scholarly journals Arsenite Effects on Mitochondrial Bioenergetics in Human and Mouse Primary Hepatocytes Follow a Nonlinear Dose Response

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Hemantkumar Chavan ◽  
Pamela Christudoss ◽  
Kristen Mickey ◽  
Robert Tessman ◽  
Hong-min Ni ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dose Response ◽  
Low Dose ◽  
Response Characteristic ◽  
Adaptive Responses ◽  
Primary Hepatocytes ◽  
Respiratory Complex I ◽  
Oxidant Production ◽  
Human And Mouse

Arsenite is a known carcinogen and its exposure has been implicated in a variety of noncarcinogenic health concerns. Increased oxidative stress is thought to be the primary cause of arsenite toxicity and the toxic effect is thought to be linear with detrimental effects reported at all concentrations of arsenite. But the paradigm of linear dose response in arsenite toxicity is shifting. In the present study we demonstrate that arsenite effects on mitochondrial respiration in primary hepatocytes follow a nonlinear dose response. In vitro exposure of primary hepatocytes to an environmentally relevant, moderate level of arsenite results in increased oxidant production that appears to arise from changes in the expression and activity of respiratory Complex I of the mitochondrial proton circuit. In primary hepatocytes the excess oxidant production appears to elicit adaptive responses that promote resistance to oxidative stress and a propensity to increased proliferation. Taken together, these results suggest a nonlinear dose-response characteristic of arsenite with low-dose arsenite promoting adaptive responses in a process known as mitohormesis, with transient increase in ROS levels acting as transducers of arsenite-induced mitohormesis.

scholarly journals Identification of Two Kinase Inhibitors with Synergistic Toxicity with Low-Dose Hydrogen Peroxide in Colorectal Cancer Cells In vitro

Cancers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 122 ◽  
Author(s):  
Eric Freund ◽  
Kim-Rouven Liedtke ◽  
Lea Miebach ◽  
Kristian Wende ◽  
Amanda Heidecke ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Colorectal Cancer ◽  
Hydrogen Peroxide ◽  
Protein Kinase ◽  
Tumor Cells ◽  
Low Dose ◽  
Kinase Inhibitors ◽  
Protein Kinase Inhibitors ◽  
Colorectal Cancer Cells

Colorectal carcinoma is among the most common types of cancers. With this disease, diffuse scattering in the abdominal area (peritoneal carcinosis) often occurs before diagnosis, making surgical removal of the entire malignant tissue impossible due to a large number of tumor nodules. Previous treatment options include radiation and its combination with intraperitoneal heat-induced chemotherapy (HIPEC). Both options have strong side effects and are often poor in therapeutic efficacy. Tumor cells often grow and proliferate dysregulated, with enzymes of the protein kinase family often playing a crucial role. The present study investigated whether a combination of protein kinase inhibitors and low-dose induction of oxidative stress (using hydrogen peroxide, H2O2) has an additive cytotoxic effect on murine, colorectal tumor cells (CT26). Protein kinase inhibitors from a library of 80 substances were used to investigate colorectal cancer cells for their activity, morphology, and immunogenicity (immunogenic cancer cell death, ICD) upon mono or combination. Toxic compounds identified in 2D cultures were confirmed in 3D cultures, and additive cytotoxicity was identified for the substances lavendustin A, GF109203X, and rapamycin. Toxicity was concomitant with cell cycle arrest, but except HMGB1, no increased expression of immunogenic markers was identified with the combination treatment. The results were validated for GF109203X and rapamycin but not lavendustin A in the 3D model of different colorectal (HT29, SW480) and pancreatic cancer cell lines (MiaPaca, Panc01). In conclusion, our in vitro data suggest that combining oxidative stress with chemotherapy would be conceivable to enhance antitumor efficacy in HIPEC.

scholarly journals Small extracellular vesicles convey the stress-induced adaptive responses of melanoma cells

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Maria Harmati ◽  
Edina Gyukity-Sebestyen ◽  
Gabriella Dobra ◽  
Laszlo Janovak ◽  
Imre Dekany ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Extracellular Vesicles ◽  
Stress Responses ◽  
In Silico ◽  
Specific Response ◽  
Response Patterns ◽  
Adaptive Responses ◽  
Mediated Communication ◽  
Ki 67

Abstract Exosomes are small extracellular vesicles (sEVs), playing a crucial role in the intercellular communication in physiological as well as pathological processes. Here, we aimed to study whether the melanoma-derived sEV-mediated communication could adapt to microenvironmental stresses. We compared B16F1 cell-derived sEVs released under normal and stress conditions, including cytostatic, heat and oxidative stress. The miRNome and proteome showed substantial differences across the sEV groups and bioinformatics analysis of the obtained data by the Ingenuity Pathway Analysis also revealed significant functional differences. The in silico predicted functional alterations of sEVs were validated by in vitro assays. For instance, melanoma-derived sEVs elicited by oxidative stress increased Ki-67 expression of mesenchymal stem cells (MSCs); cytostatic stress-resulted sEVs facilitated melanoma cell migration; all sEV groups supported microtissue generation of MSC-B16F1 co-cultures in a 3D tumour matrix model. Based on this study, we concluded that (i) molecular patterns of tumour-derived sEVs, dictated by the microenvironmental conditions, resulted in specific response patterns in the recipient cells; (ii) in silico analyses could be useful tools to predict different stress responses; (iii) alteration of the sEV-mediated communication of tumour cells might be a therapy-induced host response, with a potential influence on treatment efficacy.

scholarly journals Aloin Preconditioning Attenuates Hepatic Ischemia/Reperfusion Injury via Inhibiting TLR4/MyD88/NF-κB Signal Pathway In Vivo and In Vitro

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Yichao Du ◽  
Baolin Qian ◽  
Lin Gao ◽  
Peng Tan ◽  
Hao Chen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Inflammatory Response ◽  
Liver Tissue ◽  
Molecular Mechanisms ◽  
Ischemia Reperfusion ◽  
Primary Hepatocytes ◽  
Hepatic Ischemia ◽  
Hepatic Ischemia Reperfusion

Background. Aloin exerts considerable protective effects in various disease models, and its effect on hepatic ischemia-reperfusion (HIR) injury remains unknown. This research is aimed at conducting an in-depth investigation of the antioxidant, anti-inflammatory, and antiapoptosis effects of aloin in HIR injury and explain the underlying molecular mechanisms. Methods. In vivo, different concentrations of aloin were intraperitoneally injected 1 h before the establishment of the HIR model in male mice. The hepatic function, pathological status, oxidative stress, and inflammatory and apoptosis markers were measured. In vitro, aloin (AL, C21H22O9) or lipopolysaccharide (LPS) was added to a culture of mouse primary hepatocytes before it underwent hypoxia/reoxygenation (H/R), and the apoptosis in the mouse primary hepatocytes was analyzed. Results. We found that 20 mg/kg was the optimum concentration of aloin for mitigating I/R-induced liver tissue damage, characterized by decreased serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Aloin pretreatment substantially suppressed the generation of hepatic malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), and IL-6 and enhanced the hepatic superoxide dismutase (SOD) activities as well as glutathione (GSH) and IL-10 levels in the liver tissue of I/R mice; this indicated that aloin ameliorated I/R-induced liver damage by reducing the oxidative stress and inflammatory response. Moreover, aloin inhibited hepatocyte apoptosis and inflammatory response that was caused by the upregulated expression of Bcl-2, the downregulated expression of cleaved caspase3(C-caspase3), Bax, Toll-like receptor 4 (TLR4), FADD, MyD88, TRAF6, phosphorylated IKKα/β (p-IKKα/β), and phosphorylated nuclear factor κB p65 (p-NF-κB p65).

scholarly journals Intracellular cyclic AMP levels modulate differential adaptive responses on epimastigotes and cell culture trypomastigotes of Trypanosoma cruzi

2019 ◽  
Author(s):  
Tamara Sternlieb ◽  
Alejandra C. Schoijet ◽  
Guillermo D. Alonso
Keyword(s):  
Oxidative Stress ◽  
Trypanosoma Cruzi ◽  
Second Messengers ◽  
Redox Status ◽  
Adaptive Responses ◽  
Cellular Processes ◽  
The Many ◽  
Hemoglobin Degradation ◽  
Intracellular Second Messengers

ABSTRACTAmong the many environmental challenges the parasite Trypanosoma cruzi has to overcome to complete its life cycle through different hosts, oxidative stress plays a central role. Different stages of this parasite encounter distinct sources of oxidative stress, such as the oxidative burst of the immune system, or the Heme released from hemoglobin degradation in the triatomine’s midgut. Also, the redox status of the surroundings functions as a signal to the parasite, triggering processes coupled to differentiation or proliferation. Intracellular second messengers, like cAMP, are responsible for the transduction of environmental queues and initiating cellular processes accordingly. In trypanosomatids cAMP is involved in a variety of processes, including proliferation, differentiation, osmoregulation and quorum sensing. Trypanosomatid phosphodiesterases (PDE) show atypical pharmacological properties and some have been involved in key processes for the survival of the parasites, which validates them as attractive therapeutic targets. Our work here shows that cAMP modulates different processes according to parasite stage. Epimastigotes become more resistant to oxidative stress when pre-treated with cAMP analogs, while trypomastigotes do not alter their response to oxidative stress under the same treatment. However, cAMP analogs do increase trypomastigotes infectivity in vitro. Also, we show that TcrPDEA1, a functionally enigmatic phosphodiesterase with very high Km, is involved in the epimastigotes response to oxidative stress.

scholarly journals Fasting Drives Nrf2-Related Antioxidant Response in Skeletal Muscle

2020 ◽  
Vol 21 (20) ◽  
pp. 7780
Author(s):  
Daniele Lettieri-Barbato ◽  
Giuseppina Minopoli ◽  
Rocco Caggiano ◽  
Rossella Izzo ◽  
Mariarosaria Santillo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Energy Homeostasis ◽  
Antioxidant Response ◽  
Protective Mechanism ◽  
Related Factor ◽  
Adaptive Responses ◽  
Positive Role

A common metabolic condition for living organisms is starvation/fasting, a state that could play systemic-beneficial roles. Complex adaptive responses are activated during fasting to help the organism to maintain energy homeostasis and avoid nutrient stress. Metabolic rearrangements during fasting cause mild oxidative stress in skeletal muscle. The nuclear factor erythroid 2-related factor 2 (Nrf2) controls adaptive responses and remains the major regulator of quenching mechanisms underlying different types of stress. Here, we demonstrate a positive role of fasting as a protective mechanism against oxidative stress in skeletal muscle. In particular, by using in vivo and in vitro models of fasting, we found that typical Nrf2-dependent genes, including those controlling iron (e.g., Ho-1) and glutathione (GSH) metabolism (e.g., Gcl, Gsr) are induced along with increased levels of the glutathione peroxidase 4 (Gpx4), a GSH-dependent antioxidant enzyme. These events are associated with a significant reduction in malondialdehyde, a well-known by-product of lipid peroxidation. Our results suggest that fasting could be a valuable approach to boost the adaptive anti-oxidant responses in skeletal muscle.

Kaempferol’s Protective Effect on Ethanol-Induced Mouse Primary Hepatocytes Injury Involved in the Synchronous Inhibition of SP1, Hsp70 and CYP2E1

2018 ◽  
Vol 46 (05) ◽  
pp. 1093-1110 ◽  
Author(s):  
Bo Zhou ◽  
Zhihui Jiang ◽  
Xinping Li ◽  
Xiaoying Zhang
Keyword(s):  
Oxidative Stress ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Protective Mechanism ◽  
Primary Hepatocytes ◽  
Ethanol Group ◽  
Protein Levels ◽  
Cyp2e1 Expression ◽  
Factor Specificity ◽  
Specificity Protein

The mechanism of ethanol-induced hepatotoxicity was complicated, accompanied by the over-expressions of the cytochrome P450 2E1 (CYP2E1), heat shock protein 70 (Hsp70) and the nuclear factor specificity protein 1 (SP1). Kaempferol (Kaem) could protect the ethanol-induced hepatotoxicity likely by inhibiting the CYP2E1 expression and activity. This study investigated the protective mechanism(s) of kaempferol on ethanol-induced toxicity by dynamic alteration of SP1, Hsp70 and CYP2E1 among the nucleus and different organelles in hepatocytes. After ethanol treatment alone and co-incubation hepatocytes with kaempferol, protein levels of CYP2E1, Hsp70, and SP1 were determined in vitro (western blotting and immunofluorescence). Hepatocytes’ viability was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) methods. Glutathione (GSH) levels were evaluated for ethanol-induced oxidative stress. In the ethanol-treated hepatocytes, kaempferol decreased protein levels of CYP2E1 in both microsome and mitochondria, cytosolic Hsp70 and SP1 in nuclear and cytosol, and the oxidative stress and increased the cell viability compared to those of ethanol group. Collectively, our findings propose that the protective mechanism of kaempferol is involved in the synchronous, early and persistent inhibitions of mitochondrial and microsomal CYP2E1, cytosolic Hsp70 and nuclear and cytosolic SP1 in mouse primary hepatocytes’ injury induced by ethanol.

scholarly journals Xiaoyaosan Decoction, a Traditional Chinese Medicine, Inhibits Oxidative-Stress-Induced Hippocampus Neuron Apoptosis In Vitro

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Zhen-zhi Meng ◽  
Jing-hong Hu ◽  
Jia-xu Chen ◽  
Guang-xin Yue
Keyword(s):  
Oxidative Stress ◽  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Low Dose ◽  
Free Calcium ◽  
High Dose ◽  
Hippocampus Neuron ◽  
Neuron Apoptosis

Xiaoyaosan (XYS) decoction is a famous prescription for the treatment of mental disorders in China. In this experiment, we explored the way in which XYS decoction-reverse hippocampus neuron apoptosis in vitro. We used XYS decoction-containing serum to treat oxidative-stress-induced hippocampus neuron apoptosis and used immunofluorescence to determine the concentration of free calcium, mitochondrial membrane potential, and apoptotic rate of neuron. Results showed that 3-hour oxidative stress decrease mitochondrial membrane potential, increase the concentration of free calcium and apoptotic rate of neuron via triggering pathological changes of nucleus such as karyorrhexis, karyopyknosis. Low, medium, high dose of XYS-decoction-containing serum could reverse these phenomenon, and the effect of low-dose XYS-decoction-containing serum was significant in improving mitochondrial membrane potential and apoptotic rate of neuron. These findings suggest that XYS decoction may be helpful in reducing oxidative-stress-induced hippocampus neuron apoptosis.

The radiation-induced bystander effect: evidence and significance

2004 ◽  
Vol 23 (2) ◽  
pp. 61-65 ◽  
Author(s):  
Edouard I Azzam ◽  
John B Little
Keyword(s):  
Ionizing Radiation ◽  
Radiation Exposure ◽  
Low Dose ◽  
Bystander Effect ◽  
Current Knowledge ◽  
Biological Effects ◽  
High Dose ◽  
Adaptive Responses ◽  
Radiation Induced

A multitude of biological effects observed over the past two decades in various in vivo and in vitro cell culture experiments have indicated that low dose/low fluence ionizing radiation has significantly different biological responses than high dose radiation. Exposure of cell populations to very low fluences of particles or incorporated radionuclides results in significant biological effects occurring in both the irradiated and nonirradiated cells in the population. Cells recipient of growth medium from irradiated cultures can also respond to the radiation exposure. This phenomenon, termed the ‘bystander response’, has been postulated to impact both the estimation of risks of exposure to ionizing radiation and radiotherapy. Amplification of radiation-induced cyto-toxic and genotoxic effects by the bystander effect is in contrast to the observations of adaptive responses, which are generally induced following exposure to low dose, low linear energy transfer radiation and which tend to attenuate radiation-induced damage. In this article, the evidence for existence of radiation-induced bystander effects and our current knowledge of the biochemical and molecular events involved in mediating these effects are described. Potential similarities between factors that mediate the radiation-induced bystander and adaptive responses are highlighted.

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