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: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.
Project description:The treatment of advanced prostate cancer has been transformed by novel antiandrogen therapies such as enzalutamide. We identified glucocorticoid receptor (GR) activity as modulator of enzalutamite sensitivity in the VCaP prostate cancer cell line. The GR agonist dexamethasone was sufficient to confer enzalutamide resistance whereas a GR antagonist restored sensitivity. These expression profiling data demonstrate that GR transcriptional activity overlaps with that of AR in the VCAP model.
Project description:Vegetative cells of B. subtilis can recover from injury caused by high hydrostatic pressure (HHP) treatment at 250 MPa. DNA microarray analysis revealed that many ribosomal genes and translation relating factors (e.g. translation initiation factors) were induced during a growth-arrested phase after the HHP treatment. Expression of cold shock-responsive genes, whose products play key roles for efficient translation, and heat shock-responsive genes, whose product mediates the correct protein folding or degrades misfolded proteins, were also induced. In contrast, the expression of hpf, whose product (Hpf) is involved in ribosome inactivation through dimerization of 70S ribosomes, was repressed. Sucrose density gradient sedimentation analysis showed that ribosomes were dissociated in a pressure-dependent manner and then reconstructed during the growth-arrested phase. These results suggested that the translational machinery can be preferentially reconstructed in the HHP-injured cells. We also found that cell growth after HHP-induced injury was apparently inhibited by Mn2+ or Zn2+ supplemented to the recovery medium. Ribosome reconstruction in HHP-injured cells was significantly delayed in the presence of Mn2+ or Zn2+. Moreover, Zn2+ but not Mn2+ stimulated dimer formation of ribosomes in HHP-injured cells. This Zn2+-dependent accumulation of ribosome dimer was no longer observed in a Δhpf mutant lacking the functional Hpf. Furthermore, the growth recovery of the Δhpf mutant in the Zn2+-supplemented medium was faster than that of the parent strain. Thus, our results indicate that Zn2+ can prevent ribosome reconstruction by stimulating the Hpf-dependent ribosome dimerization, thereby inhibiting the growth recovery of the HHP-injured B. subtilis cells.