Search results for "Protein tyrosine phosphatase"
showing 10 items of 58 documents
Functional polymorphisms in SOCS1 and PTPN22 genes correlate with the response to imatinib treatment in newly diagnosed chronic-phase chronic myeloid…
2011
a b s t r a c t The function of the natural modulators of BCR-ABL-induced signaling pathways could influence the results to imatinib treatment. We assessed the association between single nucleotide polymorphisms (SNPs) on genes of the phosphatase family and the suppressors of cytokine signaling and the response to imatinib in 105 patients newly diagnosed with chronic-phase CML. SNPs in SOCS1 (rs243327) and PTPN22 (rs2476601) genes correlated with the risk of primary resistance to imatinib. A high-risk Sokal score, the T allele in PTPN22 SNP, and each copy of the C allele in SOCS1 SNP were adverse prognostic factors for failure-free survival (FFS). Based on such parameters, three risk groups…
Young woman with Branchio-Oto-Renal Syndrome and a novel mutation in the EYA-1 gene
2011
Branchio-oto-renal (BOR) syndrome is an autosomal dominant disease clinically characterized by the coexistence of some or all of the following major disorders: deafness, cervical branchial fistulae, preauricular pits, and renal abnormalities. Most families with BOR syndrome have mutations on the EYA-1 gene on chromosome 8q. We present the case of a 23-year-old Italian woman without a familial history of BOR syndrome. The patient, who had hearing loss and a history of surgeries for correction of bilateral cervical branchial fistulae and bilateral preauricular pits, presented with renal impairment, hypertension and overt proteinuria. DNA sequencing showed a novel heterozygous mutation 1420-14…
γ-Glutamyl cysteine modulates the inflammatory response via protein phosphatases
2015
Acute pancreatitis (AP) is an acute inflammatory process of the pancreatic gland that may lead to severe systemic complications. Cytokines and oxidative stress play a role in the early pathophysiological events of the disease. Previous studies have shown the antioxidant properties of γ-glutamyl cysteine (γ–GC), a metabolic precursor for the synthesis of glutathione. C57BL/6 mice were treated with cerulein (7 injections each with 50 μg/kg bw). To evaluate the effects of γ-GC, a group of mice with AP was treated with γ-GC (75 mg/kg bw) administered in two doses at 4 and 7 hours after the first cerulein injection. Plasma lipase activity was measured and histological studies were performed to c…
Glucocorticoids inhibit MAP kinase via increased expression and decreased degradation of MKP-1
2001
Glucocorticoids inhibit the proinflammatory activities of transcription factors such as AP-1 and NF-kappa B as well as that of diverse cellular signaling molecules. One of these signaling molecules is the extracellular signal-regulated kinase (Erk-1/2) that controls the release of allergic mediators and the induction of proinflammatory cytokine gene expression in mast cells. The mechanism of inhibition of Erk-1/2 activity by glucocorticoids is unknown. Here we report a novel dual action of glucocorticoids for this inhibition. Glucocorticoids increase the expression of the MAP kinase phosphatase-1 (MKP-1) gene at the promoter level, and attenuate proteasomal degradation of MKP-1, which we re…
Critical Structural Defects Explain Filamin A Mutations Causing Mitral Valve Dysplasia
2019
Mitral valve diseases affect approximately 3% of the population and are the most common reasons for valvular surgery because no drug-based treatments exist. Inheritable genetic mutations have now been established as the cause of mitral valve insufficiency, and four different missense mutations in the filamin A gene (FLNA) have been found in patients suffering from non-syndromic mitral valve dysplasia (MVD). The FLNA protein is expressed, in particular, in endocardial endothelia during fetal valve morphogenesis and is key in cardiac development. The FLNA-MVD causing mutations are clustered in the N-terminal region of FLNA. How the mutations in FLNA modify its structure and function, have mos…
Different protein turnover of interleukin-6-type cytokine signalling components.
1999
Interleukin (IL)-6 and IL-6-type cytokines signal through the gp130/Jak/STAT signal transduction pathway. The key components involved are the signal transducing receptor subunit gp130, the Janus kinases Jak1, Jak2 and Tyk2, STAT1 and STAT3 of the family of signal transducers and activators of transcription, the protein tyrosine phosphatase SHP2 and the suppressors of cytokine signalling SOCS1, SOCS2 and SOCS3. Whereas considerable information has been accumulated concerning the time-course of activation for the individual signalling molecules, data on the availability of the proteins involved in IL-6-type cytokine signal transduction are scarce. Nevertheless, availability of these molecules…
Role of PTPRJ genotype in papillary thyroid carcinoma risk
2010
The strong genetic predisposition to papillary thyroid carcinoma (PTC) might be due to a combination of low-penetrance susceptibility variants. Thus, the research into gene variants involved in the increase of susceptibility to PTC is a relevant field of investigation. The gene coding for the receptor-type tyrosine phosphatase PTPRJ has been proposed as a cancer susceptibility gene, and its role as a tumor suppressor gene is well established in thyroid carcinogenesis. In this study, we want to ascertain the role of PTPRJ genotype in the risk for PTC. We performed a case–control study in which we determined the PTPRJ genotype for the non-synonymous Gln276Pro and Asp872Glu polymorphisms by PC…
Molecular mechanism of T-cell protein tyrosine phosphatase (TCPTP) activation by mitoxantrone.
2013
T-cell protein tyrosine phosphatase (TCPTP) is a ubiquitously expressed non-receptor protein tyrosine phosphatase. It is involved in the negative regulation of many cellular signaling pathways. Thus, activation of TCPTP could have important therapeutic applications in diseases such as cancer and inflammation. We have previously shown that the α-cytoplasmic tail of integrin α1β1 directly binds and activates TCPTP. In addition, we have identified in a large-scale high-throughput screen six small molecules that activate TCPTP. These small molecule activators include mitoxantrone and spermidine. In this study, we have investigated the molecular mechanism behind agonist-induced TCPTP activation.…
Induction of rapid and reversible cytokeratin filament network remodeling by inhibition of tyrosine phosphatases
2002
The cytokeratin filament network is intrinsically dynamic, continuously exchanging subunits over its entire surface, while conferring structural stability on epithelial cells. However, it is not known how cytokeratin filaments are remodeled in situations where the network is temporarily and spatially restricted. Using the tyrosine phosphatase inhibitor orthovanadate we observed rapid and reversible restructuring in living cells, which may provide the basis for such dynamics. By examining cells stably expressing fluorescent cytokeratin chimeras, we found that cytokeratin filaments were broken down and then formed into granular aggregates within a few minutes of orthovanadate addition. After …
Oxidative stress, a new hallmark in the pathophysiology of Lafora progressive myoclonus epilepsy
2015
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