A protein known to drive programmed death of pancreatic beta cells in both type 1 and type 2 diabetes also causes these cells to stop making insulin, report researchers from the University of Alabama at Birmingham (Xu G et al. Nat Med. doi:10.1038/nm.3287 [published online August 25, 2013]).
Experiments using microarrays as well as cells from mice and humans revealed that the protein, called thioredoxin-interacting protein (TXNIP), triggers beta cells to make a short piece of genetic material called microRNA-204 that interferes with expression of MAFA, a transcription factor known to turn on the insulin gene. The researchers also found that TXNIP induces microRNA-204 by inhibiting the activity of another transcription factor, called signal transducer and activator of transcription 3 (STAT3).
Hampton T. Protein May Play Dual Role in Diabetes Pathogenesis. JAMA. 2013;310(13):1331. doi:10.1001/jama.2013.279212