UMMS Affiliation

Department of Medicine, Division of Cardiovascular Medicine

Publication Date

2015-05-01

Document Type

Article

Disciplines

Cellular and Molecular Physiology | Digestive System Diseases | Lipids

Abstract

OXPHOS is believed to play an important role in non-alcoholic fatty liver disease (NAFLD), however, precise mechanisms whereby OXPHOS influences lipid homeostasis are incompletely understood. We previously reported that ectopic expression of LRPPRC, a protein that increases cristae density and OXPHOS, promoted fatty acid oxidation in cultured primary hepatocytes. To determine the biological significance of that observation and define underlying mechanisms, we have ectopically expressed LRPPRC in mouse liver in the setting of NAFLD. Interestingly, ectopic expression of LRPPRC in mouse liver completely interdicted NAFLD, including inflammation. Consistent with mitigation of NAFLD, two markers of hepatic insulin resistance-ROS and PKCepsilon activity-were both modestly reduced. As reported by others, improvement of NAFLD was associated with improved whole-body insulin sensitivity. Regarding hepatic lipid homeostasis, the ratio of NAD+ to NADH was dramatically increased in mouse liver replete with LRPPRC. Pharmacological activators and inhibitors of the cellular respiration respectively increased and decreased the [NAD+]/[NADH] ratio, indicating respiration-mediated control of the [NAD+]/[NADH] ratio. Supporting a prominent role for NAD+, increasing the concentration of NAD+ stimulated complete oxidation of fatty acids. Importantly, NAD+ rescued impaired fatty acid oxidation in hepatocytes deficient for either OXPHOS or SIRT3. These data are consistent with a model whereby augmented hepatic OXPHOS increases NAD+, which in turn promotes complete oxidation of fatty acids and protects against NAFLD.

Rights and Permissions

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

DOI of Published Version

10.1371/journal.pone.0125617

Source

PLoS One. 2015 May 1;10(5):e0125617. doi: 10.1371/journal.pone.0125617. eCollection 2015.. Link to article on publisher's site

Journal/Book/Conference Title

PloS one

Related Resources

Link to Article in PubMed

PubMed ID

25933096

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

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