Compensatory hyperinsulinemia in high-fat diet-induced obese mice is associated with enhanced insulin translation in islets

Journal Article · Fri Mar 13 04:00:00 EDT 2015 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2015.02.024· OSTI ID:22458531

Kanno, Ayumi ^[1]; Asahara, Shun-ichiro ^[1]; Masuda, Katsuhisa ^[2]; Matsuda, Tomokazu ^[1]; Kimura-Koyanagi, Maki ^[1]; Seino, Susumu ^[3]; Ogawa, Wataru ^[1]; Kido, Yoshiaki ^[1]

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1. Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe 650-0017 (Japan)
2. Division of Medical Chemistry, Department of Biophysics, Kobe University Graduate School of Health Sciences, Kobe 654-0142 (Japan)
3. Division of Molecular and Metabolic Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe 650-0047 (Japan)

A high-fat diet (HF) is associated with obesity, insulin resistance, and hyperglycemia. Animal studies have shown compensatory mechanisms in pancreatic β-cells after high fat load, such as increased pancreatic β-cell mass, enhanced insulin secretion, and exocytosis. However, the effects of high fat intake on insulin synthesis are obscure. Here, we investigated whether insulin synthesis was altered in correlation with an HF diet, for the purpose of obtaining further understanding of the compensatory mechanisms in pancreatic β-cells. Mice fed an HF diet are obese, insulin resistant, hyperinsulinemic, and glucose intolerant. In islets of mice fed an HF diet, more storage of insulin was identified. We analyzed insulin translation in mouse islets, as well as in INS-1 cells, using non-radioisotope chemicals. We found that insulin translational levels were significantly increased in islets of mice fed an HF diet to meet systemic demand, without altering its transcriptional levels. Our data showed that not only increased pancreatic β-cell mass and insulin secretion but also elevated insulin translation is the major compensatory mechanism of pancreatic β-cells. - Highlights: • More stored insulin was recognized in islets of mice fed a high-fat diet. • Insulin translation was not enhanced by fatty acids, but by insulin demand. • Insulin transcription was not altered in islets of mice fed a high-fat diet. • Insulin translation was markedly enhanced in islets of mice fed a high-fat diet. • Non-radioisotope chemicals were used to measure insulin translation in mouse islets.

• OSTI ID: 22458531
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 3 Vol. 458; ISSN 0006-291X; ISSN BBRCA9
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
CARBOXYLIC ACIDS
CORRELATIONS
CYCLOHEXIMIDE
DIABETES MELLITUS
DIET
FATS
GLUCOSE
HYDROFLUORIC ACID
HYPERGLYCEMIA
INSULIN
INTAKE
MICE
ONCOGENES
PANCREAS
SECRETION
SYNTHESIS
TOLERANCE
TRANSCRIPTION