TITLE:
Human skeletal muscle perilipin 2 and 3 expression varies with insulin sensitivity
AUTHORS:
Andreas Vigelsø, Clara Prats, Thorkil Ploug, Flemming Dela, Jørn W. Helge
KEYWORDS:
Lipid Metabolism, Insulin Sensitivity; Perilipin Proteins; Lipolysis; Human Skeletal Muscle; Lipotoxicity
JOURNAL NAME:
Journal of Biomedical Science and Engineering,
Vol.6 No.5A,
May
28,
2013
ABSTRACT:
Background:
Impaired insulin sensitivity may partly arise from a dysregulated lipid
metabolism in human skeletal muscle. This study investigates the expression
levels of perilipin 2, 3, and 5, and four key lipases in human skeletal muscle
from the subjects that exhibit a range from normal to very low insulin
sensitivity. Methods: 25 middle aged male participants were matched for lean
body mass and recruited into three groups; type 2 diabetes patients (T2D),
impaired glucose tolerance (IGT), and healthy sedentary controls (CON)
according to their glucose tolerance and VO2peak. A muscle biopsy
was obtained from vastus lateralis, and a two-step sequential euglycaemic-hyperinsulinaemic
clamp was performed. Muscle samples were analyzed by Western blot for
expression of perilipin 2, 3, 5, adipose triglyceride lipase (ATGL),
hormone-sensitive lipase (HSL), endothelial lipase (EL) and lipoprotein lipase
(LPL). Results: Perilipin 3 expression was higher in T2D compared to CON. Perilipin
2 expression was higher in CON than T2D. We observed
no difference in expression of perili pin 5, ATGL, HSL, EL or LPL between
the groups. Conclusions: In the present study the muscle perilipin 3 expression
and perilipin 2 expression varied markedly with insulin sensitivity. This
difference in perilipin expression may indicate that the lipid droplet
function and thus storage and release of fatty acid-vary with insulin sensitivity.