Identification Of Protein Biomarker Of Persistent Vegetative State After Severe Traumatic Brain Injury Based On ITRAQ

Vegetative state(VS)is a complex condition with unclear mechanisms and limited diagnostic,prognostic and therapeutic methods.To investigate mechanisms underlying persistent vegetative state(PVS)after severe traumatic brain injury(s TBI)and identify tear proteins as potential biomarkers,we analyzed the tear proteome profile from patients with PVS after s TBI using i TRAQ quantitative proteomics.Tear samples collected from 16 patients with PVS after s TBI and 16 normal subjects were analyzed.Among 1080 identified tear proteins(FDR<1%),57 proteins and 15 proteins were found to be up-regulated and down-regulated,respectively,in patients with PVS after s TBI as compared to normal controls.Bioinformatics analysis revealed that differentially expressed proteins were mostly involved in wound response,inflammatory and immune response.We also found that peptidase and protease inhibitors may play important roles in this progress.Furthermore,we verified the levels of 7 differentially expressed proteins in tears from 50 patients with PVS after s TBI and 50 normal controls(including samples used in discovery phase)using ELISA.The results showed that combination of 7 proteins had a high discrimination ability for PVS after s TBI(AUC=0.999).Our work provided novel insights into the mechanisms of PVS after s TBI and identified potential tear protein markers for diagnosis and prognosis.