Calpain-10 gene and protein expression in human skeletal muscle: effect of acute lipid-induced insulin resistance and type 2 diabetes.

Abstract

OBJECTIVE:

Our objective was to investigate the effect of lipid-induced insulin resistance and type 2 diabetes on skeletal muscle calpain-10 mRNA and protein levels.

RESEARCH DESIGN AND METHODS:

In the first part of this study, 10 healthy subjects underwent hyperinsulinemic euglycemic (4.5 mmol/liter) clamps for 6 h with iv infusion of either saline or a 20% Intralipid emulsion (Fresenius Kabi AG, Bad Homburg, Germany). Skeletal muscle biopsies were taken before and after 3- and 6-h insulin infusion and analyzed for calpain-10 mRNA and protein expression. In the second part of the study, muscle samples obtained after an overnight fast in 10 long-standing, sedentary type 2 diabetes patients, 10 sedentary, weight-matched, normoglycemic controls, and 10 age-matched, endurance-trained cyclists were analyzed for calpain-10 mRNA and protein content.

RESULTS:

Intralipid infusion in healthy subjects reduced whole body glucose disposal by approximately 50% (P<0.001). Calpain-10 mRNA (P=0.01) but not protein content was reduced after 6-h insulin infusion in both the saline and Intralipid emulsion trials. Skeletal muscle calpain-10 mRNA and protein content did not differ between the type 2 diabetes patients and normoglycemic controls, but there was a strong trend for total calpain-10 protein to be greater in the endurance-trained athletes (P=0.06).

CONCLUSIONS:

These data indicate that skeletal muscle calpain-10 expression is not modified by insulin resistance per se and suggest that hyperinsulinemia and exercise training may modulate human skeletal muscle calpain-10 expression.

• Authors: L Norton, T Parr, K Chokkalingam, R G Bardsley, H Ye, G I Bell, M M A L Pelsers, L J C van Loon, K Tsintzas
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 93 Issue 3 Pg. 992-8 (Mar 2008) ISSN: 0021-972X [Print] United States
• PMID: 18089694 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Fat Emulsions, Intravenous
• Glucose Transporter Type 4
• Insulin
• RNA, Messenger
• SLC2A4 protein, human
• Calpain
• calpain 10

Topics

• Adult
• Calpain (analysis, genetics)
• Diabetes Mellitus, Type 2 (metabolism)
• Fat Emulsions, Intravenous (pharmacology)
• Glucose Transporter Type 4 (physiology)
• Humans
• Insulin (blood)
• Insulin Resistance
• Male
• Middle Aged
• Muscle, Skeletal (chemistry, metabolism)
• RNA, Messenger (analysis)