Induction of oxidative stress and apoptosis by PFOS and PFOA in primary cultured hepatocytes of freshwater tilapia (Oreochromis niloticus).
Perfluorinated organic compounds (PFOCs) are emerging persistent organic pollutants (POPs) widely present in the environment, wildlife and human. We studied the cellular toxicology of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) on oxidative stress and induction of apoptosis in primary cultured hepatocytes of freshwater tilapia (Oreochromis niloticus). Cultured hepatocytes were exposed to PFOS or PFOA (0, 1, 5, 15 and 30 mg L(-1)) for 24h, and a dose-dependent decrease in cell viability was determined using trypan blue exclusion method. Significant induction of reactive oxygen species (ROS) accompanied by increases in activities of superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) were found, while activities of glutathione peroxidase (GPx) and glutathione-S-transferase (GST) were decreased. Glutathione (GSH) content was reduced following treatment of PFOA and PFOS. A dose-dependent increase in the lipid peroxidation (LPO) level (measured as maleic dialdehyde, MDA) was observed only in the PFOA exposure groups, whereas LPO remained unchanged in the PFOS exposure groups. Furthermore, a significant activation of caspase-3, -8, -9 activities was evident in both PFOS and PFOA exposure groups. Typical DNA fragmentation (DNA laddering) was further characterized by agarose gel electrophoresis. The overall results demonstrated that PFOS and PFOA are able to produce oxidative stress and induce apoptosis with involvement of caspases in primary cultured tilapia hepatocytes.
Liu
Chunsheng
C
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China.
Yu
Ke
K
Shi
Xiongjie
X
Wang
Jingxian
J
Lam
Paul K S
PK
Wu
Rudolf S S
RS
Zhou
Bingsheng
B
D017738:Alkanesulfonic Acids / Q000633:toxicity*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002210:Caprylates / Q000633:toxicity*; D020169:Caspases / Q000032:analysis / Q000187:drug effects / Q000378:metabolism; D023681:Cichlids / Q000502:physiology*; D053938:DNA Fragmentation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004798:Enzymes / Q000032:analysis / Q000187:drug effects; D005466:Fluorocarbons / Q000633:toxicity*; D005618:Fresh Water; D005978:Glutathione / Q000032:analysis; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects*; D015227:Lipid Peroxidation / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D017738:Alkanesulfonic Acids; D002210:Caprylates; D004798:Enzymes; D005466:Fluorocarbons; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid; D020169:Caspases; D005978:Glutathione