Comprehensive Characterization of Nanosized Extracellular Vesicles from Central and Peripheral Organs: Implications for Preclinical and Clinical Applications

Extracellular
vesicles (EVs) are nanosized vesicles that have been
garnering a lot of attention for their valuable role as potential
diagnostic markers and therapeutic vehicles for a plethora of pathologies.
While EV markers from biofluids such as plasma, serum, urine, cerebrospinal
fluid, and in vitro cell culture-based platforms
have been extensively studied, a significant knowledge gap that remains
is the characterization of specific organ-derived EVs (ODE). Here,
we present a standardized protocol for isolation and characterization
of purified EVs isolated from brain, heart, lung, kidney, and liver
from rat and postmortem human tissue. Next, using quantitative mass
spectrometry-based proteomics, we characterized the respective tissue
EV proteomes that identified synaptophysin, caveolin-3, solute carrier
family 22 member 2, surfactant protein B, and fatty acid-binding protein
1 as potential markers for the brain, heart, kidney, lung, and liver
EV, respectively. These respective tissue-specific markers were further
validated using both immunoblotting and a nanoplasmonic platform single
EV imaging analysis in the two species. To summarize, our study for
the first time using traditional biochemical and high-precision technology
platforms provides a valuable proof-of-concept approach in defining
specific ODE markers, which could further be developed as potential
therapeutic candidates for respective end organ-associated pathologies.