Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.99.3 (PRE)
 1,923 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

UVB-induced DNA damage is a crucial event in UVB-mediated apoptosis. On the other hand, UVB directly activates death receptors on the cell surface including CD95, implying that UVB-induced apoptosis can be initiated at the cell membrane through death receptor clustering. This study was performed to measure the relative contribution of nuclear and membrane effects in UVB-induced apoptosis of the human epithelial cell line HeLa. UVB-mediated DNA damage can be reduced by treating cells with liposomes containing the repair enzyme photolyase followed by exposure to photoreactivating light. Addition of photolyase followed by photoreactivation after UVB reduced the apoptosis rate significantly, whereas empty liposomes had no effect. Likewise, photoreactivating treatment did not affect apoptosis induced by the ligand of CD95, CD95L. UVB exposure at 4 degrees C, which prevents CD95 clustering, also reduced the apoptosis rate, but to a lesser extent. When cells were exposed to UVB at 4 degrees C and treated with photolyase plus photoreactivating light, UVB-induced apoptosis was almost completely prevented. Inhibition of caspase-3, a downstream protease in the CD95 signaling pathway, blocked both CD95L and UVB-induced apoptosis, whereas blockage of caspase-8, the most proximal caspase, inhibited CD95L-mediated apoptosis completely, but UVB-induced apoptosis only partially. Although according to these data nuclear effects seem to be slightly more effective in mediating UVB-induced apoptosis than membrane events, both are necessary for the complete apoptotic response. Thus, this study shows that nuclear and membrane effects are not mutually exclusive and that both components contribute independently to a complete response to UVB.
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PMID:Nuclear and cell membrane effects contribute independently to the induction of apoptosis in human cells exposed to UVB radiation. 1039 32

This study examines the effects of 6-day intensive training on lymphocyte counts and their expression of CD95. Eight healthy Kendo athletes underwent 6-day Kendo training of about 310 min each day. Blood samples were collected at 2 weeks before (PRE), the first day (Day 1), third day (Day 3), fifth day (Day 5), and 1 week after the training period (POST) to determine lymphocyte counts and CD95 expression on CD95 lymphocytes (CD4(+), CD8(+)) using flow cytometry. The total lymphocyte counts were significantly lower at Day 3 than at PRE. The CD8(+) cell counts were significantly lower at Day 3 than at PRE. The percentage of CD95(+) lymphocytes was significantly higher at Day 1 and Day 3 than at PRE. The percentage of CD8(+)CD95(+) cells did not change significantly. The total lymphocyte counts decreased and a concomitant increase of CD95(+) lymphocyte was observed, whereas the decrease in CD8(+) cell counts was not associated with the increase in CD8(+)CD95(+) cells. Therefore, short-term high-intensity exercise induced a decrease in the T lymphocyte counts without increasing in CD95(+) expression.
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PMID:Effect of 6-day intense Kendo training on lymphocyte counts and its expression of CD95. 1956 65