The gene expression of GPER1 is low in fresh samples of papillary thyroid carcinoma (PTC), and in silico analysis.

Papillary thyroid cancer (PTC), whose incidence has been increasing in the last years, occurs more frequently in women. Experimental studies suggested that estrogen could be an important risk factor for the higher female incidence. In fact, it has been demonstrated that 17ß-estradiol (E2) could increase proliferation and dedifferentiation in thyroid follicular cells. Genomic estrogen responses are typically mediated through classical estrogen receptors, the α and ß isoforms, which have been described in normal and abnormal human thyroid tissue. Nevertheless, effects mediated through G protein estrogen receptor 1 (GPR30/GPER/GPER1), described in some thyroid cancer cell lines, could be partially responsible for the regulation of growth in normal cells. In this study, GPER1 gene and protein expression are described in non-malignant and in papillary thyroid cancer (PTC), as well as its association with clinical features of patients with PTC. The GPER1 expression was lower in PTC as compared to paired non-malignant thyroid tissues in fresh samples of PTC and in silico analysis of GEO and TCGA databases. In PTC cases of TCGA database, low GPER1 mRNA expression was independently associated with metastatic lymph nodes, female gender, and BRAF mutation. Besides, GPER1 mRNA levels were positively correlated with mRNA levels of thyroid differentiation genes. These results support the hypothesis that GPER1 have a role in PTC tumorigenesis and might be a potential target for its therapy. Further studies are needed to determine the functionality of these receptors in normal and diseased thyroid.

Panax ginseng metabolite (GIM-1) modulates the effects of monobutyl phthalate (MBP) on the GPR30/GPER1 canonical pathway in human Sertoli cells.

This study was performed to evaluate the effect of monobutyl phthalate (MBP) on GPR30-activated pathways in Sertoli cells. Additionally, we tested if GIM-1 (Panax ginseng metabolite) modulates MBP action. Human Sertoli cells (HSeC lineage) were exposed to MBP and/or GIM-1 for 30 min, 1, 12, and 48 h. Four experimental treatments were performed: control (DEMEM/F12 medium), MBP, GIM-1, and MBP + GIM-1. The results indicate that MBP activates GPR30, PKA, Src, EGFR, and the ERK1/2 proteins, while GIM-1 inhibits PKA, Src, ERK1/2, and the AKT pathway. MBP also enhances Cofilin expression, decreasing F-actin intensity on the cell surface in a short time. The combined exposure demonstrated a functional antagonism between compounds. Collectively, these data show that MBP activates GPR30 in Sertoli cells, and GIM-1 modulates this response, playing a protective role in Sertoli cells exposed to MBP.

The G protein-coupled oestrogen receptor, GPER1, mediates direct anti-inflammatory effects of oestrogens in human cholinergic neurones from the nucleus basalis of Meynert.

It has been well established, particularly in animal models, that oestrogens exert neuroprotective effects in brain areas linked to cognitive processes. A key protective role could reside in the capacity of oestrogen to modulate the inflammatory response. However, the direct neuroprotective actions of oestrogens on neurones are complex and remain to be fully clarified. In the present study, we took advantage of a previously characterised primary culture of human cholinergic neurones (hfNBM) from the foetal nucleus basalis of Meynert, which is known to regulate hippocampal and neocortical learning and memory circuits, aiming to investigate the direct effects of oestrogens under inflammatory conditions. Exposure of cells to tumour necrosis factor (TNF)α (10 ng mL-1 ) determined the activation of an inflammatory response, as demonstrated by nuclear factor-kappa B p65 nuclear translocation and cyclooxygenase-2 mRNA expression. These effects were inhibited by treatment with either 17ß-oestradiol (E2 ) (10 nmol L-1 ) or G1 (100 nmol L-1 ), the selective agonist of the G protein-coupled oestrogen receptor (GPER1). Interestingly, the GPER1 antagonist G15 abolished the effects of E2 in TNFα-treated cells, whereas the ERα/ERß inhibitor tamoxifen did not. Electrophysiological measurements in hfNBMs revealed a depolarising effect caused by E2 that was specifically blocked by tamoxifen and not by G15. Conversely, G1 specifically hyperpolarised the cell membrane and also increased both inward and outward currents elicited by a depolarising stimulus, suggesting a modulatory action on hfNBM excitability by GPER1 activation. Interestingly, pretreating cells with TNFα completely blocked the effects of G1 on membrane properties and also significantly reduced GPER1 mRNA expression. In addition, we found a peculiar subcellular localisation of GPER1 to focal adhesion sites that implicates new possible mechanisms of action of GPER1 in the neuronal perception of mechanical stimuli. The results obtained in the present study indicate a modulatory functional role of GPER1 with respect to mediating the oestrogen neuroprotective effect against inflammation in brain cholinergic neurones and, accordingly, may help to identify protective strategies for preventing cognitive impairments.

GPER1/GPR30 activation improves neuronal survival following global cerebral ischemia induced by cardiac arrest in mice.

Female sex steroids, particularly estrogens, contribute to the sexually dimorphic response observed in cerebral ischemic outcome, with females being relatively protected compared to males. Using a mouse model of cardiac arrest and cardiopulmonary resuscitation (CA/CPR), we previously demonstrated that estrogen neuroprotection is mediated in part by the estrogen receptor ß, with no involvement of estrogen receptor α. In this study we examined the neuroprotective effect of the novel estrogen receptor, G-protein coupled estrogen receptor 1 (GPER1/GPR30). Male mice administered the GPR30 agonist G1 exhibited significantly reduced neuronal injury in the hippocampal CA1 region and striatum. The magnitude of neuroprotection observed in G1 treated mice was indistinguishable from estrogen treated mice, implicating GPR30 in estrogen neuroprotection. Real-time quantitative RT-PCR indicates that G1 treatment increases expression of the neuroprotective ion channel, small conductance calcium-activated potassium channel 2. We conclude that GPR30 agonists show promise in reducing brain injury following global cerebral ischemia.