The main physiological function of megakaryocytes is the production of platelets, whose development, maturation and platelet production are a complex regulatory process, and are involved in many factors. In recent years it was found that the lung is also the main site of megakaryocyte-producing platelets in addition to bone marrow. Based on the findings of recent years, this review summarizes the process of megakaryocyte development, maturation and platelet production, with emphasis on the analyzing the regulatory effects of apoptotic factors, miRNA, thrombopoietin and its receptors, interleukins, transcription factors and their corresponding signal pathways on platelet production. To understand the regulatory mechanism of platelet production can help to understand the pathological mechanism of platelet-related diseases and provide new ideas for the diagnosis and treatment of platelet-related diseases.
Blood Platelets ; Bone Marrow Cells ; Megakaryocytes ; Thrombopoiesis ; Thrombopoietin

BACKGROUND: The megakaryopoiesis and platelet production is regulated by several hematopoietc factors such as thrombopoietin (TPO), interleukin-11 (IL-11) and interleukin-3 (IL-3). IL-11 is a potent stimulator of megakaryopoiesis in vivo, and acts primarily as a megakaryocyte maturation factor in vitro and it can act synergistically with IL-3 and TPO. We performed this study to investigate the effects of recombinant human IL-11 (rhIL-11) with other hematopoietic factors on megakaryocyte colony formation in vitro. METHODS: CD34+ cells were separated from umbilical cord blood and megakaryocyte colonies using MegaCult Assay Kit were cultured with rhIL-11, recombinant human IL-3 (rhIL-3), and recombinant human TPO (rhTPO) for 7 and 14 days. The number and percentage of CD34+ and CD41a+ cells were determined by flowcytometry. RESULTS: The number of CD41a+ cells were 0.54+/-0.05x10(4) (rhIL-11 100 ng/ml), 5.32+.-0.23x10(4) (rhIL-3 100 ng/ml), and 8.76+/-0.15x10(4) (rhTPO 50 ng/ml) of total expanded cells during the culture of the purified CD34+ cells in liquid phase for 7 days. The number of CD41a+ cells were increased to 7.47+/-0.69x10(4) (rhIL-3 rhIL-11), 11.92+/-0.19x10(4) (rhTPO rhIL-11) of total expanded cells, respectively, during the culture of the purified CD34+ cells in liquid phase for 7 days in the presence of rhIL-11 (100 ng/ml). When the purified CD34+ cells were cultured in semisolid media including various concentration of rhIL-11, the megakaryocyte colonies were not formed. When the purified CD34+ cells were cultured with rhIL-11 and rhTPO or with rhIL-11 and rhIL-3, the number of megakaryocyte colonies were increased compared with rhTPO or rhIL-3 alone. CONCLUSION: These results indicate that IL-11 exerts a potent proliferative activity to colony forming unit-megakaryocyte from human umbilical cord blood, and it acts with other hematopoietic factors synergistically
Blood Platelets ; Fetal Blood* ; Humans ; Interleukin-11* ; Interleukin-3 ; Megakaryocytes ; Thrombopoietin ; Umbilical Cord*

To explore influence of platelet donation on donor's megakaryocytopoiesis, platelet counts and plasma concentrations of thrombopoietin (TPO), interleukin-3 (IL-3), IL-6 and nitric oxide (NO) were determined in 42 frequent platelet donors (undergoing plateletpheresis more than once a month for 24 months and their mean platelet yield of collection was 2.5 x 10(11)), in 62 limited platelet donors (undergoing plateletpheresis less than once a month for 24 months) after a donation-free period of > 5 weeks and in 40 whole blood donors who never undergoing plateletpheresis after a donation-free period of > 6 months. The results showed that the TPO levels was significantly lower in frequent platelet donors than in limited platelet donors (P < 0.01) and whole blood donors (P < 0.01). There were no significant differences between three groups in platelet counts, IL-3, IL-6 and NO. These findings suggest that the number of megakarocytes significantly increased in frequent platelet donors.
Adult ; Blood Donors ; Humans ; Interleukin-3 ; blood ; Interleukin-6 ; blood ; Megakaryocytes ; cytology ; Platelet Count ; Plateletpheresis ; adverse effects ; Thrombopoiesis ; Thrombopoietin ; blood

OBJECTIVETo evaluate the impact of recombinant human thrombopoietin (rhTPO) on short-term response of immunosuppressive therapy (IST) in patients with newly diagnosed acquired severe aplastic anemia (SAA).

METHODSThe clinical data of forty adult acquired SAA patients, who treated with IST combined with rhTPO, were retrospective analyzed and the hematologic recovery were compared with patients by the IST alone during the same period. The factors affecting the short-term response were also analyzed.

RESULTSAt 3 months after IST, both the total response rate and CR+GPR rate in rhTPO group were much higher than those in control group (75.0% vs 50.0%, P=0.022; and 17.5% vs 2.5%, P=0.025). At 6 months after IST, there was no difference of total hematologic response rate in rhTPO group and control group (77.5% vs 57.5%, P=0.058), while the CR+GPR rate was still higher in rhTPO group (45.0% vs 22.5%, P=0.033). The median time of platelet transfusion independence was much shorter in rhTPO group [33(0-90) vs 53(0-75) d, P=0.019]. Patients in rhTPO group needed less platelets transfusion support. The median platelet count in rhTPO group was 29(4-95)×10⁹/L at 3 months after IST, which was much higher than that in control group [29(4-95)×10⁹/L, P=0.006]. There was no significant difference regarding overall survival between the two groups (100.0% vs 91.0%, P=0.276).

CONCLUSIONrhTPO is effective in promoting platelet recovery and improving the hematopoietic response for SAA patients with IST.

Anemia, Aplastic ; Blood Platelets ; Humans ; Immunosuppression ; Platelet Count ; Platelet Transfusion ; Recombinant Proteins ; Retrospective Studies ; Thrombopoietin

OBJECTIVE: To compare the effects of artificial liver treatment with double plasma molecular adsorption system(DPMAS) mode and traditional plasma exchange (PE) mode on platelets in patients, and to evaluate the clinical efficacy of recombinent human thrombopoietin (rhTPO) in the treatment of thrombocytopenia. METHODS: A total of fifteen patients undergoing artificial liver with DPMAS model admitted to the Fifth Affiliated Hospital of Guangzhou Medical University from January 2018 to November 2020 were selected and included in the DPMAS group, and another 15 patients receiving PE were selected and included in the PE group. The improvement of clinical symptoms, such as fatigue, jaundice, oliguria, edema, etc. before and after artificial liver treatment was compared between the two groups, and the trend of blood routine (especially platelet), coagulation function and other indexes before and after treatment were compared between the two groups. The use of rhTPO and the number of platelets were recorded during treatment. RESULTS: The improvement rate of clinical symptoms in DPMAS group was 86.67%, which was higher than that in PE group, but the difference was not statistically significant (P>0.05). There was no statistical significance in the outcome of the two groups within 90 days (P>0.05). There was no significant difference in white blood cell (WBC) and hemoglobin (HB) between the two groups after treatment (P>0.05). However, the level of platelet(PLT) in DPMAS group was significantly lower than that before treatment (P < 0.05), and was significantly lower than that in PE group (P < 0.05). After treatment, the international normalized ratio (INR) level in PE group was significantly improved (P < 0.05), but there was no significant difference in the INR level in DPMAS group (P>0.05). The patients in the DPMAS group received an average of (8.2±3.1) doses of rhTPO and (1.5±0.3) IU of platelet transfusions during hospitalization. In DMPAS group, platelets increased significantly after infusion of terbium. CONCLUSION Compared with PE mode, the artificial liver with DPMAS mode can reduce platelet levels in patients, but the application of rhTPO can stimulate platelet regeneration and increase platelet levels in the patients, thereby reducing the risk of bleeding due to platelet hypoplasia.
Blood Platelets ; Humans ; Liver, Artificial ; Plasma Exchange ; Recombinant Proteins ; Thrombocytopenia/therapy* ; Thrombopoietin

Adolescent ; Adult ; Aged ; Female ; Hepatitis, Chronic ; blood ; complications ; Humans ; Male ; Middle Aged ; Thrombocytopenia ; blood ; etiology ; Thrombopoietin ; blood

To clarify the thrombopoietin (TPO) production in patients with end-stage liver cirrhosis and uremia under hemodialysis, plasma TPO levels in patients with liver cirrhosis (n = 15), uremia under hemodialysis (n = 20) and healthy controls (n = 40) were measured by using a sandwich enzyme linked immunosorbent assay. Relationship between megakaryocytopoiesis and plasma TPO levels was analysed by linear regression. The results showed that the mean plasma TPO concentration in the uremic patients was significantly lower than that in the healthy volunteers, whereas plasma TPO level in end-stage liver cirrhosis was not significantly different from that of normal controls; plasma TPO levels in liver cirrhosis and uremic patients did not significantly influence megakaryocytopoiesis. It is concluded that end-stage liver cirrhosis patients maintained normal plasma TPO levels, but the production of TPO was significantly reduced in renal failure patients. Thrombocytopenia in liver cirrhosis appears to be not related to plasma TPO levels.
Adult ; Aged ; Aged, 80 and over ; Female ; Humans ; Liver Cirrhosis ; blood ; Male ; Middle Aged ; Thrombopoiesis ; Thrombopoietin ; blood ; Uremia ; blood

OBJECTIVETo determine the reason of thrombocytopenia in patients with liver cirrhosis, we studied the relationship among platelet counts, serum thrombopoietin (TPO) level and spleen index.

METHODSSerum TPO, platelet counts and spleen index were measured in 71 cirrhotic patients. TPO was measured with ELISA method, spleen index were measured on ultrasonography by the same doctor.

RESULTSPlatelet counts in patients with cirrhosis were lower than that of healthy group [(109.20+/-53.39) vs (169.63+/-26.60) x 10(12)/L, P<0.05]. Serum thrombopoietin level in patients with cirrhosis was similar to that of healthy group [(436.42+/-258.97) vs (412.63+/-132.80) pg/ml, P>0.05]. However, serum thrombopoietin level decreased as liver disease aggravated, [(526.13+/-317.44) pg/ml in Child-Pugh grade A, (445.22+/-214.90) pg/ml in grade B and (311.45+/-182.66) pg/ml in grade C, grade A vs. Grade C, P<0.05]. However, decline in platelet counts was accompanied with incline in spleen index coordinately. 35 of 71 cirrhotic patients had normal platelet counts whereas 36 of them had thrombocytopenia. Thrombopoietin levels were higher in non-thrombocytopenia group than in thrombocytopenia group [(529.43+/-282.64) vs. (351.27+/-228.25)pg/ml, P<0.01]; but spleen index of two groups showed no difference [(29.65+/-12.00) vs. (36.35+/-12.68) cm2, P>0.05]. Correlation was found between thrombopoietin level and platelet counts (r=0.252, P=0.025); no correlation was found between spleen index and platelet counts (r=-0.238, P=0.062).

CONCLUSIONThe decline serum TPO levels might play an important role for thrombocytopenia in patients with liver cirrhosis.

Adult ; Female ; Humans ; Liver Cirrhosis ; blood ; pathology ; Male ; Middle Aged ; Platelet Count ; Portal Vein ; pathology ; Spleen ; pathology ; Thrombopoietin ; blood

OBJECTIVETo explore the pathogenesis of thrombocytopenia in viral hepatitis.

METHODS84 viral hepatitis patients and 20 healthy controls were divided into three groups: Group A: 48 viral hepatitis patients with thrombocytopenia; Group B: 36 viral hepatitis patients with normal platelet count; and Group C: 20 healthy controls. Serum thrombopoietin (TPO) levels were measured in all subjects by enzyme linked immunosorbent assay. The levels of PAIg, PAIgG, PAIgA, PAIgM were detected in all subjects by flow cytometry. Spleen size was assessed in all subjects by abdominal color ultrasound B Scan. Bone marrow cells were examined in 74 subjects with bone marrow punctures.

RESULTSSerum thrombopoietin level was lower in group A than in group C and in group B. Serum TPO levels were correlated with platelet counts in the patients with advanced liver diseases. PAIg, PAIgG levels were significantly higher in group A than in group B and in group C. An inverse correlation was found between platelet counts and PAIg levels. An inverse correlation was also observed between platelet counts and PAIgG levels. The incidence of splenomegaly was significantly higher in group A (77.1%) than in group B (47.2%), while group C had no splenomegaly. An inverse correlation between spleen size and platelet count was observed (r = -0.581). There were 4 patients in group A with hypoplasia of bone marrow karyocytes, but there were no such cases in groups B and C.

CONCLUSIONSTPO level decreasing in patients with severe liver function impairments correlates with thrombocytopenia in advanced liver diseases. Autoimmune mechanism mediated by PAIg may play an important role in thrombocytopenia associated with viral hepatitis. Splenomegaly is the influencing factor leading to thrombocytopenia in viral hepatitis. Patients with chronic liver diseases had bone marrow depression, which may be a factor inducing thrombocytopenia in patients with viral hepatitis.

Adolescent ; Adult ; Aged ; Female ; Hepatitis, Viral, Human ; blood ; complications ; Humans ; Male ; Middle Aged ; Splenomegaly ; etiology ; Thrombocytopenia ; etiology ; Thrombopoietin ; blood

Animals ; Blood Coagulation ; drug effects ; Blood Platelets ; drug effects ; Female ; Haplorhini ; Humans ; Interleukin-11 ; pharmacology ; Male ; Platelet Count ; Thrombopoietin ; pharmacology