Estrogen Receptor Beta and 2-arachidonoylglycerol Mediate the Suppressive Effects of Estradiol on Frequency of Postsynaptic Currents in Gonadotropin-Releasing Hormone Neurons of Metestrous Mice: An Acute Slice Electrophysiological Study.

Gonadotropin-releasing hormone (GnRH) neurons are controlled by 17beta-estradiol (E2) contributing to the steroid feedback regulation of the reproductive axis. In rodents, E2 exerts a negative feedback effect upon GnRH neurons throughout the estrus-diestrus phase of the ovarian cycle. The present study was undertaken to reveal the role of estrogen receptor subtypes in the mediation of the E2 signal and elucidate the downstream molecular machinery of suppression. The effect of E2 administration at low physiological concentration (10 pM) on GnRH neurons in acute brain slices obtained from metestrous GnRH-green fluorescent protein (GFP) mice was studied under paradigms of blocking or activating estrogen receptor subtypes and interfering with retrograde 2-arachidonoylglycerol (2-AG) signaling. Whole-cell patch clamp recordings revealed that E2 significantly diminished the frequency of spontaneous postsynaptic currents (sPSCs) in GnRH neurons (49.62 +/- 7.6%) which effect was abolished by application of the estrogen receptor (ER) alpha/beta blocker Faslodex (1 muM). Pretreatment of the brain slices with cannabinoid receptor type 1 (CB1) inverse agonist AM251 (1 muM) and intracellularly applied endocannabinoid synthesis blocker THL (10 muM) significantly attenuated the effect of E2 on the sPSCs. E2 remained effective in the presence of tetrodotoxin (TTX) indicating a direct action of E2 on GnRH cells. The ERbeta specific agonist DPN (10 pM) also significantly decreased the frequency of miniature postsynaptic currents (mPSCs) in GnRH neurons. In addition, the suppressive effect of E2 was completely blocked by the selective ERbeta antagonist PHTPP (1 muM) indicating that ERbeta is required for the observed rapid effect of the E2. In contrast, the ERalpha agonist PPT (10 pM) or the membrane-associated G protein-coupled estrogen receptor (GPR30) agonist G1 (10 pM) had no significant effect on the frequency of mPSCs in these neurons. AM251 and tetrahydrolipstatin (THL) significantly abolished the effect of E2 whereas AM251 eliminated the action of DPN on the mPSCs. These data suggest the involvement of the retrograde endocannabinoid mechanism in the rapid direct effect of E2. These results collectively indicate that estrogen receptor beta and 2-AG/CB1 signaling mechanisms are coupled and play an important role in the mediation of the negative estradiol feedback on GnRH neurons in acute slice preparation obtained from intact, metestrous mice

A juvenilis és felnőttkori dermatomyositises betegek klinikai jellemzői

Absztrakt Bevezetés: A juvenilis és felnőttkori dermatomyositisek szisztémás autoimmun megbetegedések, jellegzetességük a proximális végtagizomzat szimmetrikus gyengesége és típusos bőrtünetek megjelenése. Célkitűzés: A felnőttkori, illetve gyermekkori dermatomyositises betegek összehasonlítása tüneteik, laboratóriumi és immunszerológiai paramétereik, terápiára adott válaszuk, illetve kórlefolyásuk alapján. Módszer: A szerzők a vizsgálatban részt vevő betegek klinikai dokumentációinak retrospektív elemzésével összehasonlították a juvenilis és felnőttkori dermatomyositises betegcsoportokat a célkitűzésben megadott szempontok alapján. A kutatásba 27 juvenilis (átlagéletkor: 8,7 év, átlagos követési idő: 104,6 hónap) és 30 felnőttkori (átlagéletkor: 50,3, átlagos követési idő: 58,1 hónap) dermatomyositises beteget vontak be. Eredmények: A juvenilis dermatomyositises betegek között gyakrabban került sor cyclosporin A és intravénás immunglobulin alkalmazására. A felnőtt korú betegek között az akut betegségkezdet gyakrabban fordult elő. Gyermekekben a tünetek fokozatosan jelentkeznek. Következtetések: A szerzők eredményei egyeznek a szakirodalomban leírtakkal. Megfigyeléseik szerint a két alcsoport klinikailag és terápiás szempontból is különbözik. Betegeik rendszeres gondozása a remisszió elérése után is szükséges – elkerülve ezzel a rossz betegcompliance-t –, ezáltal csökkenthető a relapsusok száma és súlyossága. Orv. Hetil., 2015, 156(37), 1491–1496

Glucagon-Like Peptide-1 Excites Firing and Increases GABAergic Miniature Postsynaptic Currents (mPSCs) in Gonadotropin-Releasing Hormone (GnRH) Neurons of the Male Mice via Activation of Nitric Oxide (NO) and Suppression of Endocannabinoid Signaling Pathways

Glucagon-like peptide-1 (GLP-1), a metabolic signal molecule, regulates reproduction, although, the involved molecular mechanisms have not been elucidated, yet. Therefore, responsiveness of gonadotropin-releasing hormone (GnRH) neurons to the GLP-1 analog Exendin-4 and elucidation of molecular pathways acting downstream to the GLP-1 receptor (GLP-1R) have been challenged. Loose patch-clamp recordings revealed that Exendin-4 (100 nM-5 μM) elevated firing rate in hypothalamic GnRH-GFP neurons of male mice via activation of GLP-1R. Whole-cell patch-clamp measurements demonstrated increased excitatory GABAergic miniature postsynaptic currents (mPSCs) frequency after Exendin-4 administration, which was eliminated by the GLP-1R antagonist Exendin-3(9-39) (1 μM). Intracellular application of the G-protein inhibitor GDP-β-S (2 mM) impeded action of Exendin-4 on mPSCs, suggesting direct excitatory action of GLP-1 on GnRH neurons. Blockade of nitric-oxide (NO) synthesis by Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME; 100 μM) or N(5)-[Imino(propylamino)methyl]-L-ornithine hydrochloride (NPLA; 1 μM) or intracellular scavenging of NO by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (CPTIO; 1 mM) partially attenuated the excitatory effect of Exendin-4. Similar partial inhibition was achieved by hindering endocannabinoid pathway using cannabinoid receptor type-1 (CB1) inverse-agonist 1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-(1-piperidyl) pyrazole-3-carboxamide (AM251; 1 μM). Simultaneous blockade of NO and endocannabinoid signaling mechanisms eliminated action of Exendin-4 suggesting involvement of both retrograde machineries. Intracellular application of the transient receptor potential vanilloid 1 (TRPV1)-antagonist 2E-N-(2, 3-Dihydro-1,4-benzodioxin-6-yl)-3-[4-(1, 1-dimethylethyl)phenyl]-2-Propenamide (AMG9810; 10 μM) or the fatty acid amide hydrolase (FAAH)-inhibitor PF3845 (5 μM) impeded the GLP-1-triggered endocannabinoid pathway indicating an anandamide-TRPV1-sensitive control of 2-arachidonoylglycerol (2-AG) production. Furthermore, GLP-1 immunoreactive (IR) axons innervated GnRH neurons in the hypothalamus suggesting that GLP-1 of both peripheral and neuronal sources can modulate GnRH neurons. RT-qPCR study confirmed the expression of GLP-1R and neuronal NO synthase (nNOS) mRNAs in GnRH-GFP neurons. Immuno-electron microscopic analysis revealed the presence of nNOS protein in GnRH neurons. These results indicate that GLP-1 exerts direct facilitatory actions via GLP-1R on GnRH neurons and modulates NO and 2-AG retrograde signaling mechanisms that control the presynaptic excitatory GABAergic inputs to GnRH neurons

Elektromos járművek tárolásának és töltésének veszélyei épületekben = Dangers of storing and charging electric vehicles in buildings

The fire risk presented by all forms of vehicles is very high, yet in recent years the risk level has increased with the advent of electrically powered vehicles, due to charging methods and battery technology. How to assess the fire risk forms the content of this study and how to approach fire prevention technology, the risk of damage to structure and other material assets