title: Increased glucose utilization and decreased fatty acid metabolism in myotubes from Glmp(gt/gt) mice.
abstract: Glycosylated lysosomal membrane protein (GLMP) has been reported to enhance the expression from a peroxisome proliferator-activated receptor alpha (PPARα) responsive promoter, but also to be an integral lysosomal membrane protein. Using myotubes established from wild-type and Glmp(gt/gt) mice, the importance of GLMP in skeletal muscle was examined. Glmp(gt/gt) myotubes expressed a more glycolytic phenotype than wild-type myotubes. Myotubes from Glmp(gt/gt) mice metabolized glucose faster and had a larger pool of intracellular glycogen, while oleic acid uptake, storage and oxidation were significantly reduced. Gene expression analyses indicated lower expression of three PPAR-isoforms, a co-regulator of PPAR (PGC1α) and several genes important for lipid metabolism in Glmp(gt/gt) myotubes. However, ablation of GLMP did not seem to substantially impair the response to PPAR agonists. In conclusion, myotubes established from Glmp(gt/gt) mice were more glycolytic than myotubes from wild-type animals, in spite of no differences in muscle fiber types in vivo.
authors.affiliation: a Department of Biosciences .
authors.forename: Xiang Yi
authors.initials: XY
authors.lastname: Kong
authors.affiliation: b Department of Pharmaceutical Biosciences , School of Pharmacy, University of Oslo , Oslo , Norway , and.
authors.forename: Yuan Zeng
authors.initials: YZ
authors.lastname: Feng
authors.affiliation: a Department of Biosciences .
authors.forename: Einar
authors.initials: E
authors.lastname: Eftestøl
authors.affiliation: b Department of Pharmaceutical Biosciences , School of Pharmacy, University of Oslo , Oslo , Norway , and.
authors.forename: Eili T
authors.initials: ET
authors.lastname: Kase
authors.affiliation: b Department of Pharmaceutical Biosciences , School of Pharmacy, University of Oslo , Oslo , Norway , and.
authors.forename: Hanne
authors.initials: H
authors.lastname: Haugum
authors.affiliation: a Department of Biosciences .
authors.forename: Winnie
authors.initials: W
authors.lastname: Eskild
authors.affiliation: b Department of Pharmaceutical Biosciences , School of Pharmacy, University of Oslo , Oslo , Norway , and.
authors.forename: Arild C
authors.initials: AC
authors.lastname: Rustan
authors.affiliation: b Department of Pharmaceutical Biosciences , School of Pharmacy, University of Oslo , Oslo , Norway , and.|c Department of Pharmacology , Institute of Clinical Medicine, University of Oslo and Oslo University Hospital , Oslo , Norway.
authors.forename: G Hege
authors.initials: GH
authors.lastname: Thoresen
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D005227:Fatty Acids / Q000378:metabolism*; D017353:Gene Deletion; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D005947:Glucose / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism; D019301:Oleic Acid / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D047492:Peroxisome Proliferator-Activated Receptors / Q000819:agonists / Q000378:metabolism
chemical_list: D005227:Fatty Acids; D008565:Membrane Proteins; C543310:NCU-G1 protein, mouse; D047492:Peroxisome Proliferator-Activated Receptors; D019301:Oleic Acid; D005947:Glucose
keywords: Cultured myotubes; Glycosylated lysosomal membrane protein; energy metabolism; peroxisome proliferator-activated receptor; skeletal muscle