Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.56 (caspase-3)
 35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To investigate whether altered megakaryocyte morphology contributes to reduced platelet production in idiopathic thrombocytopenic purpura (ITP), ultrastructural analysis of megakaryocytes was performed in 11 ITP patients. Ultrastructural abnormalities compatible with (para-)apoptosis were present in 78% +/- 14% of ITP megakaryocytes, which could be reversed by in vivo treatment with prednisone and intravenous immunoglobulin. Immunohistochemistry of bone marrow biopsies of ITP patients with extensive apoptosis showed an increased number of megakaryocytes with activated caspase-3 compared with normal (28% +/- 4% versus 0%). No difference, however, was observed in the number of bone marrow megakaryocyte colony-forming units (ITP, 118 +/- 93/105 bone marrow cells; versus controls, 128 +/- 101/105 bone marrow cells; P =.7). To demonstrate that circulating antibodies might affect megakaryocytes, suspension cultures of CD34+ cells were performed with ITP or normal plasma. Morphology compatible with (para-)apoptosis could be induced in cultured megakaryocytes with ITP plasma (2 of 10 samples positive for antiplatelet autoantibodies). Finally, the plasma glycocalicin index, a parameter of platelet and megakaryocyte destruction, was increased in ITP (57 +/- 70 versus 0.7 +/- 0.2; P =.009) and correlated with the proportion of megakaryocytes showing (para-) apoptotic ultrastructure (P =.02; r = 0.7). In conclusion, most ITP megakaryocytes show ultrastructural features of (para-) apoptosis, probably due to action of factors present in ITP plasma.
 ...
PMID:Ultrastructural study shows morphologic features of apoptosis and para-apoptosis in megakaryocytes from patients with idiopathic thrombocytopenic purpura. 1296 75

Immune thrombocytopenia is a heterogeneous autoimmune disease, characterized by accelerated platelet destruction and impaired platelet production. Bcl-xL and Bax play an opposite role in the regulation of apoptotic process with Bcl-xL for cell survival and Bax for cell apoptosis. Given the critical roles in the regulation of platelet apoptosis, whether Bcl-xL or Bax was involved in the pathogenesis of ITP remains unknown. The aim of this study is to evaluate the expression profile of Bcl-xL and Bax in platelets treated with ITP plasma. Normal washed platelets were treated with plasma from 20 active ITP patients or 10 age and gender-matched control to mimic the ITP in vivo environment. Mitochondrial depolarization, platelet apoptosis and activation were measured by flow cytometry. Expression of Bcl-xL, Bax and caspase-3 were also measured by quantitative real-time PCR and western blot. Our results demonstrated increased mitochondrial depolarization, platelet apoptosis and activation in platelets after treated with ITP plasma in comparison to control. In addition, decreased expression of Bcl-xL, increased expression of Bax and activity of caspase-3 were also observed. Furthermore, a negative correlation of Bcl-xL with Bax was found in platelets treated with ITP plasma. In conclusion, imbalanced expression of Bcl-xL and Bax might be associated with platelet apoptosis in ITP and therapeutically targeting them might be a novel approach in the treatment of ITP.
...
PMID:Imbalanced expression of Bcl-xL and Bax in platelets treated with plasma from immune thrombocytopenia. 2671 45