The mitochondrial ATP synthase is a negative regulator of the mitochondrial permeability transition pore.

The mitochondrial permeability transition pore (mPTP) is a channel in the inner mitochondrial membrane whose sustained opening in response to elevated mitochondrial matrix Ca concentrations triggers necrotic cell death. The molecular identity of mPTP is unknown. One proposed candidate is the mitochondrial ATP synthase, whose canonical function is to generate most ATP in multicellular organisms.

Tissue transglutaminase induction in the pressure-overloaded myocardium regulates matrix remodelling.

Aims: Tissue transglutaminase (tTG) is induced in injured and remodelling tissues, and modulates cellular phenotype, while contributing to matrix cross-linking. Our study tested the hypothesis that tTG may be expressed in the pressure-overloaded myocardium, and may regulate cardiac function, myocardial fibrosis and chamber remodelling.

Methods And Results: In order to test the hypothesis, wild-type and tTG null mice were subjected to pressure overload induced through transverse aortic constriction.