ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Protein modification by ADP-ribose polymers is a common regulatory mechanism in eukaryotic cells and is involved in several aspects of brain physiology and physiopathology, including neurotransmission, memory formation, neurotoxicity, ageing and age-associated diseases. Here we show age-related misregulation of poly(ADP-ribose) synthesis in rat cerebellum as revealed by: (i) reduced poly(ADP-ribose) polymerase-1 (PARP-1) activation in response to enzymatic DNA cleavage, (ii) altered protein poly(ADP-ribosyl)ation profiles in isolated nuclei, and (iii) cell type-specific loss of poly(ADP-ribosyl)ation capacity in granule cell layer and Purkinje cells in vivo. In particular, although PARP-1 could be detected in virtually all granule cells, only a fraction of them appeared to be actively engaged in poly(ADP-ribose) synthesis and this fraction was reduced in old rat cerebellum. NAD+, quantified in tissue homogenates, was essentially the same in the cerebellum of young and old rats suggesting that in vivo factors other than PARP-1 content and/or NAD+ levels may be responsible for the age-associated lowering of poly(ADP-ribose) synthesis. Moreover, PARP-1 expression was substantially down-regulated in Purkinje cells of senescent rats.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.2005.03082.x
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