HPA-axis multilocus genetic profile score moderates the association between maternal prenatal perceived stress and offspring depression in early adulthood

Polygene by environment interactions predicting depressive outcomes

Depression is a major public health problem with a continued need to uncover its etiology. Current models of depression contend that gene-by-environment (G × E) interactions influence depression risk, and further, that depression is polygenic. Thus, recent models have emphasized two polygenic approaches: a hypothesis-driven multilocus genetic profile score (MGPS; "MGPS × E") and a polygenic risk score (PRS; "PRS × E") derived from genome-wide association studies (GWAS). This review for the first time synthesizes current knowledge on polygene by environment "P × E" interaction research predicting primarily depression-related outcomes, and in brief, neurobiological outcomes. The "environment" of focus in this project is stressful life events. It further discusses findings in the context of differential susceptibility and diathesis-stress theories-two major theories guiding G × E work. This synthesis indicates that, within the MGPS literature, polygenic scores based on the serotonin system, the HPA axis, or across multiple systems, interact with environmental stress exposure to predict outcomes at multiple levels of analyses and most consistently align with differential susceptibility theory. Depressive outcomes are the most studied, but neuroendocrine, and neuroimaging findings are observed as well. By contrast, vast methodological differences between GWAS-based PRS studies contribute to mixed findings that yield inconclusive results.

Ethical Concerns about Fashionable Dog Breeding

The historical relationship between humans and dogs has involved selective breeding for various purposes, such as hunting, guarding, and service roles. However, over time, there has been a shift in preferences from functionality to aesthetics, which has influenced the diverse sizes, shapes, and coats of dog breeds. This review looks at fashionable dog breeding and questions the ethics of prioritising looks over health and behaviour. It aims to alert potential owners, breeders, and regulators to the importance of considering a dog's overall well-being, not just its appearance, which has resulted in fad breeding, leading to genetic disorders, health issues, and a loss of biodiversity. Ethical concerns arise from breeding brachycephalic breeds with respiratory conditions, inbreeding causing inherited disorders, and overbreeding popular breeds while shelter dogs remain unadopted. Additionally, the impact of cosmetic surgeries on popular dog breeds, as well as the neglect of behavioural traits in favour of physical characteristics and strict breeding practices are also considered. The current breeding model can have a negative impact on the emotional and cognitive well-being of dogs, resulting in issues such as aggression, anxiety, and other behavioural problems that can significantly reduce their overall quality of life. Unregulated breeding practices and the demand for rare breeds can lead to illegal breeding, compromising animal welfare. Prospective owners, veterinarians, kennel clubs, and legislators all need to play a responsible role in protecting animals.

The effects of childhood maltreatment, recent interpersonal and noninterpersonal stress, and HPA-axis multilocus genetic variation on prospective changes in adolescent depressive symptoms: A multiwave longitudinal study

Based on a multiwave, two-year prospective design, this study is the first to examine the extent to which multilocus hypothalamic-pituitary-adrenal axis (HPA axis)-related genetic variants, childhood maltreatment, and recent stress jointly predicted prospective changes in adolescent depressive symptoms. A theory-driven multilocus genetic profile score (MGPS) was calculated to combine the effects of six common polymorphisms within HPA-axis related genes (CRHR1, NR3C1, NR3C2, FKBP5, COMT, and HTR1A) in a sample of Chinese Han adolescents (N = 827; 50.2% boys; Mage = 16.45 ± 1.36 years). The results showed that the three-way interaction of HPA-axis related MGPS, childhood maltreatment and recent interpersonal, but not noninterpersonal, stress significantly predicted prospective changes in adolescent depressive symptoms. For adolescents with high but not low HPA-axis related MGPS, exposure to severe childhood maltreatment predisposed individuals more vulnerable to recent interpersonal stress, exhibiting greater prospective changes in adolescent depressive symptoms. The findings provide preliminary evidence for the cumulative risk mechanism regarding gene-by-environment-by-environment (G × E1 × E2) interactions that underlie the longitudinal development of adolescent depressive symptoms and show effects specific to interpersonal stress.

The microbiota-gut-brain axis and perceived stress in the perinatal period

Perinatal perceived stress can contribute to worse health outcomes for the parent-child dyad. Given the emerging relationship between the microbiota-gut-brain axis and stress, this study sought to elucidate connections between bowel symptoms and the gut microbiome in relation to perceived stress at three time points in the perinatal period: two during pregnancy and one postpartum. Ninety-five pregnant individuals participated in a prospective cohort study from April 2017 to November 2019. Researchers assessed Perceived Stress Scale-10 (PSS); bowel symptoms (according to the IBS Questionnaire); psychiatrist assessment of new onset or exacerbated depression and anxiety; and fecal samples analyzed for alpha diversity (measures of gut microbiome diversity utilizing Shannon, Observed OTUs, and Faith's PD) at each timepoint. Covariates included weeks of gestation and weeks postpartum. PSS scores were divided into "Perceived Self-Efficacy" and "Perceived Helplessness." Increased gut microbial diversity was associated with decreased bowel symptoms, decreased overall perceived stress, increased ability to cope with adversity, and decreased distress in the postpartum period. This study found a significant association between a less diverse microbial community, lower self-efficacy early in pregnancy, and greater bowel symptoms and perceived helplessness later in the perinatal period, relationships that may ultimately point to novel diagnostic methods and interventions for perceived stress based on the microbiota-gut-brain axis.

DNA methylation in regulatory elements of the FKBP5 and NR3C1 gene in mother-child binomials with depression

BACKGROUND

The FKBP5 and NR3C1 genes play an important role in stress response, thus impacting mental health. Stress factor exposure in early life, such as maternal depression, may contribute to epigenetic modifications in stress response genes, increasing the susceptibility to different psychopathologies. The present study aimed to evaluate the DNA methylation profile in maternal-infant depression in regulatory regions of the FKBP5 gene and the alternative promoter of the NR3C1 gene.

METHODS

We evaluated 60 mother-infant pairs. The levels of DNA methylation were analyzed by the MSRED-qPCR technique.

RESULTS

We observed an increased DNA methylation profile in the NR3C1 gene promoter in children with depression and children exposed to maternal depression (p < 0.05). In addition, we observed a correlation of DNA methylation between mothers and offspring exposed to maternal depression. This correlation shows a possible intergenerational effect of maternal MDD exposure on the offspring. For FKBP5, we found a decrease in DNA methylation at intron 7 in children exposed to maternal MDD during pregnancy and a correlation of DNA methylation between mothers and children exposed to maternal MDD (p < 0.05).

LIMITATIONS

Although the individuals of this study are a rare group, the sample size of the study was small, and we evaluated the DNA methylation of only one CpG site for each region.

CONCLUSION

These results indicate changes in DNA methylation levels in regulatory regions of FKBP5 and NR3C1 in the mother-child MDD context and represent a potential target of studies to understand the depression etiology and how it occurs between generations.

Psychological legacies of intergenerational trauma under South African apartheid: Prenatal stress predicts greater vulnerability to the psychological impacts of future stress exposure during late adolescence and early adulthood in Soweto, South Africa

BACKGROUND

South Africa's rates of psychiatric morbidity are among the highest in sub-Saharan Africa and are foregrounded by the country's long history of political violence during apartheid. Growing evidence suggests that in utero stress exposure is a potent developmental risk factor for future mental illness risk, yet the extent to which the psychiatric effects of prenatal stress impact the next generation are unknown. We evaluate the intergenerational effects of prenatal stress experienced during apartheid on psychiatric morbidity among children at ages 17-18 and also assess the moderating effects of maternal age, social support, and past household adversity.

METHODS

Participants come from Birth-to-Twenty, a longitudinal birth cohort study in Soweto-Johannesburg, South Africa's largest peri-urban township which was the epicentre of violent repression and resistance during the final years of the apartheid regime. Pregnant women were prospectively enrolled in 1990 and completed questionnaires assessing social experiences, and their children's psychiatric morbidity were assessed at ages 17-18.

RESULTS

Full data were available from 304 mother-child pairs in 2007-8. Maternal prenatal stress in 1990 was not directly associated greater psychiatric morbidity during at ages 17-18. Maternal age and past household adversity moderated the intergenerational mental health effects of prenatal stress such that children born to younger mothers and late adolescent/young adult children experiencing greater household adversity exhibited worse psychiatric morbidity at ages 17-18. Social support did not buffer against the long-term psychiatric impacts of prenatal stress.

CONCLUSIONS

Greater prenatal stress from apartheid predicted adverse psychiatric outcomes among children born to younger mothers and adolescents/young adults who experienced greater concurrent stress. Our findings suggest that prenatal stress may affect adolescent mental health, have stress-sensitising effects, and represent possible intergenerational effects of trauma experienced under apartheid in this sample.

Hypothalamic-pituitary-adrenal Axis Multilocus Genetic Variation, Childhood Parenting and Adolescent Anxiety Symptoms: Evidence of Cumulative Polygenic Plasticity

Research suggests that genetic variants that regulate the hypothalamic-pituitary-adrenal (HPA) axis function moderate the association between parenting and anxiety symptoms, but these studies have primarily focused on (i) individual genes with very small and unreliable effect and (ii) the role of mothers as opposed to fathers. Using a multilocus genetic profile score approach, the current study is the first to examine the moderation effect of HPA-axis multilocus genetic variants on the associations of both maternal and paternal parenting with adolescent anxiety symptoms. In a sample of Chinese Han adolescents (N = 772; 50.1% girls; M_age = 16.48 ± 1.40 years, range: 15-20 years), a theory-driven multilocus genetic profile score was computed by counting the numbers of alleles that were previously linked to heightened stress reactivity in six HPA-axis related genes. This HPA-axis related multilocus genetic profile score equivalently interacted with both maternal and paternal parenting in the prediction of adolescent anxiety symptoms. Consistent with cumulative polygenic plasticity hypothesis of differential susceptibility model, adolescents with more versus low alleles linked to heightened stress reactivity not only suffered more from poor maternal or paternal parenting quality, but also benefited more from high maternal or paternal parenting quality. However, none of the individual HPA-axis genes within this multilocus genetic profile score yielded a significant gene-by-environment (G × E) interaction when examined in isolation. The findings survived after internal replication analysis and a novel, valid influence statistic DFBETAS analysis, demonstrating the robustness of the results. The current study highlights the potential value of using a multilocus approach to understand G × E effects underlying anxiety symptoms and emphasizes the role of both mothers and fathers in such gene-parenting interactions, especially in Chinese families.

Childhood parenting and adolescent internalizing and externalizing symptoms: Moderation by multilocus hypothalamic-pituitary-adrenal axis-related genetic variation

Genetic variants that regulate hypothalamic-pituitary-adrenal (HPA) axis function have been demonstrated to moderate the association between parenting and mental health. However, extant research has focused primarily on (i) effects of individual genes or (ii) maternal as opposed to paternal parenting. Using a multilocus genetic profile score (MGPS) approach, the current study is the first to examine the moderation effect of multilocus HPA-axis related genetic variants on the association of both maternal and paternal parenting with adolescent internalizing and externalizing symptoms. In a sample of 772 Chinese Han adolescents (Mage = 16.48 ± 1.40 years; 50.1% girls), a theory-driven MGPS was calculated using six polymorphisms within HPA-axis related genes (CRHR1, NR3C1, NR3C2, FKBP5, COMT, and HT1RA). Results showed that the MGPS interacted with both maternal and paternal parenting in the association with adolescent internalizing symptoms, but not externalizing symptoms. Consistent with the differential susceptibility model, adolescents with high versus low MGPS exhibited not only more internalizing symptoms when exposed to low quality of parenting but also less internalizing symptoms when exposed to high quality of parenting. The current findings highlight the potential value of using a multilocus approach to understanding gene-by-environment interaction (G×E) effects underlying mental health. Within such G×E effects, not only maternal but also paternal parenting should be addressed.

Gaining a deeper understanding of social determinants of preterm birth by integrating multi-omics data

In the US, high rates of preterm birth (PTB) and profound Black-White disparities in PTB have persisted for decades. This review focuses on the role of social determinants of health (SDH), with an emphasis on maternal stress, in PTB disparity and biological embedding. It covers: (1) PTB disparity in US Black women and possible contributors; (2) the role of SDH, highlighting maternal stress, in the persistent racial disparity of PTB; (3) epigenetics at the interface between genes and environment; (4) the role of the genome in modifying maternal stress-PTB associations; (5) recent advances in multi-omics studies of PTB; and (6) future perspectives on integrating multi-omics with SDH to elucidate the Black-White disparity in PTB. Available studies have indicated that neither environmental exposures nor genetics alone can adequately explain the Black-White PTB disparity. Preliminary yet promising findings of epigenetic and gene-environment interaction studies underscore the value of integrating SDH with multi-omics in prospective birth cohort studies, especially among high-risk Black women. In an era of rapid advancements in biomedical sciences and technologies and a growing number of prospective birth cohort studies, we have unprecedented opportunities to advance this field and finally address the long history of health disparities in PTB. IMPACT: This review provides an overview of social determinants of health (SDH) with a focus on maternal stress and its role on Black-White disparity in preterm birth (PTB). It summarizes the available literature on the interplay of maternal stress with key biological layers (e.g., individual genome and epigenome in response to environmental stressors) and significant knowledge gaps. It offers perspectives that such knowledge may provide deeper insight into how SDH affects PTB and why some women are more vulnerable than others and underscores the critical need for integrating SDH with multi-omics in prospective birth cohort studies, especially among high-risk Black women.

Three phases of Gene × Environment interaction research: Theoretical assumptions underlying gene selection

Some Gene × Environment interaction (G×E) research has focused upon single candidate genes, whereas other related work has targeted multiple genes (e.g., polygenic scores). Each approach has informed efforts to identify individuals who are either especially vulnerable to the negative effects of contextual adversity (diathesis stress) or especially susceptible to both positive and negative contextual conditions (differential susceptibility). A critical step in all such molecular G×E research is the selection of genetic variants thought to moderate environmental influences, a subject that has not received a great deal of attention in critiques of G×E research (beyond the observation of small effects of individual genes). Here we conceptually distinguish three phases of G×E work based on the selection of genes presumed to moderate environmental effects and the theoretical basis of such decisions: (a) single candidate genes, (b) composited (multiple) candidate genes, and (c) GWAS-derived polygenic scores. This illustrative, not exhaustive, review makes it clear that implicit or explicit theoretical assumptions inform gene selection in ways that have not been clearly articulated or fully appreciated.