Age-related insulin resistance in hypothalamus and peripheral tissues of orexin knockout mice

H. Tsuneki, S. Murata, Y. Anzawa, Y. Soeda, E. Tokai, T. Wada, I. Kimura, M. Yanagisawa, T. Sakurai, T. Sasaoka

Research output: Contribution to journalArticle

82 Citations (Scopus)

Abstract

Aims/hypothesis: Orexin/hypocretin is a hypothalamic neuropeptide that regulates motivated behaviours, such as feeding and arousal, and, importantly, is also involved in energy homeostasis. The aim of this study was to reveal the role of orexin in the regulation of insulin sensitivity for glucose metabolism. Methods: Orexin knockout mice fasted overnight underwent oral glucose tolerance testing and insulin tolerance testing. The impact of orexin deficiency on insulin signalling was studied by Western blotting to measure levels of Akt phosphorylation and its upstream and downstream molecules in the hypothalamus, muscle and liver in orexin knockout mice. Results: We found that orexin deficiency caused the age-related development of impaired glucose tolerance and insulin resistance in both male mice without obesity and female mice with mild obesity, fed a normal chow diet. When maintained on a high-fat diet, these abnormalities became more pronounced exclusively in female orexin knockout mice that developed severe obesity. Insulin signalling through Akt was disrupted in peripheral tissues of middle-aged (9-month-old) but not young adult (2-to-3-month-old) orexin knockout mice fed a normal chow diet. Moreover, basal levels of hypothalamic Akt phosphorylation were abnormally elevated in orexin knockout mice at every age studied, and insulin stimulation failed to increase the level of phosphorylation. Similar abnormalities were observed with respect to GSK3β phosphorylation in the hypothalamus and peripheral tissues of middle-aged orexin knockout mice. Conclusions/interpretation: Our results demonstrate a novel role for orexin in hypothalamic insulin signalling, which is likely to be responsible for preventing the development of peripheral insulin resistance with age.

Original languageEnglish (US)
Pages (from-to)657-667
Number of pages11
JournalDiabetologia
Volume51
Issue number4
DOIs
StatePublished - Apr 2008

Fingerprint

Knockout Mice
Hypothalamus
Insulin Resistance
Insulin
Phosphorylation
Obesity
Diet
Glucose Intolerance
Morbid Obesity
High Fat Diet
Glucose Tolerance Test
Arousal
Neuropeptides
Vascular Resistance
Young Adult
Homeostasis
Western Blotting
Glucose
Muscles
Liver

Keywords

  • Hypocretin
  • Hypothalamus
  • Impaired glucose tolerance
  • Insulin resistance
  • Insulin signalling
  • Orexin

ASJC Scopus subject areas

  • Internal Medicine
  • Endocrinology, Diabetes and Metabolism

Cite this

Tsuneki, H., Murata, S., Anzawa, Y., Soeda, Y., Tokai, E., Wada, T., ... Sasaoka, T. (2008). Age-related insulin resistance in hypothalamus and peripheral tissues of orexin knockout mice. Diabetologia, 51(4), 657-667. https://doi.org/10.1007/s00125-008-0929-8

Age-related insulin resistance in hypothalamus and peripheral tissues of orexin knockout mice. / Tsuneki, H.; Murata, S.; Anzawa, Y.; Soeda, Y.; Tokai, E.; Wada, T.; Kimura, I.; Yanagisawa, M.; Sakurai, T.; Sasaoka, T.

In: Diabetologia, Vol. 51, No. 4, 04.2008, p. 657-667.

Research output: Contribution to journalArticle

Tsuneki, H, Murata, S, Anzawa, Y, Soeda, Y, Tokai, E, Wada, T, Kimura, I, Yanagisawa, M, Sakurai, T & Sasaoka, T 2008, 'Age-related insulin resistance in hypothalamus and peripheral tissues of orexin knockout mice', Diabetologia, vol. 51, no. 4, pp. 657-667. https://doi.org/10.1007/s00125-008-0929-8
Tsuneki, H. ; Murata, S. ; Anzawa, Y. ; Soeda, Y. ; Tokai, E. ; Wada, T. ; Kimura, I. ; Yanagisawa, M. ; Sakurai, T. ; Sasaoka, T. / Age-related insulin resistance in hypothalamus and peripheral tissues of orexin knockout mice. In: Diabetologia. 2008 ; Vol. 51, No. 4. pp. 657-667.
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AU - Murata, S.

AU - Anzawa, Y.

AU - Soeda, Y.

AU - Tokai, E.

AU - Wada, T.

AU - Kimura, I.

AU - Yanagisawa, M.

AU - Sakurai, T.

AU - Sasaoka, T.

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