Application of EXODUS system combined with DNA nanoswitch in detection of miR-107 from plasma exosomes of Parkinson's patients

Objective This study aims to achieve rapid detection of Parkinson's disease (PD) plasma exosome microRNA. Methods A case-control design was used to collect 10 Parkinson's disease and 10 healthy control plasma samples from Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology from December 2023 to January 2024. Exosome detection via the ultrafast-isolation system (EXODUS) was used to isolate plasma exosomes, nanoparticle tracking analysis technology and electron microscopy were used to identify exosome particle size and morphology, Qiagen miRNeasy Micro Kit was used to extract RNA, microRNA activated conditional looping of engineered switches (miRacles) was used to detect miR-107, and the relative expression was analyzed by agarose gel electrophoresis. Thermo Fisher RevertAid RT Reverse Transcription Kit was used to perform reverse transcription of RNA, and real time PCR was used to detect miR-107. Independent samples t-test was used for comparison between groups. Results EXODUS system completed the isolation of exosomes from 500 μl plasma within 1.5 hours. Exosome concentration mean ± SD: control group: (4.82 ± 2.02) × 1010 particles / ml, PD group: (5.08 ± 2.34) × 1010 particles / ml, and there was no significant difference in exosome concentration between PD patients and healthy controls (t = -0.168, P = 0.872). The morphology of exosomes was confirmed by electron microscopy. The miRacles nanoswitch could detect fM-level miR-107 and could also effectively distinguish miR-107 from its family members, including miR-15a and miR-16. Agarose gel electrophoresis showed that mean ± SD of relative gray value content: control group: 1.00 ± 0.26, PD group: 1.86 ± 0.21, and miR-107 in the PD group was significantly higher than that in the control (P = 1.9E-7), which was consistent with the result of real time PCR. Conclusion EXODUS combined with miRacles can achieve rapid, non-enzymatic and cheap detection of plasma exosomal miR-107 in PD patients.