Altered methylations of H19, Snrpn, Mest and Peg3 are reversible by developmental reprogramming in kidney tissue of ICSI-derived mice

Abstract

Although the prevalence of Intracytoplasmic sperm injection (ICSI) has increased year by year, there remains concern about the safety of these procedures because of reports of the increased risk for imprinting disorders. Previous research has demonstrated that gonadotropin stimulation contributes to an increased incidence of epimutations in ICSI-derived mice. However, the epimutations in ICSI offspring after removing the effect of gonadotropin stimulation and the possibility that epimutations are reversible by developmental reprogramming has not been investigated. Our study is the first to investigate the effect of ICSI itself on methylation and exclude the effect of superovulation using the kidney tissues from the adult and old mice. We found reduced methylation and up-regulated expression of the imprinted genes, H19, Mest and Peg3, in adult ICSI mice, but the above alterations observed in adult mice were not detected in old ICSI mice. At the Snrpn DMR, methylation status was not altered in adult ICSI-derived mice, but hypermethylation and correlated down-regulated expression of Snrpn were observed in old mice. In conclusion, ICSI manipulation and early embryo culture resulted in alterations of methylation in differentially methylated region of H19, Mest, Peg3 and Snrpn, and the alterations were reprogrammed by developmental reprogramming.

Epigenetic mechanisms involved in intrauterine growth restriction and aberrant kidney development and function

“…As Dnmt3a changes were found in F1 IUGR offspring at E20, a critical time point in rat's nephron formation, imprinted genes involved in kidney development (Peg3, Snrpn, Kcnq1, and Cdkn1c) were also investigated. [35][36][37][38][39][40] In regard to Kcnq1, there was an increase in expression in F1 IUGR rats at PN1 (1.6-fold change, P < 0.01) compared to sham, despite a similar expression at E20 (Fig. 6).…”

Regulation of glutamate transport and neuroinflammation in a term newborn rat model of hypoxic–ischaemic brain injury

“…As an imprinted gene, Peg3 should show approximately 50% methylation in all cells, providing an internal control for successful bisulphite conversion and pyrosequencing. Given the lack of Peg3 studies in rat in the wider literature, primers were designed to target a small region homologous to the mouse imprinted differentially methylated region (DMR) ( Zhan et al, 2017 ). Pyrosequencing technology can robustly sequence small regions of the genome (up to 60–80 bp), and the number of CpG sites varies by region depending on CpG density ( Glt1 CpG island: seven CpGs; Glt1 proximal promoter: three CpGs; Glt1 distal shore: two CpGs and Peg3 : five CpGs).…”