Poly(ADP-ribosyl)ation of proteins is a posttranslational modification mediated by
poly(ADP-ribose) polymerases (PARPs) that use NAD+ as substrate to form the negatively
charged polymer of poly(ADP-ribose) (PAR). After DNA damage, PARP-1 is responsible
for approximately 90% of the total cellular PARylation activity. Numerous studies
showed activation of PARP-1 in various conditions associated with oxidative and nitrosative
stress, such as ischemia-reperfusion injury, diabetes mellitus, and inflammation,
and also proved the beneficial effects of PARP inhibitors. Several pharmacological
inhibitors of PARP moved toward clinical testing for a variety of indications, including
cardioprotection and malignant tumors, and in late 2014, olaparib became the first
PARP inhibitor approved for human use for the therapy of ovarian cancer. These advances
necessitate the detection of PARP activation in human tissues. In the present chapter,
we review specific methods used to detect PARP activation in human circulating leukocytes
and in human tissue sections.
