title: A novel biomarker for acute kidney injury using TaqMan-based unmethylated DNA-specific polymerase chain reaction.
abstract: There has been increasing interest in the use of circulating DNA as biomarkers for various tissue injuries, cancers, and fetal conditions. DNA methylation is a well-characterized mechanism underlying the epigenetic regulation of gene expression, and many diagnostic tests based on DNA methylation patterns have been developed. We developed a novel TaqMan-based assay for the detection of acute kidney injury using a hypomethylated promoter region of Slc22a12, a urate transporter specifically expressed in proximal tubular cells. Bisulfite sequencing analysis confirmed that the CpG islands in the promoter region of mouse Slc22a12 were preferentially hypomethylated in the kidney cortex. TaqMan minor groove binder (MGB) probes reliably discriminated the DNA fragments corresponding to the unmethylated and methylated promoter regions of Slc22a12. Plasma levels of unmethylated DNA corresponding to the Slc22a12 promoter region were undetectable at baseline and were significantly elevated after acute kidney cortex necrosis. This study showed the usefulness of the TaqMan system in discriminating methylated and unmethylated DNA fragments, and the similar strategy can be applied for establishing biomarkers for various cellular injuries or pathological conditions.
authors.affiliation: Department of Genomic Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Endo
authors.forename: Naoko
authors.initials: N
authors.lastname: Kito
authors.forename: Yasue
authors.initials: Y
authors.lastname: Fukushima
authors.forename: Huachun
authors.initials: H
authors.lastname: Weng
authors.forename: Naoharu
authors.initials: N
authors.lastname: Iwai
mesh_terms: D058186:Acute Kidney Injury / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D015415:Biomarkers; D018899:CpG Islands; D019175:DNA Methylation; D004195:Disease Models, Animal; D044127:Epigenesis, Genetic; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D027361:Organic Anion Transporters / Q000235:genetics; D011401:Promoter Regions, Genetic; D060888:Real-Time Polymerase Chain Reaction; D015203:Reproducibility of Results
chemical_list: D015415:Biomarkers; D027361:Organic Anion Transporters; C109687:Slc22a12 protein, mouse