Date: Tuesday, May 2, 2017
Session Name: Poster Session D: Diagnostics/Biomarkers Session II
Session Time: 6:00pm-7:00pm
Presentation Time: 6:00pm-7:00pm
Location: Hall D1
Introduction: A significant mass of intraportally transplanted islets undergo damage due to various stress conditions including hypoxia and inflammation. Development of innovative ultrasensitive tests to accurately measure islet damage during specific stress condition will facilitate development of strategies to minimize islet damage. Exosomes are circulating cell-derived nanoparticles containing proteins and nucleic acids with a wide range of stimulatory and inhibitory functions. Here, we profiled the microRNA signature in exosomes released from human islets undergoing damage due to hypoxia and/or proinflammatory cytokines using next-generation sequencing.
Methods: Purified human islets were subjected to normoxia or hypoxia or cytokines cocktail or both for 24 hrs. The exosomes released were isolated using Total Exosome Isolation kit and characterized based on surface markers. Total RNA was isolated from exosomes and single end sequencing (1 X 35 nt) on an Illumina NextSeq was performed. Cytokines in exosomes were quantified using Luminex multiplex assay.
Results: The size of islet-derived exosomes ranged between 30-100nm and showed positive expression of tetraspanin surface markers CD9 and CD63 in western blots. About 190 miRNA transcripts were differentially expressed between cytokine, hypoxia and cytokine + hypoxia when compared to the control (p<= 0.05, FC>1.5). Among 190 miRNAs, 14 miRNAs were significantly increased under cytokine treatment, 52 miRNAs during hypoxia and 33 miRNAs under both conditions. 11 miRNAs were released under both stresses when compared to the control (p<= 0.05, FC>1.5). MiRNA-375 was abundantly expressed (log2 CPM=18±0.6) in the exosomes released from all samples including controls. Compared to the control and hypoxic treatment, cytokine cocktail treated islets released significantly more IP10, MCP1, IL6 and IL8 in the exosomes (p<0.001).
Conclusion: This study has identified specific exosomal miRNAs released by islets undergoing different stress conditions such as hypoxia and/or proinflammatory cytokines. Measurement of such biomarker miRNAs in blood samples collected during islet transplantation reveal the mechanisms underlying damage to transplanted islets.
CITATION INFORMATION: Saravanan P, Gu J, Wang X, Nguyen P, Yoshimatsu G, Lawrence M, Naziruddin B. Next-Generation Sequencing-Based Exosome MicroRNA Profiling for Specific Identification of Islet Damage. Am J Transplant. 2017;17 (suppl 3).
To cite this abstract in AMA style:Saravanan P, Gu J, Wang X, Nguyen P, Yoshimatsu G, Lawrence M, Naziruddin B. Next-Generation Sequencing-Based Exosome MicroRNA Profiling for Specific Identification of Islet Damage. [abstract]. Am J Transplant. 2017; 17 (suppl 3). https://atcmeetingabstracts.com/abstract/next-generation-sequencing-based-exosome-microrna-profiling-for-specific-identification-of-islet-damage/. Accessed August 14, 2020.
« Back to 2017 American Transplant Congress