Plasma membrane Ca2+-ATPase isoform 4 antagonizes cardiac hypertrophy in association with calcineurin inhibition in rodents
Xu Wu, … , Gary E. Shull, Jeffery D. Molkentin
Xu Wu, … , Gary E. Shull, Jeffery D. Molkentin
Published April 1, 2009; First published March 16, 2009
Citation Information: J Clin Invest. 2009;119(4):976-985. https://doi.org/10.1172/JCI36693.
View: Text | PDF
Research Article Cardiology

Plasma membrane Ca2+-ATPase isoform 4 antagonizes cardiac hypertrophy in association with calcineurin inhibition in rodents

Abstract

How Ca2+-dependent signaling effectors are regulated in cardiomyocytes, given the extreme cytoplasmic Ca2+ concentration changes that underlie contraction, remains unknown. Cardiomyocyte plasma membrane Ca2+-ATPase (PMCA) extrudes Ca2+ but has little effect on excitation-contraction coupling, suggesting its potential role in controlling Ca2+-dependent signaling effectors such as calcineurin. We generated cardiac-specific inducible PMCA4b transgenic mice that displayed normal global Ca2+ transient and cellular contraction levels and reduced cardiac hypertrophy following transverse aortic constriction (TAC) or phenylephrine/Ang II infusion, but showed no reduction in exercise-induced hypertrophy. Transgenic mice were protected from decompensation and fibrosis following long-term TAC. The PMCA4b transgene reduced the hypertrophic augmentation associated with transient receptor potential canonical 3 channel overexpression, but not that associated with activated calcineurin. Furthermore, Pmca4 gene–targeted mice showed increased cardiac hypertrophy and heart failure events after TAC. Physical associations between PMCA4b and calcineurin were enhanced by TAC and by agonist stimulation of cultured neonatal cardiomyocytes. PMCA4b reduced calcineurin nuclear factor of activated T cell–luciferase activity after TAC and in cultured neonatal cardiomyocytes after agonist stimulation. PMCA4b overexpression inhibited cultured cardiomyocyte hypertrophy following agonist stimulation, but much less so in a Ca2+ pumping–deficient PMCA4b mutant. Thus, Pmca4b likely reduces the local Ca2+ signals involved in reactive cardiomyocyte hypertrophy via calcineurin regulation.

Authors

Xu Wu, Baojun Chang, N. Scott Blair, Michelle Sargent, Allen J. York, Jeffrey Robbins, Gary E. Shull, Jeffery D. Molkentin

×

Figure 8

PMCA4b overexpression blunts agonist-induced hypertrophy in cultured neonatal cardiomyocytes.

Options: View larger image (or click on image) Download as PowerPoint
PMCA4b overexpression blunts agonist-induced hypertrophy in cultured neo...
(A) Cardiomyocyte surface area by immunocytochemistry staining of α-actinin in control (Ad–β-gal) or Ad-PMCA4b–overexpressing conditions (*P < 0.05 versus no stimulation, #P < 0.05 versus Ad–β-gal + ET-1 or PE). (B) Relative [3H]-leucine incorporation in cultured neonatal cardiomyocytes infected with the indicated adenoviruses and co-stimulants (*P < 0.05 versus no stimulation, #P < 0.05 versus Ad–β-gal + PE). (C) DNA amplification from RT-PCR reactions for Anf mRNA, and subsequent quantitation (D) in control (Ad–β-gal) and Ad-PMCA4b–overexpressing cultured cardiomyocytes at baseline or after PE treatment (*P < 0.05 versus no stimulation, #P < 0.05 versus Ad–β-gal + PE). (E) Western blot for PMCA4b from adenoviral-infected neonatal cardiomyocytes expressing the indicated proteins. GAPDH was used as a protein loading control. (F) Fold increase in NFAT-luciferase activity from neonatal cardiomyocytes infected with Ad–NFAT-luciferase and Ad–β-gal, Ad–PMCA4b D672E, or Ad-PMCA4b (*P < 0.05 versus control, #P < 0.05 versus PMCA4b + PE). (G) Relative [3H]-leucine incorporation in cultured neonatal cardiomyocytes infected with the indicated adenoviruses and co-stimulants (*P < 0.05 versus control, #P < 0.05 versus PMCA4b + PE). Data were summed from 4–8 independent experiments.