Perinatal protein malnutrition results in genome-wide disruptions of 5-hydroxymethylcytosine at regions that can be restored to control levels by an enriched environment

New Evidence for the Role of the Blood-Brain Barrier and Inflammation in Stress-Associated Depression: A Gene-Environment Analysis Covering 19,296 Genes in 109,360 Humans

Mounting evidence supports the key role of the disrupted integrity of the blood-brain barrier (BBB) in stress- and inflammation-associated depression. We assumed that variations in genes regulating the expression and coding proteins constructing and maintaining this barrier, along with those involved in inflammation, have a predisposing or protecting role in the development of depressive symptoms after experiencing severe stress. To prove this, genome-by-environment (GxE) interaction analyses were conducted on 6.26 M SNPS covering 19,296 genes on PHQ9 depression in interaction with adult traumatic events scores in the UK Biobank (n = 109,360) in a hypothesis-free setup. Among the 63 genes that were significant in stress-connected depression, 17 were associated with BBB, 23 with inflammatory processes, and 4 with neuroticism. Compared to all genes, the enrichment of significant BBB-associated hits was 3.82, and those of inflammation-associated hits were 1.59. Besides some sex differences, CSMD1 and PTPRD, encoding proteins taking part in BBB integrity, were the most significant hits in both males and females. In conclusion, the identified risk genes and their encoded proteins could provide biomarkers or new drug targets to promote BBB integrity and thus prevent or decrease stress- and inflammation-associated depressive symptoms, and possibly infection, e.g., COVID-19-associated mental and neurological symptoms.

Perinatal protein malnutrition alters maternal behavior and leads to maladaptive stress response, neurodevelopmental delay and disruption on DNA methylation machinery in female mice offspring

Deficiencies in maternal nutrition have long-term consequences affecting brain development of the progeny and its behavior. In the present work, female mice were exposed to a normal-protein or a low-protein diet during gestation and lactation. We analyzed behavioral and molecular consequences of malnutrition in dams and how it affects female offspring at weaning. We have observed that a low-protein diet during pregnancy and lactation leads to anxiety-like behavior and anhedonia in dams. Protein malnutrition during the perinatal period delays physical and neurological development of female pups. Glucocorticoid levels increased in the plasma of malnourished female offspring but not in dams when compared to the control group. Interestingly, the expression of glucocorticoid receptor (GR) was reduced in hippocampus and amygdala on both malnourished dams and female pups. In addition, malnourished pups exhibited a significant increase in the expression of Dnmt3b, Gadd45b, and Fkbp5 and a reduction in Bdnf VI variant mRNA in hippocampus. In contrast, a reduction on Dnmt3b has been observed on the amygdala of weaned mice. No changes have been observed on global methylation levels (5-methylcytosine) in hippocampal genomic DNA neither in dams nor female offspring. In conclusion, deregulated behaviors observed in malnourished dams might be mediated by a low expression of GR in brain regions associated with emotive behaviors. Additionally, low-protein diet differentially deregulates the expression of genes involved in DNA methylation/demethylation machinery in female offspring but not in dams, providing an insight into regional- and age-specific mechanisms due to protein malnutrition.

Epigenetic mechanisms linking early-life adversities and mental health

Early-life adversities, whether prenatal or postnatal exposure, have been linked to adverse mental health outcomes later in life increasing the risk of several psychiatric disorders. Research on its neurobiological consequences demonstrated an association between exposure to adversities and persistent alterations in the structure, function, and connectivity of the brain. Consistent evidence supports the idea that regulation of gene expression through epigenetic mechanisms are involved in embedding the impact of early-life experiences in the genome and mediate between social environments and later behavioral phenotypes. In addition, studies from rodent models and humans suggest that these experiences and the acquired risk factors can be transmitted through epigenetic mechanisms to offspring and the following generations potentially contributing to a cycle of disease or disease risk. However, one of the important aspects of epigenetic mechanisms, unlike genetic sequences that are fixed and unchangeable, is that although the epigenetic markings are long-lasting, they are nevertheless potentially reversible. In this review, we summarize our current understanding of the epigenetic mechanisms involved in the mental health consequences derived from early-life exposure to malnutrition, maltreatment and poverty, adversities with huge and pervasive impact on mental health. We also discuss the evidence about transgenerational epigenetic inheritance in mammals and experimental data suggesting that suitable social and pharmacological interventions could reverse adverse epigenetic modifications induced by early-life negative social experiences. In this regard, these studies must be accompanied by efforts to determine the causes that promote these adversities and that result in health inequity in the population.

Association of Parental Famine Exposure With Offspring Depression and Cognition Function

BACKGROUND

The effect of early exposure to famine on depression and cognition in adulthood has been shown, but the intergenerational association of famine remain to be explored. This study focused on exploring the association of parental famine exposure with depression and cognition in the offspring.

METHODS

Based on the Chinese Family Panel Studies database, which is a longitudinal survey, we included 5,150 individuals born between 1959 and 1961 and divided them into fetal-exposed, infancy-exposed (birth year = 1957-1958), school-age-exposed (birth year = 1949-1956), adolescent-exposed (birth year = 1946-1948), and unexposed groups. We used one-way analysis of variance, multiple linear regression, and one follow-up measurement to analyze the association between parental famine exposure and offspring depression and cognitive function.

RESULTS

Compared with the unexposed group, the correlations between parental famine exposure during fetal period and their cognitive function (mother: β = -1.614, 95% CI: -2.535, -0.693; p = 0.001; father: β = -2.153, 95% CI: -3.104, -1.202, p < 0.001) were significant. For the offspring, there was a negative correlation between famine exposure of fathers during the fetal period and depression in their offspring (β = -0.477, 95% CI: -0.907, -0.047; p = 0.030). There was a negative correlation between maternal famine exposure during the infant and adolescent period and cognitive function in the offspring (math test: β = -0.730, 95% CI: -1.307, -0.153; p = 0.013; word test: β = -2.346, 95% CI: -4.067, -0.625; p = 0.008).

LIMITATIONS

Not all variables related to depression and cognition function were included in the CFPS database, and the other unknown or unmeasured confounders may explain our results.

Associations between depression, nutrition, and outcomes among individuals with coronary artery disease

OBJECTIVES

Depression and malnutrition are prevalent among people with coronary artery disease (CAD) and can affect their prognosis, but the relationship between depression and malnutrition and its co-effect on prognosis is not clear. We sought to explore that relationship and its effects.

METHODS

In this study, the nutritional and emotional statuses of 547 people with CAD were assessed using the Controlling Nutritional Status (CONUT) score and the Patient Health Questionnaire-9. The average follow-up period was 2.1 y, after which we explored the relationship between depression and nutrition and prognosis.

RESULTS

A total of 41% of the participants were found to have mild malnutrition, 10% moderate to severe malnutrition, 26% had mild depression, and 11% had moderate to severe depression. A total of 20.6% of the participants were found to have comorbidities of depression and malnutrition; and both moderate to severe depression (adjusted hazard ratio [HR], 1.674; 95% confidence interval [CI], 1.098-2.551) and moderate to severe malnutrition (adjusted HR, 1.686; 95% CI, 1.073-2.648) were observed to be risk factors for the composite end point. Participants with comorbidities of depression and malnutrition were found to have increased risk of cardiovascular death (HR, 5.390; 95% CI, 1.483-19.589) and composite end point (adjusted HR, 1.791; 95% CI, 1.133-2.833) compared to those without both depression and malnutrition.

CONCLUSIONS

Depression and malnutrition were found to be risk factors for adverse outcomes in people with CAD. People with CAD should pay attention to their emotional and nutritional statuses, and interventions must be timely and efficient.