No abstract available.
Autopsy* ; Down Syndrome* ; Leukemia* ; Megakaryocyte Progenitor Cells*

No abstract available.
Autopsy* ; Down Syndrome* ; Leukemia* ; Megakaryocyte Progenitor Cells*

No abstract available.
Down Syndrome* ; Humans ; Infant, Newborn* ; Megakaryocyte Progenitor Cells*

No abstract available.
Blast Crisis* ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive* ; Megakaryocyte Progenitor Cells*

OBJECTIVE: To investigate the effect of Rheb1 in the development of mouse megakaryocyte-erythroid progenitor cells and its related mechanism. METHODS: Rheb1 was specifically knocked-out in the hematopoietic system of Vav1-Cre;Rheb1^fl/fl mice(Rheb1^Δ/Δ mice). Flow cytometry was used to detect the percentage of red blood cells in peripheral blood and erythroid cells in bone marrow in Vav1-Cre;Rheb1^fl/fl mice and control mice. The CFC assay was used to detect the differentiation ability of Rheb1 KO megakaryocyte-erythroid progenitor cells and control cells. Real-time fluorescence quantification PCR was used to detect the relative expression of PU.1,GATA-1,GATA-2,CEBPα and CEBPβ of Rheb1 KO megakaryocyte-erythroid progenitor cells and control cells. Rapamycin was added to the culture medium, and it was used to detect the changes in cloning ability of megakaryocyte-erythroid progenitor cells from wild-type mice in vitro. RESULTS: After Rheb1 was knocked out, the development and stress response ability of megakaryocyte-erythroid progenitor cells in mice were weaken and the differentiation ability of megakaryocyte-erythroid progenitor cells in vitro was weaken. Moreover, the expression of GATA-1 of megakaryocyte-erythroid progenitor cells was decreased. Further, rapamycin could inhibit the differentiative capacity of megakaryocyte-erythroid progenitor cells in vitro. CONCLUSION Rheb1 can regulate the development of megakaryocyte-erythroid progenitor cells probably through the mTOR signaling pathway in mice.
Animals ; Cell Differentiation ; Erythrocytes ; Flow Cytometry ; Megakaryocyte-Erythroid Progenitor Cells ; Megakaryocytes ; Mice ; Signal Transduction

PURPOSE: We investigated the expression of vasoactive intestinal peptide (VIP), VIP receptor 1 (VPAC1), VIP receptor 2 (VPAC2) genes in the human umbilical cord blood CD34 cells, and the ability of VIP to stimulate human primitive as well as monopotent hematopoietic progenitors. METHODS: We isolated RNA from umbilical cord blood CD34 cells, and then performed RT-PCR, and sequencing. The umbilical cord blood CD34 cells were cultured with the various concentrations of VIP for burst-forming unit of erythrocyte (BFU-E), colony-forming unit of granulocyte/monocyte (CFU-GM), colony-forming unit of graulocyte/erythrocyte/monocyte/megakaryocyte (CFU-GEMM), and colony-forming unit of megakaryocyte (CFU-Mk). RESULTS: The RNA coding for VPAC1 was detected in human umbilical cord blood CD34 cells. VIP significantly stimulated the growth of CFU-GEMM and CFU-Mk. CONCLUSION: The present results suggest that VIP is an important neuropeptide in the early proliferation of human primitive as well as megakaryocyte progenitors.
Clinical Coding ; Erythrocytes ; Fetal Blood* ; Humans ; Megakaryocyte Progenitor Cells ; Megakaryocytes ; Myeloid Progenitor Cells ; Neuropeptides ; Receptors, Vasoactive Intestinal Peptide ; RNA ; Stem Cells ; Vasoactive Intestinal Peptide*

OBJECTIVETo study the expansion potential of megakaryocyte progenitor cells (MPC) from human placenta tissue CD133+ (PT-CD133+) cells.

METHODSPT-CD133+ cells were purified from mononuclear cells (MNC) by magnetic activated cell sorting (MACS) and seeded in serum-free liquid culture medium supplemented with thrombopoietin (TPO), interleukin-3 (IL-3), and stem cell factor (SCF) to expand MPC. At day 7, 10 and 14, the total cell number was counted and the dynamic changes of CD133, CD34, and CD41 antigens expression during ex-vivo expansion were analyzed by flow cytometry (FCM). PT-CD133+ cells at different expansion time were collected and cultured in collagen semisolid medium for colony forming units-megakaryocyte (CFU-MK) assay.

RESULTSPT-CD133+ cells could be optimally expanded at day 7 by 13 +/- 2 fold increase in serum-free liquid culture systems and the total cell number was expanded by 160 fold at day 14. With the expansion time going on, the expression of CD133, CD34 decreased and that of CD41 increased. The expanded megakaryocytes were immature and no sign of platelet formation. Both PT-CD133+ cells before and after expansion could form CFU-MK, the total number of CFU-MK peaked at day 10 of expansion by 54 +/- 10 fold increase.

CONCLUSIONHuman PT-CD133+ cells have a high capacity of MPC expansion, 10 days culture could give rise to the maximum number of CFU-MK.

AC133 Antigen ; Antigens, CD ; Cell Differentiation ; Cells, Cultured ; Female ; Glycoproteins ; Humans ; Megakaryocyte Progenitor Cells ; cytology ; Peptides ; Placenta ; cytology ; Pregnancy

This study was purposed to investigate the biological characteristics and immunogenicity changes of ex vivo expanded megakaryocyte progenitors from human umbilical cord blood CD34(+) cells in order to provide experimental basis for clinical application of ex vivo expanded umbilical cord blood megakaryocyte progenitor cells. Mononuclear cells (MNCs) were obtained from umbilical cord blood by Ficoll-Hyapaque density gradient separation. CD34(+) cells were enriched by magnetic cell sorting (MACS). The selected CD34(+) cells were seeded in serum-free medium stimulated with thrombopoietin (TPO, 50 ng/ml), interleukin 11 (IL-11, 50 ng/ml), and heparin (25 U/ml) for 14 days. The immunophenotyping (CD34(+), CD41a(+), CD61(+), CD34(+) CD41a(+) and CD34(+) CD61(+) cells) of amplificated products, matured megakaryocyte apoptosis, and expression of human leukocyte antigen (HLA) class I and class II molecules were measured by fluorescence-activated cell sorter (FACS). The number of colony-forming units-megakaryocyte (CFU-Mk) was also evaluated by CFU-Mk assay. The results showed that the umbilical cord blood CD34(+) mononuclear cells could be effectively differentiated into megakaryocytes. The peak expression ratios of CD41a(+) and CD61(+) cells were all at 14th days, while that of CD34(+) CD41(+) and CD34(+) CD61(+) cells were at 7th day [(3.41 +/- 2.80)% and (1.89 +/- 1.43)%, respectively]. The expansion times of large and small CFU-Mk reached peak at 7th day (20.66 +/- 32.79) and 10th day (435.62 +/- 482.65), respectively. The apoptotic rates of megakaryocytes at 7th, 10th, 14th day were (19.48 +/- 9.64)%, (26.87 +/- 9.03)%, and (52.46 +/- 11.74)%, respectively. The apoptotic rate of megakaryocytes had no significant difference in 7 and 10 days culture (p > 0.05), while that significantly increased in culture for 14 day culture, compared with culture for 7 and 10 days (p < 0.05, respectively). The expression of HLA class I and class II molecules on megakaryocytes decreased along with the prolongation of expansion time and sharply decreased in 0 to 10 days. It is concluded that the cytokines of TPO, IL-11, and heparin can promote the expansion of megakaryocyte progenitors from umbilical cord blood CD34(+) mononuclear cells effectively in vitro. The peaked expansion times of large CFU-Mk, the peaked expression ratios of CD34(+) CD41(+) and CD34(+) CD61(+) cells were all at 7th day. So the culture for 7 days appeared to be the optimal duration of expanding megakaryocyte progenitors.
Antigens, CD34 ; immunology ; Cell Differentiation ; Cell Division ; Cell Separation ; Cells, Cultured ; Fetal Blood ; cytology ; immunology ; Humans ; Megakaryocyte Progenitor Cells ; cytology

Acute megakaryoblastic leukemia is a rare and rapidly fatal disease characterized by proliferation of megakaryocyte series and atypical megakaryocytes in the bone marrow. Acute megakaryoblastic leukemia is suspicious when 1) megakaryocyte in peripheral blood, mixture of large and small mononuclear megakaryoblast in the bone marrow 2) cytoplasmic budding in blast 3) myelofibrosis (dense medullary overgrowth of reticulin fibers) 4) PAS (+), ANAE (+), SBB (−), peroxidase (−) and which is confirmed by platelet peroxidase oxidation on electron microscope or monoclonal antibody. A case of acute megakaryoblastic leukemia was studied morphologically and monoclonal antibody.
Blood Platelets ; Bone Marrow ; Cytoplasm ; Leukemia, Megakaryoblastic, Acute* ; Megakaryocyte Progenitor Cells ; Megakaryocytes ; Naphthol AS D Esterase ; Peroxidase ; Primary Myelofibrosis ; Reticulin

We experienced a case of congenital acute megakaryoblastic leukemia with Down syndrome. The patient was admitted due to characteristic facial figure of Down syndrome and abdominal distension. Acute megakaryoblastic leukemia was diagnosed with abundant megakaryoblast in peripheral blood smear, severe myelofibrosis in bone marrow biopsy and positive platelet glycoprotein III a receptor. On third hospital day, the patient expired due to DIC and pulmonary hemorrhage. Authors report the case with review of literature.
Biopsy ; Blood Platelets ; Bone Marrow ; Dacarbazine ; Down Syndrome* ; Glycoproteins ; Hemorrhage ; Humans ; Leukemia, Megakaryoblastic, Acute* ; Megakaryocyte Progenitor Cells ; Primary Myelofibrosis