Figure 1.
The effect of TCE on mouse liver transcriptome by microarray (n = 3).
A) Heat map of mouse liver mRNAs affected by TCE at a dose level of 1000 mg/kg b.w. B) Go biological process annotations. C) Enriched pathways of the expression changed genes by KEGG.
Figure 2.
Selected gene expression changes in the liver of mice exposed to different doses of TCE (0, 100, 500 and 1000 mg/kg b.w.) (n = 3).
A) qPCR analysis of selected mRNA expression changes in mouse liver. B) Western analysis of Dnmt1 protein expression levels. Fold expression at each dose was calculated against the nonexposed samples (TCE dose level at 0 mg/kg). *, p<0.05; **, p<0.01. ***, p<0.001.
Table 1.
Comparison of mRNA expression changes detected by microarray and qPCR in mouse liver exposed to TCE at a dose level of 1000 mg/kg b.w. (n = 3).
Figure 3.
DNA methylation status of the promoter regions of Cdkn1a and Ihh in the liver of mice exposed to different doses of TCE (0, 100, 500 and 1000 mg/kg b.w.) (n = 3).
A, D) Nucleotide sequences of Cdkn1a and Ihh promoter region fragments (upper strands) and the corresponding bisulphite-converted sequences (lower strands). CpG dinucleotides are numbered and marked in bold. The restriction enzyme cut sites are marked in italic. Primer sequences are underlined. B, E) Bisulfite sequencing of the Cdkn1a and Ihh promoter regions. Open and closed circles indicate unmethylated and methylated CpG sites respectively. Percent methylation is shown in parentheses. C) COBRA result of the promoter region of Cdkn1a at CpG4-5(CGCG) by BstUI 184 bp (84/100); L: Tiangen DNA ladder II; P, positive control by treating mouse genomic DNA with M.SssI. C, liver samples from mice exposed to corn oil; T, liver samples from mice exposed to TCE at 1000 mg/kg b.w. M, methylation; UM, unmethylation.
Figure 4.
DNA methylation status of the promoter regions of Jun and Myc in the liver from mice exposed to TCE at 0 or 1000 mg/kg b.w. (n = 3).
A, D) Nucleotide sequences of Jun and Myc promoter region fragments (upper strands) and the corresponding bisulphite-converted sequences (lower strands). CpG dinucleotides are numbered and marked in bold. The restriction enzyme cut sites are marked in italic. Primer sequences are underlined. (B, E) Bisulfite sequencing of the Jun and Myc promoter regions. Open and closed circles indicate unmethylated and methylated CpG sites respectively. C) COBRA result of the promoter region of Jun at CpG3,4 (CGCG) by BstUI 171 bp (49/122). F) COBRA result of the promoter region of Myc at CpG4 (TCGA) by TaqI 132 bp (88/43). L: Tiangen DNA ladder; P, positive control by treating mouse genomic DNA with M.SssI. C, control liver samples; T, liver samples treated with TCE at 1000 mg/kg b.w. M methylation; UM, unmethylation.
Table 2.
mRNA expression changes in BNL CL.2 mouse liver cells after 5aza treatment (n = 3).
Figure 5.
Global DNA methylation status of the liver of mice exposed to TCE.
A–C) Bisulfite sequencing of the LINE-1, LAP-LTR and SINE B1 repetitive elements in the liver of mice treated with TCE at 0 or 1000 mg/kg b.w. Open and closed circles indicate unmethylated and methylated CpG sites respectively. Some sites are absent from the sequences in some clones due to mutations in the particular copies of the repetitive sequences. Percent methylation is shown in parentheses. D) The content of 5-mC detected by LC-MS/MS. (n = 5).