Inhibition of the eukaryotic initiation factor-2α kinase PERK decreases risk of autoimmune diabetes in mice
Charanya Muralidharan, … , Sarah A. Tersey, Raghavendra G. Mirmira
Charanya Muralidharan, … , Sarah A. Tersey, Raghavendra G. Mirmira
Published June 18, 2024
Citation Information: J Clin Invest. 2024;134(16):e176136. https://doi.org/10.1172/JCI176136.
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Research Article Endocrinology

Inhibition of the eukaryotic initiation factor-2α kinase PERK decreases risk of autoimmune diabetes in mice

Abstract

Preventing the onset of autoimmune type 1 diabetes (T1D) is feasible through pharmacological interventions that target molecular stress–responsive mechanisms. Cellular stresses, such as nutrient deficiency, viral infection, or unfolded proteins, trigger the integrated stress response (ISR), which curtails protein synthesis by phosphorylating eukaryotic translation initiation factor-2α (eIF2α). In T1D, maladaptive unfolded protein response (UPR) in insulin-producing β cells renders these cells susceptible to autoimmunity. We found that inhibition of the eIF2α kinase PKR-like ER kinase (PERK), a common component of the UPR and ISR, reversed the mRNA translation block in stressed human islets and delayed the onset of diabetes, reduced islet inflammation, and preserved β cell mass in T1D-susceptible mice. Single-cell RNA-Seq of islets from PERK-inhibited mice showed reductions in the UPR and PERK signaling pathways and alterations in antigen-processing and presentation pathways in β cells. Spatial proteomics of islets from these mice showed an increase in the immune checkpoint protein programmed death-ligand 1 (PD-L1) in β cells. Golgi membrane protein 1, whose levels increased following PERK inhibition in human islets and EndoC-βH1 human β cells, interacted with and stabilized PD-L1. Collectively, our studies show that PERK activity enhances β cell immunogenicity and that inhibition of PERK may offer a strategy for preventing or delaying the development of T1D.

Authors

Charanya Muralidharan, Fei Huang, Jacob R. Enriquez, Jiayi E. Wang, Jennifer B. Nelson, Titli Nargis, Sarah C. May, Advaita Chakraborty, Kayla T. Figatner, Svetlana Navitskaya, Cara M. Anderson, Veronica Calvo, David Surguladze, Mark J. Mulvihill, Xiaoyan Yi, Soumyadeep Sarkar, Scott A. Oakes, Bobbie-Jo M. Webb-Robertson, Emily K. Sims, Kirk A. Staschke, Decio L. Eizirik, Ernesto S. Nakayasu, Michael E. Stokes, Sarah A. Tersey, Raghavendra G. Mirmira

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Figure 1

The UPR and ISR are active in prediabetic NOD mice and proinflammatory cytokine–treated human islets.

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The UPR and ISR are active in prediabetic NOD mice and proinflammatory c...
(A) UMAP embeddings of a reanalysis of scRNA-Seq of islets from female NOD mice. (B) GSEA of the endocrine cell population identified in A for UPR. (C) UMAP embeddings of a reanalysis of scRNA-Seq of islets from female NOD mice. (D) GSEA of the β cell population identified in C for UPR. (E) Representative immunoblot of p-eIF2α and total eIF2α; n = 3 biological replicates. (F) Quantification of the immunoblots in E (ANOVA). (G) Representative images of pancreas immunostained as indicated. Scale bars: 50 μm. Dotted lines indicate islets. (H) Quantification of the images in G; each dot represents an islet from n = 3 mice (distinguished by color), with mean values of each mouse shown (ANOVA of means). (I) Representative puromycin immunoblot image (left panel) and corresponding total protein stain (right panel) from islets of 8-week-old female mouse islets. (J) Quantification of the puromycin intensity normalized to total protein stain from I; n = 3 (each replicate represents pooled islets from 3–4 mice) (ANOVA). (K) Representative immunoblot of p-PERK and total PERK from islets of 8-week-old female mice. (L) Quantification of the immunoblot for p-PERK normalized to total PERK from n = 4 (each replicate represents pooled islets from 3–4 mice). (M) Representative puromycin incorporation immunoblot (left panel) and corresponding total protein stain (right panel) from MIN6 cells treated as indicated. (N) Quantification of the puromycin intensity normalized to total protein stain from L; n = 3 independent experiments (RM-ANOVA). PIC, proinflammatory cytokine. (O) Polyribosomal profiling traces of human islets treated as indicated. Data are represented as mean ± SEM.