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Frontiers in Neuroendocrinology Oct 2020Estradiol is the "prototypic" sex hormone of women. Yet, women have another sex hormone, which is often disregarded: Progesterone. The goal of this article is to provide... (Review)
Review
Estradiol is the "prototypic" sex hormone of women. Yet, women have another sex hormone, which is often disregarded: Progesterone. The goal of this article is to provide a comprehensive review on progesterone, and its metabolite allopregnanolone, emphasizing three key areas: biological properties, main functions, and effects on mood in women. Recent years of intensive research on progesterone and allopregnanolone have paved the way for new treatment of postpartum depression. However, treatment for premenstrual syndrome and premenstrual dysphoric disorder as well as contraception that women can use without risking mental health problems are still needed. As far as progesterone is concerned, we might be dealing with a two-edged sword: while its metabolite allopregnanolone has been proven useful for treatment of PPD, it may trigger negative symptoms in women with PMS and PMDD. Overall, our current knowledge on the beneficial and harmful effects of progesterone is limited and further research is imperative.
Topics: Emotions; Female; Humans; Pregnanolone; Premenstrual Dysphoric Disorder; Progesterone
PubMed: 32730861
DOI: 10.1016/j.yfrne.2020.100856 -
The Journal of Clinical Psychiatry Feb 2020
Review
Topics: Adult; Contraceptives, Oral, Hormonal; Evidence-Based Medicine; Female; Gonadotropin-Releasing Hormone; Humans; Pregnanolone; Premenstrual Dysphoric Disorder; Selective Serotonin Reuptake Inhibitors
PubMed: 32023366
DOI: 10.4088/JCP.19ac13071 -
Biological Psychiatry Feb 2022Brexanolone (allopregnanolone) was recently approved by the Food and Drug Administration for the treatment of postpartum depression, demonstrating long-lasting...
BACKGROUND
Brexanolone (allopregnanolone) was recently approved by the Food and Drug Administration for the treatment of postpartum depression, demonstrating long-lasting antidepressant effects. Despite our understanding of the mechanism of action of neurosteroids as positive allosteric modulators of GABA (gamma-aminobutyric acid A) receptors, we still do not fully understand how allopregnanolone exerts persistent antidepressant effects.
METHODS
We used electroencephalogram recordings in rats and humans along with local field potential, functional magnetic resonance imaging, and behavioral tests in mice to assess the impact of neurosteroids on network states in brain regions implicated in mood and used optogenetic manipulations to directly examine their relationship to behavioral states.
RESULTS
We demonstrated that allopregnanolone and synthetic neuroactive steroid analogs with molecular pharmacology similar to allopregnanolone (SGE-516 [tool compound] and zuranolone [SAGE-217, investigational compound]) modulate oscillations across species. We further demonstrated a critical role for interneurons in generating oscillations in the basolateral amygdala (BLA) and a role for δ-containing GABA receptors in mediating the ability of neurosteroids to modulate network and behavioral states. Allopregnanolone in the BLA enhances BLA high theta oscillations (6-12 Hz) through δ-containing GABA receptors, a mechanism distinct from other GABA positive allosteric modulators, such as benzodiazepines, and alters behavioral states. Treatment with the allopregnanolone analog SGE-516 protects mice from chronic stress-induced disruption of network and behavioral states, which is correlated with the modulation of theta oscillations in the BLA. Optogenetic manipulation of the network state influences the behavioral state after chronic unpredictable stress.
CONCLUSIONS
Our findings demonstrate a novel molecular and cellular mechanism mediating the well-established anxiolytic and antidepressant effects of neuroactive steroids.
Topics: Animals; Antidepressive Agents; Basolateral Nuclear Complex; Female; GABA Modulators; Mice; Pregnanolone; Rats; Receptors, GABA-A
PubMed: 34561029
DOI: 10.1016/j.biopsych.2021.07.017 -
British Journal of Pharmacology Oct 2021Neurosteroids influence neuronal function and have multiple promising clinical applications. Direct modulation of postsynaptic neurotransmitter receptors by...
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 Ca 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 Ca 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.
Topics: Animals; Glutamic Acid; HEK293 Cells; Humans; Neurosteroids; Pregnanolone; Rats; Sulfates
PubMed: 33988248
DOI: 10.1111/bph.15529 -
Neuroscience and Biobehavioral Reviews Jun 2023Endogenous neurosteroids and synthetic neuroactive steroids (NAS) are important targets for therapeutic development in neuropsychiatric disorders. These steroids... (Review)
Review
Endogenous neurosteroids and synthetic neuroactive steroids (NAS) are important targets for therapeutic development in neuropsychiatric disorders. These steroids modulate major signaling systems in the brain and intracellular processes including inflammation, cellular stress and autophagy. In this review, we describe studies performed using unnatural enantiomers of key neurosteroids, which are physiochemically identical to their natural counterparts except for rotation of polarized light. These studies led to insights in how NAS interact with receptors, ion channels and intracellular sites of action. Certain effects of NAS show high enantioselectivity, consistent with actions in chiral environments and likely direct interactions with signaling proteins. Other effects show no enantioselectivity and even reverse enantioselectivity. The spectrum of effects of NAS enantiomers raises the possibility that these agents, once considered only as tools for preclinical studies, have therapeutic potential that complements and in some cases may exceed their natural counterparts. Here we review studies of NAS enantiomers from the perspective of their potential development as novel neurotherapeutics.
Topics: Humans; Neurosteroids; Brain; Receptors, GABA-A
PubMed: 37085023
DOI: 10.1016/j.neubiorev.2023.105191 -
Nature Oct 2023Type A γ-aminobutyric acid receptors (GABARs) are the principal inhibitory receptors in the brain and the target of a wide range of clinical agents, including...
Type A γ-aminobutyric acid receptors (GABARs) are the principal inhibitory receptors in the brain and the target of a wide range of clinical agents, including anaesthetics, sedatives, hypnotics and antidepressants. However, our understanding of GABAR pharmacology has been hindered by the vast number of pentameric assemblies that can be derived from 19 different subunits and the lack of structural knowledge of clinically relevant receptors. Here, we isolate native murine GABAR assemblies containing the widely expressed α1 subunit and elucidate their structures in complex with drugs used to treat insomnia (zolpidem (ZOL) and flurazepam) and postpartum depression (the neurosteroid allopregnanolone (APG)). Using cryo-electron microscopy (cryo-EM) analysis and single-molecule photobleaching experiments, we uncover three major structural populations in the brain: the canonical α1β2γ2 receptor containing two α1 subunits, and two assemblies containing one α1 and either an α2 or α3 subunit, in which the single α1-containing receptors feature a more compact arrangement between the transmembrane and extracellular domains. Interestingly, APG is bound at the transmembrane α/β subunit interface, even when not added to the sample, revealing an important role for endogenous neurosteroids in modulating native GABARs. Together with structurally engaged lipids, neurosteroids produce global conformational changes throughout the receptor that modify the ion channel pore and the binding sites for GABA and insomnia medications. Our data reveal the major α1-containing GABAR assemblies, bound with endogenous neurosteroid, thus defining a structural landscape from which subtype-specific drugs can be developed.
Topics: Animals; Mice; Binding Sites; Cryoelectron Microscopy; Depression, Postpartum; Flurazepam; gamma-Aminobutyric Acid; Hypnotics and Sedatives; Ion Channel Gating; Neurosteroids; Photobleaching; Pregnanolone; Protein Conformation; Protein Subunits; Receptors, GABA-A; Sleep Initiation and Maintenance Disorders; Zolpidem
PubMed: 37730991
DOI: 10.1038/s41586-023-06556-w -
ACS Chemical Neuroscience May 2023Multiple molecular targets have been identified to mediate membrane-delimited and nongenomic effects of natural and synthetic steroids, but the influence of steroid...
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 GABA 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.
Topics: Rats; Animals; Pregnanolone; Receptors, N-Methyl-D-Aspartate; Zebrafish; Glutamic Acid; Esters; gamma-Aminobutyric Acid; Receptors, GABA-A
PubMed: 37126803
DOI: 10.1021/acschemneuro.3c00131 -
Revista de Neurologia May 2022Catamenial pattern epilepsy is defined as an increase in the frequency of seizures during a specific stage of the menstrual cycle compared to baseline. It has been... (Review)
Review
Catamenial pattern epilepsy is defined as an increase in the frequency of seizures during a specific stage of the menstrual cycle compared to baseline. It has been described that around a third of women with epilepsy have a catamenial pattern. The changes in the seizure pattern would be explained by the influence of catamenial fluctuations, of female gonadal hormones on neuronal excitability. Progesterone through its metabolite allopregnanolone plays a protective role by increasing GABAergic transmission; however, its effect on brain progesterone receptors can increase neuronal excitability. The effects of estrogens are complex, they tend to increase neuronal excitability, although their effects depend on their concentration and exposure time. Three catamenial patterns of seizure exacerbation have been proposed: the perimenstrual pattern, the periovulatory pattern, and the luteal pattern. The diagnostic approach is carried out through a systematic process of 4 steps: a) clinical history of the pattern of the menstrual cycle and epileptic seizures; b) diagnostic methods to characterize the menstrual cycle and the pattern of seizures; c) check diagnostic criteria; and d) categorize the catamenial pattern. The treatment options studied require a higher level of evidence, and there is no specific treatment. Optimization of conventional antiseizure treatment is recommended as the first therapeutic option. Other therapeutic options, such as non-hormonal and hormonal treatments, could be useful in case the first therapeutic option proves to be ineffective.
Topics: Epilepsy, Reflex; Female; Humans; Menstrual Cycle; Pregnanolone; Progesterone; Seizures
PubMed: 35484702
DOI: 10.33588/rn.7409.2022041 -
Pharmacology & Therapeutics Jun 2022Positive allosteric modulators of γ-aminobutyric acid-A (GABA) receptors or GABAkines have been widely used medicines for over 70 years for anxiety, epilepsy, sleep,... (Review)
Review
Positive allosteric modulators of γ-aminobutyric acid-A (GABA) receptors or GABAkines have been widely used medicines for over 70 years for anxiety, epilepsy, sleep, and other disorders. Traditional GABAkines like diazepam have safety and tolerability concerns that include sedation, motor-impairment, respiratory depression, tolerance and dependence. Multiple GABAkines have entered clinical development but the issue of side-effects has not been fully solved. The compounds that are presently being developed and commercialized include several neuroactive steroids (an allopregnanolone formulation (brexanolone), an allopregnanolone prodrug (LYT-300), Sage-324, zuranolone, and ganaxolone), the α2/3-preferring GABAkine, KRM-II-81, and the α2/3/5-preferring GABAkine PF-06372865 (darigabat). The neuroactive steroids are in clinical development for post-partum depression, intractable epilepsy, tremor, status epilepticus, and genetic epilepsy disorders. Darigabat is in development for epilepsy and anxiety. The imidazodiazepine, KRM-II-81 is efficacious in animal models for the treatment of epilepsy and post-traumatic epilepsy, acute and chronic pain, as well as anxiety and depression. The efficacy of KRM-II-81 in models of pharmacoresistant epilepsy, preventing the development of seizure sensitization, and in brain tissue of intractable epileptic patients bodes well for improved therapeutics. Medicinal chemistry efforts are also ongoing to identify novel and improved GABAkines. The data document gaps in our understanding of the molecular pharmacology of GABAkines that drive differential pharmacological profiles, but emphasize advancements in the ability to successfully utilize GABA receptor potentiation for therapeutic gain in neurology and psychiatry.
Topics: Animals; Anticonvulsants; Epilepsy; Humans; Neurosteroids; Pregnanolone; Receptors, GABA-A; gamma-Aminobutyric Acid
PubMed: 34793859
DOI: 10.1016/j.pharmthera.2021.108035