Goal of this work is to understand why pancreatic -cells fail with an eye toward identifying genetic, biochemical, and cellular pathways that can be exploited asdrug targets to prevent and reverse this disease process. During its ten-year life, this grant has suppoted original observations identifying a homeostatic loop orchestrated by transcription factor FoxO1 tha integrates hormonal and nutrient signals into a gene expression program to preserve -cell function and lineage stability. Signal achievements of the last funding cycle have been the demonstration that -cell failure, long held to be secondary to loss of -cells to apoptosis, is due to -cell dediffeentiation into endocrine progenitor-like cells that express Neurogenin3, and their partial conversion into oter hormone-producing cells. In preliminary data presented to support a continuation of these studies, he PI shows that mice lacking FoxO1, 3a, and 4 in pancreatic progenitors or differentiated -cells devlop MODY, with striking abnormalities of the transcriptional networks regulated by Hnf4a, Hnf1a, and Pd1. Transcriptome analyses of the different mutants suggest a model in which FoxO control metabolic flexibility in differentiated -cells, and acquisition of glucose competence in maturing -cells. Te PI seeks continuing support for this work in three interrelated aims.
In Aim 1 the PI will investigatethe reversibility and prevention of -cell dedifferentiation, using genetic, pharmacological, and developmental tools. To this end, the PI will use a robust model of insulin-resistant diabetes, speifically developed to aid this work. In preliminary data to support Aim 2, the PI shows that triple knockoutof Foxo1, 3a, and 4 in -cells impair insulin secretion, results in mitochondrial dysfunction, impaire formation and trafficking of intracellular vesicles, reduced Ca signaling and branched chain amino cid metabolism, and increased lipid oxidation. The PI proposes to test the hypothesis that FoxO regulat the -cell's metabolic flexibility, i.e. the ability to select between glucose and non-glucose secretagogues as energy sources for mitochondrial ATP synthesis required for insulin secretion. In im 3, comparative transcriptome analyses of FoxO-deficient pancreatic progenitors vs. differentiated -cells reveal that genes required for glucose uptake and metabolism are affected in the former, but ot in the latter. The PI hypothesizes that this gene set is specifically regulated by FoxO in maturing -cells, and bestows on -cells glucose competence, i.e. the ability to properly sense glucose that is requied for -cell maturation. The PI proposes to use a combination of developmental and epigenetic analyse coupled with candidate gene approaches to understand the mechanism by which FoxO control -cell maturation.

Public Health Relevance

-cell dysfunction is a key factor in the progression of type 2 diabetes as well as an unmet treatment need. Studies supported by this grant have led to a reassessment of mechanisms of -cell failure, and suggested novel alternative approaches to its treatment. The work proposed leverages key advances in the cellular and developmental biology of failing -cells made during the past funding cycle to articulate the hypothesis that -cell rest an redifferentiation be tested as an innovative approach to -cell failure.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
4R01DK064819-14
Application #
9035385
Study Section
Cellular Aspects of Diabetes and Obesity Study Section (CADO)
Program Officer
Sato, Sheryl M
Project Start
2003-07-01
Project End
2017-04-30
Budget Start
2016-05-01
Budget End
2017-04-30
Support Year
14
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Columbia University (N.Y.)
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
621889815
City
New York
State
NY
Country
United States
Zip Code
10032
Accili, Domenico (2018) Insulin Action Research and the Future of Diabetes Treatment: The 2017 Banting Medal for Scientific Achievement Lecture. Diabetes 67:1701-1709
Haeusler, Rebecca A; McGraw, Timothy E; Accili, Domenico (2018) Biochemical and cellular properties of insulin receptor signalling. Nat Rev Mol Cell Biol 19:31-44
Kitamoto, Takumi; Sakurai, Kenichi; Lee, Eun Young et al. (2018) Distinct roles of systemic and local actions of insulin on pancreatic ?-cells. Metabolism 82:100-110
Ishida, Emi; Kim-Muller, Ja Young; Accili, Domenico (2017) Pair Feeding, but Not Insulin, Phloridzin, or Rosiglitazone Treatment, Curtails Markers of ?-Cell Dedifferentiation in db/db Mice. Diabetes 66:2092-2101
Langlet, Fanny; Haeusler, Rebecca A; Lindén, Daniel et al. (2017) Selective Inhibition of FOXO1 Activator/Repressor Balance Modulates Hepatic Glucose Handling. Cell 171:824-835.e18
Kim-Muller, Ja Young; Fan, Jason; Kim, Young Jung R et al. (2016) Aldehyde dehydrogenase 1a3 defines a subset of failing pancreatic ? cells in diabetic mice. Nat Commun 7:12631
Kim-Muller, Ja Young; Kim, Young Jung R; Fan, Jason et al. (2016) FoxO1 Deacetylation Decreases Fatty Acid Oxidation in ?-Cells and Sustains Insulin Secretion in Diabetes. J Biol Chem 291:10162-72
Cinti, Francesca; Bouchi, Ryotaro; Kim-Muller, Ja Young et al. (2016) Evidence of ?-Cell Dedifferentiation in Human Type 2 Diabetes. J Clin Endocrinol Metab 101:1044-54
Accili, D; Talchai, S C; Kim-Muller, J Y et al. (2016) When ?-cells fail: lessons from dedifferentiation. Diabetes Obes Metab 18 Suppl 1:117-22
Kuo, Taiyi; Kim-Muller, Ja Young; McGraw, Timothy E et al. (2016) Altered Plasma Profile of Antioxidant Proteins as an Early Correlate of Pancreatic ? Cell Dysfunction. J Biol Chem 291:9648-56

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