Project description:Long-term pharmacological glucocorticoid therapy causes atrophy and hypofunction of the adrenal cortex. Following glucocorticoids withdrawal, a functional and anatomic regeneration take place, whose cellular and molecular mechanisms are poorly understood We used microarrays to detail the gene expression changes occurring during adrenal regeneration following administration of dexamethasone
Project description:Sixteen male Sprague-Dawley rats were randomly allocated into 2 groups (8 rats per group) as follows: the control group (CON) and the dexamethasone-treated group (DEXA). Dexamethasone-treated rats received a daily intraperitoneal injection of 1.5 mg/kg of dexamethasone for 5 days. All rats were fasted during the night following the fifth day. On the sixth day, the animals were killed by decapitation. In order to focus our investigation on metabolism-related genes, we developed a metabolism dedicated microarray tool: the Mitoligo. Using this microarray tool, we were able to determine that energy metabolism was deeply modified by dexamethasone treatment. Dexamethasone treatment to rats induces a complete switch of the metabolism toward a maximal rate of ATP synthesis. In this study, we show that substrate supplying for oxidative phosphorylation is greatly enhanced. We also confirm that oxidative phosphorylation capacity is increased by dexamethasone treatment. Keywords: hormonal treatment
Project description:The primary goal of this study was to determine the effect of metformin treatment during 5 days of bed rest in older adults and observe any residual effects of metformin treatment during recovery from this disuse period.
Project description:The RNA binding ability of the glucocorticoid receptor (GR) remains an understudied area of GR regulation. Through in vitro binding assays, we identified hairpin RNAs as GR's preferred binding motif. To study how GR-bound RNAs change with dexamethasone treatment, we first generated stable U2OS cells expressing wild-type GR-HaloTag. We then treated the cells with dexamethsone every hour over three hours, UV crosslinked, harvested, and pulled down GR using a specific and covalently-bound HaloTag ligand. GR-bound RNAs were then isolated, library prepped, and sequenced.
Project description:The human glucocorticoid receptor (GRα) is overexpressed at the molecular and protein level in malignant human adrenocortical cancers. A stable cell line model of GRα overexpression was established using the H295R human adrenocortical cancer cell line. The following results were obtained from gene expression profiling of H295R_GRα and H295R_Control (empty vector) cells following treatment with either a GRα agonist (dexamethasone), GRα antagonist (RU486) or vehicle (ethanol) control.
Project description:Skeletal muscle atrophy and weakness are major contributors to morbidity, prolonged recovery, and long-term disability across a wide range of diseases. Atrophy is caused by breakdown of sarcomeric proteins resulting in loss of muscle mass and strength. Molecular mechanism underlying the onset of muscle atrophy and its progression have been analysed in patients, mice, and cell culture but the complementarity of these model systems remains to be explored. Here, we applied deep-coverage transcriptomic and proteomic profiling to characterize dynamic changes during dexamethasone-induced atrophy in the widely used murine skeletal muscle cell line C2C12. Comparison with published datasets confirmed that muscle differentiation is well recapitulated in C2C12 myotubes. Under dexamethasone-induced treatment, this model was particularly suited to capture early atrophy events, prior to disassembly and degradation of sarcomeric proteins. We also identified alterations in mitochondrial gene expression and differential alternative splicing events during early-stage myotube atrophy. This dataset complements existing in vivo data and provides novel insights into the regulatory processes during skeletal muscle wasting.
Project description:Skeletal muscle atrophy and weakness are major contributors to morbidity, prolonged recovery, and long-term disability across a wide range of diseases. Atrophy is caused by breakdown of sarcomeric proteins resulting in loss of muscle mass and strength. Molecular mechanism underlying the onset of muscle atrophy and its progression have been analysed in patients, mice, and cell culture but the complementarity of these model systems remains to be explored. Here, we applied deep-coverage transcriptomic and proteomic profiling to characterize dynamic changes during dexamethasone-induced atrophy in the widely used murine skeletal muscle cell line C2C12. Comparison with published datasets confirmed that muscle differentiation is well recapitulated in C2C12 myotubes. Under dexamethasone-induced treatment, this model was particularly suited to capture early atrophy events, prior to disassembly and degradation of sarcomeric proteins. We also identified alterations in mitochondrial gene expression and differential alternative splicing events during early-stage myotube atrophy. This dataset complements existing in vivo data and provides novel insights into the regulatory processes during skeletal muscle wasting.
Project description:The human glucocorticoid receptor (GRα) is overexpressed at the molecular and protein level in malignant human adrenocortical cancers. A stable cell line model of GRα overexpression was established using the H295R human adrenocortical cancer cell line. The following results were obtained from gene expression profiling of H295R_GRα and H295R_Control (empty vector) cells following treatment with either a GRα agonist (dexamethasone), GRα antagonist (RU486) or vehicle (ethanol) control. H295R_GRα and H295R_Control (empty vector) cells were treated in triplicate for 6 hours with dexamethasone 100 nM, RU486 100 nM or vehicle (ethanol) control.