title: Liver Sinusoidal Endothelial Cells Escape Senescence by Loss of p19ARF.
abstract: Liver sinusoidal endothelial cells (LSECs) represent a highly differentiated cell type that lines hepatic sinusoids. LSECs form a discontinuous endothelium due to fenestrations under physiological conditions, which are reduced upon chronic liver injury. Cultivation of rodent LSECs associates with a rapid onset of stress-induced senescence a few days post isolation, which limits genetic and biochemical studies ex vivo. Here we show the establishment of LSECs isolated from p19ARF-/- mice which undergo more than 50 cell doublings in the absence of senescence. Isolated p19ARF-/- LSECs display a cobblestone-like morphology and show the ability of tube formation. Analysis of DNA content revealed a stable diploid phenotype after long-term passaging without a gain of aneuploidy. Notably, p19ARF-/- LSECs express the endothelial markers CD31, vascular endothelial growth factor receptor (VEGFR)-2, VE-cadherin, von Willebrand factor, stabilin-2 and CD146 suggesting that these cells harbor and maintain an endothelial phenotype. In line, treatment with small molecule inhibitors against VEGFR-2 caused cell death, demonstrating the sustained ability of p19ARF-/- LSECs to respond to anti-angiogenic therapeutics. From these data we conclude that loss of p19ARF overcomes senescence of LSECs, allowing immortalization of cells without losing endothelial characteristics. Thus, p19ARF-/- LSECs provide a novel cellular model to study endothelial cell biology.
authors.affiliation: Department of Medicine I, Division: Institute of Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria.
authors.forename: Petra
authors.initials: P
authors.lastname: Koudelkova
authors.affiliation: Department of Medicine I, Division: Institute of Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Weber
authors.affiliation: Department of Medicine I, Division: Institute of Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Mikulits
mesh_terms: D000818:Animals; D000943:Antigens, Differentiation / Q000096:biosynthesis* / Q000235:genetics; D002460:Cell Line; D016922:Cellular Senescence / Q000235:genetics*; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics* / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout
chemical_list: D000943:Antigens, Differentiation; C417743:Cdkn2a protein, mouse; D019941:Cyclin-Dependent Kinase Inhibitor p16