Heat shock protein-27 delays acute rejection after cardiac transplantation: an experimental model.

Background: Rejection is the major obstacle to survival after cardiac transplantation. We investigated whether overexpression of heat shock protein (Hsp)-27 in mouse hearts protects against acute rejection and the mechanisms of such protection.

Methods: Hearts from B10.

Increased cardiogenesis in P19-GFP teratocarcinoma cells expressing the propeptide IGF-1Ea.

The mechanism implicated in differentiation of endogenous cardiac stem cells into cardiomyocytes to regenerate the heart tissue upon an insult remains elusive, limiting the therapeutical goals to exogenous cell injection and/or gene therapy. We have shown previously that cardiac specific overexpression of the insulin-like growth factor 1 propeptide IGF-1Ea induces beneficial myocardial repair after infarct. Although the mechanism is still under investigation, the possibility that this propeptide may be involved in promoting stem cell differentiation into the cardiac lineage has yet to be explored.

Calcineurin splicing variant calcineurin Aβ1 improves cardiac function after myocardial infarction without inducing hypertrophy.

Background: Calcineurin is a calcium-regulated phosphatase that plays a major role in cardiac hypertrophy. We previously described that alternative splicing of the calcineurin Aβ (CnAβ) gene generates the CnAβ1 isoform, with a unique C-terminal region that is different from the autoinhibitory domain present in all other CnA isoforms. In skeletal muscle, CnAβ1 is necessary for myoblast proliferation and stimulates regeneration, reducing fibrosis and accelerating the resolution of inflammation.

Cross-regulation between beta 1- and beta 3-adrenoceptors following chronic beta-adrenergic stimulation in neonatal rat cardiomyocytes.

Background And Purpose: We have previously shown that beta-adrenoceptors continuously stimulated with noradrenaline induces an increase in beta(3)-adrenoceptors (G alpha(i)PCRs) and a decrease in beta(1)-adrenoceptors (G alpha(s)PCRs) at functional, genomic and protein levels. This compensatory modification induced by noradrenaline is probably one of the consequences of cardiac depression observed in heart disease. Therefore, we investigated further the interaction between beta(1)- and beta(3)-adrenoceptors in neonatal rat cardiomyocytes.

Characterization of P2Y receptor subtypes functionally expressed on neonatal rat cardiac myofibroblasts.

Background And Purpose: Little is known about P2Y receptors in cardiac fibroblasts, which represent the predominant cell type in the heart and differentiate into myofibroblasts under certain conditions. Therefore, we have characterized the phenotype of the cells and the different P2Y receptors at the expression and functional levels in neonatal rat non-cardiomyocytes.

Experimental Approach: Non-cardiomyocyte phenotype was determined by confocal microscopy by using discoidin domain receptor 2, alpha-actin and desmin antibodies.