Abstract: SA-PO557

DNA Hydroxymethylation Is Altered by Maternal Nutrient Restriction in Rat Kidney

Session Information

  • Developmental Biology
    November 04, 2017 | Location: Hall H, Morial Convention Center
    Abstract Time: 10:00 AM - 10:00 AM

Category: Developmental Biology and Inherited Kidney Diseases

  • 401 Developmental Biology

Authors

  • Hida, Mariko, Keio University School of Medicine, Tokyo, Japan
  • Oda, Mayumi, Keio University School of Medicine, Tokyo, Japan
  • Awazu, Midori, Keio University School of Medicine, Tokyo, Japan
Background

DNA hydroxymethylation is an epigenetic modification that oxidizes 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC). Increasing evidence suggests that the role of DNA hydroxymethylation is different from DNA methylation in various organs but that in the kidney is unclear. We previously showed that the global DNA methylation was reduced and the gene-specific DNA methylation was altered in kidney of rat embryos from nutrient-restricted mothers. In the present study, we investigated DNA hydroxymethylation in the same model.

Methods

The kidneys of embryonic day 18 fetuses (E18) from dams given food ad libitum (CON) and those subjected to 50% food restriction throughout pregnancy (NR) were examined (n=3 litters for each group). Global hydroxymethylation levels were assessed by ELISA. The local 5hmC detection by hMe-Seal method followed by high throughput sequencing (5hmC-seq) was used to analyze the changes in hydroxymethylation patterns by NR. 5hmC enriched regions (5hmC peaks) were identified using a peak finding algorithm (MACS1.4) and then annotated to the nearest genes.

Results

Global hydroxymethylation levels in E18 metanephroi was significantly increased in NR vs CON (0.31±0.02% vs 0.20±0.03%). On the other hand, the number of 5hmC peaks detected by 5hmC-seq analysis was smaller in NR; 582 peaks in CON only and169 peaks in NR only. There were 362 peaks common in CON and NR. Annotated genes present in these regions were 581 and 169 in CON and NR, respectively. Most of the identified 5hmC sites reside in intergenic regions, followed by introns, while the sites near the transcriptional start sites were few. Among genes with CON-specific hydroxymethylated peaks, some genes were related to the kidney development (Amph1, Glcci, Gli3, Igfbp3, Cdh11, FGF10, Ihh, and Agtr1a, in descending order of peak score). Genes with NR-specific hydroxymethylated peaks also had a few kidney development genes (Edn2, Igfbp3, and Fst). Protein expression of Amph1 and Cdh11 was upregulated in NR. The transcript level of Agtr1a assessed by PCR was not different between CON and NR.

Conclusion

Maternal nutrient restriction increased the global DNA hydroxymethylation and changed the local hydroxymethylation in genes involved in kidney development.

Funding

  • Government Support - Non-U.S.