A hallmark of Type 2 diabetes is impaired insulin secretion from beta cells of the islets of Langerhans. Greater understanding of islets and insulin secretion is of fundamental importance in determining the root causes of diabetes and developing potential treatments. Studies of islets are critically dependent upon instrumentation that can detect their biochemical and physiological dynamics. Type 1 diabetes is characterized by autoimmune attack on beta cells and subsequent loss of insulin secretion. A promising treatment for type 1 diabetes is transplant of islets;however, this treatment is presently limited by inability to adequately assess islets used in transplant. Therefore, improved tools for studying insulin secretion are crucial for advancing treatments of diabetes. The overall objective of this work is to develop advanced instrumentation suitable for measuring chemical events related to peptide secretion from islets of Langerhans. Our first two aims are to develop microfluidic tools that will allow single islets to be cultured while simultaneously monitoring hormone and metabolite secretion and metabolism. To allow cell-cell interactions to be studied, the microfluidic chip will incorporate a microcirculatory system that allows two different cell types to be cultured and interact during the measurements.
Our third aim i s to develop high-throughput metabolomic methods for measurement of polar and lipidic metabolites present in insulin-secreting cells. The method will be based on capillary liquid chromatography and capillary electrophoresis with mass spectrometry detection. Throughput of this method will be enhanced through novel fluidic methods and improved data analysis.
Our final aim i s to use these methods in studies that will: 1) determine metabolites involved in fuel-stimulated insulin secretion;2) how islet cells are influenced by fat and liver cells;3) the role of leptin and PPARg receptors in regulating lipid metabolism in islets;and 4) mechanisms of islet oscillations. The methods will also be used in pilot studies to determine if they may be useful assessing islets prior to transplant. These methods will offer new opportunities for studying the root causes of diabetes and devising novel treatments.

Public Health Relevance

Diabetes is an enormous public health problem costing over $100 billion in 2002 in the US. This disease is characterized by impaired insulin secretion from cell clusters known as islets of Langerhans. Our research will result in novel instrumentation that will allow studies ofthe chemical changes associated with normal and diseased islet function in unprecedented detail. Assessment of such chemical changes is expected to help identify novel theraneutic targets.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
3R37DK046960-22S1
Application #
8810348
Study Section
Special Emphasis Panel (NSS)
Program Officer
Sato, Sheryl M
Project Start
1993-09-30
Project End
2016-03-31
Budget Start
2014-04-01
Budget End
2015-03-31
Support Year
22
Fiscal Year
2014
Total Cost
$87,080
Indirect Cost
$31,080
Name
University of Michigan Ann Arbor
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Karra, Sushma; Griffith, Wendell P; Kennedy, Robert T et al. (2016) Hormone glucagon: electrooxidation and determination at carbon nanotubes. Analyst 141:2405-11
Schmudlach, Andrew; Felton, Jeremy; Cipolla, Cynthia et al. (2016) Sample preparation protocol for bottom-up proteomic analysis of the secretome of the islets of Langerhans. Analyst 141:1700-6
Glynn, Eric; Thompson, Benjamin; Vadrevu, Suryakiran et al. (2016) Chronic Glucose Exposure Systematically Shifts the Oscillatory Threshold of Mouse Islets: Experimental Evidence for an Early Intrinsic Mechanism of Compensation for Hyperglycemia. Endocrinology 157:611-23
Zhu, Shuaishuai; Larkin, Dennis; Lu, Shusheng et al. (2016) Monitoring C-Peptide Storage and Secretion in Islet β-Cells In Vitro and In Vivo. Diabetes 65:699-709
ElAzzouny, Mahmoud A; Evans, Charles R; Burant, Charles F et al. (2015) Metabolomics Analysis Reveals that AICAR Affects Glycerolipid, Ceramide and Nucleotide Synthesis Pathways in INS-1 Cells. PLoS One 10:e0129029
Dugan, Colleen E; Cawthorn, William P; MacDougald, Ormond A et al. (2014) Multiplexed microfluidic enzyme assays for simultaneous detection of lipolysis products from adipocytes. Anal Bioanal Chem 406:4851-9
Flak, Jonathan N; Patterson, Christa M; Garfield, Alastair S et al. (2014) Leptin-inhibited PBN neurons enhance responses to hypoglycemia in negative energy balance. Nat Neurosci 17:1744-50
Dugan, Colleen E; Kennedy, Robert T (2014) Measurement of lipolysis products secreted by 3T3-L1 adipocytes using microfluidics. Methods Enzymol 538:195-209
El-Azzouny, Mahmoud; Evans, Charles R; Treutelaar, Mary K et al. (2014) Increased glucose metabolism and glycerolipid formation by fatty acids and GPR40 receptor signaling underlies the fatty acid potentiation of insulin secretion. J Biol Chem 289:13575-88
Davda, Dahvid; El Azzouny, Mahmoud A; Tom, Christopher T M B et al. (2013) Profiling targets of the irreversible palmitoylation inhibitor 2-bromopalmitate. ACS Chem Biol 8:1912-7

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