Increased expression of inflammation-related genes in cultured preadipocytes/stromal vascular cells from obese compared with non-obese Pima Indians

Aims/hypothesis: The specific contributions made by the various cell types in adipose tissue to obesity, particularly obesity-related inflammation, need to be clarified. The aim of this study was to elucidate the potential role of adipocyte precursor cells (preadipocytes/stromal vascular cells [SVC]). Methods: We performed Affymetrix oligonucleotide microarray expression profiling of cultured abdominal subcutaneous preadipocytes/SVC isolated from the adipose tissue of 14 non-obese ( BMI 25 +/- 4 kg/m(2)) and 14 obese ( 55 +/- 8 kg/m(2)) non-diabetic Pima Indian subjects. Quantitative real-time PCR (RT-PCR) was used to verify the differential expression of several genes in an independent group of subjects. Results: We identified 218 differentially expressed genes with p values less than 0.01. Microarray expression profiling revealed that the expression of inflammation-related genes was significantly upregulated in preadipocytes/SVC of obese individuals. Quantitative RT-PCR confirmed the upregulation of IL8, CTSS, ITGB2, HLA-DRA, CD53, PLA2G7 and MMP9 in preadipocytes/SVC of obese subjects. Conclusions/ interpretation: The upregulation of inflammation-related genes in preadipocytes/SVC of obese subjects may increase the recruitment of immune cells into adipose tissue and may also result in changes in the extracellular matrix ( tissue remodelling) to accommodate adipose tissue expansion in obesity.