Intrinsically dysregulated cellular stress signaling genes and gene networks in postpartum depression

Conventional and new immunotherapies for immune system dysregulation in postpartum mood disorders: comparisons to immune system dysregulations in bipolar disorder, major depression, and postpartum autoimmune thyroid disease

INTRODUCTION

Postpartum mood disorders are heterogenous disorders and comprise postpartum psychosis and postpartum depression. Evidence is accumulating that systemic monocyte/macrophage activation, low-grade inflammation and (premature senescence related) T cell defects increase the risk for mood disorders outside pregnancy by affecting the function of microglia and T cells in the emotional brain (the cortico-limbic system) leading to inadequate mood regulation upon stress.

AREAS COVERED

The evidence in the literature that similar immune dysregulations are present in postpartum mood disorders.

RESULTS

The physiological postpartum period is characterized by a rapid T cell surge and a mild activation of the monocyte/macrophage system. Postpartum mood disorder patients show a diminished T cell surge (including that of T regulatory cells) and an increase in low grade inflammation, that is, an increased inflammatory state of monocytes/macrophages and higher levels of serum pro-inflammatory cytokines.

EXPERT OPINION

Anti-inflammatory agents (e.g. COX-2 inhibitors) and T cell boosting agents (e.g. low-dose IL-2 therapy) should be further investigated as treatment. The hypothesis should be investigated that postpartum mood disorders are active episodes (triggered by changes in the postpartum immuno-endocrine milieu) in ongoing, dynamically fluctuating aberrant neuro-immune-endocrine trajectories leading to mood disorders in women (inheritably) vulnerable to these disorders.

The pathophysiology of estrogen in perinatal depression: conceptual update

PURPOSE

Estrogen levels fall sharply after parturition and have long been considered an etiologic contributor to postpartum depression (PPD); however, no differences have been reported in plasma hormone concentrations in people who develop PPD. We examine the question: What is the current view of estrogen and the neurophysiologic processes it impacts in the development and treatment of PPD?

METHODS

A literature review of the role of estrogen on candidate hormonal and epigenetic systems in the peripartum period was performed, including landmark historical studies and recent publications on estrogen-related research. The authors reviewed these papers and participated in reaching consensus on a conceptual framework of estrogen activity within the complexity of pregnancy physiology to examine its potential role for driving novel interventions.

RESULTS

Estrogen fluctuations must be conceptualized in the context of multiple dramatic and interacting changes inherent in pregnancy and after birth, including progesterone, corticosteroids, inflammation, circadian biology and psychosocial challenges. Individuals who develop PPD have increased sensitivity to epigenetic alteration at estrogen-responsive genes, and these changes are highly predictive of PPD. An effective estrogen-based treatment for PPD has yet to be found, but interventions focused on associated inflammation and circadian rhythms are promising.

CONCLUSIONS

Our understanding of the biological basis of PPD, one of the most common morbidities of the perinatal period, is expanding beyond changes in gynecologic hormone concentrations to include their impact on other systems. This growing understanding of the many processes influencing PPD will allow for the development of novel prevention and treatment strategies.

Estradiol and progesterone from pregnancy to postpartum: a longitudinal latent class analysis

Introduction

During the peripartum, women undergo significant hormonal changes that are crucial for fetal development and a healthy pregnancy and postpartum period for mother and infant. Although several studies have determined healthy norm ranges of estradiol and progesterone, there are discrepancies among the reports, rendering it unclear which hormone levels are linked to adverse health outcomes. To account for the impact of sex steroid patterns on health outcomes in mothers and children, a longitudinal assessment of different parameters is needed.

Materials and methods

We longitudinally assessed a cohort of 130 women over five months during pregnancy and postpartum. The women provided saliva samples and completed psychosocial questionnaires. Hormone analyses were conducted using enzyme-linked immunosorbent assay (ELISA). Different parameters of estradiol and progesterone were analyzed and evaluated in relation to psychometric variables. To examine the presence of heterogenous hormonal trajectories in the peripartum, we applied group-based trajectory modelling as a special case of latent-class group analysis.

Results

Estradiol and progesterone levels rose towards the end of pregnancy and dropped sharply after birth, with considerable individual variation, particularly during pregnancy. However, their ratio remained stable. We identified three estradiol trajectory subgroups and two progesterone subgroups. Age influenced progesterone levels, with older pregnant women having higher levels than younger women. Anxiety and depressive symptoms had a predictive value for trajectories of specific subgroups of women. The study also revealed two distinct subgroups regarding the course of estradiol and progesterone fluctuations as well as their ratio.

Conclusion

This study provides insights into the course and fluctuation of salivary estradiol and progesterone levels among healthy women during the peripartum period, highlighting significant variations in hormone levels but stability in their ratio during this time. The finding of distinct sex steroid courses in the peripartum is new and suggests the need for further research to explore their impact on health outcomes. Our preliminary results suggest that hormonal fluctuations at the end of pregnancy appear to be a normal occurrence and might even be a protective factor for associated psychological symptoms and sleep disturbances in women.

tiRNA-Gly-GCC-001 in major depressive disorder: Promising diagnostic and therapeutic biomarker

BACKGROUND AND PURPOSE

In major depressive disorder (MDD), exploration of biomarkers will be helpful in diagnosing the disorder as well as in choosing a treatment and predicting the treatment response. Currently, tRNA-derived small ribonucleic acids (tsRNAs) have been established as promising non-invasive biomarker candidates that may enable a more reliable diagnosis or monitoring of various diseases. Herein, we aimed to explore tsRNA expression together with functional activities in MDD development.

EXPERIMENTAL APPROACH

Serum samples were obtained from patients with MDD and healthy controls, and small RNA sequencing (RNA-Seq) was used to profile tsRNA expression. Dysregulated tsRNAs in MDD were validated by quantitative real-time polymerase chain reaction (qRT-PCR). The diagnostic utility of specific tsRNAs and the expression of these tsRNAs after antidepressant treatment were analysed.

KEY RESULTS

In total, 38 tsRNAs were significantly differentially expressed in MDD samples relative to healthy individuals (34 up-regulated and 4 down-regulated). qRT-PCR was used to validate the expression of six tsRNAs that were up-regulated in MDD (tiRNA-1:20-chrM.Ser-GCT, tiRNA-1:33-Gly-GCC-1, tRF-1:22-chrM.Ser-GCT, tRF-1:31-Ala-AGC-4-M6, tRF-1:31-Pro-TGG-2 and tRF-1:32-chrM.Gln-TTG). Interestingly, serum tiRNA-Gly-GCC-001 levels exhibited an area under the ROC curve of 0.844. Moreover, tiRNA-Gly-GCC-001 is predicted to suppress brain-derived neurotrophic factor (BDNF) expression. Furthermore, significant tiRNA-Gly-GCC-001 down-regulation was evident following an 8-week treatment course and served as a promising baseline predictor of patient response to antidepressant therapy.

CONCLUSION AND IMPLICATIONS

Our current work reports for the first time that tiRNA-Gly-GCC-001 is a promising MDD biomarker candidate that can predict patient responses to antidepressant therapy.

Temporal dynamics of neurobehavioral hormone sensitivity in a scaled-down experimental model of early pregnancy and parturition

The hormonal changes of pregnancy and parturition can trigger robust changes in affective state, particularly among patients with a history of postpartum depression. However, more work is needed to elucidate the temporal dynamics of symptom emergence. The current study explored how quickly hormone-sensitive (HS+) individuals can be differentiated from hormone-insensitive (HS-) controls in the context of a tightly controlled experimental hormone manipulation, and which symptoms demonstrate the most rapid, consistent, and largest response during this protocol. Participants were female, non-pregnant, and euthymic, with a history of DSM-5 major depressive episode with peripartum onset (n = 15) or parous healthy controls with no psychiatric history (n = 15). Perinatal hormonal changes were simulated by inducing hypogonadism, adding back estradiol (E2) and progesterone (P4) to reach first-trimester levels for 8 weeks, and then subsequently withdrawing both hormones. Those reporting a 30% or greater increase during addback or withdrawal on select subscales of the Inventory of Depression and Anxiety Symptoms (IDAS) were identified as HS+. Participants provided daily ratings of symptoms throughout the study via the Daily Record of Severity of Problems. Results indicated that HS+ participants could be differentiated from HS- participants early in the hormone protocol, with many symptoms showing significantly greater change from baseline within the first week of addback. Notably, the most rapid symptom increases were observed for Anger/Irritability, Mood Swings, Overwhelm, Lethargy, Increased Appetite, Joint and Muscle Pain, and Breast Tenderness, reaching 50% of peak group contrast within the first week of hormone addback. The largest group effects were observed for Anger/Irritability, followed by Fatigue and Anxiety, and the most consistent group effects were observed for Anger/Irritability, Interpersonal Conflict, Overwhelm, and Hopelessness. Findings support the role of reproductive hormones in the onset of perinatal affective disorders. The rapid emergence of anger and irritability in HS+ participants suggests that these symptoms may be early indicators of perinatal hormone sensitivity.

A Common Genetic Factor Underlies Genetic Risk for Gynaecological and Reproductive Disorders and Is Correlated with Risk to Depression

INTRODUCTION

Sex steroid hormone fluctuations may underlie both reproductive disorders and sex differences in lifetime depression prevalence. Previous studies report high comorbidity among reproductive disorders and between reproductive disorders and depression. This study sought to assess the multivariate genetic architecture of reproductive disorders and their loading onto a common genetic factor and investigated whether this latent factor shares a common genetic architecture with female depression, including perinatal depression (PND).

METHOD

Using UK Biobank and FinnGen data, genome-wide association meta-analyses were conducted for nine reproductive disorders, and genetic correlation between disorders was estimated. Genomic Structural Equation Modelling identified a latent genetic factor underlying disorders, accounting for their significant genetic correlations. SNPs significantly associated with both latent factor and depression were identified.

RESULTS

Excellent model fit existed between a latent factor underlying five reproductive disorders (χ2 (5) = 6.4; AIC = 26.4; CFI = 1.00; SRMR = 0.03) with high standardised loadings for menorrhagia (0.96, SE = 0.05); ovarian cysts (0.94, SE = 0.05); endometriosis (0.83, SE = 0.05); menopausal symptoms (0.77, SE = 0.10); and uterine fibroids (0.65, SE = 0.05). This latent factor was genetically correlated with PND (rG = 0.37, SE = 0.15, p = 1.4e-03), depression in females only (rG = 0.48, SE = 0.06, p = 7.2e-11), and depression in both males and females (MD) (rG = 0.35, SE = 0.03, p = 1.8e-30), with its top locus associated with FSHB/ARL14EP (rs11031006; p = 9.1e-33). SNPs intronic to ESR1, significantly associated with the latent factor, were also associated with PND, female depression, and MD.

CONCLUSION

A common genetic factor, correlated with depression, underlies risk of reproductive disorders, with implications for aetiology and treatment. Genetic variation in ESR1 is associated with reproductive disorders and depression, highlighting the importance of oestrogen signalling for both reproductive and mental health.

Divergent Transcriptomic Effects of Allopregnanolone in Postpartum Depression

Brexanolone, a formulation of the neurosteroid allopregnanolone (ALLO), is approved for treating postpartum depression (PPD) and is being investigated for therapeutic efficacy across numerous neuropsychiatric disorders. Given ALLO's beneficial effects on mood in women with PPD compared to healthy control women, we sought to characterize and compare the cellular response to ALLO in women with (n = 9) or without (n = 10, i.e., Controls) past PPD, utilizing our previously established patient-derived lymphoblastoid cell lines (LCLs). To mimic in vivo PPD ALLO-treatment, LCLs were exposed to ALLO or DMSO vehicle for 60 h and RNA-sequenced to detect differentially expressed genes (DEGs, pnominal < 0.05). Between ALLO-treated Control and PPD LCLs, 269 DEGs were identified, including Glutamate Decarboxylase 1 (GAD1), which was decreased 2-fold in PPD. Network analysis of PPD:ALLO DEGs revealed enriched terms related to synaptic activity and cholesterol biosynthesis. Within-diagnosis analyses (i.e., DMSO vs. ALLO) detected 265 ALLO-induced DEGs in Control LCLs compared to only 98 within PPD LCLs, with just 11 DEGs overlapping. Likewise, the gene ontologies underlying ALLO-induced DEGs in PPD and Control LCLs were divergent. These data suggest that ALLO may activate unique and opposing molecular pathways in women with PPD, which may be tied to its antidepressant mechanism.