Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A subset of cyclin-dependent protein kinases--Cdk7, Cdk8, and Cdk9--participates directly, in complex ways, with the fundamental machinery for gene transcription, as elements of general transcription factors whose substrate is the C-terminal domain (CTD) of RNA polymerase II. Here, we review recent data implicating the CTD kinase Cdk9 as a critical determinant of cardiac hypertrophy, in vitro and in vivo. Diverse trophic signals that increase cardiac mass all activated Cdk9 (work load, the small G-protein Gaq, and the calcium-dependent phosphatase calcineurin in mouse myocardium; endothelin-1, a hypertrophic agonist, in cultured cardiomyocytes). Little or no change occurred in levels of the kinase or its activator, cyclin T. Instead, in all four hypertrophic models, Cdk9 activation involves the dissociation of 7SK small nuclear RNA (snRNA), an endogenous inhibitor. In culture, dominant-negative Cdk9 blocked ET-1-induced hypertrophy, whereas an anti-sense "knockdown" of 7SK snRNA provoked spontaneous cell growth. In trans-genie mice, concordant with these results, activation of Cdk9 activity via cardiac-specific overexpression of cyclin Tl suffices to provoke hypertrophy. Together, these findings implicate Cdk9 activity as a pivotal regulator of pathophysiological heart growth. Because hypertrophy, in turn, is a cardinal risk factor for developing cardiac pump failure, these results support the logic of examining Cdk9 as a potential drug target in heart disease.
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PMID:Cyclins that don't cycle--cyclin T/cyclin-dependent kinase-9 determines cardiac muscle cell size. 1269 56

Consumption of tea (Camellia sinensis) has been suggested to prevent cancer, heart disease and other diseases. Animal studies have shown that tea and tea constituents inhibit carcinogenesis of the skin, lung, oral cavity, esophagus, stomach, liver, prostate and other organs. In some studies, the inhibition correlated with an increase in tumor cell apoptosis and a decrease in cell proliferation. Studies with human cancer cell lines have demonstrated that epigallocatechin-3-gallate (EGCG), a major tea polyphenol, inhibits mitogen-activated protein kinases, cyclin-dependent kinases, growth factor-related cell signaling, activation of activator protein 1 (AP-1) and nuclear factor kappaB (NFkappaB), topoisomerase I and matrix metalloproteinases as well as other potential targets. Although some studies report effects of EGCG at submicromolar levels, most experiments require concentrations of >10 or 20 micromol/L to demonstrate the effect. In humans, tea polyphenols undergo glucuronidation, sulfation, methylation, and ring fission. The peak plasma concentration of EGCG is approximately 1 micromol/L. The possible relevance of each of the proposed mechanisms to human cancer prevention is discussed in light of current bioavailability data for tea polyphenols and the potential limitations of animal models of carcinogenesis. Such discussion, it is hoped, will clarify some misunderstandings of cancer prevention by tea and stimulate new research efforts.
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PMID:Mechanisms of cancer prevention by tea constituents. 1451 24

Defects of atrial and ventricular septation are the most frequent form of congenital heart disease, accounting for almost 50% of all cases. We previously reported that a heterozygous G296S missense mutation of GATA4 caused atrial and ventricular septal defects and pulmonary valve stenosis in humans. GATA4 encodes a cardiac transcription factor, and when deleted in mice it results in cardiac bifida and lethality by embryonic day (E)9.5. In vitro, the mutant GATA4 protein has a reduced DNA binding affinity and transcriptional activity and abolishes a physical interaction with TBX5, a transcription factor critical for normal heart formation. To characterize the mutation in vivo, we generated mice harboring the same mutation, Gata4 G295S. Mice homozygous for the Gata4 G295S mutant allele have normal ventral body patterning and heart looping, but have a thin ventricular myocardium, single ventricular chamber, and lethality by E11.5. While heterozygous Gata4 G295S mutant mice are viable, a subset of these mice have semilunar valve stenosis and small defects of the atrial septum. Gene expression studies of homozygous mutant mice suggest the G295S protein can sufficiently activate downstream targets of Gata4 in the endoderm but not in the developing heart. Cardiomyocyte proliferation deficits and decreased cardiac expression of CCND2, a member of the cyclin family and a direct target of Gata4, were found in embryos both homozygous and heterozygous for the Gata4 G295S allele. To further define functions of the Gata4 G295S mutation in vivo, compound mutant mice were generated in which specific cell lineages harbored both the Gata4 G295S mutant and Gata4 null alleles. Examination of these mice demonstrated that the Gata4 G295S protein has functional deficits in early myocardial development. In summary, the Gata4 G295S mutation functions as a hypomorph in vivo and leads to defects in cardiomyocyte proliferation during embryogenesis, which may contribute to the development of congenital heart defects in humans.
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PMID:Congenital heart disease-causing Gata4 mutation displays functional deficits in vivo. 2258 35

The G1 cyclins play a pivotal role in regulation of cell differentiation and proliferation. The mechanisms underlying their cell-specific roles are incompletely understood. Here, we show that a G1 cyclin, cyclin D2 (CycD2), enhances the activity of transcription factor GATA4, a key regulator of cardiomyocyte growth and differentiation. GATA4 recruits CycD2 to its target promoters, and their interaction results in synergistic activation of GATA-dependent transcription. This effect is specific to CycD2 because CycD1 is unable to potentiate activity of GATA4 and is CDK-independent. GATA4 physically interacts with CycD2 through a discreet N-terminal activation domain that is essential for the cardiogenic activity of GATA4. Human mutations in this domain that are linked to congenital heart disease interfere with CycD2-GATA4 synergy. Cardiogenesis assays in Xenopus embryos indicate that CycD2 enhances the cardiogenic function of GATA4. Together, our data uncover a role for CycD2 as a cardiogenic coactivator of GATA4 and suggest a paradigm for cell-specific effects of cyclin Ds.
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PMID:Cyclin D2 is a GATA4 cofactor in cardiogenesis. 2447 67