The IDO genetic polymorphisms and postpartum depressive symptoms: an association study in Chinese parturients who underwent cesarean section

Potential therapeutic effects of Chinese herbal medicine in postpartum depression: Mechanisms and future directions

ETHNOPHARMACOLOGICAL RELEVANCE

Postpartum depression (PPD) is a common psychiatric disorder in women after childbirth. Per data from epidemiologic studies, PPD affects about 5%-26.32% of postpartum mothers worldwide. Biological factors underlying this condition are multiple and complex and have received extensive inquiries for the roles they play in PPD. Chinese herbal medicine (CHM), which is widely used as a complementary and alternative therapy for neurological disorders, possesses multi-component, multi-target, multi-access, and low side effect therapeutic characteristics. CHM has already shown efficacy in the treatment of PPD, and a lot more research exploring the mechanisms of its potential therapeutic effects is being conducted.

AIM OF THE REVIEW

This review provides an in-depth and comprehensive overview of the underlying mechanisms of PPD, as well as samples the progress made in researching the potential role of CHM in treating the disorder.

MATERIALS AND METHODS

Literature was searched comprehensively in scholarly electronic databases, including PubMed, Web of Science, Scopus, CNKI and WanFang DATA, using the search terms "postpartum depression", "genetic", "hormone", "immune", "neuroinflammation", "inflammation", "neurotransmitter", "neurogenesis", "brain-gut axis", "traditional Chinese medicine", "Chinese herbal medicine", "herb", and an assorted combination of these terms.

RESULTS

PPD is closely associated with genetics, as well as with the hormones, immune inflammatory, and neurotransmitter systems, neurogenesis, and gut microbes, and these biological factors often interact and work together to cause PPD. For example, inflammatory factors could suppress the production of the neurotransmitter serotonin by inducing the regulation of tryptophan-kynurenine in the direction of neurotoxicity. Many CHM constituents improve anxiety- and depression-like behaviors by interfering with the above-mentioned mechanisms and have shown decent efficacy clinically against PPD. For example, Shen-Qi-Jie-Yu-Fang invigorates the neuroendocrine system by boosting the hormone levels of hypothalamic pituitary adrenal (HPA) and hypothalamic pituitary gonadal (HPG) axes, regulating the imbalance of Treg/T-helper cells (Th) 17 and Th1/Th2, and modulating neurotransmitter system to play antidepressant roles. The Shenguiren Mixture interferes with the extracellular signal-regulated kinase (ERK) pathway to enhance the number, morphology and apoptosis of neurons in the hippocampus of PPD rats. Other herbal extracts and active ingredients of CHM, such as Paeoniflorin, hypericin, timosaponin B-III and more, also manage depression by remedying the neuroendocrine system and reducing neuroinflammation.

CONCLUSIONS

The pathogenesis of PPD is complex and diverse, with the main pathogenesis not clear. Still, CHM constituents, like Shen-Qi-Jie-Yu-Fang, the Shenguiren Mixture, Paeoniflorin, hypericin and other Chinese Medicinal Formulae, active monomers and Crude extracts, treats PPD through multifaceted interventions. Therefore, developing more CHM components for the treatment of PPD is an essential step forward.

Genetic Markers Associated with Postpartum Depression: A Review

Postpartum depression (PPD) is a common illness in mothers after childbirth. PPD negatively affect the mother's quality of life and the bond with the infant, which can interfere with the infant's emotional, social, and cognitive development. PPD is caused by various biological and psychosocial factors. The aim of this review is to summarize the latest evidence of the associations between genetic polymorphisms and PPD. PubMed and Scopus were used as the literature search databases for this review. The keywords used were postpartum depression, postnatal depression, genetic, and polymorphism. Twenty-seven articles were reviewed after screening and applying the inclusion criteria. As results, the serotonin gene (5-HTTLPR) and oxytocin genes (OXTR) have the most significant associations with PPD among other genes. Further research on PPD biomarkers should be conducted to diagnose and treat PPD patients.

Lactogenesis factors in the Asian population

The increasing incidence of disrupted lactogenesis in Asian populations underscores the importance of timely identification and efficient intervention. This study acknowledges the influence of ethnicity on genetic variations and aims to investigate the genetic mechanisms that contribute to lactogenesis in individuals of Asian descent. This study examines the possibilities of genetic screening as a means of applying preventive measures, with a particular focus on epigenetic techniques. Additionally, the analysis looks into the underlying mechanisms involved in milk production. This review discusses the intricate mechanisms underlying breast milk production and the potential influence of genetic variables on lactogenesis. Specifically, it explores the association between lactogenesis issues and genetic conditions such as depression, obesity, gestational hypertension, and gestational diabetes. These genetic factors could potentially be found by genetic screening as contributors to disruption in lactogenesis. This study aims to promote future investigation in the subject of genetic testing and its potential association with lactogenesis issues, despite the current scarcity of direct research on this topic. The statement posits that the progress made in genetic testing has the potential to provide novel insights into the timely identification and treatment of disrupted lactogenesis.

Effects of different doses of esketamine intervention on postpartum depressive symptoms in cesarean section women: A randomized, double-blind, controlled clinical study

BACKGROUND

The optimal dosage and method of esketamine for postpartum depressive symptoms (PDS) are unclear. We conducted a randomized controlled trial (RCT) to investigate the effect of different doses of esketamine on PDS in women undergoing cesarean section, with evidence of prenatal depression.

METHODS

The three groups were high- (2 mg kg-1) and low-dose (1 mg kg-1) esketamine via patient controlled intravenous analgesia (PCIA), following an initial intravenous infusion of 0.25 mg kg-1 esketamine, compared to placebo (0.9 % saline infusion). All groups also received the sufentanil (2.2 μg kg-1). The primary outcome was the incidence of PDS at 7 and 42 days postpartum. The secondary outcomes were: the remission from depression and total EPDS scores at 7 days and 42 days postpartum; mean change from baseline in the EPDS score; postoperative analgesia.

RESULTS

i). 0.25 mg kg-1 of esketamine intravenous infusion combined with 1 mg kg-1 (n = 99) or 2 mg kg-1 (n = 99) esketamine PCIA reduces PDS incidence at 7 days postpartum (p < 0.05), with high-dose esketamine PCIA also reduces PDS incidence 42 days postpartum (p < 0.05), compared to placebo (n = 97). ii). Low- and high-dose esketamine PCIA lowers NRS scores at rest within 48 h postoperatively (p < 0.01), with high-dose esketamine also reducing the NRS score during movement at 48 h postoperatively (p = 0.018). iii). Neither high- nor low-dose esketamine PCIA increased postoperative adverse reactions (p > 0.05).

CONCLUSIONS

Esketamine (0.25 mg kg-1) intravenous infusion combined with 1 mg kg-1 or 2 mg kg-1 esketamine PCIA seems safe and with few adverse effects in the management of PDS and pain in women undergoing cesarean section.

LIMITATIONS

The tolerability and safety of esketamine requires further investigation based on more specific scales; the transient side effects of esketamine could have biased the staff and patients.

TRIAL REGISTRATION

ChiCTR-ROC-2000039069.

Risk Factors for Postpartum Depression Based on Genetic and Epigenetic Interactions

Postpartum depression (PPD) is a serious mood disorder that tends to occur after the delivery, which may bring lifelong consequences to women and their families in terms of family relationships, social relationships, and mental health. Currently, various risk factors including environmental factors and genetic factors that may induce postpartum depression have been extensively studied. In this review, we suggest that postpartum women's susceptibility to postpartum depression may be the result of the interaction between the genes associated with postpartum depression as well as the interaction between genetic and environmental factors. We reviewed the genes that have been studied in postpartum depression, including genes related to the synthesis, metabolism, and transport of monoamine neurotransmitters, key molecules of the HPA axis, and the kynurenine pathway. These studies have found more or less gene-gene and gene-environment interactions, so we will discuss these issues in more detail. However, so far, the conclusions of these risk factors, especially genetic factors, are not completely consistent in the occurrence and exacerbation of symptoms in postpartum depression, and it is not clear how these risk factors specifically participate in the pathological mechanism of the disease and play a role. We conclude that the role of genetic polymorphisms, including genetic and epigenetic processes, in the occurrence and development of postpartum depression, is complex and ambiguous. We also note that interactions between multiple candidate genes and the environment have been suggested as causes of depression, suggesting that more definitive research is needed to understand the heritability and susceptibility of PPD. Overall, our work supports the hypothesis that postpartum depression is more likely to be caused by a combination of multiple genetic and environmental factors than by a single genetic or environmental influence.

The association between tryptophan levels and postpartum mood disorders: a systematic review and meta-analysis

Over 50% of women experience mood disturbance in the postpartum period, with significant implications for maternal and infant health but identifying those at risk is not easily possible. The essential amino acid, tryptophan (TRP) through its neuroactive metabolites, has been implicated in the pathology of mood disorders. Thus, TRP levels tested in the peripartum period have been proposed as a potential biomarker for subsequent development of postpartum mood disturbances, in particular postpartum depression (PPD). A systematic review and meta-analysis following PROSPERO guidelines [CRD42021252462] was conducted on peer-reviewed, English language studies that measured blood levels of TRP during the postpartum period in women who were also evaluated for postpartum "blues" or PPD. Thirteen studies met the inclusion criteria, of which five studies contained sufficient data to conduct a meta-analysis. Low total TRP levels in postpartum days 1 to 5 were significantly associated with PPD (SMD: -5.39, 95%CI [-7.72, -3.05]). No significant association was found between free TRP levels in the postpartum period and PPD (SMD: -3.43, 95%CI [-7.76, 0.89]). Our findings confirm the necessity for more replicable designed studies regarding TRP and its relationship to postpartum depression. If there were greater clarity regarding TRP metabolism during pregnancy, then the next step would be to consider measuring total plasma TRP levels on postpartum days 1 to 5 to identify women at greater risk of developing PPD.

Tryptophan intake is related to a lower prevalence of depressive symptoms during pregnancy in Japan: baseline data from the Kyushu Okinawa Maternal and Child Health Study

OBJECTIVE

Tryptophan is an essential amino acid wholly derived from diet. While the majority of tryptophan is degraded through the kynurenine pathway into neuroactive metabolites like quinolinic acid and kynurenic acid, a small proportion of ingested tryptophan is metabolized into the neurotransmitter serotonin. The current cross-sectional study in Japan examined the association between tryptophan intake and depressive symptoms during pregnancy.

METHODS

Study subjects were 1744 pregnant women. Dietary intake during the preceding month was assessed using a self-administered diet history questionnaire. Depressive symptoms were defined as a score ≥ 16 on the Center for Epidemiologic Studies Depression Scale. Adjustment was made for age, gestation, region of residence, number of children, family structure, history of depression, family history of depression, smoking, secondhand smoke exposure at home and at work, employment, household income, education, body mass index, and intake of saturated fatty acids, eicosapentaenoic acid plus docosahexaenoic acid, calcium, vitamin D, and isoflavones.

RESULTS

The prevalence of depressive symptoms during pregnancy was 19.2%. After adjustment for confounding factors, higher tryptophan intake was independently inversely associated with the prevalence of depressive symptoms during pregnancy: the adjusted prevalence ratios (95% confidence intervals) for depressive symptoms during pregnancy in the first, second, third, and fourth quartiles of tryptophan intake were 1 (reference), 0.99 (0.76-1.28), 0.94 (0.71-1.25), and 0.64 (0.44-0.93), respectively (p for trend = 0.04).

CONCLUSIONS

Higher estimated tryptophan intake was cross-sectionally independently associated with a lower prevalence of depressive symptoms during pregnancy in Japanese women.

A single intravenous administration of a sub-anesthetic ketamine dose during the perioperative period of cesarean section for preventing postpartum depression: A meta-analysis

The feasibility of intravenous ketamine administration during the perioperative period of cesarean section to prevent postpartum depression (PPD) has not been determined by meta-analysis. To evaluate the efficacy, safety and dose of prophylactic ketamine in offsetting PPD, we retrieved the following databases in English or Chinese from inception to December 2020: Pubmed, Embase, Web of Science, The Cochrane Library, CNKI, VIP and Wanfang. A total of 10 studies (9 RCTs and 1 retrospective study) were included with 2087 cases. Meta-analysis showed that in ketamine group, the score and the prevalence of PPD within 1 week postpartum were significantly reduced, whereas PPD score after 4 weeks postpartum showed no superiority. There was no significant difference in terms of total adverse events rate, although vomiting occurred more frequently in the ketamine group. In addition, we found that ketamine efficacy emerged at 0.5 mg/kg. By meta-regression, we observed that: (1) Age and BMI are negatively associated with mood response to ketamine. (2) An analgesic pump containing ketamine for continuous 48 h postpartum administration was more efficacious than an intravenous injection of ketamine during cesarean section. Current evidence shows ketamine could be efficacious and safe in the prophylactic management of PPD in women having a cesarean section.

Biological, Psychological, and Social Determinants of Depression: A Review of Recent Literature

Depression is one of the leading causes of disability, and, if left unmanaged, it can increase the risk for suicide. The evidence base on the determinants of depression is fragmented, which makes the interpretation of the results across studies difficult. The objective of this study is to conduct a thorough synthesis of the literature assessing the biological, psychological, and social determinants of depression in order to piece together the puzzle of the key factors that are related to this condition. Titles and abstracts published between 2017 and 2020 were identified in PubMed, as well as Medline, Scopus, and PsycInfo. Key words relating to biological, social, and psychological determinants as well as depression were applied to the databases, and the screening and data charting of the documents took place. We included 470 documents in this literature review. The findings showed that there are a plethora of risk and protective factors (relating to biological, psychological, and social determinants) that are related to depression; these determinants are interlinked and influence depression outcomes through a web of causation. In this paper, we describe and present the vast, fragmented, and complex literature related to this topic. This review may be used to guide practice, public health efforts, policy, and research related to mental health and, specifically, depression.

The effects of genotype on inflammatory response in hippocampal progenitor cells: A computational approach

Cell culture models are valuable tools to study biological mechanisms underlying health and disease in a controlled environment. Although their genotype influences their phenotype, subtle genetic variations in cell lines are rarely characterised and taken into account for in vitro studies. To investigate how the genetic makeup of a cell line might affect the cellular response to inflammation, we characterised the single nucleotide variants (SNPs) relevant to inflammation-related genes in an established hippocampal progenitor cell line (HPC0A07/03C) that is frequently used as an in vitro model for hippocampal neurogenesis (HN). SNPs were identified using a genotyping array, and genes associated with chronic inflammatory and neuroinflammatory response gene ontology terms were retrieved using the AmiGO application. SNPs associated with these genes were then extracted from the genotyping dataset, for which a literature search was conducted, yielding relevant research articles for a total of 17 SNPs. Of these variants, 10 were found to potentially affect hippocampal neurogenesis whereby a majority (n=7) is likely to reduce neurogenesis under inflammatory conditions. Taken together, the existing literature seems to suggest that all stages of hippocampal neurogenesis could be negatively affected due to the genetic makeup in HPC0A07/03C cells under inflammation. Additional experiments will be needed to validate these specific findings in a laboratory setting. However, this computational approach already confirms that in vitro studies in general should control for cell lines subtle genetic variations which could mask or exacerbate findings.

Neuroinflammation and the Kynurenine Pathway in CNS Disease: Molecular Mechanisms and Therapeutic Implications

Diseases of the central nervous system (CNS) remain a significant health, social and economic problem around the globe. The development of therapeutic strategies for CNS conditions has suffered due to a poor understanding of the underlying pathologies that manifest them. Understanding common etiological origins at the cellular and molecular level is essential to enhance the development of efficacious and targeted treatment options. Over the years, neuroinflammation has been posited as a common link between multiple neurological, neurodegenerative and neuropsychiatric disorders. Processes that precipitate neuroinflammatory conditions including genetics, infections, physical injury and psychosocial factors, like stress and trauma, closely link dysregulation in kynurenine pathway (KP) of tryptophan metabolism as a possible pathophysiological factor that 'fuel the fire' in CNS diseases. In this study, we aim to review emerging evidence that provide mechanistic insights between different CNS disorders, neuroinflammation and the KP. We provide a thorough overview of the different branches of the KP pertinent to CNS disease pathology that have therapeutic implications for the development of selected and efficacious treatment strategies.

Cesarean section is associated with increased risk of postpartum depressive symptoms in Japan: the Kyushu Okinawa Maternal and Child Health Study

BACKGROUND

The association between cesarean section and the risk of postpartum depressive symptoms remains controversial. The present prebirth cohort study examined this issue in Japan.

METHODS

Study subjects were 1310 women. Information under study was obtained using a self-administered questionnaire. Postpartum depressive symptoms were defined as a total Edinburgh Postnatal Depression Scale score of nine or higher between three and four months postpartum. Multivariate logistic regression analysis was used to adjust for age, body mass index, gestational weeks at baseline, gestational weeks at delivery, number of children at baseline, previous miscarriage or stillbirth, previous abortion, history of depression, family history of depression, region of residence, employment status, educational level, household income, family structure, breastfeeding status, smoking during pregnancy, infant's birthweight, and infant's sex.

RESULTS

Postpartum depressive symptoms were identified in 8.2%. After adjustment for the confounding factors, compared with vaginal delivery, cesarean section was independently associated with an increased risk of postpartum depressive symptoms: the adjusted odds ratio (OR) was 1.95 (95% confidence interval [CI]: 1.16-3.23). This positive association was more apparent among those who had no other children at baseline than among those who already had one or more children: the adjusted ORs were 2.94 (95% CI: 1.35-6.26) and 1.45 (95% CI: 0.68-2.92), respectively; however, this interaction was not significant.

LIMITATIONS

Information on whether each cesarean section was emergency or elective and other obstetric complications was not available.

CONCLUSIONS

Cesarean section may be associated with an increased risk of postpartum depressive symptoms, especially among women without children at baseline.

Profiling of Tryptophan Metabolic Pathways in the Rat Fetoplacental Unit During Gestation

Placental homeostasis of tryptophan is essential for fetal development and programming. The two main metabolic pathways (serotonin and kynurenine) produce bioactive metabolites with immunosuppressive, neurotoxic, or neuroprotective properties and their concentrations in the fetoplacental unit must be tightly regulated throughout gestation. Here, we investigated the expression/function of key enzymes/transporters involved in tryptophan pathways during mid-to-late gestation in rat placenta and fetal organs. Quantitative PCR and heatmap analysis revealed the differential expression of several genes involved in serotonin and kynurenine pathways. To identify the flux of substrates through these pathways, Droplet Digital PCR, western blot, and functional analyses were carried out for the rate-limiting enzymes and transporters. Our findings show that placental tryptophan metabolism to serotonin is crucial in mid-gestation, with a subsequent switch to fetal serotonin synthesis. Concurrently, at term, the close interplay between transporters and metabolizing enzymes of both placenta and fetal organs orchestrates serotonin homeostasis and prevents hyper/hypo-serotonemia. On the other hand, the placental production of kynurenine increases during pregnancy, with a low contribution of fetal organs throughout gestation. Any external insult to this tightly regulated harmony of transporters and enzymes within the fetoplacental unit may affect optimal in utero conditions and have a negative impact on fetal programming.

The role of kynurenine pathway and kynurenic aminotransferase alleles in postpartum depression following cesarean section in Chinese women

OBJECTIVES

A growing body of data indicates that the kynurenine pathway may play a role in the pathogenesis of postpartum depressive symptoms (PDS). Kynurenic aminotransferase (KAT) is an important kynurenine pathway enzyme, catalyzing kynurenine (KYN) into kynurenic acid (KYNA). This study investigated as to whether genetic variations in KAT are associated with PDS.

METHODS

A cohort of 360 Chinese women scheduled to undergo cesarean delivery was enrolled into this study. PDS was determined by an Edinburgh Postnatal Depression Scale (EPDS) score ≥ 13. A total of eight KAT single nucleotide polymorphisms (SNPs) were genotyped and their association with PDS investigated. Serum concentrations of KYN, KYNA, and quinolinic acid (QUIN) in women with or without PDS were also measured. This allowed the determination of the KYNA/KYN ratio, which is reflective of KAT activity.

RESULTS

Postpartum depressive symptoms incidence was 7.2%. Advanced maternal age, lower education, antenatal depression, and postpartum blues were risk factors for PDS (p < .05). Women with PDS, versus non-PDS, had heightened KYN levels one day prior to surgery (ante-d1) (p < .05), as well as having significantly lower KYNA and higher QUIN levels at postnatal day three (post-d3) (p < .05). Women with, versus without, PDS also had a significantly higher QUIN/KYNA ratio at post-d3 (p < .05). KAT activity was significantly lower in women with, versus without, PDS at ante-d3 (p < .05). No significant association was evident between the KAT SNPs and PDS.

CONCLUSION

Our data support a role for alterations in the kynurenine pathway in the pathogenesis of PDS, although no significant association was found for the eight tested KAT SNPs with PDS.

Correlations Between SIRT Genetic Polymorphisms and Postpartum Depressive Symptoms in Chinese Parturients Who Had Undergone Cesarean Section

OBJECTIVE

To investigate the association of genetic polymorphisms of SIRT with postpartum depressive symptoms and analyze the risk factors for postpartum depressive symptoms in women following cesarean section.

METHODS

A total of 368 Chinese woman undergoing cesarean section were enrolled in this study. A cutoff of ≥10 for the Edinburgh Postnatal Depression Scale identified postpartum depressive symptoms. Genotypes of SIRT1, SIRT 2, and SIRT 6 were determined using Sequenom MassArray single-nucleotide polymorphism (SNP) analysis. We analyzed the contribution of genetic factors (SNPs, linkage disequilibrium, and haplotype) to postpartum depressive symptoms and performed logistic regression analysis to identify all potential risk factors for postpartum depressive symptoms and define interactions between genetic and environmental factors.

RESULTS

The incidence of postpartum depressive symptoms was 18.7% in this cohort. Univariate analysis suggested that SIRT2 polymorphism at rs2873703 (TT genotype) and rs4801933 ((TT genotype) and SIRT6 polymorphism at rs350846 (CC genotype) and rs107251 (TT genotype) were significantly correlated with the occurrence of postpartum depressive symptoms (p<0.05). Linkage disequilibrium was identified between SIRT6 polymorphisms rs350846 and rs107251. Incidence of postpartum depressive symptoms in cesarean-section parturients with SIRT2 haplotype CCC was decreased (OR 0.407, 95% CI 0.191-0.867; p=0.016). SIRT2 polymorphisms rs2873703 and rs4801933 were multiply collinear. Logistic regression analysis showed that SIRT2 polymorphism at rs2873703 (TT genotype) and rs4801933 (TT genotype), domestic violence, stress during pregnancy, and depressive prenatal mood were risk factors for postpartum depressive symptoms (p<0.05).

CONCLUSION

Pregnant women with SIRT2 genotypes rs2873703 TT and rs4801933 TT and experiencing domestic violence, stress during pregnancy, and prenatal depression are more likely to suffer from postpartum depressive symptoms.

Dexmedetomidine Alleviates Postpartum Depressive Symptoms following Cesarean Section in Chinese Women: A Randomized Placebo-Controlled Study

OBJECTIVES

Few studies have investigated the prophylactic efficacy of dexmedetomidine (DEX) in postpartum depressive symptoms (PDS). A randomized double-blind placebo-controlled trial was conducted to investigate whether the administration of DEX, immediately after delivery and for patient-controlled intravenous analgesia (PCIA), can attenuate PDS.

METHODS

A total of 600 parturients scheduled for elective cesarean delivery under spinal anesthesia were randomly allocated into the control group (infusion with 0.9% normal saline after delivery and PCIA with sufentanil) and the DEX group (DEX infusion 0.5 μg/kg after delivery and PCIA with DEX plus sufentanil). The prevalence of postpartum depressive disorders was indicated by the Edinburgh Postnatal Depression Scale (EPDS). Postoperative analgesia, sedation, and sleep quality of parturients were also assessed.

RESULTS

Postpartum blues and PDS prevalence in the DEX, versus control, group were significantly lower (5.0% vs 14.1%, p<0.001; 5.7% vs 16.3%, p<0.001, respectively), especially in parturients with antenatal depression or moderate stress during pregnancy. Compared with the control group, the EPDS score at postpartum days 7 and 42 in the DEX group was significantly lower (4.23 ± 4.37 vs 1.93 ± 3.36, p<0.001; 4.68 ± 4.78 vs 1.99 ± 3.18, p<0.001, respectively), as was the incidence of postpartum self-harm ideation at postpartum days 7 and 42 in the DEX group versus the control group (1.1% vs 4.0%, p=0.03; 0.4% vs 2.9%, p=0.04, respectively). The pain score and the sleep quality in the DEX group were better than that in the control group (p<0.001).

CONCLUSION

The application of DEX in the early postpartum period can significantly attenuate the incidence of postpartum depressive disorders.