GSK4716 enhances 5-HT1AR expression by glucocorticoid receptor signaling in hippocampal HT22 cells

OBJECTIVES

The serotonin (5-hydroxytryptamine, 5-HT) receptor 1A (5-HT1AR) is closely associated with serotonergic neurotransmission in the brain, being the most prevalent and widely distributed receptor of its kind. The purpose of this study is to investigate the regulation mechanism of 5-HT1AR by GSK4716.

METHODS

To investigate the mechanism of GSK4716-mediated 5-HT1AR regulation, we used hippocampus-derived HT22 cells expressing 5-HT1AR. The expression level of 5-HT1AR and associated proteins, were detected by reporter gene assay and western blotting.

RESULTS

GSK4716, an estrogen-related receptor gamma agonist increased 5-HT1AR expression by interacting with the GR, a repressor of 5-HT1AR transcription. Dexamethasone, a GR agonist, decreased the GSK4716-induced increase in 5-HT1AR, which was associated with an alteration in nuclear GR. Furthermore, GR antagonist RU486 reversed the effects induced by dexamethasone, including the elevation of nuclear GR levels and the reduction of 5-HT1AR transcription and expression.

CONCLUSION

The results could provide insight into the potential applications of small molecules, such as GSK4716, in the regulation of 5-HT1AR expression, which plays a role in serotonergic neurotransmission.

An Inverse Agonist of Estrogen-Related Receptor Gamma, GSK5182, Enhances Na(+)/I(-) Symporter Function in Radioiodine-Refractory Papillary Thyroid Cancer Cells

Previously, we reported that an inverse agonist of estrogen-related receptor gamma (ERRγ), GSK5182, enhances sodium iodide (Na⁺/I^-) symporter (NIS) function through mitogen-activated protein (MAP) kinase signaling in anaplastic thyroid cancer cells. This finding helped us to further investigate the effects of GSK5182 on NIS function in papillary thyroid cancer (PTC) refractory to radioactive iodine (RAI) therapy. Herein, we report the effects of ERRγ on the regulation of NIS function in RAI-resistant PTC cells using GSK5182. RAI-refractory BCPAP cells were treated with GK5182 for 24 h at various concentrations, and radioiodine avidity was determined with or without potassium perchlorate (KClO₄) as an NIS inhibitor. We explored the effects of GSK5182 on ERRγ, the mitogen-activated protein (MAP) kinase pathway, and iodide metabolism-related genes. We examined whether the MAP pathway affected GSK5182-mediated NIS function using U0126, a selective MEK inhibitor. A clonogenic assay was performed to evaluate the cytotoxic effects of I-131. GSK5182 induced an increase in radioiodine avidity in a dose-dependent manner, and the enhanced uptake was completely inhibited by KClO₄ in BCPAP cells. We found that ERRγ was downregulated and phosphorylated extracellular signal-regulated kinase (ERK)1/2 was upregulated in BCPAP cells, with an increase in total and membranous NIS and iodide metabolism-related genes. MEK inhibitors reversed the increase in radioiodine avidity induced by GSK5182. Clonogenic examination revealed the lowest survival in cells treated with a combination of GSK5182 and I-131 compared to those treated with either GSK518 or I-131 alone. We demonstrate that an inverse agonist of ERRγ, GSK5182, enhances the function of NIS protein via the modulation of ERRγ and MAP kinase signaling, thereby leading to increased responsiveness to radioiodine in RAI-refractory papillary thyroid cancer cells.

Candidate genes mediated by estrogen-related receptor γ in pancreatic β cells

Recent studies have established the importance of estrogen-related receptor γ (ERRγ) as a required participant for insulin secretion in pancreatic β cells. Key downstream genes of ERRγ remain unclear in the pancreatic β cell. To understand the molecular role of ERRγ and elucidate potential key candidate genes involved in pancreatic β cells, the eukaryotic expression plasmid containing mouse ERRγ was constructed and transfected into NIT-1 pancreatic β cells. Overexpression of ERRγ was confirmed by quantitative real-time reverse-transcription polymerase chain reaction and Western blot analyses. RNA-seq was conducted to get the gene expression profiling between the overexpression group cells and control cells. Differentially expressed genes (DEGs) were identified by edgR and subsequently analyzed by gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. We found that overexpression of ERRγ in pancreatic β cells enables regulation of the expression of certain genes involved in cell apoptosis and mitochondrial function, such as TFPT, Bcl7c, Dap, Thoc6, Ube2d3, ATP5H, MPV17, and NDUFA6. GO analysis revealed that the DEGs were mainly enriched in apoptotic process, cytoplasm, and protein binding. KEGG pathway analysis demonstrated that downregulated DEGs were mainly enriched in protein processing in endoplasmic reticulum, estrogen signaling pathway, and metabolic pathways. This study helps to further understand and reposition the molecular mechanisms of ERRγ in β cells.

ESRRG promoter hypermethylation as a diagnostic and prognostic biomarker in laryngeal squamous cell carcinoma

Background

Estrogen‐related receptor gamma (ESRRG) has been identified as a tumor suppressor gene in several cancers. We aimed to evaluate ESRRG promoter methylation in laryngeal squamous cell carcinoma (LSCC) and its relative clinical value in LSCC.

Methods

Bisulfite pyrosequencing assays were performed on 91 pairs of tumor and paracancer tissues from LSCC patients in China. The diagnostic value and overall survival (OS) were analyzed descriptively by receiver operating characteristic (ROC) curves and the Kaplan‐Meier methods, respectively.

Results

The ESRRG promoter was more frequently hypermethylated in tumor tissues than in adjacent tissues (P < 0.01). ESRRG promoter methylation was significantly increased in advanced T stage tumors (P < 0.01) and advanced clinical stage patients (P < 0.01). Moreover, the area under the ROC curve (AUC) value (0.81) indicated high discrimination accuracy. Furthermore, ESRRG hypermethylation was associated with poor OS, as confirmed by Kaplan‐Meier survival curves (P < 0.01).

Conclusion

Our study indicated that ESRRG promoter hypermethylation contributed to LSCC‐related risks, primarily tumor progression and survival prognosis, in patients. ESRRG promoter methylation could, therefore, be a diagnostic and prognostic biomarker in LSCC.

Identification of Selective ERRγ Inverse Agonists

GSK5182 (4) is currently one of the lead compounds for the development of estrogen-related receptor gamma (ERRγ) inverse agonists. Here, we report the design, synthesis, pharmacological and in vitro absorption, distribution, metabolism, excretion, toxicity (ADMET) properties of a series of compounds related to 4. Starting from 4, a series of analogs were structurally modified and their ERRγ inverse agonist activity was measured. A key pharmacophore feature of this novel class of ligands is the introduction of a heterocyclic group for A-ring substitution in the core scaffold. Among the tested compounds, several of them are potent ERRγ inverse agonists as determined by binding and functional assays. The most promising compound, 15g, had excellent binding selectivity over related subtypes (IC₅₀ = 0.44, >10, >10, and 10 μM at the ERRγ, ERRα, ERRβ, and ERα subtypes, respectively). Compound 15g also resulted in 95% transcriptional repression at a concentration of 10 μM, while still maintaining an acceptable in vitro ADMET profile. This novel class of ERRγ inverse agonists shows promise in the development of drugs targeting ERRγ-related diseases.

MiR-940 inhibits hepatocellular carcinoma growth and correlates with prognosis of hepatocellular carcinoma patients

Hepatocellular carcinoma (HCC) is among the leading causes of cancer-related death in China. Deregulation of microRNA (miRNA) contributes to HCC development by influencing cell growth, apoptosis, migration or invasion. It has been proved that miR-940 plays important roles in various cancers. Here we investigated the role of miR-940 in HCC. We found that miR-940 was remarkably decreased in HCC tissues and cell lines. Importantly, lower miR-940 expression in HCC tissues significantly correlated with the reduced patient's survival rate. Overexpression of miR-940 inhibited HCC cell line growth and induced cell apoptosis, and vice versa. Estrogen-related receptor gamma (ESRRG) was targeted by miR-940, and suppression of ESRRG inhibited HCC cell lines growth and induced cell apoptosis. In conclusion, we found that a lower level of miR-940 in HCC promoted cellular proliferation via ESRRG, which may lead to the short survival period of HCC patients.

The effects of PGC-1α on the proliferation and energy metabolism of malignant endometrial cancer cells

Background

It is well known that peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) plays an important role in tissue energy metabolism. However, the roles of PGC-1α in malignant endometrial cancer remain unknown.

Methods

Forty cases of endometrial carcinoma, 15 cases with proliferative endometrial tissues, and 21 cases with normal endometrial tissues were collected. Real-time polymerase chain reaction was used to detect the mRNA levels of PGC-1α and estrogen-related receptor gamma (ERRγ). ELISA (enzyme-linked immunosorbent assay) was used to detect the concentrations of pyruvate kinase and isocitrate dehydrogenase. The results were analyzed using medical statistical methods.

Results

The mRNA levels of PGC-1α and ERRγ in the endometrial carcinoma tissues and hyperplasic endometrial tissues were significantly greater than those in the normal endometria. The mRNA levels of PGC-1α and ERRγ in the endometrial carcinoma patients with type 2 diabetes were higher than those in patients without diabetes. The mRNA levels of PGC-1α and ERRγ in the endometrial adenocarcinomas increased with clinical staging, depth of myometrial invasion, and increases in the number of metastatic lymph nodes. The PGC-1α mRNA level was positively correlated with ERRγ in the endometrial carcinoma tissues. The mRNA levels of PGC-1α were positively correlated with the concentrations of pyruvate kinase and isocitrate dehydrogenase in the endometrial carcinoma tissues, and similar results were found for ERRγ.

Conclusion

Our results suggested that the upregulation of PGC-1α and ERRγ in endometrial cancer might be a requirement for cancer cell energy metabolism, which contributes to the development of endometrial cancer.

Computer-aided identification of novel protein targets of bisphenol A

The xenoestrogen bisphenol A (2,2-bis-(p-hydroxyphenyl)-2-propane, BPA) is a known endocrine-disrupting chemical used in the fabrication of plastics, resins and flame retardants, that can be found throughout the environment and in numerous every day products. Human exposure to this chemical is extensive and generally occurs via oral route because it leaches from the food and beverage containers that contain it. Although most of the effects related to BPA exposure have been linked to the activation of the estrogen receptor (ER), the mechanisms of the interaction of BPA with protein targets different from ER are still unknown. Therefore, the objective of this work was to use a bioinformatics approach to identify possible new targets for BPA. Docking studies were performed between the optimized structure of BPA and 271 proteins related to different biochemical processes, as selected by text-mining. Refinement docking experiments and conformational analyses were carried out using LigandScout 3.0 for the proteins selected through the affinity ranking (lower than -8.0kcal/mol). Several proteins including ERR gamma (-9.9kcal/mol), and dual specificity protein kinases CLK-4 (-9.5kcal/mol), CLK-1 (-9.1kcal/mol) and CLK-2 (-9.0kcal/mol) presented great in silico binding affinities for BPA. The interactions between those proteins and BPA were mostly hydrophobic with the presence of some hydrogen bonds formed by leucine and asparagine residues. Therefore, this study suggests that this endocrine disruptor may have other targets different from the ER.