In their studies, the scientists at Beckman Research Institute of City of Hope demonstrated that Ten eleven translocation (TET) enzymes and thymine DNA glycosylase (TDG) can be direct targets of the microRNA miR-26a. These DNA demethylation enzymes are down-regulated in islets during postnatal differentiation, whereas miR-26a is up-regulated. They also report that changes in 5-hydroxymethylcytosine accompany changes in TET mRNA levels and over expression of miR-26a in mice increases postnatal islet cell number in vivo and endocrine/acinar colonies in vitro.
Furthermore, TET1/2/3 and TDG play crucial roles in early embryonic and germ cell development by mediating DNA demethylation. However, the molecular mechanisms that regulate TETs/TDG expression and their role in cellular differentiation, including that of the pancreas, are not known. These findings establish a previously unknown link between miRNAs and TET expression levels, and suggest a potential role for miR-26a and TET family proteins in pancreatic cell differentiation.
Source: Learn all about it and read more about their findings here: Fu X et al: MicroRNA-26a targets ten eleven translocation enzymes and is regulated during pancreatic cell differentiation. Proc Natl Acad Sci U S A. 2013 Oct 10. [Epub ahead of print]