Stress transgenerationally programs metabolic pathways linked to altered mental health

Abstract

Stress is among the primary causes of mental health disorders, which are the most common reason for disability worldwide. The ubiquity of these disorders, and the costs associated with them, lends a sense of urgency to the efforts to improve prediction and prevention. Down-stream metabolic changes are highly feasible and accessible indicators of pathophysiological processes underlying mental health disorders. Here, we show that remote and cumulative ancestral stress programs central metabolic pathways linked to mental health disorders. The studies used a rat model consisting of a multigenerational stress lineage (the great-great-grandmother and each subsequent generation experienced stress during pregnancy) and a transgenerational stress lineage (only the great-great-grandmother was stressed during pregnancy). Urine samples were collected from adult male F4 offspring and analyzed using ¹H NMR spectroscopy. The results of variable importance analysis based on random variable combination were used for unsupervised multivariate principal component analysis and hierarchical clustering analysis, as well as metabolite set enrichment analysis (MSEA) and pathway analysis. We identified distinct metabolic profiles associated with the multigenerational and transgenerational stress phenotype, with consistent upregulation of hippurate and downregulation of tyrosine, threonine, and histamine. MSEA and pathway analysis showed that these metabolites are involved in catecholamine biosynthesis, immune responses, and microbial host interactions. The identification of metabolic signatures linked to ancestral programming assists in the discovery of gene targets for future studies of epigenetic regulation in pathogenic processes. Ultimately, this research can lead to biomarker discovery for better prediction and prevention of mental health disorders.

Keywords: 1H nuclear magnetic resonance spectroscopy; Disease etiology; Metabolic profile; Metabolite set enrichment analysis; Multigenerational stress; Pathway analysis; Transgenerational stress.

Fig. 1

Illustration of the experimental design that tested the F4 offspring of a lineage in which stress occurred in each generation (multigenerational stress, SSSS) or in which stress was limited to the first parental generation (transgenerational stress, SNNN). A lineage of non-stressed rats (NNNN) served as control

Fig. 2

Scores plots showing components 1 (X-axis) and 2 (Y-axis) of the PCA analysis for a, c F4-SSSS multigenerationally stressed lineage versus controls and b, d F4-SNNN transgenerationally stressed lineage versus controls. a, b The result of the analysis when all metabolites were considered, while c, d the result of the analysis when only the metabolites identified by VIAVC were considered. The percentages shown along each axis indicate the amount of the variance in the data set given by each component, and the shaded ellipses designate the 95 % confidence interval for each group

Fig. 3

Heat maps for a F4-SSSS multigenerationally stressed lineage versus controls and b F4-SNNN transgenerationally stressed lineage versus controls. The X- and Y-axis show the class and the metabolite identity, respectively. These heat maps visually indicate either upregulation or downregulation of the metabolites presented in Table 1. The legend corresponding to the class label and the heat map for both figures is shown to the right of figure b. 1-MN 1-methylnicotinamide, IMP inosine monophospate. The labels 1-MN, 1-MN.1, and 1-MN.2, as well as histamine and histamine.1 correspond to different resonance peaks of the same metabolite. The dendrogram at the top of each heat map illustrates the results of the unsupervised hierarchical clustering analysis

Fig. 4

Scores plot illustrating components 1 (X-axis) and 2 (Y-axis) of the PCA analysis for the F4-SSSS multigenerationally stressed lineage versus the F4-SNNN transgenerationally stressed lineage when considering the metabolites identified by the VIAVC analysis. The percentages shown along each axis indicate the amount of the variance in the data set given by each component and the shaded ellipses designate the 95 % confidence interval for each group

Fig. 5

Summary plot for the over representation analysis of metabolic pathways associated with the complete list of metabolites shown in Table 1. The p values for the metabolic pathways are color coded with dark red being highly significant and white being least significant. The category “intracellular signaling” stands for intracellular signaling through the H2 receptor and histamine

Fig. 6

Pearson correlations to assess the relationship between anxiety-like behavior (i.e., average center distance traveled) and the relative concentrations of histamine (a) and tyrosine (b). There were positive correlations between the distance score and histamine (r = 0.55, p = 0.0045), and tyrosine (r = 0.21, p = 0.177), indicating that a higher anxiety-like state was linked to lower histamine and tyrosine concentrations