Proteoforms in Peripheral Blood Mononuclear Cells as Novel Rejection Biomarkers in Liver Transplant Recipients.
T K TobyMichael M I AbecassisK KimP M ThomasR T FellersR D LeDucN L KelleherJ DemetrisJ LevitskyPublished in: American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons (2017)
Biomarker profiles of acute rejection in liver transplant recipients could enhance the diagnosis and management of recipients. Our aim was to identify diagnostic proteoform signatures of acute rejection in circulating immune cells, using an emergent "top-down" proteomics methodology. We prepared differentially processed and cryopreserved cell lysates from 26 nonviral liver transplant recipients by molecular weight-based fractionation and analyzed them by mass spectrometry of whole proteins in three steps: (i) Nanocapillary liquid chromatography coupled with high-resolution tandem mass spectrometry; (ii) database searching to identify and characterize intact proteoforms; (iii) data processing through a hierarchical linear model matching the study design to quantify proteoform fold changes in patients with rejection versus normal liver function versus acute dysfunction without rejection. Differentially expressed proteoforms were seen in patients with rejection versus normal and nonspecific controls, most evidently in the cell preparations stored in traditional serum-rich media. Mapping analysis of these proteins back to genes through gene ontology and pathway analysis tools revealed multiple signaling pathways, including inflammation mediated by cytokines and chemokines. Larger studies are needed to validate these novel rejection signatures and test their predictive value for use in clinical management.
Keyphrases
- liquid chromatography
- mass spectrometry
- tandem mass spectrometry
- high resolution
- liver failure
- high performance liquid chromatography
- ultra high performance liquid chromatography
- genome wide
- gas chromatography
- single cell
- high resolution mass spectrometry
- respiratory failure
- simultaneous determination
- oxidative stress
- signaling pathway
- drug induced
- copy number
- cell therapy
- aortic dissection
- solid phase extraction
- emergency department
- gene expression
- electronic health record
- mesenchymal stem cells
- intensive care unit
- endoplasmic reticulum stress
- bone marrow
- hepatitis b virus
- high speed
- big data
- umbilical cord