Bone marrow microenvironment is the environment in which hematopoietic stem cells live, mainly composed of bone marrow stromal cells, microvessels, nerves, and cytokines secreted by stromal cells. The bone marrow microenvironment plays a crucial role in the self-renewal, directed differentiation and proliferation of hematopoietic stem cells and the regulation of proliferation, differentiation and maturation of hematopoietic cells. A class of macrophages exists in the bone marrow microenvironment, the bone marrow-resident tissue macrophages, which plays a crucial role in maintaining homeostasis in vivo, and three subpopulations of bone marrow-resident tissue macrophages have been characterized: erythroblastic island macrophages (EIMs), hematopoietic stem cell niche macrophages, and bone macrophages. This review focuses on the functions, surface markers and modeling of EIMs.
Macrophages/cytology* ; Humans ; Erythroblasts/cytology* ; Animals ; Hematopoietic Stem Cells/cytology*

OBJECTIVETo discover the techniques for ex vivo generation and cryopreservation of erythroid progenitor cells (EPCs)derived from umbilical cord blood (UCB)mononuclear cells (MNCs).

METHODSUCB was chosen as the source of EPCs. Erythrocytes were precipitated by hydroxyethyl starch (HES). MNCs were separated by Ficoll density gradient centrifugation. Erythroid progenitor cell were generated from MNC ex vivo in suspension culture supplemented with stem cell growth factor, insulin growth factor, erythropoietin, Fms- liketyrosinekinase ligand, transferrin and dexamethasone. Cell maturation was evaluated by morphologic analysis and CD71/CD235a expression profiling. In vitro induced cells were cryopreserved using different cryopreservation media. The cell survival rate, phenotype and proliferation curves were detected after cell thawing.

RESULTSWith the extension of culture time, the total number of cells increased significantly accompanied with the elevation of CD71 and CD235 positive populations. After 14- day inducing, the cells reached to approximately 110 times of the starting number with the cell viability as (88.92±0.95)%. The percentages of cell surface markers were (86.77±9.11)% for CD71 and (64.47±16.67)% for CD71/CD235, respectively. With the extension of inducing time, wright- Giemsa staining showed that the middle erythroblasts appeared mostly at day 10, and the late erythroblasts were seen at day 14. The red pellets were present at day 14, which indicated the more production of hemoglobin. Colony forming assay showed that erythroid colonies at induction day 7 were higher than that for non-induced cells (326.00±97.96vs 61.60±20.03 per 2 000 cells). With the extension of culture time, the number of erythroid colonies decreased. Induced EPCs were preserved with different cryopreservation solutions, in which 10% DMSO were better than 5% DMSO. Additionally, 10% DMSO + 2% HSA showed no different with 10% DMSO + 5% HSA. Combined 50% plasma with 2% HSA was more effective.

CONCLUSIONSThis non- serum culture media could effectively induced and expanded EPCs, and 10% DMSO + 2% HSA + 50% plasma appeared to be a desirable cryopreservation solution for EPCs from UCB.

Cell Culture Techniques ; Cell Differentiation ; Cell Survival ; Cells, Cultured ; Cryopreservation ; methods ; Erythroblasts ; cytology ; Erythroid Precursor Cells ; cytology ; Fetal Blood ; cytology ; Humans ; Leukocytes, Mononuclear ; cytology ; Umbilical Cord

Adult ; Altitude Sickness ; metabolism ; pathology ; Apoptosis ; BH3 Interacting Domain Death Agonist Protein ; metabolism ; Erythroblasts ; cytology ; pathology ; Humans ; Male ; Middle Aged ; RNA, Messenger ; genetics ; bcl-2-Associated X Protein ; metabolism ; bcl-X Protein ; metabolism

OBJECTIVETo develop a method for identifying fetal nucleated erythrocytes (NRBCs) in maternal blood.

METHODSNRBCs in maternal blood were detected by benzidine staining and collected by micromanipulation. After primer extension preamplification (PEP) of the entire genome from a single NRBC, short tandem repeat (STR) genotype was analysed after further amplification of this gene. Single NRBC was differentiated as fetal or maternal origin by comparison of STR genotype of NRBC with its corresponding parents.

RESULTSNRBCs were found in all of 28 pregnant women in a range of 4 to 13 per 5 ml venous blood. About 43. 6% of NRBCs were determined to be fetal origin by STR typing.

CONCLUSIONThis method provides effective identification of fetal NRBCs and allows non-invasive prenatal genetic diagnosis using single fetal NRBC.

Adult ; Erythroblasts ; Erythrocyte Count ; Female ; Fetus ; cytology ; Humans ; Male ; Microsatellite Repeats ; Oligonucleotide Array Sequence Analysis ; Pregnancy ; Prenatal Diagnosis ; methods ; beta-Thalassemia ; diagnosis

A new method for noninvasive prenatal diagnosis of fetal sex was developed by using single-cell PEP-PCR techniques. Micromamipulation techniques were used to obtain single fetal cells from 273 maternal blood samples. The genome of single cells was preamplified by PEP and SRY genes were analyzed by PCR method. The SRY genes of 149 samples were detected by the new method among 153 samples carrying male fetus, while 119 out of 120 samples carrying female fetus were proved negative for SRY genes. The sensitivity and specificity of the new method were 97.39% and 99.17% respectively and the correct rate was 98.17%. The new method has the advantage of high sensitivity and specificity in noninvasive prenatal diagnosis of fetal sex and provides the basis of other researches such as sex-linked inherited diseases.
Adult ; Chromosomes, Human, Y ; Erythroblasts ; chemistry ; Female ; Fetus ; cytology ; Genes, sry ; genetics ; Genetic Diseases, Inborn ; diagnosis ; Humans ; Male ; Maternal-Fetal Exchange ; genetics ; Polymerase Chain Reaction ; methods ; Pregnancy ; blood ; Prenatal Diagnosis ; methods ; Sex Determination Processes

A new method for noninvasive prenatal diagnosis of fetal sex was developed by using single-cell PEP-PCR techniques. Micromamipulation techniques were used to obtain single fetal cells from 273 maternal blood samples. The genome of single cells was preamplified by PEP and SRY genes were analyzed by PCR method. The SRY genes of 149 samples were detected by the new method among 153 samples carrying male fetus, while 119 out of 120 samples carrying female fetus were proved negative for SRY genes. The sensitivity and specificity of the new method were 97.39% and 99.17% respectively and the correct rate was 98.17%. The new method has the advantage of high sensitivity and specificity in noninvasive prenatal diagnosis of fetal sex and provides the basis of other researches such as sex-linked inherited diseases.
Chromosomes, Human, Y ; Erythroblasts/chemistry ; Fetus/*cytology ; Genes, sry/genetics ; Genetic Diseases, Inborn/diagnosis ; Maternal-Fetal Exchange/genetics ; Polymerase Chain Reaction/methods ; Pregnancy/*blood ; Prenatal Diagnosis/*methods ; *Sex Determination (Genetics)

Embryonic hematopoiesis in mammals is characterized by successive temporal and spatial changes. Previous investigations indicate that in vitro differentiation of embryonic stem cells (ES cells) derived from 129 mice can mimic embryonic hematopoiesis to some extent. To investigate the in vitro hematopoietic differentiation capacity of ES cells derived from C57BL/6 mice, the authors initially established the murine ES cell line with standard identification methods employed. Next, two-step culture system was utilized for embryoid bodies formation and the appearance of different hematopoietic precursors was confirmed by CFC assay, cellular chemical staining as well as RT-PCR. The results demonstrated that the ES cell line MES-1 fulfilled the criteria of ES cell line and its progeny after in vitro differentiation included primitive and definitive erythrocyte precursors, mixed colony-forming cells and granulocyte/macrophage colony-forming cells. RT-PCR analysis revealed the molecular consistence of transcription factors and hematopoietic markers with cellular event. In conclusion, MES-1 established from C57BL/6 mice was able to differentiate in vitro to a variety of hematopoietic precursors, thus could partly recapitulate embryonic hematopoiesis.
Animals ; Cell Culture Techniques ; methods ; Cell Differentiation ; genetics ; Cell Line ; Colony-Forming Units Assay ; DNA-Binding Proteins ; genetics ; Embryo, Mammalian ; cytology ; Erythroblasts ; cytology ; metabolism ; Erythroid Precursor Cells ; cytology ; metabolism ; Erythroid-Specific DNA-Binding Factors ; Gene Expression ; Hematopoietic Stem Cells ; cytology ; metabolism ; Mice ; Mice, Inbred C57BL ; Mice, Inbred Strains ; Reverse Transcriptase Polymerase Chain Reaction ; Stem Cells ; cytology ; metabolism ; Time Factors ; Transcription Factors ; genetics ; Vascular Endothelial Growth Factor Receptor-2 ; genetics