Oxidative stress‐induced retinal damage is prevented by mild hypothermia in an ex vivo model of cultivated porcine retinas

Studies from animal models suggest that myocardial mitochondrial damage contributes to cardiac dysfunction after burn injury. In this report, we used an ex vivo model of primary cardiomyocyte culture to investigate the mechanisms of burn-induced mitochondrial impairment. Briefly, blood serum was collected from Sprague-Dawley (SD) rats subjected to 40% total body surface area burn and added (10% vol/vol) to primary cardiomyocytes prepared from SD rats. The effect of the burn serum on mitochondrial function and membrane integrity in the myocytes was analyzed. Exposure of myocytes to burn serum doubled the mitochondrial membrane damage measured by two independent assays. This treatment also significantly elevated mitochondrial oxidative stress, indicated by a more than 30% increase in lipid oxidation. Downregulation of mitochondrial antioxidant defense was also evident since the activities of the antioxidant enzymes superoxide dismutase and glutathione peroxidase were reduced by about 30% and 50%, respectively. Burn serum also induced deficiency of mitochondrial metabolism, indicated by a 30% decrease in the activity of cytochrome c oxidase. These mitochondrial dysfunctions appear to be generated by oxidative stress because burn serum induced a significant increase of mitochondrial oxygen species (mtROS) in cardiomyocytes, and pretreatment of cardiomyocytes with the antioxidant N-acetyl-cysteine prevented the mitochondrial damages induced by burn serum. Remarkably, the increase in mtROS was abolished by an antibody-mediated blockade of CD14. Furthermore, burn injury-induced mitochondrial damage in cardiomyocytes was prevented in CD14 knockout mice. Taken together, these data suggested that burn injury produces CD14-dependent mitochondrial damage via oxidative stress in myocardium.

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A Novel Porcine Ex Vivo Retina Culture Model for Oxidative Stress Induced by H2O2

Alternatives to Laboratory Animals ◽

10.1177/026119291704500105 ◽

2017 ◽

Vol 45 (1) ◽

pp. 11-25 ◽

Cited By ~ 14

Author(s):

José Hurst ◽

Sandra Kuehn ◽

Adelina Jashari ◽

Teresa Tsai ◽

Karl Ulrich Bartz-Schmidt ◽

...

Keyword(s):

Oxidative Stress ◽

Molecular Mechanisms ◽

Ganglion Cells ◽

Ex Vivo ◽

Laboratory Animals ◽

Ex Vivo Model ◽

Cd11b Expression ◽

Hsp70 Mrna ◽

New Therapeutic Approaches ◽

Culture Models

Oxidative stress is a key player in many ophthalmic diseases. However, the role of oxidative stress in most degenerative processes is not yet known. Therefore, accurate and practical models are required to efficiently screen for therapeutics. Porcine eyes are closely related to the human eye, and can be obtained from the abattoir as a by-product of the food industry. Therefore, they offer excellent opportunities for the development of culture models with which to pre-screen potential therapies, while reducing the use of laboratory animals. To induce oxidative stress, organotypic cultures of porcine retina were treated with different doses of hydrogen peroxide (H2O2; 100, 300 and 500μM) for three hours. On days 3 and 8, the retinas were conserved for histological and Western blotting analyses and for evaluation of gene expression, which determined the number of retinal ganglion cells (RGCs), the activation state of glial cells, and the expression levels of several oxidative stress markers. H2O2 treatment led to a reduction in the number of RGCs and to an increase in apoptotic RGCs. In addition, a dose-dependent increase of microglia and an elevation of CD11b expression was observed. On day 3, a reduction of IL-1β, and an increase of iNOS, as well as of HSP70 mRNA were found. On day 8, an increase in TNF-α and IL-1β mRNA expression was detected. In conclusion, this ex vivo model offers an opportunity to study the molecular mechanisms underlying certain eye disorders and to test new therapeutic approaches to diminish the effects of oxidative stress.

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Determining a Critical Threshold for G6PD Activity below which RBC Response to Oxidative Stress is Poor

10.21203/rs.2.19598/v2 ◽

2020 ◽

Author(s):

Maria Swastika ◽

Alida R Harahap ◽

Lydia V Panggalo ◽

Sri Widia A Jusman ◽

Ari W Satyagraha

Keyword(s):

Oxidative Stress ◽

G6pd Deficiency ◽

Ex Vivo ◽

Strong Association ◽

G6pd Activity ◽

Critical Threshold ◽

Main Function ◽

Ex Vivo Model ◽

Comparison Results ◽

Significant Difference

Abstract Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme disorder in the world. Its main function is to generate NADPH that is required for anti-oxidative pathway in the cells especially in RBC. G6PD deficiency is X-linked and thus subject to random X-chromosome inactivation in women giving them mosaic expression of G6PD activities in their individual cells. This phenomenon makes it difficult for diagnosis with the currently available G6PD qualitative diagnostic tests. With the rolling out of newly marketed anti-malarial drug tafenoquine which has a long half-life, screening for G6PD deficiency becomes a necessity where those with <70% G6PD activity cannot receive this drug. Thus, evidence for a quantitative cut-off for G6PD activity is needed to ensure safe drug administration. Methods: RBC models were developed to analyze the effect of oxidant on RBC oxidative markers namely total glutathione (GSH) and malondialdehyde (MDA). G6PD activity was measured using quantitative assay from Trinity Biotech and was correlated with cytofluorometric assay. RBC from two G6PD heterozygous women with different G6PD activities were also analyzed for comparison. Results: There was a negative correlation between G6PD activity and CuCl concentration and a strong association between G6PD activities and proportion of G6PD normal RBC in CuCl-treated models and in ex vivo RBC. However, in terms of oxidative stress markers analyses, unlike the hypothesis where the lower G6PD activity, the higher MDA and the lower GSH level, our CuCl RBC model showed that in low G6PD activities (10-30%) cells, the MDA level is lower compared to the rest of the models (p<0.05). Our ex vivo model however were in line with the hypothesis, although the result was not significant (p=0.5). There was a significant difference between RBC with <60% and those with >80% G6PD activities in CuCl RBC model but not in ex vivo RBC (p=0.5). Genotyping heterozygous subjects showed G6PD Viangchan variant with 2.97 U/gHb (33% activity) and 6.58 U/gHb (74% activity). Conclusions: The GSH analysis has pointed to the 60% G6PD activity cut-off and this data is supportive of the old WHO threshold for intermediate upper limit of 60% G6PD activity. However, there are significant limitations in using MDA assay with CuCl RBC model because the RBC was already stressed due to the copper treatment and thus present a different result when compared to the ex-vivo model.

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Reduced cyclic stretch, endothelial dysfunction, and oxidative stress: an ex vivo model

Cardiovascular Pathology ◽

10.1016/j.carpath.2009.06.007 ◽

2010 ◽

Vol 19 (4) ◽

pp. e91-e98 ◽

Cited By ~ 26

Author(s):

Tyler Thacher ◽

Veronica Gambillara ◽

Rafaela F. da Silva ◽

Paolo Silacci ◽

Nikos Stergiopulos

Keyword(s):

Oxidative Stress ◽

Endothelial Dysfunction ◽

Ex Vivo ◽

Cyclic Stretch ◽

Ex Vivo Model ◽

And Oxidative Stress

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Abstract 2487: Ischemia/Reperfusion Injury Impairs Myogenic Tone of Cerebral Vessels in both Ischemic and Nonischemic Hemispheres: Differential Role of Oxidative Stress.

Stroke ◽

10.1161/str.43.suppl_1.a2487 ◽

2012 ◽

Vol 43 (suppl_1) ◽

Author(s):

Maha Coucha ◽

Weiguo Li ◽

Adviye Ergul

Keyword(s):

Oxidative Stress ◽

Wistar Rats ◽

Ischemia Reperfusion Injury ◽

Ex Vivo ◽

Ischemia Reperfusion ◽

Cerebral Arteries ◽

Glucose Deprivation ◽

Myogenic Tone ◽

Ex Vivo Model

Cerebrovascular autoregulation and reactivity are critical to maintain constant perfusion during ischemic brain injury. It is known that ischemia/ reperfusion (I/R) injury and resulting oxidative stress impair vessel reactivity in ischemic hemisphere. Yet the behavior of vessels in nonischemic hemisphere is still unexplored. Hypothesis: I/R injury impairs myogenic tone of vessels in both ischemic and nonischemic hemispheres via increased peroxynitrite (ONOO - ) generation. Methods: Middle cerebral arteries (MCA) isolated from age matched male Wistar rats (n=6) subjected to 30 min MCA occlusion (MCAO)/45 min reperfusion, or MCAO followed by treatment with ONOO - scavenger FeTPPs (20mg/kg) at reperfusion were pressurized in arteriograph chamber. In another set of animals, MCA isolated from control Wistar rats were exposed to ex vivo oxygen-glucose deprivation (OGD) then their myogenic tones across the pressure range were determined. Results: I/R injury impaired myogenic tone of vessels in both ischemic and nonischemic sides albeit to a different degree. Interestingly FeTPPs restored myogenic tone of vessels from ischemic side only ( Table ). Vessels exposed to ex vivo and in vivo hypoxia experienced loss of myogenic tone. The reduction of myogenic tone % by OGD is similar to I/R injury. Conclusion: Our ex vivo model of hypoxia is a valuable method to assess the ischemic insult on vessel reactivity. Increased ONOO - production is one of the underlying mechanisms of loss of tone under I/R injury in ischemic hemisphere, but the impairment of myogenic tone in nonischemic hemisphere involves other mechanisms. Understanding how I/R alters myogenic tone and ultimately cerebral perfusion in both ischemic and nonischemic hemispheres is vital in improving current preventive and therapeutic strategies for acute stroke. + p<0.001, * p< 0.05 vs Sham, # p<0.001 vs ischemic MCA , ** p<0.01 vs nonischemic MCA

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1849: Systematic Evaluation of 21μm Thulium Laser Device for Treatment of Benign Prostatic Enlargement in an Ex-VIVO Model

The Journal of Urology ◽

10.1016/s0022-5347(18)32022-6 ◽

2007 ◽

Vol 177 (4S) ◽

pp. 614-614 ◽

Cited By ~ 3

Author(s):

Gunnar Wendt-Nordahl ◽

Stefanie Huckele ◽

Patrick Honeck ◽

Peter Aiken ◽

Thomas Knoll ◽

...

Keyword(s):

Ex Vivo ◽

Systematic Evaluation ◽

Thulium Laser ◽

Laser Device ◽

Benign Prostatic Enlargement ◽

Ex Vivo Model ◽

Prostatic Enlargement

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Assessment of phosphodiesterase inhibition and endothelin receptor antagonism combination therapy for pulmonary hypertension in a human ex vivo model

The Thoracic and Cardiovascular Surgeon ◽

10.1055/s-0032-1332505 ◽

2013 ◽

Vol 61 (S 01) ◽

Author(s):

M Ried ◽

M Hönicka ◽

T Potzger ◽

R Neu ◽

Z Sziklavari ◽

...

Keyword(s):

Pulmonary Hypertension ◽

Combination Therapy ◽

Ex Vivo ◽

Endothelin Receptor ◽

Phosphodiesterase Inhibition ◽

Ex Vivo Model ◽

Receptor Antagonism

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Porcine small intestine, a good ex vivo model to investigate absorption and metabolism of natural products

10.1055/s-0037-1608241 ◽

2017 ◽

Author(s):

J Houriet ◽

YE Arnold ◽

C Petit ◽

YN Kalia ◽

JL Wolfender

Keyword(s):

Natural Products ◽

Small Intestine ◽

Ex Vivo ◽

Ex Vivo Model

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Effects of Two Different Doses of Hirudin on APTT, Determined with Eight Different Reagents

Thrombosis and Haemostasis ◽

10.1055/s-0038-1653754 ◽

1995 ◽

Vol 73 (02) ◽

pp. 219-222 ◽

Cited By ~ 4

Author(s):

Manuel Monreal ◽

Luis Monreal ◽

Rafael Ruiz de Gopegui ◽

Yvonne Espada ◽

Ana Maria Angles ◽

...

Keyword(s):

Ex Vivo ◽

Anticoagulant Activity ◽

Subcutaneous Administration ◽

In Vitro Study ◽

Ex Vivo Model ◽

Suitable Candidate ◽

Significant Prolongation ◽

High Doses ◽

Different Doses

SummaryThe APTT has been considered the most suitable candidate to monitor the anticoagulant activity of hirudin. However, its use is hampered by problems of standardization, which make the results heavily dependent on the responsiveness of the reagent used. Our aim was to investigate if this different responsiveness of different reagents when added in vitro is to be confirmed in an ex vivo study.Two different doses of r-hirudin (CGP 39393), 0.3 mg/kg and 1 mg/kg, were administered subcutaneously to 20 New Zealand male rabbits, and the differences in prolongation of APTT 2 and 12 h later were compared, using 8 widely used commercial reagents. All groups exhibited a significant prolongation of APTT 2 h after sc administration of hirudin, both at low and high doses. But this prolongation persisted 12 h later only when the PTTa reagent (Boehringer Mannheim) was used. In general, hirudin prolonged the APTT most with the silica- based reagents.In a further study, we compared the same APTT reagents in an in vitro study in which normal pooled plasma was mixed with increasing amount of hirudin. We failed to confirm a higher sensitivity for silica- containing reagents. Thus, we conclude that subcutaneous administration of hirudin prolongs the APTT most with the silica-based reagents, but this effect is exclusive for the ex vivo model.

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