title: Vulnerability to oxidative stress and different patterns of senescence in human peritoneal mesothelial cell strains.
abstract: Both the ascites fluid-derived mesothelial cell line LP-9 and primary cultures of human omentum-derived mesothelial cells (HOMCs) are commonly used in experimental studies. However, they seem to have a different replicative potential in vitro. In the present study, we have attempted to determine the causes of this discrepancy. HOMCs were found to divide fewer times and enter senescence earlier than LP-9 cells. This effect was coupled with earlier increases in the expression of senescence-associated-beta-galactosidase and cell cycle inhibitors p16INK4a and p21WAF1. Moreover, almost 3 times as many early-passage HOMCs as LP-9 cells bore senescence-associated DNA damage foci. In sharp contrast to LP-9 cells, the foci present in HOMCs localized predominantly outside the telomeres, and the HOMC telomere length did not significantly shorten during senescence. Compared with LP-9 cells, HOMCs were found to enter senescence with significantly lower levels of lipofuscin and damaged DNA, and markedly decreased glutathione contents. In addition, early-passage HOMCs generated significantly more reactive oxygen species either spontaneously or in response to exogenous oxidants. These results indicate that compared with LP-9 cells, HOMCs undergo stress-induced telomere-independent premature senescence, which may result from increased vulnerability to oxidative DNA injury.
authors.affiliation: Department of Pathophysiology, Poznan Univ. of Medical Sciences, Swiecickiego 6, 60-781 Poznan, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Ksiazek
authors.forename: Justyna
authors.initials: J
authors.lastname: Mikula-Pietrasik
authors.forename: Sharon
authors.initials: S
authors.lastname: Olijslagers
authors.forename: Achim
authors.initials: A
authors.lastname: Jörres
authors.forename: Thomas
authors.initials: T
authors.lastname: von Zglinicki
authors.forename: Janusz
authors.initials: J
authors.lastname: Witowski
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000328:Adult; D000975:Antioxidants / Q000378:metabolism; D002460:Cell Line; D049109:Cell Proliferation; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000235:genetics; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism*; D005260:Female; D006657:Histones / Q000378:metabolism; D006801:Humans; D008062:Lipofuscin / Q000378:metabolism; D009852:Omentum / Q000378:metabolism; D018384:Oxidative Stress; D010537:Peritoneum / Q000201:enzymology / Q000378:metabolism*; D010641:Phenotype; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D016615:Telomere / Q000378:metabolism; D013997:Time Factors; D055815:Young Adult; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D000975:Antioxidants; C493956:CDKN1A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21; C468783:H2AX protein, human; D006657:Histones; D008062:Lipofuscin; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D000080242:8-Hydroxy-2'-Deoxyguanosine; D001616:beta-Galactosidase; D003849:Deoxyguanosine