scholarly journals In Vivo Imaging of Reactive Oxygen Species in Mouse Brain by using [3H]Hydromethidine as a Potential Radical Trapping Radiotracer

2014 ◽  
Vol 34 (12) ◽  
pp. 1907-1913 ◽  
Author(s):  
Kohji Abe ◽  
Nozomi Takai ◽  
Kazumi Fukumoto ◽  
Natsumi Imamoto ◽  
Misato Tonomura ◽  
...  

To assess reactive oxygen species (ROS) production by detecting the fluorescent oxidation product, hydroethidine has been used extensively. The present study was undertaken to evaluate the potential of the hydroethidine derivative as a radiotracer to measure in vivo brain ROS production. [3H]-labeled N-methyl-2,3-diamino-6-phenyl-dihydrophenanthridine ([3H]Hydromethidine) was synthesized, and evaluated using in vitro radical-induced oxidization and in vivo brain ROS production model. In vitro studies have indicated that [3H]Hydromethidine is converted to oxidized products by a superoxide radical (O2• -) and a hydroxyl radical (OH• -) but not hydrogen peroxide (H2O2). In vivo whole-body distribution study showed that [3H]Hydromethidine rapidly penetrated the brain and then was washed out in normal mice. Microinjection of sodium nitroprusside (SNP) into the brain was performed to produce ROS such as OH• - via Fenton reaction. A significant accumulation of radioactivity immediately after [3H]Hydromethidine injection was seen in the side of the brain treated with SNP (5 and 20 nmol) compared with that in the contralateral side. These results indicated that [3H]Hydromethidine freely penetrated into the brain where it was rapidly converted to oxidized forms, which were trapped there in response to the production of ROS. Thus, [3H]Hydromethidine should be useful as a radical trapping radiotracer in the brain.

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Tomas Perecko ◽  
Katarina Drabikova ◽  
Antonin Lojek ◽  
Milan Ciz ◽  
Silvester Ponist ◽  
...  

It has been demonstrated that pterostilbene inhibits reactive oxygen species production in neutrophilsin vitro. However, little is known about its effects on neutrophils during inflammationin vivo. In this study, the effect of pterostilbene on neutrophil activity was investigated in experimental arthritis model. Lewis rats were injected by a single intradermal injection of heat-killedMycobacterium butyricumin Freund’s adjuvant to develop arthritis. Another group of arthritic animals received pterostilbene 30 mg/kg, daily, p.o. The number and activity of neutrophils in blood were measured on a weekly basis during the whole experiment. Moreover, the total radical trapping potential in plasma was measured at the end of the experiment. In the pterostilbene treated arthritic group, the treatment significantly lowered the number of neutrophils in blood on days 14 and 21 without significant downregulation of neutrophil oxidative burst. Pterostilbene nonsignificantly increased total radical trapping potential in arthritic animals. These results indicate that the promising effects of pterostilbene on reactive oxygen species operate by different mechanismsin vitroand in the animal model of inflammation. In conclusion, the positive effects of pterostilbene in the model of arthritis may be attributed to regulation of neutrophil number.


Author(s):  
Fangqiao Lv ◽  
Tinghui Shao ◽  
Yujia Xue ◽  
Xiulian Miao ◽  
Yan Guo ◽  
...  

Excessive accumulation of reactive oxygen species (ROS) is considered a major culprit for the pathogenesis of non-alcoholic fatty liver disease (NAFLD). We have previously shown that deletion of Brahma related gene 1 (BRG1) mitigated NAFLD in mice in part by attenuating ROS production in hepatocyte. Here we report that BRG1 deletion led to simultaneous down-regulation in expression and phosphorylation of tank binding kinase 1 (TBK1) in vivo and in vitro. On the one hand, BRG1 interacted with AP-1 to bind to the TBK1 promoter and directly activated TBK1 transcription in hepatocytes. On the other hand, BRG1 interacted with Sp1 to activate the transcription of c-SRC, a tyrosine kinase essential for TBK1 phosphorylation. Over-expression of c-SRC and TBK1 corrected the deficiency in ROS production in BRG1-null hepatocytes whereas depletion of TBK1 or c-SRC attenuated ROS production. In conclusion, our data suggest that dual regulation of TBK1 activity, at the transcription level and the post-transcriptional level, by BRG1 may constitute an important mechanism underlying excessive ROS production in hepatocytes.


2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Weixia Cai ◽  
Xuekang Yang ◽  
Shichao Han ◽  
Haitao Guo ◽  
Zhao Zheng ◽  
...  

Oxidative stress plays an important role in burn-induced myocardial injury, but the cellular mechanisms that control reactive oxygen species (ROS) production and scavenging are not fully understood. This study demonstrated that blockade of Notch signaling via knockout of the transcription factor RBP-J or a pharmacological inhibitor aggravated postburn myocardial injury, which manifested as deteriorated serum CK, CK-MB, and LDH levels and increased apoptosisin vitroandin vivo. Interruption of Notch signaling increased intracellular ROS production, and a ROS scavenger reversed the exacerbated myocardial injury after Notch signaling blockade. These results suggest that Notch signaling deficiency aggravated postburn myocardial injury through increased ROS levels. Notch signaling blockade also decreased MnSOD expressionin vitroandin vivo. Notably, Notch signaling blockade downregulated p-JAK2 and p-STAT3 expression. Inhibition of JAK2/STAT3 signaling with AG490 markedly decreased MnSOD expression, increased ROS production, and aggravated myocardial injury. AG490 plus GSI exerted no additional effects. These results demonstrate that Notch signaling protects against burn-induced myocardial injury through JAK2/STAT3 signaling, which activates the expression of MnSOD and leads to decreased ROS levels.


2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Zhuochao Liu ◽  
Hongyi Wang ◽  
Chuanzhen Hu ◽  
Chuanlong Wu ◽  
Jun Wang ◽  
...  

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.


2019 ◽  
Vol 20 (18) ◽  
pp. 4556 ◽  
Author(s):  
Hanna Zielinska-Blizniewska ◽  
Przemyslaw Sitarek ◽  
Anna Merecz-Sadowska ◽  
Katarzyna Malinowska ◽  
Karolina Zajdel ◽  
...  

Obesity is a complex disease of great public health significance worldwide: It entails several complications including diabetes mellitus type 2, cardiovascular dysfunction and hypertension, and its prevalence is increasing around the world. The pathogenesis of obesity is closely related to reactive oxygen species. The role of reactive oxygen species as regulatory factors in mitochondrial activity in obese subjects, molecules taking part in inflammation processes linked to excessive size and number of adipocytes, and as agents governing the energy balance in hypothalamus neurons has been examined. Phytotherapy is the traditional form of treating health problems using plant-derived medications. Some plant extracts are known to act as anti-obesity agents and have been screened in in vitro models based on the inhibition of lipid accumulation in 3T3-L1 cells and activity of pancreatic lipase methods and in in vivo high-fat diet-induced obesity rat/mouse models and human models. Plant products may be a good natural alternative for weight management and a source of numerous biologically-active chemicals, including antioxidant polyphenols that can counteract the oxidative stress associated with obesity. This review presents polyphenols as natural complementary therapy, and a good nutritional strategy, for treating obesity without serious side effects.


2018 ◽  
Vol 49 (6) ◽  
pp. 2320-2332 ◽  
Author(s):  
Guo Zu ◽  
Tingting Zhou ◽  
Ningwei Che ◽  
Xiangwen Zhang

Background/Aims: Ischemia-reperfusion (I/R) adversely affects the intestinal mucosa. The major mechanisms of I/R are the generation of reactive oxygen species (ROS) and apoptosis. Salvianolic acid A (SalA) is suggested to be an effective antioxidative and antiapoptotic agent in numerous pathological injuries. The present study investigated the protective role of SalA in I/R of the intestine. Methods: Adult male Sprague-Dawley rats were subjected to intestinal I/R injury in vivo. In vitro experiments were performed in IEC-6 cells subjected to hypoxia/ reoxygenation (H/R) stimulation to simulate intestinal I/R. TNF-α, IL-1β, and IL-6 levels were measured using enzyme-linked immunosorbent assay. Malondialdehyde and myeloperoxidase and glutathione peroxidase levels were measured using biochemical analysis. Apoptosis was measured by terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling staining or flow cytometry in vivo and in vitro. The level of reactive oxygen species (ROS) was measured by dichlorodihydrofluorescin diacetate (DCFH-DA) staining. Western blotting was performed to determine the expression of heme oxygenase-1 (HO-1), Nrf2 and proteins associated with apoptosis. The mRNA expressions of Nrf2 and HO-1 were detected by quantitative real-time polymerase chain reaction in vivo and in vitro. Results: Malondialdehyde level and myeloperoxidase and glutathione peroxidase, TNF-α, IL-1β, and IL-6 levels group in intestinal tissue decreased significantly in the SalA pretreatment groups compared to the I/R group. SalA markedly abolished intestinal injury compared to the I/R group. SalA significantly attenuated apoptosis and increased Nrf2/HO-1 expression in vivo and in vitro. However, Nrf2 siRNA treatment partially abrogated the above mentioned effects of SalA in H/R-induced ROS and apoptosis in IEC-6 cells. Conclusion: The present study demonstrated that SalA ameliorated oxidation, inhibited the release of pro-inflammatory cytokines and alleviated apoptosis in I/R-induced injury and that these protective effects may partially occur via regulation of the Nrf2/ HO-1 pathways.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
N. Pfeifer ◽  
D. M. Baston-Büst ◽  
J. Hirchenhain ◽  
U. Friebe-Hoffmann ◽  
D. T. Rein ◽  
...  

Background. The aim of this paper was to determine the influence of differentin vitroculture media on mRNA expression of Hedgehog genes,il-6,and important genes regarding reactive oxygen species in single mouse embryos.Methods. Reverse transcription of single embryos either culturedin vitrofrom day 0.5 until 3.5 (COOK’s Cleavage medium or Vitrolife’s G-1 PLUS medium) orin vivountil day 3.5post coitum. PCR was carried out forβ-actinfollowed by nested-PCR forshh, ihh, il-6, nox, gpx4, gpx1,andprdx2.Results. The number of murine blastocysts cultured in COOK medium which expressedil-6, gpx4, gpx1,andprdx2mRNA differed significantly compared to thein vivogroup. Except fornox, the mRNA profile of the Vitrolife media group embryos varied significantly from thein vivoones regarding the number of blastocysts expressing the mRNA ofshh, ihh, il-6, gpx4, gpx1andprdx2.Conclusions. The present study shows that differentin vitroculture media lead to different mRNA expression profiles during early development. Even the newly developedin vitroculture media are not able to mimic the female reproductive tract. The question of long-term consequences for children due to assisted reproduction techniques needs to be addressed in larger studies.


2020 ◽  
Vol 16 (3) ◽  
pp. e1008379 ◽  
Author(s):  
Artur Santos-Miranda ◽  
Julliane Vasconcelos Joviano-Santos ◽  
Grazielle Alves Ribeiro ◽  
Ana Flávia M. Botelho ◽  
Peter Rocha ◽  
...  

Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1661 ◽  
Author(s):  
Long Yuan ◽  
Rosalin Mishra ◽  
Hima Patel ◽  
Samar Alanazi ◽  
Xin Wei ◽  
...  

B-Rapidly Accelerated Fibrosarcoma (BRAF) mutations are found in about 50% of melanoma patients. Treatment with Food and Drug Administration (FDA)-approved BRAF and MAP/ERK kinase (MEK) inhibitors has improved progression free and overall survival of patients with BRAF mutant melanoma. However, all responders develop resistance typically within 1 year of treatment with these inhibitors. Evidence indicates that reactive oxygen species (ROS) levels are elevated after BRAF pathway inhibition treatment. We aim to decipher the role of mitochondrial antioxidant proteins relative to ROS levels and BRAF pathway inhibitor resistance. We observed BRAF mutant melanoma cells treated with the combination of a MEK inhibitor (trametinib) and a BRAF inhibitor (dabrafenib), exhibited elevated ROS levels, both in in vitro and in vivo melanoma models. We next generated trametinib- and dabrafenib-resistant (TDR) cells and found increased ROS levels after acquisition of resistance. An immunofluorescence experiment showed an increase of DNA damage in TDR cell lines. Furthermore, we observed that TDR cells increased superoxide dismutase 2 (SOD2), an antioxidant, at both mRNA and protein levels, with the upregulation of the transcription factor Nuclear Factor (NF)-κB. Knockdown of SOD2 significantly reduced the growth of BRAF pathway inhibitor-resistant cells. In addition, the results indicate that TDR cells can be re-sensitized to BRAF pathway inhibitors by the ROS scavenger, N-Acetyl Cysteine (NAC). Overall, these data indicate that BRAF pathway inhibitor-resistant cells can compensate for elevated ROS via increased expression of the antioxidant SOD2.


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