Peripheral signature of altered synaptic integrity in young onset cannabis use disorder: A proteomic study of circulating extracellular vesicles

Abstract

Background

Rates of Cannabis Use Disorder (CUD) are highest amongst young adults. Paucity of brain tissue samples 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 to enrich NDEs from plasma samples from patients with young onset CUD and matched controls. Differential proteomic profiles were explored with Label Free Quantification (LFQ) mass spectrometry. Selected proteins were validated using orthogonal methods.

Results

A total of 231 (±10) proteins were identified in NDE preparations from CUD and controls of which 28 were differentially abundant between groups. The difference in abundance of properdin (CFP gene) was statistically significant. SHANK1 (SHANK1 gene), an adapter protein at the post-synaptic density, was nominally depleted in the CUD NDE preparations.

Conclusion

In this pilot study, we noted a decrease in SHANK1 protein, involved in the structural and functional integrity of glutamatergic post-synapse, a potential peripheral signature of CUD neuropathology. 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.

Keywords:

• Cannabis use disorder
• extracellular vesicle
• glutamate synapse
• proteomics
• mass spectrometry

Acknowledgements

We also like to thank Florine Collin and Weiwei Wang from the Keck MS & Proteomics Resource for their support on sample preparation and data collection, respectively.

Statement of interest

Dr. Erez Eitan and Dr. Katya Elgart, are working in NeuroDex INC, a for-profit company. Dr. Erez Eitan is also a shareholder in NeuroDex INC. Other authors declare that there are no conflicts of interest.

Additional information

Funding

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 TTL 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 were 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.