Store-Operated Cyclic AMP Signaling (SOcAMPS) represents a novel signaling mechanism in which depletion of Ca2+ in the endoplasmic reticulum (ER) leads to a STIM1- dependent (Stromal Interaction Molecule 1) increase in cAMP levels, independently of cytosolic Ca2+. Here we aimed to evaluate whether SOcAMPS was manifest in neonatal rat ventricular myocytes (NRVM) and human "iCardiomyocytes" and exploit its potential role in cardiac cell hypertrophy. cAMP levels and ER [Ca2+]were monitored by live cell fluorescence imaging after transfection with the EPAC H30 and D1ER cameleon probes, respectively. The existence of SOcAMPS in NRVM was first assessed by using the low affinity Ca2+ chelator TPEN, able to induce a reduction of SR Ca2+ levels without affecting cytosolic [Ca2+]. TPEN (1mM) was shown to induce significant cAMP increases both in the absence and presence of 5 M Forskolin (FRSK). Depletion of SR by ionomycin (10 M) was found to exert similar effects. Similar data were obtained in human "iCardiomyocytes". The participation of STIM1 in the observed phenomenon was proven in NRVM by the 47% reduction of the [cAMP] response obtained after shRNA-mediated knockdown of STIM1. Interestingly, a significant increase of the TPEN+FRSK induced response was found after "in vitro" induced cell hypertrophy. These data establish, for the first time, the existence of SOcAMPS in the two cardiac cell models analyzed and suggest a potential role for this new signaling mechanism in cardiac cell hypertrophy.
The role of Store-Operated Cyclic AMP Signalling (SOcAMPS) in cardiac physiology and pathology
Gerbino A;DEBELLIS, Lucantonio;COLELLA, Matilde
2012-01-01
Abstract
Store-Operated Cyclic AMP Signaling (SOcAMPS) represents a novel signaling mechanism in which depletion of Ca2+ in the endoplasmic reticulum (ER) leads to a STIM1- dependent (Stromal Interaction Molecule 1) increase in cAMP levels, independently of cytosolic Ca2+. Here we aimed to evaluate whether SOcAMPS was manifest in neonatal rat ventricular myocytes (NRVM) and human "iCardiomyocytes" and exploit its potential role in cardiac cell hypertrophy. cAMP levels and ER [Ca2+]were monitored by live cell fluorescence imaging after transfection with the EPAC H30 and D1ER cameleon probes, respectively. The existence of SOcAMPS in NRVM was first assessed by using the low affinity Ca2+ chelator TPEN, able to induce a reduction of SR Ca2+ levels without affecting cytosolic [Ca2+]. TPEN (1mM) was shown to induce significant cAMP increases both in the absence and presence of 5 M Forskolin (FRSK). Depletion of SR by ionomycin (10 M) was found to exert similar effects. Similar data were obtained in human "iCardiomyocytes". The participation of STIM1 in the observed phenomenon was proven in NRVM by the 47% reduction of the [cAMP] response obtained after shRNA-mediated knockdown of STIM1. Interestingly, a significant increase of the TPEN+FRSK induced response was found after "in vitro" induced cell hypertrophy. These data establish, for the first time, the existence of SOcAMPS in the two cardiac cell models analyzed and suggest a potential role for this new signaling mechanism in cardiac cell hypertrophy.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
