scholarly journals Protection of Porcine Oocytes Against Apoptotic Cell Death Caused by Oxidative Stress During In Vitro Maturation: Role of Cumulus Cells1

2000 ◽  
Vol 63 (3) ◽  
pp. 805-810 ◽  
Author(s):  
Hideki Tatemoto ◽  
Noriaki Sakurai ◽  
Norio Muto
2002 ◽  
Vol 2 ◽  
pp. 943-948 ◽  
Author(s):  
Pidder Jansen-Dürr

Replicative senescence of human cells in primary culture is a widely accepted model for studying the molecular mechanisms of human ageing. The standard model used for studying human ageing consists of fibroblasts explanted from the skin and grown intoin vitrosenescence. From this model, we have learned much about molecular mechanisms underlying the human ageing process; however, the model presents clear limitations. In particular, a long-standing dogma holds that replicative senescence involves resistance to apoptosis, a belief that has led to considerable confusion concerning the role of apoptosis during human ageing. While there are data suggesting that apoptotic cell death plays a key role for ageingin vitroand in the pathogenesis of various age-associated diseases, this is not reflected in the current literature onin vitrosenescence. In this article, I summarize key findings concerning the relationship between apoptosis and ageingin vivoand also review the literature concerning the role of apoptosis during in vitro senescence. Recent experimental findings, summarized in this article, suggest that apoptotic cell death (and probably other forms of cell death) are important features of the ageing process that can also be recapitulated in tissue culture systems to some extent. Another important lesson to learn from these studies is that mechanisms ofin vivosenescence differ considerably between various histotypes.


2008 ◽  
Vol 294 (3) ◽  
pp. H1317-H1325 ◽  
Author(s):  
Jasna Marinovic ◽  
Marko Ljubkovic ◽  
Anna Stadnicka ◽  
Zeljko J. Bosnjak ◽  
Martin Bienengraeber

From time of their discovery, sarcolemmal ATP-sensitive K+ (sarcKATP) channels were thought to have an important protective role in the heart during stress whereby channel opening protects the heart from stress-induced Ca2+ overload and resulting damage. In contrast, some recent studies indicate that sarcKATP channel closing can lead to cardiac protection. Also, the role of the sarcKATP channel in apoptotic cell death is unclear. In the present study, the effects of channel inhibition on apoptosis and the specific interaction between the sarcKATP channel and mitochondria were investigated. Apoptotic cell death of cultured HL-1 and neonatal cardiomyocytes following exposure to oxidative stress was significantly increased in the presence of sarcKATP channel inhibitor HMR-1098 as evidenced by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling and caspase-3,7 assays. This was paralleled by an increased release of cytochrome c from mitochondria to cytosol, suggesting activation of the mitochondrial death pathway. sarcKATP channel inhibition during stress had no effect on Bcl-2, Bad, and phospho-Bad, indicating that the increase in apoptosis cannot be attributed to these modulators of the apoptotic pathway. However, monitoring of mitochondrial Ca2+ with rhod-2 fluorescent indicator revealed that mitochondrial Ca2+ accumulation during stress is potentiated in the presence of HMR-1098. In conclusion, this study provides novel evidence that opening of sarcKATP channels, through a specific Ca2+-related interaction with mitochondria, plays an important role in preventing cardiomyocyte apoptosis and mitochondrial damage during stress.


2015 ◽  
Vol 48 ◽  
pp. 68-76 ◽  
Author(s):  
Lucio G. Costa ◽  
Claudia Pellacani ◽  
Khoi Dao ◽  
Terrance J. Kavanagh ◽  
Pamela J. Roque

Microbiology ◽  
2014 ◽  
Vol 160 (6) ◽  
pp. 1101-1111 ◽  
Author(s):  
Jyotika Rajawat ◽  
Tina Alex ◽  
Hina Mir ◽  
Ashlesha Kadam ◽  
Rasheedunnisa Begum

Apoptosis involves a cascade of caspase activation leading to the ordered dismantling of critical cell components. However, little is known about the dismantling process in non-apoptotic cell death where caspases are not involved. Dictyostelium discoideum is a good model system to study caspase-independent cell death where experimental accessibility of non-apoptotic cell death is easier and molecular redundancy is reduced compared with other animal models. Poly(ADP-ribose) polymerase (PARP) is one of the key players in cell death. We have previously reported the role of PARP in development and the oxidative stress-induced cell death of D. discoideum. D. discoideum possesses nine PARP genes and does not have a caspase gene, and thus it provides a better model system to dissect the role of PARP in caspase-independent cell death. The current study shows that non-apoptotic cell death in D. discoideum occurs in a programmed fashion where proteases cause mitochondrial membrane potential changes followed by plasma membrane rupture and early loss of plasma membrane integrity. Furthermore, the results suggest that calpains and cathepsin D, which are instrumental in dismantling the cell, act downstream of PARP. Thus, PARP, apoptosis inducing factor, calpains and cathepsin D are the key players in D. discoideum caspase-independent cell death, acting in a sequential manner.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tong Zhao ◽  
Tihua Zheng ◽  
Huining Yu ◽  
Bo Hua Hu ◽  
Bing Hu ◽  
...  

AbstractMacroautophagy/autophagy is a highly conserved self-digestion pathway that plays an important role in cytoprotection under stress conditions. Autophagy is involved in hepatotoxicity induced by acetaminophen (APAP) in experimental animals and in humans. APAP also causes ototoxicity. However, the role of autophagy in APAP-induced auditory hair cell damage is unclear. In the present study, we investigated autophagy mechanisms during APAP-induced cell death in a mouse auditory cell line (HEI-OC1) and mouse cochlear explant culture. We found that the expression of LC3-II protein and autophagic structures was increased in APAP-treated HEI-OC1 cells; however, the degradation of SQSTM1/p62 protein, the yellow puncta of mRFP-GFP-LC3 fluorescence, and the activity of lysosomal enzymes decreased in APAP-treated HEI-OC1 cells. The degradation of p62 protein and the expression of lysosomal enzymes also decreased in APAP-treated mouse cochlear explants. These data indicate that APAP treatment compromises autophagic degradation and causes lysosomal dysfunction. We suggest that lysosomal dysfunction may be directly responsible for APAP-induced autophagy impairment. Treatment with antioxidant N-acetylcysteine (NAC) partially alleviated APAP-induced autophagy impairment and apoptotic cell death, suggesting the involvement of oxidative stress in APAP-induced autophagy impairment. Inhibition of autophagy by knocking down of Atg5 and Atg7 aggravated APAP-induced ER and oxidative stress and increased apoptotic cell death. This study provides a better understanding of the mechanism responsible for APAP ototoxicity, which is important for future exploration of treatment strategies for the prevention of hearing loss caused by ototoxic medications.


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