Recent advances in protein profiling of tissues and tissue fluids

Abstract

Creating protein profiles of tissues and tissue fluids, which contain secreted proteins and peptides released from various cells, is critical for biomarker discovery as well as drug and vaccine target selection. It is extremely difficult to obtain pure samples from tissues or tissue fluids, however, and identification of complex protein mixtures is still a challenge for mass spectrometry analysis. Here, we summarize recent advances in techniques for extracting proteins from tissues for mass spectrometry profiling and imaging. We also introduce a novel technique using a capillary ultrafiltration (CUF) probe to enable in vivo collection of proteins from the tissue microenvironment. The CUF probe technique is compared with existing sampling techniques, including perfusion, saline wash, fine-needle aspiration and microdialysis. In this review, we also highlight quantitative mass spectrometric proteomic approaches with, and without, stable-isotope labels. Advances in quantitative proteomics will significantly improve protein profiling of tissue and tissue fluid samples collected by CUF probes.

Keywords::

• fluids
• mass spectrometry
• profiling
• protein
• tissue imaging
• ultrafiltration sampling

Acknowledgements

This work was supported by National Institutes of Health Grants: R01-AI067395–01, R21-R022754–01 and R21-I58002–01. We thank R Dorschner and YR Chen for editorial assistance.

Financial disclosure

The authors have no relevant financial interests, including employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties related to this manuscript.