Hormonal control of apoptotic cell death in the testis: gonadotropins and androgens as testicular cell survival factors

1993 ◽  
Vol 7 (5) ◽  
pp. 643-650 ◽  
Author(s):  
J. S. Tapanainen
Keyword(s):  
Cell Death ◽  
Cell Survival ◽  
Apoptotic Cell ◽  
Hormonal Control ◽  
Apoptotic Cell Death ◽  
Testicular Cell ◽  
Survival Factors

Protein Phosphatase 2A Inactivates Bcl2’s Antiapoptotic Function by Dephosphorylation and Up-Regulation of Bcl2-p53 Binding.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1436-1436
Author(s):  
Xingming Deng ◽  
Fengqin Gao ◽  
Tammy Flagg ◽  
W. Stratford May
Keyword(s):  
Cell Death ◽  
Cell Survival ◽  
Okadaic Acid ◽  
Protein Phosphatase ◽  
Apoptotic Cell ◽  
Protein Phosphatase 2A ◽  
Survival Function ◽  
Phosphorylation Site ◽  
Apoptotic Cell Death ◽  
Phosphatase 2A

Abstract DNA damage-induced p53/Bcl2 interaction at the outer mitochondrial membranes results in a Bcl2 conformational change and loss of its antiapoptotic function. Our data now indicate that either treatment of cells with the protein phosphatase 2A (PP2A) inhibitor, okadaic acid (10 nM), or specific disruption of PP2A activity by the expression of SV40 small tumor antigen enhances Bcl2 phosphorylation and suppresses the cisplatin-stimulated Bcl2-p53 interaction in association with prolonged cell survival. By contrast, C2-ceramide, a potent PP2A activator, reduces Bcl2 phosphorylation and increases Bcl2-p53 binding and promotes apoptotic cell death, suggesting that PP2A may function as a physiological regulator of Bcl2 by, at least in part, affecting its association with p53. Overexpression of the PP2A catalytic subunit (PP2A/C) suppresses Bcl2 phosphorylation in association with increased p53-Bcl2 binding and apoptotic cell death. By contrast, specific depletion of PP2A/C by RNA interference enhances Bcl2 phosphorylation, suppresses p53-Bcl2 interaction and prolongs cell survival. Purified PP2A can directly enhance the formation of the p53-Bcl2 complex in vitro in an okadaic acid-sensitive manner, supporting a direct mechanism. Importantly, PP2A directly interacts with Bcl2 at its BH4 domain which may function as the PP2A ‘docking site’ to potentially ‘bridge’ PP2A to the flexible loop domain which contains the physiological serine 70 phosphorylation site. Thus, PP2A may provide a double whammy to Bcl2’s survival function by both dephosphorylating and enhancing p53-Bcl2 binding. Therapeutically stimulating Bcl2 dephosphorylation and/or increasing Bcl2/p53 binding by activating PP2A may represent an efficient and novel antineoplastic approach.

scholarly journals Hypoxia/re-oxygenation-induced, redox-dependent activation of STAT1 (signal transducer and activator of transcription 1) confers resistance to apoptotic cell death via hsp70 induction

2004 ◽  
Vol 380 (1) ◽  
pp. 203-209 ◽  
Author(s):  
Keita TERUI ◽  
Sanae HAGA ◽  
Shin ENOSAWA ◽  
Naomi OHNUMA ◽  
Michitaka OZAKI
Keyword(s):  
Cell Death ◽  
Cell Survival ◽  
Apoptotic Cell ◽  
Specific Inhibitor ◽  
Apoptotic Cell Death ◽  
Janus Kinase ◽  
Serine Phosphorylation ◽  
Dependent Manner ◽  
Signal Transducer ◽  
Hsp70 Induction

STAT1 (signal transducer and activator of transcription 1) is potentially involved in cell survival, as well as cell death, in different types of cells. The present study was designed to examine the effects of STAT1 on hypoxia/re-oxygenation (H/R)-induced cell death and/or survival, and the underlying mechanisms of any such effects. H/R was shown to induce apoptotic cell death of rat hepatocytes. The addition of a STAT1-specific inhibitor, fludarabine, significantly increased the fraction of apoptotic cells after H/R. Following H/R, STAT1 was activated and sequential phosphorylation of Tyr701 and Ser727 was observed, which could be inhibited by the antioxidant N-acetyl-l-cysteine. Tyrosine and serine phosphorylation of STAT1 was mediated by Janus kinase 2 and phosphoinositide 3-kinase/Akt kinase respectively in a redox-dependent manner following H/R. STAT1-induced HSP70 (heat-shock protein 70) expression and the suppression of apoptosis occurred concomitantly. In conclusion, STAT1 activation, in a redox-dependent manner, following H/R may play crucial roles in cell survival, at least partly via HSP70 induction.

Non‐apoptotic cell death such as pyroptosis, autophagy, necroptosis and ferroptosis acts as partners to induce testicular cell death after scrotal hyperthermia in mice

Andrologia ◽  
2021 ◽  
Author(s):  
Amirhosein Hasani ◽  
Amirreza Khosravi ◽  
Paria Behnam ◽  
Fahim Ramezani ◽  
Bahram Eslami Farsani ◽  
...  
Keyword(s):  
Cell Death ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Testicular Cell
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