BACKGROUND: Monoamine oxidase (MAO) inhibitors can interact with selective serotonin reuptake inhibitors (SSRIs)/serotonin-norepinephrine reuptake inhibitors (SNRIs). There is clinical interest surrounding use of ozanimod with SSRIs/SNRIs because the major metabolites of ozanimod are weak inhibitors of MAO-B in vitro. OBJECTIVE: To evaluate the incidence of treatment-emergent adverse events (TEAEs) potentially related to serotonin accumulation (SA) during concomitant ozanimod and SSRI/SNRI use by performing analyses of data from an open-label, oral ozanimod 0.92 mg trial (DAYBREAK; NCT02576717). METHODS: SA narrow (serotonin syndrome, neuroleptic malignant syndrome, and hyperthermia malignant) and broad (terms potentially associated with SA) MedDRA v24.0 searches were performed using TEAE data from participants with relapsing multiple sclerosis who entered DAYBREAK from phase 3 studies (cutoff February 1, 2022). Incidences of TEAEs matching terms from each search were stratified by SSRI/SNRI use. RESULTS: Of 2257 DAYBREAK participants, 274 (12.1%) used an SSRI/SNRI. No participants had TEAEs matching the SA narrow search terms. There was no significant difference in the percentage of participants with ⩾1 TEAE matching the SA broad search for those on versus off SSRIs/SNRIs (on: 12.4%, n = 34/274; off: 15.6%, n = 310/1982, nominal p = 0.1630). CONCLUSION: MedDRA searches showed no increase in TEAEs potentially associated with SA with concomitant SSRI/SNRI and ozanimod use.
- MeSH
- antidepresiva škodlivé účinky MeSH
- indany * MeSH
- inhibitory zpětného vychytávání serotoninu a noradrenalinu * škodlivé účinky MeSH
- lidé MeSH
- oxadiazoly * MeSH
- roztroušená skleróza * chemicky indukované MeSH
- selektivní inhibitory zpětného vychytávání serotoninu škodlivé účinky MeSH
- serotonin MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Proper fetal development requires tight regulation of serotonin concentrations within the fetoplacental unit. This homeostasis is partly maintained by the placental transporter OCT3/SLC22A3, which takes up serotonin from the fetal circulation. Metformin, an antidiabetic drug commonly used to treat gestational diabetes mellitus, was shown to inhibit OCT3. We, therefore, hypothesized that its use during pregnancy could disrupt placental serotonin homeostasis. This hypothesis was tested using three experimental model systems: primary trophoblast cells isolated from the human term placenta, fresh villous human term placenta fragments, and rat term placenta perfusions. Inhibition of serotonin transport by metformin at three concentrations (1 μM, 10 μM, and 100 μM) was assessed in all three models. The OCT3 inhibitor decynium-22 (100 μM) and paroxetine (100 μM), a dual inhibitor of SERT and OCT3, were used as controls. In primary trophoblasts, paroxetine exhibited the strongest inhibition of serotonin uptake, followed by decynium-22. Metformin showed a concentration-dependent effect, reducing serotonin uptake by up to 57 % at the highest concentration. Its inhibitory effect was less pronounced in fresh villous fragments but remained statistically significant at all concentrations. In the perfused rat placenta, metformin demonstrated a concentration-dependent effect, reducing placental serotonin uptake by 44 % at the highest concentration tested. Our findings across all experimental models show inhibition of placental OCT3 by metformin, resulting in reduced serotonin uptake by the trophoblast. This sheds light on mechanisms that may underpin metformin-mediated effects on fetal development.
- MeSH
- biologický transport účinky léků MeSH
- hypoglykemika farmakologie MeSH
- krysa rodu rattus MeSH
- kultivované buňky MeSH
- lidé MeSH
- metformin * farmakologie MeSH
- oktamerní transkripční faktor 3 metabolismus MeSH
- placenta * metabolismus účinky léků MeSH
- potkani Wistar MeSH
- proteiny přenášející organické kationty MeSH
- serotonin * metabolismus MeSH
- těhotenství MeSH
- trofoblasty * metabolismus účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The increasing use of cannabis during pregnancy raises concerns about its impact on fetal development. While cannabidiol (CBD) shows therapeutic promise, its effects during pregnancy remain uncertain. We investigated CBD's influence on tryptophan (TRP) metabolism in the human placenta. TRP is an essential amino acid that is metabolized via the serotonin and kynurenine (KYN) pathways, which are critical for fetal neurodevelopment. We used human term villous placental explants, an advanced ex vivo model, to study CBD's impact on key TRP metabolic enzymes. In addition, vesicles isolated from the microvillous membrane (MVM) of the human placenta were used to assess CBD's effect on placental serotonin uptake. Explants were exposed to CBD at therapeutic (0.1, 1, 2.5 μg/ml) and non-therapeutic (20 and 40 μg/ml) concentrations to determine its effects on the gene and protein expression of key enzymes in TRP metabolism and metabolite release. CBD upregulated TRP hydroxylase (TPH) and downregulated monoamine oxidase (MAO-A), resulting in reduced levels of 5-hydroxyindoleacetic acid (HIAA). It also downregulated serotonin transporter expression and inhibited serotonin transport across the MVM by up to 60% while simultaneously enhancing TRP metabolism via the kynurenine pathway by upregulating indoleamine-pyrrole 2,3-dioxygenase (IDO-1). Among kynurenine pathway enzymes, kynurenine 3 monooxygenase (KMO) was upregulated while kynurenine aminotransferase 1 (KAT-1) was downregulated; the former is associated with neurotoxic metabolite production, while the latter is linked to reduced neuroprotective metabolite levels. Overall, these results indicate that CBD modulates TRP catabolism in the human placenta, potentially disrupting the tightly regulated homeostasis of the serotonin and KYN pathways.
Maternal immune activation during pregnancy is a risk factor for offspring neuropsychiatric disorders. Among the mechanistic pathways by which maternal inflammation can affect fetal brain development and programming, those involving tryptophan (TRP) metabolism have drawn attention because various TRP metabolites have neuroactive properties. This study evaluates the effect of bacterial (lipopolysaccharides/LPS) and viral (polyinosinic:polycytidylic acid/poly I:C) placental infection on TRP metabolism using an ex vivo model. Human placenta explants were exposed to LPS or poly I:C, and the release of TRP metabolites was analyzed together with the expression of related genes and proteins and the functional activity of key enzymes in TRP metabolism. The rate-limiting enzyme in the serotonin pathway, tryptophan hydroxylase, showed reduced expression and functional activity in explants exposed to LPS or poly I:C. Conversely, the rate-limiting enzyme in the kynurenine pathway, indoleamine dioxygenase, exhibited increased activity, gene, and protein expression, suggesting that placental infection mainly promotes TRP metabolism via the kynurenine (KYN) pathway. Furthermore, we observed that treatment with LPS or poly I:C increased activity in the kynurenine monooxygenase branch of the KYN pathway. We conclude that placental infection impairs TRP homeostasis, resulting in decreased production of serotonin and an imbalance in the ratio between quinolinic acid and kynurenic acid. This disrupted homeostasis may eventually expose the fetus to suboptimal/toxic levels of neuroactive molecules and impair fetal brain development.
- MeSH
- indolamin-2,3,-dioxygenasa metabolismus MeSH
- kynurenin * metabolismus MeSH
- lidé MeSH
- lipopolysacharidy toxicita MeSH
- placenta * metabolismus MeSH
- poly I metabolismus MeSH
- serotonin metabolismus MeSH
- těhotenství MeSH
- tryptofan metabolismus MeSH
- Check Tag
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Asthma poses an increased risk for cardiovascular disorders, suggesting that allergy, which is an underlying process in asthma, causes atypical functioning of organs other than lungs. In a previous study in a guinea pig asthma model, we concluded that allergic sensitization increased aorta contractile responses to 5-HT. To further characterize these responses, here we explored the role of the 5-HT2 receptors family. We found that TCB-2 (5-HT2A agonist) and WAY161503 (5-HT2C agonist) induced aorta contractions resembling those elicited by 5-HT but less intense (~43 % and ~25 %, respectively). In these experiments, aortas from sensitized guinea pigs showed increased contractions to TCB-2, but not to WAY161503. In turn, MDL 100907 (5-HT2A antagonist) and RS-102221 (5-HT2C antagonist) caused a notably and a mild reduction of the 5-HT-induced contractions, respectively, with no differences seen between sensitized and non-sensitized tissues. BW723C86 (5-HT2B agonist) did not induce contractile responses and RS-127445 (5-HT2B antagonist) did not modify the contractile responses to 5-HT. In non-sensitized aortas, the pattern of protein expression of receptors was 5HT2B>5-HT2A=5-HT2C, which did not change in sensitized animals. In conclusion, we found that allergic sensitization increased the aorta contractile responses to 5-HT, partly mediated by enhanced responses of 5-HT2A receptors, which was unrelated to changes in the expression of these receptors.
- MeSH
- aorta MeSH
- bronchiální astma * MeSH
- morčata MeSH
- receptory serotoninové 5-HT2 MeSH
- receptory serotoninové metabolismus MeSH
- serotonin * MeSH
- zvířata MeSH
- Check Tag
- morčata MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Serotonin (5-HT) is a biogenic monoamine with diverse functions in multiple human organs and tissues. During pregnancy, tightly regulated levels of 5-HT in the fetoplacental unit are critical for proper placental functions, fetal development, and programming. Despite being a non-neuronal organ, the placenta expresses a suite of homeostatic proteins, membrane transporters and metabolizing enzymes, to regulate monoamine levels. We hypothesized that placental 5-HT clearance is important for maintaining 5-HT levels in the fetoplacental unit. We therefore investigated placental 5-HT uptake from the umbilical circulation at physiological and supraphysiological levels as well as placental metabolism of 5-HT to 5-hydroxyindoleacetic acid (5-HIAA) and 5-HIAA efflux from trophoblast cells. METHODS: We employed a systematic approach using advanced organ-, tissue-, and cellular-level models of the human placenta to investigate the transport and metabolism of 5-HT in the fetoplacental unit. Human placentas from uncomplicated term pregnancies were used for perfusion studies, culturing explants, and isolating primary trophoblast cells. RESULTS: Using the dually perfused placenta, we observed a high and concentration-dependent placental extraction of 5-HT from the fetal circulation. Subsequently, within the placenta, 5-HT was metabolized to 5-hydroxyindoleacetic acid (5-HIAA), which was then unidirectionally excreted to the maternal circulation. In the explant cultures and primary trophoblast cells, we show concentration- and inhibitor-dependent 5-HT uptake and metabolism and subsequent 5-HIAA release into the media. Droplet digital PCR revealed that the dominant gene in all models was MAO-A, supporting the crucial role of 5-HT metabolism in placental 5-HT clearance. CONCLUSIONS: Taken together, we present transcriptional and functional evidence that the human placenta has an efficient 5-HT clearance system involving (1) removal of 5-HT from the fetal circulation by OCT3, (2) metabolism to 5-HIAA by MAO-A, and (3) selective 5-HIAA excretion to the maternal circulation via the MRP2 transporter. This synchronized mechanism is critical for regulating 5-HT in the fetoplacental unit; however, it can be compromised by external insults such as antidepressant drugs.
- MeSH
- aminy MeSH
- kinetika MeSH
- kyselina hydroxyindoloctová MeSH
- lidé MeSH
- placenta * MeSH
- serotonin * MeSH
- těhotenství MeSH
- Check Tag
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The 5-hydroxytryptamine (serotonin) receptor type 7 (5-HT7R) is a G protein-coupled receptor present primarily in the nervous system and gastrointestinal tract, where it regulates mood, cognition, digestion, and vasoconstriction. 5-HT7R has previously been shown to bind to its cognate stimulatory Gs protein in the inactive state. This phenomenon, termed "inverse coupling," is thought to counteract the atypically high intrinsic activity of 5-HT7R. However, it is not clear how active and inactive 5-HT7 receptors affect the mobility of the Gs protein in the plasma membrane. Here, we used single-molecule imaging of the Gs protein and 5-HT7R to evaluate Gs mobility in the membrane in the presence of 5-HT7R and its mutants. We show that expression of 5-HT7R dramatically reduces the diffusion rate of Gs. Expression of the constitutively active mutant 5-HT7R (L173A) is less effective at slowing Gs diffusion presumably due to the reduced ability to form long-lasting inactive complexes. An inactive 5-HT7R (N380K) mutant slows down Gs to the same extent as the wild-type receptor. We conclude that inactive 5-HT7R profoundly affects Gs mobility, which could lead to Gs redistribution in the plasma membrane and alter its availability to other G protein-coupled receptors and effectors.
The type B trichothecenes pollute food crops and have been associated to alimentary toxicosis resulted in emetic reaction in human and animal. This group of mycotoxins consists deoxynivalenol (DON) and four structurally related congeners: 3-acetyl-deoxynivalenol (3-ADON), 15-acetyl deoxynivalenol (15-ADON), nivalenol (NIV) and 4-acetyl-nivalenol (fusarenon X, FX). While emesis induced by intraperitoneally dosed to DON in the mink has been related to plasma up-grading of 5-hydroxytryptamine (5-HT) and neurotransmitters peptide YY (PYY), the impact of oral dosing with DON or its four congeners on secretion of these chemical substances have not been established. The aim of this work was to contraste emetic influence to type B trichothecene mycotoxins by orally dosing and involve these influence to PYY and 5-HT. All five toxins attracted marked emetic reaction that are relevant to elevated PYY and 5-HT. The reduction in vomiting induced by the five toxins and PYY was due to blocking of the neuropeptide Y2 receptor. The inhibition of the induced vomiting response by 5-HT and all five toxins is regulated by the 5-HT3 receptor inhibitor granisetron. In a word, our results indicate that PYY and 5-HT take a key role in the emetic reaction evoked by type B trichothecenes.
- MeSH
- emetika škodlivé účinky MeSH
- lidé MeSH
- mykotoxiny * škodlivé účinky MeSH
- norek MeSH
- peptid YY MeSH
- serotonin MeSH
- trichotheceny typu B * škodlivé účinky MeSH
- trichotheceny * toxicita MeSH
- zvířata MeSH
- zvracení chemicky indukované MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Sensory processing is influenced by neuromodulators such as serotonin, thought to relay behavioural state. Recent work has shown that the modulatory effect of serotonin itself differs with the animal's behavioural state. In primates, including humans, the serotonin system is anatomically important in the primary visual cortex (V1). We previously reported that in awake fixating macaques, serotonin reduces the spiking activity by decreasing response gain in V1. But the effect of serotonin on the local network is unknown. Here, we simultaneously recorded single-unit activity and local field potentials (LFPs) while iontophoretically applying serotonin in V1 of alert monkeys fixating on a video screen for juice rewards. The reduction in spiking response we observed previously is the opposite of the known increase of spiking activity with spatial attention. Conversely, in the local network (LFP), the application of serotonin resulted in changes mirroring the local network effects of previous reports in macaques directing spatial attention to the receptive field. It reduced the LFP power and the spike-field coherence, and the LFP became less predictive of spiking activity, consistent with reduced functional connectivity. We speculate that together, these effects may reflect the sensory side of a serotonergic contribution to quiet vigilance: The lower gain reduces the salience of stimuli to suppress an orienting reflex to novel stimuli, whereas at the network level, visual processing is in a state comparable to that of spatial attention.
- MeSH
- akční potenciály fyziologie MeSH
- lidé MeSH
- Macaca mulatta MeSH
- serotonin MeSH
- světelná stimulace MeSH
- zraková percepce fyziologie MeSH
- zrakové evokované potenciály * MeSH
- zrakové korové centrum * fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Intramural MeSH
Here we present a complex hypothesis about the psychosomatic mechanism of serotonergic psychedelics. Serotonergic psychedelics affect gut microbes that produce a temporary increase of 5-HT by their host enterochromaffin cells (ECs). This increased 5-HT production-which is taken up and distributed by platelets-may work as a hormone-like regulatory signal that could influence membrane permeability in the host organs and tissues and in the brain. Increased plasma 5-HT levels could enhance permeability of the blood-brain barrier (BBB). Transiently increased permeability of the BBB allows for plasma 5-HT to enter the central nervous system (CNS) and be distributed by the volume transmission. Next, this gut-derived 5-HT could modulate excitatory and inhibitory neurotransmission and produce special network disintegration in the CNS. This transient perturbation of the normal neural hierarchy allows patients access to suppressed fear information and perform an emotional reset, in which the amygdale may have a key role.
- MeSH
- halucinogeny * MeSH
- hematoencefalická bariéra MeSH
- hormony MeSH
- lidé MeSH
- mozek MeSH
- serotonin * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
