8-Oxoguanine DNA Glycosylase (OGG1) Deficiency Increases Susceptibility to Obesity and Metabolic Dysfunction

Harini Sampath, Vladimir Vartanian, M. Rick Rollins, Kunihiko Sakumi, Yusaku Nakabeppu, R. Stephen Lloyd

Research output: Contribution to journalArticlepeer-review

101 Scopus citations

Abstract

Oxidative damage to DNA is mainly repaired via base excision repair, a pathway that is catalyzed by DNA glycosylases such as 8-oxoguanine DNA glycosylase (OGG1). While OGG1 has been implicated in maintaining genomic integrity and preventing tumorigenesis, we report a novel role for OGG1 in altering cellular and whole body energy homeostasis. OGG1-deficient (Ogg1-/-) mice have increased adiposity and hepatic steatosis following exposure to a high-fat diet (HFD), compared to wild-type (WT) animals. Ogg1-/- animals also have higher plasma insulin levels and impaired glucose tolerance upon HFD feeding, relative to WT counterparts. Analysis of energy expenditure revealed that HFD-fed Ogg1-/- mice have a higher resting VCO2 and consequently, an increased respiratory quotient during the resting phase, indicating a preference for carbohydrate metabolism over fat oxidation in these mice. Additionally, microarray and quantitative PCR analyses revealed that key genes of fatty acid oxidation, including carnitine palmitoyl transferase-1, and the integral transcriptional co-activator Pgc-1α were significantly downregulated in Ogg1-/- livers. Multiple genes involved in TCA cycle metabolism were also significantly reduced in livers of Ogg1-/- mice. Furthermore, hepatic glycogen stores were diminished, and fasting plasma ketones were significantly reduced in Ogg1-/- mice. Collectively, these data indicate that OGG1 deficiency alters cellular substrate metabolism, favoring a fat sparing phenotype, that results in increased susceptibility to obesity and related pathologies in Ogg1-/- mice.

Original languageEnglish (US)
Article numbere51697
JournalPloS one
Volume7
Issue number12
DOIs
StatePublished - Dec 17 2012

ASJC Scopus subject areas

  • General Biochemistry, Genetics and Molecular Biology
  • General Agricultural and Biological Sciences
  • General

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