Transcription profiling of myotubes from patients with type 2 diabetes

Microarray-based studies of skeletal muscle from patients with type 2 diabetes and high-risk individuals have demonstrated that insulin resistance and reduced mitochondrial biogenesis co-exist early in the pathogenesis of type 2 diabetes independent of hyperglycaemia and obesity. It is unknown whether reduced mitochondrial biogenesis or other transcriptional alterations co-exist with impaired insulin-responsiveness in primary human muscle cells from patients with type 2 diabetes. Results: No single gene was differently expressed after correction for multiple testing, and no biological pathway was differently expressed using both approaches for global pathway analysis. In particular, we found no evidence for differential expression of genes involved in mitochondrial oxidative metabolism. Consistently, there was no difference in mRNA levels of genes known to mediate the transcriptional control of mitochondrial biogenesis, PPARGC1A and NRF-1, or in mitochondrial mass between diabetic and control myotubes. Keywords: Cell culture, genetic, oxidative phosphorylation, microarray, skeletal muscle, type 2 diabetes Human Genome U95Av2 GeneChips (Affymetrix) was used for ten obese patients with type 2 diabetes and ten healthy control subjects.With global pathway analysis with Gene Map Annotator and Pathway Profiler (GenMapp 2.1) and Gene Set Enrichment Analysis (GSEA 2.0.1), we examined transcript levels in myotubes established from obese patients with type 2 diabetes and matched obese healthy subjects, who have been extensively metabolically characterized both in vivo and in vitro.