| First Author | Beca S | Year | 2013 |
| Journal | Circ Res | Volume | 112 |
| Issue | 2 | Pages | 289-97 |
| PubMed ID | 23168336 | Mgi Jnum | J:212868 |
| Mgi Id | MGI:5582369 | Doi | 10.1161/CIRCRESAHA.111.300003 |
| Citation | Beca S, et al. (2013) Phosphodiesterase type 3A regulates basal myocardial contractility through interacting with sarcoplasmic reticulum calcium ATPase type 2a signaling complexes in mouse heart. Circ Res 112(2):289-97 |
| abstractText | RATIONALE: cAMP is an important regulator of myocardial function, and regulation of cAMP hydrolysis by cyclic nucleotide phosphodiesterases (PDEs) is a critical determinant of the amplitude, duration, and compartmentation of cAMP-mediated signaling. The role of different PDE isozymes, particularly PDE3A vs PDE3B, in the regulation of heart function remains unclear. OBJECTIVE: To determine the relative contribution of PDE3A vs PDE3B isozymes in the regulation of heart function and to dissect the molecular basis for this regulation. METHODS AND RESULTS: Compared with wild-type littermates, cardiac contractility and relaxation were enhanced in isolated hearts from PDE3A(-/-), but not PDE3B(-/-), mice. Furthermore, PDE3 inhibition had no effect on PDE3A(-/-) hearts but increased contractility in wild-type (as expected) and PDE3B(-/-) hearts to levels indistinguishable from PDE3A(-/-). The enhanced contractility in PDE3A(-/-) hearts was associated with cAMP-dependent elevations in Ca(2+) transient amplitudes and increased sarcoplasmic reticulum (SR) Ca(2+) content, without changes in L-type Ca(2+) currents of cardiomyocytes, as well as with increased SR Ca(2+)-ATPase type 2a activity, SR Ca(2+) uptake rates, and phospholamban phosphorylation in SR fractions. Consistent with these observations, PDE3 activity was reduced approximately 8-fold in SR fractions from PDE3A(-/-) hearts. Coimmunoprecipitation experiments further revealed that PDE3A associates with both SR calcium ATPase type 2a and phospholamban in a complex that also contains A-kinase anchoring protein-18, protein kinase type A-RII, and protein phosphatase type 2A. CONCLUSIONS: Our data support the conclusion that PDE3A is the primary PDE3 isozyme modulating basal contractility and SR Ca(2+) content by regulating cAMP in microdomains containing macromolecular complexes of SR calcium ATPase type 2a-phospholamban-PDE3A. |
