Expression, activity, and pro-hypertrophic effects of PDE5A in cardiac myocytes

Manling Zhang, Norimichi Koitabashi, Takahiro Nagayama, Ryan Rambaran, Ning Feng, Eiki Takimoto, Trisha Koenke, Brian O'Rourke, Hunter C. Champion, Michael T. Crow, David A. Kass

Research output: Contribution to journalArticlepeer-review

68 Scopus citations

Abstract

Cyclic GMP-selective phosphodiesterase type 5 (PDE5) has been traditionally thought to play a little role in cardiac myocytes, yet recent studies using selective inhibitors such as sildenafil suggest it can potently modulate acute and chronic cardiac stress responses. To date, evidence for myocyte PDE5 expression and regulation has relied on small-molecule inhibitors and anti-sera, leaving open concerns regarding non-specific immune-reactivity, and off-target drug effects. To directly address both issues, we engineered a robust PDE5-gene silencing shRNA (inserted into miRNA-155 cassette) and DsRed-PDE5 fusion protein, both coupled to a CMV promoter and incorporated into adenoviral vectors. PDE5 mRNA and protein knock-down eliminated anti-sera positivity on immunoblots and fluorescent immuno-histochemistry in neonatal and adult cardiomyocytes, and suppressed PDE5 enzyme activity. Stimulation of myocyte hypertrophy by phenylephrine was blunted by PDE5 gene silencing in a protein kinase G dependent manner, and this effect was similar to that from sildenafil with no additive response by both combined. DsRed-PDE5 fusion protein expression showed normal z-band localization in adult myocytes but was diffused in eNOS-/- myocytes; echoing reported findings with anti-sera. PDE5 overexpression increased enzyme activity and amplified natriuretic peptide gene expression from phenylephrine stimulation. These data confirm PDE5 expression, activity, and targeted inhibition by sildenafil in cardiomyocytes, as well as the role of this PDE in cardiomyocyte hypertrophy modulation.

Original languageEnglish (US)
Pages (from-to)2231-2236
Number of pages6
JournalCellular Signalling
Volume20
Issue number12
DOIs
StatePublished - Dec 2008

Keywords

  • Phosphodiesterase 5A
  • Protein kinase G
  • Sildenafil

ASJC Scopus subject areas

  • Cell Biology

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