Imprinted gene alterations in the kidneys of growth restricted offspring may be mediated by a long non-coding RNA.

Altered epigenetic mechanisms have been previously reported in growth restricted offspring whose mothers experienced environmental insults during pregnancy in both human and rodent studies. We previously reported changes in the expression of the DNA methyltransferase and the imprinted genes (Cyclin-dependent kinase inhibitor 1C) and (Potassium voltage-gated channel subfamily Q member 1) in the kidney tissue of growth restricted rats whose mothers had uteroplacental insufficiency induced on day 18 of gestation, at both embryonic day 20 (E20) and postnatal day 1 (PN1). To determine the mechanisms responsible for changes in the expression of these imprinted genes, we investigated DNA methylation of KvDMR1, an imprinting control region (ICR) that includes the promoter of the antisense long non-coding RNA ( opposite strand/antisense transcript 1). expression decreased by 51% in growth restricted offspring compared to sham at PN1. Interestingly, there was a negative correlation between and in the E20 growth restricted group (Spearman's  0.014). No correlation was observed between and expression in either group at any time point. Additionally, there was a 11.25% decrease in the methylation level at one CpG site within KvDMR1 ICR. This study, together with others in the literature, supports that long non-coding RNAs may mediate changes seen in tissues of growth restricted offspring.