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Dulmovits BM, Wild KT, Flibotte J, Lambert MP, Kwiatkowski J, Thom CS. Neonatal Thrombocytopenia as a Presenting Finding in de novo Pyruvate Kinase Deficiency. Neonatology 2023; 120:661-665. [PMID: 37473739 PMCID: PMC11027091 DOI: 10.1159/000531242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 05/22/2023] [Indexed: 07/22/2023]
Abstract
Thrombocytopenia is a common laboratory abnormality encountered in critically ill neonates. The broad differential for thrombocytopenia, and its association with potentially severe neonatal pathology, often presents a diagnostic dilemma prompting extensive evaluation. Hemolysis due to red cell enzymopathies is a rare cause of neonatal thrombocytopenia that is typically brief and self-limiting. Here, we present a case of thrombocytopenia, refractory to transfusion, associated with anemia and hyperbilirubinemia in a neonate with pyruvate kinase deficiency (PKD) arising from compound heterozygous PKLR mutations. The nature of the thrombocytopenia in this patient created considerable diagnostic uncertainty, which was ultimately resolved by whole-exome sequencing. This case emphasizes that inherited red cell defects, such as PKD, are important to consider in cases of neonatal thrombocytopenia.
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MESH Headings
- Infant, Newborn
- Humans
- Thrombocytopenia, Neonatal Alloimmune
- Anemia, Hemolytic, Congenital Nonspherocytic/complications
- Anemia, Hemolytic, Congenital Nonspherocytic/diagnosis
- Anemia, Hemolytic, Congenital Nonspherocytic/genetics
- Pyruvate Metabolism, Inborn Errors/diagnosis
- Pyruvate Metabolism, Inborn Errors/genetics
- Pyruvate Metabolism, Inborn Errors/complications
- Pyruvate Kinase/genetics
- Anemia
- Infant, Newborn, Diseases
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Affiliation(s)
- Brian M Dulmovits
- Division of Neonatology, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - K Taylor Wild
- Division of Neonatology, Children’s Hospital of Philadelphia, Philadelphia, PA
- Division of Genetics, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - John Flibotte
- Division of Neonatology, Children’s Hospital of Philadelphia, Philadelphia, PA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Michele P Lambert
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Division of Hematology, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Janet Kwiatkowski
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Division of Hematology, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Christopher S Thom
- Division of Neonatology, Children’s Hospital of Philadelphia, Philadelphia, PA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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2
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Review on the Biogenesis of Platelets in Lungs and Its Alterations in SARS-CoV-2 Infection Patients. J Renin Angiotensin Aldosterone Syst 2023; 2023:7550197. [PMID: 36891250 PMCID: PMC9988383 DOI: 10.1155/2023/7550197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 01/28/2023] [Accepted: 02/08/2023] [Indexed: 03/01/2023] Open
Abstract
Thrombocytes (platelets) are the type of blood cells that are involved in hemostasis, thrombosis, etc. For the conversion of megakaryocytes into thrombocytes, the thrombopoietin (TPO) protein is essential which is encoded by the TPO gene. TPO gene is present in the long arm of chromosome number 3 (3q26). This TPO protein interacts with the c-Mpl receptor, which is present on the outer surface of megakaryocytes. As a result, megakaryocyte breaks into the production of functional thrombocytes. Some of the evidence shows that the megakaryocytes, the precursor of thrombocytes, are seen in the lung's interstitium. This review focuses on the involvement of the lungs in the production of thrombocytes and their mechanism. A lot of findings show that viral diseases, which affect the lungs, cause thrombocytopenia in human beings. One of the notable viral diseases is COVID-19 or severe acute respiratory syndrome caused by SARS-associated coronavirus 2 (SARS-CoV-2). SARS-CoV-2 caused a worldwide alarm in 2019 and a lot of people suffered because of this disease. It mainly targets the lung cells for its replication. To enter the cells, these virus targets the angiotensin-converting enzyme-2 (ACE-2) receptors that are abundantly seen on the surface of the lung cells. Recent reports of COVID-19-affected patients reveal the important fact that these peoples develop thrombocytopenia as a post-COVID condition. This review elaborates on the biogenesis of platelets in the lungs and the alterations of thrombocytes during the COVID-19 infection.
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Mahamid A, Abu-Zaydeh O, Sawaied M, Goldberg N, Haddad R. The Role of Preoperative Platelet-to-Lymphocyte Ratio as a Predictor for Incisional Hernias after Hand-Assisted Laparoscopic Liver Surgery for Metastatic Colorectal Cancer. J Pers Med 2022; 12:jpm12030492. [PMID: 35330491 PMCID: PMC8950596 DOI: 10.3390/jpm12030492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 02/09/2022] [Accepted: 03/17/2022] [Indexed: 02/01/2023] Open
Abstract
(1) Background: Hand-assisted laparoscopic surgery for liver resection is a globally established technique. In this study, we report on the incidence and risk factors for postoperative incisional hernia (IH) after hand-assisted laparoscopic surgery for colorectal liver metastasis. (2) Methods: This was retrospective analysis of 89 consecutive hand-assisted laparoscopic surgery for colorectal liver metastasis. (3) Results: Participants were 39 females and 50 males. Median age was 65 years, and in 63%, the BMI was ≥25. Postoperative complications were encountered in 18% of the patients. Seven patients (7.8%) had postoperative incisional hernia in the hand port site. There was significantly higher incidence of incisional hernia in overweight patients (BMI ≥ 25) (p = 0.04), and in cases with simultaneous liver and colon resection (p = 0.02). In univariant and multivariant analyses, simultaneous liver and colon resection (p = 0.004 and 0.03, respectively), and platelet-to-lymphocyte ratio ≤ 200 (p = 0.03, 0.04, respectively) were both independent risk factors for developing postoperative incisional hernia. (4) Conclusions: Both simultaneous liver and colon resection, and platelet-to-lymphocyte ratio ≤ 200 are independent risk factors for postoperative incisional hernia after hand-assisted laparoscopic surgery for colorectal liver metastasis.
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Affiliation(s)
- Ahmad Mahamid
- Department of Surgery, Carmel Medical Center, Haifa 3436212, Israel; (A.M.); (O.A.-Z.); (M.S.)
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, Haifa 3525433, Israel;
| | - Omar Abu-Zaydeh
- Department of Surgery, Carmel Medical Center, Haifa 3436212, Israel; (A.M.); (O.A.-Z.); (M.S.)
| | - Muneer Sawaied
- Department of Surgery, Carmel Medical Center, Haifa 3436212, Israel; (A.M.); (O.A.-Z.); (M.S.)
| | - Natalia Goldberg
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, Haifa 3525433, Israel;
- Department of Radiology, Carmel Medical Center, Haifa 3436212, Israel
| | - Riad Haddad
- Department of Surgery, Carmel Medical Center, Haifa 3436212, Israel; (A.M.); (O.A.-Z.); (M.S.)
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, Haifa 3525433, Israel;
- Correspondence:
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Nguyen G, Lejeune M, Crichi B, Frere C. Hemostasis testing in patients with liver dysfunction: Advantages and caveats. World J Gastroenterol 2021; 27:7285-7298. [PMID: 34876789 PMCID: PMC8611202 DOI: 10.3748/wjg.v27.i42.7285] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/08/2021] [Accepted: 10/20/2021] [Indexed: 02/06/2023] Open
Abstract
Due to concomitant changes in pro- and anti-coagulant mechanisms, patients with liver dysfunction have a “rebalanced hemostasis”, which can easily be tipped toward either a hypo- or a hypercoagulable phenotype. Clinicians are often faced with the question whether patients with chronic liver disease undergoing invasive procedures or surgery and those having active bleeding require correction of the hemostasis abnormalities. Conventional coagulation screening tests, such as the prothrombin time/international normalized ratio and the activated partial thromboplastin time have been demonstrated to have numerous limitations in these patients and do not predict the risk of bleeding prior to high-risk procedures. The introduction of global coagulation assays, such as viscoelastic testing (VET), has been an important step forward in the assessment of the overall hemostasis profile. A growing body of evidence now suggests that the use of VET might be of significant clinical utility to prevent unnecessary infusion of blood products and to improve outcomes in numerous settings. The present review discusses the advantages and caveats of both conventional and global coagulation assays to assess the risk of bleeding in patients with chronic liver disease as well as the current role of transfusion and hemostatic agents to prevent or manage bleeding.
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Affiliation(s)
- Guillaume Nguyen
- Department of Hematology, Trousseau Hospital, Assistance Publique Hôpitaux de Paris, Paris 75012, France
| | - Manon Lejeune
- Department of Hematology, Pitié-Salpêtrière Hospital, Assistance Publique Hôpitaux de Paris, Paris 75013, France
| | - Benjamin Crichi
- Department of Internal Medicine, Saint-Louis Hospital, Assistance Publique Hôpitaux de Paris, Paris 75010, France
| | - Corinne Frere
- Department of Hematology, Pitié-Salpêtrière Hospital, Assistance Publique Hôpitaux de Paris, Paris 75013, France
- Inserm UMRS_1166, Institute of Cardiometabolism and Nutrition, Sorbonne Université, Paris 75013, France
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Wu Y, Tu C, Shao C. Inflammatory indexes in preoperative blood routine to predict early recurrence of hepatocellular carcinoma after curative hepatectomy. BMC Surg 2021; 21:178. [PMID: 33794850 PMCID: PMC8017621 DOI: 10.1186/s12893-021-01180-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 03/28/2021] [Indexed: 02/08/2023] Open
Abstract
Background The inflammation indexes in blood routine play an essential role in evaluating the prognosis of patients with hepatocellular carcinoma, but the effect on early recurrence has not been clarified. The study aimed to investigate the risk factors of early recurrence (within 2 years) and recurrence-free survival after curative hepatectomy and explore the role of inflammatory indexes in predicting early recurrence. Methods The baseline data of 161 patients with hepatocellular carcinoma were analyzed retrospectively. The optimal cut-off value of the inflammatory index was determined according to the Youden index. Its predictive performance was compared by the area under the receiver operating characteristic curve. Logistic and Cox regression analyses were used to determine the risk factors of early recurrence and recurrence-free survival. Results The area under the curve of monocyte to lymphocyte ratio (MLR) for predicting early recurrence was 0.700, which was better than systemic inflammatory response index (SIRI), neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) and systemic immune-inflammatory index (SII). MLR, tumour size, tumour differentiation and BCLC stage are all risk factors for early recurrence and recurrence-free survival of HCC. Combining the above four risk factors to construct a joint index, the area under the curve for predicting early recurrence was 0.829, which was better than single MLR, tumour size, tumour differentiation and BCLC stage. Furthermore, with the increase of risk factors, the recurrence-free survival of patients is worse. Conclusion The combination of MLR and clinical risk factors is helpful for clinicians to identify high-risk patients with early recurrence and carry out active postoperative adjuvant therapy to improve the prognosis of patients.
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Affiliation(s)
- YiFeng Wu
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Wenzhou Medical University, Nanbaixiang, Ouhai District, Wenzhou, Zhejiang, People's Republic of China
| | - ChaoYong Tu
- Department of Hepatobiliary and Pancreatic Surgery, The Fifth Affiliated Hospital of Wenzhou Medical University, Lishui Municipal Central Hospital, 289 Kuocang Road, Liandu District, Lishui, Zhejiang, People's Republic of China
| | - ChuXiao Shao
- Department of Hepatobiliary and Pancreatic Surgery, The Fifth Affiliated Hospital of Wenzhou Medical University, Lishui Municipal Central Hospital, 289 Kuocang Road, Liandu District, Lishui, Zhejiang, People's Republic of China.
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6
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Petersen ME, Zhang F, Schupf N, Krinsky‐McHale SJ, Hall J, Mapstone M, Cheema A, Silverman W, Lott I, Rafii MS, Handen B, Klunk W, Head E, Christian B, Foroud T, Lai F, Rosas HD, Zaman S, Ances BM, Wang M, Tycko B, Lee JH, O'Bryant S. Proteomic profiles for Alzheimer's disease and mild cognitive impairment among adults with Down syndrome spanning serum and plasma: An Alzheimer's Biomarker Consortium-Down Syndrome (ABC-DS) study. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2020; 12:e12039. [PMID: 32626817 PMCID: PMC7327223 DOI: 10.1002/dad2.12039] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/02/2020] [Accepted: 04/06/2020] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Previously generated serum and plasma proteomic profiles were examined among adults with Down syndrome (DS) to determine whether these profiles could discriminate those with mild cognitive impairment (MCI-DS) and Alzheimer's disease (DS-AD) from those cognitively stable (CS). METHODS Data were analyzed on n = 305 (n = 225 CS; n = 44 MCI-DS; n = 36 DS-AD) enrolled in the Alzheimer's Biomarker Consortium-Down Syndrome (ABC-DS). RESULTS Distinguishing MCI-DS from CS, the serum profile produced an area under the curve (AUC) = 0.95 (sensitivity [SN] = 0.91; specificity [SP] = 0.99) and an AUC = 0.98 (SN = 0.96; SP = 0.97) for plasma when using an optimized cut-off score. Distinguishing DS-AD from CS, the serum profile produced an AUC = 0.93 (SN = 0.81; SP = 0.99) and an AUC = 0.95 (SN = 0.86; SP = 1.0) for plasma when using an optimized cut-off score. AUC remained unchanged to slightly improved when age and sex were included. Eotaxin3, interleukin (IL)-10, C-reactive protein, IL-18, serum amyloid A , and FABP3 correlated fractions at r2 > = 0.90. DISCUSSION Proteomic profiles showed excellent detection accuracy for MCI-DS and DS-AD.
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Affiliation(s)
- Melissa E. Petersen
- Department of Family Medicine Institute for Translational ResearchUniversity of North Texas Health Science CenterFort WorthTexasUSA
| | - Fan Zhang
- Vermont Genetics NetworkUniversity of VermontBurlingtonVermontUSA
| | - Nicole Schupf
- Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia University Irving Medical CenterNew YorkNew YorkUSA
- G.H. Sergievsky CenterColumbia University Irving Medical CenterNew YorkNew YorkUSA
- Department of Epidemiology, Mailman School of Public HealthColumbia UniversityNew YorkNew YorkUSA
- Department of NeurologyNeurological InstituteColumbia University Irving Medical CenterNew YorkNew YorkUSA
- Department of PsychiatryColumbia University Medical CenterNew YorkNew YorkUSA
| | - Sharon J. Krinsky‐McHale
- Department of PsychologyNYS Institute for Basic Research in Developmental DisabilitiesStaten IslandNew YorkUSA
| | - James Hall
- Department of Pharmacology and Neuroscience Institute for Translational ResearchUniversity of North Texas Health Science CenterFort WorthTexasUSA
| | - Mark Mapstone
- Department of NeurologyUniversity of CaliforniaIrvineCaliforniaUSA
| | - Amrita Cheema
- Georgetown University Medical CenterWashingtonDistrict of ColumbiaUSA
| | - Wayne Silverman
- Department of Pediatrics, School of MedicineUniversity of CaliforniaIrvineCaliforniaUSA
| | - Ira Lott
- Department of Pediatrics, School of MedicineUniversity of CaliforniaIrvineCaliforniaUSA
| | - Michael S. Rafii
- Department of Neurology, Keck School of MedicineUniversity of Southern CaliforniaSan DiegoCaliforniaUSA
| | - Benjamin Handen
- Department of PsychiatryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - William Klunk
- Department of PsychiatryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Elizabeth Head
- Department of PathologyUniversity of CaliforniaIrvineCaliforniaUSA
| | - Brad Christian
- Department of Medical Physics and PsychiatryUniversity of Wisconsin MadisonMadisonWisconsinUSA
| | - Tatiana Foroud
- Department of Medical & Molecular GeneticsIndiana University School of MedicineIndianapolisIndianaUSA
| | - Florence Lai
- Department of Neurology, Massachusetts General HospitalHarvard Medical SchoolCharlestownMassachusettsUSA
| | - H. Diana Rosas
- Departments of Neurology and Radiology, Massachusetts General HospitalHarvard Medical SchoolCharlestownMassachusettsUSA
| | - Shahid Zaman
- Department of Psychiatry, School of Clinical MedicineUniversity of CambridgeCambridgeUK
- Cambridgeshire and Peterborough NHS Foundation TrustFulbourn HospitalCambridgeUK
| | - Beau M. Ances
- Washingston University School of Medicine in St. LouisSt. LouisMissouriUSA
| | - Mei‐Cheng Wang
- Johns Hopkins Bloomberg School of Public HealthBaltimoreMarylandUSA
| | - Benjamin Tycko
- Department of Pathology and Cell BiologyColumbia University Irving Medical CenterNew YorkNew YorkUSA
| | - Joseph H. Lee
- Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia University Irving Medical CenterNew YorkNew YorkUSA
- G.H. Sergievsky CenterColumbia University Irving Medical CenterNew YorkNew YorkUSA
- Department of Epidemiology, Mailman School of Public HealthColumbia UniversityNew YorkNew YorkUSA
- Department of NeurologyNeurological InstituteColumbia University Irving Medical CenterNew YorkNew YorkUSA
| | - Sid O'Bryant
- Department of Pharmacology and Neuroscience Institute for Translational ResearchUniversity of North Texas Health Science CenterFort WorthTexasUSA
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7
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Soliman Z, El Kassas M, Elsharkawy A, Elbadry M, Hamada Y, ElHusseiny R, M El-Nahaas S, Fouad R, Esmat G, Abdel Alem S. Improvement of platelet in thrombocytopenic HCV patients after treatment with direct-acting antiviral agents and its relation to outcome. Platelets 2020; 32:383-390. [PMID: 32250721 DOI: 10.1080/09537104.2020.1742313] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Little is known about evolution of platelet count after treatment with direct-acting antiviral agents (DAAs). The study aimed to evaluate the changes in platelet count after treatment with DAAs among thrombocytopenic patients with HCV-related advanced fibrosis and cirrhosis. A total of 915 chronic HCV patients with advanced fibrosis and cirrhosis who were treated with different DAAs-based regimens were retrospectively enrolled in final analysis. Included patients were those with thrombocytopenia (TCP). Platelet count was recorded at baseline, end of treatment (EOT) and 24-weeks after EOT (SVR24). Changes in platelet count and its relation to SVR were analyzed. The overall SVR24 rate was 98.8%. The platelet count showed statistically significant improvement from baseline to EOT (107 (84-127) × 103/mm3 vs. 120 (87-153) × 103/mm3(P = <0.0001) but remained unchanged thereafter to SVR24. Among responders, the platelet count significantly increased at SVR24 compared to baseline (P = <0.0001) but in relapsers, there was improvement in platelet count that didn't reach statistical significance (P = 0.9). Logistic regression analysis showed that higher Child-Pugh score and more advanced fibrosis at baseline were significant predictors of decreasing of platelet count and development of severe TCP at SVR24. Among thrombocytopenic patients with HCV-related advanced fibrosis and cirrhosis, the platelet count improved after treatment with DAAs regardless to treatment response.
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Affiliation(s)
- Zeinab Soliman
- Endemic Medicine and Hepatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Mohamed El Kassas
- Endemic Medicine Department, Faculty of Medicine, Helwan University, Cairo, Egypt
| | - Aisha Elsharkawy
- Endemic Medicine and Hepatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Mohamed Elbadry
- Tropical Medicine and Gastroenterology Department, Aswan University, Aswan, Egypt
| | - Yasser Hamada
- Endemic Medicine and Hepatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Ramy ElHusseiny
- Internal Medicine Department, National Hepatology and Tropical Medicine Research Institute, Cairo, Egypt
| | - Saeed M El-Nahaas
- Endemic Medicine and Hepatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Rabab Fouad
- Endemic Medicine and Hepatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Gamal Esmat
- Endemic Medicine and Hepatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt.,Department of research development, Badr University, Cairo, Egypt
| | - Shereen Abdel Alem
- Endemic Medicine and Hepatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
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8
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Fukuda T, Hamaguchi M, Osaka T, Hashimoto Y, Ushigome E, Asano M, Yamazaki M, Fukuda E, Yamaguchi K, Ogawa K, Goshima N, Fukui M. A Pilot Study on the Effect of Anti-Thrombopoietin Antibody on Platelet Count in Patients with Type 2 Diabetes. Molecules 2020; 25:molecules25071667. [PMID: 32260359 PMCID: PMC7181124 DOI: 10.3390/molecules25071667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 03/28/2020] [Accepted: 04/03/2020] [Indexed: 12/20/2022] Open
Abstract
Thrombopoietin (THPO) is a circulatory cytokine that plays an important role in platelet production. The presence of anti-THPO antibody relates to thrombocytopenia and is rarely seen in hematopoietic and autoimmune diseases. To date, there had been no reports that focused on the anti-THPO antibody in patients with type 2 diabetes mellitus (T2DM). To evaluate prevalence of the anti-THPO antibody in patients with T2DM and the relationship between anti-THPO antibody and platelet count, a cross-sectional study was performed on 82 patients with T2DM. The anti-THPO antibody was measured by ELISA using preserved sera and detected in 13 patients. The average platelet count was significantly lower in patients with the anti-THPO antibody than in those without the anti-THPO antibody. Multivariate linear regression analyses showed a significant relationship between the anti-THPO antibody and platelet count, after adjusting for other variables. To our best knowledge, this was the first report on the effect of the anti-THPO antibody on platelet count in patients with T2DM. Further investigation is needed to validate the prevalence and pathological significance of the anti-THPO antibody in patients with T2DM.
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Affiliation(s)
- Takuya Fukuda
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto 602-8566, Japan; (T.F.); (T.O.); (Y.H.); (E.U.); (M.A.); (M.Y.); (M.F.)
| | - Masahide Hamaguchi
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto 602-8566, Japan; (T.F.); (T.O.); (Y.H.); (E.U.); (M.A.); (M.Y.); (M.F.)
- Correspondence: ; Tel.: +81-75-251-5505
| | - Takafumi Osaka
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto 602-8566, Japan; (T.F.); (T.O.); (Y.H.); (E.U.); (M.A.); (M.Y.); (M.F.)
- Department of Endocrinology and Diabetology, Ayabe City Hospital, Ayabe 623-0011, Japan
| | - Yoshitaka Hashimoto
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto 602-8566, Japan; (T.F.); (T.O.); (Y.H.); (E.U.); (M.A.); (M.Y.); (M.F.)
| | - Emi Ushigome
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto 602-8566, Japan; (T.F.); (T.O.); (Y.H.); (E.U.); (M.A.); (M.Y.); (M.F.)
| | - Mai Asano
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto 602-8566, Japan; (T.F.); (T.O.); (Y.H.); (E.U.); (M.A.); (M.Y.); (M.F.)
| | - Masahiro Yamazaki
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto 602-8566, Japan; (T.F.); (T.O.); (Y.H.); (E.U.); (M.A.); (M.Y.); (M.F.)
| | - Eriko Fukuda
- Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064, Japan; (E.F.); (K.Y.); (N.G.)
- ProteoBridge Corporation, Tokyo 135-0064, Japan;
| | - Kei Yamaguchi
- Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064, Japan; (E.F.); (K.Y.); (N.G.)
- ProteoBridge Corporation, Tokyo 135-0064, Japan;
| | - Koji Ogawa
- ProteoBridge Corporation, Tokyo 135-0064, Japan;
| | - Naoki Goshima
- Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064, Japan; (E.F.); (K.Y.); (N.G.)
- ProteoBridge Corporation, Tokyo 135-0064, Japan;
| | - Michiaki Fukui
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto 602-8566, Japan; (T.F.); (T.O.); (Y.H.); (E.U.); (M.A.); (M.Y.); (M.F.)
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Koride S, Nayak S, Banfield C, Peterson MC. Evaluating the Role of Janus Kinase Pathways in Platelet Homeostasis Using a Systems Modeling Approach. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2019; 8:478-488. [PMID: 31044523 PMCID: PMC6656939 DOI: 10.1002/psp4.12419] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 03/02/2019] [Indexed: 02/06/2023]
Abstract
Maintaining platelet homeostasis is important to avoid spontaneous bleeding and organ damage. Thrombopoietin, the primary regulator of platelet production, is affected by and acts in part via Janus kinase (JAK)‐signal transducer and activator of transcription (STAT)–mediated mechanisms. Interleukin‐6 is also partly responsible for inducing thrombopoietin production via the JAK‐STAT pathway. Although current understanding suggests that JAK2 is a primary mediator of platelet regulation, the emerging data show that a JAK1‐specific inhibitor resulted in the modulation of platelet numbers following dosing. To gain a mechanistic understanding, a model describing platelet regulation based on known physiology and JAK‐STAT pathways was built. The model provides a tool to coalesce biological understanding of platelet physiology and an in silico experimental platform to explore drug effects on platelet homeostasis. In this article, we explain the model construction and demonstrate the use of JAK‐inhibitor programs as informing probes of the physiology, gaining insights on dosing paradigms that avoid platelet‐related safety concerns.
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Affiliation(s)
- Sarita Koride
- Early Clinical Development, Clinical Pharmacology, Pfizer Inc., Cambridge, Massachusetts, USA
| | - Satyaprakash Nayak
- Global Product Development, Pharmacometrics, Pfizer Inc., Cambridge, Massachusetts, USA
| | - Christopher Banfield
- Early Clinical Development, Clinical Pharmacology, Pfizer Inc., Cambridge, Massachusetts, USA
| | - Mark C Peterson
- Global Product Development, Pharmacometrics, Pfizer Inc., Cambridge, Massachusetts, USA
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10
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Bhat FA, Advani J, Khan AA, Mohan S, Pal A, Gowda H, Chakrabarti P, Keshava Prasad TS, Chatterjee A. A network map of thrombopoietin signaling. J Cell Commun Signal 2018; 12:737-743. [PMID: 30039510 DOI: 10.1007/s12079-018-0480-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 07/05/2018] [Indexed: 10/28/2022] Open
Abstract
Thrombopoietin (THPO), also known as megakaryocyte growth and development factor (MGDF), is a cytokine involved in the production of platelets. THPO is a glycoprotein produced by liver and kidney. It regulates the production of platelets by stimulating the differentiation and maturation of megakaryocyte progenitors. It acts as a ligand for MPL receptor, a member of the hematopoietic cytokine receptor superfamily and is essential for megakaryocyte maturation. THPO binding induces homodimerization of the receptor which results in activation of JAKSTAT and MAPK signaling cascades that subsequently control cellular proliferation, differentiation and other signaling events. Despite the importance of THPO signaling in various diseases and biological processes, a detailed signaling network of THPO is not available in any publicly available database. Therefore, in this study, we present a resource of signaling events induced by THPO that was manually curated from published literature on THPO. Our manual curation of thrombopoietin pathway resulted in identification of 48 molecular associations, 66 catalytic reactions, 100 gene regulation events, 19 protein translocation events and 43 activation/inhibition reactions that occur upon activation of thrombopoietin receptor by THPO. THPO signaling pathway is made available on NetPath, a freely available human signaling pathway resource developed previously by our group. We believe this resource will provide a platform for scientific community to accelerate further research in this area on potential therapeutic interventions.
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Affiliation(s)
- Firdous A Bhat
- Institute of Bioinformatics, International Technology Park, Bangalore, 560 066, India.,School of Biotechnology, Amrita Vishwa Vidyapeetham, Kollam, 690525, India
| | - Jayshree Advani
- Institute of Bioinformatics, International Technology Park, Bangalore, 560 066, India.,Manipal Academy of Higher Education, Manipal, 576104, India
| | - Aafaque Ahmad Khan
- Institute of Bioinformatics, International Technology Park, Bangalore, 560 066, India.,School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, 751024, India
| | - Sonali Mohan
- Institute of Bioinformatics, International Technology Park, Bangalore, 560 066, India
| | - Arnab Pal
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, 160012, India
| | - Harsha Gowda
- Institute of Bioinformatics, International Technology Park, Bangalore, 560 066, India
| | - Prantar Chakrabarti
- Department of Haematology, Nil Ratan Sircar Medical College and Hospital, Kolkata, 700014, India
| | - T S Keshava Prasad
- Institute of Bioinformatics, International Technology Park, Bangalore, 560 066, India. .,Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), University Road, Mangalore, 575018, India.
| | - Aditi Chatterjee
- Institute of Bioinformatics, International Technology Park, Bangalore, 560 066, India.
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11
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Katsube T, Ishibashi T, Kano T, Wajima T. Population Pharmacokinetic and Pharmacodynamic Modeling of Lusutrombopag, a Newly Developed Oral Thrombopoietin Receptor Agonist, in Healthy Subjects. Clin Pharmacokinet 2017; 55:1423-1433. [PMID: 27209291 DOI: 10.1007/s40262-016-0411-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVES The aim of this study was to develop a population pharmacokinetic (PK)/pharmacodynamic (PD) model for describing plasma lusutrombopag concentrations and platelet response following oral lusutrombopag dosing and for evaluating covariates in the PK/PD profiles. METHODS A population PK/PD model was developed using a total of 2539 plasma lusutrombopag concentration data and 1408 platelet count data from 78 healthy adult subjects following oral single and multiple (14-day once-daily) dosing. Covariates in PK and PK/PD models were explored for subject age, body weight, sex, and ethnicity. RESULTS A three-compartment model with first-order rate and lag time for absorption was selected as a PK model. A three-transit and one-platelet compartment model with a sigmoid E max model for drug effect and feedback of platelet production was selected as the PD model. The PK and PK/PD models well described the plasma lusutrombopag concentrations and the platelet response, respectively. Body weight was a significant covariate in PK. The bioavailability of non-Japanese subjects (White and Black/African American subjects) was 13 % lower than that of Japanese subjects, while the simulated platelet response profiles using the PK/PD model were similar between Japanese and non-Japanese subjects. There were no significant covariates of the tested background data including age, sex, and ethnicity (Japanese or non-Japanese) for the PD sensitivity. CONCLUSION A population PK/PD model was developed for lusutrombopag and shown to provide good prediction for the PK/PD profiles. The model could be used as a basic PK/PD model in the drug development of lusutrombopag.
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Affiliation(s)
- Takayuki Katsube
- Clinical Research Department, Shionogi & Co., Ltd., 1-1-4 Shibata, Kita-ku, Osaka, 530-0012, Japan.
| | - Toru Ishibashi
- Clinical Research Department, Shionogi & Co., Ltd., 1-1-4 Shibata, Kita-ku, Osaka, 530-0012, Japan
| | - Takeshi Kano
- Global Project Management Department, Shionogi & Co., Ltd., Kita-ku, Osaka, Japan
| | - Toshihiro Wajima
- Clinical Research Department, Shionogi & Co., Ltd., 1-1-4 Shibata, Kita-ku, Osaka, 530-0012, Japan
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12
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Kurokawa T, Murata S, Zheng YW, Iwasaki K, Kohno K, Fukunaga K, Ohkohchi N. The Eltrombopag antitumor effect on hepatocellular carcinoma. Int J Oncol 2015; 47:1696-702. [PMID: 26397763 PMCID: PMC4599203 DOI: 10.3892/ijo.2015.3180] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 08/21/2015] [Indexed: 12/13/2022] Open
Abstract
Currently, sorafenib is the only available chemotherapeutic agent for advanced hepatocellular carcinoma (HCC), but it cannot be used in patients with liver cirrhosis (LC) or thrombocytopenia. In these cases, sorafenib is likely effective if given in combination with treatments that increase the number of platelets, such as thrombopoietin (TPO) receptor agonists. Increasing the platelet count via TPO treatment resulted in reduction of LC. Eltrombopag (EP), a TPO receptor agonist, has been reported to have antitumor effects against certain cancers, despite their lack of TPO receptor expression. We hypothesized that EP may possess antitumor activity against HCC in addition to its ability to suppress hepatic fibrosis by increasing the platelet count. In the present study, the antitumor activity of EP was examined by assessing the inhibition of cell proliferation and then ascertaining the ability of iron supplementation to reverse these effects in HepG2, Hep3B and Huh7 cells. In addition, a cell cycle assay was performed using flow cytometry, and signal transduction was evaluated by analyzing cell cycle-related protein expression. The results of EP were compared with those of the most common iron chelator, deferoxamine (DFO). The combined effect of EP and sorafenib was also assessed. The results revealed that EP exerts antitumor activity in HCC that is mediated by the modulation of intracellular iron content. EP suppressed the expression of the cell cycle-related protein cyclin D1 and elicited cell cycle arrest in the G0/G1 phase. The activity of EP was comparable to that of DFO in HCC, and EP did not compete with sorafenib at low concentrations. In conclusion, our findings suggest that EP is a good candidate chemotherapeutic agent for the treatment of HCC in patients with LC and thrombocytopenia.
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Affiliation(s)
- Tomohiro Kurokawa
- Department of Surgery, Division of Gastroenterological and Hepatobiliary Surgery, and Organ Transplantation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Soichiro Murata
- Department of Surgery, Division of Gastroenterological and Hepatobiliary Surgery, and Organ Transplantation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Yun-Wen Zheng
- Department of Surgery, Division of Gastroenterological and Hepatobiliary Surgery, and Organ Transplantation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Kenichi Iwasaki
- Department of Surgery, Division of Gastroenterological and Hepatobiliary Surgery, and Organ Transplantation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Keisuke Kohno
- Department of Surgery, Division of Gastroenterological and Hepatobiliary Surgery, and Organ Transplantation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Kiyoshi Fukunaga
- Department of Surgery, Division of Gastroenterological and Hepatobiliary Surgery, and Organ Transplantation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Nobuhiro Ohkohchi
- Department of Surgery, Division of Gastroenterological and Hepatobiliary Surgery, and Organ Transplantation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
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13
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Baird JH, Minniti CP, Lee JM, Tian X, Wu C, Jackson M, Alam S, Taylor JG, Kato GJ. Oscillatory haematopoiesis in adults with sickle cell disease treated with hydroxycarbamide. Br J Haematol 2015; 168:737-46. [PMID: 25377027 PMCID: PMC4323880 DOI: 10.1111/bjh.13203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/15/2014] [Indexed: 11/28/2022]
Abstract
Hydroxycarbamide therapy has been associated with significant oscillations in peripheral blood counts from myeloid, lymphoid and erythroid lineages in patients with polycythaemia vera and chronic myeloid leukaemia. We retrospectively evaluated serial blood counts over an 8-year period from 44 adult patients with sickle cell disease receiving hydroxycarbamide. Platelet counts, leucocyte counts, haemoglobin values and reticulocyte counts, apportioned by hydroxycarbamide status, were analysed using a Lomb-Scargle periodogram algorithm. Significant periodicities were present in one or more counts in 38 patients receiving hydroxycarbamide for a mean duration of 4·81 years. Platelet and leucocyte counts oscillated in 56·8% and 52·3% of patients, respectively. These oscillations generally became detectable within days of initiating therapy. During hydroxycarbamide therapy, the predominant periods of oscillation were 27 ± 1 d for platelet counts and 15 ± 1 d for leucocyte counts. Despite an absolute decrease in leucocyte and platelet counts during hydroxycarbamide treatment, the amplitudes between nadirs and zeniths remained similar regardless of exposure. Our observations appear consistent with previously proposed models of cyclic haematopoiesis, and document that hydroxycarbamide-induced oscillations in blood counts are innocuous phenomena not limited to myeloproliferative disorders as described previously. We speculate the known cell cycle inhibitory properties of hydroxycarbamide may accentuate otherwise latent constitutive oscillatory haematopoiesis.
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Affiliation(s)
- John H. Baird
- Hematology Branch, National Institutes of Health, Bethesda, Maryland, USA
| | | | - Jung-Min Lee
- Medical Oncology Branch, National Cancer Institute; National Institutes of Health, Bethesda, Maryland, USA
| | - Xin Tian
- Office of Biostatistics Research, National Institutes of Health, Bethesda, Maryland, USA
| | - Colin Wu
- Office of Biostatistics Research, National Institutes of Health, Bethesda, Maryland, USA
| | - Mary Jackson
- Hematology Branch, National Institutes of Health, Bethesda, Maryland, USA
| | - Shoaib Alam
- Cardiovascular and Pulmonary Branch, National Heart Lung and Blood Institute; National Institutes of Health, Bethesda, Maryland, USA
| | - James G. Taylor
- Hematology Branch, National Institutes of Health, Bethesda, Maryland, USA
| | - Gregory J. Kato
- Division of Hematology-Oncology, Department of Medicine and the Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
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14
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Murata S, Maruyama T, Nowatari T, Takahashi K, Ohkohchi N. Signal transduction of platelet-induced liver regeneration and decrease of liver fibrosis. Int J Mol Sci 2014; 15:5412-25. [PMID: 24686514 PMCID: PMC4013572 DOI: 10.3390/ijms15045412] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Revised: 03/16/2014] [Accepted: 03/20/2014] [Indexed: 12/16/2022] Open
Abstract
Platelets contain three types of granules: alpha granules, dense granules, and lysosomal granules. Each granule contains various growth factors, cytokines, and other physiological substances. Platelets trigger many kinds of biological responses, such as hemostasis, wound healing, and tissue regeneration. This review presents experimental evidence of platelets in accelerating liver regeneration and improving liver fibrosis. The regenerative effect of liver by platelets consists of three mechanisms; i.e., the direct effect on hepatocytes, the cooperative effect with liver sinusoidal endothelial cells, and the collaborative effect with Kupffer cells. Many signal transduction pathways are involved in hepatocyte proliferation. One is activation of Akt and extracellular signal-regulated kinase (ERK)1/2, which are derived from direct stimulation from growth factors in platelets. The other is signal transducer and activator of transcription-3 (STAT3) activation by interleukin (IL)-6 derived from liver sinusoidal endothelial cells and Kupffer cells, which are stimulated by contact with platelets during liver regeneration. Platelets also improve liver fibrosis in rodent models by inactivating hepatic stellate cells to decrease collagen production. The level of intracellular cyclic adenosine monophosphate (cyclic AMP) is increased by adenosine through its receptors on hepatic stellate cells, resulting in inactivation of these cells. Adenosine is produced by the degradation of adenine nucleotides such as adenosine diphosphate (ADP) and adenosine tri-phosphate (ATP), which are stored in abundance within the dense granules of platelets.
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Affiliation(s)
- Soichiro Murata
- Department of Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
| | - Takehito Maruyama
- Department of Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
| | - Takeshi Nowatari
- Department of Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
| | - Kazuhiro Takahashi
- Department of Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
| | - Nobuhiro Ohkohchi
- Department of Surgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
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15
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Inhibition of megakaryocyte development in the bone marrow underlies dengue virus-induced thrombocytopenia in humanized mice. J Virol 2013; 87:11648-58. [PMID: 23966397 DOI: 10.1128/jvi.01156-13] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A characteristic clinical feature of dengue virus infection is thrombocytopenia, though its underlying mechanism is not definitively determined. By adoptive transfer of human CD34(+) fetal liver cells into immunodeficient mice, we have constructed humanized mice with significant levels of human platelets, monocytes/macrophages, and hepatocytes. Infection of these mice with both lab-adapted and clinical strains of dengue virus induces characteristic human hematological changes, including transient leukopenia and thrombocytopenia. We show that the specific depletion of human platelets is not mediated by antibodies in the periphery or reduced production of human thrombopoietin in the liver but reduction of human megakaryocytes and megakaryocyte progenitors in the bone marrow of the infected mice. These findings identify inhibition of platelet production in the bone marrow as a key mechanism underlying dengue-induced thrombocytopenia and suggest the utility of the improved humanized mouse model in studying dengue virus infection and pathogenesis in a human cell context.
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16
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Kang LI, Mars WM, Michalopoulos GK. Signals and cells involved in regulating liver regeneration. Cells 2012; 1:1261-92. [PMID: 24710554 PMCID: PMC3901148 DOI: 10.3390/cells1041261] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 11/27/2012] [Accepted: 12/07/2012] [Indexed: 12/11/2022] Open
Abstract
Liver regeneration is a complex phenomenon aimed at maintaining a constant liver mass in the event of injury resulting in loss of hepatic parenchyma. Partial hepatectomy is followed by a series of events involving multiple signaling pathways controlled by mitogenic growth factors (HGF, EGF) and their receptors (MET and EGFR). In addition multiple cytokines and other signaling molecules contribute to the orchestration of a signal which drives hepatocytes into DNA synthesis. The other cell types of the liver receive and transmit to hepatocytes complex signals so that, in the end of the regenerative process, complete hepatic tissue is assembled and regeneration is terminated at the proper time and at the right liver size. If hepatocytes fail to participate in this process, the biliary compartment is mobilized to generate populations of progenitor cells which transdifferentiate into hepatocytes and restore liver size.
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Affiliation(s)
- Liang-I Kang
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15261, USA.
| | - Wendy M Mars
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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17
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Stockklausner C, Breit S, Neu-Yilik G, Echner N, Hentze MW, Kulozik AE, Gehring NH. The uORF-containing thrombopoietin mRNA escapes nonsense-mediated decay (NMD). Nucleic Acids Res 2006; 34:2355-63. [PMID: 16679454 PMCID: PMC1458284 DOI: 10.1093/nar/gkl277] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Platelet production is induced by the cytokine thrombopoietin (TPO). It is physiologically critical that TPO expression is tightly regulated, because lack of TPO causes life-threatening thrombocytopenia while an excess of TPO results in thrombocytosis. The plasma concentration of TPO is controlled by a negative feedback loop involving receptor-mediated uptake of TPO by platelets. Furthermore, TPO biosynthesis is limited by upstream open reading frames (uORFs) that curtail the translation of the TPO mRNA. uORFs are suggested to activate RNA degradation by nonsense-mediated decay (NMD) in a number of physiological transcripts. Here, we determine whether NMD affects TPO expression. We show that reporter mRNAs bearing the seventh TPO uORF escape NMD. Importantly, endogenously expressed TPO mRNA from HuH7 cells is unaffected by abrogation of NMD by RNAi. Thus, regulation of TPO expression is independent of NMD, implying that mRNAs bearing uORFs cannot generally be considered to represent NMD targets.
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Affiliation(s)
- Clemens Stockklausner
- Department of Pediatric Oncology, Hematology and Immunology, University of Heidelberg, 69120 Heidelberg, Germany
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18
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Ehrenreich H, Hasselblatt M, Knerlich F, von Ahsen N, Jacob S, Sperling S, Woldt H, Vehmeyer K, Nave KA, Sirén AL. A hematopoietic growth factor, thrombopoietin, has a proapoptotic role in the brain. Proc Natl Acad Sci U S A 2005; 102:862-7. [PMID: 15642952 PMCID: PMC545528 DOI: 10.1073/pnas.0406008102] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2004] [Indexed: 01/19/2023] Open
Abstract
Central nervous and hematopoietic systems share developmental features. We report that thrombopoietin (TPO), a stimulator of platelet formation, acts in the brain as a counterpart of erythropoietin (EPO), a hematopoietic growth factor with neuroprotective properties. TPO is most prominent in postnatal brain, whereas EPO is abundant in embryonic brain and decreases postnatally. Upon hypoxia, EPO and its receptor are rapidly reexpressed, whereas neuronal TPO and its receptor are down-regulated. Unexpectedly, TPO is strongly proapoptotic in the brain, causing death of newly generated neurons through the Ras-extracellular signal-regulated kinase 1/2 pathway. This effect is not only inhibited by EPO but also by neurotrophins. We suggest that the proapoptotic function of TPO helps to select for neurons that have acquired target-derived neurotrophic support.
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Affiliation(s)
- Hannelore Ehrenreich
- Max Planck Institute of Experimental Medicine, Georg-August University, 37075 Goettingen, Germany.
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