title: Fatty acids increase glucose uptake and metabolism in C2C12 myoblasts stably transfected with human lipoprotein lipase.
abstract: Cellular effects of FFA might differ from those of lipoprotein triglyceride (TG)-derived fatty acids (TGFA). The aim of the current study was to examine the relationship between lipoprotein lipase (LPL) expression, TGFA, or FFA availability and glucose metabolism in the absence of insulin in C2C12 myoblasts. Control myoblasts or myoblasts stably transfected with human lipoprotein lipase (C2/LPL; 15-fold greater LPL activity) were incubated for 12 h in fetal bovine serum-free medium in the absence or presence of Intralipid-20. Intracellular retention of labeled medium glucose was assessed in a subset of experiments. In the presence of Intralipid, medium glucose disappearance was increased in C2/LPL cells but not in control cells. In both cell types, glucose label retention in cellular TG was increased in the presence of Intralipid; incubation with albumin-bound oleate produced similar results. In the presence of Intralipid, the LPL hydrolytic inhibitor tetrahydrolipstatin blocked excess glucose retention in cellular TG but did not significantly decrease glucose disappearance in C2/LPL cells. Changes in glucose transport or hexokinase II did not explain the altered glucose disappearance in C2/LPL cells. Our results suggest that LPL overexpression in these cells leads to chronic metabolic adaptations that alter glucose uptake and retention.
authors.affiliation: Division of Endocrinology, Metabolism, and Diabetes, University of Colorado at Denver and Health Sciences Center, Denver, Colorado, USA.
authors.forename: Warren H
authors.initials: WH
authors.lastname: Capell
authors.forename: Isabel R
authors.initials: IR
authors.lastname: Schlaepfer
authors.forename: Pamela
authors.initials: P
authors.lastname: Wolfe
authors.forename: Peter A
authors.initials: PA
authors.lastname: Watson
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Bessesen
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Pagliassotti
authors.forename: Robert H
authors.initials: RH
authors.lastname: Eckel
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D005217:Fat Emulsions, Intravenous / Q000494:pharmacology*; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007783:Lactones / Q000494:pharmacology; D008071:Lipoprotein Lipase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008074:Lipoproteins / Q000378:metabolism; D051379:Mice; D018482:Muscle, Skeletal / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D032446:Myoblasts / Q000201:enzymology / Q000378:metabolism; D000077403:Orlistat; D014162:Transfection; D014280:Triglycerides / Q000378:metabolism
chemical_list: D005217:Fat Emulsions, Intravenous; D005230:Fatty Acids, Nonesterified; D007783:Lactones; D008074:Lipoproteins; D014280:Triglycerides; C030087:lipoprotein triglyceride; D000077403:Orlistat; D008071:Lipoprotein Lipase; D005947:Glucose