title: Aminoguanidine delays the replicative senescence of human diploid fibroblasts.
abstract: BACKGROUND
  The accumulation of free radicals and advanced glycation end products (AGEs) in cell plays a very important role in replicative senescence. Aminoguanidine (AG) has potential antioxidant effects and decreases AGE levels. This study aimed to investigate its effect on replicative senescence in vitro.
  
  
  METHODS
  The effects of aminoguanidine on morphology, replicative lifespan, cell growth and proliferation, AGEs, DNA damage, DNA repair ability and telomere length were observed in human fetal lung diploid fibroblasts (2BS).
  
  
  RESULTS
  Aminoguanidine maintained the non-senescent phenotype of 2BS cells even at late population doubling (PD) and increased cumulative population doublings by at least 17 - 21 PDs. Aminoguanidine also improved the potentials of growth and proliferation of 2BS cells as detected by the MTT assay. The AGE levels of late PD cells grown from early PD in DMEM containing aminiguanidine decreased significantly compared with those of late PD control cells and were similar to those of young control cells. In addition, the cells pretreated with aminoguanidine had a significant reduction in DNA strand breaks when they were exposed to 200 micromol/L H(2)O(2) for 5 minutes which indicated that the compound had a strong potential to protect genomic DNA against oxidative stress. And most of the cells exposed to 100 micromol/L H(2)O(2) had much shorter comet tails and smaller tail areas after incubation with aminoguanidine-supplemented DMEM, which indicated that the compound strongly improved the DNA repair abilities of 2BS cells. Moreover, PD55 cells grown from PD28 in 2 mmol/L or 4 mmol/L aminoguanidine retain telomere lengths of 7.94 kb or 8.12 kb, which was 0.83 kb or 1.11 kb longer than that of the control cells.
  
  
  CONCLUSIONS
  Aminoguanidine delays replicative senescence of 2BS cells and the senescence-delaying effect of aminoguanidine appear to be due to its many biological properties including its potential for proliferation improvement, its inhibitory effect of AGE formation, antioxidant effect, improvement of DNA repair ability and the slowdown of telomere shortening.
authors: Department of Medical Laboratory, Xuanwu Hospital, Capital Medical University, Beijing 100053, China. peichangwang@yahoo.com
authors: Pei-chang
authors: PC
authors: Wang
authors: Jian
authors: J
authors: Zhang
authors: Zong-yu
authors: ZY
authors: Zhang
authors: Tan-jun
authors: TJ
authors: Tong
mesh_terms: D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects*; D004249:DNA Damage; D004260:DNA Repair; D004171:Diploidy; D004305:Dose-Response Relationship, Drug; D005260:Female; D005347:Fibroblasts / Q000187:drug effects; D017127:Glycation End Products, Advanced / Q000032:analysis; D006146:Guanidines / Q000494:pharmacology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D016615:Telomere
chemical_list: D017127:Glycation End Products, Advanced; D006146:Guanidines; D006861:Hydrogen Peroxide; C004479:pimagedine