Referenced in: none

Automatically associated channels: TRP , TRPC , TRPC1 , TRPC3 , TRPC4

Title: Transient receptor potential channels contribute to pathological structural and functional remodeling after myocardial infarction.

Authors: Catherine A Makarewich, Hongyu Zhang, Jennifer Davis, Robert N Correll, Danielle M Trappanese, Nicholas E Hoffman, Constantine D Troupes, Remus M Berretta, Hajime Kubo, Muniswamy Madesh, Xiongwen Chen, Erhe Gao, Jeffery D Molkentin, Steven R Houser

Journal, date & volume: Circ. Res., 2014 Aug 29 , 115, 567-80

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/25047165

Abstract
The cellular and molecular basis for post-myocardial infarction (MI) structural and functional remodeling is not well understood.Our aim was to determine if Ca2+ influx through transient receptor potential canonical (TRPC) channels contributes to post-MI structural and functional remodeling.TRPC1/3/4/6 channel mRNA increased after MI in mice and was associated with TRPC-mediated Ca2+ entry. Cardiac myocyte-specific expression of a dominant-negative (loss-of-function) TRPC4 channel increased basal myocyte contractility and reduced hypertrophy and cardiac structural and functional remodeling after MI while increasing survival in mice. We used adenovirus-mediated expression of TRPC3/4/6 channels in cultured adult feline myocytes to define mechanistic aspects of these TRPC-related effects. TRPC3/4/6 overexpression in adult feline myocytes induced calcineurin (Cn)-nuclear factor of activated T-cells (NFAT)-mediated hypertrophic signaling, which was reliant on caveolae targeting of TRPCs. TRPC3/4/6 expression in adult feline myocytes increased rested state contractions and increased spontaneous sarcoplasmic reticulum Ca2+ sparks mediated by enhanced phosphorylation of the ryanodine receptor. TRPC3/4/6 expression was associated with reduced contractility and response to catecholamines during steady-state pacing, likely because of enhanced sarcoplasmic reticulum Ca2+ leak.Ca2+ influx through TRPC channels expressed after MI activates pathological cardiac hypertrophy and reduces contractility reserve. Blocking post-MI TRPC activity improved post-MI cardiac structure and function.