Hepatic and glucagon-like peptide-1–mediated reversal of diabetes by glucagon receptor antisense oligonucleotide inhibitors
Kyle W. Sloop, … , Lynnetta M. Watts, M. Dodson Michael
Kyle W. Sloop, … , Lynnetta M. Watts, M. Dodson Michael
Published June 1, 2004
Citation Information: J Clin Invest. 2004;113(11):1571-1581. https://doi.org/10.1172/JCI20911.
View: Text | PDF
Article Metabolism

Hepatic and glucagon-like peptide-1–mediated reversal of diabetes by glucagon receptor antisense oligonucleotide inhibitors

Abstract

Uncontrolled hepatic glucose production contributes significantly to hyperglycemia in patients with type 2 diabetes. Hyperglucagonemia is implicated in the etiology of this condition; however, effective therapies to block glucagon signaling and thereby regulate glucose metabolism do not exist. To determine the extent to which blocking glucagon action would reverse hyperglycemia, we targeted the glucagon receptor (GCGR) in rodent models of type 2 diabetes using 2′-methoxyethyl–modified phosphorothioate-antisense oligonucleotide (ASO) inhibitors. Treatment with GCGR ASOs decreased GCGR expression, normalized blood glucose, improved glucose tolerance, and preserved insulin secretion. Importantly, in addition to decreasing expression of cAMP-regulated genes in liver and preventing glucagon-mediated hepatic glucose production, GCGR inhibition increased serum concentrations of active glucagon-like peptide-1 (GLP-1) and insulin levels in pancreatic islets. Together, these studies identify a novel mechanism whereby GCGR inhibitors reverse the diabetes phenotype by the dual action of decreasing hepatic glucose production and improving pancreatic β cell function.

Authors

Kyle W. Sloop, Julia Xiao-Chun Cao, Angela M. Siesky, Hong Yan Zhang, Diane M. Bodenmiller, Amy L. Cox, Steven J. Jacobs, Julie S. Moyers, Rebecca A. Owens, Aaron D. Showalter, Martin B. Brenner, Achim Raap, Jesper Gromada, Brian R. Berridge, David K. B. Monteith, Niels Porksen, Robert A. McKay, Brett P. Monia, Sanjay Bhanot, Lynnetta M. Watts, M. Dodson Michael

×

Figure 8

Options: View larger image (or click on image) Download as PowerPoint
GCGR ASO treatment increases islet GLP-1 and insulin content. (A) Islets...
GCGR ASO treatment increases islet GLP-1 and insulin content. (A) Islets were isolated as described in Methods from 12-week-old male db/db mice (n = 5–6 per treatment group), which had been treated twice per week (every 3.5 days) by subcutaneous injection with saline (black bar) or GCGR ASO 180475 (white bar) at 25 mg/kg for a total of 9 doses. Five replicates of 10 islets from each animal were extracted with acid ethanol overnight at 4–C, and GLP-1 was assayed by ELISA. Results are expressed as mean ± SEM. P < 0.05. (B) Islet insulin content was assayed by RIA using samples prepared as described in (A). Results are expressed as mean ± SEM. P < 0.05. (C) Real-time quantitative RT-PCR was used to profile gene expression from islets of 10-week-old male db/db mice (n = 9 per treatment group), which had been treated twice per week (every 3.5 days) by subcutaneous injection with saline (black bar) or GCGR ASO 180475 (white bar) at 25 mg/kg for a total of 9 doses. Islets were isolated as described in Methods, and 200 islets from 3 individuals were pooled to give one sample for RNA extraction. Islet GCGR, preproglucagon (proGCG), Brain-4 (Brn4), and insulin-1 (Ins1) levels showed significant differences when compared to saline-treated animals (P < 0.05 using Student’s t test). Differences in the mRNA levels of insulin-2 (Ins2), glucose transporter-2 (Glut2) and glucokinase (GCK) were not observed. Mouse 36B4 ribosomal phosphoprotein mRNA was measured and used to normalize RNA. Data are the mean values ± SEM of 3 samples per treatment group.