Background: Glucocorticoids are widely known for their immunomodulatory action. Their synthetic analogs are used to treat several autoimmune diseases, including immune thrombocytopenia. However, their efficacy and mechanisms of action in immune thrombocytopenia are not fully understood.
Objectives: To investigate the mechanism of glucocorticoid actions on platelet production.
Methods: The actions of glucocorticoids on platelet production were studied combining in vivo, ex vivo and in vitro approaches.
Results: Dexamethasone reduced bleeding in mice and rapidly increased circulating young platelet counts. In vitro glucocorticoid treatment stimulated proplatelet formation by megakaryocytes and platelet-like particle release. This effect was blocked by glucocorticoid receptor antagonist RU486, indicating a glucocorticoid receptor-dependent mechanism. Genome-wide analysis revealed that dexamethasone regulates the expression of >1000 genes related to numerous cellular functions, including predominant cytoplasm and cytoskeleton reorganization. Dexamethasone and other glucocorticoids induced the expression of Gda (the gene encoding guanine deaminase), which has been reported to have a role in dendrite development. Inhibition of guanine deaminase enzymatic activity blocked dexamethasone stimulation of proplatelet formation, implicating a critical role for this enzyme in glucocorticoid-mediated platelet production.
Conclusion: Our findings identify glucocorticoids as new regulators of thrombopoiesis.
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http://dx.doi.org/10.1016/j.jtha.2023.06.012 | DOI Listing |
Front Med (Lausanne)
January 2025
Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu, China.
An 83-year-old male presented to our Digestive System Department with a 5-day history of severe gastrointestinal (GI) bleeding and a 14-year history of idiopathic thrombocytopenic purpura (ITP) with low platelet levels. Colonoscopy revealed extensive telangiectasias throughout the colon, particularly in the transverse and ascending segments. Standard treatment with proton-pump inhibitors and somatostatin proved ineffective.
View Article and Find Full Text PDFClin Pediatr (Phila)
February 2025
Department of Biochemistry, University Children's Hospital Belgrade, Beograd, Serbia.
Immune thrombocytopenic purpura (ITP) is an acquired immune-mediated bleeding disorder characterized by isolated low platelet (PLT) counts. Immune thrombocytopenic purpura pathogenesis involves multiple immune mechanisms causing PLT destruction and inadequate production. Owing to impaired immune homeostasis, ITP patients can develop other than anti-PLT autoantibodies even in the absence of clinical signs of autoimmune disease, such as anti-thyroglobulin (TG) and anti-thyroperoxidase (TPO) antibodies.
View Article and Find Full Text PDFCase Rep Womens Health
March 2025
Sakai City Medical Center, 1-1-1, Ebaraji-cho, Nishi-ku, Sakai, Osaka 593-8304, Japan.
Intramural pregnancy (IMP) is an extremely rare form of ectopic pregnancy (EP), typically associated with previous uterine trauma, adenomyosis, or assisted reproductive technology (ART), such as embryo transfer (ET). Despite its potentially life-threatening nature, the absence of definitive preoperative diagnostic criteria for IMP complicates its early detection and management, especially in patients without known risk factors. Additionally, management becomes more challenging when there is an elevated risk of hemorrhage.
View Article and Find Full Text PDFBlood Adv
January 2025
Hôpital Henri Mondor, Créteil, France.
To assess efficacy and safety of dapsone in adult immune thrombocytopenia (ITP), a multicenter randomized controlled trial (RCT) and a real-word study cohort were performed. Participants were adults with primary ITP, transient response to corticosteroids ± intravenous immunoglobulin, and a platelet count ≤ 30x109/L (or ≤ 50x109/L with bleeding). Patients in the RCT were randomized in arm A (prednisone x3weeks+dapsone for 12 months) or arm B (prednisone alone).
View Article and Find Full Text PDFInt J Hematol
January 2025
Department of Blood Transfusion, Osaka University Hospital, Osaka, Japan.
Fostamatinib had superior efficacy to a placebo and acceptable safety profiles for at least 1 year in a phase 3 study of Japanese patients with primary immune thrombocytopenia. Here, we report the 3-year safety and efficacy of fostamatinib in that study. Data from 33 patients who received at least one dose of fostamatinib were analyzed.
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