Cardiac mitochondrial proteome of lean, healthy Ossabaw minipigs with predisposition to metabolic syndrome versus that of Göttingen minipigs

Ossabaw minipigs differ from other (mini)pig strains by their genetic predisposition to develop full metabolic syndrome and their nonresponsiveness to cardioprotective interventions, even before developing the diseased phenotype. Previous DNA sequencing data revealed differences in a cluster of mitochondrial protein-coding genes between Ossabaw and Göttingen minipigs-a large animal model without such a genetic predisposition and a responsiveness to cardioprotection. Alterations in mitochondrial protein composition affect mitochondrial function, and mitochondria play a crucial role in the development of metabolic syndrome and for cardioprotection. Therefore, we aimed to compare the cardiac mitochondrial proteome between lean Ossabaw minipigs with a healthy phenotype and Göttingen minipigs to gain initial insights into potential differences in mitochondrial protein composition and function. Cardiac mitochondria (left ventricular tissue) of both minipig strains (male/female pigs) were isolated, and the proteome was analyzed by liquid chromatography-tandem mass spectrometry. An unbiased, nonhypothesis-driven proteome analysis identified 97% overlap in the proteome. Among the 3% of differentially expressed proteins, 19 were related to mitochondrial metabolism, 8 to transcription and translation, 3 to small molecule transport, 2 to oxidative phosphorylation, and 1 to dynamics and surveillance. These small differences in protein composition were associated with an altered mitochondrial energy turnover-ATP production was reduced by 49% in Ossabaw compared with Göttingen minipig mitochondria. This proteome analysis provides a broader basis to understand how genetic alterations result in changes of the mitochondrial proteome and function, which might be relevant for the development and progression of metabolic syndrome and/or the primordial nonresponsiveness to cardioprotection in Ossabaw minipigs.<b>NEW & NOTEWORTHY</b> Our comprehensive cardiac mitochondrial proteome of Ossabaw and Göttingen minipigs is a valuable resource for cardiac biomedical research. Moreover, our proteome analysis provides a broader basis for understanding how genetic alterations result in changes of the mitochondrial proteome and support a mechanistic link between subtle, strain-specific mitochondrial proteomic signatures and altered mitochondrial energy turnover. These changes may be relevant for the development and progression of metabolic syndrome and/or primordial nonresponsiveness to cardioprotection in Ossabaw minipigs.