Serotonin-estrogen interactions: What can we learn from pregnancy?

Serotonergic Regulation of Synaptic Dopamine Levels Mitigates L-DOPA-Induced Dyskinesia in a Mouse Model of Parkinson's Disease

Background

The serotonin (5-HT) system can manipulate the processing of exogenous L-DOPA in the DA-denervated striatum, resulting in the modulation of L-DOPA-induced dyskinesia (LID).

Objective

To characterize the effects of the serotonin precursor 5-hydroxy-tryptophan (5-HTP) or the serotonin transporter (SERT) inhibitor, Citalopram on L-DOPA-induced behavior, neurochemical signals, and underlying protein expressions in an animal model of Parkinson's disease.

Methods

MitoPark (MP) mice at 20 weeks of age, subjected to a 14-day administration of L-DOPA/Carbidopa, displayed dyskinesia, referred to as LID. Subsequent investigations explored the effects of 5-HT-modifying agents, such as 5-HTP and Citalopram, on abnormal involuntary movements (AIMs), locomotor activity, neurochemical signals, serotonin transporter activity, and protein expression in the DA-denervated striatum of LID MP mice.

Results

5-HTP exhibited duration-dependent suppressive effects on developing and established LID, especially related to abnormal limb movements observed in L-DOPA-primed MP mice. However, Citalopram, predominantly suppressed abnormal axial movement induced by L-DOPA in LID MP mice. We demonstrated that 5-HTP could decrease L-DOPA-upregulation of DA turnover rates while concurrently upregulating 5-HT metabolism. Additionally, 5-HTP was shown to reduce the expressions of p-ERK and p-DARPP-32 in the striatum of LID MP mice. The effect of Citalopram in alleviating LID development may be attributed to downregulation of SERT activity in the dorsal striatum of LID MP mice.

Conclusions

While both single injection of 5-HTP and Citalopram effectively mitigated the development of LID, the difference in mitigation of AIM subtypes may be linked to the unique effects of these two serotonergic agents on L-DOPA-derived DA and 5-HT metabolism.

Emerging Perspectives on the Impact of Diabetes Mellitus and Anti-Diabetic Drugs on Premenstrual Syndrome. A Narrative Review

Diabetes mellitus (DM) and premenstrual syndrome (PMS) are global health challenges. Both disorders are often linked to a range of physical and psychological symptoms that significantly impact the quality of life of many women. Yet, the exact relation between DM and PMS is not clear, and the management of both conditions poses a considerable challenge. In this review, we aimed to investigate the interplay between DM, anti-diabetic drugs, and the different theories and symptoms of PMS. Female sex hormones are implicated in the pathophysiology of PMS and can also impair blood glucose control. In addition, patients with diabetes face a higher susceptibility to anxiety and depression disorders, with a significant number of patients experiencing symptoms such as fatigue and difficulty concentrating, which are reported in patients with PMS as well. Complications related to diabetic medications, such as hypoglycemia (with sulfonylurea) and fluid retention (with thiazolidinediones) may also mediate PMS-like symptoms. DM can, in addition, disturb the normal gut microbiota (GM), with a consequent loss of beneficial GM metabolites that guard against PMS, particularly the short-chain fatty acids and serotonin. Among the several available anti-diabetic drugs, those (1) with an anti-inflammatory potential, (2) that can preserve the beneficial GM, and (3) possessing a lower risk for hypoglycemia, might have a favorable outcome in PMS women. Yet, well-designed clinical trials are needed to investigate the anti-diabetic drug(s) of choice for patients with diabetes and PMS.

The impact of estradiol on serotonin, glutamate, and dopamine systems

Estradiol, the most potent and prevalent member of the estrogen class of steroid hormones and is expressed in both sexes. Functioning as a neuroactive steroid, it plays a crucial role in modulating neurotransmitter systems affecting neuronal circuits and brain functions including learning and memory, reward and sexual behaviors. These neurotransmitter systems encompass the serotonergic, dopaminergic, and glutamatergic signaling pathways. Consequently, this review examines the pivotal role of estradiol and its receptors in the regulation of these neurotransmitter systems in the brain. Through a comprehensive analysis of current literature, we investigate the multifaceted effects of estradiol on key neurotransmitter signaling systems, namely serotonin, dopamine, and glutamate. Findings from rodent models illuminate the impact of hormone manipulations, such as gonadectomy, on the regulation of neuronal brain circuits, providing valuable insights into the connection between hormonal fluctuations and neurotransmitter regulation. Estradiol exerts its effects by binding to three estrogen receptors: estrogen receptor alpha (ERα), estrogen receptor beta (ERβ), and G protein-coupled receptor (GPER). Thus, this review explores the promising outcomes observed with estradiol and estrogen receptor agonists administration in both gonadectomized and/or genetically knockout rodents, suggesting potential therapeutic avenues. Despite limited human studies on this topic, the findings underscore the significance of translational research in bridging the gap between preclinical findings and clinical applications. This approach offers valuable insights into the complex relationship between estradiol and neurotransmitter systems. The integration of evidence from neurotransmitter systems and receptor-specific effects not only enhances our understanding of the neurobiological basis of physiological brain functioning but also provides a comprehensive framework for the understanding of possible pathophysiological mechanisms resulting to disease states. By unraveling the complexities of estradiol's impact on neurotransmitter regulation, this review contributes to advancing the field and lays the groundwork for future research aimed at refining understanding of the relationship between estradiol and neuronal circuits as well as their involvement in brain disorders.

Menstrual Cycle and Situational Match Variables: Effects on Well-Being in Professional Female Soccer Players

Purpose: We examined whether the situational match factors (location, result, and opposition quality), as well as playing position and menstrual cycle phase, influenced self-reported well-being in female soccer players. Methods: Twenty-two professional players (25 ± 5 years) from a squad in the Women's Super League in England self-reported their menstrual cycle phase via an online survey, and their soreness, sleep, stress, mood, and fatigue on a 1 (positive) to 5 (negative) scale on the morning of match day (MD) and for the next 3 days (referred to as MD + 1, MD + 2, MD + 3, respectively). Data was collected for 26 matches across the 2021-2022 season. Session rate of perceived exertion (sRPE) and total distance covered (measured with GPS) were measured on match and training days. Results: Menstrual cycle phase and the situational match factors had no influence on distance covered during matches and sRPE (p > .05). Sleep was worse on MD + 1 (p < .001; g = 1.59) and MD + 2 (p = .005; g = 0.98) after away matches. Stress and mood were > 28% worse after playing top vs. mid and bottom table opposition at MD + 1, and significantly worse when losing compared to winning and drawing (p > .05). Playing position and menstrual cycle phase has no influence on self-reported well-being (p > .05). Conclusion: Sleep quality was worse after away matches and losing matches negatively affects stress and mood for 2 days post-match, but menstrual cycle phase does not influence post-match well-being.

Molecular pathways in placental-fetal development and disruption

The first trimester of pregnancy ranks high in priority when minimizing harmful exposures, given the wide-ranging types of organogenesis occurring between 4- and 12-weeks' gestation. One way to quantify potential harm to the fetus in the first trimester is to measure a corollary effect on the placenta. Placental biomarkers are widely present in maternal circulation, cord blood, and placental tissue biopsied at birth or at the time of pregnancy termination. Here we evaluate ten diverse pathways involving molecules expressed in the first trimester human placenta based on their relevance to normal fetal development and to the hypothesis of placental-fetal endocrine disruption (perturbation in development that results in abnormal endocrine function in the offspring), namely: human chorionic gonadotropin (hCG), thyroid hormone regulation, peroxisome proliferator activated receptor protein gamma (PPARγ), leptin, transforming growth factor beta, epiregulin, growth differentiation factor 15, small nucleolar RNAs, serotonin, and vitamin D. Some of these are well-established as biomarkers of placental-fetal endocrine disruption, while others are not well studied and were selected based on discovery analyses of the placental transcriptome. A literature search on these biomarkers summarizes evidence of placenta-specific production and regulation of each biomarker, and their role in fetal reproductive tract, brain, and other specific domains of fetal development. In this review, we extend the theory of fetal programming to placental-fetal programming.

Hyperemesis gravidarum and eating disorders before and after pregnancy: A register-based study

OBJECTIVE

Hyperemesis gravidarum (HG) is a severe form of excessive vomiting during pregnancy. The connection between psychiatric morbidity and HG has been debated, but only a few studies have focused on eating disorders (EDs). The objective of this study was to evaluate the association between HG and both pre-pregnancy and new post-pregnancy EDs.

METHODS

A register-based controlled study. HG diagnoses were retrieved from healthcare registers between 2005 and 2017. Women with HG in their first pregnancy resulting in delivery were chosen as cases (n = 4265; the HG group) and women with no HG as controls (n = 302,663; the non-HG group). The associations between EDs and HG were analyzed by binary logistic regression, adjusted with age, body mass index, smoking, socioeconomic status, and pre-pregnancy psychiatric diagnoses.

RESULTS

In the HG group, 1.6% and in the non-HG group, 0.2% had a pre-pregnancy ED. Women with ED were more likely to have HG in their first pregnancy compared with women with no history of EDs (adjusted odds ratio [AOR] 9.4, 95% CI 6.52-13.66, p < .0001). Moreover, 0.4% of the women in the HG group and 0.1% of the women in the non-HG group had a new ED diagnosis after pregnancy, and thus the women in the HG group were more likely to have an ED diagnosis after pregnancy (AOR I 3.5, 95% CI 1.71-7.15, p < .001, AOR II 2.7, 95% CI 1.30-5.69, p = .008).

DISCUSSION

We found a bidirectional association between ED and HG, suggesting a shared etiology or risk factors between these disorders. This finding emphasizes the importance of collaboration across various specialties when treating these patients.

PUBLIC SIGNIFICANCE

Our findings suggest a bidirectional association between HG and EDs before and after pregnancy. This finding provides essential information for healthcare professionals working with pregnant women. As both of these disorders are known to have far-reaching effects on the lives of both the mother and her offspring, our results help clinicians to target special attention and interventions to the patients suffering from these disorders.

The antidepressant fluoxetine (Prozac®) modulates serotonin signaling to alter maternal peripartum calcium homeostasis

Antidepressant use is two-fold greater in women compared to men; however, most studies have been performed in male subjects. We aimed to understand the impact of selective serotonin reuptake inhibitors (SSRI, most used antidepressants) on calcium homeostasis and steroid metabolism during the peripartum period. Pregnant sheep (n = 10/group) were treated with vehicle or fluoxetine (most common SSRI) during the last month of gestation. Fluoxetine treatment decreased circulating calcium prior to parturition (8.7 ± 0.1 mg/dL vs 8.2 ± 0.1 mg/dL; P = 0.07). In the control group, total calcium decreased after parturition corresponding to the onset of lactogenesis followed by increase in calcium by day 2 postpartum. Interestingly, this normal transient decrease in circulating calcium was absent in fluoxetine-treated ewes. The steroids cortisol and progesterone were not altered by fluoxetine treatment whereas estradiol was decreased after the onset of treatment (12.4 ± 1.3 vs 9.1 ± 1.2 pg/mL, P = 0.05) and prior to parturition (38.1 ± 8.1 vs 22.3 ± 4.2 pg/mL, P = 0.03). Our hypothesis was supported that fluoxetine treatment alters circulating concentrations of calcium in the peripartum period; however, we surprisingly observed a decrease in estradiol concentrations contrary to reports in in vitro studies.

Efficacy and safety of ondansetron for morning sickness in pregnancy: a systematic review of clinical trials

Background: Ondansetron is a selective antagonist of the serotonin 5-HT3 receptor that is commonly used to treat morning sickness. It is estimated that 70%-80% of pregnant women suffer from morning sickness, a condition characterized by nausea and vomiting. However, it is still controversial regarding its safety during pregnancy, and continued research will be necessary to fully understand the risks and benefits associated with its use. Therefore, we aimed to identify and provide details of the efficacy and safety of ondansetron in clinical trials. Methods: A search was conducted of the ClinicalTrials.gov database on 13 April 2023, using the search term "ondansetron and pregnancy." Inclusion and exclusion criteria were defined to identify relevant clinical trials. The inclusion criteria encompassed clinical trials related to pregnancy that utilized ondansetron as a treatment, while other clinical trials were excluded from consideration. All data extractions such as study title, study status, study type, intervention details, and outcome were collected. Results: A total of 18 clinical trials were identified, of which only 6 focused on studying the effects of ondansetron. Their respective study titles, statuses, conditions, interventions, outcome measures, and enrollment sizes have been written in detail. The information collected from these trials will contribute to our understanding of the potential benefits and risks of ondansetron in the context of pregnancy and its complications. Conclusion: Ondansetron has been shown to be an effective treatment for nausea and vomiting, including pregnancy-related morning sickness. Further research is needed to better understand the potential risks and benefits associated with its use in pregnant women. Systematic Review Registration: ClinicalTrials.gov, identifier.

Metagenomic analysis reveals a dynamic microbiome with diversified adaptive functions that respond to ovulation regulation in the mouse endometrium

Understanding the microflora inhabiting the reproductive tract is important for a better understanding of female physiology and reproductive health. The endometrial fluid from mice in three reproductive stages (A: Unproductive mice; B: Postovulatory mice; C: Postpartum mice) was extracted for microbial DNA extraction and sequencing. Phenotypic and functional analyses of endometrial microbial enrichment was undertaken using LefSe. The results showed 95 genera and 134 species of microorganisms in the uteri of mice. There were differentially distributed genera, among which Lactobacillus, Enterococcus, and Streptococcus were more abundant in the endometrial fluid of mice in the unproductive group. That of mice in the postovulatory group was colonized with Salmonella enterica and Campylobacter and was mainly enriched in metabolic pathways and steroid biosynthesis. The presence of Chlamydia, Enterococcus, Pseudomonadales, Acinetobacter, and Clostridium in the endometrial fluid of postpartum mice, in addition to the enrichment of the endocrine system and the Apelin and FoxO signaling pathways, resulted in a higher number of pathogenic pathways than in the other two groups. The results showed that the microbial diversity characteristics in the endometrium of mice in different reproductive states differed and that they could be involved in the regulation of animal reproduction through metabolic pathways and steroid biosynthesis, suggesting that reproductive diseases induced by microbial diversity alterations in the regulation of animal reproduction cannot be ignored.

Longitudinal Course of Sex Steroids From Pregnancy to Postpartum

CONTEXT

Sex steroids (SS) typically rise during pregnancy and decline after birth, but no consistent reference values exist for these hormonal courses. We aimed to establish an overview of SS secretion patterns during the peripartum and to better understand how SS contribute to maternal and fetal pathologies.

EVIDENCE ACQUISITION

A systematic literature search was conducted in accordance with the PRISMA guidelines using PubMed, Cochrane Library, and PsycINFO. Additionally, we conducted a supplementary manual search of references. Observational studies published in English and assessing estradiol, progesterone, and testosterone over the course of the peripartum in physically healthy female subjects were included, without restrictions on year of publication. Extracted data were analyzed descriptively and visually.

EVIDENCE SYNTHESIS

SS increase progressively during pregnancy, with an extremely wide range of reported concentrations, especially in the third trimester. In fact, reported concentrations varied up to 5000-fold at comparable measurement time points.

CONCLUSIONS

A comprehensive understanding of the influence of SS levels on associated maternal and fetal pathologies is currently hindered by 2 main factors. First, reported SS levels vary widely during the peripartum period. Second, the current state of knowledge on how SS are associated with pathologies in mothers and babies is largely based on correlational studies, and causality thus remains unclear. Consequently, we recommend the development of a systematic reference framework that follows the suggestions presented in this review. This would enable the establishment of SS reference values for a healthy population, resulting in the possibility to draw conclusions about deviations and related pathologies.

Intertwined associations between oxytocin, immune system and major depressive disorder

Major depressive disorder (MDD) is a prominent psychiatric disorder with a high prevalence rate. The recent COVID-19 pandemic has exacerbated the already high prevalence of MDD. Unfortunately, a significant proportion of patients are unresponsive to conventional treatments, necessitating the exploration of novel therapeutic strategies. Oxytocin, an endogenous neuropeptide, has emerged as a promising candidate with anxiolytic and antidepressant properties. Oxytocin has been shown to alleviate emotional disorders by modulating the hypothalamic-pituitary-adrenal (HPA) axis and the central immune system. The dysfunction of the immune system has been strongly linked to the onset and progression of depression. The central immune system is believed to be a key target of oxytocin in ameliorating emotional disorders. In this review, we examine the evidence regarding the interactions between oxytocin, the immune system, and depressive disorder. Moreover, we summarize and speculate on the potential roles of the intertwined association between oxytocin and the central immune system in treating emotional disorders.

New insights on the impact of gut microbiota on premenstrual disorders. Will probiotics solve this mystery?

Premenstrual disorders (PMDs) refer to premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD), where both are characterized by physical and psychological changes occurring in the luteal phase of menstrual cycle. According to the available theories, there is no single accusation succeeded to explain the pathophysiology of PMDs. However, there is emerging evidence for the role of gut microbiota (GM) in PMDs, supported by the diverging impact of GM on our body systems. The direct secretory function of GM and their integration in hormonal, neurotransmitters and bioactive compounds secretion and activity reinforce this speculation. Moreover, the bidirectional relation between GM and steroid hormones and the impact of diet, drugs, and inflammation on both, GM and PMDs incidence and severity justify the need for more studies to determine the actual role of GM in PMDs and the possible potential of probiotics and prebiotics as therapeutic options.

To clot, or not to clot: The dilemma of hormone treatment options for menopause

Untreated menopause may have serious health implications, but treatments can have dangerous side effects. We evaluate menopausal symptoms as well as available treatments -the routes of administration and their effect on blood coagulation. Menopausal females may experience hot flushes, vulva- and vaginal atrophy and osteoporosis. Many treatments are available to relieve these symptoms such as Conjugated Equine Estrogen and bioidentical hormones. The routes of administration include oral and transdermal. Hormones that are administered orally undergo a hepatic first pass metabolism. The by-products have a lower efficacy and possibly enhanced side effects. Furthermore, hormone treatments influence the coagulation cascade through coagulation factors or their regulators. Increased coagulation poses a risk for venous thromboembolism. Currently a definite conclusion on whether the side effects from hormone treatments exceed the risk of untreated menopause cannot be made. However, a more individualised approach to hormone treatments may be the most feasible solution to this dilemma.

Sex differences in carcinoid syndrome: A gap to be closed

The incidence of neuroendocrine neoplasms and related carcinoid syndrome (CS) has markedly increased over the last decades and women seem to be more at risk than men for developing CS. Nevertheless, very few studies have investigated sex differences in clinical presentation and outcomes of CS. However, as per other tumours, sex might be relevant in influencing tumour localization, delay in diagnosis, clinical outcomes, prognosis and overall survival in CS. The present review was aimed at evaluating sex differences in CS, as they emerge from an extensive search of the recent literature. It emerged that CS occurs more frequently in female than in male patients with NENs and women seem to have a better prognosis and a slight advantage in overall survival and response to therapy. Moreover, the disease likely impacts differently the quality of life of men and women, with different psychological and social consequences. Nevertheless, sex differences, even if partially known, are deeply underestimated in clinical practice and data from clinical trials are lacking. There is urgent need to increase our understanding of the sex-related differences of CS, in order to define tailored strategies of management of the disease, improving both the quality of life and the prognosis of affected patients.

Maternal Prepregnancy 5-Hydroxytryptamine Exposure Affects the Early Development of the Fetus

In recent decades, the increasing incidence of depression has contributed to an increase in the use of serotonergic drugs, such as antidepressants, which predisposes humans to serotonin syndrome. Serotonin syndrome is caused by elevated serotonin levels in the central and peripheral nervous systems. It has been well documented that the development of offspring can be affected by maternal exposure to environmental challenges, such as stress, diseases, or an unhealthy diet during pregnancy. Serotonin, also called 5-hydroxytryptamine (5-HT), is widely expressed in the female reproductive system and plays an important role in the development of follicles and embryos. However, whether the suffering of the mother from serotonin syndrome before pregnancy affects fetal development is still uncertain. In the present study, to explore the effect of maternal prepregnancy 5-HT exposure on the fetus, intraperitoneal injection of 5-HT was used to change maternal prepregnancy 5-HT levels. It was found that maternal prepregnancy 5-HT exposure significantly reduced the body weight and liver weight and the levels of estrogen and progesterone in female mice. Although there was no significant difference in the cleavage rate and blastocyst rate between the 5-HT and control groups, maternal prepregnancy 5-HT exposure increased the percentage of embryo resorption, decreased placental weight, and led to placental inflammation at E13.5. Notably, 5-HT exposure caused weight loss in the offspring at 2 weeks. These results suggested that maternal prepregnancy 5-HT exposure could affect the development of the offspring, which was partly caused by reduced hormonal secretion and placental inflammation.

Genetic Susceptibility Toward Nausea and Vomiting in Surgical Patients

Postoperative nausea and vomiting (PONV) are frequently occurring adverse effects following surgical procedures. Despite predictive risk scores and a pallet of prophylactic antiemetic treatments, it is still estimated to affect around 30% of the patients, reducing their well-being and increasing the burden of post-operative care. The aim of the current study was to characterize selected genetic risk factors of PONV to improve the identification of at risk patients. We genotyped 601 patients followed during the first 24 h after surgery for PONV symptoms in the absence of any antiemetic prophylaxis. These patients were recruited in the frame of a randomized, placebo controlled clinical study aiming to test the efficacy of dexamethasone as a treatment of established PONV. We examined the impact of selected single nucleotide polymorphisms (SNPs) located around 13 different genes and the predicted activity of 6 liver drug metabolizing enzymes from the cytochromes P450 family (CYP) on the occurrence and recurrence of PONV. Our genetic study confirms the importance of genetic variations in the type 3B serotonin receptor in the occurrence of PONV. Our modelling shows that integration of rs3782025 genotype in preoperative risk assessments may help improve the targeting of antiemetic prophylaxis towards patients at risk of PONV.

Antidepressant use during pregnancy and development of preeclampsia: A focus on classes of action and specific transporters/receptors targeted by antidepressants

OBJECTIVE

The association between antidepressants and preeclampsia has been inconsistently reported. Given the compound-specific variable affinity for different transporters/receptors, their effect on preeclampsia risk could differ. Our study examined the risk of preeclampsia (and its subtypes) following exposure to different classes of antidepressants, also accounting for specific transporters/receptors targeted by antidepressants.

METHODS

We conducted a cohort study, combining data from the Netherlands Perinatal Registry and the PHARMO Database Network. Exposure to antidepressants was examined from conception to week 20 of gestation; extended use thereafter was also studied. Antidepressants were categorized according to classes [selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), serotonin-norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs) and other antidepressants] and according to target transporters/receptors. Women not using any antidepressants during 15 months before delivery were included as reference.

RESULTS

We included 2,103 exposed and 95,376 reference women. Preeclampsia occurred in 70 exposed women (15 early-onset, 55 late-onset) and in 2,582 reference women (387 early-onset, 2,195 late-onset). TCA monotherapy (214 women) was associated with an increased risk of preeclampsia (n = 15, RR 2.46, 95% CI 1.51-4.02) and late-onset preeclampsia (n = 12, RR 2.41, 95% CI 1.39-4.17, early-onset could not be evaluated). No association was detected with SSRIs, SNRIs and MAOIs. We did observe an increased risk of early-onset preeclampsia following exposure to 5-HT2A antagonizing antidepressants (6/405 women, excluding TCA users, RR 3.56, 95% CI 1.60-7.94).

CONCLUSIONS

Our results support an increased risk of preeclampsia and the late-onset subtype among TCA users. The association between 5-HT2A antagonists and the early-onset subtype needs to be interpreted with caution based on the relatively small number of exposed cases.

Regulating Gut Microbiome: Therapeutic Strategy for Rheumatoid Arthritis During Pregnancy and Lactation

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial inflammation and bone destruction. Microbial infection is considered to be the most important inducement of RA. The pregnancy planning of women in childbearing age is seriously affected by the disease activity of RA. Gut microbiome, related to immunity and inflammatory response of the host. At present, emerging evidence suggested there are significant differences in the diversity and abundance of gut microbiome during pregnancy and lactation, which may be associated with the fluctuation of RA disease activity. Based on these research foundations, we pioneer the idea of regulating gut microbiome for the treatment of RA during pregnancy and lactation. In this review, we mainly introduce the potential treatment strategies for controlling the disease activity of RA based on gut microbiome during pregnancy and lactation. Besides, we also briefly generalize the effects of conventional anti-rheumatic drugs on gut microbiome, the effects of metabolic changes during pregnancy on gut microbiome, alteration of gut microbiome during pregnancy and lactation, and the effects of anti-rheumatic drugs commonly used during pregnancy and lactation on gut microbiome. These will provide a clear knowledge framework for researchers in immune-related diseases during pregnancy. Regulating gut microbiome may be a potential and effective treatment to control the disease activity of RA during pregnancy and lactation.

Role of neurotrophins in pregnancy and offspring brain development

Neurotrophins are a family of functionally and structurally related proteins which play a key role in the survival, development, and function of neurons in both the central and peripheral nervous systems. Brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4) are the family members of neurotrophins. Neurotrophins play a crucial role in influencing the development of the brain and learning and memory processes. Studies demonstrate that they also play crucial role in influencing reproductive and immune systems. Neurotrophins have been shown to influence various processes in the mother, placenta, and fetus during pregnancy. Development and maturation of feto-placental unit and the fetal growth trajectories are influenced by neurotrophins. In addition to neurotrophins, neuropeptides like neuropeptide Y also play a crucial role during various processes of pregnancy and during fetal brain development. Neurotrophins have also been shown to have a cross talk with various angiogenic factors and influence placental development. Alterations in the levels of neurotrophins and neuropeptides lead to placental pathologies resulting in various pregnancy complications like preeclampsia, intrauterine growth restriction and preterm births. Studies in animals have reported low levels of maternal micronutrients like folic acid, vitamin B₁₂ and omega-3 fatty acids influence brain neurotrophins resulting in impaired cognitive functioning in the offspring. Maternal nutrition is also known to affect the expression of neuropeptides. It is essential to understand the role of various neurotrophins across various stages of pregnancy and its relationship with neurodevelopmental outcomes in children. This will lead to early prediction of poor neurodevelopmental outcomes. The present review describes evidence describing the role of neurotrophins in determining pregnancy outcome and altered neurodevelopment in the offspring. The possible mechanism through which maternal nutrition influences neurotrophins and neuropeptides to regulate offspring brain development and function is also discussed.

Headaches during pregnancy

Headache during pregnancy is frequent and challenging. A secondary headache is diagnosed in one third of women, and most causes are vascular and infectious disorders. Anamnestic and clinical features must be investigated, and brain imaging is often required. Primary headaches are commonly modified during pregnancy. Migraine is mainly improved in this context, especially migraine without aura. Particular cautions about treatment must be applied, and non-pharmacological measures must be preferred. Tension-type headache and cluster headache seem to be less hormone-dependent.

Comparison of Vascular Responses to Vasoconstrictors in Human Placenta in Preeclampsia between Preterm and Later Term

BACKGROUND

Placental blood vessels play important roles in maternal-fetal circulation. Although pathologic mechanisms of preeclampsia are unclear, it is known that placental vascular dysfunction could contribute to pregnant hypertension. However, placental micro-vessel function or dysfunction at preterm has not been investigated.

METHODS

Human placentas from normal and preeclamptic pregnancies at preterm and term were obtained. Placental micro-vessels were used for determining vascular tension and responses to various vasoconstrictors as well as intracellular calcium store capability. It was the first time to show vascular responses in placental arteries to angiotensin II, endothelin-1, and other vascular drugs at preterm.

RESULTS

Compared to the control, placental vascular contractile responses to angiotensin II and caffeine were significantly decreased, while placental vascular responses to KCl, endothelin-1, and bradykinin were not significantly altered in the later term group in preeclampsia. In comparison of placental micro-vessel tension between the preterm and later term, caffeine- and serotonin-induced vascular contractions were significantly weaker in the preterm than that in the later term. On the contrary, vascular response to angiotensin II was increased in the preterm preeclampsia, while KCl-, endothelin-1, and bradykinin-mediated placental vessel responses in the preterm preeclampsia were similar to that in later term preeclampsia.

CONCLUSION

New data showed that micro-vessel responses to angiotensin II and serotonin, not endothelin- 1 or bradykinin, were significantly reduced in the human placentas at preterm, and intracellular Ca2+ store capacity was damaged too, providing important information on possible contributions of placental vascular dysfunction to pregnant hypertension.

Integrating Pathophysiology in Migraine: Role of the Gut Microbiome and Melatonin

BACKGROUND

The pathoetiology and pathophysiology of migraine are widely accepted as unknown.

METHODS

The current article reviews the wide array of data associated with the biological underpinnings of migraine and provides a framework that integrates previously disparate bodies of data.

RESULTS

The importance of alterations in stress- and pro-inflammatory cytokine- induced gut dysbiosis, especially butyrate production, are highlighted. This is linked to a decrease in the availability of melatonin, and a relative increase in the N-acetylserotonin/melatonin ratio, which has consequences for the heightened glutamatergic excitatory transmission in migraine. It is proposed that suboptimal mitochondria functioning and metabolic regulation drive alterations in astrocytes and satellite glial cells that underpin the vasoregulatory and nociceptive changes in migraine.

CONCLUSION

This provides a framework not only for classical migraine associated factors, such as calcitonin-gene related peptide and serotonin, but also for wider factors in the developmental pathoetiology of migraine. A number of future research and treatment implications arise, including the clinical utilization of sodium butyrate and melatonin in the management of migraine.

Androgen-dependent sexual dimorphism in pituitary tryptophan hydroxylase expression: relevance to sex differences in pituitary hormones

Serotonin is a biogenic monoamine conserved across phyla that is implicated in diverse physiological and behavioural functions. On examining the expression of the rate-limiting enzymes in serotonin synthesis, tryptophan hydroxylases (TPHs), in the teleost medaka (Oryzias latipes), we found that males have much higher levels of tph1 expression as compared with females. This robust sexual dimorphism was found to probably result from the direct stimulation of tph1 transcription by androgen/androgen receptor binding to canonical bipartite androgen-responsive elements in its proximal promoter region. Our results further revealed that tph1 expression occurs exclusively in pro-opiomelanocortin (pomc)-expressing cells and that the resulting serotonin and its derivative melatonin inhibit the expression of the pituitary hormone genes, fshb, sl and tshb. This suggests that serotonin and/or melatonin synthesized in pomc-expressing cells act in a paracrine manner to suppress pituitary hormone levels. Consistent with these findings and the male-biased expression of tph1, the expression levels of fshb, sl and tshb were all higher in females than in males. Taken together, the male bias in tph1 expression and consequent serotonin/melatonin production presumably contribute to sex differences in the expression of pituitary hormones and ultimately in the physiological functions mediated by them.

Hypoxic Adaptation of Mitochondrial Metabolism in Rat Cerebellum Decreases in Pregnancy

Function of brain amino acids as neurotransmitters or their precursors implies changes in the amino acid levels and/or metabolism in response to physiological and environmental challenges. Modelling such challenges by pregnancy and/or hypoxia, we characterize the amino acid pool in the rat cerebellum, quantifying the levels and correlations of 15 amino acids and activity of 2-oxoglutarate dehydrogenase complex (OGDHC). The parameters are systemic indicators of metabolism because OGDHC limits the flux through mitochondrial TCA cycle, where amino acids are degraded and their precursors synthesized. Compared to non-pregnant state, pregnancy increases the cerebellar content of glutamate and tryptophan, decreasing interdependence between the quantified components of amino acid metabolism. In response to hypoxia, the dependence of cerebellar amino acid pool on OGDHC and the average levels of arginine, glutamate, lysine, methionine, serine, phenylalanine, and tryptophan increase in non-pregnant rats only. This is accompanied by a higher hypoxic resistance of the non-pregnant vs. pregnant rats, pointing to adaptive significance of the hypoxia-induced changes in the cerebellar amino acid metabolism. These adaptive mechanisms are not effective in the pregnancy-changed metabolic network. Thus, the cerebellar amino acid levels and OGDHC activity provide sensitive markers of the physiology-dependent organization of metabolic network and its stress adaptations.

Serotonin and serotonin reuptake inhibitors alter placental aromatase

Serotonin reuptake inhibitors (SRIs) are currently the main molecules prescribed to pregnant women that suffer from depression. Placental cells are exposed to SRIs via maternal blood, and we have previously shown that SRIs alter feto-placental steroidogenesis in an in vitro co-culture model. More specifically, serotonin (5-HT) regulates the estrogen biosynthetic enzyme aromatase (cytochrome P450 19; CYP19), which is disrupted by fluoxetine and its active metabolite norfluoxetine in BeWo choriocarcinoma cells. Based on molecular simulations, the present study illustrates that the SRIs fluoxetine, norfluoxetine, paroxetine, sertraline, citalopram and venlafaxine exhibit binding affinity for the active-site pocket of CYP19, suggesting potential competitive inhibition. Using BeWo cells and primary villous trophoblast cells isolated from normal term placentas, we compared the effects of the SRIs on CYP19 activity. We observed that paroxetine and sertraline induce aromatase activity in BeWo cells, while venlafaxine, fluoxetine, paroxetine and sertraline decrease aromatase activity in primary villous trophoblast. The effects of paroxetine and sertraline in primary villous trophoblasts were observed at the lower doses tested. We also showed that 5-HT and the 5-HT_2A receptor agonist 2,5-dimethoxy-4-iodoamphetamine (DOI) induced CYP19 activity. An increase in phosphorylation of serine and tyrosine and a decrease in threonine phosphorylation of CYP19 was also associated with DOI treatment. Our results contribute to better understanding how 5-HT and SRIs interact with CYP19 and may affect estrogen production. Moreover, this study suggests that alteration of placental 5-HT levels due to depression and/or SRI treatment during pregnancy may be associated with disruption of placental estrogen production.

Illicit Upregulation of Serotonin Signaling Pathway in Adrenals of Patients With High Plasma or Intra-Adrenal ACTH Levels

CONTEXT

In the human adrenal, serotonin (5-HT), released by mast cells stimulates corticosteroid secretion through activation of type 4 serotonin receptors (5-HT4R). In primary pigmented nodular adrenocortical disease cells, activation of the cAMP/protein kinase A (PKA) pathway by PRKAR1A mutations triggers upregulation of the 5-HT synthesizing enzyme tryptophan hydroxylase (TPH) and the 5-HT4, 5-HT6, and 5-HT7 receptors. Because ACTH stimulates cortisol secretion through activation of PKA, adrenocortical tissues exposed to sustained stimulation by ACTH may harbor increased expression of TPH and 5-HT4/6/7 receptors.

OBJECTIVE

To investigate the effects of long-term ACTH stimulation on the serotonergic pathway in adrenals of patients with high plasma or intra-adrenal ACTH levels.

METHODS

Adrenal tissues were obtained from patients with Cushing disease, ectopic secretion of ACTH [paraneoplastic Cushing syndrome; (paraCS)], 21-hydroxylase deficiency (21-OHD), primary bilateral macronodular adrenal hyperplasia with intra-adrenal ACTH presence, or cortisol-producing adenomas. TPH and 5-HT4/6/7 receptor expression was investigated using RT-PCR and immunochemistry in comparison with normal adrenals. Primary cultured adrenocortical cells originating from a patient with paraCS were incubated with 5-HT and 5-HTR agonists/antagonists.

RESULTS

TPH and/or 5-HT4/6/7 receptors were overexpressed in the different types of tissues. In paraCS cultured cells, the cortisol response to 5-HT was exaggerated compared with normal adrenal cells and the stimulatory action of 5-HT was reduced by 5-HT4R antagonist.

CONCLUSION

Our results indicate that prolonged activation of the cAMP/PKA pathway by ACTH induces an aberrant serotonergic stimulatory loop in the adrenal cortex that likely participates in the pathogenesis of corticosteroid hypersecretion.