| Popis: |
To study the DNA damage and recovery induced by hydrogen peroxide in normal aging and premature aging human cells.The immunofluorescent assay and comet assay were used to estimate basal DNA damage in normal aging BJ cells and premature aging Hutchinson-Gilford progeria syndrome (HGPS) cells, which were divided into three and two distinct population doubling (PD) number groups (BJ 14, 30, 45 and HGPS 8, 17) respectively. The DNA damage induced by hydrogen peroxide of these cell populations, as well as their repair activity, was also studied. Finally, the recovery capability before and after the xeroderma pigmentosum group A (XPA) knocked down in these groups was measured.Our results indicated that the normal BJ cells of older PD number showed higher basal levels of DNA damage and were more sensitive to the effects of the DNA-damaging agents than the adult one, who, in turn, was more sensitive than the younger ones. The basal damage level of HGPS cells was same or higher than the older BJ cells. HGPS cells also had the same consistent damage change as BJ cells after treatment. The decline of the repair efficiency with age to the DNA damage induced by the agent was also observed.The DNA repair of HGPS is repressed by dysfunction of XPA. |
