CHUNHUA DAI, AJAY K. SINGH, REBEKAH BRANTLEY, AMBER BRADLEY, REGINA JENKINS, DIANE C. SAUNDERS, MARCELA BRISSOVA, EREZ LEVANON, AGNES KLOCHENDLER, YUVAL DOR, ALVIN C. POWERS
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引用次数: 0
Abstract
Introduction & Objective: It is thought that viral infection triggers islet inflammation, an interferon signature, and autoimmunity resulting in type 1 diabetes. Despite extensive research, an inciting virus has not been identified. We hypothesized that impaired RNA editing and accumulation of double-stranded RNA in beta cells triggers an interferon response, causing islet inflammation, autoimmunity, and beta cell destruction. While RNA editing regulated by adenosine deaminases acting on RNA (ADAR) has been studied in some organs and in cancer, little is known about the role of ADAR in human islets. Method: To elucidate the role of ADAR1 in human islets, we first studied ADAR expression and distribution in human pancreas across postnatal developmental timeline (1 day, 4 months, 2, 6, 10, 35 years). Then we transduced human pseudoislets with a shRNA for ADAR and examined their function and gene expression. The transduced pseudoislets were also transplanted into NSG mice. Insulin secretion was measured and grafts were studied. Results: We found that ADAR1 expression at all ages was greater in endocrine cells than acinar cells. Using the shRNA approach, ADAR mRNA levels were reduced by 70% (n=11 donors). After 7-day culture, expression of dsRNA sensors, IFNB1, IRF7, IRF9, and interferon-stimulated genes was increased while INS and MAFA expression was reduced in ADAR knockdown islets without changes in insulin secretion. However, 3 weeks post transplantation, glucose/arginine-stimulated human insulin secretion was significantly decreased in mice with the ADAR shRNA graft compared with scrambled shRNA control graft (0.117 vs 0.300 ng/mL, p=0.0001, n=3 donors). Analysis of pseudoislet grafts 4 weeks after transplantation showed marked accumulation of mouse CD45+ cells around ADAR-knockdown islet grafts. Conclusion: Interruption of RNA editing in human islets activates the interferon signaling pathway leading to islet inflammation and beta cell dysfunction. Disclosure C. Dai: None. A.K. Singh: None. R. Brantley: None. A. Bradley: None. R. Jenkins: None. D.C. Saunders: None. M. Brissova: None. E. Levanon: Advisory Panel; ADARX, Exsilio. A. Klochendler: None. Y. Dor: None. A.C. Powers: None.
期刊介绍:
Diabetes is a scientific journal that publishes original research exploring the physiological and pathophysiological aspects of diabetes mellitus. We encourage submissions of manuscripts pertaining to laboratory, animal, or human research, covering a wide range of topics. Our primary focus is on investigative reports investigating various aspects such as the development and progression of diabetes, along with its associated complications. We also welcome studies delving into normal and pathological pancreatic islet function and intermediary metabolism, as well as exploring the mechanisms of drug and hormone action from a pharmacological perspective. Additionally, we encourage submissions that delve into the biochemical and molecular aspects of both normal and abnormal biological processes.
However, it is important to note that we do not publish studies relating to diabetes education or the application of accepted therapeutic and diagnostic approaches to patients with diabetes mellitus. Our aim is to provide a platform for research that contributes to advancing our understanding of the underlying mechanisms and processes of diabetes.