scholarly journals Reactive oxygen species limit intestinal mucosa-bacteria homeostasis in vitro

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joshua Luchan ◽  
Christian Choi ◽  
Rebecca L. Carrier
Keyword(s):  
Reactive Oxygen Species ◽  
Oxidative Damage ◽  
Immune Cells ◽  
Bacterial Species ◽  
Cell Monolayer ◽  
Reactive Oxygen ◽  
Culture Period ◽  
Apical Surface ◽  
Oxygen Species

AbstractInteractions between epithelial and immune cells with the gut microbiota have wide-ranging effects on many aspects of human health. Therefore, there is value in developing in vitro models capable of performing highly controlled studies of such interactions. However, several critical factors that enable long term homeostasis between bacterial and mammalian cultures have yet to be established. In this study, we explored a model consisting of epithelial and immune cells, as well as four different bacterial species (Bacteroides fragilis KLE1958, Escherichia coli MG1655, Lactobacillus rhamnosus KLE2101, or Ruminococcus gnavus KLE1940), over a 50 hour culture period. Interestingly, both obligate and facultative anaerobes grew to similar extents in aerobic culture environments during the co-culture period, likely due to measured microaerobic oxygen levels near the apical surface of the epithelia. It was demonstrated that bacteria elicited reactive oxygen species (ROS) production, and that the resulting oxidative damage heavily contributed to observed epithelial barrier damage in these static cultures. Introduction of a ROS scavenger significantly mitigated oxidative damage, improving cell monolayer integrity and reducing lipid peroxidation, although not to control (bacteria-free culture) levels. These results indicate that monitoring and mitigating ROS accumulation and oxidative damage can enable longer term bacteria-intestinal epithelial cultures, while also highlighting the significance of additional factors that impact homeostasis in mammalian cell-bacteria systems.

scholarly journals Reactive Oxygen Species Limit Intestinal Mucosa-Bacteria Homeostasis in Vitro

2021 ◽  
Author(s):  
Joshua Luchan ◽  
Christian Choi ◽  
Rebecca L. Carrier
Keyword(s):  
Reactive Oxygen Species ◽  
Immune Cells ◽  
Bacterial Species ◽  
Cell Monolayer ◽  
Reactive Oxygen ◽  
Critical Parameters ◽  
Apical Surface ◽  
Oxygen Species ◽  
Aerobic Culture

Abstract The gut microbiome and its interactions with epithelial and immune cells have wide-ranging effects on many aspects of human health. Thus, in vitro models that enable highly controlled studies of these interactions are of value, yet critical parameters enabling long term homeostasis between bacteria and mammalian cultures have not been established. In this study, we developed a model incorporating epithelial and immune cells as well as different bacterial species (B. fragilis, E. coli, L. rhamnosus, or R. gnavus) over a 50 hour culture period. Interestingly, both obligate and facultative anaerobes grew to similar extents in aerobic culture environments in co-culture with epithelial and immune cells, potentially due to measured microaerobic oxygen levels near the epithelial apical surface. It was demonstrated that bacteria elicited reactive oxygen species (ROS) production, and that these species heavily contribute to observed epithelial barrier damage in these static cultures. Introduction of a ROS scavenger significantly mitigated ROS-mediated damage, improving cell monolayer integrity and reducing lipid peroxidation, although not to control (bacteria-free culture) levels. These results indicate that monitoring and mitigating ROS concentrations can enable longer term bacteria-intestinal epithelial cultures, but also highlight the significance of additional factors that impact homeostasis in mammalian cell-bacteria systems.

scholarly journals Ultraendurance exercise increases the production of reactive oxygen species in isolated mitochondria from human skeletal muscle

2010 ◽  
Vol 108 (4) ◽  
pp. 780-787 ◽  
Author(s):  
Kent Sahlin ◽  
Irina G. Shabalina ◽  
C. Mikael Mattsson ◽  
Linda Bakkman ◽  
Maria Fernström ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Oxidative Damage ◽  
Vastus Lateralis ◽  
Reactive Oxygen ◽  
Ros Production ◽  
Oxygen Species ◽  
Work Intensity ◽  
Isolated Mitochondria ◽  
Mitochondrial Ros

Exercise-induced oxidative stress is important for the muscular adaptation to training but may also cause muscle damage. We hypothesized that prolonged exercise would increase mitochondrial production of reactive oxygen species (ROS) measured in vitro and that this correlates with oxidative damage. Eight male athletes (24–32 yr) performed ultraendurance exercise (kayaking/running/cycling) with an average work intensity of 55% V̇o2peak for 24 h. Muscle biopsies were taken from vastus lateralis before exercise, immediately after exercise, and after 28 h of recovery. The production of H2O2 was measured fluorometrically in isolated mitochondria with the Amplex red and peroxidase system. Succinate-supported mitochondrial H2O2 production was significantly increased after exercise (73% higher, P = 0.025) but restored to the initial level at recovery. Plasma level of free fatty acids (FFA) increased fourfold and exceeded 1.2 mmol/l during the last 6 h of exercise. Plasma FFA at the end of exercise was significantly correlated to mitochondrial ROS production ( r = 0.74, P < 0.05). Mitochondrial content of 4-hydroxy-nonenal-adducts (a marker of oxidative damage) was increased only after recovery and was not correlated with mitochondrial ROS production. Total thiol group level and glutathione peroxidase activity were elevated after recovery. In conclusion, ultraendurance exercise increases ROS production in isolated mitochondria, but this is reversed after 28 h recovery. Mitochondrial ROS production was not correlated with oxidative damage of mitochondrial proteins, which was increased at recovery but not immediately after exercise.

The Role of Reactive Oxygen Species in Tumor Treatment and its Impact on Bone Marrow Hematopoiesis

2020 ◽  
Vol 21 (5) ◽  
pp. 477-498
Author(s):  
Yongfeng Chen ◽  
Xingjing Luo ◽  
Zhenyou Zou ◽  
Yong Liang
Keyword(s):  
Reactive Oxygen Species ◽  
Bone Marrow ◽  
Oxidative Damage ◽  
Tumor Cells ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Tumor Treatment ◽  
Normal Cells ◽  
Treatment And Prevention

Reactive oxygen species (ROS), an important molecule inducing oxidative stress in organisms, play a key role in tumorigenesis, tumor progression and recurrence. Recent findings on ROS have shown that ROS can be used to treat cancer as they accelerate the death of tumor cells. At present, pro-oxidant drugs that are intended to increase ROS levels of the tumor cells have been widely used in the clinic. However, ROS are a double-edged sword in the treatment of tumors. High levels of ROS induce not only the death of tumor cells but also oxidative damage to normal cells, especially bone marrow hemopoietic cells, which leads to bone marrow suppression and (or) other side effects, weak efficacy of tumor treatment and even threatening patients’ life. How to enhance the killing effect of ROS on tumor cells while avoiding oxidative damage to the normal cells has become an urgent issue. This study is a review of the latest progress in the role of ROS-mediated programmed death in tumor treatment and prevention and treatment of oxidative damage in bone marrow induced by ROS.

scholarly journals The Effects of Bioactive Compounds from Blueberry and Blackcurrant Powder on Oat Bran Pastes: Enhancing In Vitro Antioxidant Activity and Reducing Reactive Oxygen Species in Lipopolysaccharide-Stimulated Raw264.7 Macrophages

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 388
Author(s):  
Xiao Dan Hui ◽  
Gang Wu ◽  
Duo Han ◽  
Xi Gong ◽  
Xi Yang Wu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Antioxidant Capacity ◽  
Bioactive Compounds ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Raw264.7 Macrophages ◽  
Oat Bran

In this study, blueberry and blackcurrant powder were chosen as the phenolic-rich enrichments for oat bran. A Rapid Visco Analyser was used to form blueberry and blackcurrant enriched oat pastes. An in vitro digestion process evaluated the changes of phenolic compounds and the in vitro antioxidant potential of extracts of pastes. The anthocyanidin profiles in the extracts were characterised by the pH differential method. The results showed that blueberry and blackcurrant powder significantly increased the content of phenolic compounds and the in vitro antioxidant capacity of pastes, while the total flavonoid content decreased after digestion compared to the undigested samples. Strong correlations between these bioactive compounds and antioxidant values were observed. Lipopolysaccharide-stimulated RAW264.7 macrophages were used to investigate the intracellular antioxidant activity of the extracts from the digested oat bran paste with 25% enrichment of blueberry or blackcurrant powder. The results indicated that the extracts of digested pastes prevented the macrophages from experiencing lipopolysaccharide (LPS)-stimulated intracellular reactive oxygen species accumulation, mainly by the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) signalling pathway. These findings suggest that the bioactive ingredients from blueberry and blackcurrant powder enhanced the in vitro and intracellular antioxidant capacity of oat bran pastes, and these enriched pastes have the potential to be utilised in the development of the functional foods.

scholarly journals Targeting autophagy enhances atezolizumab-induced mitochondria-related apoptosis in osteosarcoma

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Zhuochao Liu ◽  
Hongyi Wang ◽  
Chuanzhen Hu ◽  
Chuanlong Wu ◽  
Jun Wang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Antitumor Immunity ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Specific Monoclonal Antibody ◽  
Osteosarcoma Cells ◽  
Jnk Pathway ◽  
In Vivo Experiments

AbstractIn this study, we identified the multifaceted effects of atezolizumab, a specific monoclonal antibody against PD-L1, in tumor suppression except for restoring antitumor immunity, and investigated the promising ways to improve its efficacy. Atezolizumab could inhibit the proliferation and induce immune-independent apoptosis of osteosarcoma cells. With further exploration, we found that atezolizumab could impair mitochondria of osteosarcoma cells, resulting in increased release of reactive oxygen species and cytochrome-c, eventually leading to mitochondrial-related apoptosis via activating JNK pathway. Nevertheless, the excessive release of reactive oxygen species also activated the protective autophagy of osteosarcoma cells. Therefore, when we combined atezolizumab with autophagy inhibitors, the cytotoxic effect of atezolizumab on osteosarcoma cells was significantly enhanced in vitro. Further in vivo experiments also confirmed that atezolizumab combined with chloroquine achieved the most significant antitumor effect. Taken together, our study indicates that atezolizumab can induce mitochondrial-related apoptosis and protective autophagy independently of the immune system, and targeting autophagy is a promising combinatorial approach to amplify its cytotoxicity.

scholarly journals The Effect of the Clenbuterol—β2-Adrenergic Receptor Agonist on the Peripheral Blood Mononuclear Cells Proliferation, Phenotype, Functions, and Reactive Oxygen Species Production in Race Horses In Vitro

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 936
Author(s):  
Olga Witkowska-Piłaszewicz ◽  
Rafał Pingwara ◽  
Jarosław Szczepaniak ◽  
Anna Winnicka
Keyword(s):  
Reactive Oxygen Species ◽  
Acute Exercise ◽  
Mononuclear Cells ◽  
Anabolic Steroids ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Peripheral Blood Mononuclear ◽  
Adrenoceptor Agonist ◽  
Race Horses

Clenbuterol, the β2-adrenoceptor agonist, is gaining growing popularity because of its effects on weight loss (i.e., chemical liposuction). It is also popular in bodybuilding and professional sports, due to its effects that are similar to anabolic steroids. However, it is prohibited by anti-doping control. On the other hand, it is suggested that clenbuterol can inhibit the inflammatory process. The cells from 14 untrained and 14 well-trained race horses were collected after acute exercise and cultured with clenbuterol. The expressions of CD4, CD8, FoxP3, CD14, MHCII, and CD5 in PBMC, and reactive oxygen species (ROS) production, as well as cell proliferation, were evaluated by flow cytometry. In addition, IL-1β, IL-4, IL-6, IL-10, IL-17, INF-γ and TNF-α concentrations were evaluated by ELISA. β2-adrenoceptor stimulation leads to enhanced anti-inflammatory properties in well-trained horses, as do low doses in untrained animals. In contrast, higher clenbuterol doses create a pro-inflammatory environment in inexperienced horses. In conclusion, β2-adrenoceptor stimulation leads to a biphasic response. In addition, the immune cells are more sensitive to drug abuse in inexperienced individuals under physical training.

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