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PARP ‐1/ PAR Activity in Cultured Human Lens Epithelial Cells Exposed to Two Levels of UVB Light
Author(s) -
Cencer Caroline S.,
Chintala Shravan K.,
Townsend Tenira J.,
Feldmann Daniel P.,
Awrow Mirna A.,
Putris Nahrain A.,
Geno Mason E.,
Donovan Maria G.,
Giblin Frank J.
Publication year - 2017
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/php.12814
Subject(s) - poly adp ribose polymerase , viability assay , reactive oxygen species , apoptosis , mitochondrion , dna damage , programmed cell death , microbiology and biotechnology , dna repair , parp inhibitor , chemistry , biology , polymerase , dna , biochemistry
This study investigated poly( ADP ‐ribose) polymerase‐1 ( PARP ‐1) activation in cultured human lens epithelial cells exposed to two levels of UVB light (312 nm peak wavelength), 0.014 and 0.14 J cm −2 (“low” and “high” dose, respectively). At the low dose, PARP ‐1 and poly( ADP ‐ribose) ( PAR ) polymers acted to repair DNA strand breaks rapidly with no subsequent major effects on either cell morphology or viability. However, following the high UVB dose, there was a dramatic second phase of PARP ‐1 activation, 90 min later, which included a sudden reappearance of DNA strand breaks, bursts of reactive oxygen species ( ROS ) formation within both the mitochondria and nucleus, a translocation of PAR from the nucleus to the mitochondria and an ultimate 70% loss of cell viability occurring after 24 h. The results provide evidence for an important role for PARP ‐1 in protecting the human lens epithelium against low levels of UVB light, and possibly participating in the triggering of cell death following exposure to toxic levels of radiation.