title: Adult-onset degeneration of adipose tissue in mice deficient for the Sox8 transcription factor.
abstract: Although the transcription factor Sox8 is broadly expressed during embryogenesis in developing ectodermal and mesodermal tissues, mice develop surprisingly normally in the absence of Sox8. Phenotypes in adult Sox8-deficient mice include mild osteopenia, late-onset male infertility, and reduced weight. We show here that progressive degeneration of adipose tissue in adult Sox8-deficient mice significantly contributes to weight reduction. Although serum levels of leptin, IGF-1, and noradrenaline were altered in Sox8-deficient mice, these changes could not explain the observed phenotype. Other serum parameters, including indicators of glucose metabolism, were largely normal. However, expression of the preadipocyte marker Pref-1 was elevated in adipose tissues of Sox8-deficient mice. This increase correlated with an impaired differentiation of Sox8-deficient fibroblasts to adipocytes in culture, a defect that could be rescued by reintroducing Sox8 into the cells. Furthermore, Sox8 levels were higher in mesodermal precursors than in mature adipocytes. We postulate a precursor-intrinsic role of Sox8 during replenishment of the adipocyte pool in adult mice and assume that disturbance of this function significantly contributes to adipose tissue degeneration in Sox8-deficient mice.
authors.affiliation: Institut für Biochemie, Emil-Fischer-Zentrum, Universität Erlangen, Erlangen, Germany.
authors.forename: Sabine I E
authors.initials: SI
authors.lastname: Guth
authors.forename: Katy
authors.initials: K
authors.lastname: Schmidt
authors.forename: Andreas
authors.initials: A
authors.lastname: Hess
authors.forename: Michael
authors.initials: M
authors.lastname: Wegner
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000502:physiology*; D000273:Adipose Tissue / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010641:Phenotype; D055757:SOXE Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D055757:SOXE Transcription Factors; D007334:Insulin-Like Growth Factor I