HEPSYS-IV PROTEOMICS PROFILING OF HUMAN ALF PLASMA REVEALS CLINICALLY-RELEVANT PROTEIN EXPRESSION PATTERNS

Leonard Nelson, Sarah Martin, Sophie M. Rogers, Thierry Le Bihan, Philipp Treskes, K. A. Lockman, Steven D Morley, Darren G N Craig, Peter Hayes, Kenneth Simpson, John Plevris

Research output: Contribution to conferencePosterpeer-review

Abstract

Acute liver failure (ALF) is a devastating syndrome occurring in previously healthy individuals; patients
develop coagulopathy, hepatic encephalopathy and multi-organ failure with liver transplantation being
the only life saving treatment. Molecular mechanisms underlying the pathophysiologic changes remain
poorly understood. In this study proteomic analysis was used to identify altered protein levels in ALF
human plasma.
Objectives: To develop a systems biology approach to study protein expression in human ALF plasma
vs normal subjects. This approach is aimed at further understanding the pathophysiology of ALF with
potential development of biomarkers and therapeutic targets.
Methods: 10μl Normal or ALF plasma-EDTA (n=3, 560μg protein) were reduced, alkylated, digested
and cleaned. 1.3 μg was analysed by liquid chromatography-coupled mass spectrometry (Agilent HPLC/
OrbitrapXL). Results were analysed using Progenesis LC-MS and MASCOT, and predicted functional
partners (PFPs) determined using STRING Database v9.0. STRING was used as a tool to help identify
potential protein interaction networks, for system-level understanding of pathophysiology in ALF.
Results: 22 of 148 identified proteins were significantly different in abundance in ALF vs Normal plasma
[defined as: peptide count >2; Fold change >2x; P value <0.05]. Upregulated in ALF we found the urea
cycle enzyme ASS1 (1900x; PFPs: NOS1, NOS3; putative neurotransmitters) and Catalase (300x; PFPs:
antioxidant enzymes SOD1 and SOD3, FOXO3, which triggers apoptosis in the absence of survival factors
following oxidative stress). Downregulated in ALF we found Transthyretin, which is involved in thyroxine
transport (200x; PFP: HNF4, transcription factor involved in hepatocyte differentiation), coagulation
factors, e.g. Thrombin (300x; PFP: Factors II, V, VIII, SERPINC1) and several proteins related to cell
adhesion, e.g. Complement system C-4 (1300x; PFP: ECM glycoprotein, Tenascin-XB, which has antiadhesive
effects) and Vitronectin (x15; PFP: Integrins alpha-5, alpha-V, FN1), involved in cell adhesion
via an RGD integrin binding sequence.
Conclusions: Proteomic profiling of normal vs ALF plasma demonstrates clinically relevant
pathophysiological changes in protein expression which are correlated with putative PFPs and cognate
protein interaction networks. These may point towards novel molecular mechanisms and new therapies
in the pathophysiology of ALF.
Original languageEnglish
Publication statusPublished - Feb 2013
EventlEASL Monothematic Conference: Systems Biology of the Liver: Systems Biology and Clinics Face-à-Face - Luxemburg, Luxembourg
Duration: 21 Feb 201323 Feb 2013

Conference

ConferencelEASL Monothematic Conference: Systems Biology of the Liver: Systems Biology and Clinics Face-à-Face
CountryLuxembourg
CityLuxemburg
Period21/02/1323/02/13

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