Comparativ Proteome Research On Liver Sinusoidal Capillarization

Liver sinusoidal endothelial cells comprise approximately50%of thenon-parenchymal hepatic cells. They separate hepatocytes from the passing blood andplay an important role in hepatic microcirculation. These cells lack a basementmembrane, form a fenestrated monolayer, express a variety of scavenger receptors,and control the exchange of substance between the blood and the liver parenchyma,constituting the most powerful scavenger system in the body. When liver is invadedby a variety of pathogens, LSECs loss fenestrations and form a underlying basementmembrane, which are the characteristics of continuous endothelial cells, this processcalled capillarization. It is caused by many factors, the process is complex, and existin the early stage of liver diseases. In order to make further exploration into themechanism of LSEC capillarization and to search for the candidates of diagnosticmarker and therapeutic target, we used NaAsO2to estabilish sinusoidal capillarizationC57BL/6J animal model, two-dimensional difference gel electrophoresis (2-DDIGE) was employed to conduct differential proteome analysis on LSECcapillarization animal model groups and control models.We use drinking water containing250μg/L NaAsO2to feed C57BL/6J mouse5weeks. The liver pathology features included liver sinusoidal capillarization and mildliver fibrosis. And then we used OptiprepTMand CD146microbeads to isolated liversinusoidal endothelial cell in control and As-exposed groups.2D-DIGE was used toseparate the proteins expressed in LSEC, and8reliable proteins were identified usingMALDI-TOF/TOF-MS, among which1protein was upregulated and7proteins weredownregulated in model groups. Thee differentially expressed proteins were validatedby Western blotting. Among these proteins, Anp32A is the G protein related factor asan S1P target, which involving in a number of cellular processes, includingproliferation, differentiation, caspase-dependent and caspase-independent apoptosis,tumor suppressor and so on. RhoGDI2is a Rho-GDPase dissociation inhibitor, whichregulates the GDP/GTP exchange reaction of the Rho proteins by inhibiting thedissociation of GDP from them, and the subsequent binding of GTP to them, and itsdown-regulation can activate NADPH oxidase subunit Rac1, leading to the activationof NADPH oxidase. S100a9is novel NF-κB target genes in HCC cells duringinflammation-associated liver carcinogenesis and increased co-expression of S100a8and S100a9supports malignant progression by activation of ROS-dependent signalingpathways and protection from cell death. Together, these results help clarify thepathogenesis of LSEC capillarization and identify potential targets for therapeuticinterventions.