title: Age-related and depot-specific changes in white adipose tissue of growth hormone receptor-null mice.
abstract: Growth hormone receptor-null (GHR(-/-)) mice are dwarf, insulin sensitive, and long-lived in spite of increased adiposity. However, their adiposity is not uniform, with select white adipose tissue (WAT) depots enlarged. To study WAT depot-specific effects on insulin sensitivity and life span, we analyzed individual WAT depots of 12- and 24-month-old GHR(-) (/-) and wild-type (WT) mice, as well as their plasma levels of selected hormones. Adipocyte sizes and plasma insulin, leptin, and adiponectin levels decreased with age in both GHR(-) (/-) and WT mice. Two-dimensional gel electrophoresis proteomes of WAT depots were similar among groups, but several proteins involved in endocytosis and/or cytoskeletal organization (Ehd2, S100A10, actin), anticoagulation (S100A10, annexin A5), and age-related conditions (alpha2-macroglobulin, apolipoprotein A-I, transthyretin) showed significant differences between genotypes. Because Ehd2 may regulate endocytosis of Glut4, we measured Glut4 levels in the WAT depots of GHR(-) (/-) and WT mice. Inguinal WAT of 12-month-old GHR(-) (/-) mice displayed lower levels of Glut4 than WT. Overall, the protein changes detected in this study offer new insights into possible mechanisms contributing to enhanced insulin sensitivity and extended life span in GHR(-) (/-) mice.
authors.affiliation: Edison Biotechnology Institute, Ohio University, 1 Water Tower Dr., The Ridges, Athens, OH 45701. kopchick@ohio.edu.
authors.forename: Lucila
authors.initials: L
authors.lastname: Sackmann-Sala
authors.forename: Darlene E
authors.initials: DE
authors.lastname: Berryman
authors.forename: Ellen R
authors.initials: ER
authors.lastname: Lubbers
authors.forename: Han
authors.initials: H
authors.lastname: Zhang
authors.forename: Clare B
authors.initials: CB
authors.lastname: Vesel
authors.forename: Katie M
authors.initials: KM
authors.lastname: Troike
authors.forename: Elahu S
authors.initials: ES
authors.lastname: Gosney
authors.forename: Edward O
authors.initials: EO
authors.lastname: List
authors.forename: John J
authors.initials: JJ
authors.lastname: Kopchick
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000378:metabolism*; D052436:Adipose Tissue, White / Q000378:metabolism*; D000375:Aging / Q000502:physiology*; D000818:Animals; D015153:Blotting, Western; D004247:DNA / Q000235:genetics*; D004195:Disease Models, Animal; D015180:Electrophoresis, Gel, Two-Dimensional; D018507:Gene Expression Regulation, Developmental; D007333:Insulin Resistance; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009765:Obesity / Q000235:genetics / Q000378:metabolism; D011986:Receptors, Somatotropin / Q000235:genetics* / Q000378:metabolism
chemical_list: D011986:Receptors, Somatotropin; D004247:DNA
keywords: Adipose tissue depots; Aging; Endocytosis; Glut4.; Growth hormone receptor