Adverse maternal environment and western diet impairs cognitive function and alters hippocampal glucocorticoid receptor promoter methylation in male mice.

Abstract

Adverse maternal environment (AME) and high-fat diet in early childhood increase the risk of cognitive impairment and depression later in life. Cognitive impairment associates with hippocampal dysfunction. A key regulator of hippocampal function is the glucocorticoid receptor. Increased hippocampal GR expression associates with cognitive impairment and depression. Transcriptional control of GR relies in part upon the DNA methylation status at multiple alternative initiation sites that are tissue specific, with exon 1.7 being hippocampal specific. Increased exon 1.7 expression associates with upregulated hippocampal GR expression in early life stress animal models. However, the effects of AME combined with postweaning western diet (WD) on offspring behaviors and the expression of GR exon 1 variants in the hippocampus are unknown. We hypothesized that AME and postweaning WD would impair cognitive function and cause depression-like behavior in offspring in conjunction with dysregulated hippocampal expression of total GR and exon 1.7 variant in mice. We found that AME-WD impaired learning and memory in male adult offspring concurrently with increased hippocampal expression of total GR and GR 1.7. We also found that increased GR 1.7 expression was associated with decreased DNA methylation at the GR 1.7 promoter. We speculate that decreased DNA methylation at the GR 1.7 promoter plays a role in AME-WD induced increase of GR in the hippocampus. This increased GR expression may subsequently contribute to hippocampus dysfunction and lead to the cognitive impairment seen in this model.

• Authors: Xingrao Ke, Qi Fu, Jennifer Sterrett, Cecilia J Hillard, Robert H Lane, Amber Majnik
• Journal: Physiological reports (Physiol Rep) Vol. 8 Issue 8 Pg. e14407 (04 2020) ISSN: 2051-817X [Electronic] United States
• PMID: 32333646 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2020 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Chemical References

• Receptors, Glucocorticoid

Topics

• Animals
• Cognitive Dysfunction (genetics, metabolism, pathology)
• DNA Methylation
• Diet, Western (adverse effects)
• Female
• Fetal Development
• Hippocampus (drug effects, metabolism, pathology)
• Male
• Maternal Exposure (adverse effects)
• Maternal-Fetal Exchange
• Mice
• Mice, Inbred C57BL
• Pregnancy
• Prenatal Exposure Delayed Effects
• Promoter Regions, Genetic
• Random Allocation
• Receptors, Glucocorticoid (biosynthesis, genetics, metabolism)