Involvement of Fas/FasL system in apoptotic signaling in testicular germ cells of male Wistar rats injected i.v. with microcystins.
Previous studies have shown that gonads were the second target organ of microcystins (MCs), and that MCs exposure exerted obvious toxic effects on male reproductive system of mammals. However, relevant molecular evidences are still lacking. Fas-signaling pathway plays a key role in toxicant-induced germ cell apoptosis. This study was to evaluate the responses of Fas/FasL system related genes and proteins in testes of rats injected intravenously with MCs. Enhanced apoptosis of germ cells in the testes of MCs-treated rats was detected by the terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick end labeling (TUNEL) associated with up-regulation of the Fas/FasL system. Both Fas and FasL protein expression were induced evidently from 1 h post-injection, and this high expression level maintained throughout the experiment. In addition, the activation of caspase-8 and caspase-3 protein was also observed, which were indicators of apoptosis. These results suggested the likely involvement of Fas/FasL system in the MCs-induced germ cell apoptosis. It is also suggested that MCs can cause damage to Sertoli cells directly.
Xiong
Qian
Q
Donghu Experimental Station of Lake Ecosystems, State Key Laboratory for Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China.
Xie
Ping
P
Li
Huiying
H
Hao
Le
L
Li
Guangyu
G
Qiu
Tong
T
Liu
Ying
Y
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053148:Caspase 3 / Q000096:biosynthesis / Q000235:genetics; D053181:Caspase 8 / Q000096:biosynthesis / Q000235:genetics; D000458:Cyanobacteria / Q000737:chemistry; D053222:Fas Ligand Protein / Q000502:physiology*; D005854:Germ Cells / Q000187:drug effects / Q000502:physiology*; D020287:In Situ Nick-End Labeling; D007928:Lethal Dose 50; D008297:Male; D052998:Microcystins / Q000008:administration & dosage / Q000633:toxicity*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects*; D013737:Testis / Q000166:cytology* / Q000187:drug effects
D053222:Fas Ligand Protein; D052998:Microcystins; D012333:RNA, Messenger; D053148:Caspase 3; D053181:Caspase 8