SerpinB1 Promotes Pancreatic β Cell Proliferation
- Cell Metab. 2016 Jan 12;23(1):194-205. doi: 10.1016/j.cmet.2015.12.001.
- 1. Islet Cell and Regenerative Medicine, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Harvard Stem Cell Institute, Boston, MA 02215, USA.
- 2. Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352, USA.
- 3. Program in Cellular and Molecular Medicine at Boston Children's Hospital, 3 Blackfan Circle, Boston, MA 02215, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02215, USA.
- 4. Program in Cellular and Molecular Medicine at Boston Children's Hospital, 3 Blackfan Circle, Boston, MA 02215, USA.
- 5. Department of Cell and Molecular Biology, Karolinska Institutet, von Eulers väg 3, 17177 Stockholm, Sweden.
- 6. Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL 60612, USA.
- 7. Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA; Cardiovascular and Metabolic Diseases iMed, AstraZeneca R&D, 431 83 Mölndal, Sweden.
- 8. University Hospital Zurich, Department of Dermatology, 8006 Zurich, Switzerland.
- 9. Section on Genetics and Epidemiology, Joslin Diabetes Center and Harvard Medical School, Boston, MA 02215, USA.
- 10. Section on Clinical Research, Joslin Diabetes Center and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA.
- 11. Program in Cellular and Molecular Medicine at Boston Children's Hospital, 3 Blackfan Circle, Boston, MA 02215, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02215, USA; Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA 02215, USA.
- 12. Islet Cell and Regenerative Medicine, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Harvard Stem Cell Institute, Boston, MA 02215, USA. Electronic address: [email protected].
Although compensatory islet hyperplasia in response to Insulin resistance is a recognized feature in diabetes, the factor(s) that promote β cell proliferation have been elusive. We previously reported that the liver is a source for such factors in the liver Insulin Receptor knockout (LIRKO) mouse, an Insulin resistance model that manifests islet hyperplasia. Using proteomics we show that serpinB1, a protease inhibitor, which is abundant in the hepatocyte secretome and sera derived from LIRKO mice, is the liver-derived secretory protein that regulates β cell proliferation in humans, mice, and zebrafish. Small-molecule compounds, that partially mimic serpinB1 effects of inhibiting Elastase activity, enhanced proliferation of β cells, and mice lacking serpinB1 exhibit attenuated β cell compensation in response to Insulin resistance. Finally, SerpinB1 treatment of islets modulated proteins in growth/survival pathways. Together, these data implicate serpinB1 as an endogenous protein that can potentially be harnessed to enhance functional β cell mass in patients with diabetes.