Screening for differentially expressed proteins in patients with liver cirrhosis complicated by portal vein thrombosis

Objective To investigate the differentially expressed serum proteins in patients with liver cirrhosis complicated by portal vein thrombosis ( PVT) . Methods Serum samples were collected from 45 patients with liver cirrhosis who were hospitalized in Infectious Disease Center, The First Affiliated Hospital of Xinjiang Medical University, from November 2015 to November 2016, and among these patients, 22 had PVT and 23 had no PVT. Isobaric tags for relative and absolute quantitation ( i TRAQ) combined with chromatography and mass spectrometry were used to screen out the differentially expressed serum proteins, and a bioinformatics analysis was performed for the differentially expressed proteins. The Mann-Whitney U test was used for comparison of non-normally distributed continuous data between groups, and the chi-square test was used for comparison of categorical data between groups. The Fisher's exact test was used to compare the distribution of GO terms or KEGG pathways in the target protein set or total protein set, in order to evaluate the significance level of protein enrichment of a GO term or KEGG pathway. Results A total of 800 proteins were screened out, among which 86 were differentially expressed, including 32 upregulated proteins ( ratio ≥1. 2, P < 0. 05) and 54 downregulated proteins ( ratio ≤0. 83, P < 0. 05) . Among these proteins, 14 were associated with cellular component, 22 were involved in biochemical processes, and 10 were associated with molecular function. The KEGG analysis showed that there were significant differences in 18 proteins in 5 metabolic and signaling pathways between the liver cirrhosis-PVT group and liver cirrhosis group. These 5 metabolic and signaling pathways were associated with fat digestion and absorption, platelet activation, metabolism of glyoxylic acid and dicarboxylic acid, osteoclast differentiation, and axon guidance. Conclusion i TRAQ combined with chromatography and mass spectrometry can effectively screen out the differentially expressed serum proteins, among which GP5, FGA, and FGG may be potential biological markers for PVT in patients with liver cirrhosis and are worthy of further research.