Role of Alpha-to-beta Cell Communication to Adapt Insulin Secretion to Insulin Resistance.

Summary

Glucagon secretion from α-cells has long been viewed as primarily a counterregulatory mechanism - e.g. an agent with a role to prevent blood sugar from decreasing to levels that compromise function. Our group, along with other researchers, have begun to identify a much more complex role for α-cells, raising questions about when and how glucagon may influence blood glucose levels. This proposal looks to detail proglucagon peptide secretion from α-cells and the impact this has on β-cell function and glucose tolerance, in preclinical studies of human islets and translational studies in human subjects. This protocol registration describes Aim 2 from this NIH grant which involves 2 study populations and separate protocols but addresses a common question. Aim 3 in the grant is focused on a separate hypothesis and will be conducted and published separately from Aim 2.

Timeline

Start

2025-12-30

Primary completion

2027-12

Completion

2027-12

Publications

• Background Ryan AS, Muller DC, Elahi D. Sequential hyperglycemic-euglycemic clamp to assess beta-cell and peripheral tissue: studies in female athletes. J Appl Physiol (1985). 2001 Aug;91(2):872-81. doi: 10.1152/jappl.2001.91.2.872.
• Background Jensen DH, Aaboe K, Henriksen JE, Volund A, Holst JJ, Madsbad S, Krarup T. Steroid-induced insulin resistance and impaired glucose tolerance are both associated with a progressive decline of incretin effect in first-degree relatives of patients with type 2 diabetes. Diabetologia. 2012 May;55(5):1406-16. doi: 10.1007/s00125-012-2459-7.
• Background Salehi M, Vahl TP, D'Alessio DA. Regulation of islet hormone release and gastric emptying by endogenous glucagon-like peptide 1 after glucose ingestion. J Clin Endocrinol Metab. 2008 Dec;93(12):4909-16. doi: 10.1210/jc.2008-0605. Epub 2008 Sep 30.
• Background Gray SM, Goonatilleke E, Emrick MA, Becker JO, Hoofnagle AN, Stefanovski D, He W, Zhang G, Tong J, Campbell J, D'Alessio DA. High Doses of Exogenous Glucagon Stimulate Insulin Secretion and Reduce Insulin Clearance in Healthy Humans. Diabetes. 2024 Mar 1;73(3):412-425. doi: 10.2337/db23-0201.
• Background Schirra J, Sturm K, Leicht P, Arnold R, Goke B, Katschinski M. Exendin(9-39)amide is an antagonist of glucagon-like peptide-1(7-36)amide in humans. J Clin Invest. 1998 Apr 1;101(7):1421-30. doi: 10.1172/JCI1349.
• Background Salehi M, Aulinger B, Prigeon RL, D'Alessio DA. Effect of endogenous GLP-1 on insulin secretion in type 2 diabetes. Diabetes. 2010 Jun;59(6):1330-7. doi: 10.2337/db09-1253. Epub 2010 Mar 9.

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