Urea impairs β cell glycolysis and insulin secretion in chronic kidney disease
Laetitia Koppe, … , Julien Ghislain, Vincent Poitout
Laetitia Koppe, … , Julien Ghislain, Vincent Poitout
Published September 1, 2016; First published August 15, 2016
Citation Information: J Clin Invest. 2016;126(9):3598-3612. https://doi.org/10.1172/JCI86181.
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Categories: Research Article Nephrology

Urea impairs β cell glycolysis and insulin secretion in chronic kidney disease

Abstract

Disorders of glucose homeostasis are common in chronic kidney disease (CKD) and are associated with increased mortality, but the mechanisms of impaired insulin secretion in this disease remain unclear. Here, we tested the hypothesis that defective insulin secretion in CKD is caused by a direct effect of urea on pancreatic β cells. In a murine model in which CKD is induced by 5/6 nephrectomy (CKD mice), we observed defects in glucose-stimulated insulin secretion in vivo and in isolated islets. Similarly, insulin secretion was impaired in normal mouse and human islets that were cultured with disease-relevant concentrations of urea and in islets from normal mice treated orally with urea for 3 weeks. In CKD mouse islets as well as urea-exposed normal islets, we observed an increase in oxidative stress and protein O-GlcNAcylation. Protein O-GlcNAcylation was also observed in pancreatic sections from CKD patients. Impairment of insulin secretion in both CKD mouse and urea-exposed islets was associated with reduced glucose utilization and activity of phosphofructokinase 1 (PFK-1), which could be reversed by inhibiting O-GlcNAcylation. Inhibition of O-GlcNAcylation also restored insulin secretion in both mouse models. These results suggest that insulin secretory defects associated with CKD arise from elevated circulating levels of urea that increase islet protein O-GlcNAcylation and impair glycolysis.

Authors

Laetitia Koppe, Elsa Nyam, Kevin Vivot, Jocelyn E. Manning Fox, Xiao-Qing Dai, Bich N. Nguyen, Dominique Trudel, Camille Attané, Valentine S. Moullé, Patrick E. MacDonald, Julien Ghislain, Vincent Poitout

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Figure 1

CKD mice have defective glucose-stimulated insulin secretion in vivo.

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CKD mice have defective glucose-stimulated insulin secretion in vivo. (A...
(A) Blood glucose and (B) AUC during an IPGTT (1 g/kg) in CKD or sham-operated mice. (C) Insulin levels during the IPGTT (n = 9–10). (D) Glucose levels during HGCs. (E) Insulin levels during HGCs and in response to an arginine bolus (1 mM/kg). (F) Mean insulin levels during the clamp (50–80 min). (G) Arginine-induced insulin secretion (AUC) from 80 to 90 minutes (n = 7). (H) Mean C-peptide during the clamp (50–80 min). (I) GIR during the clamp (50–80 min). Blood glucose (J) and kITT (K) during the IPITT (0.5 IU/kg) (n = 6–8). Data represent the mean ± SEM. *P < 0.05 and **P < 0.01 versus CKD for the same times; 2-way ANOVA with Bonferroni’s post-hoc test for A, C, D, E, and J and Student’s t test for B, F–I, and K.