title: Diet-induced obesity in stem cell antigen-1 KO mice.
abstract: Stem Cell Antigen-1 (Sca-1) is a member of the lymphocyte-activated protein 6 family and has served as a marker for the identification of stem cells in various tissues, including fat depots. In vitro and in vivo studies suggest the possible involvement of Sca-1 in adipogenic differentiation and link Sca-1 antigenicity with adipocyte progenitors. Previously, we showed that Sca-1-enriched populations of ear mesenchymal stem cells possess enhanced capacity to differentiate into adipocytes. Additionally, we determined the natural frequency and localization of Sca-1-positive progenitor/stem cells in brown and white fat in situ. The present study addressed the question whether Sca-1 deficiency alters the white adipose tissue response to a high-saturated-fat diet. Our results show that Sca-1 null mice (Sca-1(-/-)) fed high-fat diet developed obesity equally well as wild-type mice, suggesting either an indirect in vivo effect of Sca-1 or a compensatory response to Sca-1 deficiency. However, contrary to wild-type mice, high fat diet-fed Sca-1(-/-) mice showed no alterations in serum adipocytokines. The data lead to the conclusion that Sca-1 is either redundant or a nonessential marker of adipose progenitor/stem cells. Nevertheless, since Sca-1-deficient mice displayed elevated blood glucose at fasting and exhibited glucose intolerance and insulin resistance, Sca-1 has subtle effects on adipose function. Thus, the Sca-1-deficient mice may provide a useful model for metabolic studies.
authors.affiliation: Regenerative Biology Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana 70808, USA.
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Staszkiewicz
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Gimble
authors.forename: Marilyn A
authors.initials: MA
authors.lastname: Dietrich
authors.forename: Barbara
authors.initials: B
authors.lastname: Gawronska-Kozak
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000378:metabolism*; D054392:Adipokines / Q000097:blood; D052436:Adipose Tissue, White / Q000166:cytology / Q000378:metabolism*; D050154:Adiposity / Q000235:genetics*; D000818:Animals; D000950:Antigens, Ly / Q000235:genetics; D001786:Blood Glucose; D059305:Diet, High-Fat; D055786:Gene Knockout Techniques; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008565:Membrane Proteins / Q000172:deficiency* / Q000235:genetics; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009765:Obesity / Q000097:blood* / Q000235:genetics
chemical_list: D054392:Adipokines; D000950:Antigens, Ly; D001786:Blood Glucose; D007328:Insulin; C074650:Ly6a protein, mouse; D008565:Membrane Proteins