The results showed that after BM cells were cultured with FAC at different concentrations for different time, the LIP increased in time-and concentration-dependent manners. The intracellular LIP reached maximum level when cultured at 400 µmol/L of FAC for 24 hours. The detection of BM cell hematopoietic function found that the apoptotic rate of the FAC-treated cells (24.8 ± 2.99%) increased significantly, as compared with normal control (8.9 ± 0.96%)(p < 0.01). The ability of hematopoietic colony forming in FAC-treated cells decreased markedly, as compared with normal control (p < 0.05). The percentage of CD34(+) cells of FAC-treated cells (0.39 ± 0.07%) also decreased significantly, as compared with normal control (0.91 ± 0.12%)(p < 0.01). And these changes could be alleviated by adding DFO. It is concluded that the iron-overloaded model has been set by adding iron into the mononuclear cells from BM in vitro, and the hematopoietic function of iron-overloaded BM is deficient. These changes can be alleviated by removing the excess iron from the BM cells through treating with DFO. These findings would be helpful to further study the mechanism of iron-overload on the hematopoiesis of BM and also useful to find the way to treat iron-overload patients with hematopoietic disorders.
Bone Marrow Cells ; cytology ; Cells, Cultured ; Hematopoiesis ; Hematopoietic Stem Cells ; cytology ; Humans ; Iron ; metabolism ; Iron Overload

The basic studies selected were mainly published since 1998 and related to stem cell biology and engineering and particularly the efforts for developing new sources of hematopoietic stem/progenitor cells ex vivo. Hematopoietic cells and lymphocytes can be developed by induced differentiation in a appropriate way of culture, originating in the embryo- or adult-derived stem cells or tissue-committed stem cells which still exist in the tissue of adults. The most primitive multipotential embryonic stem cell from embryo or adult tissue has the plasticity to differentiate into every kind of progenies, the committed tissue-specific stem cell, by different proper ways of induction in vitro. The committed tissue-specific stem cell, however, can only be induced to differentiate along the line of its committed origin of tissue. No studies in China strongly confirmed yet the existence of "transdifferentiation" among the tissue- or organ-specific stem cells.
Adult ; Cell Differentiation ; Cell Lineage ; China ; Embryo, Mammalian ; cytology ; Hematopoietic Stem Cells ; cytology ; Humans ; Mesoderm ; cytology ; Models, Biological ; Pluripotent Stem Cells ; cytology ; Research ; trends ; Stem Cells ; cytology