Acute starvation in C57BL/6J mice increases myocardial UCP2 and UCP3 protein expression levels and decreases mitochondrial bio-energetic function

Abstract

Associations between uncoupling protein (UCP) expression and functional changes in myocardial mitochondrial bio-energetics have not been well studied during periods of starvation stress. Our aim was to study the effects of acute starvation, for 24 or 48 h, on combined cardiac mitochondrial function and UCP expression in mice. Isolated heart mitochondria from female mice starved for 48 h compared to that from mice fed revealed a significantly (p < 0.05) decreased adenosine diphosphate-to-oxygen ratio, a significantly increased proton leak and an increased GTP inhibition on palmitic acid-induced state 4 oxygen consumption (p < 0.05). These bio-energetic functional changes were associated with increases in mitochondrial UCP2 and UCP3 protein expression. In conclusion, our findings suggest that increased UCP2 and UCP3 levels may contribute to decreased myocardial mitochondrial bio-energetic function due to starvation.

Dietary soya protein improves intra-myocardial lipid deposition and altered glucose metabolism in a hypertensive, dyslipidaemic, insulin-resistant rat model

“…Li et al ( 31 ) demonstrated that increased FA induced UCP2 expression through PPAR α activation in the adult rat cardiomyocytes. An increase of myocardial UCP2 and UCP3 protein expression levels and a decrease of mitochondrial bio-energetic function were also recorded in the heart of C57BL/6 J mice with acute starvation ( 32 ) . The heart of lean Zucker rats showed a significant increase of UCP2 and UCP3 gene expression during lipid infusion under an euglycaemic–hyperinsulinaemic clamp ( 33 ) .…”

Potential Role of Plasmalogens in the Modulation of Biomembrane Morphology

“…Furthermore, it has been suggested that cubic membranes which harbor a significant amount of plasmalogens (Deng et al, 2009), might act as a "defensive" shield to mitigate the oxidation of biologically vital macromolecules (e.g., lipids, oligonucleotides, and mRNAs; Almsherqi et al, 2008;Deng and Almsherqi, 2015;Deng et al, 2017). In this light, further studies carried out on amoeba Chaos showed that when oxidation was imminent in the mitochondria (Wang et al, 2011;Rambold et al, 2015) during cell starvation, the percentage of cell survival in amoeba Chaos with cubic membrane (rich in plasmalogens) was significantly higher than those amoeba without mitochondrial cubic membrane transformation (Chong et al, 2018). This suggested that plasmalogens play a role not only in membrane transformation but also as a cytoprotectant to promote cell survival.…”

Shortened leukocyte telomere length in type 2 diabetes mellitus: genetic polymorphisms in mitochondrial uncoupling proteins and telomeric pathways

“…The −866G < A UCP2 variant was also particularly related to shorter LTL in patients [13]. These studies were some of the first to suggest a possible association between the efficiency of mitochondrial UCP regulation of reactive oxygen species [44,45] and shorter telomere length in T2DM.…”