An orally available compound suppresses glucagon hypersecretion and normalizes hyperglycemia in type 1 diabetes
Farzad Asadi, Subhadra C. Gunawardana, Roland E. Dolle, David W. Piston
Farzad Asadi, Subhadra C. Gunawardana, Roland E. Dolle, David W. Piston
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Research Article Endocrinology

An orally available compound suppresses glucagon hypersecretion and normalizes hyperglycemia in type 1 diabetes

Abstract

Suppression of glucagon hypersecretion can normalize hyperglycemia during type 1 diabetes (T1D). Activating erythropoietin-producing human hepatocellular receptor type-A4 (EphA4) on α cells reduced glucagon hypersecretion from dispersed α cells and T1D islets from both human donor and mouse models. We synthesized a high-affinity small molecule agonist for the EphA4 receptor, WCDD301, which showed robust plasma and liver microsome metabolic stability in both mouse and human preparations. In islets and dispersed islet cells from nondiabetic and T1D human donors, WCDD301 reduced glucagon secretion comparable to the natural EphA4 ligand, Ephrin-A5. In diabetic NOD and streptozotocin-treated mice, once-daily oral administration of WCDD301 formulated with a time-release excipient reduced plasma glucagon and normalized blood glucose for more than 3 months. These results suggest that targeting the α cell EphA4 receptor by sustained release of WCDD301 is a promising pharmacologic pathway for normalizing hyperglycemia in patients with T1D.

Authors

Farzad Asadi, Subhadra C. Gunawardana, Roland E. Dolle, David W. Piston

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Figure 1

High binding affinity of WCDD301 for EphA4 receptor in a competitive way that suppresses glucagon secretion without side effect on insulin secretion.

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High binding affinity of WCDD301 for EphA4 receptor in a competitive way...
(A) Structural formula of WCDD301. (B) Determining binding affinity of WCDD301 for EphA4 without global fitting; each curve demonstrates best fit values of 3 individual replicates. (C) Determining binding affinity of WCDD301 for EphA4 via Cheng-Prusoff equation; each curve demonstrates best fit values of 3 individual replicates. (D) Demonstrating competition between WCDD301 and Ephrin-A5 Fc concentrations for binding to a fixed level of EphA4 (3 μg/mL) in ELISA system via AUC analysis. Values (mean ± SD) of AUC at 2 nM (0.025 ± 0.0011 AU), 4 nM (0.0469 ± 0.0014 AU), 6 nM (0.0554 ± 0.0006 AU), and 8 nM (0.0617 ± 0.0011 AU) of WCDD301 were compared; *** indicates difference of P < 0.001 between each successive concentration of Ephrin-A5 Fc (n = 3). (E) Competition between WCDD301 and Ephrin-A5 Fc for binding to a fixed level of EphA4 (3 μg/mL) through Michaelis-Menten kinetics; Ki values (n = 3) of WCDD301 challenges were compared with the 0 μM of WCDD301. Relative secretion of (F) glucagon and (G) insulin in murine dispersed islet cells in the presence and absence of WCDD301 or Ephrin-A5 Fc (E). Values of treatment groups were compared with the respective control; each dot demonstrates values (mean ± SD) of a single mouse (n = 5). (H) Secretion of glucagon in murine dispersed islet cells following cotreatment of WCDD301 with an EphA4 antagonist, rhyncophylline (Rhy). Values of treatment groups were compared with the corresponding controls; each dot demonstrates values (mean ± SD) of a single mouse (n = 5). In all experiments, values (mean ± SEM) were compared using 1-way ANOVA, α = 0.05. *P < 0.05, **P < 0.01, ***P < 0.001.