Vitamin C modulates the levels of several proteins of the mitochondrial complex III and its activity in the mouse liver

Lucie Aumailley; Sylvie Bourassa; Clarisse Gotti; Arnaud Droit; Michel Lebel

doi:10.1016/j.redox.2022.102491

Vitamin C modulates the levels of several proteins of the mitochondrial complex III and its activity in the mouse liver

Redox Biol. 2022 Nov:57:102491. doi: 10.1016/j.redox.2022.102491. Epub 2022 Sep 24.

Authors

Lucie Aumailley¹, Sylvie Bourassa², Clarisse Gotti², Arnaud Droit³, Michel Lebel⁴

Affiliations

¹ Centre de recherche du CHU de Québec, Faculty of Medicine, Université Laval, Québec City, Québec, G1V 4G2, Canada.
² Proteomics Platform, Centre de recherche du CHU de Québec, Faculty of Medicine, Université Laval, Québec City, Québec, G1V 4G2, Canada.
³ Centre de recherche du CHU de Québec, Faculty of Medicine, Université Laval, Québec City, Québec, G1V 4G2, Canada; Proteomics Platform, Centre de recherche du CHU de Québec, Faculty of Medicine, Université Laval, Québec City, Québec, G1V 4G2, Canada.
⁴ Centre de recherche du CHU de Québec, Faculty of Medicine, Université Laval, Québec City, Québec, G1V 4G2, Canada. Electronic address: michel.lebel@crchudequebec.ulaval.ca.

Abstract

Ascorbate is a crucial antioxidant and essential cofactor of biosynthetic and regulatory enzymes. Unlike humans, mice can synthesize ascorbate thanks to the key enzyme gulonolactone oxidase (Gulo). In the present study, we used the Gulo^-/- mouse model, which cannot synthesize their own ascorbate to determine the impact of this vitamin on the liver proteome of specific subcellular organelles. We performed label-free Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) global quantitative proteomic profiling to identify and quantify proteins in microsomal enriched liver extracts (MEE) from Gulo^-/- mice treated with 0-0.4% (w/v) ascorbate in drinking water until the age of four months. Using a principal component analysis on normalized and imputed data of the label-free protein quantifications, a sex-based difference in MEE proteome profiles was observed for all the different ascorbate treated mice. Suboptimal hepatic ascorbate concentrations affected the levels of more proteins and hence biochemical processes in females than in males. Nevertheless, Pearson correlation analyses revealed that the MS intensities of various proteins involved in complement activation inversely correlated with liver ascorbate concentrations in both Gulo^-/- males and females. Moreover, the correlation analyses also indicated that several proteins in the mitochondrial complex III of the electron transport chain positively correlated with liver ascorbate concentrations in both Gulo^-/- females and males. Consequently, the mitochondrial complex III activity in Gulo^-/- female and male mice treated with suboptimal hepatic concentrations of ascorbate was significantly lower than Gulo^-/- mice treated with optimal ascorbate concentration. Finally, the whole liver of ascorbate-deficient Gulo^-/- mice exhibited lower ATP levels and increased reactive oxygen species. These findings provide new information on how ascorbate deficiency potentially induces mitochondrial dysfunction in the liver of mice.

Keywords: Gulonolactone oxidase; Liver; Mass spectrometry; Mitochondrial complex III; Mouse; Reactive oxygen species; Sex-related differences; Vitamin C.