Open AccessProtein profiling of human lung telocytes and microvascular endothelial cells using i TRAQ quantitative proteomics
Author(s) -
Zheng Yonghua,
Cretoiu Dragos,
Yan Guoquan,
Cretoiu Sanda Maria,
Popescu Laurentiu M.,
Fang Hao,
Wang Xiangdong
Publication year - 2014
Publication title -
journal of cellular and molecular medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.44
H-Index - 130
eISSN - 1582-4934
pISSN - 1582-1838
DOI - 10.1111/jcmm.12350
Subject(s) - microbiology and biotechnology , proteomics , von willebrand factor , cytoskeleton , biology , glycoprotein , intermediate filament , quantitative proteomics , cell , immunology , gene , biochemistry , platelet
Abstract Telocytes ( TC s) are described as a particular type of cells of the interstitial space ( www.telocytes.com ). Their main characteristics are the very long telopodes with alternating podoms and podomers. Recently, we performed a comparative proteomic analysis of human lung TC s with fibroblasts, demonstrating that TC s are clearly a distinct cell type. Therefore, the present study aims to reinforce this idea by comparing lung TC s with endothelial cells ( EC s), since TCs and ECs share immunopositivity for CD34. We applied isobaric tag for relative and absolute quantification ( iTRAQ ) combined with automated 2‐D nano‐ ESI LC ‐ MS / MS to analyse proteins extracted from TC s and EC s in primary cell cultures. In total, 1609 proteins were identified in cell cultures. 98 proteins (the 5th day), and 82 proteins (10th day) were confidently quantified (screened by two‐sample t ‐test, P < 0.05) as up‐ or down‐regulated (fold change >2). We found that in TC s there are 38 up‐regulated proteins at the 5th day and 26 up‐regulated proteins at the 10th day. Bioinformatics analysis using Panther revealed that the 38 proteins associated with TC s represented cellular functions such as intercellular communication ( via vesicle mediated transport) and structure morphogenesis, being mainly cytoskeletal proteins and oxidoreductases. In addition, we found 60 up‐regulated proteins in EC s e.g .: cell surface glycoprotein MUC 18 (15.54‐fold) and von W illebrand factor (5.74‐fold). The 26 up‐regulated proteins in TC s at 10th day, were also analysed and confirmed the same major cellular functions, while the 56 down‐regulated proteins confirmed again their specificity for EC s. In conclusion, we report here the first extensive comparison of proteins from TC s and EC s using a quantitative proteomics approach. Our data show that TC s are completely different from EC s. Protein expression profile showed that TC s play specific roles in intercellular communication and intercellular signalling. Moreover, they might inhibit the oxidative stress and cellular ageing and may have pro‐proliferative effects through the inhibition of apoptosis. The group of proteins identified in this study needs to be explored further for the role in pathogenesis of lung disease.