title: Endogenous oxidative stress prevents telomerase-dependent immortalization of human endothelial cells.
abstract: BACKGROUND
  With aging, oxidative stress accelerates vascular endothelial cell (EC) telomere shortening-induced senescence, and may promote atherosclerosis in humans. Our aim was to investigate whether an antioxidant treatment combined with telomerase (hTERT) over-expression would prevent senescence of EC isolated from patients with severe atherosclerosis.
  
  
  METHODS
  Cells were isolated from internal mammary arteries (n=11 donors), cultured until senescence with or without N-acetylcystein (NAC) and infected, or not, with a lentivirus over-expressing hTERT.
  
  
  RESULTS
  Compared to control EC, hTERT-NAC cells had increased telomerase activity, longer telomeres and underwent more cell divisions. According to the donor, hTERT-NAC either delayed (n=5) or prevented (n=4) EC senescence, the latter leading to cell immortalization. Lack of cell immortalization by hTERT-NAC was accompanied by an absence of beneficial effect of NAC alone in paired EC. Accordingly, lack of EC immortalization by hTERT-NAC was associated with high endogenous susceptibility to oxidation. In EC where hTERT-NAC did not immortalize EC, p53, p21 and p16 expression increased with senescence, while oxidative-dependent DNA damage associated with senescence was not prevented.
  
  
  CONCLUSIONS
  Our data suggest that irreversible oxidative stress-dependent damages associated with cardiovascular risk factors are responsible for senescence of EC from atherosclerotic patients.
authors.affiliation: Department of Surgery, Research Center, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Voghel
authors.forename: Nathalie
authors.initials: N
authors.lastname: Thorin-Trescases
authors.forename: Aida M
authors.initials: AM
authors.lastname: Mamarbachi
authors.forename: Louis
authors.initials: L
authors.lastname: Villeneuve
authors.forename: Frédérick A
authors.initials: FA
authors.lastname: Mallette
authors.forename: Gerardo
authors.initials: G
authors.lastname: Ferbeyre
authors.forename: Nada
authors.initials: N
authors.lastname: Farhat
authors.forename: Louis P
authors.initials: LP
authors.lastname: Perrault
authors.forename: Michel
authors.initials: M
authors.lastname: Carrier
authors.forename: Eric
authors.initials: E
authors.lastname: Thorin
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000368:Aged; D050197:Atherosclerosis / Q000201:enzymology / Q000503:physiopathology*; D002478:Cells, Cultured; D016922:Cellular Senescence; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D004249:DNA Damage; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology*; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D012306:Risk; D019098:Telomerase / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016166:Free Radical Scavengers; D016159:Tumor Suppressor Protein p53; D019098:Telomerase; D000111:Acetylcysteine
references.citation: J Cell Sci. 2004 May 1;117(Pt 11):2417-26
references.pmid: 15126641
references.citation: Science. 1994 Dec 23;266(5193):2011-5
references.pmid: 7605428
references.citation: Am J Physiol Heart Circ Physiol. 2006 May;290(5):H1729-39
references.pmid: 16603702
references.citation: Arterioscler Thromb Vasc Biol. 2004 Jan;24(1):98-105
references.pmid: 14563650
references.citation: Circ Res. 2004 Apr 2;94(6):768-75
references.pmid: 14963003
references.citation: Science. 1997 Aug 8;277(5327):831-4
references.pmid: 9242615
references.citation: Arterioscler Thromb Vasc Biol. 2004 Mar;24(3):546-50
references.pmid: 14726417
references.citation: Am J Epidemiol. 2007 Jan 1;165(1):14-21
references.pmid: 17043079
references.citation: J Cell Sci. 2008 Apr 1;121(Pt 7):1046-53
references.pmid: 18334557
references.citation: Free Radic Biol Med. 2008 Feb 1;44(3):235-46
references.pmid: 18021748
references.citation: Exp Gerontol. 2005 Aug-Sep;40(8-9):634-42
references.pmid: 15970413
references.citation: J Biol Chem. 1999 Sep 10;274(37):26141-8
references.pmid: 10473565
references.citation: Free Radic Res. 2006 Dec;40(12):1277-83
references.pmid: 17090417
references.citation: Methods Mol Biol. 2007;371:179-89
references.pmid: 17634582
references.citation: Lancet. 2001 Aug 11;358(9280):472-3
references.pmid: 11513915
references.citation: Circ Res. 2000 Sep 29;87(7):540-2
references.pmid: 11009557
references.citation: Science. 2004 Mar 26;303(5666):2011-5
references.pmid: 14976264
references.citation: Exp Cell Res. 2000 Nov 1;260(2):357-64
references.pmid: 11035931
references.citation: DNA Repair (Amst). 2005 Nov 21;4(11):1306-13
references.pmid: 16084131
references.citation: Cell. 2008 Jun 13;133(6):958-61
references.pmid: 18555773
references.citation: Cancer Res. 1995 Sep 15;55(18):4047-52
references.pmid: 7664278
references.citation: Curr Biol. 1998 Feb 26;8(5):279-82
references.pmid: 9501072
references.citation: Circ Res. 2001 Oct 26;89(9):793-8
references.pmid: 11679409
references.citation: Science. 1998 Jan 16;279(5349):349-52
references.pmid: 9454332
references.citation: Aging Cell. 2003 Oct;2(5):235-43
references.pmid: 14570231
references.citation: Cell Physiol Biochem. 2007;20(1-4):45-54
references.pmid: 17595514
references.citation: J Histochem Cytochem. 2006 Aug;54(8):897-904
references.pmid: 16585386
references.citation: Cancer Res. 2006 Nov 15;66(22):10805-14
references.pmid: 17108117
references.citation: Nat Rev Mol Cell Biol. 2007 Sep;8(9):729-40
references.pmid: 17667954
references.citation: Mech Ageing Dev. 2008 May;129(5):261-70
references.pmid: 18302967
references.citation: Trends Biochem Sci. 2002 Jul;27(7):339-44
references.pmid: 12114022
references.citation: Carcinogenesis. 2001 Jul;22(7):999-1013
references.pmid: 11408342
references.citation: Arterioscler Thromb Vasc Biol. 2003 May 1;23(5):842-6
references.pmid: 12649083
references.citation: J Mol Cell Cardiol. 2007 Nov;43(5):571-9
references.pmid: 17916362
references.citation: Int J Biochem Cell Biol. 2005 May;37(5):961-76
references.pmid: 15743671
references.citation: Cell Cycle. 2007 Feb 1;6(3):371-6
references.pmid: 17297310
references.citation: FASEB J. 2009 Mar;23(3):783-94
references.pmid: 18948382
references.citation: Cell Mol Life Sci. 2003 Jan;60(1):6-20
references.pmid: 12613655
references.citation: Trends Biochem Sci. 2007 Dec;32(12):555-60
references.pmid: 17980602
references.citation: Aging Cell. 2009 Jun;8(3):311-23
references.pmid: 19627270
references.citation: Am J Physiol Regul Integr Comp Physiol. 2009 Feb;296(2):R374-82
references.pmid: 19036828
references.citation: Circ Res. 2008 Jul 3;103(1):34-42
references.pmid: 18519947
references.citation: J Biol Chem. 2002 Oct 11;277(41):38540-9
references.pmid: 12140282
references.citation: Proc Natl Acad Sci U S A. 1995 Sep 26;92(20):9363-7
references.pmid: 7568133
references.citation: J Biol Chem. 2004 Jan 16;279(3):2030-7
references.pmid: 14570874
references.citation: Biochem Biophys Res Commun. 2007 Oct 26;362(3):707-11
references.pmid: 17720141
references.citation: Mech Ageing Dev. 2007 Nov-Dec;128(11-12):662-71
references.pmid: 18022214
references.citation: Mech Ageing Dev. 2005 Jan;126(1):105-10
references.pmid: 15610768
references.citation: Am J Physiol Heart Circ Physiol. 2007 Jun;292(6):H2913-20
references.pmid: 17277030
references.citation: J Am Coll Cardiol. 2007 Apr 3;49(13):1459-64
references.pmid: 17397675
references.citation: Mech Ageing Dev. 2008 Jul-Aug;129(7-8):467-74
references.pmid: 18502472
references.citation: Can J Physiol Pharmacol. 2008 Nov;86(11):761-9
references.pmid: 19011671
references.citation: Mech Ageing Dev. 2001 Oct;122(15):1685-94
references.pmid: 11557273
references.citation: Exp Cell Res. 1995 Sep;220(1):194-200
references.pmid: 7664836
references.citation: Am J Respir Crit Care Med. 2008 Apr 15;177(8):861-70
references.pmid: 18174544
references.citation: Exp Cell Res. 2006 Aug 15;312(14):2641-6
references.pmid: 16893723
references.citation: FEBS Lett. 2008 May 28;582(12):1685-92
references.pmid: 18439424
references.citation: Mech Ageing Dev. 2005 Jan;126(1):111-7
references.pmid: 15610769
references.citation: Biochem J. 2007 May 15;404(1):1-13
references.pmid: 17447894
references.citation: Circulation. 2002 Apr 2;105(13):1541-4
references.pmid: 11927518
references.citation: J Mol Biol. 1992 Jun 20;225(4):951-60
references.pmid: 1613801
references.citation: Biogerontology. 2009 Dec;10(6):683-93
references.pmid: 19214769
references.citation: Ann N Y Acad Sci. 2004 Jun;1019:278-84
references.pmid: 15247029
references.citation: EMBO J. 2002 May 15;21(10):2383-96
references.pmid: 12006491
references.citation: Nature. 1990 May 31;345(6274):458-60
references.pmid: 2342578