piperidines and 4-(2-phenyl-5-7-bis(trifluoromethyl)pyrazolo(1-5-a)pyrimidin-3-yl)phenol

Estrogen receptors (ERs) regulate the development of the growth plate (GP) by binding to estrogen, a phenomenon that determines the growth of skeletal bone. However, the exact mechanisms underlying the regulatory effects of ERs on axial and appendicular growth plates during puberty remain unclear. In the present study, the strategy of ERβ blocking resulted in increased longitudinal elongation of the appendicular bone (P < 0.01), whereas ERα blocking suppressed appendicular elongation (P < 0.05). Blocking both ERs did not have opposite effects on axial longitudinal growth. The expression of chondrocyte proliferation genes including collagen II, aggrecan, and Sox9 and hypertrophic marker genes including collagen X, MMP13, and Runx2 was significantly increased in the growth plate of female mice treated with ERβ antagonist compared with that in the GP of control mice (P < 0.05). There were no significant differences in local insulin-like growth factor 1 (IGF-1) expression among these groups (P > 0.05), and Indian hedgehog protein (Ihh) and parathyroid-related protein (PTHrP) expressions differed among these groups (P < 0.05). ERs appeared not to affect axial bone growth during puberty in female mice (P > 0.05). Our data show that the blocking of different ER subtypes might have a region-specific influence on longitudinal appendicular and axial growth.

Topics: Animals; Bone Development; Chondrocytes; Female; Mice, Inbred C57BL; Piperidines; Pyrazoles; Pyrimidines; Random Allocation; Receptors, Estrogen; Sexual Maturation

Estrogen receptor-alpha (ERα) and -beta (ERβ) occur in key elements of the brain gluco-homeostatic network in both sexes, including the hindbrain dorsal vagal complex (DVC), but the influence of distinct receptor populations on this critical function is unclear. The ventromedial hypothalamic nucleus (VMN) maintains glucose balance by integrating nutrient, endocrine, and neurochemical cues, including metabolic sensory information supplied by DVC A2 noradrenergic neurons. Current research utilized the selective ERα and ERβ antagonists MPP and PHTPP to characterize effects of DVC ERs on VMN norepinephrine (NE) activity and metabolic neurotransmitter signaling in insulin-induced hypoglycemic (IIH) male rats. Data show that ERβ inhibits VMN glycogen synthase and stimulates phosphorylase protein expression, while attenuating hypoglycemic augmentation of glycogen content. Furthermore, both ERs attenuate VMN glucose concentrations during IIH. Hypoglycemic up-regulation of nitric oxide (NO) and brain-derived neurotrophic factor (BDNF) signaling was correspondingly driven by ERα or -β, whereas GABA and steroidogenic factor-1 were respectively suppressed independently of ER input or by ERβ. IIH intensified VMN NE accumulation by ERβ-dependent mechanisms, but did not alter NE levels in other gluco-regulatory loci. ERβ amplified the magnitude of insulin-induced decline in blood glucose. Both ERs regulate corticosterone, but not glucagon secretion during IIH and oppose hypoglycemic diminution of circulating free fatty acids. These findings identify distinguishing versus common VMN functions targeted by DVC ERα and -β. Sex differences in hypoglycemic VMN NE accumulation, glycogen metabolism, and transmitter signaling may involve, in part, discrepant regulatory involvement or differential magnitude of impact of these hindbrain ERs.

Topics: Animals; Brain-Derived Neurotrophic Factor; Corticosterone; Glucose; Glycogen; Hypoglycemia; Male; Nitric Oxide; Norepinephrine; Piperidines; Pyrazoles; Pyrimidines; Rats; Rats, Sprague-Dawley; Receptors, Estrogen; Rhombencephalon; Ventromedial Hypothalamic Nucleus

Neural substrates for estrogen regulation of glucose homeostasis remain unclear. Female rat dorsal vagal complex (DVC) A2 noradrenergic neurons are estrogen- and metabolic-sensitive. The ventromedial hypothalamic nucleus (VMN) is a key component of the brain network that governs counter-regulatory responses to insulin-induced hypoglycemia (IIH). Here, the selective estrogen receptor-alpha (ERα) or -beta (ERβ) antagonists MPP and PHTPP were administered separately to the caudal fourth ventricle to address the premise that these hindbrain ER variants exert distinctive control of VMN reactivity to IIH in the female sex. Data show that ERα governs hypoglycemic patterns of VMN astrocyte glycogen metabolic enzyme, e.g. glycogen synthase and phosphorylase protein expression, whereas ERβ mediates local glycogen breakdown. DVC ERs also regulate VMN neurotransmitter signaling of energy sufficiency [γ-aminobutyric acid] or deficiency [nitric oxide, steroidogenic factor-1] during IIH. Neither hindbrain ER mediates IIH-associated diminution of VMN norepinephrine (NE) content. Both ERs oppose hypoglycemic hyperglucagonemia, while ERβ contributes to reduced corticosterone output. Outcomes reveal that input from the female hindbrain to the VMN is critical for energy reserve mobilization, metabolic transmitter signaling, and counter-regulatory hormone secretion during hypoglycemia, and that ERs control those cues. Evidence that VMN NE content is not controlled by hindbrain ERα or -β implies that these receptors may regulate VMN function via NE-independent mechanisms, or alternatively, that other neurotransmitter signals to the VMN may control local substrate receptivity to NE.

Topics: Animals; Brain-Derived Neurotrophic Factor; Estrogen Receptor Antagonists; Female; Glycogen; Hypoglycemia; Nitric Oxide Synthase Type I; Piperidines; Pyrazoles; Pyrimidines; Rats; Receptors, Estrogen; Rhombencephalon; Steroidogenic Factor 1; Ventromedial Hypothalamic Nucleus

Flavonoids are bioactive compounds that are known to be neuroprotective against glutamate-mediated excitotoxicity, one of the major causes of neurodegeneration. The mechanisms underlying these effects are unresolved, but recent evidence indicates flavonoids may modulate estrogen signaling, which can delay the onset and ameliorate the severity of neurodegenerative disorders. Furthermore, the roles played by glial cells in the neuroprotective effects of flavonoids are poorly understood. The aim of this study was to investigate the effects of the flavonoid agathisflavone (FAB) in primary neuron-glial co-cultures from postnatal rat cerebral cortex. Compared to controls, treatment with FAB significantly increased the number of neuronal progenitors and mature neurons, without increasing astrocytes or microglia. These pro-neuronal effects of FAB were suppressed by antagonists of estrogen receptors (ERα and ERβ). In addition, treatment with FAB significantly reduced cell death induced by glutamate and this was associated with reduced expression levels of pro-inflammatory (M1) microglial cytokines, including TNFα, IL1β and IL6, which are associated with neurotoxicity, and increased expression of IL10 and Arginase 1, which are associated with anti-inflammatory (M2) neuroprotective microglia. We also observed that FAB increased neuroprotective trophic factors, such as BDNF, NGF, NT4 and GDNF. The neuroprotective effects of FAB were also associated with increased expression of glutamate regulatory proteins in astrocytes, namely glutamine synthetase (GS) and Excitatory Amino Acid Transporter 1 (EAAT1). These findings indicate that FAB acting via estrogen signaling stimulates production of neurons in vitro and enhances the neuroprotective properties of microglia and astrocytes to significantly ameliorate glutamate-mediated neurotoxicity.

Topics: Animals; Astrocytes; Biflavonoids; Cell Death; Cerebral Cortex; Coculture Techniques; Cytokines; Excitatory Amino Acid Transporter 1; Fabaceae; Glutamate-Ammonia Ligase; Glutamic Acid; Microglia; Nerve Degeneration; Nerve Growth Factors; Neurogenesis; Neurons; Neuroprotective Agents; Piperidines; Primary Cell Culture; Pyrazoles; Pyrimidines; Rats

Topics: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; Animals; Enzyme Inhibitors; Estradiol; Estrogen Receptor alpha; Estrogen Receptor Modulators; Estrogens; Excitatory Postsynaptic Potentials; Female; Hippocampus; Male; Memory; Mice; Neuronal Plasticity; Neurons; Phosphorylation; Piperidines; Pyrazoles; Pyrimidines; Rats; Rats, Sprague-Dawley; rho-Associated Kinases; Sex Characteristics; Spatial Learning; Synapses

The magnitude of antinociception elicited by intrathecal endomorphin 2 (EM2), an endogenous mu-opioid receptor (MOR) ligand, varies across the rat estrous cycle. We now report that phasic changes in analgesic responsiveness to spinal EM2 result from plastic interactions within a novel membrane-bound oligomer containing estrogen receptors (mERs), aromatase (aka estrogen synthase), metabotropic glutamate receptor 1 (mGluR1), and MOR. During diestrus, spinal mERs, activated by locally synthesized estrogens, act with mGluR1 to suppress spinal EM2/MOR antinociception. The emergence of robust spinal EM2 antinociception during proestrus results from the loss of mER-mGluR1 suppression, a consequence of altered interactions within the oligomer. The chemical pairing of aromatase with mERs within the oligomer containing MOR and mGluR1 allows estrogens to function as intracellular messengers whose synthesis and actions are confined to the same signaling oligomer. This form of estrogenic signaling, which we term "oligocrine," enables discrete, highly compartmentalized estrogen/mER-mGluR1 signaling to regulate MOR-mediated antinociception induced by EM2. Finally, spinal neurons were observed not only to coexpress MOR, mERα, aromatase, and mGluR1 but also be apposed by EM2 varicosities. This suggests that modulation of spinal analgesic responsiveness to exogenous EM2 likely reflects changes in its endogenous analgesic activity. Analogous suppression of spinal EM2 antinociception in women (eg, around menses, comparable with diestrus in rats) as well as the (pathological) inability to transition out of that suppressed state at other menstrual cycle stages could underlie, at least in part, the much greater prevalence and severity of chronic pain in women than men.

Topics: Analgesics, Opioid; Animals; Aromatase; Benzimidazoles; Enzyme Inhibitors; Estrogen Receptor Modulators; Estrogens; Estrous Cycle; Excitatory Amino Acid Agents; Fadrozole; Female; Injections, Spinal; Oligopeptides; Piperidines; Pyrazoles; Pyrimidines; Rats; Rats, Sprague-Dawley; Receptors, Metabotropic Glutamate; Receptors, Opioid, mu; Spinal Cord; Thiazoles

Estrogen was reported to protect against obesity, however the mechanism remains unclear. We aimed to investigate the impact of 17β-estradiol (17β-E2) on triglyceride metabolism in adipocytes with or without lipopolysacchride (LPS) stimulating, providing novel potential mechanism for estrogen action.. 3T3-L1 adipocytes were cultured and differentiated into mature adipocytes in vitro. The differentiated 3T3-L1 cells were divided into six groups: (i) control group, treated with 0.1% DMSO alone; (ii) 17β-E2 group, treated with 1, 0.1, or 0.001 μM 17β-E2 for 48 h; (iii) 17β-E2 plus MPP group, pre-treated with 10 μM MPP (a selective ERα receptor inhibitor) for 1 h, then incubated with 1 μM 17β-E2 for 48 h; (iv) 17β-E2 plus PHTPP group, pre-treated with 10 μM PHTPP (a selective ERβ receptor inhibitor), then incubated with 1 μM 17β-E2 for 48 h; (v) LPS group, pre-treated with 100 ng/mL LPS for 24 h, then cells were washed by PBS for 3 times and incubated with 0.1% DMSO alone for 48 h; (vi) 17β-E2 plus LPS group, pre-treated with 100 ng/mL LPS for 24 h, then cells were washed by PBS for 3 times and incubated with 1 μM 17β-E2 for 48 h. The levels of triglyceride and adipose triglyceride lipase (ATGL) in differentiated 3T3-L1 cells and the concentrations of interleukin-6 (IL-6) in culture medium were measured.. Comparing with control group, 1 μM and 0.1 μM 17β-E2 decreased the intracellular TG levels by about 20% and 10% respectively (all P < 0.05). The triglyceride-lowing effect of 17β-E2 in differentiated 3T3-L1 cells was abolished by ERα antagonist MPP but not ERβ antagonist PHTPP. Comparing with control group, the IL-6 levels were significantly higher in the culture medium of the cultured differentiated 3T3-L1 cells in LPS group and 17β-E2 + LPS group (all P < 0.05). And, the IL-6 levels were similar in LPS group and 17β-E2 + LPS group (P > 0.05). There was no significant difference in the triglyceride contents of differentiated 3T3-L1 cells among control group, LPS group and 17β-E2 + LPS group (all P > 0.05). ATGL expression in 17β-E2 group was significantly higher than control group (P < 0.05), which was abolished by ERα antagonist MPP or LPS.. 17β-E2 increased ATGL expression and lowered triglycerides in adipocytes but not in LPS stimulated adipocytes via estrogen ERα.

Topics: 3T3-L1 Cells; Adipocytes; Animals; Cell Differentiation; Estradiol; Estrogen Antagonists; Estrogen Receptor alpha; Estrogen Receptor beta; Gene Expression Regulation; Inflammation; Interleukin-6; Lipase; Lipid Metabolism; Lipopolysaccharides; Mice; Piperidines; Pyrazoles; Pyrimidines; Triglycerides

Our previous studies showed that ethanol elicited estrogen (E2)-dependent myocardial oxidative stress and dysfunction. In the present study we tested the hypothesis that E2 signaling via the estrogen receptor (ER), ERα, mediates this myocardial detrimental effect of alcohol. To achieve this goal, conscious female rats in proestrus phase (highest endogenous E2 level) received a selective ER antagonist (200 μg/kg; intra-venous [i.v.]) for ERα (MPP), ERβ (PHTPP) or GPER (G15) or saline 30 min before ethanol (1 g/kg; i.v.) or saline infusion. ERα blockade virtually abrogated ethanol-evoked myocardial dysfunction and hypotension, while ERβ blockade had little effect on the hypotensive response, but caused delayed attenuation of the ethanol-evoked reductions in left ventricular developed pressure and the rate of left ventricle pressure rise. GPER blockade caused delayed attenuation of all cardiovascular effects of ethanol. All three antagonists attenuated the ethanol-evoked increases in myocardial catalase and ALDH2 activities, Akt, ERK1/2, p38, eNOS, and nNOS phosphorylation, except for a lack of effect of PHTPP on p38. Finally, all three ER antagonists attenuated ethanol-evoked elevation in myocardial ROS, but this effect was most notable with ERα blockade. In conclusion, ERα plays a greater role in, and might serve as a molecular target for ameliorating, the E2-dependent myocardial oxidative stress and dysfunction caused by ethanol.

Topics: Aldehyde Dehydrogenase; Animals; Benzodioxoles; Blood Pressure; Catalase; Consciousness; Estrogen Receptor alpha; Estrogen Receptor beta; Ethanol; Female; Myocardium; Nitrates; Nitrites; Oxidative Stress; Phosphorylation; Piperidines; Pyrazoles; Pyrimidines; Quinolines; Rats; Reactive Oxygen Species; Receptors, G-Protein-Coupled; Ventricular Function, Left

The net vascular effect of estrogens on the vasculature is still under debate. Here we tested the effects of estradiol- 17β (E2) as well as estrogen-receptor subtype specific and non-specific agonists and antagonists on the expression and eicosanoid production of lipoxygenase (LO) enzymes expressed in culture human umbilical vascular smooth muscle cells (VSMC), the platelet type 12LO and 15LO type 2. E2 increased 12 and 15LO mRNA expression by 2-3 folds and elicited an acute 50% increase 12 and 15 hydroxyeicosatetraenoic acid (HETE) production. Neither estrogen receptor ERα nor ERβ-specific agonists were able to reproduce the induction of LO expression, but E2-induced expression was effectively blocked by ER non-specific and receptor subtype specific antagonists. Because 12 and 15HETE can increase reactive oxygen species in other cell types, we tested the possibility that E2 could raise ROS through LO. Indeed, E2 as well as the LO products 12 and 15HETE increased reactive oxygen species (ROS) in VSMC. E2-dependent and HETE-induced ROS could be blocked by NAD (P) H-oxidase inhibitors and by the ER general antagonist ICI. E2-induced ROS was partially (∼50%) blocked by the LO inhibitor baicalein, but the LO blocker had no effect on 12 or 15HETE- induced ROS formation, thus suggesting that part of E2-dependent ROS generation resulted from E2-induced 12 and 15HETE. Collectively these findings unveil an unrecognized effect of E2 in human VSMC, to induce 12 and 15LO type 2 expression and activity and suggest that E2-dependent ROS formation in VSMC may be partially mediated by the induction of 12 and 15HETE.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Arachidonate 12-Lipoxygenase; Arachidonate 15-Lipoxygenase; Estradiol; Estrogen Receptor alpha; Estrogen Receptor beta; Flavanones; Gene Expression Regulation; Humans; Hydroxyeicosatetraenoic Acids; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; NADPH Oxidases; Nitriles; Phenols; Piperidines; Primary Cell Culture; Propionates; Pyrazoles; Pyrimidines; Raloxifene Hydrochloride; Reactive Oxygen Species; RNA, Messenger; Umbilical Veins

Estradiol (E2) perfusion rapidly increases the strength of fast excitatory transmission and facilitates long-term potentiation in the hippocampus, two effects likely related to its memory-enhancing properties. Past studies showed that E2's facilitation of transmission involves activation of RhoA signaling leading to actin polymerization in dendritic spines. Here we report that brief exposure of adult male hippocampal slices to 1 nM E2 increases the percentage of postsynaptic densities associated with high levels of immunoreactivity for activated forms of the BDNF receptor TrkB and β1-integrins, two synaptic receptors that engage actin regulatory RhoA signaling. The effects of E2 on baseline synaptic responses were unaffected by pretreatment with the TrkB-Fc scavenger for extracellular BDNF or TrkB antagonism, but were eliminated by neutralizing antisera for β1-integrins. E2 effects on synaptic responses were also absent in conditional β1-integrin knockouts, and with inhibition of matrix metalloproteinases, extracellular enzymes that generate integrin ligands. We propose that E2, acting through estrogen receptor-β, transactivates synaptic TrkB and β1-integrin, and via mechanisms dependent on integrin activation and signaling, reversibly reorganizes the spine cytoskeleton and thereby enhances synaptic responses in adult hippocampus.

Topics: Animals; Animals, Newborn; Benzodioxoles; Dipeptides; Disks Large Homolog 4 Protein; Estrogen Receptor Modulators; Estrogens; Excitatory Postsynaptic Potentials; Female; Gene Expression Regulation; Guanylate Kinases; Hippocampus; Integrin beta1; Integrins; Male; Matrix Metalloproteinase Inhibitors; Membrane Proteins; Mice, Knockout; Neurons; Phenylalanine; Piperidines; Pyrazoles; Pyrimidines; Quinolines; Rats; Rats, Sprague-Dawley; Receptors, Estrogen; Thiophenes

Accumulating evidence indicated protective role of phytoestrogens against neuronal damage induced by various insults, such as amyloid beta, oxygen deprivation and mitochondrial toxins. Hydrogen peroxide (H2 O2 ) influences the mitochondrial membrane potential, which eventually results in cell apoptosis. In this study, we investigated the effects and possible mechanisms of a phytoestrogen, pterostilbene (PTER), in cell apoptosis induced by H2 O2 in human neuronal SH-SY5Y cells. We also analysed the involvement of oestrogen receptors, oestrogen receptor-α and -β (ER-α and ER-β) in the protective role of PTER.. The effects of PTER on H2 O2 -stimulated cell were examined using MTT and FACS analysis. The signal pathways and estrogen receptors involved in PTER's effects were investigated using MTT and Western blot analysis.. The results showed that H2 O2 treatment significantly reduced cell viability in SY5Y cells, which was protected by PTER treatment. We also found that H2O2 inhibited the PI3K/AKT and MAPK/ERK signalling pathways, whereas PTER treatment restored these signalling pathways. We also found that the PTER effect could be largely blocked by an ER-α antagonist, 3-Bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy)phenol]-1H-pyrazole dihydrochloride (MPP), but not by an ER-β antagonist, 4-[2-Phenyl-5,7-bis(trifluoromethyl)pyrazolo[1,5-a] pyrimidin-3-yl]phenol (PHTPP), suggesting that ER-α is a major player in the neuroprotective activity of PTER.. Our study thus demonstrates that PTER is an effective neuroprotective agent presumably through ER-α-mediated signalling pathways.

Topics: Apoptosis; Cell Line, Tumor; Cell Survival; Estrogen Receptor alpha; Humans; Hydrogen Peroxide; Neuroprotective Agents; Oxidation-Reduction; Oxidative Stress; Piperidines; Pyrazoles; Pyrimidines; Signal Transduction; Stilbenes

Multiple lines of evidence suggest that the sex steroid hormone 17-β estradiol (E2) plays a protective role in schizophrenia. Systemic E2 enhances prepulse inhibition (PPI) of the acoustic startle reflex, an operational measure of sensorimotor gating known to be impaired in schizophrenia and related disorders. However, the relative contribution of different estrogen-receptor (ER) isoforms in these associations still awaits examination.. The present study explored the effects of ER-α and ER-β stimulation or blockade on PPI and their functional relevance in an amphetamine-induced PPI deficiency model in male mice.. Prior to the assessment of PPI, C57BL/6N male mice were injected with the ER-α agonist 4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol (PPT), the ER-α antagonist 1,3-bis (4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy) phenol]-1N-pyrozole dihydrochloride (MPP), the ER-β agonist 2,3-bis (4-hydroxyphenyl)-propionitrile (DPN), or the ER-β antagonist 4-[2-phenyl-5,7-bis (trifluoromethyl) pyrazolo [1,5-a] pyrimidin-3-yl] phenol (PHTPP), with or without concomitant amphetamine treatment.. Acute pharmacological stimulation and blockade of ER-α, respectively, led to a dose-dependent increase and decrease in basal PPI. In contrast, acute treatment with preferential ER-β modulators spared PPI under basal conditions. Pretreatment with either ER-α or ER-β agonist was, however, effective in blocking amphetamine-induced PPI disruption.. Our study demonstrates that activation of either ER isoform is capable of modulating dopamine-dependent PPI levels. At the same time, our results suggest that endogenous ER-α signaling may be more relevant than ER-β in the regulation of sensorimotor gating under basal conditions.

Topics: Animals; Estradiol; Estrogen Receptor Modulators; Male; Mice; Mice, Inbred C57BL; Nitriles; Phenols; Piperidines; Prepulse Inhibition; Pyrazoles; Pyrimidines; Signal Transduction

The high risk of knee injuries in female may be associated with sex-steroid hormone fluctuations during the menstrual cycle by its effect on ligaments and tendons stiffness. This study examined changes in knee range of motion in presence of estrogen and progesterone and investigated the interaction of their antagonists to relaxin receptors.. Sixty WKY rats were divided into 10 different groups receiving 17β-estradiol (0.2, 2, 20 and 50 μg/kg), progesterone (4 mg/kg), estrogen receptor (ER) antagonist ICI 182/780, ERβ antagonist PHTPP, ERα antagonist MPP, and mifepristone in presence of estrogen and progesterone. Physiologic dose were injected subcutaneously 30 min before of hormone injection for 3 days consequently. Sham group received peanut oil (vehicle) also for 3 consecutive days. Following the treatment administrations, the knee range of motion and RXFP1/RXFP2 mRNA and protein expression were examined in the patellar tendon, lateral collateral ligament, and hamstring muscle.. Our data showed that the knee range of motion was significantly increased in progesterone and high doses estrogen treatment but not significantly increased in low doses of estrogen treatment. The range of motion was decreased in the presence of estrogen receptor (ER) antagonist ICI 182/780, ERβ antagonist PHTPP, ERα antagonist MPP, and mifepristone, independently.. Progesterone and high doses of estrogen treatment resulted in the highest range of knee laxity correlated to expression of both relaxin receptor isoforms in knee tissues. Our findings thus suggested that female subjects are more vulnerable toward non-traumatic knee injury due to estrogen and progesterone fluctuation as compared to male subjects.

Topics: Animals; Estradiol; Female; Fulvestrant; Hindlimb; Male; Mifepristone; Piperidines; Progesterone; Pyrazoles; Pyrimidines; Range of Motion, Articular; Rats; Rats, Inbred WKY; Receptors, G-Protein-Coupled; Receptors, Peptide; Steroids

Topics: Animals; Cell Line; Diabetes Mellitus, Experimental; Diabetic Foot; Estrogen Receptor alpha; Estrogen Receptor Antagonists; Estrogen Receptor beta; Humans; Mice, Knockout; Piperidines; Pyrazoles; Pyrimidines; Wound Healing

The expression of arginine-vasopressin (AVP) is regulated by estradiol and testosterone (T) in different neuronal populations by mechanisms that are not yet fully understood. Estrogen receptors (ERs) have been shown to participate in the regulation of AVP neurons by estradiol. In addition, there is evidence of the participation of ERβ in the regulation of AVP expression exerted by T via its metabolite 5α-dihydrotestosterone (5α-DHT) and its further conversion in the androgen metabolite and ERβ ligand 3β-diol. In this study we have explored the role of ERs in the regulation exerted by estradiol and T on AVP expression, using the human neuroblastoma cell line SH-SY5Y. Estradiol treatment increased AVP mRNA levels in SH-SY5Y cells in comparison with cells treated with vehicle. The stimulatory effect of estradiol on AVP expression was imitated by the ERα agonist 4,4',4',-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol and blocked by the ER antagonist, ICI 182,780, and the ERα antagonist 1,3-bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy)phenol]-1hpyrazoledihydrochloride. In contrast, the ERβ agonist 2,3-bis(4-hydroxyphenyl)-propionitrile reduced AVP expression, whereas the ERβ antagonist 4-[2-phenyl-5,7-bis(trifluoromethyl) pyrazolo[1,5-a]pyrimidin-3-yl]phenol enhanced the action of estradiol on AVP expression. T increased AVP expression in SH-SY5Y cells by a mechanism that was dependent on aromatase but not on 5α-reductase activity. The T effect was not affected by blocking the androgen receptor, was not imitated by the T metabolite 5α-DHT, and was blocked by the ERα antagonist 1,3-bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy)phenol]-1hpyrazoledihydrochloride. In contrast, 5α-DHT had a similar effect as the ERβ agonists 2,3-bis(4-hydroxyphenyl)-propionitrile and 3β-diol, reducing AVP expression. These findings suggest that estradiol and T regulate AVP expression in SH-SY5Y cells through ERs, exerting a stimulatory action via ERα and an inhibitory action via ERβ.

Topics: Arginine Vasopressin; Cell Line, Tumor; Estradiol; Estrogen Receptor alpha; Estrogen Receptor beta; Female; Fulvestrant; Gene Expression Regulation, Neoplastic; Humans; Neuroblastoma; Nitriles; Phenols; Piperidines; Pyrazoles; Pyrimidines; Reverse Transcriptase Polymerase Chain Reaction; Testosterone

To investigate how mandibular and femoral growth is affected when sex hormone- specific receptor antagonist is administered in growing mice.. Forty C57BL/6J mice were used in this experiment. At 5 days of age, the mice received daily injection of estrogen receptor alpha (ERα), beta (ERβ), or androgen receptor (AR) antagonists, and their body weight was assessed every 4 days. One, four and eight weeks after the initial injection, radiographs of the mandible and femur were taken and measured. Analyses of variance and pairwise comparisons (Fisher) were performed to examine the differences in values measured among the groups.. Mandibular growth was affected by ERβ antagonist injection in male mice at 4 and 8 weeks. In female mice, the growth was affected during all the experimental period, when ERβ was administered. Moreover, at 8 weeks, mandibular growth was also affected in male and female mice injected with ERα antagonist and in male mice injected with AR antagonist. Femoral growth was affected during all the experimental period in male and female mice injected with ERβ antagonist. Moreover, at 8 weeks, the growth was affected in male and female mice injected with ERα antagonist and in male mice injected with AR antagonist.. Growth of the mandible and femur in mice, in part, is induced in response to the stimulation of ERβ in chondrocytes before and during early puberty. In late and after puberty, the growth is induced by the stimulation of ERα in male and female mice and that of AR in male mice.

Topics: Age Factors; Androgen Receptor Antagonists; Animals; Body Weight; Cephalometry; Epiphyses; Estrogen Receptor alpha; Estrogen Receptor beta; Female; Femur; Flutamide; Gonadal Steroid Hormones; Male; Mandible; Mandibular Condyle; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Microradiography; Piperidines; Pyrazoles; Pyrimidines; Time Factors

A variety of pharmacological agonists, antagonists and selective estrogen receptor modulators (SERM) have been used to better understand the role of specific receptors in various physiological processes. Despite similar structure and function, less is known about the effect of agonists and antagonists on teleost estrogen receptors and the results of these studies have indicated wide variation among species. The goal of this study was to determine the ability of two human SERMs to modulate activation of three zebrafish estrogen receptor isoforms. Full length cDNA of zebrafish estrogen receptor 1 (esr1), estrogen receptor 2a (esr2a) and estrogen receptor 2b (esr2b) were cloned into expression vectors and transfected into cells that do not endogenously express any estrogen receptor along with an estrogen responsive luciferase vector. Cells transfected with any of the zebrafish estrogen receptors individually and then exposed to 17β-estradiol (E₂) or 17α-ethinylestradiol (EE₂) exhibited a dose dependent increase in luciferase activity. None of the pharmacological antagonists, ICI 182, 780, methyl-piperidino-pyrazole (MPP) or pyrazolo [1,5-a] pyrimidine (PHTPP), were able to independently transactivate luciferase expression with any of the zebrafish estrogen receptors. Of the three ER antagonists, only ICI 182, 780 was able to block EE₂ induced luciferase activity, although a 10 to 100-fold excess of ICI 182, 780 was necessary with all receptors. Neither MPP nor PHTPP were able to block EE₂ induced luciferase activity with any isoform of zebrafish estrogen receptor. These results indicate that the difference between human ER and zebrafish ER ligand binding is not conserved enough for the SERMs MPP or PHTPP to elicit similar effects in zebrafish as those manifested in humans.

Topics: Animals; Cell Line, Tumor; Estradiol; Ethinyl Estradiol; Fulvestrant; Humans; Piperidines; Pyrazoles; Pyrimidines; Receptors, Estrogen; Selective Estrogen Receptor Modulators; Zebrafish

While there is considerable evidence that the ovarian hormone estradiol reduces food intake in female rats, it is unclear which estrogen receptor (ER) subtype, ERα or ERβ, mediates this effect. While several studies have demonstrated that activation of ERα, but not ERβ, is sufficient to reduce food intake in ovariectomized (OVX) rats, there are limited data regarding which receptor subtype is necessary. Here we used the selective ERα and ERß antagonists, MPrP and PHTPP, respectively, to investigate this question. We found that antagonism of ERα, but not ERβ, prevented the decrease in food intake following acute administration of estradiol in OVX rats. In addition, antagonism of ERα prevented the estrous-related, phasic reduction in food intake that occurs in response to the rise in circulating levels of estradiol in cycling rats. We conclude that activation of ERα is necessary for the anorexigenic effects of exogenous and endogenous estradiol in female rats.

Topics: Animals; Anorexia; Appetite Depressants; Drug Evaluation, Preclinical; Eating; Estradiol; Estrogen Receptor alpha; Female; Ovariectomy; Piperidines; Pyrazoles; Pyrimidines; Rats; Rats, Long-Evans; Selective Estrogen Receptor Modulators