Data-driven discovery of mid-pregnancy immune markers associated with maternal lifetime stress: results from an urban pre-birth cohort

Psychosocial stress and associations with inflammation in mid-gestation maternal, fetal, and placental tissue

BACKGROUND

Inflammation has been implicated as an intermediary between psychosocial stress and adverse birth outcomes. However, prior work has mostly relied on maternal inflammation as a proxy for fetal inflammation mid-gestation or measured fetal inflammation in cord blood and placenta obtained at delivery. No studies have examined psychosocial stress in relation to fetal inflammation mid-gestation.

METHODS

Twenty cytokines were measured in matched maternal blood, cord blood, and placenta obtained mid-gestation from a socio-demographically diverse group of pregnant participants undergoing elective second-trimester pregnancy terminations (N = 106). Corticotropin-releasing hormone, a proposed biomarker of gestational length, was measured in maternal blood. Perceived stress, and exposure to stressful life events, job strain, and social support were measured via questionnaires. We used linear regression to estimate associations between individual stressors and inflammatory biomarkers in each biomatrix and principal component analysis to assess groups of inflammatory biomarkers.

RESULTS

We observed many matrix-specific associations between psychosocial stressors and inflammatory biomarkers. For example, low versus high social support was associated with significantly decreased levels of maternal blood CCL3 (β=-0.53; 95 % confidence interval [CI]=-0.98,-0.07), CCL4 (β=-0.26; 95 % CI=-0.47,-0.04), IL8 (β=-0.79; 95 % CI=-1.47,-0.11), CXCL9 (β=-0.47; 95 % CI=-0.89,-0.06), IFNγ (β=-2.28; 95 % CI=-3.60,-0.96), IL4 (β=-1.07; 95 % CI=-1.88,-0.26); and cord blood IFNγ (β=-0.83; 95 % CI=-1.52,-0.14). Social support was not associated with placental inflammation.

CONCLUSIONS

During mid-pregnancy, psychosocial stress─ particularly low social support─ was associated with maternal blood levels of select cytokines, suggesting a potential pathway linking social stress and inflammation. Our results indicate that the placenta may buffer these inflammatory effects on the fetus.

Cumulative maternal lifetime stress & child asthma: effect modification by BMI

BACKGROUND

Investigations of maternal psychosocial stress and child asthma have produced mixed findings, which may reflect inconsistent consideration of modifying factors.

OBJECTIVE

To examine associations between maternal lifetime stress and child asthma, and to assess effect modification by maternal pre-pregnancy body mass index and race/ethnicity in a prenatal cohort of mother-child dyads.

METHODS

Maternal lifetime stress was assessed using the Life Stressor Checklist-Revised, administered during pregnancy and child asthma was ascertained by parent-report in study follow-up visits. In the overall group and stratified by race/ethnicity, we used multivariable logistic regression and varying coefficient modeling to investigate the association between maternal stress and child asthma, assessing for effect modification by pre-pregnancy body mass index.

RESULTS

Women were predominately Black (Black/Hispanic-Black 44.5%) or non-Black Hispanic (37.6%), with elevated pre-pregnancy body mass index (25.1% overweight, 29.8% obese); 17% of children had asthma. Higher maternal stress was associated with increased relative odds of child asthma only in dyads with women in the obese (≥30 kilograms/meters squared) category (odds ratio 1.84, 95% confidence interval 1.27-2.67). Varying coefficient models demonstrated stronger positive associations between increased maternal lifetime stress and child asthma in women with higher pre-pregnancy body mass index; the strongest association was observed in the Black group.

CONCLUSION

Maternal pre-pregnancy body mass index modified the association between maternal lifetime stress and child asthma. These findings underscore the need to consider complex interactions to fully elucidate intergenerational stress effects on early childhood asthma.

Maternal steroids during pregnancy and their associations with exposure to lifetime stressful life events, prenatal stress appraisal and psychological functioning

BACKGROUND

During pregnancy, steroids enable physiological adaptations in response to many factors, including maternal stress or psychological functioning. While stress and psychological dysfunction can have endocrine-disrupting effects beyond cortisol disruption, associations between prenatal maternal stress or related psychological dysfunction and the broader steroid milieu remain understudied.

AIM

To assess associations between independent and joint maternal stress and psychological functioning measures and steroid profiles in pregnancy (22-40 gestational weeks) in the Programming of Intergenerational Stress Mechanisms (PRISM) birth cohort (n = 334).

METHODS

Serum metabolomics detected 42 steroids and their metabolites, which were grouped into five classes (pregnenolone, androgens, estrogens, progestin, and corticosteroids). The Perceived Stress Scale, Life Stressor Checklist-Revised, and Edinburgh Postnatal Depression Scale indexed lifetime traumatic/non-traumatic stressors, global prenatal stress appraisal, and depressive symptoms during pregnancy, respectively. Exposures were categorized as high-low using the corresponding 3rd quartiles. We assessed associations between both individual and joint stress exposures with steroid classes using linear mixed effect models and with individual steroids using linear regressions. We also examined fetal sex-specific effects.

RESULTS

High prenatal perceived stress was independently associated with lower levels of androgens and estrogens in the overall sample [β (95%CI): androgens: -0.13 (-0.25;-0.01); estrogens: -0.16 (-0.31;-0.01)], particularly among women carrying males [androgens: -0.22 (-0.39;-0.05); estrogens: -0.28 (-0.50;-0.07)]. Results on estrogens were consistent when considering joint exposure to both greater lifetime stressors and higher prenatal perceived stress. We also found a single testosterone metabolite-5alpha-androstan-3alpha,17alpha-diol disulfate-negatively associated with both individual high perceived stress and joint exposure to high lifetime stressors and high perceived stress among women carrying males.

CONCLUSIONS

Increased maternal perceived stress experienced in pregnancy was independently associated with lower maternal androgen and estrogen levels during pregnancy in the overall sample, particularly among women carrying males. Results on estrogens were consistent when we considered the joint exposure of increased lifetime stressors and higher prenatal perceived stress.

Type 2 Cystatins and Their Roles in the Regulation of Human Immune Response and Cancer Progression

Cystatins are a family of intracellular and extracellular protease inhibitors that inhibit cysteine cathepsins-a group of lysosomal cysteine proteases that participate in multiple biological processes, including protein degradation and post-translational cleavage. Cysteine cathepsins are associated with the development of autoimmune diseases, tumor progression, and metastasis. Cystatins are categorized into three subfamilies: type 1, type 2, and type 3. The type 2 cystatin subfamily is the largest, containing 10 members, and consists entirely of small secreted proteins. Although type 2 cystatins have many shared biological roles, each member differs in structure, post-translational modifications (e.g., glycosylation), and expression in different cell types. These distinctions allow the type 2 cystatins to have unique biological functions and properties. This review provides an overview of type 2 cystatins, including their biological similarities and differences, their regulatory effect on human immune responses, and their roles in tumor progression, immune evasion, and metastasis.

The Exposome Approach to Decipher the Role of Multiple Environmental and Lifestyle Determinants in Asthma

Asthma is a widespread respiratory disease caused by complex contribution from genetic, environmental and behavioral factors. For several decades, its sensitivity to environmental factors has been investigated in single exposure (or single family of exposures) studies, which might be a narrow approach to tackle the etiology of such a complex multifactorial disease. The emergence of the exposome concept, introduced by C. Wild (2005), offers an alternative to address exposure-health associations. After presenting an overview of the exposome concept, we discuss different statistical approaches used to study the exposome-health associations and review recent studies linking multiple families of exposures to asthma-related outcomes. The few studies published so far on the association between the exposome and asthma-related outcomes showed differences in terms of study design, population, exposome definition and statistical methods used, making their results difficult to compare. Regarding statistical methods, most studies applied successively univariate (Exposome-Wide Association Study (ExWAS)) and multivariate (adjusted for co-exposures) (e.g., Deletion-Substitution-Addition (DSA) algorithm) regression-based models. This latest approach makes it possible to assess associations between a large set of exposures and asthma outcomes. However, it cannot address complex interactions (i.e., of order ≥3) or mixture effects. Other approaches like cluster-based analyses, that lead to the identification of specific profiles of exposure at risk for the studied health-outcome, or mediation analyses, that allow the integration of information from intermediate biological layers, could offer a new avenue in the understanding of the environment-asthma association. European projects focusing on the exposome research have recently been launched and should provide new results to help fill the gap that currently exists in our understanding of the effect of environment on respiratory health.