Adaptive changes in NAD+ metabolism in ultraviolet light-irradiated murine lymphoma cells |
| |
Authors: | Hanna E Kleczkowska Irena Szumiel Felix R Althaus |
| |
Institution: | (1) Institute of Nuclear Chemistry and Technology, PL-03 195 Warsaw, Poland;(2) Institute of Pharmacology and Biochemistry, University of Zürich-Tierspital, CH-8057 Zürich, Switzerland |
| |
Abstract: | We have determined the ability of UV254nm-irradiated murine lymphoma cells to adapt their NAD+ metabolism to the increased NAD+ consumption for the poly ADP-ribosylation of chromatin proteins. Two murine lymphoma sublines with differential UV-sensitivity
and poly(ADP-ribose) turnover were used as a model system. The first subline, designated LY-R is UV254nm-sensitive and tumorigenic in DBA/2 mice. The second subline, LY-S is UV254nm-resistant and nontumorigenic. Following treatment of these cells with 2 mM benzamide, an inhibitor of the NAD+-utilizing enzyme poly(ADP-ribose) polymerase, NAD+ levels slowly increased up to about 160% of control levels after 3 hours. When benzamide was added to these cultures 20 min
after UV254nm irradiation, a dramatic transient increase of NAD+ levels was observed within 4 min in LY-R cells and more moderately in LY-S cells. At later times after UV254nm irradiation, the NAD+ levels increased in both sublines reaching up to 200% of the concentrations prior to benzamide treatment. These results demonstrate
an adaptative response of NAD+ metabolism to UV254nm irradiation. In parallel, we observed a differential repartitioning of ADP-ribosyl residues between the NAD+ and poly(ADP-ribose) pools of LY-R and LY-S cells that correlates with the differential UV sensitivity of these cells. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|