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1.
Nagoya J Med Sci ; 86(2): 326-332, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38962422

RESUMO

We previously reported the Marimo cell line, which was established from the bone marrow cells of a patient with essential thrombocythemia (ET) at the last stage after transformation to acute myeloid leukemia (AML). This cell line is widely used for the biological analysis of ET because it harbors CALR mutation. However, genetic processes during disease progression in the original patient were not analyzed. We sequentially analyzed the genetic status in the original patient samples during disease progression. The ET clone had already acquired CALR and MPL mutations, and TP53 and NRAS mutations affected the disease progression from ET to AML in this patient. Particularly, the variant allele frequency of the NRAS mutation increased along with the disease progression after transformation, and the NRAS-mutated clone selectively proliferated in vitro, resulting in the establishment of the Marimo cell line. Although CALR and MPL mutations co-existed, MPL was not expressed in Marimo cells or any clinical samples. Furthermore, mitogen-activated protein kinase (MAPK) but not the JAK2-STAT pathway was activated. These results collectively indicate that MAPK activation is mainly associated with the proliferation ability of Marimo cells.


Assuntos
Calreticulina , Evolução Clonal , Leucemia Mieloide Aguda , Mutação , Receptores de Trombopoetina , Trombocitemia Essencial , Humanos , Trombocitemia Essencial/genética , Trombocitemia Essencial/patologia , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Calreticulina/genética , Calreticulina/metabolismo , Receptores de Trombopoetina/genética , Evolução Clonal/genética , Janus Quinase 2/genética , Janus Quinase 2/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , GTP Fosfo-Hidrolases/genética , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Masculino , Progressão da Doença , Feminino , Linhagem Celular Tumoral , Idoso , Pessoa de Meia-Idade
2.
Ann Hematol ; 103(7): 2273-2281, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38842566

RESUMO

While studies have explored the feasibility of switching between various thrombopoietin receptor agonists in treating immune thrombocytopenia (ITP), data on the switching from eltrombopag to hetrombopag remains scarce. This post-hoc analysis of a phase III hetrombopag trial aimed to assess the outcomes of ITP patients who switched from eltrombopag to hetrombopag. In the original phase III trial, patients initially randomized to the placebo group were switched to eltrombopag. Those who completed this 14-week eltrombopag were eligible to switch to a 24-week hetrombopag. Treatment response, defined as a platelet count of ≥ 50 × 109/L, and safety were evaluated before and after the switch. Sixty-three patients who completed the 14-week eltrombopag and switched to hetrombopag were included in this post-hoc analysis. Response rates before and after the switch were 66.7% and 88.9%, respectively. Among those with pre-switching platelet counts below 30 × 109/L, eight out of 12 patients (66.7%) responded, while eight out of nine patients (88.9%) with pre-switching platelet counts between 30 × 109/L and 50 × 109/L responded post-switching. Treatment-related adverse events were observed in 50.8% of patients during eltrombopag treatment and 38.1% during hetrombopag treatment. No severe adverse events were noted during hetrombopag treatment. Switching from eltrombopag to hetrombopag in ITP management appears to be effective and well-tolerated. Notably, hetrombopag yielded high response rates, even among patients who had previously shown limited response to eltrombopag. However, these observations need to be confirmed in future trials.


Assuntos
Benzoatos , Hidrazinas , Púrpura Trombocitopênica Idiopática , Pirazóis , Pirazolonas , Receptores de Trombopoetina , Humanos , Pirazóis/uso terapêutico , Pirazóis/efeitos adversos , Pirazóis/administração & dosagem , Masculino , Feminino , Benzoatos/uso terapêutico , Benzoatos/efeitos adversos , Benzoatos/administração & dosagem , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Púrpura Trombocitopênica Idiopática/sangue , Pessoa de Meia-Idade , Adulto , Idoso , Hidrazinas/uso terapêutico , Hidrazinas/efeitos adversos , Hidrazinas/administração & dosagem , Receptores de Trombopoetina/agonistas , Pirazolonas/uso terapêutico , Substituição de Medicamentos , Contagem de Plaquetas , Resultado do Tratamento , Hidrazonas
3.
Platelets ; 35(1): 2359028, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38832545

RESUMO

The purpose of this study is to investigate the molecular interactions and potential therapeutic uses of Eltrombopag (EPAG), a small molecule that activates the cMPL receptor. EPAG has been found to be effective in increasing platelet levels and alleviating thrombocytopenia. We utilized computational techniques to predict and confirm the complex formed by the ligand (EPAG) and the Thrombopoietin receptor (TPO-R) cMPL, elucidating the role of RAS, JAK-2, STAT-3, and other essential elements for downstream signaling. Molecular dynamics (MD) simulations were employed to evaluate the stability of the ligand across specific proteins, showing favorable characteristics. For the first time, we examined the presence of TPO-R in human umbilical cord mesenchymal stem cells (hUCMSC) and human gingival mesenchymal stem cells (hGMSC) proliferation. Furthermore, treatment with EPAG demonstrated angiogenesis and vasculature formation of endothelial lineage derived from both MSCs. It also indicated the activation of critical factors such as RUNX-1, GFI-1b, VEGF-A, MYB, GOF-1, and FLI-1. Additional experiments confirmed that EPAG could be an ideal molecule for protecting against UVB radiation damage, as gene expression (JAK-2, ERK-2, MCL-1, NFkB, and STAT-3) and protein CD90/cMPL analysis showed TPO-R activation in both hUCMSC and hGMSC. Overall, EPAG exhibits significant potential in treating radiation damage and mitigating the side effects of radiotherapy, warranting further clinical exploration.


What is the context?● Chemotherapy, radiation treatment, or immunological disorders can cause a decrease in platelet count (thrombocytopenia) or decrease all blood cell types (pancytopenia) in the bone marrow. This can make it challenging to choose the appropriate cancer treatment plan.● Eltrombopag (EPAG) is an oral non-peptide thrombopoietin (TPO) mimetic that activates the cMPL receptor in the body. This activation leads to cell differentiation and proliferation, stimulating platelet production and reducing thrombocytopenia. The cMPL receptor is present in liver cells, megakaryocytes, and hematopoietic cells. However, its effects on stem cell proliferation and differentiation are not entirely understood.What is the new?● This study delves into the molecular interactions and therapeutic applications of EPAG, a small molecule that activates cMPL (TPO-R).● The study offers a comprehensive analysis of the ligand-receptor complex formation, including an examination of downstream signaling elements. Furthermore, molecular dynamics simulations demonstrate the stability of the ligand when interacting with targeted proteins.● The research investigates the presence of TPO-R on stem cell-derived endothelial cells, shedding insight into the ability of EPAG TPO-mimetic to promote angiogenesis and vasculature formation.● The study revealed that EPAG has the potential to protect against UVB-induced radiation damage and stimulate stem cell growth.What is the implications?The study emphasizes the potential of EPAG as a promising option for addressing radiation injury and minimizing the adverse effects of radiotherapy. It could revolutionize treatments not only for thrombocytopenia but also for enhancing the growth of stem cells. Furthermore, the research deepens our understanding of EPAG's molecular mechanisms, providing valuable insights for developing future drugs and therapeutic approaches for cell therapy to treat radiation damage.


Assuntos
Benzoatos , Pirazóis , Receptores de Trombopoetina , Humanos , Pirazóis/farmacologia , Benzoatos/farmacologia , Receptores de Trombopoetina/metabolismo , Hidrazonas/farmacologia , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/efeitos dos fármacos , Hidrazinas/farmacologia , Hidrazinas/uso terapêutico , Simulação de Dinâmica Molecular , Angiogênese
4.
Medicine (Baltimore) ; 103(24): e38556, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38875377

RESUMO

This study aimed to assess hematological diseases next-generation sequencing (NGS) panel enhances the diagnosis and classification of myeloid neoplasms (MN) using the 5th edition of the WHO Classification of Hematolymphoid Tumors (WHO-HAEM5) and the International Consensus Classification (ICC) of Myeloid Tumors. A cohort of 112 patients diagnosed with MN according to the revised fourth edition of the WHO classification (WHO-HAEM4R) underwent testing with a 141-gene NGS panel for hematological diseases. Ancillary studies were also conducted, including bone marrow cytomorphology and routine cytogenetics. The cases were then reclassified according to WHO-HAEM5 and ICC to assess the practical impact of these 2 classifications. The mutation detection rates were 93% for acute myeloid leukemia (AML), 89% for myelodysplastic syndrome (MDS), 94% for myeloproliferative neoplasm (MPN), and 100% for myelodysplasia/myeloproliferative neoplasm (MDS/MPN) (WHO-HAEM4R). NGS provided subclassified information for 26 and 29 patients with WHO-HAEM5 and ICC, respectively. In MPN, NGS confirmed diagnoses in 16 cases by detecting JAK2, MPL, or CALR mutations, whereas 13 "triple-negative" MPN cases revealed at least 1 mutation. NGS panel testing for hematological diseases improves the diagnosis and classification of MN. When diagnosed with ICC, NGS produces more classification subtype information than WHO-HAEM5.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Mutação , Síndromes Mielodisplásicas , Transtornos Mieloproliferativos , Humanos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Transtornos Mieloproliferativos/genética , Transtornos Mieloproliferativos/diagnóstico , Transtornos Mieloproliferativos/classificação , Adulto , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/classificação , Idoso de 80 Anos ou mais , Janus Quinase 2/genética , Organização Mundial da Saúde , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/classificação , Leucemia Mieloide Aguda/diagnóstico , Receptores de Trombopoetina/genética , Calreticulina/genética , Adulto Jovem
5.
J Pediatr Hematol Oncol ; 46(5): 252-261, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38787686

RESUMO

Thrombopoietin receptor agonists (TPO-RAs) induce trilineage hematopoiesis under conditions with acquired hematopoietic failure. We evaluated safety, tolerability, and preliminary efficacy of a TPO-RA, romiplostim (Nplate), with or without standard-of-care immunosuppressive therapy (±IST) for children (ages < 21 y) with newly diagnosed and relapsed/refractory severe aplastic anemia (SAA) and myelodysplastic syndrome (MDS). Data were collected from an observational study and a single arm interventional pilot study. The safety outcome was treatment-related adverse events (AEs). Efficacy was evaluated by complete hematopoietic response (CHR) at week 24. Romiplostim was commenced at 5 µg/kg/week, with dose escalation of 2.5 µg/kg/week (maximum, 20 µg/kg/dose) based on platelet response. Romiplostim was continued until CHR was observed. Ten subjects (SAA, 9 [IST, 4; without IST, 5]; MDS, 1) completed the study (median age: 9.2 y). Median romiplostim dose was 10 µg/kg/week (range: 5 to 17.5 µg/kg/week). The cumulative incidence of CHR was 70.4% (95% CI, 20.2%-92.6%). Among 21 AEs (Grade 1 to 3), 3 were attributed to romiplostim. At a median posttherapy follow-up of 10.9 months (range: 0.7 to 77.5), no clonal evolution, bone marrow fibrosis or mortality was reported. This proof-of-concept study provides data about short-term safety, tolerability, and preliminary efficacy of romiplostim (±IST) for treatment of pediatric SAA/MDS.


Assuntos
Anemia Aplástica , Síndromes Mielodisplásicas , Receptores Fc , Proteínas Recombinantes de Fusão , Trombopoetina , Humanos , Proteínas Recombinantes de Fusão/uso terapêutico , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/efeitos adversos , Receptores Fc/uso terapêutico , Receptores Fc/administração & dosagem , Anemia Aplástica/tratamento farmacológico , Trombopoetina/uso terapêutico , Trombopoetina/efeitos adversos , Trombopoetina/administração & dosagem , Síndromes Mielodisplásicas/tratamento farmacológico , Síndromes Mielodisplásicas/patologia , Criança , Feminino , Adolescente , Masculino , Adulto Jovem , Pré-Escolar , Projetos Piloto , Adulto , Receptores de Trombopoetina/agonistas
6.
Blood Adv ; 8(13): 3372-3387, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38640435

RESUMO

ABSTRACT: Somatic mutants of calreticulin (CRT) drive myeloproliferative neoplasms (MPNs) via binding to the thrombopoietin receptor (MPL) and aberrant activation of the JAK/STAT pathway. Compared with healthy donors, platelets from mutant CRT-expressing patients with MPN display low cell surface MPL. Additionally, coexpression of MPL with an MPN-linked CRT mutant (CRTDel52) reduces cell surface MPL, suggesting that CRTDel52 may induce MPL degradation. We show that lysosomal degradation is relevant to the turnover of CRTDel52 and MPL. Furthermore, CRTDel52 increases the lysosomal localization and degradation of MPL. Mammalian target of rapamycin (mTOR) inhibitors reduce cellular CRTDel52 and MPL, secreted CRTDel52 levels, and impair CRTDel52-mediated cell proliferation. mTOR inhibition also reduces colony formation and differentiation of CD34+ cells from patients with MPN but not from healthy donors. Together, these findings indicate that low-surface MPL is a biomarker of mutant CRT-mediated MPN and that induced degradation of CRTDel52 and MPL is an avenue for therapeutic intervention.


Assuntos
Calreticulina , Lisossomos , Mutação , Transtornos Mieloproliferativos , Receptores de Trombopoetina , Humanos , Calreticulina/metabolismo , Calreticulina/genética , Receptores de Trombopoetina/metabolismo , Receptores de Trombopoetina/genética , Transtornos Mieloproliferativos/metabolismo , Transtornos Mieloproliferativos/genética , Lisossomos/metabolismo , Proteólise , Serina-Treonina Quinases TOR/metabolismo , Proliferação de Células
7.
Expert Rev Hematol ; 17(4-5): 181-188, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38687471

RESUMO

BACKGROUND: Porcine antilymphocyte globulin (p-ALG) combined with cyclosporine (CsA) has been commonly used for severe aplastic anemia (SAA) patients, but few studies on the combination of p-ALG and thrombopoietin receptor agonist (TPO-RA). RESEARCH DESIGN AND METHODS: We retrospectively analyzed the data of 85 people with diagnosed SAA who underwent p-ALG plus CsA, with or without TPO-RA from 2014 to 2023. RESULTS: The overall response rates were 55.3% and 65.9% at 3 and 6 months, and the TPO-RA group were 66.7% and 72.3% at 3 and 6 months, without TPO-RA group were 27.8% and 55.6%. In multivariate analysis, baseline platelet count of > 10 × 109/L was a simple predictor of favorable response at 6 months (p = 0.015). The median follow-up time for all patients was 39 months (range 0.4 ~ 104), the 5-year overall survival (OS) rate was 90.6% [95% CI = 82.1-95.2%], and the failure-free survival (FFS) rate was 68.9% [95% CI = 56.6-78.4%]. Having hematologic responses in 6 months was an independent positive predictor for FFS (p = 0.000). Twelve patients (14.1%) suffered from serum sickness, and 9.5% of patients had mild hepatic impairment. CONCLUSIONS: p-ALG along with CsA is an effective choice for patients with SAA. p-ALG combined with TPO-RA may contribute to the early restoration of hematopoiesis.


Assuntos
Anemia Aplástica , Soro Antilinfocitário , Ciclosporina , Receptores de Trombopoetina , Humanos , Anemia Aplástica/tratamento farmacológico , Anemia Aplástica/mortalidade , Ciclosporina/uso terapêutico , Masculino , Feminino , Estudos Retrospectivos , Pessoa de Meia-Idade , Soro Antilinfocitário/uso terapêutico , Adulto , Receptores de Trombopoetina/agonistas , Resultado do Tratamento , Animais , Adolescente , Idoso , Suínos , Adulto Jovem , Quimioterapia Combinada , Criança , Índice de Gravidade de Doença , Imunossupressores/uso terapêutico
8.
Biomolecules ; 14(4)2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38672505

RESUMO

Thrombopoietin, the primary regulator of blood platelet production, was postulated to exist in 1958, but was only proven to exist when the cDNA for the hormone was cloned in 1994. Since its initial cloning and characterization, the hormone has revealed many surprises. For example, instead of acting as the postulated differentiation factor for platelet precursors, megakaryocytes, it is the most potent stimulator of megakaryocyte progenitor expansion known. Moreover, it also stimulates the survival, and in combination with stem cell factor leads to the expansion of hematopoietic stem cells. All of these growth-promoting activities have resulted in its clinical use in patients with thrombocytopenia and aplastic anemia, although the clinical development of the native molecule illustrated that "it's not wise to mess with mother nature", as a highly engineered version of the native hormone led to autoantibody formation and severe thrombocytopenia. Finally, another unexpected finding was the role of the thrombopoietin receptor in stem cell biology, including the development of myeloproliferative neoplasms, an important disorder of hematopoietic stem cells. Overall, the past 30 years of clinical and basic research has yielded many important insights, which are reviewed in this paper.


Assuntos
Plaquetas , Trombopoetina , Trombopoetina/metabolismo , Humanos , Plaquetas/metabolismo , Animais , Receptores de Trombopoetina/metabolismo , Receptores de Trombopoetina/genética , Trombopoese , Trombocitopenia/metabolismo , Megacariócitos/metabolismo , Megacariócitos/citologia
10.
Br J Haematol ; 204(5): 1605-1616, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38586911

RESUMO

Essential thrombocythaemia (ET) is a myeloproliferative neoplasm characterized by an increased risk of vascular complications and a tendency to progress to myelofibrosis and acute leukaemia. ET patients have traditionally been stratified into two thrombosis risk categories based on age older than 60 years and a history of thrombosis. More recently, the revised IPSET-thrombosis scoring system, which accounts for the increased risk linked to the JAK2 mutation, has been incorporated into most expert recommendations. However, there is increasing evidence that the term ET encompasses different genomic entities, each with a distinct clinical course and prognosis. Moreover, the effectiveness and toxicity of cytoreductive and anti-platelet treatments differ depending on the molecular genotype. While anti-platelets and conventional cytoreductive agents, mainly hydroxycarbamide (hydroxyurea), anagrelide and pegylated interferon, remain the cornerstone of treatment, recent research has shed light on the effectiveness of novel therapies that may help improve outcomes. This comprehensive review focuses on the evolving landscape of treatment strategies in ET, with an emphasis on the role of molecular profiling in guiding therapeutic decisions. Besides evidence-based management according to revised IPSET-thrombosis stratification, we also provide specific observations for those patients with CALR-, MPL-mutated and triple-negative ET, as well as cases with high-risk mutations.


Assuntos
Trombocitemia Essencial , Humanos , Trombocitemia Essencial/tratamento farmacológico , Trombocitemia Essencial/genética , Janus Quinase 2/genética , Janus Quinase 2/antagonistas & inibidores , Inibidores da Agregação Plaquetária/uso terapêutico , Inibidores da Agregação Plaquetária/efeitos adversos , Mutação , Receptores de Trombopoetina/agonistas , Receptores de Trombopoetina/genética , Calreticulina
11.
Cancer Med ; 13(7): e7123, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38618943

RESUMO

OBJECTIVE: To evaluate the incidence, clinical laboratory characteristics, and gene mutation spectrum of Ph-negative MPN patients with atypical variants of JAK2, MPL, or CALR. METHODS: We collected a total of 359 Ph-negative MPN patients with classical mutations in driver genes JAK2, MPL, or CALR, and divided them into two groups based on whether they had additional atypical variants of driver genes JAK2, MPL, or CALR: 304 patients without atypical variants of driver genes and 55 patients with atypical variants of driver genes. We analyzed the relevant characteristics of these patients. RESULTS: This study included 359 patients with Ph-negative MPNs with JAK2, MPL, or CALR classical mutations and found that 55 (15%) patients had atypical variants of JAK2, MPL, or CALR. Among them, 28 cases (51%) were male, and 27 (49%) were female, with a median age of 64 years (range, 21-83). The age of ET patients with atypical variants was higher than that of ET patients without atypical variants [70 (28-80) vs. 61 (19-82), p = 0.03]. The incidence of classical MPL mutations in ET patients with atypical variants was higher than in ET patients without atypical variants [13.3% (2/15) vs. 0% (0/95), p = 0.02]. The number of gene mutations in patients with atypical variants of driver genes PV, ET, and Overt-PMF is more than in patients without atypical variants of PV, ET, and Overt-PMF [PV: 3 (2-6) vs. 2 (1-7), p < 0.001; ET: 4 (2-8) vs. 2 (1-7), p < 0.05; Overt-PMF: 5 (2-9) vs. 3 (1-8), p < 0.001]. The incidence of SH2B3 and ASXL1 mutations were higher in MPN patients with atypical variants than in those without atypical variants (SH2B3: 16% vs. 6%, p < 0.01; ASXL1: 24% vs. 13%, p < 0.05). CONCLUSION: These data indicate that classical mutations of JAK2, MPL, and CALR may not be completely mutually exclusive with atypical variants of JAK2, MPL, and CALR. In this study, 30 different atypical variants of JAK2, MPL, and CALR were identified, JAK2 G127D being the most common (42%, 23/55). Interestingly, JAK2 G127D only co-occurred with JAK2V617F mutation. The incidence of atypical variants of JAK2 in Ph-negative MPNs was much higher than that of the atypical variants of MPL and CALR. The significance of these atypical variants will be further studied in the future.


Assuntos
Laboratórios Clínicos , Fatores de Transcrição , Humanos , Feminino , Masculino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Mutação , Receptores de Trombopoetina/genética , Janus Quinase 2/genética
12.
Br J Haematol ; 204(5): 2077-2085, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38462764

RESUMO

Diamond-Blackfan anaemia (DBA) is a rare, inherited bone marrow failure syndrome with a ribosomal defect causing slowed globin chain production with normal haem synthesis, causing an overabundance of reactive iron/haem and erythroid-specific cellular toxicity. Eltrombopag, a non-peptide thrombopoietin receptor agonist, is a potent intracellular iron chelator and induced a robust durable response in an RPS19-mutated DBA patient on another trial. We hypothesized eltrombopag would improve RBC production in DBA patients. We conducted a single-centre, single-arm pilot study (NCT04269889) assessing safety and erythroid response of 6 months of daily, fixed-dose eltrombopag for DBA patients. Fifteen transfusion-dependent (every 3-5 weeks) patients (median age 18 [range 2-56]) were treated. One responder had sustained haemoglobin improvement and >50% reduction in RBC transfusion frequency. Of note, 7/15 (41%) patients required dose reductions or sustained discontinuation of eltrombopag due to asymptomatic thrombocytosis. Despite the low response rate, eltrombopag has now improved erythropoiesis in several patients with DBA with a favourable safety profile. Dosing restrictions due to thrombocytosis may cause insufficient iron chelation to decrease haem production and improve anaemia in most patients. Future work will focus on erythropoiesis dynamics in patients and use of haem synthesis inhibitors without an impact on other haematopoietic lineages.


Assuntos
Anemia de Diamond-Blackfan , Benzoatos , Hidrazinas , Pirazóis , Humanos , Anemia de Diamond-Blackfan/tratamento farmacológico , Pirazóis/uso terapêutico , Hidrazinas/uso terapêutico , Hidrazinas/administração & dosagem , Hidrazinas/efeitos adversos , Benzoatos/uso terapêutico , Benzoatos/administração & dosagem , Benzoatos/efeitos adversos , Adulto , Masculino , Feminino , Criança , Adolescente , Pessoa de Meia-Idade , Adulto Jovem , Pré-Escolar , Projetos Piloto , Resultado do Tratamento , Receptores de Trombopoetina/agonistas , Recidiva , Eritropoese/efeitos dos fármacos
13.
Leukemia ; 38(6): 1342-1352, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38491305

RESUMO

Thrombopoietin (Tpo), which binds to its specific receptor, the Mpl protein, is the major cytokine regulator of megakaryopoiesis and circulating platelet number. Tpo binding to Mpl triggers activation of Janus kinase 2 (Jak2) and phosphorylation of the receptor, as well as activation of several intracellular signalling cascades that mediate cellular responses. Three tyrosine (Y) residues in the C-terminal region of the Mpl intracellular domain have been implicated as sites of phosphorylation required for regulation of major Tpo-stimulated signalling pathways: Mpl-Y565, Mpl-Y599 and Mpl-Y604. Here, we have introduced mutations in the mouse germline and report a consistent physiological requirement for Mpl-Y599, mutation of which resulted in thrombocytopenia, deficient megakaryopoiesis, low hematopoietic stem cell (HSC) number and function, and attenuated responses to myelosuppression. We further show that in models of myeloproliferative neoplasms (MPN), where Mpl is required for pathogenesis, thrombocytosis was dependent on intact Mpl-Y599. In contrast, Mpl-Y565 was required for negative regulation of Tpo responses; mutation of this residue resulted in excess megakaryopoiesis at steady-state and in response to myelosuppression, and exacerbated thrombocytosis associated with MPN.


Assuntos
Hematopoese , Transtornos Mieloproliferativos , Receptores de Trombopoetina , Trombopoetina , Tirosina , Animais , Receptores de Trombopoetina/metabolismo , Receptores de Trombopoetina/genética , Transtornos Mieloproliferativos/genética , Transtornos Mieloproliferativos/metabolismo , Transtornos Mieloproliferativos/patologia , Camundongos , Trombopoetina/metabolismo , Tirosina/metabolismo , Tirosina/genética , Fosforilação , Camundongos Endogâmicos C57BL , Células-Tronco Hematopoéticas/metabolismo , Transdução de Sinais , Mutação , Janus Quinase 2/genética , Janus Quinase 2/metabolismo , Trombopoese/genética
14.
Br J Haematol ; 204(6): 2442-2452, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38429869

RESUMO

Few studies have reported the real-world use of both romiplostim and eltrombopag in immune thrombocytopenia (ITP). TRAIT was a retrospective observational study aimed to evaluate the platelet responses and adverse effects associated with the use of these thrombopoietin receptor agonists (TPO-RAs) in adult patients with ITP in the United Kingdom. Of 267 patients (median age at diagnosis, 48 years) with ITP (primary ITP [n = 218], secondary ITP [n = 49]) included in the study, 112 (42%) received eltrombopag and 155 (58%) received romiplostim as the first prescribed TPO-RA. A platelet count ≥30 × 109/L was achieved in 89% of patients with the first TPO-RA treatments, while 68% achieved a platelet count ≥100 × 109/L. Treatment-free response (TFR; platelet count ≥30 × 109/L, 3 months after discontinuing treatment) was achieved by 18% of the total patients. Overall, 61 patients (23%) switched TPO-RAs, most of whom achieved platelet counts ≥30 × 109/L with the second TPO-RA (23/25 who switched from eltrombopag to romiplostim [92%]; 28/36 who switched from romiplostim to eltrombopag [78%]). TFR was associated with secondary ITP, early TPO-RA initiation after diagnosis, the presence of comorbidity and no prior splenectomy or treatment with steroids or mycophenolate mofetil. Both TPO-RAs had similar efficacy and safety profiles to those reported in clinical studies.


Assuntos
Benzoatos , Hidrazinas , Púrpura Trombocitopênica Idiopática , Pirazóis , Receptores Fc , Receptores de Trombopoetina , Proteínas Recombinantes de Fusão , Trombopoetina , Humanos , Receptores de Trombopoetina/agonistas , Proteínas Recombinantes de Fusão/uso terapêutico , Proteínas Recombinantes de Fusão/efeitos adversos , Proteínas Recombinantes de Fusão/administração & dosagem , Pessoa de Meia-Idade , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Benzoatos/uso terapêutico , Benzoatos/efeitos adversos , Masculino , Feminino , Pirazóis/uso terapêutico , Pirazóis/efeitos adversos , Trombopoetina/uso terapêutico , Trombopoetina/efeitos adversos , Hidrazinas/uso terapêutico , Hidrazinas/efeitos adversos , Receptores Fc/uso terapêutico , Adulto , Reino Unido , Estudos Retrospectivos , Idoso , Contagem de Plaquetas , Resultado do Tratamento , Idoso de 80 Anos ou mais , Adulto Jovem , Adolescente
16.
Arch Toxicol ; 98(6): 1843-1858, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38551724

RESUMO

Acetaminophen (APAP)-induced hepatotoxicity is comprised of an injury and recovery phase. While pharmacological interventions, such as N-acetylcysteine (NAC) and 4-methylpyrazole (4-MP), prevent injury there are no therapeutics that promote recovery. JNJ-26366821 (TPOm) is a novel thrombopoietin mimetic peptide with no sequence homology to endogenous thrombopoietin (TPO). Endogenous thrombopoietin is produced by hepatocytes and the TPO receptor is present on liver sinusoidal endothelial cells in addition to megakaryocytes and platelets, and we hypothesize that TPOm activity at the TPO receptor in the liver provides a beneficial effect following liver injury. Therefore, we evaluated the extent to which TPOm, NAC or 4-MP can provide a protective and regenerative effect in the liver when administered 2 h after an APAP overdose of 300 mg/kg in fasted male C57BL/6J mice. TPOm did not affect protein adducts, oxidant stress, DNA fragmentation and hepatic necrosis up to 12 h after APAP. In contrast, TPOm treatment was beneficial at 24 h, i.e., all injury parameters were reduced by 42-48%. Importantly, TPOm enhanced proliferation by 100% as indicated by PCNA-positive hepatocytes around the area of necrosis. When TPOm treatment was delayed by 6 h, there was no effect on the injury, but a proliferative effect was still evident. In contrast, 4MP and NAC treated at 2 h after APAP significantly attenuated all injury parameters at 24 h but failed to enhance hepatocyte proliferation. Thus, TPOm arrests the progression of liver injury by 24 h after APAP and accelerates the onset of the proliferative response which is essential for liver recovery.


Assuntos
Acetaminofen , Doença Hepática Induzida por Substâncias e Drogas , Regeneração Hepática , Fígado , Camundongos Endogâmicos C57BL , Trombopoetina , Animais , Acetaminofen/toxicidade , Masculino , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Trombopoetina/farmacologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Regeneração Hepática/efeitos dos fármacos , Camundongos , Acetilcisteína/farmacologia , Pirazóis/farmacologia , Hepatócitos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Receptores de Trombopoetina/metabolismo , Proliferação de Células/efeitos dos fármacos
18.
Clin Invest Med ; 47(1): 13-22, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38546381

RESUMO

INTRODUCTION: Immune thrombocytopenia (ITP) is an autoimmune disease characterized by low platelet counts and increased risk of bleeding. After corticosteroids with or without intravenous immune globulin (first-line treatment), second-line treatment options include rituximab, splenectomy, thrombopoietin receptor agonists (TPO-RAs), and fostamatinib. In Canada, the choice of second-line therapy is influenced by access to medications. The goals of this narrative review are to 1) summarize the evidence for the use of TPO-RAs and other second-line therapies in ITP and 2) highlight differences in public funding criteria for TPO-RAs across provinces and territories in Canada. METHODS: We conducted a literature review of second-line therapies for ITP. We solicited information on public funding programs for TPO-RAs in Canada from health care providers, pharmacists, and provincial ministries of health. RESULTS: Head-to-head trials involving TPO-RAs, rituximab, splenectomy, and fostamatinib are lacking. There is substantial evidence of effect for TPO-RAs in improving platelet count levels, health-related quality of life, bleeding, and fatigue from placebo-controlled trials and observational studies; however, access to TPO-RAs through provincial funding programs in Canada is variable. Splenectomy failure is a prerequisite for the funding of TPO-RAs in Ontario, Manitoba, and Saskatchewan, but not in Alberta or Quebec. Other provinces either do not have access to public funding or funding is provided on a case-by-case basis. DISCUSSION: TPO-RAs are effective second-line therapies for the treatment of ITP; however, access is variable across Canada, which results in health disparities and poor uptake of international treatment guidelines.


Assuntos
Aminopiridinas , Morfolinas , Púrpura Trombocitopênica Idiopática , Pirimidinas , Receptores de Trombopoetina , Humanos , Aminopiridinas/uso terapêutico , Morfolinas/uso terapêutico , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Pirimidinas/uso terapêutico , Qualidade de Vida , Receptores de Trombopoetina/agonistas , Rituximab/uso terapêutico
19.
Sensors (Basel) ; 24(4)2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38400263

RESUMO

Stroke represents a medical emergency and can lead to the development of movement disorders such as abnormal muscle tone, limited range of motion, or abnormalities in coordination and balance. In order to help stroke patients recover as soon as possible, rehabilitation training methods employ various movement modes such as ordinary movements and joint reactions to induce active reactions in the limbs and gradually restore normal functions. Rehabilitation effect evaluation can help physicians understand the rehabilitation needs of different patients, determine effective treatment methods and strategies, and improve treatment efficiency. In order to achieve real-time and accuracy of action detection, this article uses Mediapipe's action detection algorithm and proposes a model based on MPL-CNN. Mediapipe can be used to identify key point features of the patient's upper limbs and simultaneously identify key point features of the hand. In order to detect the effect of rehabilitation training for upper limb movement disorders, LSTM and CNN are combined to form a new LSTM-CNN model, which is used to identify the action features of upper limb rehabilitation training extracted by Medipipe. The MPL-CNN model can effectively identify the accuracy of rehabilitation movements during upper limb rehabilitation training for stroke patients. In order to ensure the scientific validity and unified standards of rehabilitation training movements, this article employs the postures in the Fugl-Meyer Upper Limb Rehabilitation Training Functional Assessment Form (FMA) and establishes an FMA upper limb rehabilitation data set for experimental verification. Experimental results show that in each stage of the Fugl-Meyer upper limb rehabilitation training evaluation effect detection, the MPL-CNN-based method's recognition accuracy of upper limb rehabilitation training actions reached 95%. At the same time, the average accuracy rate of various upper limb rehabilitation training actions reaches 97.54%. This shows that the model is highly robust across different action categories and proves that the MPL-CNN model is an effective and feasible solution. This method based on MPL-CNN can provide a high-precision detection method for the evaluation of rehabilitation effects of upper limb movement disorders after stroke, helping clinicians in evaluating the patient's rehabilitation progress and adjusting the rehabilitation plan based on the evaluation results. This will help improve the personalization and precision of rehabilitation treatment and promote patient recovery.


Assuntos
Transtornos dos Movimentos , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Humanos , Extremidade Superior/fisiologia , Mãos , Movimento/fisiologia , Resultado do Tratamento , Recuperação de Função Fisiológica/fisiologia , Receptores de Trombopoetina
20.
Br J Haematol ; 204(4): 1143-1145, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38319005

RESUMO

Immune thrombocytopenia refractory to multiple thrombopoietin receptor agonists remains a challenging clinical problem. This commentary discusses and contextualizes the recent report on this entity from Moulis and colleagues, and how to move forward with these patients. Commentary on: Moulis et al. Difficult-to-treat primary immune thrombocytopenia in adults: Prevalence and burden. Results from the CARMEN-France Registry. Br J Haematol 2024;204:1476-1482.


Assuntos
Púrpura Trombocitopênica Idiopática , Pirazóis , Trombocitopenia , Adulto , Humanos , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Receptores de Trombopoetina/agonistas , Trombocitopenia/tratamento farmacológico , Trombopoetina/uso terapêutico , Benzoatos/uso terapêutico , Hidrazinas/uso terapêutico , Receptores Fc/uso terapêutico , Proteínas Recombinantes de Fusão/uso terapêutico
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