Another paper has been accepted from our group. Genes and Nutrition have confirmed that they will be publishing ‘Exposure of neonatal rats to maternal cafeteria feeding during suckling alters hepatic gene expression and DNA methylation in the insulin signalling pathway‘. Authors on this one are Zoe Daniel, Asli Akyol, Sarah McMullen and myself. The paper will be out in January.
The work is an important outcome from a major experiment that we ran three years ago as part of Asli’s PhD studies. It examined the contribution of maternal obesity prior to and during pregnancy and during lactation upon adiposity and metabolic indices in the affected offspring. Her work showed some impairment of glucose tolerance associated with cafeteria feeding during lactation and this new paper provides some clues to the mechanism.
The abstract is below:
Nutrition in early life is a determinant of lifelong physiological and metabolic function. Diseases that are associated with ageing may, therefore, have their antecedents in maternal nutrition during pregnancy and lactation. Rat mothers were fed either a standard laboratory chow diet (C) or a cafeteria diet (O) based upon a varied panel of highly palatable human foods, during lactation. Their offspring were then weaned onto chow or cafeteria diet giving four groups of animals (CC, CO, OC, OO n=9-10). Livers were harvested 10 weeks post-weaning for assessment of gene and protein expression, and DNA methylation. Cafeteria feeding post-weaning impaired glucose tolerance and was associated with sex-specific altered mRNA expression of peroxisome proliferator activated receptor gamma (PPARg) and components of the insulin-signalling pathway (Irs2, Akt1 and IrB). Exposure to the cafeteria diet during the suckling period modified the later response to the dietary challenge. Post-weaning cafeteria feeding only down-regulated IrB when associated with cafeteria feeding during suckling (group OO, interaction of diet in weaning and lactation P=0.041). Responses to cafeteria diet during both phases of the experiment varied between males and females. Global DNA methylation was altered in the liver following cafeteria feeding in the post-weaning period, in males but not females. Methylation of the IrB promoter was increased in group OC, but not OO (P=0.036). The findings of this study add to a growing evidence base that suggests tissue function across the lifespan a product of cumulative modifications to the epigenome and transcriptome, which may be both tissue and sex-specific.
The wider body of work also spawned studies with Peter Voigt in the Nottingham Vet School, which led to Thom Wright’s PhD on behavioural changes associated with maternal cafeteria feeding.