Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The association of Epstein-Barr virus (EBV) with smooth-muscle tumors was recently reported in the setting of acquired immunodeficiency syndrome (AIDS) and post-transplantation. We report a case of an EBV-associated smooth-muscle tumor arising in a post-transplant (PT) patient who previously was treated successfully for two EBV-associated PT large-cell lymphomas. A 4-year-old girl required cardiac transplantation for dilated cardiomyopathy when she was aged 23 months. Her PT regimen included cyclosporine, azothiaprine, and diltiazem. At 16 months PT, she presented with anemia, guaiac-positive stools, and an abdominal mass diagnosed as diffuse large-cell lymphoma of B-cell phenotype. Immunosuppressive therapy was reduced, and interferon and i.v. immunoglobulin were initiated. She rapidly developed signs of rejection, and a cardiac biopsy was performed, revealing grade IIIB rejection. Subsequently, immunosuppressive therapy increased. At 23 months PT, a biopsy was done of a large pelvic mass that was diagnosed as immunoblastic large-cell lymphoma. After treatment with chemotherapy and retinoic acid, the size of the mass markedly decreased. Follow-up computed tomography scan revealed multiple liver nodules. A needle biopsy of the liver showed a smooth-muscle tumor of indeterminate grade. Both the lymphomas and the smooth-muscle tumor contained EBV within > 95% of tumor cells by Epstein-Barr (EBER1) in situ hybridization, were of strain type A by Epstein-Barr nuclear antigen-2 (EBNA-2) polymerase chain reaction (PCR) and contained an identical 30 base-pair deletion (amino acids 346-355) of the latent membrane protein (LMP)-1 oncogene by PCR analysis. Notably, the initial large-cell lymphoma and the subsequent immunoblastic lymphoma each contained a unique p53 mutation, suggesting that they were distinct. These data suggest that the same virus contributed to the pathogenesis of both the malignant lymphomas and the smooth-muscle tumor.
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PMID:Epstein-Barr virus (EBV)-associated smooth-muscle tumor arising in a post-transplant patient treated successfully for two PT-EBV-associated large-cell lymphomas. Case report. 894 45

This investigation focused on whether apoptosis can be observed in some heart diseases. Apoptosis was examined immunochemically using monoclonal antibodies such as p53, Bcl-2 and cyclin E, A, and B1 in parallel with flow cytometry. Left ventricular myocardium was obtained at autopsy from 40 patients with acute myocarditis (AM; N = 10, 6 males, 4 females, mean age 56 +/- 13 years), chronic myocarditis (CM; N = 10, 5 males, 5 females, mean age 48 +/- 16 years), dilated cardiomyopathy (DCM; N = 10, 7 males, 3 females, mean age 60 +/- 11 years), and no heart disease (Cont; N = 10, 5 males, 5 females, mean age 63 +/- 14 years). Cell cycle analysis of myocytes by flow cytometry revealed that the relative content of G2M phase in acute myocarditis was far higher than those in other heart diseases (AM, 12.3 +/- 3.7%; CM, 5.2 +/- 4.5%; DCM, 6.3 +/- 4.0%; Cont, 3.4 +/- 1.8%; Mean +/- SD). Expression of p53 was observed mainly in myocytes from chronic myocarditis. Expression of Bcl-2, on the other hand, was detected in myocytes from acute myocarditis. Results suggest that apoptosis may play some role in the repairing process of myocardial inflammation.
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PMID:Stress signal to survival and apoptosis. 1041 52

Coxsackievirus is the most prevalent virus associated with the pathogenesis of myocarditis and its sequela dilated cardiomyopathy. We have previously shown that coxsackievirus infection facilitates the ubiquitin/proteasome processing of the cell-cycle protein cyclin D1 and the tumor suppressor p53, which raises the possibility that the ubiquitin/proteasome pathway may be used by virus to promote viral replication. In this study, we examined the interplay between coxsackievirus replication and the ubiquitin/proteasome pathway in murine cardiomyocytes. We found that treatment of cells with the proteasome inhibitors MG132 or lactacystin significantly decreased virus titers in the supernatant and prevented virus-induced cell death. We further examined the effects of proteasome inhibitor on different stages of coxsackievirus life-cycle. We showed that inhibition of the ubiquitin/proteasome pathway did not affect virus entry and had no influence on viral protease proteolytic activities. However, viral RNA transcription and protein translation were markedly reduced after addition of proteasome inhibitors. We further demonstrate that ubiquitin/proteasome pathway-mediated viral replication does not appear to be related to changes in proteasome activities. Taken together, our data suggest that proteasome inhibitor reduces coxsackievirus replication through inhibition of viral RNA transcription and protein synthesis. Thus, proteasome inhibition may represent a novel therapeutic approach against myocarditis.
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PMID:Proteasome inhibition reduces coxsackievirus B3 replication in murine cardiomyocytes. 1287 59

The relation between myocardial functional changes and the apoptosis-related proteins in patients with dilated cardiomyopathy (DCM) has not yet been reported. The purpose of this study was to assess this issue through the use of dobutamine stress echocardiography. A total of 81 segments of left ventricles (from 6 patients with DCM) were collected in this study. Segments from another 5 patients who had died of noncardiac causes were used as the control. Apoptosis-related proteins (bax, bcl-2, and p53) and apoptosis were evaluated in these segments by immunocytochemical stain and terminal deoxynucleotidyl transferase-mediated DNA nick end-labeling assay. There were 26 segments with dobutamine-induced contractile reserve. There were significant differences in numbers of segments with overexpression of bcl-2 and bax in the study and control groups. However, p53 was not found in either group. The total terminal deoxynucleotidyl transferase-mediated DNA nick end-labeling-positive nuclei in explanted hearts of DCM was 0.73%. The myocardial contractile reserve was inversely associated with an overexpression of bcl-2 (P <.01) rather than bax. In conclusion, the expression of bax and bcl-2 proteins in patients with DCM is enhanced and independent of p53. Loss of contractile reserve is associated with overexpression of bcl-2 protein in failing myocardium.
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PMID:The correlation between expression of apoptosis-related proteins and myocardial functional reserve evaluated by dobutamine stress echocardiography in patients with dilated cardiomyopathy. 1293 Nov 4

Current evidence shows that cardiomyocyte apoptosis plays a central role in the pathogenesis of myocardial disease and that reactive oxygen species is critically responsible for mediating cardiomyocyte apoptosis in both ischemia-reperfusion injury and dilated cardiomyopathy. ARC (Apoptosis Repressor with Caspase recruitment domain) is an anti-apoptotic protein that is found abundantly in terminally differentiated cells such as cardiomyocytes. The ARC knock-out mouse developed larger infarct in response to ischemia-reperfusion and transitioned more rapidly and severely to dilated cardiomyopathy following aortic constriction. In addition, ARC protein levels are decreased in human dilated cardiomyopathy and when cardiomyocytes are exposed to oxidative stress in vitro, but the mechanisms regulating ARC protein levels are not known. Here we show that degradation of ARC is dependent on the p53-induced ubiquitin E3 ligase, MDM2. Oxidative stress reduced ARC levels and up-regulated MDM2. MDM2 directly accelerated ARC protein turnover via ubiquitination and proteasomal-dependent degradation. This activity requires a functioning MDM2 ring finger domain because the MDM2(C464A) mutant was unable to direct ARC degradation. Furthermore, ARC degradation requires MDM2, because MDM2 knock-out fibroblasts showed defective ARC degradation that could be rescued by MDM2. Proteasomal inhibitors rescued both MDM2 and H(2)O(2)-induced degradation of ARC and inhibited cardiomyocyte apoptosis. Dilated cardiomyopathic hearts from mice that have undergone transverse aortic banding have increased MDM2 levels associated with decreased ARC levels. We conclude that MDM2 is a critical regulator of ARC levels in cardiomyocytes. Prevention of MDM2-induced degradation of ARC represents a potential therapeutic target to prevent cardiomyocyte apoptosis.
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PMID:Ubiquitination and degradation of the anti-apoptotic protein ARC by MDM2. 1714 34

Treating cancer patients with chemotherapeutics, such as doxorubicin (Dox), cause dilated cardiomyopathy and congestive heart failure because of oxidative stress. On the other hand, heat shock factor-1 (HSF-1), a transcription factor for heat shock proteins (Hsps), is also known to be activated in response to oxidative stress. However, the possible role of HSF-1 activation and the resultant Hsp25 in chemotherapeutic-induced heart failure has not been investigated. Using HSF-1 wild-type (HSF-1(+/+)) and knock-out (HSF-1(-/-)) mice, we tested the hypothesis that activation of HSF-1 plays a role in the development of Dox-induced heart failure. Higher levels of Hsp25 and its phosphorylated forms were found in the failing hearts of Dox-treated HSF-1(+/+) mice. More than twofold increase in Hsp25 mRNA level was found in Dox-treated hearts. Proteomic analysis showed that there is accumulation and aggregation of Hsp25 in Dox-treated failing hearts. Additionally, Hsp25 was found to coimmunoprecipitate with p53 and vice versa. Further studies indicated that the Dox-induced higher levels of Hsp25 transactivated p53 leading to higher levels of the pro-apoptotic protein Bax, but other p53-related proteins remained unaltered. Moreover, HSF-1(-/-) mice showed significantly reduced Dox-induced heart failure and higher survival rate, and there was no change in Bax upon treating with Dox in HSF-1(-/-) mice. From these results we propose a novel mechanism for Dox-induced heart failure: increased expression of Hsp25 because of oxidant-induced activation of HSF-1 transactivates p53 to increase Bax levels, which leads to heart failure.
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PMID:Role of heat shock factor-1 activation in the doxorubicin-induced heart failure in mice. 2036 84

The etiology of heart failure in dilated cardiomyopathy involves multiple agents. The purpose of this study was to investigate the presence of apoptosis-related proteins p53, bcl-2, and the defects of force transmission in end-stage dilated cardiomyopathy. We studied myocardial samples from 20 hearts with histologic findings of dilated cardiomyopathy. Myocardial samples obtained from 10 normal hearts were used as controls. An immunohistochemical method was performed with the use of desmin, N-cadherin, p53, and bcl-2 antibodies. The expression of desmin and N-cadherin was much more pronounced in dilated cardiomyopathy, and both of them were arranged disorderly. On the other hand, increased expression of p53 is associated with progressive loss of myocytes by apoptosis in heart failure, and increased expression of bcl-2 represents a possible compensatory antiapoptotic mechanism. The increased amount and the irregular distribution of desmin and N-cadherin in dilated cardiomyopathy may compensate for the loss of cellular stability due to the loss of contractile material. These alterations contribute to the deterioration of contractile function in heart failure. Furthermore, the prevalence of an apoptotic or compensatory antiapoptotic mechanism may influence the evolution of heart failure in dilated cardiomyopathy.
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PMID:Apoptosis-related factors p53, bcl-2 and the defects of force transmission in dilated cardiomyopathy. 2059 80

Programmed cell death 5 (PDCD5) is a cytosolic protein suppressing growth of multiple types of cancer cells through activating p53. We hypothesized that PDCD5 plays an essential role in cardiac remodeling and function. PDCD5 was significantly up-regulated in the hearts from mice subjected to angiotensin II treatment or transverse aortic constriction. Thus, we generated transgenic mice over-expressing human PDCD5 under the control of alpha myosin heavy chain promoter to examine the role of PDCD5 in cardiac remodeling. Transgenic founder died spontaneously displayed enlarged heart. The high PDCD5 over-expressing line (10-fold) showed reduced survival rate, increase in heart weight normalized to body weight. Real-Time RT-PCR analysis revealed fetal gene program was up-regulated. Echocardiography and histopathological examination showed characteristics of dilated cardiomyopathy and heart failure in transgenic mice. Western blot and immunohistochemistry analysis showed autophagy was dramatically increased in transgenic mice as compared to WT littermates control mice, while apoptosis remained unchanged. The enhanced autophagy in high over-expressing line was associated with significant increase in p53 activity and its downstream target damage-regulated autophagy modulator expression. The low over-expressing line (3.5-fold) appeared normal, but was more susceptible to angiotensin II-induced cardiac hypertrophy. This study is the first providing evidence that PDCD5 plays an important role in cardiac remodeling.
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PMID:Involvement of autophagy in cardiac remodeling in transgenic mice with cardiac specific over-expression of human programmed cell death 5. 2225 91

ZASP is a cytoskeletal PDZ-LIM protein predominantly expressed in striated muscle. It forms multiprotein complexes and plays a pivotal role in the structural integrity of sarcomeres. Mutations in the ZASP protein are associated with myofibrillar myopathy, left ventricular non-compaction and dilated cardiomyopathy. The ablation of its murine homologue Cypher results in neonatal lethality. ZASP has several alternatively spliced isoforms, in this paper we clarify the nomenclature of its human isoforms as well as their dynamics and expression pattern in striated muscle. Interaction is demonstrated between ZASP and two new binding partners both of which have roles in signalling, regulation of gene expression and muscle differentiation; the mechanosensing protein Ankrd2 and the tumour suppressor protein p53. These proteins and ZASP form a triple complex that appears to facilitate poly-SUMOylation of p53. We also show the importance of two of its functional domains, the ZM-motif and the PDZ domain. The PDZ domain can bind directly to both Ankrd2 and p53 indicating that there is no competition between it and p53 for the same binding site on Ankrd2. However there is competition for this binding site between p53 and a region of the ZASP protein lacking the PDZ domain, but containing the ZM-motif. ZASP is negative regulator of p53 in transactivation experiments with the p53-responsive promoters, MDM2 and BAX. Mutations in the ZASP ZM-motif induce modification in protein turnover. In fact, two mutants, A165V and A171T, were not able to bind Ankrd2 and bound only poorly to alpha-actinin2. This is important since the A165V mutation is responsible for zaspopathy, a well characterized autosomal dominant distal myopathy. Although the mechanism by which this mutant causes disease is still unknown, this is the first indication of how a ZASP disease associated mutant protein differs from that of the wild type ZASP protein.
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PMID:ZASP interacts with the mechanosensing protein Ankrd2 and p53 in the signalling network of striated muscle. 2464 31

SIRT1, a mammalian ortholog of yeast silent information regulator 2 (Sir2), is an NAD(+)-dependent protein deacetylase that plays a critical role in the regulation of vascular function. The current study aims to investigate the functional significance of deacetylase activity of SIRT1 in heart. Here we show that the early postnatal hearts expressed the highest level of SIRT1 deacetylase activity compared to adult and aged hearts. We generated transgenic mice with cardiac-specific expression of a dominant-negative form of the human SIRT1 (SIRT1H363Y), which represses endogenous SIRT1 activity. The transgenic mice displayed dilated atrial and ventricular chambers, and died early in the postnatal period. Pathological, echocardiographic and molecular phenotype confirmed the presence of dilated cardiomyopathy. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling analysis revealed a greater abundance of apoptotic nuclei in the hearts of transgenic mice. Furthermore, we show that cardiomyocyte apoptosis caused by suppression of SIRT1 activity is, at least in part, due to increased p53 acetylation and upregulated Bax expression. These results indicate that dominant negative form of SIRT1 (SIRT1H363Y) overexpression in mouse hearts causes cardiomyocyte apoptosis and early-onset heart failure, suggesting a critical role of SIRT1 in preserving normal cardiac development during the early postnatal period.
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PMID:Overexpression of a dominant-negative mutant of SIRT1 in mouse heart causes cardiomyocyte apoptosis and early-onset heart failure. 2510 17


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