The UCLA researchers show that chemical tags called “methyl groups” that bind to DNA — where they act like a volume knob, turning up or down the activity of certain genes — are crucial to understanding how cells can be converted into insulin-secreting beta cells. They show that DNA methylation keeps ARX, a gene that triggers the formation of glucagon-secreting alpha cells in the embryonic pancreas, silent in beta cells.
Deletion of Dnmt1, the enzyme responsible for DNA methylation, from insulin-producing beta cells converts them into alpha cells.
These findings suggest that a defect in beta cells’ DNA methylation process interferes with their ability to maintain their “identity.” So if this “epigenetic mechanism,” as the researchers call it, can produce alpha cells, there may be an analogous mechanism that can produce beta cells that would maintain blood sugar equilibrium.
Source: http://www.uclahealth.org