title: Insulin sensitivity is independent of lipid binding protein trafficking at the plasma membrane in human skeletal muscle: effect of a 3-day, high-fat diet.
abstract: The aim of the present study was to investigate lipid-induced regulation of lipid binding proteins in human skeletal muscle and the impact hereof on insulin sensitivity. Eleven healthy male subjects underwent a 3-day hypercaloric and high-fat diet regime. Muscle biopsies were taken before and after the diet intervention, and giant sarcolemmal vesicles were prepared. The high-fat diet induced decreased insulin sensitivity, but this was not associated with a relocation of FAT/CD36 or FABPpm protein to the sarcolemma. However, FAT/CD36 and FABPpm mRNA, but not the proteins, were upregulated by increased fatty acid availability. This suggests a time dependency in the upregulation of FAT/CD36 and FABPpm protein during high availability of plasma fatty acids. Furthermore, we did not detect FATP1 and FATP4 protein in giant sarcolemmal vesicles obtained from human skeletal muscle. In conclusion, this study shows that a short-term lipid-load increases mRNA content of key lipid handling proteins in human muscle. However, decreased insulin sensitivity after a high-fat diet is not accompanied with relocation of FAT/CD36 or FABPpm protein to the sarcolemma. Finally, FATP1 and FATP4 protein was located intracellularly but not at the sarcolemma in humans.
authors.affiliation: Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark;
authors.forename: Andreas B
authors.initials: AB
authors.lastname: Jordy
authors.affiliation: Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark;
authors.forename: Annette K
authors.initials: AK
authors.lastname: Serup
authors.affiliation: The Centre of Inflammation and Metabolism and The Centre for Physical Activity Research, Department of Infectious Diseases, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; and.
authors.forename: Kristian
authors.initials: K
authors.lastname: Karstoft
authors.affiliation: The Centre of Inflammation and Metabolism and The Centre for Physical Activity Research, Department of Infectious Diseases, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; and CFAS, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Henriette
authors.initials: H
authors.lastname: Pilegaard
authors.affiliation: Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark; bkiens@nexs.ku.dk.
authors.forename: Bente
authors.initials: B
authors.lastname: Kiens
authors.affiliation: Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark;
authors.forename: Jacob
authors.initials: J
authors.lastname: Jeppesen
mesh_terms: D001507:Beclomethasone; D002462:Cell Membrane / Q000502:physiology*; D004041:Dietary Fats / Q000008:administration & dosage*; D005227:Fatty Acids / Q000097:blood / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology; D050356:Lipid Metabolism / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000502:physiology*; D010101:Oxygen Consumption; D021381:Protein Transport / Q000502:physiology*; D055815:Young Adult
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D007328:Insulin; D001507:Beclomethasone
keywords: fatty acid transport; human muscle; insulin sensitivity; lipid binding proteins