In an effort to determine what causes immune mediated diseases such as ankylosing spondylitis, inflammatory bowel disease and psoriasis, researchers have focused on learning more about genetic pathogenic pathways responsible for autoimmunity. In this article, we review the data and highlight best practices.
In an effort to determine what causes immune mediated diseases such as ankylosing spondylitis, inflammatory bowel disease and psoriasis, researchers have focused on learning more about genetic pathogenic pathways responsible for autoimmunity.
Published in Arthritis Research & Therapy, Jessica Whyte and colleagues in Australia present this review of proper experimental design and consistency of approach in future research in an effort to understand the functional role of DNA methylation in immune-mediated disease.
Ankylosing spondylitis, inflammatory bowel disease and psoriasis belong to a group of seronegative autoimmune diseases that are closely related, often co-occur, and share genes that confer susceptibility.
Even though great strides have been made in mapping the genomic basis of autoimmunity, the authors point out that less than 28 percent of the heritability of these diseases has been determined.
DNA methylation is an epigenetic or functional modification that occurs throughout life and represents the most robust and tractable epigenetic measurement method we have. Essentially methylation refers to the addition of a methyl group (CH3) to a cytosine on DNA to form 5-methylcytosine (5mC).
DNA methylation is a very stable marker that is maintained through mitosis and is moderately heritable between generations. The loss of methylation on cytosine results in a stable alternative nucleotide thymine. Cytosine to thymine mutations are the most common observed in mammals.
Methylation, or epigenetics, can lead to gene silencing in some cases and gene activation in others. The methylation of DNA may be useful in studying disease as a biomarker for disease outcome/severity, or to uncover transcriptional control and determine the effect of genetic changes on function.
“Despite evidence in twin studies that epigenetics is a major mechanism through which immune-mediated disease- associated variants affect function, the role of DNA methylation, the most well-characterized epigenetic mechanism, in immune-mediated diseases remains largely unknown,” the authors wrote.
Jessica M. Whyte, Jonathan J. Ellis, Matthew A. Brown, et al. "Best practices in DNA methylation: lessons from inflammatory bowel disease, psoriasis and ankylosing spondylitis." Arthritis Research & Therapy. https://doi.org/10.1186/s13075-019-1922-y