Abstract
Background:Adipose tissue is a primary in vivo site of inflammation in obesity. Excess visceral adipose tissue (VAT), when compared to subcutaneous adipose tissue (SAT), imparts an increased risk of obesity-related comorbidities and mortality, and exhibits differences in inflammation. Defining depot-specific differences in inflammatory function may reveal underlying mechanisms of adipose-tissue-based inflammation.Methods:Stromovascular cell fractions (SVFs) from VAT and SAT from obese humans undergoing bariatric surgery were studied in an in vitro culture system with transcriptional profiling, flow cytometric phenotyping, enzyme-linked immunosorbent assay and intracellular cytokine staining.Results:Transcriptional profiling of SVF revealed differences in inflammatory transcript levels in VAT relative to SAT, including elevated interferon-γ (IFN-γ) transcript levels. VAT demonstrated a broad leukocytosis relative to SAT that included macrophages, T cells and natural killer (NK) cells. IFN-γ induced a proinflammatory cytokine expression pattern in SVF and adipose tissue macrophages (ATM). NK cells, which constitutively expressed IFN-γ, were present at higher frequency in VAT relative to SAT. Both T and NK cells from SVF expressed IFN-γ on activation, which was associated with tumor necrosis factor-α expression in macrophages.Conclusion:These data suggest involvement of NK cells and IFN-γ in regulating ATM phenotype and function in human obesity and a potential mechanism for the adverse physiologic effects of VAT.
Original language | English (US) |
---|---|
Pages (from-to) | 978-990 |
Number of pages | 13 |
Journal | International Journal of Obesity |
Volume | 33 |
Issue number | 9 |
DOIs | |
State | Published - Sep 2009 |
Keywords
- Adipose tissue
- IFN-γ
- Inflammation
- NK cells
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Endocrinology, Diabetes and Metabolism
- Nutrition and Dietetics