Résumé
AIM: To explore the relationship between the expression of caspase-2 and caspase-3 and the apoptosis in retinal ischemia/reperfusion (I/R) injury of rats, as well as the therapeutic effects of brain derived neurotrophic factor (BDNF)on the ischemic and reperfused retina.METHODS: This experiment was conducted at the laboratory of Affiliated Hospital of Qingdao University Medical College from February 2007 to July 2007. The models of retinal ischemia/reperfusion injury were made by transiently elevating intraocular pressure. A total of 28 rats were divided into Normal and Operative Groups. Operative group was divided into six subgroups. In each subgroup there were four rats. The left eyes of rats were used for I/R and the right eyes were used for intravitreal injection of brain-derived neurotrophic factor (BDNF) as treatment group. After reperfusion we divided our subgroups according to the reperfusion time as 1, 6, 12, 24, 48, 72 hours. The retinal ganglion cell number was counted by using optic microscope(BX-51,Olympus). Apoptosis was assessed by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labelling (TUNEL) method, and the expression of caspase-2,caspase-3 was studied by enzyme linked immunosorbent assay (ELISA) and strept avidin-biotin complex (SABC)immunohistochemistry.RESULTS: No positive apoptotic cells were observed in the normal rats' retinae, but there were a significant number of positive apoptosis cells in 6-24 hours after transient ischemia followed by a decrease at 48 hours. The number of apoptotic cells reached a maximum at 24 hours after ischemia .The expression of caspase-2 gradually increased as early as at 6 hours, reached a peak at 24 hours, then decreased between 48 and 72 hours. Similarly, caspase-3 has the same rule with caspsae-2 in the time courses of expression in retinal tissues.BDNF administered before reperfusion inhibited the expression of apoptosis and ameliorated the retinal tissue damage. It also decreased caspase-2 and caspase-3 expression in ischemic/reperfused retina.CONCLUSION: Retinal ischemia-reperfusion can induce apoptosis of cells in the retina. BDNF rescues retinal ganglion cells (RGCs) from retinal ischemia/reperfusion injury through down-regulation of cell apoptosis and caspase-2 and caspase-3 expression. BDNF have a neuroprotective effect on retina.
Résumé
Objective To investigate the effect of caspase-2 and caspase-3 in cisplatin-induced apoptosis in cisplatin-resistant and-sensitive human ovarian cancer cell lines, A2780/DDP and A2780. Methods A2780 and A2780/DDP cells were incubated with various doses(0,5,10,20,40?M) of cisplatin for 24,48 and 72 hours, respectively. The protein expressions of caspase-2 and caspase-3 in the ovarian cancer cell lines were detected by immunohistochemical technology. The apoptotic rate of the ovarian cancer cell lines was determined by TUNEL. Results After cisplatin treated, apoptotic rates of both 2780 and A2780/DDP cell lines increased in time-and dose-dependent manners (P
Résumé
Human caspase-2, Ich-1 (Ice and Ced-3 homolog), has two different forms of mRNA species derived from alternative splicing, which encodes Ich-1 and Ich-1s. Ich-1v which induces apoptosis is antagonist of Ich-1s which suppresses Rat-1 cell death by serum deprivation. To investigate functions of Ich-1 and Ich-1s in T celi apoptosis, the fusion DNA constructs were made with the ecto and transmembrane of CDB and Ich-lv or Ich-1s and CDS-Ich-1 or CD8-Ich-1s chimeric protein was transiently expressed on Jurkat T cells. Tyrosine phosphorylation of intracellular proteins was induced in these transfectans when activated shortly by anti-CDB Ab. CDB-Ich-li transfectant in serum-rich condition and CDB-Ich-ls transfectant in serum-deprived condition underwent apoptosis when treated with anti-CDS Ab or incubated with NIH3T3 cells expressing stably Fas-L on their surface. We also made six antisense DNA constructs which could specifically inhibit the expression of Ich-1v, Ich- 1s, and then they were transiently transfected into Jurkat T cell. The overexpression of both of the antisese- Ich-1 against N-terminal 42 bp and against C-terminal 366 bp inhibited apoptosis through Fas signalling. But, when three different forms of antisense-Ich-1s were overexpressed in their transfectants, antisense-DNA against N-terminal 197 bp increased knd the one against C-terminal 66 bp inhibited apoptosis, instead the full size of antisense-DNA did not give any effects on apoptosis through Fas pathway.