Obesity reprograms muscle stem cells
n a new study, doctoral student Cajsa Davegårdh has studied so-called DNA methylation in muscle stem cells in both obese and non-obese individuals. DNA methylation is an epigenetic process in which small molecules -- methyl groups -are added to genes and fine-tune the gene's activity, like a dimmer switch. By comparing the DNA methylation in immature and mature muscle cells from healthy individuals, Cajsa Davegårdh discovered that the actual degree of methylation had a major impact on the maturation process. "Many genes that had changed their genetic expression also changed their degree of methylation during the development to mature muscle cells, which indicates a connection," she says. A pro-inflammatory gene, IL-32, turned out to be particularly important with regard to the maturation process and the insulin sensitivity of the fully developed muscle cell. Impaired insulin sensitivity is common in obesity and is a risk factor for type 2 diabetes. "By re...