The central nervous system is a well-known steroidogenic tissue producing, among others, cholesterol metabolites such as neuroactive steroids, oxysterols and steroid hormones. It is well known that these endogenous molecules affect several receptor classes, including ionotropic GABAergic and NMDA glutamatergic receptors in neurons. It has been shown that also ionotropic purinergic (P2X) receptors are cholesterol metabolites' targets. Among P2X receptors, purinergic P2X4 and P2X7 receptors are expressed in microglia, the innate immune cells involved in the brain inflammatory response. In this study, we explore the ionotropic purinergic receptors modulation by cholesterol metabolites in microglia. Patch-clamp experiments were performed in BV2 cells, a murine microglia cell line, to evaluate effects of cholesterol metabolites using micro- and nanomolar concentrations. About P2X4 receptor, we found that testosterone butyrate (20 μM and 200 nM) and allopregnanolone (10 μM and 100 nM) both potentiated its current, while neither 25-hydroxycholesterol (10 μM and 100 nM) nor 17β-estradiol (1 μM) showed any effects. On the other hand, P2X7 receptor current was potentiated by allopregnanolone (10 μM) and 25-hydroxycholesterol (10 μM and 100 nM). Taken together, our data show that modulation of either P2X4 and P2X7 current is affected differently by cholesterol metabolites, suggesting a structure-activity relationship among these players. Identifying the possible link between purinergic transmission, microglia and cholesterol metabolites will allow to define new targets for drug development to treat neuroinflammation.
- Klíčová slova
- Microglia, Neuroactive steroids, Neuroinflammation, Oxysterols, P2X4 receptor, P2X7 receptor,
- MeSH
- buněčné linie MeSH
- mikroglie * metabolismus MeSH
- pregnanolon * metabolismus MeSH
- purinergní receptory P2X4 * metabolismus MeSH
- testosteron * metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- pregnanolon * MeSH
- purinergní receptory P2X4 * MeSH
- testosteron * MeSH
Multiple molecular targets have been identified to mediate membrane-delimited and nongenomic effects of natural and synthetic steroids, but the influence of steroid metabolism on neuroactive steroid signaling is not well understood. To begin to address this question, we set out to identify major metabolites of a neuroprotective synthetic steroid 20-oxo-5β-pregnan-3α-yl l-glutamyl 1-ester (pregnanolone glutamate, PAG) and characterize their effects on GABAA and NMDA receptors (GABARs, NMDARs) and their influence on zebrafish behavior. Gas chromatography-mass spectrometry was used to assess concentrations of PAG and its metabolites in the hippocampal tissue of juvenile rats following intraperitoneal PAG injection. PAG is metabolized in the peripheral organs and nervous tissue to 20-oxo-17α-hydroxy-5β-pregnan-3α-yl l-glutamyl 1-ester (17-hydroxypregnanolone glutamate, 17-OH-PAG), 3α-hydroxy-5β-pregnan-20-one (pregnanolone, PA), and 3α,17α-dihydroxy-5β-pregnan-20-one (17-hydroxypregnanolone, 17-OH-PA). Patch-clamp electrophysiology experiments in cultured hippocampal neurons demonstrate that PA and 17-OH-PA are potent positive modulators of GABARs, while PAG and 17-OH-PA have a moderate inhibitory effect at NMDARs. PAG, 17-OH-PA, and PA diminished the locomotor activity of zebrafish larvae in a dose-dependent manner. Our results show that PAG and its metabolites are potent modulators of neurotransmitter receptors with behavioral consequences and indicate that neurosteroid-based ligands may have therapeutic potential.
- Klíčová slova
- glutamate, negative allosteric modulator, steroid, thigmotaxis, zebrafish,
- MeSH
- dánio pruhované MeSH
- estery MeSH
- GABA MeSH
- krysa rodu Rattus MeSH
- kyselina glutamová MeSH
- pregnanolon * farmakologie chemie MeSH
- receptory GABA-A MeSH
- receptory N-methyl-D-aspartátu * MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- estery MeSH
- GABA MeSH
- kyselina glutamová MeSH
- pregnanolon * MeSH
- receptory GABA-A MeSH
- receptory N-methyl-D-aspartátu * MeSH
BACKGROUND: Neurosteroids are investigated as effective antidotes for the poisoning induced by tetramethylenedisulfotetramine (TMDT) as well as treatments for epileptic spasms during infancy. Both these conditions are quite resistant to pharmacotherapy; thus, a search for new treatments is warranted. METHODS: In this study, we determined the efficacy of two novel neurosteroids, pregnanolone glutamate (PAG) and pregnanolone pyroglutamate (PPG), and tested these drugs in doses of 1-10 mg/kg (ip) against the TMDT syndrome and in our rodent model of infantile spasms. RESULTS: Only PPG in doses 5 and 10 mg/kg suppressed the severity of the TMDT syndrome and TMDT-induced lethality, while the 1 mg/kg dose was without an effect. Interestingly, the 1 mg/kg dose of PPG in combination with 1 mg/kg of diazepam was also effective against TMDT poisoning. Neither PAG nor PPG were effective against experimental spasms in the N-methyl-D-aspartate (NMDA)-triggered model of infantile spasms. CONCLUSIONS: While evidence suggests that PAG can act through multiple actions which include allosteric inhibition of NMDA-induced and glycine receptor-evoked currents as well as augmentation of ɣ-aminobutyric acid subtype A (GABAA) receptor-induced currents, the agent appears to neither have the appropriate mechanistic signature for activity in the infantile spasm model, nor the adequate potency, relative to PPG, for ameliorating the TMDT syndrome. The full mechanisms of action of PPG, which may become a potent TMDT antidote either alone or in combination with diazepam are yet unknown and thus require further investigation.
- Klíčová slova
- Antidote, Neurosteroids, Neurotoxicity, Severe seizures, Tetramethylenedisulfotetramine,
- MeSH
- diazepam farmakologie MeSH
- hlodavci MeSH
- křeče u dětí * chemicky indukované farmakoterapie MeSH
- kyselina glutamová MeSH
- kyselina pyrrolidonkarboxylová MeSH
- N-methylaspartát toxicita terapeutické užití MeSH
- neurosteroidy * MeSH
- neurotoxické syndromy * MeSH
- pregnanolon škodlivé účinky MeSH
- spasmus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- diazepam MeSH
- kyselina glutamová MeSH
- kyselina pyrrolidonkarboxylová MeSH
- N-methylaspartát MeSH
- neurosteroidy * MeSH
- pregnanolon MeSH
- tetramethylenedisulfotetramine MeSH Prohlížeč
Pregnancy and postpartum period are associated with demanding physical and psychological changes that often lead to the development of psychological disorders. Depression is diagnosed in more than one in six women after childbirth. However, the prevalence of postpartum depression can be much higher because many cases are undiagnosed. In the case of severe depression, the patient is switched to pharmacological treatment, with sertraline being the most commonly used for this diagnosis. A new drug used in the treatment of postpartum depression is brexanolone, which was registered by FDA in 2019. The advantage over conventional therapy is its rapid onset of action. The structure represents the neuroactive steroid - allopregnanolone, which acts as an agonist on the δ-subunit of the GABA receptor and improves the symptoms of postpartum depression. In addition to the registered brexanolone, another steroidal drug, zuranolone, is available in the third phase of the clinical trial. The steroid structure was chemically altered to improve bioavailability and create an oral dosage form. Another synthetic analogue of neuroactive allopregnanolone, known as ganaxolone, did not show a significant reduction in depressive symptoms in the second phase of the clinical trial compared to placebo. Nevertheless, it has great therapeutic potential in the treatment of various types of epilepsy.
- Klíčová slova
- allopregnanolone, brexanolone, ganaxolone, postpartum depression, zuranolone,
- MeSH
- lidé MeSH
- neurosteroidy * terapeutické užití MeSH
- poporodní deprese * farmakoterapie MeSH
- pregnanolon terapeutické užití MeSH
- receptory GABA terapeutické užití MeSH
- sertralin terapeutické užití MeSH
- těhotenství MeSH
- Check Tag
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- neurosteroidy * MeSH
- pregnanolon MeSH
- receptory GABA MeSH
- sertralin MeSH
The ability of endogenous neurosteroids (NSs) with pregnane skeleton modified at positions C-3 and C-5 to modulate the functional activity of inhibitory glycine receptors (GlyR) and ionotropic ɣ-aminobutyric acid receptors (GABAA R) was estimated. The glycine and GABA-induced chloride current (IGly and IGABA ) were measured in isolated pyramidal neurons of the rat hippocampus and in isolated rat cerebellar Purkinje cells, respectively. Our experiments demonstrated that pregnane NSs affected IGABA and IGly in a different manner. At low concentrations (up to 5 μM), tested pregnane NSs increased or did not change the peak amplitude of the IGABA , but reduced the IGly by decreasing the peak amplitude and/or accelerating desensitization. Namely, allopregnanolone (ALLO), epipregnanolone (EPI), pregnanolone (PA), pregnanolone sulfate (PAS) and 5β-dihydroprogesterone (5β-DHP) enhanced the IGABA in Purkinje cells. Dose-response curves plotted in the concentration range from 1 nM to 100 μM were smooth for EPI and 5β-DHP, but bell-shaped for ALLO, PA and PAS. The peak amplitude of the IGly was reduced by PA, PAS, and 5α- and 5β-DHP. In contrast, ALLO, ISO and EPI did not modulate it. Dose-response curves for the inhibition of the IGly peak amplitude were smooth for all active compounds. All NSs accelerated desensitization of the IGly . The dose-response relationship for this effect was smooth for ALLO, PA, PAS and 5β-DHP, but it was U-shaped for EPI, 5α-DHP and ISO. These results, together with our previous results on NSs with androstane skeleton, offer comprehensive overview for understanding the mechanisms of effects of NSs on IGly and IGABA .
- Klíčová slova
- GABAA receptor, glycine receptor, neurosteroid, pregnane, structure-activity relationship study,
- MeSH
- 5alfa-dihydroprogesteron farmakologie MeSH
- chloridy farmakologie MeSH
- GABA MeSH
- glycin farmakologie MeSH
- krysa rodu Rattus MeSH
- neurony fyziologie MeSH
- neurosteroidy * MeSH
- potkani Wistar MeSH
- pregnanolon * farmakologie MeSH
- pregnany farmakologie MeSH
- receptory GABA-A fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- 5alfa-dihydroprogesteron MeSH
- chloridy MeSH
- GABA MeSH
- glycin MeSH
- neurosteroidy * MeSH
- pregnanolon * MeSH
- pregnany MeSH
- receptory GABA-A MeSH
BACKGROUND AND PURPOSE: Neurosteroids influence neuronal function and have multiple promising clinical applications. Direct modulation of postsynaptic neurotransmitter receptors by neurosteroids is well characterized, but presynaptic effects remain poorly understood. Here, we report presynaptic glutamate release potentiation by neurosteroids pregnanolone and pregnanolone sulfate and compare their mechanisms of action to phorbol 12,13-dibutyrate (PDBu), a mimic of the second messenger DAG. EXPERIMENTAL APPROACH: We use whole-cell patch-clamp electrophysiology and pharmacology in rat hippocampal microisland cultures and total internal reflection fluorescence (TIRF) microscopy in HEK293 cells expressing GFP-tagged vesicle priming protein Munc13-1, to explore the mechanisms of neurosteroid presynaptic modulation. KEY RESULTS: Pregnanolone sulfate and pregnanolone potentiate glutamate release downstream of presynaptic Ca2+ influx, resembling the action of a phorbol ester PDBu. PDBu partially occludes the effect of pregnanolone, but not of pregnanolone sulfate. Calphostin C, an inhibitor that disrupts DAG binding to its targets, reduces the effect PDBu and pregnanolone, but not of pregnanolone sulfate, suggesting that pregnanolone might interact with a well-known DAG/phorbol ester target Munc13-1. However, TIRF microscopy experiments found no evidence of pregnanolone-induced membrane translocation of GFP-tagged Munc13-1, suggesting that pregnanolone may regulate Munc13-1 indirectly or interact with other DAG targets. CONCLUSION AND IMPLICATIONS: We describe a novel presynaptic effect of neurosteroids pregnanolone and pregnanolone sulfate to potentiate glutamate release downstream of presynaptic Ca2+ influx. The mechanism of action of pregnanolone, but not of pregnanolone sulfate, partly overlaps with that of PDBu. Presynaptic effects of neurosteroids may contribute to their therapeutic potential in the treatment of disorders of the glutamate system.
- Klíčová slova
- Munc13-1, glutamate, neurosteroid, phorbol ester, pregnanolone, presynaptic,
- MeSH
- HEK293 buňky MeSH
- krysa rodu Rattus MeSH
- kyselina glutamová MeSH
- lidé MeSH
- neurosteroidy * MeSH
- pregnanolon * farmakologie MeSH
- sírany MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- kyselina glutamová MeSH
- neurosteroidy * MeSH
- pregnanolon * MeSH
- sírany MeSH
Epipregnanolone (3β-hydroxy-5β-pregnan-20-one, Epi) is an endogenous steroid with important physiological effects and high affinity for GABAA receptors. The effect of Epi on GABA-induced chloride current (IGABA) in native neurons has hardly been studied. In this work, we studied the influence of Epi on the IGABA in the Purkinje cells of rat cerebellum and pyramidal neurons of rat hippocampus with the patch clamp technique. We showed that Epi is a positive modulator of the IGABA with EC50 of 5.7 µM in Purkinje cells and 9.3 µM in hippocampal neurons. Epi-induced potentiation of the IGABA was more potent at low vs. high GABA concentrations. Isopregnanolone (3β-hydroxy-5α-pregnan-20-one, Iso) counteracted Epi, reducing its potentiating effect by 2-2.3 times. Flumazenil, a nonsteroidal GABAA receptor antagonist, does not affect the Epi-induced potentiation. Comparison of the potentiating effects of Epi and allopregnanolone (3α-hydroxy-5α-pregnan-20-one, ALLO) showed that ALLO is, at least, a four times more potent positive modulator than Epi. The combined application of ALLO and Epi showed that the effects of these two steroids are not additive. We conclude that Epi has a dual effect on the IGABA increasing the current in the control solution and decreasing the stimulatory effect of ALLO.
- Klíčová slova
- GABA receptor, allopregnanolone, epipregnanolone, flumazenil patch clamp, isopregnanolone,
- MeSH
- agonisté receptorů GABA-A farmakologie MeSH
- hipokampus metabolismus MeSH
- krysa rodu Rattus MeSH
- mozeček metabolismus MeSH
- potkani Wistar MeSH
- pregnanolon farmakologie MeSH
- pyramidové buňky metabolismus MeSH
- receptory GABA-A metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- agonisté receptorů GABA-A MeSH
- pregnanolon MeSH
- receptory GABA-A MeSH
Neuroactive steroid 20-oxo-5β-pregnan-3α-yl L-glutamyl 1-ester (PA-Glu), a synthetic analogue of naturally occurring 20-oxo-5β-pregnan-3α-yl sulfate (pregnanolone sulfate, PA-S), inhibits N-methyl-D-aspartate (NMDA) receptors and possesses neuroprotective properties and minimal adverse effects. Herein, we report in vivo effects of new structural modifications of the PA-S molecule: a nonpolar modification of the steroid D-ring (5β-androstan-3α-yl L-glutamyl 1-ester, AND-Glu), attachment of a positively charged group to C3 (20-oxo-5β-pregnan-3α-yl L-argininate dihydrochloride salt, PA-Arg) and their combination (5β-androstan-3α-yl L-argininate dihydrochloride salt, AND-Arg). The first aim of this study was to determine the structure-activity relationship for neuroprotective effects in a model of excitotoxic hippocampal damage in rats, based on its behavioral correlate in Carousel maze. The second aim was to explore side effects of neuroprotective steroids on motor functions, anxiety (elevated plus maze) and locomotor activity (open field) and the effect of their high doses in mice. The neuroprotective properties of PA-Glu and AND-Glu were proven, with the effect of the latter appearing to be more pronounced. In contrast, neuroprotective efficacy failed when positively charged molecules (PA-Arg, AND-Arg) were used. AND-Glu and PA-Glu at the neuroprotective dose (1 mg/kg) did not unfavorably influence motor functions of intact mice. Moreover, anxiolytic effects of AND-Glu and PA-Glu were ascertained. These findings corroborate the value of research of steroidal inhibitors of NMDA receptors as potential neuroprotectants with slight anxiolytic effect and devoid of behavioral adverse effects. Taken together, the results suggest the benefit of the nonpolar D-ring modification, but not of the attachment of a positively charged group to C3.
- Klíčová slova
- Behavior, Cognitive functions, Excitotoxicity, NMDA receptor, Neuroactive steroid, Neuroprotection,
- MeSH
- agonisté excitačních aminokyselin toxicita MeSH
- antagonisté excitačních aminokyselin chemická syntéza farmakologie MeSH
- bludiště - učení účinky léků MeSH
- chování zvířat účinky léků MeSH
- hipokampus účinky léků metabolismus patologie patofyziologie MeSH
- lokomoce účinky léků MeSH
- molekulární struktura MeSH
- myši MeSH
- N-methylaspartát toxicita MeSH
- neuroprotektivní látky chemická syntéza farmakologie MeSH
- pohybová aktivita účinky léků MeSH
- potkani Long-Evans MeSH
- pregnanolon analogy a deriváty chemická syntéza farmakologie MeSH
- receptory N-methyl-D-aspartátu antagonisté a inhibitory metabolismus MeSH
- sírany chemická syntéza farmakologie MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- agonisté excitačních aminokyselin MeSH
- antagonisté excitačních aminokyselin MeSH
- N-methylaspartát MeSH
- neuroprotektivní látky MeSH
- pregnanolon MeSH
- receptory N-methyl-D-aspartátu MeSH
- sírany MeSH
The ability of pregnanolone glutamate (PA-Glu), pregnanolone hemisuccinate (PA-hSuc) and pregnanolone hemipimelate (PA-hPim), neuroactive steroids with a negative modulatory effect on excitatory N-methyl-d-aspartate receptors, to influence the functional activity of inhibitory γ-aminobutyric acid and glycine receptors was estimated. The GABA- and glycine-induced chloride currents (IGABA and IGly) were measured in isolated pyramidal neurons of the rat hippocampus using the patch-clamp technique. Compound PA-Glu was found to potentiate IGABA and to inhibit IGly, while PA-hSuc and PA-hPim inhibited both IGABA and IGly. Moreover, PA-Glu, PA-hSuc, and PA-hPim had a greater effect on desensitization than on the peak amplitude of IGly. At a high concentration of glycine (500 μM), the effect of neurosteroids on the peak amplitude of IGly disappeared, and the acceleration of desensitization remained. The conversion of PA-Glu into androstane glutamate (AND-Glu), an analogue that lacks the C-17 acetyl moiety, completely eliminated the effects on these receptors. Our results indicate that the C-17 acetyl moiety is crucial for the action on IGABA and IGly. Our results indicate that the pregnanolone derivatives, in contrast to the androstane analogues, modulate IGABA and IGly at low micromolar concentrations and this family of neurosteroids can be useful for future structure-activity relationship studies of the steroid modulation of other receptor types.
- Klíčová slova
- GABA receptor, Glycine receptor, Neurosteroid, Pregnanolone, Structure-activity relationship,
- MeSH
- hipokampus účinky léků fyziologie MeSH
- krysa rodu Rattus MeSH
- neurony účinky léků fyziologie MeSH
- neurotransmiterové látky chemie farmakologie MeSH
- orgánové kultury - kultivační techniky MeSH
- potkani Wistar MeSH
- pregnanolon chemie farmakologie MeSH
- pyramidové buňky MeSH
- receptory GABA-A fyziologie MeSH
- receptory glycinu fyziologie MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- neurotransmiterové látky MeSH
- pregnanolon MeSH
- receptory GABA-A MeSH
- receptory glycinu MeSH
A unique asymmetric total synthesis of the unnatural enantiomer of pregnanolone, as well as a study of its biological activity at the NMDA receptor, is reported. The asymmetry is introduced by a highly atom-economic organocatalytic Robinson annulation. A new method for the construction of the cyclopentane D-ring consisting of CuI-catalyzed conjugate addition and oxygenation followed by thermal cyclization employing the persistent radical effect was developed. ent-Pregnanolone sulfate is surprisingly only 2.6-fold less active than the natural neurosteroid.
