Effect of deprivation of serotonin by p-chlorophenylalanine on induction and maintenance of pseudopregnancy in female rats

The Immune System and the Role of Inflammation in Perinatal Depression

Major depression during pregnancy is a common psychiatric disorder that arises from a complex and multifactorial etiology. Psychosocial stress, sex, hormones, and genetic vulnerability increase the risk for triggering mood disorders. Microglia and toll-like receptor 4 play a crucial role in triggering wide and varied stress-induced responses mediated through activation of the inflammasome; this leads to the secretion of inflammatory cytokines, increased serotonin metabolism, and reduction of neurotransmitter availability along with hypothalamic-pituitary-adrenal axis hyperactivity. Dysregulation of this intricate neuroimmune communication network during pregnancy modifies the maternal milieu, enhancing the emergence of depressive symptoms and negative obstetric and neuropsychiatric outcomes. Although several studies have clearly demonstrated the role of the innate immune system in major depression, it is still unclear how the placenta, the brain, and the monoaminergic and neuroendocrine systems interact during perinatal depression. Thus, in the present review we describe the cellular and molecular interactions between these systems in major depression during pregnancy, proposing that the same stress-related mechanisms involved in the activation of the NLRP3 inflammasome in microglia and peripheral myeloid cells in depressed patients operate in a similar fashion in the neuroimmune placenta during perinatal depression. Thus, activation of Toll-like receptor 2 and 4 signaling and the NLRP3 inflammasome in placental immune cells may promote a shift of the Th1/Th2 bias towards a predominant Th1/Th17 inflammatory response, associated with increased secretion of pro-inflammatory cytokines, among other secreted autocrine and paracrine mediators, which play a crucial role in triggering and/or exacerbating depressive symptoms during pregnancy.

An international network (PlaNet) to evaluate a human placental testing platform for chemicals safety testing in pregnancy

The human placenta is a critical life-support system that nourishes and protects a rapidly growing fetus; a unique organ, species specific in structure and function. We consider the pressing challenge of providing additional advice on the safety of prescription medicines and environmental exposures in pregnancy and how ex vivo and in vitro human placental models might be advanced to reproducible human placental test systems (HPTSs), refining a weight of evidence to the guidance given around compound risk assessment during pregnancy. The placental pharmacokinetics of xenobiotic transfer, dysregulated placental function in pregnancy-related pathologies and influx/efflux transporter polymorphisms are a few caveats that could be addressed by HPTSs, not the specific focus of current mammalian reproductive toxicology systems. An international consortium, "PlaNet", will bridge academia, industry and regulators to consider screen ability and standardisation issues surrounding these models, with proven reproducibility for introduction into industrial and clinical practice.

Effects of prenatal maternal stress on serotonin and fetal development

Fetuses are exposed to many environmental perturbations that can influence their development. These factors can be easily identifiable such as drugs, chronic diseases or prenatal maternal stress. Recently, it has been demonstrated that the serotonin synthetized by the placenta was crucial for fetal brain development. Moreover, many studies show the involvement of serotonin system alteration in psychiatric disease during childhood and adulthood. This review summarizes existing studies showing that prenatal maternal stress, which induces alteration of serotonin systems (placenta and fetal brain) during a critical window of early development, could lead to alteration of fetal development and increase risks of psychiatric diseases later in life. This phenomenon, termed fetal programming, could be moderated by the sex of the fetus. This review highlights the need to better understand the modification of the maternal, placental and fetal serotonin systems induced by prenatal maternal stress in order to find early biomarkers of psychiatric disorders.

Genetic polymorphisms of serotonin transporter and receptor 1A could influence success during embryo implantation and maintenance of pregnancy

OBJECTIVE

To explore whether serotonin-related gene polymorphisms influence clinical outcomes of IVF treatment in recipients using donated oocytes.

DESIGN

Nested case-control study.

SETTING

University-affiliated infertility clinic.

PATIENT(S)

Two hundred forty-five women undergoing IVF treatment with donated oocytes.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Genotype and haplotype analysis of the serotonin transporter-linked polymorphic region (5-HTTLPR), rs1800532, rs6295, rs6313, and rs3813929, between recipients grouped according to the results of the oocyte donation for IVF treatment.

RESULT(S)

No differences were found between genotype distribution of the tryptophan hydroxylase 1, serotonin receptor 2A, and serotonin receptor 2C polymorphisms. Recipients carrying the LL genotype for 5-HTTLPR had lower clinical pregnancy rates (PR) and higher biochemical pregnancy loss (BPL) events. Lower implantation rates were found in CC carriers for 5-HT1A.rs6295 who also presented higher BPL rates. A lower incidence of clinical pregnancy was observed for LC haplotypes, corresponding to an increase in BPL rates.

CONCLUSION(S)

A strong association was found between early pregnancy loss and recipients carrying the 5-HTTLPR and rs6295 genetic variants. Identifying biological processes involving serotonin and embryo implantation may help to understand the dynamics of the maternal-embryo dialogue.

Monoamine transporters in human endometrium and decidua

BACKGROUND

Monoamines play important roles in decidualization, implantation, immune modulation and inflammation. Furthermore, monoamines are potent vasoactive mediators that regulate blood flow and capillary permeability. Regulation of the uterine blood flow is important both during menstruation and pregnancy. Adequate monoamine concentrations are essential for a proper implantation and physiological development of pregnancy. Unlike most transmitter substances, monoamines are recycled by monoamine transporters rather than enzymatically inactivated. Their intracellular fate is influenced by their lower affinity for inactivating enzymes than for vesicular transporters located in intracellular vesicles. Thus, cells are capable not only of recapturizing and degrading monoamines, but also of storing and releasing them in a controlled fashion.

METHODS

The general objective of the present review is to summarize the role of the monoamine transporters in the female human reproduction. Since the transporter proteins critically regulate extracellular monoamine concentrations, knowledge of their distribution and cyclic variation is of great importance for a deeper understanding of the contribution of monoaminergic mechanisms in the reproductive process. MEDLINE was searched for relevant publications from 1950 to 2007.

RESULTS

Two families of monoamine transporters, neuronal and extraneuronal monoamine transporters, are present in the human endometrium and deciduas.

CONCLUSIONS

New knowledge about monoamine metabolism in the endometrium during menstruation and pregnancy will increase understanding of infertility problems and may offer new pharmacological approaches to optimize assisted reproduction.

The organic cation transporters (OCT1, OCT2, EMT) and the plasma membrane monoamine transporter (PMAT) show differential distribution and cyclic expression pattern in human endometrium and early pregnancy decidua

The non-neuronal monoamine transporters (OCT1, OCT2, EMT, and PMAT) play a key role in the clearance of monoamines from extracellular compartments. In a previous report we described endometrial distribution and cyclic variation of the vesicular monoamine transporter (VMAT2) mRNA and the neuronal norepinephrine transporter (NET) mRNA. In the present study we used in situ hybridization, real-time PCR and immunohistochemistry to reveal tissue distribution and cyclic variation of mRNA for the non-neuronal monoamine transporters in the human endometrium and early pregnancy decidua. We found that non-neuronal monoamine transporters are predominantly expressed in the stroma. The plasma membrane monoamine transporter (PMAT) mRNA expression peaked in the proliferative phase, whereas the extra-neuronal monoamine transporter (EMT) mRNA expression peaked in the secretory phase. The organic cation transporter 2 (OCT2) mRNA expression was exclusively detected in few scattered stromal cells and OCT1 mRNA was not detected at all. Our present results demonstrate that PMAT, EMT, and OCT2 transporters are expressed in the endometrial stroma and can potentially regulate reuptake of monoamines in general and histamine in particular. Taken together with our previous finding of VMAT2 mRNA in epithelial cells, we suggest a paracrine interaction between stromal and epithelial cells, which may modulate certain steps of the reproductive process.

Inhibitory effect of neural transections of dorsal raphe nucleus on induction of nocturnal prolactin surge by vaginal stimulation in ovariectomized rats

The effect of complete (CC), anterior (AC) or posterior (PC) cut of the dorsal raphe nucleus (DRn) on induction of the nocturnal prolactin (PRL) surge by electrical vaginal stimulation (VS) was investigated in ovariectomized rats. Plasma level of PRL was measured by radioimmunoassay before and after VS. The data revealed that PRL levels increased in early morning on the day following VS in the rats without brain surgery or with sham-operation. In contrast, the nocturnal PRL surge did not occur in the CC, AC, or PC rats. These results suggest that both the anterior and the posterior fibers of the DRn plays an important role in induction of nocturnal PRL surge by VS in ovariectomized rats.