Journal
DIABETOLOGIA
Volume 61, Issue 5, Pages 1124-1134Publisher
SPRINGER
DOI: 10.1007/s00125-018-4559-5
Keywords
Beta cell signal transduction; Cell lines; Human; Prediction and prevention of type 1 diabetes
Categories
Funding
- NIDDK [K08DK103983]
- Pediatric Endocrine Society Clinical Scholar Award
- Center for Diabetes and Metabolic Diseases NIH/NIDDK [P30 DK097512]
- Indiana University Health
- Indiana Clinical and Translational Sciences Institute [UL1TR001108]
- Ralph W. and Grace M. Showalter research award
- JDRF
- NIH [32DK064466, 2UC4DK098085-02]
- Diabetes Research Center [P30 DK097512]
- NIDDK
Ask authors/readers for more resources
Aims/hypothesis Improved biomarkers are acutely needed for the detection of developing type 1 diabetes, prior to critical loss of beta cell mass. We previously demonstrated that elevated beta cell microRNA 21-5p (miR-21-5p) in rodent and human models of type 1 diabetes increased beta cell apoptosis. We hypothesised that the inflammatory milieu of developing diabetes may also increase miR-21-5p in beta cell extracellular vesicle (EV) cargo and that circulating EV miR-21-5p would be increased during type 1 diabetes development. Methods MIN6 and EndoC-beta H1 beta cell lines and human islets were treated with IL-1 beta, IFN-gamma and TNF-alpha to mimic the inflammatory milieu of early type 1 diabetes. Serum was collected weekly from 8-week-old female NOD mice until diabetes onset. Sera from a cross-section of 19 children at the time of type 1 diabetes diagnosis and 16 healthy children were also analysed. EVs were isolated from cell culture media or serum using sequential ultracentrifugation or ExoQuick precipitation and EV miRNAs were assayed. Results Cytokine treatment in beta cell lines and human islets resulted in a 1.5- to threefold increase in miR-21-5p. However, corresponding EVs were further enriched for this miRNA, with a three- to sixfold EV miR-21-5p increase in response to cytokine treatment. This difference was only partially reduced by pre-treatment of beta cells with Z-VAD-FMK to inhibit cytokine-induced caspase activity. Nanoparticle tracking analysis showed cytokines to have no effect on the number of EVs, implicating specific changes within EV cargo as being responsible for the increase in beta cell EV miR-21-5p. Sequential ultracentrifugation to separate EVs by size suggested that this effect was mostly due to cytokine-induced increases in exosome miR-21-5p. Longitudinal serum collections from NOD mice showed that EVs displayed progressive increases in miR-21-5p beginning 3 weeks prior to diabetes onset. To validate the relevance to human diabetes, we assayed serum from children with new-onset type 1 diabetes compared with healthy children. While total serum miR-21-5p and total serum EVs were reduced in diabetic participants, serum EV miR-21-5p was increased threefold compared with non-diabetic individuals. By contrast, both serum and EV miR-375-5p were increased in parallel among diabetic participants. Conclusions/interpretation We propose that circulating EV miR-21-5p may be a promising marker of developing type 1 diabetes. Additionally, our findings highlight that, for certain miRNAs, total circulating miRNA levels are distinct from circulating EV miRNA content.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available