Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Treatment of cultured neonatal ventricular myocytes with oncogenic Ras increases their size and stimulates the re-expression of genes which are normally restricted to the fetal stage of ventricular development, including atrial natriuretic factor (ANF) and skeletal muscle (SkM)-alpha-actin. To determine which signalling pathways mediate these responses, myocytes were transfected with oncogenic (V12) Ras mutants which interact selectively with different effectors and their effects on luciferase (LUX) reporter plasmids were examined. V12 human Ras (V12HRas), itself, activated ANF-LUX 9. 6-fold, whereas mutants of V12HRas, which selectively stimulate Ral guanine nucleotide dissociation stimulator (Ral.GDS) (E37G), c-Raf (D38E) and phosphatidylinositol 3-kinase (PI-3-K; Y40C) enhanced ANF-LUX expression 3.0-, 3.7- and 1.7-fold respectively. The full response of ANF-LUX to V12HRas was restored by using a combination of the individual effector domain mutants. Likewise, SkM-alpha-actin-LUX expression was activated 12.0-, 3.5-, 4.5- and 3. 0-fold by V12HRas, E37G, D38E and Y40C respectively, and a similar pattern of activation was also observed using a c-fos serum-response element-LUX reporter gene. Cell size was also increased by each of the mutants, but simultaneous expression of all three mutant constructs was needed to reconstitute the full effect of V12HRas on cell size (50% increase). Transfection with a constitutively active mutant of PI-3-K (p110K227E) stimulated ANF-LUX, SkM-alpha-actin-LUX, c-fos-serum-response element-LUX and Rous sarcoma virus-LUX by 3.1-, 3.2-, 2.1- and 2.9-fold respectively, but the co-transfected cytomegalovirus-beta-galactosidase reporter gene was activated to a similar extent (1.9-fold). These results suggest that Raf, Ral.GDS and PI-3-K can all transduce transcriptional responses to V12HRas, but that the specific induction of genes associated with the hypertrophic response is not mediated through PI-3-K.
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PMID:Stimulation of gene expression in neonatal rat ventricular myocytes by Ras is mediated by Ral guanine nucleotide dissociation stimulator (Ral.GDS) and phosphatidylinositol 3-kinase in addition to Raf. 976 20

In this report, reporter gene beta-galactosidase (LacZ) was chosen to compare two different intramuscular gene transfer methods, direct injection and gene suture. Evidence showed that gene suture can produce a higher foreign gene express efficiency in skeletal muscle compared with the direct injection method. The highly efficient eukaryotic expressing vectors of human atrial natriuretic factor (ANF) were constructed (pcD2/pAdVAntage/hANF and pcDNA3/hANF), and in vivo ANF gene delivery was performed by intramuscular gene suture. The effects of ANF gene transfer on blood pressure and renal sodium and water excretion were studied in three models of hypertensive animals. Results showed that a marked decrease of mean arterial pressure (MAP) and a significant increase of urine volume and urinary sodium excretion was produced in rats receiving the hANF construct due to the local expression of ANF and its secretion into plasma. Taken together, these results indicate that gene suture may represent a novel gene delivery modality in gene therapy.
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PMID:Gene suture--a novel method for intramuscular gene transfer and its application in hypertension therapy. 1057 91

We examined the intracellular signaling mechanism for tumor necrosis factor-alpha (TNF-alpha)-induced cardiac hypertrophy in isolated rat neonatal cardiomyocytes. TNF-alpha enhanced the expression of a kappa B-dependent reporter gene construct in a dose-dependent manner, which was transiently transfected in cardiomyocytes. Electrophoretic mobility shift assay demonstrated that TNF-alpha induced nuclear factor- kappa B (NF-kappa B)-specific DNA binding. Cultured cardiomyocytes were infected with a recombinant adenoviral vector expressing a degradation-resistant mutant of I kappa B alpha (AdI kappa B alpha 32/36A). The I kappa B alpha mutant suppressed NF-kappa B activation induced by TNF- alpha. In cardiomyocytes infected with AdI kappa B alpha 32/36A, TNF-alpha-induced hypertrophic responses, including increases in cell size, protein synthesis and atrial natriuretic factor production and enhancement of sarcomeric organization, were remarkably attenuated compared to the cells infected with an adenovirus expressing bacterial beta-galactosidase. Using a reactive oxygen species (ROS)-sensitive fluorescent dye, 2', 7'-dichlorofluorescin, we observed an increase in fluorescent signal in cardiomyocytes over time, upon addition of TNF-alpha. Preincubation of n-acetyl cysteine (NAC), an antioxidant, prior to TNF-alpha treatment, abolished TNF-alpha -induced ROS generation. NAC abolished TNF-alpha-induced NF-kappa B activation and hypertrophic responses. These findings indicated that TNF-alpha-induced cardiomyocyte hypertrophy is mediated through NF-kappa B activation via the generation of ROS.
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PMID:Involvement of reactive oxygen species-mediated NF-kappa B activation in TNF-alpha-induced cardiomyocyte hypertrophy. 1185 62

Protein kinase C (PKC) isoenzymes play a critical role in cardiomyocyte hypertrophy. At least three different phorbol ester-sensitive PKC isoenzymes are expressed in neonatal rat ventricular myocytes (NRVMs): PKC-alpha, -delta, and -epsilon. Using replication-defective adenoviruses (AdVs) that express wild-type (WT) and dominant-negative (DN) PKC-alpha together with phorbol myristate acetate (PMA), which is a hypertrophic agonist and activator of all three PKC isoenzymes, we studied the role of PKC-alpha in signaling-specific aspects of the hypertrophic phenotype. PMA induced nuclear translocation of endogenous and AdV-WT PKC-alpha in NRVMs. WT PKC-alpha overexpression increased protein synthesis and the protein-to-DNA (P/D) ratio but did not affect cell surface area (CSA) or cell shape compared with uninfected or control AdV beta-galactosidase (AdV betagal)-infected cells. PMA-treated uninfected cells displayed increased protein synthesis, P/D ratio, and CSA and elongated morphology. PMA did not further enhance protein synthesis or P/D ratio in AdV-WT PKC-alpha-infected cells. To assess the requirement of PKC-alpha for these PMA-induced changes, AdV-DN PKC-alpha or AdV betagal-infected NRVMs were stimulated with PMA. Without PMA, AdV-DN PKC-alpha had no effects on protein synthesis, P/D ratio, CSA, or shape vs. AdV betagal-infected NRVMs. PMA increased protein synthesis, P/D ratio, and CSA in AdV betagal-infected cells, but these parameters were significantly reduced in PMA-stimulated AdV-DN PKC-alpha-infected NRVMs. Overexpression of DN PKC-alpha enhanced PMA-induced cell elongation. Neither WT PKC-alpha nor DN PKC-alpha affected atrial natriuretic factor gene expression. Insulin-like growth factor-1 also induced nuclear translocation of endogenous PKC-alpha. PMA but not WT PKC-alpha overexpression induced ERK1/2 activation. However, AdV-DN PKC-alpha partially blocked PMA-induced ERK activation. Thus PKC-alpha is necessary for certain aspects of PMA-induced NRVM hypertrophy.
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PMID:Protein kinase C-alpha-induced hypertrophy of neonatal rat ventricular myocytes. 1527 71