| 1. |
- Ahmad, Faiyaz, et al.
(författare)
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Adenovirus-mediated overexpression of murine cyclic nucleotide phosphodiesterase 3B
- 2005
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Ingår i: Methods in molecular biology (Clifton, N.J.). - New Jersey : Humana Press. - 1940-6029 .- 1064-3745. ; 307, s. 93-107
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- To construct the recombinant adenovirus vector containing the cDNA for recombinant mouse cyclic nucleotide phosphodiesterase 3B (mPDE3B), the cDNA for mPDE3B was subcloned into pACCMV.pLpA. Subsequently, this recombinant plasmid, pACCMV.mPDE3B, was cotransfected with pJM17 plasmid containing the adenoviral genome into 293 human embryonic kidney cells, and the replication-deficient adenovirus AdCMV.mPDE3B was generated via homologous recombination. Large-scale preparation of adenovirus yielded 10(11)-10(13) viral particles/mL and could be quantitated by real-time polymerase chain reaction using iCycler (Bio-Rad). Efficiency of gene transfer was assessed by infecting FDCP2 or H4IIE cells with a recombinant adenovirus expressing beta-galactosidase (beta-gal); greater than 75% of cells were infected. Expression of mPDE3B in H4IIE hepatoma cells, FDCP2 hematopoietic cells, and beta-cells from isolated pancreatic islets was detected by Western blot analysis. In lysates from FDCP2 cells and H4IIE hepatoma cells infected with recombinant adenoviral mPDE3B constructs, mPDE3B activity was increased 10- to 30-fold compared with the activity in lysates from cells infected with beta-gal adenovirus. Stimulation of FDCP2 cells infected with mPDE3B adenovirus with insulin (100 nM, 10 min) resulted in an approx 1.7-fold increase in endogenous PDE3B and recombinant wild-type PDE3B activities. Infection of rat pancreatic islets resulted in a 5- to 10-fold increase in PDE3B expression and activity and subsequent blunting of insulin secretion. Thus, adenovirus-mediated gene transfer is effective for studying expression and regulation of recombinant PDE3 in insulin-responsive cells as well as insulin-secreting cells.
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| 2. |
- Ahmad, Faiyaz, et al.
(författare)
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Differential regulation of adipocyte PDE3B in distinct membrane compartments by insulin and the beta(3)-adrenergic receptor agonist CL316243: effects of caveolin-1 knockdown on formation/maintenance of macromolecular signalling complexes
- 2009
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Ingår i: BIOCHEMICAL JOURNAL. - 0264-6021. ; 424:3, s. 399-410
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Tidskriftsartikel (refereegranskat)abstract
- In adipocytes, PDE3B (phosphodiesterase 3B) is an important regulatory effector in signalling pathways controlled by insulin and cAMP-increasing hormones. Stimulation of 3T3-L1 adipocytes with insulin or the beta(3)-adrenergic receptor agonist CL316243 (termed CL) indicated that insulin preferentially phosphorylated/activated PDE3B associated with internal membranes (endoplasmic reticulum/Golgi), whereas CL preferentially phosphorylated/activated PDE3B associated with caveolae. siRNA (small interfering RNA)-mediated KD (knockdown) of CAV-1 (caveolin-1) in 3T3-L1 adipocytes resulted in down-regulation of expression of membrane-associated PDE3B. Insulin-induced activation of PDE3B was reduced, whereas CL-mediated activation was almost totally abolished. Similar results were obtained in adipocytes from Cav-1-deficient mice. siRNA-mediated KID of CAV-1 in 3T3-L1 adipocytes also resulted in inhibition of CL-stimulated phosphorylation of HSL (hormone-sensitive lipase) and perilipin A, and of lipolysis. Superose 6 gel-filtration chromatography of solubilized membrane proteins from adipocytes stimulated with insulin or CL demonstrated the reversible assembly of distinct macromolecular complexes that contained P-32-phosphorylated PDE3B and signalling molecules thought to be involved in its activation. Insulin- and CL-induced macromolecular complexes were enriched in cholesterol, and contained certain common signalling proteins [14-3-3, PP2A (protein phosphatase 2A) and cav-1]. The complexes present in insulin-stimulated cells contained tyrosine-phosphorylated IRS-1 (insulin receptor substrate 1) and its downstream signalling proteins, whereas CL-activated complexes contained beta(3)-adrenergic receptor, PKA-RII [PKA (cAMP-dependent protein kinase)-regulatory subunit] and HSL. Insulin- and CL-mediated macromolecular complex formation was significantly inhibited by CAV-1 KID. These results suggest that cav-1 acts as a molecular chaperone or scaffolding molecule in cholesterol-rich lipid rafts that may be necessary for the proper stabilization and activation of PDE3B in response to CL and insulin.
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| 3. |
- Ahmad, Faiyaz, et al.
(författare)
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Insulin-induced formation of macromolecular complexes involved in activation of cyclic nucleotide phosphodiesterase 3B (PDE3B) and its interaction with PKB
- 2007
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Ingår i: Biochemical Journal. - 0264-6021. ; 404, s. 257-268
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Tidskriftsartikel (refereegranskat)abstract
- Fractionation of 3T3-L1 adipocyte membranes revealed that PDE3B (phosphodiesterase 3B) was associated with PM (plasma membrane) and ER (endoplasmic reticulum)/Golgi fractions, that insulin-induced phosphorylation/activation of PDE3B was greater in internal membranes than PM fractions, and that there was no significant translocation of PDE3B between membrane fractions. Insulin also induced formation of large macromolecular complexes, separated during gel filtration (Superose 6 columns) of solubilized membranes, which apparently contain phosphorylated/activated PDE3B and signalling molecules potentially involved in its activation by insulin, e.g. IRS-1 (insulin receptor substrate-1), IRS-2, PI3K p85 [p85-subunit of PI3K (phospho-inosifide 3-kinase)], PKB (protein kinase B), HSP-90 (heat-shock protein 90) and 14-3-3. Expression of full-length recombinant FLAG-tagged murine (M) PDE3B and M3B Delta 604 (MPDE3B lacking N-terminal 604 amino acids) indicated that the N-terminal region of MPDE3B was necessary for insulin-induced activation and recruitment of PDE3B. siRNA (small interfering RNA) knock-down of PDE3B indicated that PDE3B was not required for formation of insulin-induced complexes. Wortmannin inhibited insulin-induced assembly of macromolecular complexes, as well as phosphorylation/activation of PKB and PDE3B, and their coimmunoprecipitation. Another PI3K inhibitor, LY294002, and the tyrosine kinase inhibitor, Genistein, also inhibited insulin-induced activation of PDE3B and its co-immunoprecipitation with PKB. Confocal microscopy indicated co-localization of PDE3B and PKB. Recombinant MPDE3B co-immunoprecipitated, and co-eluted during Superose 12 chromatography, to a greater extent with recombinant pPKB (phosphorylated/activated PKB) than dephospho-PKB or p-Delta PKB [pPKB lacking its PH domain (pleckstrin homology domain)]. Truncated recombinant MPDE3B proteins and pPKB did not efficiently co-immunoprecipitate, suggesting that structural determinants for their interaction reside in, or are regulated by, the N-terminal portion of MPDE3B. Recruitment of PDE3B in macromolecular complexes may be critical for regulation of specific cAMP pools and signalling pathways by insulin, e.g. lipolysis.
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| 4. |
- Ahmad, Faiyaz, et al.
(författare)
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Regulation of SERCA2 activity by PDE3A in human myocardium: Phosphorylation-dependent interaction of PDE3A1 with SERCA2.
- 2015
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 290:11, s. 6763-6776
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Tidskriftsartikel (refereegranskat)abstract
- PDE3 regulates cAMP-mediated signaling in the heart, and PDE3 inhibitors augment contractility in patients with heart failure. Studies in mice showed that PDE3A, not PDE3B, is the subfamily responsible for these inotropic effects, and that murine PDE3A1 associates with SERCA2, PLB and AKAP18 in a multi-protein signalosome in human SR. Immunohistochemical staining demonstrated that PDE3A co-localizes in Z-bands of human cardiac myocytes with desmin, SERCA2, PLB and AKAP18. In human SR fractions, cAMP increased PLB phosphorylation and SERCA2 activity; this was potentiated by PDE3 inhibition but not by PDE4 inhibition. During gel-filtration chromatography of solubilized SR membranes, PDE3 activity was recovered in distinct HMW and LMW peaks. HMW peaks contained PDE3A1 and PDE3A2, while LMW peaks contained PDE3A1, PDE3A2 and PDE3A3. Western blotting showed that endogenous HMW PDE3A1 was the principal PKA-phosphorylated isoform. Phosphorylation of endogenous PDE3A by rPKAc increased cAMP-hydrolytic activity, correlated with shift of PDE3A from LMW to HMW peaks, and increased co-immumoprecipitation of SERCA2, cav3, PKARII, PP2A and AKAP18 with PDE3A. In experiments with recombinant proteins, phosphorylation of rhPDE3A isoforms by rPKAc increased co-immumoprecipitation with rSERCA2 and rAKAP18. Deletion of the rhPDE3A1/PDE3A2 N-terminus blocked interactions with rSERCA2. Serine-to-alanine substitutions identified S292/S293, a site unique to hPDE3A1, as the principal site regulating its interaction with SERCA2. These results indicate that phosphorylation of hPDE3A1 at a PKA site in its unique N-terminal extension promotes its incorporation into SERCA2/AKAP18 signalosomes, where it regulates a discrete cAMP pool that controls contractility by modulating phosphorylation-dependent protein-protein interactions, PLB phosphorylation and SERCA2 activity.
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| 5. |
- Choi, Young Hun, et al.
(författare)
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Alterations in regulation of energy homeostasis in cyclic nucleotide phosphodiesterase 3B-null mice
- 2006
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Ingår i: Journal of Clinical Investigation. - 0021-9738. ; 116:12, s. 3240-3251
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Tidskriftsartikel (refereegranskat)abstract
- Cyclic nucleotide phosphodiesterase 3B (PDE3B) has been suggested to be critical for mediating insulin/IGF-1 inhibition of cAMP signaling in adipocytes, liver, and pancreatic beta cells. In Pde3b-KO adipocytes we found decreased adipocyte size, unchanged insulin-stimulated phosphorylation of protein kinase B and activation of glucose uptake, enhanced catecholamine-stimulated lipolysis and insulin-stimulated hpogenesis, and blocked insulin inhibition of catecholamine-stimulated lipolysis. Glucose, alone or in combination with glucagon-like peptide-1, increased insulin secretion more in isolated pancreatic KO islets, although islet size and morphology and immunoreactive insulin and glucagon levels were unchanged. The beta(3)-adrenergic agonist CL 316,243 (CL) increased lipolysis and serum insulin more in KO mice, but blood glucose reduction was less in CL-treated KO mice. Insulin resistance was observed in KO mice, with liver an important site of alterations in insulin-sensitive glucose production. In KO mice, liver triglyceride and cAMP contents were increased, and the liver content and phosphorylation states of several insulin signaling, gluconeogenic, and inflammation- and stress-related components were altered. Thus, PDE3B may be important in regulating certain cAMP signaling pathways, including lipolysis, insulin-induced antilipolysis, and cAMP-mediated insulin secretion. Altered expression and/or regulation of PDE3B may contribute to metabolic dysregulation, including systemic insulin resistance.
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| 6. |
- Choi, Young-Hun, et al.
(författare)
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Identification of a novel isoform of the cyclic-nucleotide phosphodiesterase PDE3A expressed in vascular smooth-muscle myocytes
- 2001
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Ingår i: Biochemical Journal. - 0264-6021. ; 353:Pt 1, s. 41-50
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Tidskriftsartikel (refereegranskat)abstract
- We have identified a new cyclic-nucleotide phosphodiesterase isoform, PDE3A, and cloned its cDNA from cultured aortic myocytes. The nucleotide sequence of its coding region is similar to that of the previously cloned myocardial isoform except for the absence of the initial 300-400 nt that are present in the latter, as confirmed by reverse-transcriptase-mediated PCR, 5' rapid amplification of cDNA ends and a ribonuclease protection assay. Expression in Spodoptera frugiperda (Sf9) cells yields a protein with catalytic activity and inhibitor sensitivity typical of the PDE3 family. The recombinant protein's molecular mass of approx. 131 kDa is compatible with translation from an ATG sequence corresponding to nt 436-438 of the myocardial PDE3A coding region. Antibodies against residues 424-460 (nt 1270-1380) and 1125-1141 (nt 3373-3423) of the myocardial isoform react with an approx. 118 kDa band in Western blots of homogenates of human aortic myocytes, whereas antibodies against residues 29-42 (nt 85-126) do not react with any bands in these homogenates. Our results suggest that a vascular smooth-muscle isoform ('PDE3A2') is a product of the same gene as the longer myocardial ('PDE3A1') and the shorter placental ('PDE3A3') isoforms and is generated pre-translationally in a manner that results in the absence of the 145 N-terminal amino acids of PDE3A1.
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| 7. |
- Chung, Youn Wook, et al.
(författare)
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White to beige conversion in PDE3B KO adipose tissue through activation of AMPK signaling and mitochondrial function
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Understanding mechanisms by which a population of beige adipocytes is increased in white adipose tissue (WAT) reflects a potential strategy in the fight against obesity and diabetes. Cyclic adenosine monophosphate (cAMP) is very important in the development of the beige phenotype and activation of its thermogenic program. To study effects of cyclic nucleotides on energy homeostatic mechanisms, mice were generated by targeted inactivation of cyclic nucleotide phosphodiesterase 3b (Pde3b) gene, which encodes PDE3B, an enzyme that catalyzes hydrolysis of cAMP and cGMP and is highly expressed in tissues that regulate energy homeostasis, including adipose tissue, liver, and pancreas. In epididymal white adipose tissue (eWAT) of PDE3B KO mice on a SvJ129 background, cAMP/protein kinase A (PKA) and AMP-activated protein kinase (AMPK) signaling pathways are activated, resulting in "browning" phenotype, with a smaller increases in body weight under high-fat diet, smaller fat deposits, increased β-oxidation of fatty acids (FAO) and oxygen consumption. Results reported here suggest that PDE3B and/or its downstream signaling partners might be important regulators of energy metabolism in adipose tissue, and potential therapeutic targets for treating obesity, diabetes and their associated metabolic disorders.
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| 8. |
- Degerman, Eva, et al.
(författare)
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From PDE3B to the regulation of energy homeostasis.
- 2011
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Ingår i: Current Opinion in Pharmacology. - : Elsevier BV. - 1471-4973 .- 1471-4892. ; 11, s. 676-682
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Tidskriftsartikel (refereegranskat)abstract
- The incidence of obesity in the developed world is increasing at an alarming rate. Concurrent with the increase in the incidence of obesity is an increase in the incidence of type 2 diabetes. Cyclic AMP (cAMP) and cGMP are key second messengers in all cells; for example, when it comes to processes of relevance for the regulation of energy metabolism, cAMP is a key mediator in the regulation of lipolysis, glycogenolysis, gluconeogenesis and pancreatic β cell insulin secretion. PDE3B, one of several enzymes which hydrolyze cAMP and cGMP, is expressed in cells of importance for the regulation of energy homeostasis, including adipocytes, hepatocytes, hypothalamic cells and β cells. It has been shown, using PDE3 inhibitors and gene targeting approaches in cells and animals, that altered levels of PDE3B result in a number of changes in the regulation of glucose and lipid metabolism and in overall energy homeostasis. This article highlights the complexity involved in the regulation of PDE3B by hormones, and in the regulation of downstream metabolic effects by PDE3B in several interacting tissues.
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| 9. |
- Guirguis, Emilia, et al.
(författare)
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A Role for Phosphodiesterase 3B in Acquisition of Brown Fat Characteristics by White Adipose Tissue in Male Mice.
- 2013
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 154:9, s. 3152-3167
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Tidskriftsartikel (refereegranskat)abstract
- Obesity is linked to various diseases, including insulin resistance, diabetes, and cardiovascular disorders. The idea of inducing white adipose tissue (WAT) to assume characteristics of brown adipose tissue (BAT), and thus gearing it to fat-burning instead of storage, is receiving serious consideration as potential treatment for obesity and related disorders. Phosphodiesterase 3B (PDE3B) links insulin- and cAMP-signaling networks in tissues associated with energy metabolism, including WAT. We utilized C57BL/6 PDE3B knockout (KO) mice to elucidate mechanisms involved in the formation of BAT in epididymal WAT (EWAT) depots. Examination of gene expression profiles in PDE3B KO EWAT revealed increased expression of several genes that block white and promote brown adipogenesis, such as C-terminal binding protein (Ctbp), bone morphogenetic protein 7 (Bmp7) and PR domain containing 16 (Prdm16), but a clear BAT-like phenotype was not completely induced. However, acute treatment of PDE3B KO mice with the β3-adrenergic agonist, CL316243, markedly increased expression of cyclooxygenase-2 (COX-2), which catalyzes prostaglandin synthesis and is thought to be important in formation of BAT in WAT, and of elongation of very long chain fatty acids 3 (Elovl3), which is linked to BAT recruitment upon cold exposure, causing a clear shift toward fat-burning and induction of BAT in KO EWAT. These data provide insight into mechanisms of BAT formation in mouse EWAT, suggesting that, in C57BL/6 background, an increase in cAMP, caused by ablation of PDE3B and administration of CL316243, may promote differentiation of prostaglandin-responsive progenitor cells in the EWAT stromal vascular fraction into functional brown adipocytes.
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| 10. |
- Lindh, Rebecka, et al.
(författare)
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Multisite phosphorylation of adipocyte and hepatocyte phosphodiesterase 3B.
- 2007
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Ingår i: Biochimica et Biophysica Acta: Molecular Cell Research. - : Elsevier BV. - 0167-4889. ; 1773:4, s. 584-592
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Tidskriftsartikel (refereegranskat)abstract
- Phosphodiesterase 3B (PDE3B) is an important component of insulin and cAMP-dependent signalling pathways. In order to study phosphorylation of PDE3B, we have used an adenoviral system to express recombinant flag-tagged PDE3B in primary rat adipocytes and H4IIE hepatoma cells. Phosphorylation of PDE3B after treatment of cells with insulin, cAMP-increasing agents, or the phosphatase inhibitor, calyculin A was analyzed by two-dimensional tryptic phosphopeptide mapping and mass spectrometry. We found that PDE3B is multisite phosphorylated in adipocytes and H4IIE hepatoma cells in response to all these stimuli. Several sites were identified; serine (S)273, S296, S421, S424/5, S474 and S536 were phosphorylated in adipocyte as well as H4IIE hepatoma cells whereas S277 and S507 were phosphorylated in hepatoma cells only. Several of the sites were phosphorylated by insulin as well as cAMP-increasing hormones indicating integration of the two signalling pathways upstream of PDE3B, maybe at the level of protein kinase B.
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