Project description:Insulin resistance is a common metabolic abnormality in women with PCOS and leads to an elevated risk of type 2 diabetes. Studies have shown that thiazolidinediones (TZD) improve metabolic disturbances in PCOS patients. We hypothesized that the effect of TZD in PCOS is in part mediated by changes in the transcriptional profile of muscle favoring insulin sensitivity. Using Affymetrix microarrays, we examined the effect of pioglitazone (30 mg/day for 16 weeks) on gene expression in skeletal muscle of 10 obese women with PCOS metabolically characterized by a euglycemic-hyperinsulinemic clamp. Moreover, we explored gene expression changes between these PCOS patients before treatment and 13 healthy control women. Treatment with pioglitazone improved insulin-stimulated total, oxidative and non-oxidative glucose metabolism, and reduced fasting serum insulin (all p < 0.05). Global pathway analysis using Gene Map Annotator and Pathway Profiler (GenMAPP 2.1) and Gene Set Enrichment Analysis (GSEA 2.0.1) revealed a significant upregulation of genes involved in mitochondrial oxidative phosphorylation (OXPHOS), ribosomal proteins, mRNA processing reactome, translation factors, and proteasome complexes in PCOS patients after pioglitazone therapy. Quantitative real-time PCR suggested that upregulation of OXPHOS genes was mediated by an increase in PGC-1M-NM-1 expression (p < 0.05). Expression of genes involved in ribosomal proteins and OXPHOS was down-regulated in PCOS patients before treatment compared to matched healthy women using GenMAPP 2.1 and GSEA 2.1. These data indicate that pioglitazone therapy restores insulin sensitivity in part by a coordinated upregulation of genes involved in mitochondrial oxidative metabolism and protein biosynthesis in skeletal muscle of PCOS. These transcriptional effects of pioglitazone therapy may contribute to prevent the onset of type 2 diabetes in these women. Experiment Overall Design: Ten obese women of reproductive age with PCOS participated in the study to test the effect of pioglitazone therapy (data set 1). To test if pioglitazone ameliorate existing defects in PCOS patients, the expression profile of the 10 PCOS patients before treatment were compared to the same cohort of 13 control subjects (data set 2).
Project description:Insulin resistance is a common metabolic abnormality in women with PCOS and leads to an elevated risk of type 2 diabetes. Studies have shown that thiazolidinediones (TZD) improve metabolic disturbances in PCOS patients. We hypothesized that the effect of TZD in PCOS is in part mediated by changes in the transcriptional profile of muscle favoring insulin sensitivity. Using Affymetrix microarrays, we examined the effect of pioglitazone (30 mg/day for 16 weeks) on gene expression in skeletal muscle of 10 obese women with PCOS metabolically characterized by a euglycemic-hyperinsulinemic clamp. Moreover, we explored gene expression changes between these PCOS patients before treatment and 13 healthy control women. Treatment with pioglitazone improved insulin-stimulated total, oxidative and non-oxidative glucose metabolism, and reduced fasting serum insulin (all p < 0.05). Global pathway analysis using Gene Map Annotator and Pathway Profiler (GenMAPP 2.1) and Gene Set Enrichment Analysis (GSEA 2.0.1) revealed a significant upregulation of genes involved in mitochondrial oxidative phosphorylation (OXPHOS), ribosomal proteins, mRNA processing reactome, translation factors, and proteasome complexes in PCOS patients after pioglitazone therapy. Quantitative real-time PCR suggested that upregulation of OXPHOS genes was mediated by an increase in PGC-1α expression (p < 0.05). Expression of genes involved in ribosomal proteins and OXPHOS was down-regulated in PCOS patients before treatment compared to matched healthy women using GenMAPP 2.1 and GSEA 2.1. These data indicate that pioglitazone therapy restores insulin sensitivity in part by a coordinated upregulation of genes involved in mitochondrial oxidative metabolism and protein biosynthesis in skeletal muscle of PCOS. These transcriptional effects of pioglitazone therapy may contribute to prevent the onset of type 2 diabetes in these women. Keywords: PCOS, microarray, global pathway analysis, insulin resistance, pioglitazone, protein metabolism, mitochondrial oxidative metabolism
Project description:Polycystic ovary syndrome (PCOS) is an endocrine and metabolic disorder affecting women of reproductive age. The main features of PCOS are hyperandrogenism and irregular menstrual cycles together with metabolic dysfunctions including abdominal obesity, dyslipidemia and an increased risk of developing type 2 diabetes. Despite the high prevalence of >15%, the pathophysiology of the syndrome is unclear. Gene expression array data from skeletal muscle and adipose tissue have provided some information about dysregulated metabolic pathways in women with PCOS, but the transcriptomic data need to be verified by proteomics to advance our understanding of PCOS. Skeletal muscle and adipose tissue biopsies from 10 women with PCOS and 10 controls were subjected to global proteomic analysis. Protein expression differences between cases and controls were based on Student’s t-test and corrected for multiple testing. In total, we identified 5000 proteins in adipose tissue and 3480 proteins in skeletal muscle. After correction for multiple testing, 74 proteins with q < 0.05 corresponding to 72 unique proteins were found to be differentially expressed in adipose tissue from women with PCOS versus controls. And, 123 proteins with q < 0.05 corresponding to 120 unique proteins were found to be differentially expressed in skeletal muscle from women with PCOS versus control. We then applied pathway analysis to the total protein and phosphopeptide data using PRISM and Enrichr.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Polycystic ovary syndrome (PCOS) is characterised by a hormonal imbalance affecting the reproductive and metabolic health of reproductive-aged women. Exercise is often recommended as a first-line therapy for women with PCOS to help improve their overall health however, women with PCOS are resistant to the metabolic benefits of exercise training. Here, we aimed to gain insight into the mechanisms responsible for such resistance to exercise in PCOS. We employed an in vitro approach with electrical pulse stimulation (EPS) of cultured skeletal muscle cells to explore whether muscle cells from women with PCOS have an altered gene expression signature in response to muscle contraction. Following EPS, 4,719 genes were differentially expressed (FDR < 0.05) in myotubes from women with PCOS compared to only 173 in healthy control women. Both groups included genes involved in skeletal muscle contraction. We also determined the effect of two transforming growth factor-beta ligands that are elevated in plasma of women with PCOS, the transforming growth factor beta-1 (TGFβ1) and the anti-müllerian hormone (AMH), alone and on the EPS-induced response. While AMH (30 ng/ml) had no effect, TGFβ1 (5 ng/ml) induced the expression of extracellular matrix genes and impaired the exercise-like gene expression signature in myotubes from women with and without PCOS in response to EPS by interfering with key processes related to muscle contraction, calcium transport and actin filament. Collectively, our findings suggest that while the fundamental gene expression responses of skeletal muscle to contraction is intact in PCOS, elevated circulating factors like TGFβ1 may be responsible for the impaired adaptation to exercise intervention in women with PCOS.
Project description:The aim of this study was to gain further insight into the mechanisms leading to metabolic dysfunction in skeletal muscle in PCOS, and to determine whether primary myotubes retain the gene expression signature of PCOS in vivo. We investigated the transcriptomic profile of skeletal muscle tissue and primary myotube cultures from insulin resistant women with PCOS compared to healthy controls.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:Gene methylation profiling of immortalized human mesenchymal stem cells comparing HPV E6/E7-transfected MSCs cells with human telomerase reverse transcriptase (hTERT)- and HPV E6/E7-transfected MSCs. hTERT may increase gene methylation in MSCs. Goal was to determine the effects of different transfected genes on global gene methylation in MSCs.