Endocrine Abstracts

Background: Low dietary protein content has been linked to causing altered lipid metabolism, as well as affecting developmental trajectory of offspring if fed during the periconceptional period, increasing their risk of developing non-communicable diseases in adulthood. Until now, effects of poor maternal or paternal diet have been investigated individually and not in combination. However, a parental combinatorial assessment would have more clinical relevance as both parents would likely be consuming the same diet prior to conception.

Methods: Male and female 8-week-old C57BL/6 mice were fed either a control normal protein diet (NPD; 18% casein) or an isocaloric LPD (LPD; 9% casein) for a minimum of 8 weeks. Mice were mated in a 2x2 factorial design, resulting in four dietary groups: NN (NPD female, NPD male), NL (NPD female, LPD male), LN (LPD female, NPD male) and LL (LPD female, LPD male). Females were culled on embryonic (E) day 1.5 (E1.5) for the collection and culture of preimplantation embryos in a time-lapse system (Embryoscope). RNA was isolated from parental liver and gonadal adipose. Following reverse transcription to synthesize cDNA, qPCR was carried out to determine the difference in relative gene expression between diets.

Results: Though not statistically significant, a 25% reduction in the numbers of embryos reaching the blastocyst stage was observed in the LL diet group when compared to the NN, NL and LN groups. In paternal tissue, liver Cpt1a, adipose Acacb1 and Fasn expression were significantly upregulated following LPD. In maternal tissue, liver Igf1 expression was significantly downregulated, whereas adipose Fasn was significantly upregulated.

Conclusions: Our data indicates that when both parents consume the same sub-optimal LPD, the impact on embryo development is greater than for either parent alone. Sex-specific changes to expression of genes involved in lipid metabolism were observed in both liver and adipose tissues of parents.