title: Proteomic analysis of liver mitochondria of apolipoprotein E knockout mice treated with metformin.
abstract: Nonalcoholic fatty liver disease (NAFLD) is strongly associated with insulin resistance. Metformin, a widely known anti-diabetic drug, used for patients with type 2 diabetes mellitus, is also claimed to be useful in treatment of NAFLD. However, both the clinical efficacy and the putative mechanisms underlying the clinical effects of metformin in treating NAFLD are unclear. Adenosine monophosphate-activated protein kinase (AMPK), the primary molecular target for metformin, is a known regulator of mitochondrial function. Thus, we used a proteomic approach to investigate the effect of metformin on liver mitochondria of apolipoprotein E knockout (apoE(-/-)) mice, an animal model of NAFLD. Two-dimensional electrophoresis coupled with mass spectrometry was applied to study the changes in liver mitochondrial protein expression in 6-month old metformin-treated apoE(-/-) mice as compared to non-treated animals. Collectively, 25 differentially expressed proteins were indentified upon metformin treatment including proteins related to metabolism, oxidative stress and cellular respiration. The most up-regulated protein was glycine N-methyltransferase (GNMT) - an enzyme, whose deficiency was shown to be directly related to the development of NAFLD. Our results clearly point to the strong mitochondrial action of metformin in NAFLD. Up-regulation of GNMT may represent an important mechanism of beneficial action of metformin in NAFLD treatment.
authors.affiliation: Chair of Pharmacology, Jagiellonian University Medical College, Poland.
authors.forename: Aneta
authors.initials: A
authors.lastname: Stachowicz
authors.forename: Maciej
authors.initials: M
authors.lastname: Suski
authors.forename: Rafał
authors.initials: R
authors.lastname: Olszanecki
authors.forename: Józef
authors.initials: J
authors.lastname: Madej
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Okoń
authors.forename: Ryszard
authors.initials: R
authors.lastname: Korbut
mesh_terms: D000818:Animals; D001057:Apolipoproteins E; D004195:Disease Models, Animal; D005234:Fatty Liver / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D008687:Metformin / Q000494:pharmacology*; D051379:Mice; D018345:Mice, Knockout; D008930:Mitochondria, Liver / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D024101:Mitochondrial Proteins / Q000096:biosynthesis* / Q000235:genetics; D065626:Non-alcoholic Fatty Liver Disease; D020543:Proteome / Q000096:biosynthesis* / Q000235:genetics; D040901:Proteomics / Q000379:methods; D015854:Up-Regulation / Q000187:drug effects*
chemical_list: D001057:Apolipoproteins E; D007004:Hypoglycemic Agents; D024101:Mitochondrial Proteins; D020543:Proteome; D008687:Metformin