Faculty Opinions recommendation of Meiotic viral attenuation through an ancestral apoptotic pathway.

2019 ◽  
Author(s):  
Aaron Neiman
Keyword(s):  
Apoptotic Pathway ◽  
Viral Attenuation

scholarly journals Meiotic viral attenuation through an ancestral apoptotic pathway

2019 ◽  
Vol 116 (33) ◽  
pp. 16454-16462 ◽  
Author(s):  
Jie Gao ◽  
Sabrina Chau ◽  
Fuad Chowdhury ◽  
Tina Zhou ◽  
Saif Hossain ◽  
...  
Keyword(s):  
Budding Yeast ◽  
Apoptotic Pathway ◽  
Double Stranded Rna ◽  
Endonuclease G ◽  
Dying Cells ◽  
Viral Attenuation ◽  
Programmed Release

The programmed release of apoptogenic proteins from mitochondria is a core event of apoptosis, although ancestral roles of this phenomenon are not known. In mammals, one such apoptogenic protein is Endonuclease G (EndoG), a conserved mitochondrial nuclease that fragments the DNA of dying cells. In this work, we show that budding yeast executes meiotically programmed mitochondrial release of an EndoG homolog, Nuc1, during sporulation. In contrast to EndoG’s ostensible pro-death function during apoptosis, Nuc1 mitochondrial release is pro-survival, attenuating the cytosolic L-A and Killer double-stranded RNA mycoviruses and protecting meiotic progeny from the catastrophic consequences of their derepression. The protective viral attenuation role of this pathway illuminates a primordial role for mitochondrial release of EndoG, and perhaps of apoptosis itself.

scholarly journals Meiotic viral attenuation through an ancestral apoptotic pathway

2019 ◽  
Author(s):  
Jie Gao ◽  
Sabrina Chau ◽  
Fuad Chowdhury ◽  
Tina Zhou ◽  
Saif Hossain ◽  
...  
Keyword(s):  
Budding Yeast ◽  
Apoptotic Pathway ◽  
Endonuclease G ◽  
Dying Cells ◽  
Viral Attenuation ◽  
Dsrna Mycovirus ◽  
Programmed Release

AbstractThe programmed release of apoptogenic proteins from mitochondria is a core event of apoptosis, though ancestral roles of this phenomenon are not known. In mammals, one such apoptogenic protein is Endonuclease G (EndoG), a conserved nuclease that fragments the DNA of dying cells. In this work, we show that budding yeast executes meiotically programmed mitochondrial release of an EndoG homologue, Nuc1, during sporulation. In contrast to EndoG’s ostensible pro-death function during apoptosis, Nuc1 mitochondrial release attenuates the cytosolic dsRNA mycovirus, Killer, protecting spores from a lethal accumulation of its encoded toxin. Our identification of cell-protective viral attenuation as a target of this rudimentary apoptotic pathway illuminates a primordial role for mitochondrial release of EndoG.One Sentence SummaryYeast sporulation induces release of mitochondrial endonuclease G to accomplish viral attenuation.

Apoptosis and development

2003 ◽  
Vol 39 ◽  
pp. 11-24 ◽  
Author(s):  
Justin V McCarthy
Keyword(s):  
Drosophila Melanogaster ◽  
Mammalian Cells ◽  
Cell Number ◽  
Model Organisms ◽  
Biological Processes ◽  
Nematode Caenorhabditis Elegans ◽  
Apoptotic Pathway ◽  
Genetic Pathways ◽  
Evolutionarily Conserved ◽  
Multicellular Organisms

Apoptosis is an evolutionarily conserved process used by multicellular organisms to developmentally regulate cell number or to eliminate cells that are potentially detrimental to the organism. The large diversity of regulators of apoptosis in mammalian cells and their numerous interactions complicate the analysis of their individual functions, particularly in development. The remarkable conservation of apoptotic mechanisms across species has allowed the genetic pathways of apoptosis determined in lower species, such as the nematode Caenorhabditis elegans and the fruitfly Drosophila melanogaster, to act as models for understanding the biology of apoptosis in mammalian cells. Though many components of the apoptotic pathway are conserved between species, the use of additional model organisms has revealed several important differences and supports the use of model organisms in deciphering complex biological processes such as apoptosis.

The apoptotic pathway is disturbed in the active and inactive celiac disease

2001 ◽  
Vol 120 (5) ◽  
pp. A131-A131
Author(s):  
J VANDERWOUDE ◽  
T TIEBOSCH ◽  
M HOMAN ◽  
A BEUVING ◽  
J KLEIBEUKER ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Apoptotic Pathway

The warburg effect and tumour cell survival in human GBMs

2007 ◽  
Vol 30 (4) ◽  
pp. 97 ◽  
Author(s):  
A Wolf ◽  
J Mukherjee ◽  
A Guha
Keyword(s):  
Cytochrome C ◽  
Cell Survival ◽  
Expression Profile ◽  
Tumour Cell ◽  
Warburg Effect ◽  
Glycolytic Enzymes ◽  
Cytochrome C Release ◽  
Apoptotic Pathway ◽  
The Warburg Effect

Introduction: GBMs are resistant to apoptosis induced by the hypoxic microenvironment and standard therapies including radiation and chemotherapy. We postulate that the Warburg effect, a preferential glycolytic phenotype of tumor cells even under aerobic conditions, plays a role in these aberrant pro-survival signals. In this study we quantitatively examined the expression profile of hypoxia-related glycolytic genes within pathologically- and MRI-defined “centre” and “periphery” of GBMs. We hypothesize that expression of hypoxia-induced glycolytic genes, particularly hexokinase 2 (HK2), favours cell survival and modulates resistance to tumour cell apoptosis by inhibiting the intrinsic mitochondrial apoptotic pathway. Methods: GBM patients underwent conventional T1-weighted contrast-enhanced MRI and MR spectroscopy studies on a 3.0T GE scanner, prior to stereotactic sampling (formalin and frozen) from regions which were T1-Gad enhancing (“centre”) and T2-positive, T1-Gad negative (“periphery”). Real-time qRT-PCR was performed to quantify regional gene expression of glycolytic genes including HK2. In vitro functional studies were performed in U87 and U373 GBM cell lines grown in normoxic (21% pO2) and hypoxic (< 1%pO2) conditions, transfected with HK2 siRNA followed by measurement of cell proliferation (BrdU), apoptosis (activated caspase 3/7, TUNEL, cytochrome c release) and viability (MTS assay). Results: There exists a differential expression profile of glycolytic enzymes between the hypoxic center and relatively normoxic periphery of GBMs. Under hypoxic conditions, there is increased expression of HK2 at the mitochondrial membrane in GBM cells. In vitro HK2 knockdown led to decreased cell survival and increased apoptosis via the intrinsic mitochondrial pathway, as seen by increased mitochondrial release of cytochrome-C. Conclusions: Increased expression of HK2 in the centre of GBMs promotes cell survival and confers resistance to apoptosis, as confirmed by in vitro studies. In vivo intracranial xenograft studies with injection of HK2-shRNA are currently being performed. HK2 and possibly other glycolytic enzymes may provide a target for enhanced therapeutic responsiveness thereby improving prognosis of patients with GBMs.

Activation of the intrinsic-apoptotic pathway in LNCaP prostate cancer cells by genistein- topotecan combination treatments

2013 ◽  
Vol 3 (3) ◽  
pp. 66 ◽  
Author(s):  
Vanessa Hörmann ◽  
Sivanesan Dhandayuthapani ◽  
James Kumi-Diaka ◽  
Appu Rathinavelu
Keyword(s):  
Prostate Cancer ◽  
Cell Death ◽  
Cancer Cells ◽  
Apoptotic Cell ◽  
Treatment Options ◽  
Attractive Alternative ◽  
Intrinsic Apoptotic Pathway ◽  
Prostate Cancer Cells ◽  
Apoptotic Pathway ◽  
Combination Treatments

Background: Prostate cancer is the second most common cancer in American men. The development of alternative preventative and/or treatment options utilizing a combination of phytochemicals and chemotherapeutic drugs could be an attractive alternative compared to conventional carcinoma treatments. Genistein isoflavone is the primary dietary phytochemical found in soy and has demonstrated anti-tumor activities in LNCaP prostate cancer cells. Topotecan Hydrochloride (Hycamtin) is an FDA-approved chemotherapy for secondary treatment of lung, ovarian and cervical cancers. The purpose of this study was to detail the potential activation of the intrinsic apoptotic pathway in LNCaP prostate cancer cells through genistein-topotecan combination treatments. Methods: LNCaP cells were cultured in complete RPMI medium in a monolayer (70-80% confluency) at 37ºC and 5% CO2. Treatment consisted of single and combination groups of genistein and topotecan for 24 hours. The treated cells were assayed for i) growth inhibition through trypan blue exclusion assay and microphotography, ii) classification of cellular death through acridine/ ethidium bromide fluorescent staining, and iii) activation of the intrinsic apoptotic pathway through Jc-1: mitochondrial membrane potential assay, cytochrome c release and Bcl-2 protein expression.Results: The overall data indicated that genistein-topotecan combination was significantly more efficacious in reducing the prostate carcinoma’s viability compared to the single treatment options. In all treatment groups, cell death occurred primarily through the activation of the intrinsic apoptotic pathway.Conclusion: The combination of topotecan and genistein has the potential to lead to treatment options with equal therapeutic efficiency as traditional chemo- and radiation therapies, but lower cell cytotoxicity and fewer side effects in patients. Key words: topotecan; genistein; intrinsic apoptotic cell death

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