Jason Ray, Benjamin Bitner, Kyle Kener, and Brent Jackson, Brigham Young University
Life Sciences
Type 1 and Type 2 diabetes are increasing at an alarming rate. Both types of diabetes result in decreased functional β-cell mass, which is defined as the number of β-cells multiplied by their Glucose Stimulated Insulin Secretion rate. Decreased functional β-cell mass inhibits regulation of blood glucose levels. β-cells have an extremely low proliferation rate after adolescence, meaning the functional β-cell mass cannot naturally recover. Increasing functional β-cell mass could provide a cure for diabetes, either through pancreatic islet transplants or through enhancement of the endogenous β-cell population. Nkx6.1 has been shown to increase β-cell proliferation by inducing the nuclear receptors Nr4a.1 and Nr4a.3. We have shown that Nkx6.1 increases expression of the gene c-Fos, and that c-Fos induces expression of Nr4a1 and Nr4a3. Furthermore, we have shown that c-Fos is sufficient to induce proliferation of β-cells in the INS-1 832/3 cell line and in primary rat islets. Finally, using lenti-sh-c-Fos to create a stable c-Fos deficient stable cell line, we have demonstrated that Nkx6.1 mediated proliferation is modified by the lack of c-Fos. We propose a model by which c-Fos is a critical link between Nkx6.1 and Nr4a mediated β-cell proliferation.