Background and previous work
The reproductive lifespan of women is restricted. Offspring of older women have an
increased risk for various disorders, for example for type-1 diabetes. The preimplantation period is a critical ontogenetic stage in embryo development and highly vulnerable for teratogenesis and epigenetic modifications. In this period, the embryo is most sensitive to its surrounding milieu, especially to deregulations by external stimuli. In our previous studies we demonstrated that a maternal hyperglycaemia (diabetes type 1) during early pregnancy is correlated with an increase in AGE formation in the uterine environment and the embryo itself. AGE accumulation and the activation of the receptor for AGEs (RAGE) influenced the development of the embryo by increasing AGE-mediated cellular stress. The embryo adapts metabolically by gene expression changes to ensure survival. According to the concept of “Developmental origins of health and diseases” (DOHAD), changes in embryonic cell physiology affect later development and predispose for metabolic diseases and ageing.
Our working hypothesis is that maternal age and metabolic stress modulate key metabolic factors as early as during embryo development. Protein modifications are likely targets leading to metabolic (epigenetic) programming in offspring with lifelong consequences for ageing and health.
Due to the high yield of material for analysis from individual blastocysts, rabbit embryos will be used in the project. Non-enzymatic age-dependent protein modifications in blastocysts and cavity fluids of blastocysts from young (20 weeks) and old (130 weeks) females, diabetic and healthy donors will be analysed by two-dimensional (2D) gel electrophoresis followed by immunoblotting for AGEs. Modified proteins will be identified by mass spectroscopy and assessed by bioinformatics for functional networks (collaboration with SP5). We will continue collaborating with SP1, SP8 and SP2 on analyses of altered glycation and sialylation of embryonic tissues and fluids. Depending on the proteins identified, their role in cell signalling, gene transcription/translation and regulation will be analysed in collaboration with SP4, SP9, SP10, SP13 and SP14. Human and mouse embryonic stem cell lines will be used as in vitro models to investigate specific protein functions. As target molecule of metabolic and stress-related signalling pathways, the regulation and modification of FOXO transcription factor 1 will be studied in blastocysts from young and old, diabetic and healthy donors (collaborations with SP4, SP9, SP13, and SP14).