Peri-conceptional under-nutrition alters the expression of TRIM28 and ZFP57 in the endometrium and embryos during peri-implantation period in domestic pigs
DNA methylation is maintained by the main elements of methylation complex—tripartite motif containing 28 (TRIM28) and zinc finger protein 57 (ZFP57). Previously, it was found that the activity of TRIM28 and ZFP57 determines the process of DNA methylation and preserves over-expression of genes. We hypothesized that restricted diet applied during peri-conceptional period may induce changes in the expression of methylation complex in porcine endometrium and embryos during the peri-implantation period. The aim of this study was to detect and determine the expression of TRIM28 and ZFP57 in the endometrium and embryos harvested from gilts during the peri-implantation period (days 15–16 of pregnancy) fed restricted (n = 5) or normal (n = 5) diet during peri-conceptional period. In restricted-diet-fed gilts, endometrial expression of TRIM28 and ZFP57 mRNAs was decreased in comparison with normal-diet-fed gilts (p ≤ .01), while the embryonic expression of TRIM28 and ZFP57 mRNAs was increased in restricted-diet-fed gilts (p ≤ .05). The immunofluorescence showed the presence of TRIM28 and ZFP57 in luminal epithelial (LE), glandular epithelial (GE) and stromal cells (ST) of the endometrium as well as in the embryos. Total endometrial and embryonic abundance of TRIM28 and ZFP57 proteins was significantly higher (p ≤ .05) in restricted-diet-fed gilts than in normal-diet-fed gilts. Female under-nutrition during peri-conceptional period affects the expression of two main elements of methylation complex in the endometrium and in embryos during the peri-implantation period and may have the impact on DNA methylation in these tissues.