Miscarriage Research Today is a free monthly online journal that collates and summarizes the latest research about Miscarriage, including details on signs, symptoms, recurrent, pregnancy.

Failure to degrade poly(ADP-ribose) causes increased sensitivity to cytotoxicity and early embryonic lethality.

Koh DW, Lawler AM, Poitras MF, Sasaki M, Wattler S, Nehls MC, Stöger T, Poirier GG, Dawson VL, Dawson TM

Institute for Cell Engineering and Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.

The metabolism of poly(ADP-ribose) (PAR) is critical for genomic stability in multicellular eukaryotes. Here, we show that the failure to degrade PAR by means of disruption of the murine poly(ADP-ribose) glycohydrolase (PARG) gene unexpectedly causes early embryonic lethality and enhanced sensitivity to genotoxic stress. This lethality results from the failure to hydrolyze PAR, because PARG null embryonic day (E) 3.5 blastocysts accumulate PAR and concurrently undergo apoptosis. Moreover, embryonic trophoblast stem cell lines established from early PARG null embryos are viable only when cultured in medium containing the poly(ADP-ribose) polymerase inhibitor benzamide. Cells lacking PARG also show reduced growth, accumulation of PAR, and increased sensitivity to cytotoxicity induced by N-methyl-N'-nitro-N-nitrosoguanidine and menadione after benzamide withdrawal. These results provide compelling evidence that the failure to degrade PAR has deleterious consequences. Further, they define a role for PARG in embryonic development and a protective role in the response to genotoxic stress.

Published 22 December 2004 in Proc Natl Acad Sci U S A, 101(51): 17699-704.
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