Journal Article

Altered DNA Methylation in Leukocytes with Trisomy 21

Croy, B. Anne, Silverman, Wayne, Hatta, Kota, Schork, Nicholas J., Mayeux, Richard P., Torkamani, Ali, Murty, Vundavalli, Kerkel, Kristi, Kratz, Alexander, Schupf, Nicole, Salas, Martha, Jenkins, Edmund C., Tycko, Benjamin, Minden, Mark, Pang, Deborah, Zigman, Warren B.

2010

Overview

The primary abnormality in Down syndrome (DS), trisomy 21, is well known; but how this chromosomal gain produces the complex DS phenotype, including immune system defects, is not well understood. We profiled DNA methylation in total peripheral blood leukocytes (PBL) and T-lymphocytes from adults with DS and normal controls and found gene-specific abnormalities of CpG methylation in DS, with many of the differentially methylated genes having known or predicted roles in lymphocyte development and function. Validation of the microarray data by bisulfite sequencing and methylation-sensitive Pyrosequencing (MS-Pyroseq) confirmed strong differences in methylation (p<0.0001) for each of 8 genes tested: TMEM131, TCF7, CD3Z/CD247, SH3BP2, EIF4E, PLD6, SUMO3, and CPT1B, in DS versus control PBL. In addition, we validated differential methylation of NOD2/CARD15 by bisulfite sequencing in DS versus control T-cells. The differentially methylated genes were found on various autosomes, with no enrichment on chromosome 21. Differences in methylation were generally stable in a given individual, remained significant after adjusting for age, and were not due to altered cell counts. Some but not all of the differentially methylated genes showed different mean mRNA expression in DS versus control PBL; and the altered expression of 5 of these genes, TMEM131, TCF7, CD3Z, NOD2, and NPDC1, was recapitulated by exposing normal lymphocytes to the demethylating drug 5-aza-2'deoxycytidine (5aza-dC) plus mitogens. We conclude that altered gene-specific DNA methylation is a recurrent and functionally relevant downstream response to trisomy 21 in human cells.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adult / Aging - genetics / Analysis / Azacitidine - pharmacology / Child / Child, Preschool / Deoxyribonucleic acid / DNA / DNA methylation / DNA Methylation - drug effects / DNA Methylation - genetics / Down syndrome / Down Syndrome - genetics / Gene Expression Profiling / Gene Expression Regulation - drug effects / Genes / Genetic aspects / Genetics / Genetics and Genomics / Genetics and Genomics/Chromosome Biology / Genetics and Genomics/Epigenetics / Genetics and Genomics/Genetics of Disease / Genetics and Genomics/Medical Genetics / Humans / Immune system / Infant / Jurkat Cells / Leukocyte Count / Leukocytes / Leukocytes - drug effects / Leukocytes - metabolism / Lymphocytes - drug effects / Lymphocytes - metabolism / Methylation / Nerve Tissue Proteins - genetics / Nerve Tissue Proteins - metabolism / Nod2 Signaling Adaptor Protein - genetics / Nod2 Signaling Adaptor Protein - metabolism / Oligonucleotide Array Sequence Analysis / Physiological aspects / Reproducibility of Results / RNA, Messenger - genetics / RNA, Messenger - metabolism / Sequence Analysis, DNA / Sulfites / Trisomy