Project description:Insulin resistance and Type 2 Diabetes Mellitus (T2DM) are associated with increased adipocyte size, altered secretory pattern and decreased differentiation of preadipocytes. To identify the underlying molecular processes in preadipocytes of T2DM patients that are a characteristic of the development of T2DM, preadipocyte cell cultures were prepared from subcutaneous fat biopsies of T2DM patients and compared with age- and BMI matched control subjects. Gene expression profiling showed changed expression of transcription factors involved in adipogenesis and in extracellular matrix remodeling, actin cytoskeleton and integrin signaling genes, which indicated decreased capacity to differentiate. Additionally, genes involved in insulin signaling and lipid metabolism were down-regulated, and inflammation/apoptosis was up-regulated in T2DM preadipocytes. The down-regulation of genes involved in differentiation can provide a molecular basis for the reduced adipogenesis of preadipocytes of T2DM subjects, leading to reduced formation of adipocytes in subcutaneous fat depots, and ultimately leading to ectopic fat storage. 7 T2DM preadipocyte samples and 9 age- and BMI-matched control samples were hybridized using 70-mer oligonucleotide microarrays. Samples were labeled with either Cy3 or Cy5. A total of 20 arrays were used including dye swop. Per array, a T2DM sample was hybridized with a control sample of the same gender and matched based on age and BMI. To ensure hybridization of two samples with the same gender, three T2DM (5064, 5128, 5395) and one control sample (5616) were used twice and listed as technical replicates.
