scholarly journals A Novel Role of Listeria monocytogenes Membrane Vesicles in Inhibition of Autophagy and Cell Death

2017 ◽  
Vol 7 ◽  
Author(s):  
Svitlana Vdovikova ◽  
Morten Luhr ◽  
Paula Szalai ◽  
Lars Nygård Skalman ◽  
Monika K. Francis ◽  
...  
Keyword(s):  
Cell Death ◽  
Listeria Monocytogenes ◽  
Membrane Vesicles

scholarly journals Regulation of membrane release in apoptosis

1998 ◽  
Vol 334 (2) ◽  
pp. 479-485 ◽  
Author(s):  
Jiandi ZHANG ◽  
Timothy A. DRISCOLL ◽  
Yusuf A. HANNUN ◽  
Lina M. OBEID
Keyword(s):  
Cell Death ◽  
Membrane Lipids ◽  
Morphological Changes ◽  
Membrane Vesicles ◽  
Heterogeneous Population ◽  
Apoptotic Bodies ◽  
Fundamental Process ◽  
Release Assay ◽  
Lymphoid Cell Lines

Apoptosis is a fundamental process of cell regulation whereby cells execute one or more biochemical programs leading to cell death. Several mechanisms have been evaluated and suggested to play roles in the regulation of apoptosis, including the activation of phospholipase A2 (PLA2), usually measured as release of 3H-labelled arachidonic acid (AA) from prelabelled cells. The current study was aimed at examining the role of PLA2 in regulating apoptosis in response to several inducers (such as vincristine and etoposide) in lymphoid cell lines. Cells were labelled with [3H]fatty acids and the released radioactivity was characterized. These studies indicated that the AA release assay did not reflect release of non-esterified fatty acid via activation of the PLA2 pathway. Rather, studies using TLC and electron microscopy showed that AA release reflected a previously unsuspected shedding of a heterogeneous population of membrane vesicles and fragments, probably as components of apoptotic bodies. Further studies demonstrated that this process is an integral part of apoptosis. Overexpression of Bcl-2 or the addition of caspase peptide inhibitor benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethane prevented the characteristic morphological changes of cell death, and completely inhibited the release of membrane vesicles and fragments. On the other hand, release of membrane vesicles and fragments was caused by various inducers of apoptosis, as measured by release of either 3H-labelled AA or palmitic acid. Thus the present study demonstrates that the release of membrane lipids during apoptosis defines a new assay for apoptosis and has allowed the investigation of the mechanisms regulating formation of apoptotic bodies.

The role of programmed cell death ligand-1/ programmed cell death-1 (PD-L1/PD-1) in HPV-induced cervical cancer and potential for their use in blockade therapy

2020 ◽  
Vol 27 ◽  
Author(s):  
Lifang Zhang ◽  
Yu Zhao ◽  
Quanmei Tu ◽  
Xiangyang Xue ◽  
Xueqiong Zhu ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Immune Escape ◽  
Hypoxia Inducible Factor ◽  
Hpv Infection ◽  
Advanced Cervical Cancer ◽  
Cervical Carcinogenesis ◽  
Programmed Cell Death 1

Background: Cervical cancer induced by infection with human papillomavirus (HPV) remains a leading cause of mortality for women worldwide although preventive vaccines and early diagnosis have reduced morbidity and mortality. Advanced cervical cancer can only be treated with either chemotherapy or radiotherapy but outcomes are poor. The median survival for advanced cervical cancer patients is only 16.8 months. Methods: We undertook a structural search of peer-reviewed published studies based on 1). Characteristics of programmed cell death ligand-1/programmed cell death-1(PD-L1/PD-1) expression in cervical cancer and upstream regulatory signals of PD-L1/PD-1 expression, 2). The role of the PD-L1/PD-1 axis in cervical carcinogenesis induced by HPV infection and 3). Whether the PD-L1/PD-1 axis has emerged as a potential target for cervical cancer therapies. Results: One hundred and twenty-six published papers were included in the review, demonstrating that expression of PD-L1/PD-1 is associated with HPV-caused cancer, especially with HPV 16 and 18 which account for approximately 70% of cervical cancer cases. HPV E5/E6/E7 oncogenes activate multiple signaling pathways including PI3K/AKT, MAPK, hypoxia-inducible factor 1α, STAT3/NF-kB and MicroRNAs, which regulate PD-L1/PD-1 axis to promote HPV-induced cervical carcinogenesis. The PD-L1/PD-1 axis plays a crucial role in immune escape of cervical cancer through inhibition of host immune response. creating an "immune-privileged" site for initial viral infection and subsequent adaptive immune resistance, which provides a rationale for therapeutic blockade of this axis in HPV-positive cancers. Currently, Phase I/II clinical trials evaluating the effects of PD-L1/PD-1 targeted therapies are in progress for cervical carcinoma, which provide an important opportunity for the application of anti-PD-L1/anti-PD-1 antibodies in cervical cancer treatment. Conclusion: Recent research developments have led to an entirely new class of drugs using antibodies against the PD-L1/PD-1 thus promoting the body’s immune system to fight the cancer. The expression and roles of the PD-L1/ PD-1 axis in the progression of cervical cancer provide great potential for using PD-L1/PD-1 antibodies as a targeted cancer therapy.

scholarly journals Ozone-Induced Cell Death in Tobacco Cultivar Bel W3 Plants. The Role of Programmed Cell Death in Lesion Formation

2003 ◽  
Vol 133 (3) ◽  
pp. 1122-1134 ◽  
Author(s):  
Stefania Pasqualini ◽  
Claudia Piccioni ◽  
Lara Reale ◽  
Luisa Ederli ◽  
Guido Della Torre ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Lesion Formation ◽  
Tobacco Cultivar
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