The Relation Between Apoptosis And Telomere Lengths Changes In HUVEC And RGC

Objectives: To study the relation between telomere lengths changes and cell senescence, and the relation between telomere lengths changes and apoptosis , the mean tellomere length changes of human umbillicum vascular endothelial cells(HUVEC) with various population doubling times were measured. And to explore the possible existed relation between their telomere length changes and apoptosis , the mean telomere length changes in normal and apoptotic retinal ganglion cells (RGC) were also measured. Methods: With Fenton reaction apoptosis of HUVEC and RGC by free hydroxial radical were induced. With HE staining, DNA gel electrophoresis and Hoechest 33258 fluorescene staining, apoptosis were observed. With southern blot the mean telomere length changes of apoptotic or normal HUVEC or RGC were measured . By culturing HUVEC to simulate cell duplicating senescence , the status of duplicatedcell senescence were reflected by various mean population doubling time such as 1 and 20 , and the mean telomere length changes in HUVEC with various population doubling times also measured. In HUVEC the concentration of FeSO₄/ H₂O₂:0.2/0.0001(mmol/l:mmol/l)and the concentration of 0.2/0.005 as apoptosis 1 group and apoptosis 2 group respectively were compared with nomal contral group . With the same in RGC ,the concentration of 0.2/0.005 and 0.2/0.0001 also as the apoptosis group were compared with normal contral . 3. Results:。 (1) the mean telomere length (MTL)In normal HUVECs with 1 population doubling time and 20 time is:5.43±0.45kb and 4.57±0.21kb respectively . The MTL in apoptosis 1 group of HUVEC with 1 population doubling time and 20 time : 4.66±0.05kb and 3.40±0.46kb respectively, and in apoptosis 2 group of HUVEC with 1 population doubling time and 20 time the MTL: 3.67±0.05kb and 2.90±0.20kb . Significant differences statisticly exist in HUVEC mean telomere length between normal and apoptosis 1 group or 2 group , p<0.005. There are significant differences in HUUVEC mean telomere length between 1 population doubling time and 20 population doubling time , p<0.005。(2)In normal RGC , the mean telomere length (MTL) is: 8.20±0.33kb. In apoptotic RGC groups , the MTL is : 6.06±0.72kb and 6.44±0.48kb respectively . There is alsosignificant difference in HUVEC mean telomere lengths between normal and apoptotic group , p<0.005。Conclusions:In HUVEC there is some relation between MTL and senescence .The changes of the telomere length play some role in apoptosis .There are some variation in telomeres among all Retinal Ganglion Cells , their telomere length changes may take part in RGC apoptosis procedure .