Years ago, I learned that I had to periodically go for blood draws in order for my physician to obtain an accurate assessment of my blood chemistry. I expected the regular scolding about my elevated glucose levels, but beyond that, everything was usually normal. Good information was obtained for sure, and the short amount of discomfort I experienced was well-worth the information obtained from the standard tests.
Over the last few years, a great deal of work has been done on the exosomes present in the blood. It has been found that 93 percent of amplifiable cell-free DNA (cfDNA) is present within plasma exosomes, and this cfDNA can be amplified and used in clinical diagnostic procedures.
Beyond cfDNA, the presence of MicroRNA (miRNA) and protein within plasma exosomes can be exploited as a diagnostic tool. In one study, miRNA-21 and miRNA-1246 were present at higher levels in breast cancer patients compared to healthy controls2. In another study, blood plasma exosomes from Type 1 diabetes patients contained miRNA signatures that could be used to diagnose their ailment3. Turning away from genetic material within exosomes, exosomal protein may prove to be a tool for cancer diagnosis4.
Aside from using blood exosomes as diagnostic tools, they can also be put to work in the fight against disease. They have been loaded with small interfering RNA (siRNA) and used to transfer their cargo to monocytes and lymphocytes5. In another study, plasma exosomes were used directly as a means of protecting heart tissue after cardiac ischemia-reperfusion injury6.
Experimentation with blood exosomes is still in its infancy and the future of exosome diagnostics and treatment is bright. I feel that breakthroughs are around the corner, and new tools will be available to diagnose and treat human disease. At EriVan bio, it is our hope that our human plasma exosomes can be used in research that will result in new clinical applications.
Fernando MR, Jiang C, Krzyzanowski GD, Ryan WL. New evidence that a large proportion of human blood plasma cell-free DNA is localized in exosomes. PLoS One. 2017;12(8):e0183915. Published 2017 Aug 29. doi:10.1371/journal.pone.0183915
Hannafon BN, Trigoso YD, Calloway CL, et al. Plasma exosome microRNAs are indicative of breast cancer. Breast Cancer Res. 2016;18(1):90. Published 2016 Sep 8. doi:10.1186/s13058-016-0753-x
Garcia-Contreras M, Shah SH, Tamayo A, et al. Plasma-derived exosome characterization reveals a distinct microRNA signature in long duration Type 1 diabetes. Sci Rep. 2017;7(1):5998. Published 2017 Jul 20. doi:10.1038/s41598-017-05787-y
Li W, Li C, Zhou T, et al. Role of exosomal proteins in cancer diagnosis. Mol Cancer. 2017;16(1):145. Published 2017 Aug 29. doi:10.1186/s12943-017-0706-8
Wahlgren J, De L Karlson T, Brisslert M, et al. Plasma exosomes can deliver exogenous short interfering RNA to monocytes and lymphocytes. Nucleic Acids Res. 2012;40(17):e130. doi:10.1093/nar/gks463
Jose M. Vicencio, Derek M. Yellon, Vivek Sivaraman, Debashish Das, Claire Boi-Doku, Sapna Arjun, Ying Zheng, Jaime A. Riquelme, Jessica Kearney, Vikram Sharma, Gabriele Multhoff, Andrew R. Hall, Sean M. Davidson. Plasma Exosomes Protect the Myocardium From Ischemia-Reperfusion Injury. Journal of the American College of Cardiology Apr 2015, 65 (15) 1525-1536; DOI: 10.1016/j.jacc.2015.02.026