DNA was isolated with AllPrep DNA/RNA/miRNA universal kit (Qiagen, Germantown, MD, USA) according to the manufacturer’s instructions. Genomic DNA was bisulfite-converted using EZ DNA Methylation-Lightning™ Kit (Zymo Research Corp, CA, USA) according to the manufacturer’s instructions. Bisulfite primers were designed to span the promoter region of Ppard, Ccnd1, and Nr4a3 genes within -3000 to +2000 base pairs relative to transcriptional start site (TSS) (Table 1, Figure 3) using MethPrimer program (Li and Dahiya, 2002)