title: Clusterin/Apolipoprotein J up-regulation after zinc exposure, replicative senescence or differentiation of human haematopoietic cells.
abstract: Clusterin/Apolipoprotein J (CLU) is a cellular senescence biomarker implicated in several physiological processes. In this work we have investigated CLU expression and function in human haematopoietic cells. We found that early passage human T cell clones (TCC) express minimal endogenous amounts of CLU, which are significantly elevated in late passage cells. Moreover, exposure of TCC to increased levels of the essential micronutrient zinc in culture resulted in intense induction of CLU. Because haematopoietic cells cease proliferation following induction of terminal differentiation, we also studied the expression profile of CLU in the leukemic progenitor cell lines K562 and HL-60. We found that, like TCC, both cell lines express minimal endogenous levels of CLU in their actively proliferating state. However, when induced to differentiate into their distinct cell types, CLU was found to be up-regulated specifically in those cells expressing the main differentiation markers. Enforced stable over-expression of CLU in K562 cells inhibited the expression of the CD14 differentiation marker and blocked differentiation to either monocytes/megacaryoblasts or to erythrocytes. Overall, our results suggest that CLU is actively involved in both replicative senescence and terminal differentiation in different types of human haematopoietic cells.
authors.affiliation: Laboratory of Molecular & Cellular Ageing, Institute of Biological Research & Biotechnology, National Hellenic Research Foundation, 48 Vas. Constantinou Ave., Athens, 11635, Greece.
authors.forename: Ioannis P
authors.initials: IP
authors.lastname: Trougakos
authors.forename: Graham
authors.initials: G
authors.lastname: Pawelec
authors.forename: Christos
authors.initials: C
authors.lastname: Tzavelas
authors.forename: Triantaphillia
authors.initials: T
authors.lastname: Ntouroupi
authors.forename: Efstathios S
authors.initials: ES
authors.lastname: Gonos
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation; D016922:Cellular Senescence / Q000187:drug effects; D051152:Clusterin / Q000235:genetics / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000378:metabolism; D018922:HL-60 Cells; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D020014:K562 Cells; D018950:Lipopolysaccharide Receptors / Q000378:metabolism; D018977:Micronutrients / Q000378:metabolism* / Q000494:pharmacology; D009000:Monocytes / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors; D014162:Transfection; D015854:Up-Regulation; D015032:Zinc / Q000378:metabolism* / Q000494:pharmacology
chemical_list: C495242:CLU protein, human; D051152:Clusterin; D018950:Lipopolysaccharide Receptors; D018977:Micronutrients; D015032:Zinc