title: Pathways regulated by glucocorticoids in omental and subcutaneous human adipose tissues: a microarray study.
abstract: Glucocorticoids (GC) are powerful regulators of adipocyte differentiation, metabolism, and endocrine function and promote the development of upper body obesity, especially visceral fat stores. To provide a comprehensive understanding of how GC affect adipose tissue and adipocyte function, we analyzed patterns of gene expression (HG U95 Affymetrix arrays) after culture of abdominal subcutaneous (Abd sc) and omental (Om) adipose tissues from severely obese subjects (3 F, 1 M) in the presence of insulin or insulin (7 nM) plus dexamethasone (Dex, 25 nM) for 7 days. About 20% (561 genes in Om and 569 genes in sc) of 2,803 adipose expressed genes were affected by long-term GC. While most of the genes (90%) were commonly regulated by Dex in both depots, 26 in Om and 34 in Abd sc were affected by Dex in only one depot. 60% of the commonly upregulated genes were involved in metabolic pathways and were expressed mainly in adipocytes. Dex suppressed genes in immune/inflammatory (IL-6, IL-8, and MCP-1, expressed in nonadipocytes) and proapoptotic pathways, yet induced genes related to the acute-phase response (SAA, factor D, haptoglobin, and RBP4, expressed in adipocytes) and stress/defense response. Functional classification analysis showed that Dex also induced expression levels of 22 transcription factors related to insulin action and lipogenesis (LXRα, STAT5α, SREBP1, and FoxO1) and immunity/adipogenesis (TSC22D3) while suppressing 17 transcription factors in both depots. Overall, these studies reveal the powerful effects of GC on gene networks that regulate many key functions in human adipose tissue.
authors.affiliation: Division of Endocrinology, Diabetes, and Nutrition, Department of Medicine, Boston University School of Medicine, 650 Albany St., Boston, MA 02118, USA. mijlee@bu.edu
authors.forename: Mi-Jeong
authors.initials: MJ
authors.lastname: Lee
authors.forename: Da-Wei
authors.initials: DW
authors.lastname: Gong
authors.forename: Bryan F
authors.initials: BF
authors.lastname: Burkey
authors.forename: Susan K
authors.initials: SK
authors.lastname: Fried
mesh_terms: D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism; D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001808:Blood Vessels / Q000378:metabolism; D050260:Carbohydrate Metabolism / Q000187:drug effects / Q000235:genetics; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D050356:Lipid Metabolism / Q000187:drug effects / Q000235:genetics; D008297:Male; D046228:Microarray Analysis; D008875:Middle Aged; D009852:Omentum / Q000378:metabolism*; D009924:Organ Culture Techniques; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D017154:Stromal Cells / Q000378:metabolism; D050151:Subcutaneous Fat / Q000187:drug effects / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects; D055815:Young Adult
chemical_list: D000893:Anti-Inflammatory Agents; D005938:Glucocorticoids; D012313:RNA; D003907:Dexamethasone