However, the continuous presence of p57Kip2 in the adult mouse heart results in resistance to myocardial ischemia/reperfusion injury and improved recovery of cardiac function.
Inactivation of the Hippo pathway, which restrains cell proliferation and thus controls organ size in Drosophila, in the embryonic mouse heart results in development of enlarged hearts which display increased numbers of CMs and increased CM proliferation [ 75].
Conditional inactivation of Hccs in mouse heart results in severe defects of the MRC and in the accumulation of massively enlarged and aberrant mitochondria, with disorganized cristae, leading to mid-gestational lethality in hemizygous Hccs knockout (KO) males.
Another recent study found that injection of recombinant Wnt3a protein into infarcted mouse hearts resulted in an increase in infarct size and worsened cardiac performance, and it was suggested that this is due to a negative influence of Wnt3a on proliferation of cardiac side population (sca1+, c-kit−, isl−) progenitor cells [ 99].
Mutation of MED30 in the mouse heart results in lethal cardiomyopathy due to altered mitochondria [79].
Transgenic overexpression of CaMKIIδC in mouse hearts results in severe dilated cardiomyopathy.
Over-expression of Gαq in mice heart results in heart failure, this is accompanied by over expression of Nix/Bnip3L, a BH3 like protein, that can induce cardiomiocyte apoptosis [ 99].
Elevated protein levels of MED13 in the heart resulted in a significant increase in oxygen consumption, whereas the cardiac deletion of MED13 resulted in increased lipid accumulation without changes in food intake in mice (Grueter et al. 2012).
Injection of human CSCs into the infarcted rat/mouse heart resulted in a chimeric heart that was integrated into the myocardium of the rodent and contributed positively to the cardiac performance [ 77].
Significantly, the cytoplasmic LacZ-CUG RNA aggregates are unable to dysregulate splice site choice in mouse hearts and result only in mild cardiac dysfunction.
The exact mechanism of eNOS modification is unknown but in vivo experiments have shown that eNOS activation in aortas and iNOS transgenetic expression in mouse heart both result in NO-induced protein S-glutathionylation [45].
