Overexpression of apolipoprotein J in human fibroblasts protects against cytotoxicity and premature senescence induced by ethanol and tert-butylhydroperoxide.
Human diploid fibroblasts (HDFs) exposed to subcytotoxic stresses under H2O2, tert-butylhydroperoxide (t-BHP), and ethanol (EtOH) undergo stress-induced premature senescence (SIPS) characterized by many biomarkers of HDFs replicative senescence. Among these biomarkers are a growth arrest, an increase in the senescence-associated beta-galactosidase activity, a senescent morphology, an overexpression of p21waf-1 and the subsequent inability to phosphorylate pRb, the presence of the common 4977-bp mitochondrial deletion, and an increase in the steady-state level of several senescence-associated genes such as apolipoprotein J (apo J). Apo J has been described as a survival gene against cytotoxic stress. In order to study whether apo J would be protective against cytotoxicity SIPS and replicative senescence in human fibroblasts, a full-length complementary deoxyribonucleic acid of apo J was transfected into WI-38 HDFs and SV40-transformed WI-38 HDFs. The overexpression of apo J resulted in an increased cell survival after t-BHP and EtOH stresses at cytotoxic concentrations. In addition, when WI-38 HDFs were exposed to 5 subcytotoxic stresses with EtOH or t-BHP, in conditions that were previously shown to induce SIPS, a lower induction of 2 biomarkers of SIPS was observed in HDFs overexpressing apo J. No effect of apo J overexpression was observed on the proliferative life span of HDFs, even if apo J overexpression triggered osteonectin (SPARC) overexpression, which was shown to decrease the mitogenic potential of platelet-derived growth factor but not of other common growth-inducing conditions. Apo J senescence-related overexpression is proposed to have antiapoptotic rather than antiproliferative effects.
Dumont
Patrick
P
Unit of Cellular Biochemistry and Biology, Department of Biology, The University of Namur (FUNDP), Belgium.
Chainiaux
Florence
F
Eliaers
François
F
Petropoulou
Chariklia
C
Remacle
José
J
Koch-Brandt
Claudia
C
Gonos
Efstathios S
ES
Toussaint
Olivier
O
D002461:Cell Line, Transformed; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects*; D002492:Central Nervous System Depressants / Q000633:toxicity*; D051152:Clusterin; D000431:Ethanol / Q000633:toxicity*; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D005353:Fibronectins / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D006023:Glycoproteins / Q000235:genetics*; D006801:Humans; D008934:Mitogens / Q000494:pharmacology; D018832:Molecular Chaperones / Q000235:genetics*; D015676:Osteonectin / Q000235:genetics; D018384:Oxidative Stress / Q000187:drug effects; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins / Q000235:genetics; D013539:Simian virus 40 / Q000235:genetics; D013936:Thymidine / Q000493:pharmacokinetics; D014316:Tritium; D001616:beta-Galactosidase / Q000235:genetics; D020122:tert-Butylhydroperoxide / Q000633:toxicity*
C495242:CLU protein, human; D002492:Central Nervous System Depressants; D051152:Clusterin; D005353:Fibronectins; D006023:Glycoproteins; D008934:Mitogens; D018832:Molecular Chaperones; D015676:Osteonectin; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014316:Tritium; D000431:Ethanol; D020122:tert-Butylhydroperoxide; D001616:beta-Galactosidase; D013936:Thymidine