This is a competitive supplement in response to NOT-OD-09-058 (NIH Announces the Availability of Recovery Act Funds for Competitive Revision Applications). Diabetes is a metabolic disorder that currently affects over 180 million people worldwide. Common to all forms of diabetes is the gradual loss of functional insulin-producing ? cells in the endocrine pancreas. Thus, understanding the development, growth, survival and function of the endocrine pancreas may provide fundamental insight into treatments for this disease. Our studies have revealed that the Isl-1 transcription factor plays a crucial role in these processes in the endocrine pancreas. In our preliminary data, we show that a known Isl-1 co-regulator, Ldb1, is also required for the differentiation and/or function of endocrine cells. Thus, mutant mice lacking Ldb1 in the endocrine pancreas have no islet cells at 3 months of age and suffer from severe hyperglycemia. In contrary, mice with a germ-line deletion of closely related Ldb2 have no obvious phenotype. The effect of this Ldb1 mutant on islet cell formation is strikingly similar to our results with mice lacking Isl-1 in the endocrine pancreas. Based on these findings, we hypothesize that Ldb1 mediates Isl-1 action during islet cell development and in adult ? cell function. In a coordinated effort with Dr. Stein's laboratory at Vanderbilt University, we will 1) characterize Ldb1 and Ldb2 expression in the pancreas, 2) elucidate the role of Ldb1 in regulating endocrine cell development, and 3) examine how Ldb1 regulates adult ? cell function. CHOP contributes substantially to the local economy. In 2008, CHOP's operations created and supported over 16,882 jobs in the region, and CHOP's total economic impact was over $5.9 billion. Moreover, through a combination of private donations, NIH funding, and allocations from its hospital operations, CHOP receives more total research support than any other children's hospital in the United States--$180 million in fiscal year 2007-2008. This proposal will create four jobs (two at CHOP and two at Vanderbilt University). By doing so, funding this competitive supplement will expand the scope of my parent R01 and allow for job creation to improve our economy.

Public Health Relevance

HEALTH: Diabetes mellitus is a metabolic disorder that current affects over 180 million people worldwide. Replacement of lost or improperly functioning ?-cells represents the best possibility to cure, treat, or prevent diabetes. The experiments described in this application will help delineate the mechanisms controlling the growth and development of ?-cells and bring us closer to generating functional ?-cells for cell replacement therapy.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
3R01DK078606-02S1
Application #
7816348
Study Section
Special Emphasis Panel (ZRG1-EMNR-B (95))
Program Officer
Sato, Sheryl M
Project Start
2007-07-01
Project End
2011-08-31
Budget Start
2009-09-30
Budget End
2011-08-31
Support Year
2
Fiscal Year
2009
Total Cost
$820,936
Indirect Cost
Name
Children's Hospital of Philadelphia
Department
Type
DUNS #
073757627
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
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Terry, Natalie A; Walp, Erik R; Lee, Randall A et al. (2014) Impaired enteroendocrine development in intestinal-specific Islet1 mouse mutants causes impaired glucose homeostasis. Am J Physiol Gastrointest Liver Physiol 307:G979-91
Ediger, Benjamin N; Du, Aiping; Liu, Jingxuan et al. (2014) Islet-1 Is essential for pancreatic ?-cell function. Diabetes 63:4206-17
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Hunter, Chad S; Dixit, Shilpy; Cohen, Tsadok et al. (2013) Islet ýý-, ýý-, and ýý-cell development is controlled by the Ldb1 coregulator, acting primarily with the islet-1 transcription factor. Diabetes 62:875-86
Wilcox, Crystal L; Terry, Natalie A; May, Catherine Lee (2013) Arx polyalanine expansion in mice leads to reduced pancreatic ?-cell specification and increased ?-cell death. PLoS One 8:e78741
Liu, Jingxuan; Walp, Erik R; May, Catherine Lee (2012) Elevation of transcription factor Islet-1 levels in vivo increases ýý-cell function but not ýý-cell mass. Islets 4:199-206
Du, Aiping; McCracken, Kyle W; Walp, Erik R et al. (2012) Arx is required for normal enteroendocrine cell development in mice and humans. Dev Biol 365:175-88

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