Protein Biomarkers and Neuroproteomics Characterization of Microvesicles/Exosomes from Human Cerebrospinal Fluid Following Traumatic Brain Injury

This study sought to examine if CSF samples from severe TBI patients contain MV/E with unique protein contents. First, nanoparticle tracking analysis determined MV/E from TBI have a mode of 74 –98 nm in diameter, while control CSF MV/E have a mode of 99–104 nm. Also, there are more MV/E were isolated from TBI CSF (27.8–33.6 × 108/mL) than from control CSF (13.1 –18.5 × 108/mL). Transmission electron microscopy (TEM) visualization also confirmed characteristic MV/E morphology. Using targeted immunoblotting approach, we observed the presence of several known TBI biomarkers such as αII-spectrin breakdown products (BDPs), GFAP, and its BDPs and UCH-L1 in higher concentrations in MV/E from TBI CSF than their counterparts from control CSF. Furthermore, we found presynaptic terminal protein synaptophysin and known exosome marker Alix enriched in MV/E from human TBI CSF. In parall el, we conducted nRPLC-tandem mass spectrometry-based proteomic analysis of two control and two TBI CSF samples. Ninety-one proteins were identified with high confidence in MV/E from control CSF, whereas 466 proteins were identified in the counterpart from TBI CSF. MV/E isolated from human CSF conta in cytoskeletal proteins, neurite-outgrowth related proteins, and synaptic proteins, extracellular matrix proteins, and complement protein C1q subcomponent subunit B. Taken together, following severe TBI, the injured human brain released increased number of extracellular microvesicles/exosom...
Source: Molecular Neurobiology - Category: Neurology Source Type: research