Disruption of the histidine triad nucleotide-binding hint2 gene in mice affects glycemic control and mitochondrial function

Martin, Juliette; Maurhofer, Olivier; Bellance, Nadège; Benard, Giovanni; Graber, Franziska; Hahn, Dagmar Karen; Galinier, Anne; Hora, Caroline; Gupta, Anirudh; Ferrand, Gisèle; Hoppeler, Hans; Rossignol, Rodrigue; Dufour, Jean-François; St-Pierre, Marie V (2012). Disruption of the histidine triad nucleotide-binding hint2 gene in mice affects glycemic control and mitochondrial function. Hepatology, 57(5), pp. 2037-2048. Hoboken, N.J.: Wiley Interscience 10.1002/hep.26060

Full text not available from this repository.

The histidine triad nucleotide-binding (Hint2) protein is a mitochondrial adenosine phosphoramidase expressed in liver and pancreas. Its physiological function is unknown. To elucidate the role of Hint2 in liver physiology, the Hint2 gene was deleted. Hint2(-/-) and Hint2(+/+) mice were generated in a mixed C57Bl6/J x 129Sv background. At 20 weeks, the phenotypic changes in Hint2(-/-) relative to Hint2(+/+) mice were an accumulation of hepatic triglycerides, decreased tolerance to glucose, a defective counter-regulatory response to insulin-provoked hypoglycaemia, an increase in plasma interprandial insulin but a decrease in glucose stimulated insulin secretion and defective thermoregulation upon fasting. Leptin mRNA in adipose tissue and plasma leptin were elevated. In mitochondria from Hint2(-/-) hepatocytes, state 3 respiration was decreased, a finding confirmed in HepG2 cells where HINT2 mRNA was silenced. The linked complex II to III electron transfer was decreased in Hint2(-/-) mitochondria, which was accompanied by a lower content of coenzyme Q. HIF-2α expression and the generation of reactive oxygen species were increased. Electron microscopy of mitochondria in Hint2(-/-) mice aged 12 months revealed clustered, fused organelles. The hepatic activities of 3-hydroxyacyl-CoA dehydrogenase short chain and glutamate dehydrogenase (GDH) were decreased by 68% and 60%, respectively, without a change in protein expression. GDH activity was similarly decreased in HINT2-silenced HepG2 cells. When measured in the presence of purified sirtuin 3, latent GDH activity was recovered (126% in Hint2(-/-) vs. 83% in Hint2(+/+) ). This suggests a greater extent of acetylation in Hint2(-/-) than in Hint2(+/+) . Conlusions: Hint2 positively regulates mitochondrial lipid metabolism and respiration, and glucose homeostasis. The absence of Hint2 provokes mitochondrial deformities and a change in the pattern of acetylation of selected proteins. (HEPATOLOGY 2012.).

Item Type:	Journal Article (Original Article)
Division/Institute:	04 Faculty of Medicine > Department of Haematology, Oncology, Infectious Diseases, Laboratory Medicine and Hospital Pharmacy (DOLS) > Institute of Clinical Chemistry 04 Faculty of Medicine > Pre-clinic Human Medicine > Institute of Anatomy 04 Faculty of Medicine > Department of Gastro-intestinal, Liver and Lung Disorders (DMLL) > Clinic of Visceral Surgery and Medicine > Hepatology
UniBE Contributor:	Hahn, Dagmar Karen, Hoppeler, Hans-Heinrich, Dufour, Jean-François
Subjects:	600 Technology > 610 Medicine & health
ISSN:	0270-9139
Publisher:	Wiley Interscience
Language:	English
Submitter:	Annette Draeger
Date Deposited:	04 Oct 2013 14:35
Last Modified:	05 Dec 2022 14:11
Publisher DOI:	10.1002/hep.26060
PubMed ID:	22961760
Web of Science ID:	000318162200038
URI:	https://boris.unibe.ch/id/eprint/14060 (FactScience: 220863)