Phosphodiesterase 5 inhibition blocks pressure overload-induced cardiac hypertrophy independent of the calcineurin pathway

Steven Hsu, Takahiro Nagayama, Norimichi Koitabashi, Manling Zhang, Liye Zhou, Djahida Bedja, Kathleen L. Gabrielson, Jeffery D. Molkentin, David A. Kass, Eiki Takimoto*

*Corresponding author for this work

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

Aims: Cyclic GMP (cGMP)-specific phosphodiesterase 5 (PDE5) inhibition by sildenafil (SIL) activates myocardial cGMP-dependent protein kinase G (PKG) and blunts cardiac hypertrophy. To date, the only documented target of PKG in myocardium is the serine-threonine phosphatase calcineurin (Cn), which is central to pathological cardiac hypertrophy. We tested whether Cn suppression is necessary in order to observe anti-hypertrophic effects of SIL. Methods and results: Mice lacking the Cn-Aβ subunit (CnAβ-/-) and wild-type (WT) controls were subjected to transverse aorta constriction (TAC) with or without SIL (200 mg/kg/day, p.o.) for 3 weeks. TAC-induced elevation of Cn expression and activity in WT was absent in CnAβ-/- hearts, and the latter accordingly developed less cardiac hypertrophy (50 vs. 100% increase in heart weight/tibia length, P < 0.03) and chamber dilation. SIL remained effective in CnAβ-/- mice, increasing PKG activity similarly as in WT, suppressing hypertrophy and fetal gene expression, and enhancing heart function without altering afterload. TAC-stimulated calcium-calmodulin kinase II, Akt, and glycogen synthase kinase 3β in both groups (the first rising more in CnAβ-/- hearts), and SIL also suppressed these similarly. Activation of extracellular signal-regulated kinase observed in WT-TAC but not CnAβ-/- hearts was also suppressed by SIL. Conclusion: PDE5A inhibition and its accompanying PKG activation blunt hypertrophy and improve heart function even without Cn activation. This occurs by its modulation of several alternative pathways which may result from concomitant distal targeting, or activity against a common proximal node.

Original languageEnglish
Pages (from-to)301-309
Number of pages9
JournalCardiovascular Research
Volume81
Issue number2
DOIs
Publication statusPublished - Feb 2009
Externally publishedYes

Fingerprint Dive into the research topics of 'Phosphodiesterase 5 inhibition blocks pressure overload-induced cardiac hypertrophy independent of the calcineurin pathway'. Together they form a unique fingerprint.

  • Cite this