Proteomic Analysis of Dysfunctional Liver Sinusoidal Endothelial Cells Reveals Substantial Differences in Most Common...

Molecular markers of dedifferentiation of dysfunctional liver sinusoidal endothelial cells (LSEC) have not been fully elucidated. We aimed at deciphering the molecular profile of dysfunctional LSEC in different pathological scenarios. Flow cytometry was used to sort CD11b^-/CD32b⁺ and CD11b^-/CD32b^- LSEC from three rat models of liver disease (bile duct ligation-BDL; inhaled carbon tetrachloride-CCl4; and high fat glucose/fructose diet-HFGFD). A full proteomic profile was performed applying nano-scale liquid chromatography tandem mass spectrometry (nLC-MS) and analyzed with PEAKS software. The percentage of CD32b^- LSEC varied across groups, suggesting different capillarization processes. Both CD32⁺ and CD32b^- LSEC from models are different from control LSEC, but differently expressed proteins in CD32b^- LSEC are significantly higher. Heatmaps evidenced specific protein expression patterns for each model. Analysis of biological significance comparing dysfunctional CD32b^- LSEC with specialized CD32b⁺ LSEC from controls showed central similarities represented by 45 common down-regulated proteins involved in the suppression of the endocytic machinery and 63 common up-regulated proteins associated with the actin-dependent cytoskeleton reorganization. In summary; substantial differences but also similarities in dysfunctional LSEC from the three most common models of liver disease were found, supporting the idea that LSEC may harbor different protein expression profiles according to the etiology or disease stage.