Expression of transcription factors and precursor cell markers during regeneration of β cells in pancreata of rats treated with streptozotocin

An understanding of β cell regeneration is needed if we are to develop new treatment modalities in diabetes mellitus. Lineage tracing studies have shown that all pancreatic cell types, including β cells, arise from PDX-1-expressing precursor cells. We studied β cell regeneration by analyzing the immunocytochemical expression of the transcription factors, PDX-1, PBX-1, and MEIS2, and that of the potential precursor cell markers, c-Kit and nestin, using the model of streptozotocin (STZ)-induced diabetes in rats. The pancreata were examined 3, 7, and 14 days after STZ administration. PDX-1 expression, but not that of MEIS2 and PBX-1, transiently increased on day 7. c-Kit expression was found to be upregulated in islet cells at all points in time, while nestin expression was lacking. Ki-67 labeling was increased in islets on days 3 and 7. These results suggest that temporary upregulation of PDX-1 and prolonged overexpression of c-Kit may play a role during β cell regeneration.