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V Manganiello

Publications and source records attributed to V Manganiello.

33 records · Page 2Linked to original sources
PubMed1992

Molecular cloning and expression of human myocardial cGMP-inhibited cAMP phosphodiesterase.

We have cloned a cDNA for a myocardial cGMP-inhibited cAMP phosphodiesterase (cGI PDE) from a human heart cDNA library in lambda Zap II. The open reading frame [3.5 kilobases (kb)] of cDNA clone n.13.2 (7.7 kb) encodes a protein of 125 kDa. In Northern blots of total human ventricle RNA, a single mRNA species (8.3 kb) hybridized with a 4-kb EcoRI restriction fragment of clone n.13.2 cDNA (containing the entire open reading frame). The carboxyl-terminal region of the deduced amino acid sequence of the cGI PDE contains the putative catalytic domain conserved among mammalian PDE families. A partial cDNA clone, n.2, encoding a truncated, 54-kDa cGI PDE containing the conserved domain was expressed as a catalytically active fusion protein in Escherichia coli. cAMP hydrolytic activity was inhibited by cGMP and OPC 3911 but not by rolipram. Thus, this report provides direct proof that the conserved domain contains the catalytic core of cGI PDEs.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1991

Selective inhibition of cGMP-inhibited and cGMP-noninhibited cyclic nucleotide phosphodiesterases and relaxation of rat aorta.

In the supernatant (50,000 g, 1 hr) fraction from rat aortic smooth muscle homogenates, approximately 50% of total cAMPE PDE activity was inhibited by OPC 3911 (3 microM), while approximately 20% was inhibited by rolipram (30 microM). A cGMP-inhibited cyclic nucleotide phosphodiesterase (cGI-PDE) was further purified using DEAE chromatography followed by affinity chromatography on the N-(2-isothiocyanato)ethyl derivative of cilostamide conjugated to aminoethyl agarose (CIT-agarose). OPC 3911, CI-930, and milrinone, but not rolipram, were potent and selective inhibitors of this enzyme. The PDE-activity in the CIT-agarose flow through fraction (RI-PDE), however, was inhibited potently by rolipram, but not by cGMP, OPC 3911, CI-930 or milrinone. Functional studies showed that OPC 3911, CI-930, and milrinone were potent relaxants of contracted rat aorta. Rolipram had little relaxant effect. When OPC 3911 or milrinone was combined with rolipram more than additive effects on aortic relaxation and cAMP content were obtained. OPC 3911 combined with milrinone had only additive effects. These results demonstrate the presence of a cGI-PDE in rat aortic smooth muscle, and that inhibition of this isozyme may be of primary importance for the relaxant effects of OPC 3911, CI-930, and milrinone. A RI-PDE activity was also found, but it appeared to be less important for modulation of vascular tone unless the cGI-PDE was already inhibited. This may explain the synergistic relaxant effects observed when both PDE-isozymes were inhibited.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1990

Characterization of particulate cyclic nucleotide phosphodiesterases from bovine brain: purification of a distinct cGMP-stimulated isoenzyme.

In the absence of detergent, approximately 80-85% of the total cGMP-stimulated phosphodiesterase (PDE) activity in bovine brain was associated with washed particulate fractions; approximately 85-90% of the calmodulin-sensitive PDE was soluble. Particulate cGMP-stimulated PDE was higher in cerebral cortical gray matter than in other regions. Homogenization of the brain particulate fraction in 1% Lubrol increased cGMP-stimulated activity approximately 100% and calmodulin-stimulated approximately 400-500%. Although 1% Lubrol readily solubilized these PDE activities, approximately 75% of the cAMP PDE activity (0.5 microM [3H]cAMP) that was not affected by cGMP was not solubilized. This cAMP PDE activity was very sensitive to inhibition by Rolipram but not cilostamide. Thus, three different PDE types, i.e., cGMP stimulated, calmodulin sensitive, and Rolipram inhibited, are associated in different ways with crude bovine brain particulate fractions. After solubilization and purification by chromatography on cGMP-agarose, heparin-agarose, and Superose 6, the brain particulate cGMP-stimulated PDE cross-reacted with antibody raised against a cGMP-stimulated PDE purified from calf liver supernatant. The brain enzyme exhibited a slightly greater subunit Mr than did soluble forms from calf liver or bovine brain, as evidenced by protein staining or immunoblotting after polyacrylamide gel electrophoresis under denaturing conditions. Incubation of brain particulate and liver soluble cGMP-stimulated PDEs with V8 protease produced several peptides of similar size, as well as at least two distinct fragments of approximately 27 kDa from the brain and approximately 23 kDa from the liver enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1981

Presence of autoantibody for phospholipase inhibitory protein, lipomodulin, in patients with rheumatic diseases.

The activity of phospholipase inhibitory protein, lipomodulin, partially purified from rabbit neutrophils, was markedly decreased after treatment with sera from patients with rheumatic diseases such as systemic lupus erythematosus, rheumatoid arthritis, and dermatomyositis. The decrease of the protein's inhibitory activity on phospholipase A2 paralleled the amount of [35S]methionine-labeled lipomodulin precipitated by the sera. Absorption of patients' sera with anti-human IgM (mu chain) or protein A-agarose, but not with anti-human IgG (gamma chain), decreased their ability to decrease the activity of lipomodulin on phospholipase A2 or to precipitate the radioactive lipomodulin. The IgM fraction of patients' sera could precipitate [35S]methionine-labeled lipomodulin (40,000 daltons) which comigrated with highly purified lipomodulin on gel electrophoresis with sodium dodecyl sulfate. All of these observations suggest that the sera of many patients with rheumatic diseases contain autoantibody against lipomodulin. A monoclonal antibody against lipomodulin was also obtained. Stimulating human fibroblasts with bradykinin in the presence of monoclonal antilipomodulin antibody markedly enhanced arachidonic acid release due to the activation of phospholipase(s) in the intact cells, and this stimulatory effect was blocked by adding purified lipomodulin. These findings suggest that lipomodulin regulates the activity of phospholipase(s) on the cell surface and that autoantibodies against lipomodulin may play a role in certain symptoms of rheumatic diseases, especially by the formation of prostaglandins and other metabolites of arachidonic acid.

Animals↗
PubMed1972

An effect of dexamethasone on adenosine 3',5'-monophosphate content and adenosine 3',5'-monophosphate phosphodiesterase activity of cultured hepatoma cells.

The effect of dexamethasone on adenosine 3',5'-monophosphate (cAMP) phosphodiesterase activity in cultured HTC hepatoma cells was investigated. Homogenates of these cells contain phosphodiesterase activity with two apparent Michaelis constants for cAMP (2-5 mum and 50 mum). At all substrate concentrations tested, phosphodiesterase activity was decreased 25-40% in cells incubated for 36 hr or more with 1 mum dexamethasone. Acid phosphatase activity in the same cells was not decreased. alpha-Methyl testosterone, 1 mum, was without effect on phosphodiesterase activity. Incubation for 10 min with epinephrine plus theophylline increased the cAMP content of the HTC cells 3- to 6-fold. In cells incubated for 72 hr with dexamethasone, the basal concentration of cAMP was slightly increased and the increment produced by epinephrine plus theophylline was markedly increased. We believe that in many cells the so-called permissive effects of steroid hormones on cAMP mediated processes may be due to an effect of these hormones on cAMP phosphodiesterase activity similar to that observed in HTC cells incubated with dexamethasone.

Acid Phosphatase↗
PubMed1972

Selective loss of adipose cell responsiveness to glucagon with growth in the rat.

In isolated fat cells, the same maximal rate of glycerol production can be induced by epinephrine or ACTH, alone or in combination with each other or with glucagon. With fat cells from rats weighing 150-175 g, the maximal rate of lipolysis attained with glucagon was 75-80% of that produced by epinephrine or ACTH, and with increasing size of the donor rat, the magnitude of the effect of glucagon relative to that of the other hormones declined markedly. In particulate preparations from fat cells of rats weighing 100-125 g, the maximal effect of glucagon on adenyl cyclase activity was about 60% of that of epinephrine, and was significantly less (30%) in preparations from 350-400 g rats. These data are consistent with the hypothesis that with growth of the rat there is a selective decline in the number of glucagon receptors relative to those for epinephrine or ACTH in the fat cell membrane.

Adenosine Triphosphate↗
PubMed1971

A simple, sensitive protein-binding assay for guanosine 3':5'-monophosphate.

A protein-binding assay for guanosine 3':5'-monophosphate, which employs an enzyme preparation from lobster tail muscle, is described. The binding constant for cyclic GMP was 2-10 nM for four different enzyme preparations. The method can be set up in several days and permits the detection of as little as 0.5-1 pmol of cyclic GMP. In some instances, it is possible to assay the nucleotide in urine or deproteinized extracts of tissue without purification. For other samples, a simple method for separating and purifying cyclic AMP and cyclic GMP is described.

Animals↗
PubMed1971

The effect of polystyrene beads on cyclic 3',5'-adenosine monophosphate concentration in leukocytes.

After incubation with polystyrene latex beads for 5 min. the cyclic 3',5'-adenosine monophosphate (cyclic AMP) content of human peripheral blood leukocyte suspensions was increased severalfold. Preparations enriched in mononuclear cells and containing only 0-20% polymorphonuclear leukocytes (PMN) and no visible platelets exhibited a quantitatively similar response. Purified fractions of cells containing 85-90% PMN responded to polystyrene beads with a much smaller increase in cyclic AMP content. Phagocytosis of paraffin oil emulsion in the unfractionated mixed human leukocyte preparation was associated with little or no change in cyclic AMP levels. There was no change in cyclic AMP content of rabbit alveolar macrophages or guinea pig PMN during phagocytosis of polystyrene beads. All of these observations are consistent with the view that particle uptake per se does not increase cyclic AMP levels in phagocytic cells. It seems probable that the increase in cyclic AMP concentration that results when unfractionated human blood leukocytes are incubated with polystyrene beads occurs in cells other than PMN.

Animals↗