Background: The prevalence of cannabis use and Cannabis Use Disorder (CUD) are highest amongst adolescents and young adults. A lack of brain tissues from patients with CUD limits the ability to examine the molecular basis of cannabis related neuropathology. Proteomic studies of neuron-derived extracellular vesicles (NDEs) isolated from the biofluids may reveal markers of neuropathology in CUD. Methods: NDEs were extracted using ExoSORT, an immunoaffinity method, from plasma samples of 10 patients with young onset CUD and 10 matched controls. Differential proteomic profiles of NDEs between groups was explored with Label Free Quantification (LFQ) mass spectrometry. Selected differentially abundant proteins were validated using orthogonal methods. Results: A total of 231 (+/- 10) unique proteins were identified in NDE preparations of which 28 were differentially abundant between groups. The difference in abundance properdin, encoded by the CFP gene surpassed the significance threshold after false discovery rate correction. Notably, SHANK1 (SH3 and multiple ankyrin repeat domains protein 1), an adapter protein at the post-synaptic density, was found to be depleted in the CUD compared to control NDE preparations. Discussion: The study shows that LFQ mass spectrometry proteomic analysis of NDEs derived from plasma may yield important insights into the synaptic pathology associated with CUD. Optimization of this approach may lead to a novel assay to study altered proteomic signalling in the brain using liquid biopsy in diverse neuropsychiatric syndromes.

The authors have declared no competing interest.

SG is supported by NARSAD young investigator award #27340 from the Brain and Behavior Research Foundation to study longitudinal effects of cannabis exposure in adolescents and young adults. The present work was additionally supported by a pilot award to study altered brain proteomic signalling in addiction by the Yale/NIDA Neuroproteomic Center (DA018343). ACN and T.T.L were also supported in part by the Yale/NIDA Neuroproteomics Center (DA018343). The Q-Exactive HFX mass spectrometer and M-class UPLC at the Keck MS & Proteomics Resource was supported in part by NIH SIG grants OD023651-01A1 and the Yale School of Medicine. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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