Open AccessPhenyl 2‐pyridyl ketoxime induces cellular senescence‐like alterations via nitric oxide production in human diploid fibroblasts
Author(s) -
Yang Kyeong Eun,
Jang HyunJin,
Hwang InHu,
Chung YoungHo,
Choi JongSoon,
Lee TaeHoon,
Chung YunJo,
Lee MinSeung,
Lee Mi Young,
Yeo EuiJu,
Jang IkSoon
Publication year - 2016
Publication title -
aging cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.103
H-Index - 140
eISSN - 1474-9726
pISSN - 1474-9718
DOI - 10.1111/acel.12429
Subject(s) - senescence , catalase , nitric oxide , biology , reactive oxygen species , oxidative stress , nitric oxide synthase , flow cytometry , microbiology and biotechnology , peroxiredoxin , biochemistry , peroxidase , enzyme , endocrinology
Summary Phenyl‐2‐pyridyl ketoxime ( PPKO ) was found to be one of the small molecules enriched in the extracellular matrix of near‐senescent human diploid fibroblasts ( HDF s). Treatment of young HDF s with PPKO reduced the viability of young HDF s in a dose‐ and time‐dependent manner and resulted in senescence‐associated β‐galactosidase ( SA ‐β‐gal) staining and G2/M cell cycle arrest. In addition, the levels of some senescence‐associated proteins, such as phosphorylated ERK 1/2, caveolin‐1, p53, p16 ink4a , and p21 waf1 , were elevated in PPKO ‐treated cells. To monitor the effect of PPKO on cell stress responses, reactive oxygen species ( ROS ) production was examined by flow cytometry. After PPKO treatment, ROS levels transiently increased at 30 min but then returned to baseline at 60 min. The levels of some antioxidant enzymes, such as catalase, peroxiredoxin II and glutathione peroxidase I, were transiently induced by PPKO treatment. SOD II levels increased gradually, whereas the SOD I and III levels were biphasic during the experimental periods after PPKO treatment. Cellular senescence induced by PPKO was suppressed by chemical antioxidants, such as N‐acetylcysteine, 2,2,6,6‐tetramethylpiperidinyloxy, and L‐buthionine‐( S , R )‐sulfoximine. Furthermore, PPKO increased nitric oxide ( NO ) production via inducible NO synthase ( iNOS ) in HDF s. In the presence of NOS inhibitors, such as L‐ NG ‐nitroarginine methyl ester and L‐ NG ‐monomethylarginine, PPKO ‐induced transient NO production and SA ‐β‐gal staining were abrogated. Taken together, these results suggest that PPKO induces cellular senescence in association with transient ROS and NO production and the subsequent induction of senescence‐associated proteins .