National Institute for Infectious Diseases L. Spallanzani, IRCCS, via Portuense 292, 00149 Rome, Italy.
Istituto Pasteur-Fondazione Cenci Bolognetti, Department of Cellular Biotechnologies and Haematology, Sapienza University of Rome, Via Regina Elena 324, 00161 Rome, Italy.
Proteome Sci. 2014 Mar 15;12(1):15. doi: 10.1186/1477-5956-12-15.
Despite extensive research on hepatic cells precursors and their differentiated states, much remains to be learned about the mechanism underlying the self-renewal and differentiation.
We apply the SILAC (stable isotope labeling by amino acids in cell culture) approach to quantitatively compare the membrane proteome of the resident liver stem cells (RLSCs) and their progeny spontaneously differentiated into epithelial/hepatocyte (RLSCdH). By means of nanoLC-MALDI-TOF/TOF approach, we identified and quantified 248 membrane proteins and 57 of them were found modulated during hepatocyte differentiation. Functional clustering of differentially expressed proteins by Ingenuity Pathway Analysis revealed that the most of membrane proteins found to be modulated are involved in cell-to-cell signaling/interaction pathways. Moreover, the upstream prediction analysis of proteins involved in cell-to-cell signaling and interaction unveiled that the activation of the mesenchymal to epithelial transition (MET), by the repression of TGFB1/Slug signaling, may be causal to hepatocyte differentiation.
Taken together, this study increases the understanding of the underlying mechanisms modulating the complex biological processes of hepatic stem cell proliferation and differentiation.
尽管已经对肝前体细胞及其分化状态进行了广泛的研究，但对于自我更新和分化的机制仍有许多需要了解。
我们应用 SILAC（细胞培养中氨基酸的稳定同位素标记）方法来定量比较驻留肝干细胞（RLSCs）及其自发分化为上皮/肝细胞（RLSCdH）的后代的膜蛋白质组。通过纳米 LC-MALDI-TOF/TOF 方法，我们鉴定和定量了 248 种膜蛋白，其中 57 种在肝细胞分化过程中被发现被调节。通过 IPA（Ingenuity Pathway Analysis）对差异表达蛋白进行功能聚类分析表明，大多数被发现被调节的膜蛋白参与细胞间信号转导/相互作用途径。此外，对细胞间信号转导和相互作用相关蛋白的上游预测分析表明，通过抑制 TGFB1/Slug 信号转导来激活间充质到上皮的转变（MET）可能是肝细胞分化的原因。
综上所述，这项研究增加了对调节肝干细胞增殖和分化这一复杂生物学过程的潜在机制的理解。
