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 3

PERK inhibition increases levels of PD-L1 in β cells of NOD mice.

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PERK inhibition increases levels of PD-L1 in β cells of NOD mice. Predia...
Prediabetic female NOD mice (6 weeks of age) were treated with HC-5770 for 2 weeks, isolated islets were subjected to scRNA-Seq, and pancreas tissue was subjected to NanoString spatial proteomics. (A) UMAP embeddings of merged scRNA-Seq profiles from islets. n = 3 mice per group. (B) GO analysis of all cell clusters (pseudo-bulk analysis). (C) GSEA of β cell clusters showing UPR. (D) GSEA of β cell clusters showing PERK-meditated UPR. (E) Percentages of T, B, and myeloid cells identified within the immune cell clusters. (F) Percentages of α, β, δ, and PP cells identified within the islet cell clusters. (G) Example of the insulin-positive area and the insulitic area used to collect spatial tissue-based proteomics. (H) Heatmap of identified proteins in the insulitic area (left panel) and insulin-positive area (right panel); n = 10–11 ROI from 2 mice per group. *P < 0.05, t test. (I) Representative images of pancreata from mice following 2 weeks of treatment with vehicle or HC-5770 immunostained as indicated; dotted lines indicate islets. Scale bars: 50 μm. (J) Quantification of PD-L1 intensity in the β cells of I; each dot represents an islet from n = 4 mice (distinguished by color), with mean values of each mouse shown (t test for the means). (K) Six-week-old female NOD mice were treated as indicated with HC-5770 for 2 weeks, then administered either anti-PD-L1 or IgG control, followed by another 2 weeks of HC-5770 treatment; glucose was measured on alternate days after injection; n = 5 mice per group. (L) AUC analysis of the data in K (ANOVA). Data are represented as mean ± SEM.