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Background: The phosphodiesterase 3A (PDE3A) gene encodes a PDE that regulates cardiac myocyte cyclic adenosine monophosphate (cAMP) levels and myocardial contractile function. PDE3 inhibitors (PDE3i) are used for short-term treatment of refractory heart failure (HF), but do not produce uniform long-term benefit.Objectives: The authors tested the hypothesis that drug target genetic variation could explain clinical response heterogeneity to PDE3i in HF.Methods: PDE3A promoter studies were performed in a cloned luciferase construct. In human left ventricular (LV) preparations, mRNA expression was measured by reverse transcription polymerase chain reaction, and PDE3 enzyme activity by cAMP-hydrolysis.Results: The authors identified a 29-nucleotide (nt) insertion (INS)/deletion (DEL) polymorphism in the human PDE3A gene promoter beginning 2,214 nt upstream from the PDE3A1 translation start site. Transcription factor ATF3 binds to the INS and represses cAMP-dependent promoter activity. In explanted failing LVs that were homozygous for PDE3A DEL and had been treated with PDE3i pre-cardiac transplantation, PDE3A1 mRNA abundance and microsomal PDE3 enzyme activity were increased by 1.7-fold to 1.8-fold (p < 0.05) compared with DEL homozygotes not receiving PDE3i. The basis for the selective up-regulation in PDE3A gene expression in DEL homozygotes treated with PDE3i was a cAMP response element enhancer 61 nt downstream from the INS, which was repressed by INS. The DEL homozygous genotype frequency was also enriched in patients with HF.Conclusions: A 29-nt INS/DEL polymorphism in the PDE3A promoter regulates cAMP-induced PDE3A gene expression in patients treated with PDE3i. This molecular mechanism may explain response heterogeneity to this drug class, and may inform a pharmacogenetic strategy for a more effective use of PDE3i in HF. [ABSTRACT FROM AUTHOR]

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Metabolic disorders caused by impairments of the Gsα/cAMP/PKA pathway affecting the signaling of PTH/PTHrP lead to features caused by non-responsiveness of target organs, in turn leading to manifestations similar to the deficiency of the hormone itself. Pseudohypoparathyroidism (PHP) and related disorders derive from a defect of the α subunit of the stimulatory G protein (Gsα) or of downstream effectors of the same pathway, such as the PKA regulatory subunit 1A and the phosphodiesterase type 4D. The increasing knowledge on these diseases made the actual classification of PHP outdated as it does not include related conditions such as acrodysostosis (ACRDYS) or progressive osseous heteroplasia (POH), so that a new nomenclature and classification has been recently proposed grouping these disorders under the term "inactivating PTH/PTHrP signaling disorder" (iPPSD). This review will focus on the pathophysiology, clinical and molecular aspects of these rare, heterogeneous but closely related diseases. [ABSTRACT FROM AUTHOR]

A series of 40 7-(O-substituted)-2-morpholino-8-aryl-4H-benzo[ e ][1,3]oxazin-4-one derivatives was synthesized. They were prepared via synthesis of a key precursor, 8-bromo-7-hydroxy-2-morpholino-4H-benzo[ e ][1,3]oxazin-4-one 13 which was amenable to ether synthesis at the 7-position and Suzuki coupling at the 8-position. The 2 protons of 7-OCH 2 in compounds 18g , 18h , 18i , 18l and 18m prove to be magnetically non-equivalent, atropisomerism (axial chirality), as result of sterically hindered rotation of the bulky 8-aryl-substituent. The products were evaluated for their activities against PI3K isoforms, DNA-PK and PDE3. The results showed that this substitution pattern has a deleterious effect on PI3K activities, which may arise from steric hindrance in the active site. PI3Kδ was somewhat more tolerant of this substitution particularly where 8-(4-methoxylphenyl) substituents were present (IC 50 s ∼ 2–3 μM). Good activities against PDE3 were also obtained for compounds, with particular members of the 7-(2-pyridinyl) methoxy series 19 showing good inhibition (IC 50 s ∼ 2–3 μM), comparable to previously described analogues. A piperazinyl derivative 26a effectively inhibited ADP-induced platelet aggregation with an IC 50 of 8 μM. [ABSTRACT FROM AUTHOR]

Abstract: Phosphodiesterase type 3 (PDE3) is an important regulator of cAMP-mediated responses within the cardiovascular system. PDE3 exists as two subtypes: PDE3A and PDE3B, with distinct cellular and subcellular locations. Due to the lack of subtype-specific pharmacological tools, the definitive role of each subtype in regulating cardiovascular function has not been determined. In this study, we investigated platelet and cardiac function, using PDE3A and PDE3B gene knockout (KO) mice. Platelet-rich-plasma was prepared from the blood of KO and age-matched wild-type (WT) mice. PGE1 (1 μg/mL) almost completely inhibited aggregation of platelets from WT, PDE3A KO and PDE3B KO mice. In platelets from WT mice, cilostamide (100 μM), a selective PDE3 inhibitor, blocked collagen- and ADP-induced aggregation. In contrast, cilostamide had no effect on aggregation of platelets from PDE3A KO mice. In PDE3B KO mice, inhibition of collagen- and ADP-induced platelet aggregation was similar to that in WT mice. The resting intra-platelet cAMP concentration in platelets from PDE3A KO mice was twice that in the WT platelets. After PGE1 (0.1 μg/mL) stimulation, intra-cellular cAMP concentration was increased significantly more in platelets from PDE3A KO mice compared to WT mice. In vivo, PDE3A KO mice were protected against collagen/epinephrine-induced pulmonary thrombosis and death, while no such protection was observed in PDE3B KO mice. The heart rate of PDE3A KO mice was significantly higher, compared with age-matched WT mice, while that of PDE3B KO mice was similar to WT. There was no difference in cardiac contractility between PDE3A or PDE3B KO mice. Heart rate and contractility were increased in a similar dose-dependent fashion by isoproterenol in both types of KO mice. Cilostamide increased heart rate and contractility in WT and PDE3B KO but not in PDE3A KO mice. Compared to WT and PDE3B KO mice, cyclic AMP-PDE activity in membrane fractions prepared from the hearts of PDE3A KO mice was lower and not inhibited by cilostamide. The data suggest that PDE3A is the main subtype of PDE3 expressed in platelets and cardiac ventricular myocytes, and is responsible for the functional changes caused by PDE3 inhibition. [Copyright &y& Elsevier]

It is known that Di (2-ethylhexyl) phthalate (DEHP) may impact mammalian reproduction and that in females one target of the drug's action is follicle assembly. Here we revisited the phthalate's action on the ovary and from bioinformatics analyses of the transcriptome performed on newborn mouse ovaries exposed in vitro to DEHP, up-regulation of PDE3A, as one of the most important alterations caused by DEHP on early folliculogenesis, was identified. We obtained some evidence suggesting that the decrease of cAMP level in oocytes and the parallel decrease of PKA expression, consequent on the PDE3A increase, were a major cause of the reduction of follicle assembly in the DEHP-exposed ovaries. In fact, Pde3a RNAi on cultured ovaries reducing cAMP and PKA decrease counteracted the primordial follicle assembly impairment caused by the compound. Moreover, RNAi normalized the level of Kit, Nobox , Figla mRNA and GDF9, BMP15, CX37, γH2AX proteins in oocytes, and KitL transcripts in granulosa cells as well as their proliferation rate altered by DEHP exposure. Taken together, these results identify PDE3A as a new critical target of the deleterious effects of DEHP on early oogenesis in mammals and highlight cAMP-dependent pathways as major regulators of oocyte and granulosa cell activities crucial for follicle assembly. Moreover, we suggest that the level of intracellular cAMP in the oocytes may be an important determinant for their capability to repair DNA lesions caused by DNA damaging compounds including DEHP. Image 1 • DEHP exposure impairs the primordial follicle assembly of newborn mouse ovaries. • DEHP exposure promotes PDE3A expression in the early stage of folliculogenesis. • Pde3a RNAi counteracted the influence of DEHP on ovaries by reducing cAMP and PKA. PDE3A is one of the most important regulators caused by DEHP exposure on impairment of early folliculogenesis. [ABSTRACT FROM AUTHOR]

Hypertension and brachydactyly syndrome (HTNB; MIM 112410) is a rare, recently described, autosomal dominant syndromic disease characterized by the triad of brachydactyly type E (BDE), short stature, and hypertension. HTNB is caused by a heterozygous mutation in the PDE3A (MIM 123805) gene on chromosome 12p12; this gene encodes a member of the cGMP-inhibited cyclic nucleotide phosphodiesterase family. PED3A plays a role in many signal transduction pathways, including those involved in vascular smooth muscle proliferation and contraction, cardiac contractility, platelet aggregation, and hormone secretion. Here, we present a new case of HTNB in a 42-year-old patient who experienced recurrent ischemic strokes in various vascular territories; these strokes were caused by intracranial multiarterial dissection, and were experienced for 2 weeks. She was found to harbor a de novo heterozygous in-frame deletion, c.1333_1335del p.(Thr445del), in exon 4 of the PDE3A gene. Our finding is expected to contribute to the elucidation of the pathophysiology of stroke in HTNB patients. We further review all clinical and molecular genetic features of this rare disease described in the literature to date. [ABSTRACT FROM AUTHOR]