N-acetyl-L-cysteine counteracts oxidative stress and prevents H2O2 induced germ cell apoptosis through down-regulation of caspase-9 and JNK/c-Jun.
The mechanism of H(2)O(2) induced oxidative stress leading to male germ cell apoptosis was earlier reported from our laboratory. In the present study, we investigated the mechanisms by which N-acetyl-L-cysteine (NAC, which is highly cell specific with strong antioxidant and anti-genotoxic properties), stimulated cell survival under such conditions. Co-incubation with 5 mM NAC significantly (P<0.001) reduced the germ cell apoptosis induced by 10 µM H(2)O(2). Lipid peroxidation was brought down with significant restoration of activities of antioxidant enzymes, SOD, GST, and catalase. Expression of pro-apoptotic marker, Bax up-regulated following H(2)O(2) exposure, was reversed back to control levels. In contrast, expression of anti-apoptotic Bcl-2 and phospho-Akt revealed a completely opposite trend. While caspase-8 activity remained unaffected, NAC successfully attenuated the increased activities of caspase-3 and -9 in the H(2) O(2) treated cells. Simultaneously, the increased expression of caspase-9, phospho-JNK, and phospho-c-Jun after H(2)O(2) treatment was down-regulated by NAC. The above findings indicate that the mechanism of inhibition of H(2)O(2) induced male germ cell apoptosis by NAC is mediated through regulation of caspase-9 and JNK.
Department of Reproductive Biomedicine, National Institute of Health and Family Welfare, Baba Gang Nath Marg, New Delhi, India.
Ankur
A
Maheshwari
Man M
MM
Misro
Archana
A
Aggarwal
Rajnesh K
RK
Sharma
Deoki
D
Nandan
D000111:Acetylcysteine / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D019254:Genes, bcl-2; D005854:Germ Cells / Q000378:metabolism; D051549:Glutathione S-Transferase pi / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000633:toxicity*; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013482:Superoxide Dismutase / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D051028:bcl-2-Associated X Protein / Q000378:metabolism
D017382:Reactive Oxygen Species; D051028:bcl-2-Associated X Protein; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase; D051549:Glutathione S-Transferase pi; C496558:Gstp1 protein, rat; D051057:Proto-Oncogene Proteins c-akt; D048031:JNK Mitogen-Activated Protein Kinases; C505528:Casp8 protein, rat; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D000111:Acetylcysteine