Mk 886 Functions As A Radiomimetic Agent: Genomic Responses Related to Oxidative Stress, The Cell Cycle, Proliferation and Programmed Cell Death in Panc-1 Cells

Author(s):  
Ken M. Anderson ◽  
Waddah Alrefai ◽  
Colin Anderson ◽  
Philip Bonomi ◽  
Jules Harris
2020 ◽  
Vol 31 (1) ◽  
pp. 3-10
Author(s):  
V. S. Nedzvetsky ◽  
V. Ya. Gasso ◽  
A. M. Hahut ◽  
I. A. Hasso

Cadmium is a common transition metal that entails an extremely wide range of toxic effects in humans and animals. The cytotoxicity of cadmium ions and its compounds is due to various genotoxic effects, including both DNA damage and chromosomal aberrations. Some bone diseases, kidney and digestive system diseases are determined as pathologies that are closely associated with cadmium intoxication. In addition, cadmium is included in the list of carcinogens because of its ability to initiate the development of tumors of several forms of cancer under conditions of chronic or acute intoxication. Despite many studies of the effects of cadmium in animal models and cohorts of patients, in which cadmium effects has occurred, its molecular mechanisms of action are not fully understood. The genotoxic effects of cadmium and the induction of programmed cell death have attracted the attention of researchers in the last decade. In recent years, the results obtained for in vivo and in vitro experimental models have shown extremely high cytotoxicity of sublethal concentrations of cadmium and its compounds in various tissues. One of the most studied causes of cadmium cytotoxicity is the development of oxidative stress and associated oxidative damage to macromolecules of lipids, proteins and nucleic acids. Brain cells are most sensitive to oxidative damage and can be a critical target of cadmium cytotoxicity. Thus, oxidative damage caused by cadmium can initiate genotoxicity, programmed cell death and inhibit their viability in the human and animal brains. To test our hypothesis, cadmium cytotoxicity was assessed in vivo in U251 glioma cells through viability determinants and markers of oxidative stress and apoptosis. The result of the cell viability analysis showed the dose-dependent action of cadmium chloride in glioma cells, as well as the generation of oxidative stress (p <0.05). Calculated for 48 hours of exposure, the LD50 was 3.1 μg×ml-1. The rates of apoptotic death of glioma cells also progressively increased depending on the dose of cadmium ions. A high correlation between cadmium concentration and apoptotic response (p <0.01) was found for cells exposed to 3–4 μg×ml-1 cadmium chloride. Moreover, a significant correlation was found between oxidative stress (lipid peroxidation) and induction of apoptosis. The results indicate a strong relationship between the generation of oxidative damage by macromolecules and the initiation of programmed cell death in glial cells under conditions of low doses of cadmium chloride. The presented results show that cadmium ions can induce oxidative damage in brain cells and inhibit their viability through the induction of programmed death. Such effects of cadmium intoxication can be considered as a model of the impact of heavy metal pollution on vertebrates.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kalyan Mahapatra ◽  
Sujit Roy

AbstractAs like in mammalian system, the DNA damage responsive cell cycle checkpoint functions play crucial role for maintenance of genome stability in plants through repairing of damages in DNA and induction of programmed cell death or endoreduplication by extensive regulation of progression of cell cycle. ATM and ATR (ATAXIA-TELANGIECTASIA-MUTATED and -RAD3-RELATED) function as sensor kinases and play key role in the transmission of DNA damage signals to the downstream components of cell cycle regulatory network. The plant-specific NAC domain family transcription factor SOG1 (SUPPRESSOR OF GAMMA RESPONSE 1) plays crucial role in transducing signals from both ATM and ATR in presence of double strand breaks (DSBs) in the genome and found to play crucial role in the regulation of key genes involved in cell cycle progression, DNA damage repair, endoreduplication and programmed cell death. Here we report that Arabidopsis exposed to high salinity shows generation of oxidative stress induced DSBs along with the concomitant induction of endoreduplication, displaying increased cell size and DNA ploidy level without any change in chromosome number. These responses were significantly prominent in SOG1 overexpression line than wild-type Arabidopsis, while sog1 mutant lines showed much compromised induction of endoreduplication under salinity stress. We have found that both ATM-SOG1 and ATR-SOG1 pathways are involved in the salinity mediated induction of endoreduplication. SOG1was found to promote G2-M phase arrest in Arabidopsis under salinity stress by downregulating the expression of the key cell cycle regulators, including CDKB1;1, CDKB2;1, and CYCB1;1, while upregulating the expression of WEE1 kinase, CCS52A and E2Fa, which act as important regulators for induction of endoreduplication. Our results suggest that Arabidopsis undergoes endoreduplicative cycle in response to salinity induced DSBs, showcasing an adaptive response in plants under salinity stress.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Ida Perrotta ◽  
Valentina Carito ◽  
Emilio Russo ◽  
Sandro Tripepi ◽  
Saveria Aquila ◽  
...  

The word autophagy broadly refers to the cellular catabolic processes that lead to the removal of damaged cytosolic proteins or cell organelles through lysosomes. Although autophagy is often observed during programmed cell death, it may also serve as a cell survival mechanism. Accumulation of reactive oxygen species within tissues and cells induces various defense mechanisms or programmed cell death. It has been shown that, besides inducing apoptosis, oxidative stress can also induce autophagy. To date, however, the regulation of autophagy in response to oxidative stress remains largely elusive and poorly understood. Therefore, the present study was designed to examine the ratio between oxidative stress and autophagy in macrophages after oxidant exposure (AAPH) and to investigate the ultrastructural localization of beclin-1, a protein essential for autophagy, under basal and stressful conditions. Our data provide evidence that oxidative stress induces autophagy in macrophages. We demonstrate, for the first time by immunoelectron microscopy, the subcellular localization of beclin-1 in autophagic cells.


FEBS Letters ◽  
1992 ◽  
Vol 311 (2) ◽  
pp. 174-178 ◽  
Author(s):  
S. El Alaoui ◽  
S. Mian ◽  
J. Lawry ◽  
G. Quash ◽  
M. Griffin

2018 ◽  
Author(s):  
Dustin Lane

Programmed cell death signaling networks are frequently activated to coordinate the process of cell differentiation, and a variety of apoptotic events can mediate the process. This can include the ligation of death receptors, the activation of downstream caspases, and the induction of chromatin fragmentation, and all of these events can occur without downstream induction of death. Importantly, regulators of programmed cell death also have established roles in mediating differentiation. This review will provide an overview of apoptosis and its regulation by Inhibitors of Apoptosis (IAPs) and Bcl-2 family members. It will then outline the cross-talk between NF-ĸB and apoptotic signaling in the regulation of apoptosis before discussing the function of these regulators in the control of cell differentiation. It will end on a discussion of how a DNA damage-directed, cell cycle-dependent differentiation program may be controlled across multiple passages through cell cycle, and will assert that the failure to properly differentiate is the underlying cause of cancer.


2020 ◽  
Vol 10 (18) ◽  
pp. 6509
Author(s):  
Magdalena Kimsa-Dudek ◽  
Agata Krawczyk ◽  
Agnieszka Synowiec-Wojtarowicz

A redox imbalance disrupts the cellcycle and the proliferation process, and contributes to the initiation of programmed cell death. One of the pathways that are important for redox homeostasis is the Nrf2-ARE signaling pathway. Fluoride as well as static magnetic fields (SMF) are associated with the concepts of oxidative stress, and thus programmed cell death. Therefore, this study aimed to assess the connection between oxidative stress and apoptosis in human cells co-exposed to fluoride and a SMF with a different magnetic induction and to determine whether the Nrf2-signaling pathway is involved in these effects. The research was realized using normal human dermal fibroblasts that had been co-exposed to fluoride (0.3 mmol/L) and a SMF with a different magnetic induction (0.45 T, 0.55 T, 0.65 T) for 12 h. The mRNA levels of the cellular antioxidant system-related genes and apoptosis-related genes were assessed using the quantitative reverse transcription polymerase chain reaction (RT-qPCR) method. Our results indicated that the increased activity of antioxidant enzymes (SOD1 (superoxide dismutase 1), SOD2 and GSR (glutathione reductase)) suggests the restoration of the cell redox homeostasis that had been disturbed by fluoride, and also that the genes whose expression is associated with the induction of apoptosis are down regulated as a result of exposure to a SMF. The SMF with a 0.65 T flux density had the strongest effect on the fibroblasts. Moreover, our findings demonstrated that the Nrf2 transcription factor plays a crucial role in the protective effect of a SMF against fluoride toxicity in human cells. The results of these studies can form the basis for developing therapeutic strategies for apoptosis and oxidative stress-related diseases.


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