OBJECTIVE: To investigate the effect and relative mechanism of Recombinant Human Thrombopoietin (rhTPO) on long-term hematopoietic recovery in mice with acute radiation sickness. METHODS: Mice were intramuscularly injected with rhTPO (100 μg/kg) 2 hours after total body irradiation with ⁶⁰Co γ-rays (6.5 Gy). Moreover, six months after irradiation, peripheral blood, hematopoietic stem cells (HSC) ratio, competitive transplantation survival rate and chimerization rate, senescence rate of c-kit⁺ HSC, and p16 and p38 mRNA expression of c-kit⁺ HSC were detected. RESULTS: Six months after 6.5 Gy γ-ray irradiation, there were no differences in peripheral blood white blood cells, red blood cells, platelets, neutrophils and bone marrow nucleated cells in normal group, irradiated group and rhTPO group (P>0.05). The proportion of hematopoietic stem cells and multipotent progenitor cells in mice of irradiated group was significantly decreased after irradiation (P<0.05), but there was no significant changes in rhTPO group (P>0.05). The counts of CFU-MK and BFU-E in irradiated group were significantly lower than that in normal group, and rhTPO group was higher than that of the irradiated group(P<0.05). The 70 day survival rate of recipient mice in normal group and rhTPO group was 100%, and all mice died in irradiation group. The senescence positive rates of c-kit⁺ HSC in normal group, irradiation group and rhTPO group were 6.11%, 9.54% and 6.01%, respectively (P<0.01). Compared with the normal group, the p16 and p38 mRNA expression of c-kit⁺ HSC in the irradiated mice were significantly increased (P<0.01), and it was markedly decreased after rhTPO administration (P<0.01). CONCLUSION The hematopoietic function of mice is still decreased 6 months after 6.5 Gy γ-ray irradiation, suggesting that there may be long-term damage. High-dose administration of rhTPO in the treatment of acute radiation sickness can reduce the senescence of HSC through p38-p16 pathway and improve the long-term damage of hematopoietic function in mice with acute radiation sickness.
Humans ; Mice ; Animals ; Thrombopoietin/metabolism* ; Hematopoietic Stem Cells ; Blood Platelets ; Recombinant Proteins/therapeutic use* ; Radiation Injuries ; RNA, Messenger/metabolism*

Thrombopoietin (TPO) can activate hematopoietic cell proliferation by its receptor c-MPL mediated downstream pathways and induce the generation of megakaryocyte. In recent years, domestic and foreign researches have confirmed that TPO/ c-MPL pathway also plays an important role in the self-renewal and quiescence of leukemia stem cell, and its expression in acute myeloid leukemia (AML) also indicates the chemotherapy resistance and poor prognosis. In this article, the research progress of the roles of TPO/c-MPL pathway in chemotherapy resistance, prognosis of AML patients, and the application of TPO/ c-MPL receptor agonists in AML were summarized briefly.
Humans ; Leukemia, Myeloid, Acute ; Neoplasm Proteins ; Proto-Oncogene Proteins/metabolism* ; Receptors, Cytokine ; Receptors, Thrombopoietin ; Signal Transduction ; Thrombopoietin

No abstract available.
Adolescent ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Amino Acid Sequence ; Calreticulin/*genetics ; Child ; DNA/chemistry/genetics/metabolism ; Exons ; Female ; Humans ; Janus Kinase 2/*genetics ; Male ; Middle Aged ; Molecular Sequence Data ; Polymorphism, Single Nucleotide ; Receptors, Thrombopoietin/genetics ; Sequence Analysis, DNA ; Sex Factors ; Thrombocythemia, Essential/*diagnosis/genetics ; Young Adult

This study was aimed to assess the effect of Astragalus Polysaccharide (ASPS) on in-vitro hematopoiesis. CFU-GM assays were used to determine the effect of ASPS and thrombopoietin (TPO) on granulocytic-monocyte progenitor cells. The CFU assays were also used to investigate the effect of ASPS on the proliferation of HL-60 cells.HL-60 cells were cultured with serum-free RPMI 1640 medium and treated with or without of different concentrations of ASPS. After 72 h incubation, the number of cells were counted.In addition, the caspase-3 and JC-1 expression was determined by flow cytometry with Annexin V/PI double staining. The results showed that ASPS (100, 200 µg/ml) and TPO (100 ng/ml) significantly promoted CFU-GM formation in vitro. Various concentrations of ASPS and TPO also promoted the colony formation of HL-60 cells, the largest effect of ASPS was observed at a concentration of 100 µg/ml. There were no synergistic effects between TPO and ASPS on cellular proliferation. The results also showed that ASPS significantly protected HL-60 cells from apoptosis in condition of serum-free medium culture, suppressed caspase 3 activation, and reduced the cell apoptosis. It is concluded that ASPS can significantly promote the formation of bone marrow CFU-GM and the proliferation of HL-60 cells, the optimal concentration of ASPS is at 100 µg/ml. In the absence of serum inducing apoptosis, ASPS also significantly reduced the apoptosis of HL-60 cells via suppressing the activation of caspase-3.
Apoptosis ; drug effects ; Astragalus Plant ; Caspase 3 ; metabolism ; Cell Proliferation ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; HL-60 Cells ; Hematopoiesis ; drug effects ; Humans ; Polysaccharides ; pharmacology ; Thrombopoietin ; pharmacology

Thrombopoietin (TPO) is a major cytokine for megakaryocytopoiesis and thrombopoiesis, and also plays an important role in the regulation of early hematopoiesis. TPO activates a number of signal pathways to exert its biological function by binding to its receptor (c-mpl). Once these signal pathways (including Jak/STAT, PI3K/Akt, Ras/MAPK) are activated, the expression of the downstream signal molecules can be changed, which then induces biological effects. Recent researches have suggested the novel functions of TPO in many systems. The receptor of TPO (c-mpl) has been shown not only present in hematological cells, but also in many other cells and organs, such as neurons, heart muscle cells, vessel endothelial cells and so on. TPO exerts a protective effect on these cells through the interaction with c-mpl. This review discusses the molecular mechanism of TPO signal and the effect of TPO on multi-nonhematopoietic cells.
Animals ; Humans ; Myocytes, Cardiac ; Neurons ; Signal Transduction ; genetics ; Thrombopoietin ; genetics ; metabolism

This study was aimed to investigate the expression of c-MPL in acute myeloid leukemia (AML) and the correlation of the c-MPL expression with CD34 and CD38, so as to define the expression of c-MPL in leukemic stem cells. The expression levels of CD34, CD38 and c-MPL were detected by flow cytometry in bone marrow cells from 29 newly diagnosed AML patients. The relationship of c-MPL positive cell ratio with clinical parameters and correlation of c-MPL with CD34 and CD38 expression in AML patients were analyzed. The results showed that expression level of c-MPL in AML patients was significantly higher than that of normal controls (P < 0.05), and the expression level of c-MPL did not correlate with age, sex, white blood cell count, AML1-ETO fusion gene and remission after chemotherapy, but the expression of c-MPL in M2 and M5 patients was higher than that of normal control (P < 0.05). Expression of c-MPL in CD34 positive AML patients was obviously higher than that in CD34 negative AML patients (P < 0.01). c-MPL was significantly higher expressed in CD34(+) cells than that in CD34(-) cells (P < 0.001), while c-MPL expression was not significantly different between CD34(+)CD38(-) and CD34(+)CD38(-) cell groups. Positive correlation between c-MPL and CD34 expression was observed (r = 0.380, P = 0.042). It is concluded that expression of c-MPL is higher in AML patients, and positively correlates with the expression level of CD34. The c-MPL expresses in leukemic stem cells.
Adolescent ; Adult ; Aged ; Case-Control Studies ; Child ; Female ; Humans ; Leukemia, Myeloid, Acute ; metabolism ; pathology ; Male ; Middle Aged ; Neoplastic Stem Cells ; metabolism ; Receptors, Thrombopoietin ; metabolism ; Young Adult

OBJECTIVETo study the expressions of erythropoietin receptor (EPOR) and thrombopoietin receptor (TPOR) on CD34+ CD59- and CD34+ CD59+ bone marrow (BM) cells from patients with paroxysmal nocturnal hemoglobinuria (PNH).

METHODS(1) The expressions of EPOR and TPOR on CD34+ CD59- and CD34+ CD59- BM cells from 26 PNH patients and 16 normal controls were examined by flow cytometry (FCM). (2) The mRNA expression of the EPOR and the TPOR in BM mononuclear cells (BMMNC) from 25 PNH patients and 13 normal controls were examined by RT-PCR.

RESULTS(1) The percentage of EPOR positive cells in PNH CD34+ CD59+ BMMNC [(30.67 +/- 18.30)%] was significantly higher than that in PNH CD34+ CD59- BMMNC [(8.05 +/- 3.51)%] (P < 0.01) and than that in control CD34+ CD59+ BMMNC [(8.24 +/- 6.51)%] (P < 0.01), but there was no obvious difference between the CD34+ CD59-BMMNC in PNH and CD34+ CD59+ BMMNC in control. (2) The percentage of TPOR positive cells in PNH CD34+ CD59+ BMMNC [(28.15 +/- 17.75)%] was significantly higher than that in PNH CD34+ CD59-BMMNC [(15.65 +/- 14.45)%] (P < 0.05) and than that in control CD34+ CD59+ BMMNC [(10.77 +/- .39)%] (P < 0.01), but there was no obvious difference between the CD34+ CD59- BMMNC in PNH and CD34+ CD59+ BMMNC in control. (3) There was no statistic difference in EPOR mRNA and TPOR mRNA expressions in BMMNCs between PNH patients group [(0.41 +/- 0.37) and (0.32 +/- 0.19), respectively] and control group [(0.47 +/- 0.33) and (0.40 +/- 0.29), respectively].

CONCLUSIONThe expression of EPOR and TPOR of PNH patients on BM CD34+ CD59+ cells are significantly higher than those on BM CD34+ CD59- cells. The difference may be due to abnormal transcription of both receptor coding genes.

Adult ; Bone Marrow Cells ; metabolism ; CD59 Antigens ; metabolism ; Case-Control Studies ; Cells, Cultured ; Female ; Flow Cytometry ; Hemoglobinuria, Paroxysmal ; metabolism ; Humans ; Male ; Middle Aged ; Receptors, Erythropoietin ; metabolism ; Receptors, Thrombopoietin ; metabolism ; Young Adult

OBJECTIVEIn order to investigate whether or not thrombopoietin (TPO) could promote the fibrogenesis of bone marrow stromal cells in absence of megakaryocytes (MKs).

METHODSImproved dexter culture system with various TPO concentrations was used for ex vivo culture of bone marrow stromal cells. Relative proliferation index, the expressions of fibronectin, laminin and type IV collagen, and the systhesis of type III procollagen were detected at different time points during culture process.

RESULTSTPO stimulated the proliferation of bone marrow stromal cells. Relative proliferation index of the stromal cells increased with the TPO concentration increasing, and was not related to the exposure time. The expressions of fibronectin, laminin, and type IV collagen appeared stronger in the TPO groups than those in the control group. But the expressions of these molecules were not dependent upon the culture time. TPO could accelerate the synthesis of type III procollagen in bone marrow stromal cells, and this acceleration was unrelated to the TPO concentration.

CONCLUSIONThese findings suggested that TPO could stimulate the stromal cells with a consequence of increased syntheses and secretions of the extracellular matrix and collagen in absence of MKs. In other words, TPO could promote the fibrogenesis of bone marrow stromal cells without the existence of MKs.

Cells, Cultured ; Collagen Type III ; metabolism ; Collagen Type IV ; metabolism ; Extracellular Matrix ; metabolism ; Fibronectins ; metabolism ; Fibrosis ; pathology ; Humans ; Laminin ; metabolism ; Megakaryocytes ; cytology ; Mesenchymal Stromal Cells ; cytology ; metabolism ; pathology ; Thrombopoietin ; pharmacology

OBJECTIVETo explore the signal transduction pathway mediated by thrombopoietin (TPO) in the inflammation model of microglia induced by lipopolysaccharide (LPS).

METHODSThe inflammation model of microglia BV2 cells was prepared by LPS of 0.5 and 1.0 μg/mL stimulation. The expression of TPO and ERK mRNA in BV2 cells was detected by real time quantitative PCR. Western blot was used to evaluate the expression of TPO and ERK protein in BV2 cells. TPO and IL-6 contents in the culture supernatant fluid were measured using ELISA.

RESULTSLPS stimulation increased significantly the mRNA and protein expression of TPO and ERK in BV2 cells, especially at the concentration of 1.0 μg/mL for 12 hrs stimulation. There was a significant positive correlation between the mRNA and protein expression of TPO and ERK.

CONCLUSIONSSignal transduction pathway of ERK1/2 participates in the activation of TPO in inflammatory injury of BV2 cells.

Animals ; Enzyme-Linked Immunosorbent Assay ; Extracellular Signal-Regulated MAP Kinases ; genetics ; metabolism ; Inflammation ; etiology ; Mice ; Microglia ; pathology ; RNA, Messenger ; analysis ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; physiology ; Thrombopoietin ; analysis ; genetics ; physiology

OBJECTIVETo explore practical protocols for cloning bone marrow-derived hepatic stem cells in vitro.

METHODSThe cell fraction rich in CD117(+) cells and CD184(+) cells was separated from fresh bone marrow by density gradient centrifugation and cultured for 0, 7 and 14 days in high-glucose DMEM supplemented with or without 10% autologous serum or in serum-free high-glucose DMEM. All the media were supplemented with different concentrations of hepatocyte growth promoting factors (HGPF), thrombopoietin (TPO) and interleukin-3 (IL-3). The quantitative changes of CD117(+) cells and CD184(+) cells were measured by flow cytometry.

RESULTSThe optimal effect for cell cloning was achieved with high-glucose DMEM with 10% autologous serum group supplemented with 40 microg/ml HGPF, 50 ng/ml TPO, and 10 ng/ml IL-3. At day 7 of cell culture in this media, the quantity of CD117(+) cells and CD184(+) cells increased by 6.55 and 6.20 folds, and by 11.62 and 20.57 folds at day 14, respectively.

CONCLUSIONIt is practical for cloning bone marrow-derived hepatic stem cells in high-glucose DMEM with 10% autologous serum supplemented with 40 microg/ml HGPF, 50 ng/ml TPO, and 10 ng/ml IL-3.

Bone Marrow Cells ; cytology ; Cell Culture Techniques ; Clone Cells ; Hepatocyte Growth Factor ; pharmacology ; Hepatocytes ; cytology ; physiology ; Humans ; Liver ; cytology ; Proto-Oncogene Proteins c-kit ; metabolism ; Stem Cells ; cytology ; Thrombopoietin ; pharmacology