Altered glucose metabolism and hypoxic response in alloxan-induced diabetic atherosclerosis in rabbits

PLoS One. 2017 Apr 14;12(4):e0175976. doi: 10.1371/journal.pone.0175976. eCollection 2017.

Abstract

Diabetes mellitus accelerates atherosclerosis that causes most cardiovascular events. Several metabolic pathways are considered to contribute to the development of atherosclerosis, but comprehensive metabolic alterations to atherosclerotic arterial cells remain unknown. The present study investigated metabolic changes and their relationship to vascular histopathological changes in the atherosclerotic arteries of rabbits with alloxan-induced diabetes. Diabetic atherosclerosis was induced in rabbit ilio-femoral arteries by injecting alloxan (100 mg/kg), injuring the arteries using a balloon, and feeding with a 0.5% cholesterol diet. We histologically assessed the atherosclerotic lesion development, cellular content, pimonidazole positive-hypoxic area, the nuclear localization of hypoxia-inducible factor-1α, and apoptosis. We evaluated comprehensive arterial metabolism by performing metabolomic analyses using capillary electrophoresis-time of flight mass spectrometry. We evaluated glucose uptake and its relationship to vascular hypoxia using 18F-fluorodeoxyglucose and pimonidazole. Plaque burden, macrophage content, and hypoxic areas were more prevalent in arteries with diabetic, than non-diabetic atherosclerosis. Metabolomic analyses highlighted 12 metabolites that were significantly altered between diabetic and non-diabetic atherosclerosis. A half of them were associated with glycolysis metabolites, and their levels were decreased in diabetic atherosclerosis. The uptake of glucose evaluated as 18F-fluorodeoxyglucose in atherosclerotic lesions increased according to increased macrophage content or hypoxic areas in non-diabetic, but not diabetic rabbits. Despite profound hypoxic areas, the nuclear localization of hypoxia-inducible factor-1α decreased and the number of apoptotic cells increased in diabetic atherosclerotic lesions. Altered glycolysis metabolism and an impaired response to hypoxia in atherosclerotic lesions under conditions of insulin-dependent diabetes might be involved in the development of diabetic atherosclerosis.

MeSH terms

  • Alloxan / toxicity*
  • Animals
  • Apoptosis
  • Atherosclerosis / diagnostic imaging
  • Atherosclerosis / etiology
  • Atherosclerosis / pathology*
  • Autoradiography
  • Body Weight
  • Cluster Analysis
  • Diabetes Mellitus, Experimental / chemically induced*
  • Diabetes Mellitus, Experimental / complications
  • Diet, High-Fat
  • Electrophoresis, Capillary
  • Femoral Artery / diagnostic imaging
  • Femoral Artery / pathology
  • Fluorodeoxyglucose F18 / chemistry
  • Fluorodeoxyglucose F18 / metabolism
  • Glucose / metabolism*
  • Glycolysis
  • Hypoxia*
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Immunohistochemistry
  • Macrophages / metabolism
  • Macrophages / pathology
  • Mass Spectrometry
  • Metabolomics
  • Microscopy, Fluorescence
  • Nitroimidazoles / chemistry
  • Nitroimidazoles / metabolism
  • Principal Component Analysis
  • Rabbits

Substances

  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Nitroimidazoles
  • Fluorodeoxyglucose F18
  • pimonidazole
  • Alloxan
  • Glucose

Grants and funding

This study was supported in part by Grants-in-Aid for Scientific Research in Japan (Nos. 25460440, 23390084, 16K08670, and 16H05163) from the Ministry of Education, Science, Sports and Culture of Japan, http://www.jsps.go.jp, Clinical Research from Miyazaki University Hospital, http://www.med.miyazaki-u.ac.jp/home/ Mitsui Life Welfare Foundation, http://www.kousei-zigyodan.or.jp/igakukenkyu_zyosei.html, SENSHIN Medical Research Foundation, https://www.smrf.or.jp, Intramural Research Fund (25-4-3) for Cardiovascular Diseases of the National Cerebral and Cardiovascular Center, http://www.ncvc.go.jp, and the Bayer Scholarship for Cardiovascular Research, http://www.jcvrf.jp/research/baieru.html.