BACKGROUND During cirrhosis,the liver is impaired and unable to synthesize and clear thrombopoietin properly.At the same time,the spleen assumes the function of hemofiltration and storage due to liver dysfunction,resu...BACKGROUND During cirrhosis,the liver is impaired and unable to synthesize and clear thrombopoietin properly.At the same time,the spleen assumes the function of hemofiltration and storage due to liver dysfunction,resulting in hypersplenism and excessive removal of platelets in the spleen,further reducing platelet count.When liver function is decompensated in cirrhotic patients,the decrease of thrombopoietin(TPO)synthesis is the main reason for the decrease of new platelet production.This change of TPO leads to thrombocytopenia and bleeding tendency in cirrhotic patients with hypersplenism.AIM To investigate the clinical efficacy of recombinant human TPO(rhTPO)in the treatment of perioperative thrombocytopenia during liver transplantation in cirrhotic mice with hypersplenism.METHODS C57BL/6J mice and TPO receptor-deficient mice were used to establish models of cirrhosis with hypersplenism.Subsequently,these mice underwent orthotopic liver transplantation(OLT).The mice in the experimental group were given rhTPO treatment for 3 consecutive days before surgery and 5 consecutive days after surgery,while the mice in the control group received the same dose of saline at the same frequency.Differences in liver function and platelet counts were determined between the experimental and control groups.Enzyme-linked immunosorbent assay was used to assess the expression of TPO and TPO receptor(c-Mpl)in the blood.RESULTS Preoperative administration of rhTPO significantly improved peri-OLT thrombocytopenia in mice with cirrhosis and hypersplenism.Blocking the expression of TPO receptors exacerbated peri-OLT thrombocytopenia.The concentration of TPO decreased while the concentration of c-Mpl increased in compensation in the mouse model of cirrhosis with hypersplenism.TPO pre-treatment significantly increased the postoperative TPO concentration in mice,which in turn led to a decrease in the c-Mpl concentration.TPO pre-treatment also significantly enhanced the Janus kinase(Jak)/signal transducers and activators of transcription pathway protein expressions in bone marrow stem cells of the C57BL/6J mice.Moreover,the administration of TPO,both before and after surgery,regulated the levels of biochemical indicators,such as alanine aminotransferase,alkaline phosphatase,and aspartate aminotransferase in the C57BL/6J mice.CONCLUSION Pre-treatment with TPO not only exhibited therapeutic effects on perioperative thrombocytopenia in the mice with cirrhosis and hypersplenism,who underwent liver transplantation but also significantly enhanced the perioperative liver function.展开更多
Objective:To study the regulation of trombinol on thrombopoietin,an essential regulator of thrombocyte production.Methods:Effect of trombinol on thrombopoietin regulation was evaluated at the m RNA and protein levels ...Objective:To study the regulation of trombinol on thrombopoietin,an essential regulator of thrombocyte production.Methods:Effect of trombinol on thrombopoietin regulation was evaluated at the m RNA and protein levels in human hepatoma Hep G2 cells.The m RNA expressions were revealed by PCR and real-time PCR,while the protein expressions were analyzed using western blotting and human ELISA kit.Statistical differences between the test were determined by student's t-test with P < 0.05 was considered statistically significant.Results:Trombinol significantly increased the expression of thrombopoietin at the level of m RNA and protein secretion in Hep G2 cell lines.Trombinol with the concentration of15 mg/m L,positively induces 2.5-fold of thrombopoietin expression.Up-regulation of GABP,a transcription factor of thrombopoietin,is suggested to be involved in cellular regulatory mechanisms of trombinol.Here,our result shows convincing evidence that trombinol affects the thrombopoietin productions in vitro.This molecular explanation of thrombopoietin's stimulating function is in line with the traditional use of Psidium guajava for treatment of diseases involving thrombocytopenia.Conclusions:Thrombopoietin stimulating function of trombinol could be potentially considered as one of alternative treatment for thrombocytopenia-related cases,including post chemotherapy shock,dengue fever and liver failure.展开更多
BACKGROUND Chronic liver disease(CLD)related thrombocytopenia increases the risk of bleeding and poor prognosis.Many liver disease patients require invasive procedures or surgeries,such as liver biopsy or endoscopic v...BACKGROUND Chronic liver disease(CLD)related thrombocytopenia increases the risk of bleeding and poor prognosis.Many liver disease patients require invasive procedures or surgeries,such as liver biopsy or endoscopic variceal ligation,and most of them have lower platelet counts,which could aggravate the risk of bleeding due to liver dysfunction and coagulation disorders.Unfortunately,there is no defined treatment modality for CLD-induced thrombocytopenia.Recombinant human thrombopoietin(rhTPO)is commonly used to treat primary immune thrombocytopenic purpura and thrombocytopenia caused by solid tumor chemotherapy;however,there are few reports on the use of rhTPO in the treatment of CLD-related thrombocytopenia.AIM To evaluate the efficacy of rhTPO in the treatment of patients with CLDassociated thrombocytopenia undergoing invasive procedures.METHODS All analyses were based on the retrospective collection of clinical data of patients with CLD who were treated in the Department of Infectious Diseases at The First Affiliated Hospital of Soochow University between June 2020 and December 2021.Fifty-nine male and 41 female patients with liver disease were enrolled in this study to assess the changes in platelet counts and parameters before and after the use of rhTPO for thrombocytopenia.Adverse events related to treatment,such as bleeding,thrombosis,and disseminated intravascular coagulation,were also investigated.RESULTS Among the enrolled patients,78(78%)showed a platelet count increase after rhTPO use,while 22(22%)showed no significant change in platelet count.The mean platelet count after rhTPO treatment in all patients was 101.53±81.81×10^(9)/L,which was significantly improved compared to that at baseline(42.88±16.72×10^(9)/L),and this difference was statistically significant(P<0.001).In addition,patients were further divided into three subgroups according to their baseline platelet counts(<30×10^(9)/L,30-50×10^(9)/L,>50×10^(9)/L).Subgroup analyses showed that the median platelet counts after treatment were significantly higher(P<0.001,all).Ninety(90%)patients did not require platelet transfusion partially due to an increase in platelet count after treatment with rhTPO.No serious adverse events related to rhTPO treatment were observed.Overall,rhTPO demonstrated good clinical efficacy for treating CLD-associated thrombocytopenia.CONCLUSION rhTPO can improve platelet count,reduce the risk of bleeding,and decrease the platelet transfusion rate,which may promote the safety of invasive procedures and improve overall survival of patients with CLD.展开更多
BACKGROUND： Previous studies have reported a neurotrophin-like motif in the N-terminal receptor binding region of the thrombopoietin （TPO） molecule, and have described localization of TPO and TPO receptor in the br...BACKGROUND： Previous studies have reported a neurotrophin-like motif in the N-terminal receptor binding region of the thrombopoietin （TPO） molecule, and have described localization of TPO and TPO receptor in the brain. Therefore, it is believed that TPO may be involved in regulation of neurogenesis. OBJECTIVE： To validate the effect of TPO on trans-differentiation, or differentiation from hematopoietic stem cells （HSCs） to neural stem cells （NSCs）. DESIGN, TIME AND SETTING： Comparative studies were performed from March 2004 to April 2007 at the Department of Experimental Medicine, Northern Hospital, and the Department of Immunology, Fourth Military Medical University of Chinese PLA. MATERIALS： Human fetal liver （FL） was obtained from fetuses after water-balloon abortion. Gestational age ranged from 16 to 20 weeks. The study was approved by the Institutional Review Board and Ethics Committee of the Northern Hospital. TPO was kindly provided by Genentech Inc （USA）. Iscove＇s Modified Dulbecco＇s Medium （IMDM） and neurobasalTM medium were purchased from Invitrogen （USA）. MACS CD34 multisort kit was purchased from Miltenyi Biotec （Germany）. METHODS： CD34^＋ cells were isolated from human FL mononuclear cells using MACS CD34 multisort kit and cultured at 1 × 10^5/mL in IMDM, containing TPO for 60 days with weekly changes of half of the medium. After culturing for 30 and 60 days, the TPO-induced cells were resuspended in neurobasalTM medium containing 10% fetal brain extracts and plated in an 8-well BIOCOAT poly-D-Lysine Culture Slide and cultured for another 7 days. MAIN OUTCOME MEASURES： Cell number, viability, phenotype and expression of hemopoiesis-related and neurogenesis-related proteins were examined by trypan blue exclusion with hemocytometer, immunoblot, immunocytochemistry and flow cytometry. RESULTS： After 60 days of induction with TPO, the cell number increased by 4.6-fold compared to the initial culture. Although the proportion of the cells expressing the hemopoietic stem cell associated antigen （CD34） decreased steadily, both proportions of the cultured FL-derived CD34^＋cells expressing CD41a and CD61 remained unchanged, which still accounted for 10%. Noticeably, the proportions of the cells expressing nestin and epidermal growth factor receptor increased significantly （both 〉 50%）, whereas the expression of more mature neural or glial proteins [microtubule-associated protein-2 （MAP2）, glial fibrillary acidic protein （GFAP）, oligodendrocyte marker 04 （04）] markers on the cultured fetal liver derived-CD34^＋ cells were at lower levels. After another 7 days incubation in neurobasalTM medium, these TPO-induced cells formed neurospheres, which were labeled with nestin, and differentiated into cells with morphological characteristics of neurons, astrocytes and oligodendrocytes, which were labeled with MAP-2, GFAE and 04, respectively. CONCLUSION： TPO can induce FL-derived HSCs to differentiate or trans-differentiate into NSCs and its progenitors.展开更多
Objective To demonstrate whether heparin could act synergically with thrombopoietin (TPO) instimulating megakaryocytopoiesis and thrombopoiesis. Methods Megakaryocytic leukemia cell line M- 07e,human cord blood CD34+ ...Objective To demonstrate whether heparin could act synergically with thrombopoietin (TPO) instimulating megakaryocytopoiesis and thrombopoiesis. Methods Megakaryocytic leukemia cell line M- 07e,human cord blood CD34+ cells and Balb/c mice were used for studies. The effectS of hoparin and/or TPO onmegakaryocytopoiesis and thrombopoiesis were studied by [ 3H ] - TdR incoroperation assay, CFU- MK plasmicsemi- solid culture and experiment in Balb/c mice in vivo. In addition, M- 07e cells were used as targets tofurther investigate the possible molecular mechanism by which heparin might act synergically with TPO throughNorthern and Western blot analyses. Results Heparin can act synergically with TPO in stimulating theproliferation of leukemia cell line M- 07e, growth of CFU- MK from human cord blood CD34+ cells andmegakaryocytopoiesis and thrombopoiesis in vivo in mice, possibly by antagonizing downregulation of c- mplexpression by TPO at the level of mRNA transcription, and increasing the phosphotyrosine content Of Jak2,triggered by TPO. Conclusion Heparin participated in positive regulation of megakaryocytopoiesis andthrombopoiesis by enhancing the megakaryocytopoietic activities of TPO, and the mechanism of which might beinvolved in the modification of the molecules c- mpl and Jak2 on the way of signal transduction triggered by TPO.展开更多
BACKGROUND Thrombopoietin(TPO)is a primary regulator of thrombopoiesis in physiological conditions.TPO,in combination with its specific cytokine receptor c-Mpl,drives platelet production by inducing the proliferation ...BACKGROUND Thrombopoietin(TPO)is a primary regulator of thrombopoiesis in physiological conditions.TPO,in combination with its specific cytokine receptor c-Mpl,drives platelet production by inducing the proliferation and differentiation of megakaryocytes.However,the role of TPO in sepsis is not well determined.The elevated levels of TPO are often accompanied by a decrease of platelet count(PLT)in systemic infected conditions,which is contrary to the view that TPO promotes platelet production under physiological conditions.In addition,whether TPO mediates organ damage in sepsis remains controversial.AIM To explore the relationships between TPO and inflammatory factors,platelet indices,and thrombotic indicators in sepsis.METHODS A total of 90 patients with sepsis diagnosed and treated at the emergency medicine department of The First People’s Hospital of Foshan between January 2020 and March 2021 were enrolled in this study.In addition,110 patients without sepsis who came to the emergency medicine department were included as controls.Clinical and laboratory parameters including age,gender,TPO,blood cell count in peripheral blood,platelet indices,inflammatory factors such as high-sensitivity Creactive protein(hs-CRP),interleukin(IL)-21,and IL-6,organ damage indicators,and thrombotic indicators were collected and analyzed by using various statistical approaches.RESULTS The results showed that the TPO levels were higher in the sepsis group than in controls[86.45(30.55,193.1)vs 12.45(0.64,46.09)pg/mL,P<0.001],but PLT was lower(P<0.001).Multivariable analysis showed that white blood cell count(WBC)[odds ratio(OR)=1.32;95%confidence interval(CI):1.01-1.722;P=0.044],TPO(OR=1.02;95%CI:1.01-1.04;P=0.009),IL-21(OR=1.02;95%CI:1.00-1.03;P=0.019),troponin I(OR=55.20;95%CI:5.69-535.90;P=0.001),and prothrombin time(PT)(OR=2.24;95%CI:1.10-4.55;P=0.027)were independent risk factors associated with sepsis.TPO levels were positively correlated with IL-21,IL-6,hs-CRP,creatinine,D-dimer,PT,activated prothrombin time,international normalized ratio,fibrinogen,WBC count,and neutrophil count,and negatively correlated with PLT,thrombin time,red blood cell count,and hemoglobin concentration(P<0.05).Receiver operating characteristic analysis showed that TPO had fair predictive value in distinguishing septic patients and non-septic patients(the area under the curve:0.788;95%CI:0.723-0.852;P<0.001).With an optimized cutoff value(28.51 pg/mL),TPO had the highest sensitivity(79%)and specificity(65%).CONCLUSION TPO levels are independently associated with sepsis.High TPO levels and low PLT suggest that TPO might be an acute-phase response protein in patients with infection.展开更多
Thrombocytopenia is a multifactorial disorder that is common in patients with chronic liver disease(CLD),leading to challenging perioperative planning.As thrombocytopenia in CLD is associated with thrombopoietin(TPO)d...Thrombocytopenia is a multifactorial disorder that is common in patients with chronic liver disease(CLD),leading to challenging perioperative planning.As thrombocytopenia in CLD is associated with thrombopoietin(TPO)deficiency,the use of TPO-receptor agonists(TPO-RAs)to increase platelet counts is a promising approach.This has led to the development of various TPO-RAs,including romiplostim,eltrombopag,avatrombopag,and lusutrombopag.Of these,only avatrombopag and lusutrombopag are approved by the United States Food and Drug Administration for the perioperative treatment of thrombocytopenia in patients with CLD.Platelet transfusion is commonly used for the clinical management of thrombocytopenia in patients with CLD undergoing invasive procedures.However,the limitations and possible risks of transfusion,including short duration of efficacy,development of antiplatelet antibodies,risk of infections and such complications as transfusion-related acute lung injury or circulatory overload,and possibility of refractoriness,limit its use.Moreover,there is no consensus among guidelines as to the platelet count at which transfusions are indicated.Results from studies using TPO-RAs perioperatively in patients with thrombocytopenia and CLD are promising and provide an alternative to platelet transfusions in the pre-and post-operative setting.These TPO-RAs are the subject of this review,with focus on their use in the perioperative setting in patients with thrombocytopenia,associated supporting clinical trials,efficacy and safety data,and their use with respect to platelet transfusions.展开更多
Background The management of patients with refractory immune thrombocytopenia （ITP） is challenging, as there is no standard treatment option. The aim of this study was to investigate the efficacy of recombinant huma...Background The management of patients with refractory immune thrombocytopenia （ITP） is challenging, as there is no standard treatment option. The aim of this study was to investigate the efficacy of recombinant human thrombopoietin （rhTPO） in combination with cyclosporin A （CsA） for the management of patients with corticosteroid-resistant primary ITP.展开更多
Thrombopoietin (TPO) functions as a regulator of megakaryocytes in their differentiation and maturation, and is a candidate pharmaceutical for the curing of thrombocytopenia. Erythropoietin (EPO) is a hematopoietic cy...Thrombopoietin (TPO) functions as a regulator of megakaryocytes in their differentiation and maturation, and is a candidate pharmaceutical for the curing of thrombocytopenia. Erythropoietin (EPO) is a hematopoietic cytokine that regulates the level of red blood cell. It is widely used in renal anemia and tumor associated anemia, and is proved to be safe and effective. In order to study the possibility of using TPO EPO fusion protein for the curing of anemia and thrombocytopenia induced by high dose chemotherapy, a fusion gene is constructed by linking TPO N terminal 153 peptide and EPO mature peptide coding region. The fusion gene is expressed in mammalian cells, revealing that the expression product can support the growth of TPO responsive Ba/F3 mpl cells and EPO dependent Bet 2 cells in the absence of any other stimulating cytokine. It also stimulates the formation of erythroid colonies and megakaryocytic colonies in semi solid bone marrow cultures. These results indicate that the fusion protein has both the in vitro activities of TPO and EPO. The preliminary in vivo experiment reveals that the TPO EPO fusion protein containing cell supernatant raises the platelet level by 37% in mice, while its function on erythroid hematopoiesis remains to be determined. These results indicate that the construction of TPO EPO fusion protein and the further study of its use in high dose chemotherapy are展开更多
Dendritic cells （DCs） are immune cells specialized to capture, process and present antigen to T cells in order to initiate an appropriate adaptive immune response. The study of mouse DC has revealed a heterogeneous ...Dendritic cells （DCs） are immune cells specialized to capture, process and present antigen to T cells in order to initiate an appropriate adaptive immune response. The study of mouse DC has revealed a heterogeneous population of cells that differ in their development, surface phenotype and function. The study of human blood and spleen has shown the presence of two subsets of conventional DC including the CDlb/c＋ and CD141＋CLEC9A＋ conventional DC （cDC） and a plasmacytoid DC （pDC） that is CD304＋CD123＋. Studies on these subpopulations have revealed phenotypic and functional differences that are similar to those described in the mouse. In this study, the three DC subsets have been generated in vitrofrom human CD34＋ precursors in the presence of fins-like tyrosine kinase 3 ligand （FIt3L） and thrombopoietin （TPO）. The DC subsets so generated, including the CDlb/c＋ and CLEC9A＋ cDCs and CD123 ＋ pDCs, were largely similar to their blood and spleen counterparts with respect to surface phenotype, toll-like receptor and transcription factor expression, capacity to stimulate T cells, cytokine secretion and cross-presentation of antigens. This system may be utilized to study aspects of DC development and function not possible in vivo.展开更多
基金All procedures involving animals were reviewed and approved by the Tianjin Tiancheng New Drug Evaluation Co.,Ltd(Approval No.2023041701).
文摘BACKGROUND During cirrhosis,the liver is impaired and unable to synthesize and clear thrombopoietin properly.At the same time,the spleen assumes the function of hemofiltration and storage due to liver dysfunction,resulting in hypersplenism and excessive removal of platelets in the spleen,further reducing platelet count.When liver function is decompensated in cirrhotic patients,the decrease of thrombopoietin(TPO)synthesis is the main reason for the decrease of new platelet production.This change of TPO leads to thrombocytopenia and bleeding tendency in cirrhotic patients with hypersplenism.AIM To investigate the clinical efficacy of recombinant human TPO(rhTPO)in the treatment of perioperative thrombocytopenia during liver transplantation in cirrhotic mice with hypersplenism.METHODS C57BL/6J mice and TPO receptor-deficient mice were used to establish models of cirrhosis with hypersplenism.Subsequently,these mice underwent orthotopic liver transplantation(OLT).The mice in the experimental group were given rhTPO treatment for 3 consecutive days before surgery and 5 consecutive days after surgery,while the mice in the control group received the same dose of saline at the same frequency.Differences in liver function and platelet counts were determined between the experimental and control groups.Enzyme-linked immunosorbent assay was used to assess the expression of TPO and TPO receptor(c-Mpl)in the blood.RESULTS Preoperative administration of rhTPO significantly improved peri-OLT thrombocytopenia in mice with cirrhosis and hypersplenism.Blocking the expression of TPO receptors exacerbated peri-OLT thrombocytopenia.The concentration of TPO decreased while the concentration of c-Mpl increased in compensation in the mouse model of cirrhosis with hypersplenism.TPO pre-treatment significantly increased the postoperative TPO concentration in mice,which in turn led to a decrease in the c-Mpl concentration.TPO pre-treatment also significantly enhanced the Janus kinase(Jak)/signal transducers and activators of transcription pathway protein expressions in bone marrow stem cells of the C57BL/6J mice.Moreover,the administration of TPO,both before and after surgery,regulated the levels of biochemical indicators,such as alanine aminotransferase,alkaline phosphatase,and aspartate aminotransferase in the C57BL/6J mice.CONCLUSION Pre-treatment with TPO not only exhibited therapeutic effects on perioperative thrombocytopenia in the mice with cirrhosis and hypersplenism,who underwent liver transplantation but also significantly enhanced the perioperative liver function.
文摘Objective:To study the regulation of trombinol on thrombopoietin,an essential regulator of thrombocyte production.Methods:Effect of trombinol on thrombopoietin regulation was evaluated at the m RNA and protein levels in human hepatoma Hep G2 cells.The m RNA expressions were revealed by PCR and real-time PCR,while the protein expressions were analyzed using western blotting and human ELISA kit.Statistical differences between the test were determined by student's t-test with P < 0.05 was considered statistically significant.Results:Trombinol significantly increased the expression of thrombopoietin at the level of m RNA and protein secretion in Hep G2 cell lines.Trombinol with the concentration of15 mg/m L,positively induces 2.5-fold of thrombopoietin expression.Up-regulation of GABP,a transcription factor of thrombopoietin,is suggested to be involved in cellular regulatory mechanisms of trombinol.Here,our result shows convincing evidence that trombinol affects the thrombopoietin productions in vitro.This molecular explanation of thrombopoietin's stimulating function is in line with the traditional use of Psidium guajava for treatment of diseases involving thrombocytopenia.Conclusions:Thrombopoietin stimulating function of trombinol could be potentially considered as one of alternative treatment for thrombocytopenia-related cases,including post chemotherapy shock,dengue fever and liver failure.
基金Supported by the Science and Technology Development Plan of Suzhou,Jiangsu Province,China,No.SYS2020009.
文摘BACKGROUND Chronic liver disease(CLD)related thrombocytopenia increases the risk of bleeding and poor prognosis.Many liver disease patients require invasive procedures or surgeries,such as liver biopsy or endoscopic variceal ligation,and most of them have lower platelet counts,which could aggravate the risk of bleeding due to liver dysfunction and coagulation disorders.Unfortunately,there is no defined treatment modality for CLD-induced thrombocytopenia.Recombinant human thrombopoietin(rhTPO)is commonly used to treat primary immune thrombocytopenic purpura and thrombocytopenia caused by solid tumor chemotherapy;however,there are few reports on the use of rhTPO in the treatment of CLD-related thrombocytopenia.AIM To evaluate the efficacy of rhTPO in the treatment of patients with CLDassociated thrombocytopenia undergoing invasive procedures.METHODS All analyses were based on the retrospective collection of clinical data of patients with CLD who were treated in the Department of Infectious Diseases at The First Affiliated Hospital of Soochow University between June 2020 and December 2021.Fifty-nine male and 41 female patients with liver disease were enrolled in this study to assess the changes in platelet counts and parameters before and after the use of rhTPO for thrombocytopenia.Adverse events related to treatment,such as bleeding,thrombosis,and disseminated intravascular coagulation,were also investigated.RESULTS Among the enrolled patients,78(78%)showed a platelet count increase after rhTPO use,while 22(22%)showed no significant change in platelet count.The mean platelet count after rhTPO treatment in all patients was 101.53±81.81×10^(9)/L,which was significantly improved compared to that at baseline(42.88±16.72×10^(9)/L),and this difference was statistically significant(P<0.001).In addition,patients were further divided into three subgroups according to their baseline platelet counts(<30×10^(9)/L,30-50×10^(9)/L,>50×10^(9)/L).Subgroup analyses showed that the median platelet counts after treatment were significantly higher(P<0.001,all).Ninety(90%)patients did not require platelet transfusion partially due to an increase in platelet count after treatment with rhTPO.No serious adverse events related to rhTPO treatment were observed.Overall,rhTPO demonstrated good clinical efficacy for treating CLD-associated thrombocytopenia.CONCLUSION rhTPO can improve platelet count,reduce the risk of bleeding,and decrease the platelet transfusion rate,which may promote the safety of invasive procedures and improve overall survival of patients with CLD.
基金National Key Basic Research Program of China, No. 2001CB510004the National Natural Science Foundation of China,No.30030130
文摘BACKGROUND： Previous studies have reported a neurotrophin-like motif in the N-terminal receptor binding region of the thrombopoietin （TPO） molecule, and have described localization of TPO and TPO receptor in the brain. Therefore, it is believed that TPO may be involved in regulation of neurogenesis. OBJECTIVE： To validate the effect of TPO on trans-differentiation, or differentiation from hematopoietic stem cells （HSCs） to neural stem cells （NSCs）. DESIGN, TIME AND SETTING： Comparative studies were performed from March 2004 to April 2007 at the Department of Experimental Medicine, Northern Hospital, and the Department of Immunology, Fourth Military Medical University of Chinese PLA. MATERIALS： Human fetal liver （FL） was obtained from fetuses after water-balloon abortion. Gestational age ranged from 16 to 20 weeks. The study was approved by the Institutional Review Board and Ethics Committee of the Northern Hospital. TPO was kindly provided by Genentech Inc （USA）. Iscove＇s Modified Dulbecco＇s Medium （IMDM） and neurobasalTM medium were purchased from Invitrogen （USA）. MACS CD34 multisort kit was purchased from Miltenyi Biotec （Germany）. METHODS： CD34^＋ cells were isolated from human FL mononuclear cells using MACS CD34 multisort kit and cultured at 1 × 10^5/mL in IMDM, containing TPO for 60 days with weekly changes of half of the medium. After culturing for 30 and 60 days, the TPO-induced cells were resuspended in neurobasalTM medium containing 10% fetal brain extracts and plated in an 8-well BIOCOAT poly-D-Lysine Culture Slide and cultured for another 7 days. MAIN OUTCOME MEASURES： Cell number, viability, phenotype and expression of hemopoiesis-related and neurogenesis-related proteins were examined by trypan blue exclusion with hemocytometer, immunoblot, immunocytochemistry and flow cytometry. RESULTS： After 60 days of induction with TPO, the cell number increased by 4.6-fold compared to the initial culture. Although the proportion of the cells expressing the hemopoietic stem cell associated antigen （CD34） decreased steadily, both proportions of the cultured FL-derived CD34^＋cells expressing CD41a and CD61 remained unchanged, which still accounted for 10%. Noticeably, the proportions of the cells expressing nestin and epidermal growth factor receptor increased significantly （both 〉 50%）, whereas the expression of more mature neural or glial proteins [microtubule-associated protein-2 （MAP2）, glial fibrillary acidic protein （GFAP）, oligodendrocyte marker 04 （04）] markers on the cultured fetal liver derived-CD34^＋ cells were at lower levels. After another 7 days incubation in neurobasalTM medium, these TPO-induced cells formed neurospheres, which were labeled with nestin, and differentiated into cells with morphological characteristics of neurons, astrocytes and oligodendrocytes, which were labeled with MAP-2, GFAE and 04, respectively. CONCLUSION： TPO can induce FL-derived HSCs to differentiate or trans-differentiate into NSCs and its progenitors.
文摘Objective To demonstrate whether heparin could act synergically with thrombopoietin (TPO) instimulating megakaryocytopoiesis and thrombopoiesis. Methods Megakaryocytic leukemia cell line M- 07e,human cord blood CD34+ cells and Balb/c mice were used for studies. The effectS of hoparin and/or TPO onmegakaryocytopoiesis and thrombopoiesis were studied by [ 3H ] - TdR incoroperation assay, CFU- MK plasmicsemi- solid culture and experiment in Balb/c mice in vivo. In addition, M- 07e cells were used as targets tofurther investigate the possible molecular mechanism by which heparin might act synergically with TPO throughNorthern and Western blot analyses. Results Heparin can act synergically with TPO in stimulating theproliferation of leukemia cell line M- 07e, growth of CFU- MK from human cord blood CD34+ cells andmegakaryocytopoiesis and thrombopoiesis in vivo in mice, possibly by antagonizing downregulation of c- mplexpression by TPO at the level of mRNA transcription, and increasing the phosphotyrosine content Of Jak2,triggered by TPO. Conclusion Heparin participated in positive regulation of megakaryocytopoiesis andthrombopoiesis by enhancing the megakaryocytopoietic activities of TPO, and the mechanism of which might beinvolved in the modification of the molecules c- mpl and Jak2 on the way of signal transduction triggered by TPO.
基金Supported by the Guangdong Province Medical Science and Technology Research Foundation,No.B2014377the Medical Scientific Research Project of Foshan,No.20190036.
文摘BACKGROUND Thrombopoietin(TPO)is a primary regulator of thrombopoiesis in physiological conditions.TPO,in combination with its specific cytokine receptor c-Mpl,drives platelet production by inducing the proliferation and differentiation of megakaryocytes.However,the role of TPO in sepsis is not well determined.The elevated levels of TPO are often accompanied by a decrease of platelet count(PLT)in systemic infected conditions,which is contrary to the view that TPO promotes platelet production under physiological conditions.In addition,whether TPO mediates organ damage in sepsis remains controversial.AIM To explore the relationships between TPO and inflammatory factors,platelet indices,and thrombotic indicators in sepsis.METHODS A total of 90 patients with sepsis diagnosed and treated at the emergency medicine department of The First People’s Hospital of Foshan between January 2020 and March 2021 were enrolled in this study.In addition,110 patients without sepsis who came to the emergency medicine department were included as controls.Clinical and laboratory parameters including age,gender,TPO,blood cell count in peripheral blood,platelet indices,inflammatory factors such as high-sensitivity Creactive protein(hs-CRP),interleukin(IL)-21,and IL-6,organ damage indicators,and thrombotic indicators were collected and analyzed by using various statistical approaches.RESULTS The results showed that the TPO levels were higher in the sepsis group than in controls[86.45(30.55,193.1)vs 12.45(0.64,46.09)pg/mL,P<0.001],but PLT was lower(P<0.001).Multivariable analysis showed that white blood cell count(WBC)[odds ratio(OR)=1.32;95%confidence interval(CI):1.01-1.722;P=0.044],TPO(OR=1.02;95%CI:1.01-1.04;P=0.009),IL-21(OR=1.02;95%CI:1.00-1.03;P=0.019),troponin I(OR=55.20;95%CI:5.69-535.90;P=0.001),and prothrombin time(PT)(OR=2.24;95%CI:1.10-4.55;P=0.027)were independent risk factors associated with sepsis.TPO levels were positively correlated with IL-21,IL-6,hs-CRP,creatinine,D-dimer,PT,activated prothrombin time,international normalized ratio,fibrinogen,WBC count,and neutrophil count,and negatively correlated with PLT,thrombin time,red blood cell count,and hemoglobin concentration(P<0.05).Receiver operating characteristic analysis showed that TPO had fair predictive value in distinguishing septic patients and non-septic patients(the area under the curve:0.788;95%CI:0.723-0.852;P<0.001).With an optimized cutoff value(28.51 pg/mL),TPO had the highest sensitivity(79%)and specificity(65%).CONCLUSION TPO levels are independently associated with sepsis.High TPO levels and low PLT suggest that TPO might be an acute-phase response protein in patients with infection.
文摘Thrombocytopenia is a multifactorial disorder that is common in patients with chronic liver disease(CLD),leading to challenging perioperative planning.As thrombocytopenia in CLD is associated with thrombopoietin(TPO)deficiency,the use of TPO-receptor agonists(TPO-RAs)to increase platelet counts is a promising approach.This has led to the development of various TPO-RAs,including romiplostim,eltrombopag,avatrombopag,and lusutrombopag.Of these,only avatrombopag and lusutrombopag are approved by the United States Food and Drug Administration for the perioperative treatment of thrombocytopenia in patients with CLD.Platelet transfusion is commonly used for the clinical management of thrombocytopenia in patients with CLD undergoing invasive procedures.However,the limitations and possible risks of transfusion,including short duration of efficacy,development of antiplatelet antibodies,risk of infections and such complications as transfusion-related acute lung injury or circulatory overload,and possibility of refractoriness,limit its use.Moreover,there is no consensus among guidelines as to the platelet count at which transfusions are indicated.Results from studies using TPO-RAs perioperatively in patients with thrombocytopenia and CLD are promising and provide an alternative to platelet transfusions in the pre-and post-operative setting.These TPO-RAs are the subject of this review,with focus on their use in the perioperative setting in patients with thrombocytopenia,associated supporting clinical trials,efficacy and safety data,and their use with respect to platelet transfusions.
文摘Background The management of patients with refractory immune thrombocytopenia （ITP） is challenging, as there is no standard treatment option. The aim of this study was to investigate the efficacy of recombinant human thrombopoietin （rhTPO） in combination with cyclosporin A （CsA） for the management of patients with corticosteroid-resistant primary ITP.
文摘Thrombopoietin (TPO) functions as a regulator of megakaryocytes in their differentiation and maturation, and is a candidate pharmaceutical for the curing of thrombocytopenia. Erythropoietin (EPO) is a hematopoietic cytokine that regulates the level of red blood cell. It is widely used in renal anemia and tumor associated anemia, and is proved to be safe and effective. In order to study the possibility of using TPO EPO fusion protein for the curing of anemia and thrombocytopenia induced by high dose chemotherapy, a fusion gene is constructed by linking TPO N terminal 153 peptide and EPO mature peptide coding region. The fusion gene is expressed in mammalian cells, revealing that the expression product can support the growth of TPO responsive Ba/F3 mpl cells and EPO dependent Bet 2 cells in the absence of any other stimulating cytokine. It also stimulates the formation of erythroid colonies and megakaryocytic colonies in semi solid bone marrow cultures. These results indicate that the fusion protein has both the in vitro activities of TPO and EPO. The preliminary in vivo experiment reveals that the TPO EPO fusion protein containing cell supernatant raises the platelet level by 37% in mice, while its function on erythroid hematopoiesis remains to be determined. These results indicate that the construction of TPO EPO fusion protein and the further study of its use in high dose chemotherapy are
文摘Dendritic cells （DCs） are immune cells specialized to capture, process and present antigen to T cells in order to initiate an appropriate adaptive immune response. The study of mouse DC has revealed a heterogeneous population of cells that differ in their development, surface phenotype and function. The study of human blood and spleen has shown the presence of two subsets of conventional DC including the CDlb/c＋ and CD141＋CLEC9A＋ conventional DC （cDC） and a plasmacytoid DC （pDC） that is CD304＋CD123＋. Studies on these subpopulations have revealed phenotypic and functional differences that are similar to those described in the mouse. In this study, the three DC subsets have been generated in vitrofrom human CD34＋ precursors in the presence of fins-like tyrosine kinase 3 ligand （FIt3L） and thrombopoietin （TPO）. The DC subsets so generated, including the CDlb/c＋ and CLEC9A＋ cDCs and CD123 ＋ pDCs, were largely similar to their blood and spleen counterparts with respect to surface phenotype, toll-like receptor and transcription factor expression, capacity to stimulate T cells, cytokine secretion and cross-presentation of antigens. This system may be utilized to study aspects of DC development and function not possible in vivo.
