Ex Vivo and in Vitro Models in Acetaminophen Hepatotoxicity Studies. Relationship between Glutathione Depletion, Oxidative Stress and Disturbances in Calcium Homeostasis and Energy Metabolism

Author(s):  
S. Ellouk-Achard ◽  
V. Levresse ◽  
C. Martin ◽  
C. Pham-Huy ◽  
H. Dutertre-Catella ◽  
...  
Author(s):  
Edward C. T. Waters ◽  
Friedrich Baark ◽  
Zilin Yu ◽  
Filipa Mota ◽  
Thomas R. Eykyn ◽  
...  

Abstract Purpose To determine the sensitivity of the 18F-radiolabelled dihydroethidine analogue ([18F]DHE) to ROS in a validated ex vivo model of tissue oxidative stress. Procedures The sensitivity of [18F]DHE to various ROS-generating systems was first established in vitro. Then, isolated rat hearts were perfused under constant flow, with contractile function monitored by intraventricular balloon. Cardiac uptake of infused [18F]DHE (50–150 kBq.min−1) was monitored by γ-detection, while ROS generation was invoked by menadione infusion (0, 10, or 50 μm), validated by parallel measures of cardiac oxidative stress. Results [18F]DHE was most sensitive to oxidation by superoxide and hydroxyl radicals. Normalised [18F]DHE uptake was significantly greater in menadione-treated hearts (1.44 ± 0.27) versus control (0.81 ± 0.07) (p < 0.05, n = 4/group), associated with concomitant cardiac contractile dysfunction, glutathione depletion, and PKG1α dimerisation. Conclusion [18F]DHE reports on ROS in a validated model of oxidative stress where perfusion (and tracer delivery) is unlikely to impact its pharmacokinetics.


Author(s):  
Soichi Shibuya ◽  
Jessica Allen-Hyttinen ◽  
Paolo De Coppi ◽  
Federica Michielin

Abstract Purpose This paper aims to build upon previous work to definitively establish in vitro models of murine pseudoglandular stage lung development. These can be easily translated to human fetal lung samples to allow the investigation of lung development in physiologic and pathologic conditions. Methods Lungs were harvested from mouse embryos at E12.5 and cultured in three different settings, i.e., whole lung culture, mesenchyme-free epithelium culture, and organoid culture. For the whole lung culture, extracted lungs were embedded in Matrigel and incubated on permeable filters. Separately, distal epithelial tips were isolated by firstly removing mesothelial and mesenchymal cells, and then severing the tips from the airway tubes. These were then cultured either in branch-promoting or self-renewing conditions. Results Cultured whole lungs underwent branching morphogenesis similarly to native lungs. Real-time qPCR analysis demonstrated expression of key genes essential for lung bud formation. The culture condition for epithelial tips was optimized by testing different concentrations of FGF10 and CHIR99021 and evaluating branching formation. The epithelial rudiments in self-renewing conditions formed spherical 3D structures with homogeneous Sox9 expression. Conclusion We report efficient protocols for ex vivo culture systems of pseudoglandular stage mouse embryonic lungs. These models can be applied to human samples and could be useful to paediatric surgeons to investigate normal lung development, understand the pathogenesis of congenital lung diseases, and explore novel therapeutic strategies.


2019 ◽  
Vol 133 (1) ◽  
pp. 117-134 ◽  
Author(s):  
Pamela L. Martín ◽  
Paula Ceccatto ◽  
María V. Razori ◽  
Daniel E.A. Francés ◽  
Sandra M.M. Arriaga ◽  
...  

Abstract We previously demonstrated in in vitro and ex vivo models that physiological concentrations of unconjugated bilirubin (BR) prevent oxidative stress (OS)-induced hepatocanalicular dysfunction and cholestasis. Here, we aimed to ascertain, in the whole rat, whether a similar cholestatic OS injury can be counteracted by heme oxygenase-1 (HO-1) induction that consequently elevates endogenous BR levels. This was achieved through the administration of hemin, an inducer of HO-1, the rate-limiting step in BR generation. We found that BR peaked between 6 and 8 h after hemin administration. During this time period, HO-1 induction fully prevented the pro-oxidant tert-butylhydroperoxide (tBuOOH)-induced drop in bile flow, and in the biliary excretion of bile salts and glutathione, the two main driving forces of bile flow; this was associated with preservation of the membrane localization of their respective canalicular transporters, bile salt export pump (Bsep) and multidrug resistance-associated protein 2 (Mrp2), which are otherwise endocytosed by OS. HO-1 induction counteracted the oxidation of intracellular proteins and membrane lipids induced by tBuOOH, and fully prevented the increase in the oxidized-to-total glutathione (GSHt) ratio, a sensitive parameter of hepatocellular OS. Compensatory elevations of the activity of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) were also prevented. We conclude that in vivo HO-1 induction protects the liver from acute oxidative injury, thus preventing consequent cholestasis. This reveals an important role for the induction of HO-1 and the consequently elevated levels of BR in preserving biliary secretory function under OS conditions, thus representing a novel therapeutic tool to limit the cholestatic injury that bears an oxidative background.


Author(s):  
Rosária Aires ◽  
Ildernandes Vieira-Alves ◽  
Leda Maria Coimbra-Campos ◽  
Marina Ladeira ◽  
Teresa Socarras ◽  
...  

BACKGROUND AND PURPOSE Acute lung injury (ALI) is a critical disorder that has high mortality rates, and pharmacological therapies are so far ineffective. The pathophysiology of ALI involves pulmonary oxidative stress and inflammatory response. Fullerol is a carbon nanocomposite that possesses antioxidant and anti-inflammatory properties. Here, we evaluated the therapeutic potential of fullerol and its mechanisms in a model of paraquat-induced ALI. EXPERIMENTAL APPROACH Rats were divided into ALI (paraquat alone), fullerol (paraquat plus fullerol), and control groups. Survival curves were estimated using the Kaplan-Meier method. The myeloperoxidase assay, ELISA, and hematoxylin and eosin staining were used to determine neutrophils infiltration, cytokines production, and histopathological parameters in lung samples, respectively. The antioxidant effect of fullerol was evaluated in vitro and ex vivo. KEY RESULTS Fullerol (0.01 to 0.3 mg/kg) markedly reduced the severe lung injury and high mortality rates observed in ALI rats. Moreover, fullerol (0.03 mg/kg) inhibited the reactive oxygen species formation and lipid peroxidation seen in lungs from ALI rats, and exhibited a potent concentration-dependent (10 to 10 mg/ml) in vitro antioxidant activity. Importantly, fullerol (0.03 mg/kg) inhibited neutrophils accumulation in bronchoalveolar lavage and lungs, and the increase in pulmonary levels of TNF-α, IL-1β, IL-6, and CINC-1 in ALI rats. CONCLUSIONS AND IMPLICATIONS Fullerol treatment was effective in reducing pulmonary damage and ALI-induced mortality, highlighting its therapeutic potential in an ALI condition. Searching for new pharmacological therapies to treat ALI may be desirable especially in view of the new coronavirus disease 2019 that currently plagues the world.


2021 ◽  
Author(s):  
Charlotte Sarre ◽  
Rafael Contreras Lopez ◽  
Nitirut Nerpernpisooth ◽  
Christian Barrere ◽  
Sarah Bahraoui ◽  
...  

Abstract Background: Mesenchymal Stromal Cells (MSC) have been widely used for their therapeutic properties in many clinical applications including myocardial infarction. Despite promising preclinical results and evidences of safety and efficacy in phases I/ II, inconsistencies in phase III trials have been reported. In a previous study, we have shown using MSC derived from the bone marrow of PPARβ/δ (Peroxisome proliferator-activated receptors β/δ) knockout mice that the acute cardioprotective properties of MSC during the first hour of reperfusion are PPARβ/δ-dependent but not related to the anti-inflammatory effect of MSC. However, the role of the modulation of PPARβ/δ expression on MSC cardioprotective and anti-apoptotic properties has never been investigated. Objectives: The aim of this study was to investigate the role of PPARβ/δ modulation (inhibition or activation) in MSC therapeutic properties in vitro and ex vivo in an experimental model of myocardial infarction.Methods and results: Naïve MSC and MSC pharmacologically activated or inhibited for PPARβ/δ were challenged with H202. Through specific DNA fragmentation quantification and qRT-PCR experiments, we evidenced in vitro an increased resistance to oxidative stress in MSC pre-treated by the PPARβ/δ agonist GW0742 versus naïve MSC. In addition, PPARβ/δ-priming allowed to reveal the anti-apoptotic effect of MSC on co-cultured cardiomyocytes. When injected during reperfusion in an ex vivo heart model of myocardial infarction, PPARβ/δ-primed MSC at a dose of 3.75x105 MSC/heart provided the same cardioprotective efficiency than 7.5x105 naïve MSC, identified as the optimal dose in our model. These enhanced short-term cardioprotective effects were associated with an increase in both anti-apoptotic effects and the number of MSC detected in the left ventricular wall at 1 hour of reperfusion. By contrast, inhibition of PPARβ/δ before their administration in post-ischemic hearts during reperfusion decreased their cardioprotective effects. Conclusion: Altogether these results revealed that PPARβ/δ-primed MSC exhibit an increased resistance to oxidative stress and enhanced anti-apoptotic properties on cardiac cells in vitro. PPARβ/δ-priming appears as an innovative strategy to enhance the cardioprotective effects of MSC and to decrease the injected doses. These results could be of major interest to improve MSC efficacy for the cardioprotection of injured myocardium in AMI patients.


2020 ◽  
Vol 98 (2) ◽  
pp. 85-92 ◽  
Author(s):  
Mihaela Ionica ◽  
Oana M. Aburel ◽  
Adrian Vaduva ◽  
Alexandra Petrus ◽  
Sonia Rațiu ◽  
...  

Obesity is an age-independent, lifestyle-triggered, pandemic disease associated with both endothelial and visceral adipose tissue (VAT) dysfunction leading to cardiometabolic complications mediated via increased oxidative stress and persistent chronic inflammation. The purpose of the present study was to assess the oxidative stress in VAT and vascular samples and the effect of in vitro administration of vitamin D. VAT and mesenteric artery branches were harvested during abdominal surgery performed on patients referred for general surgery (n = 30) that were randomized into two subgroups: nonobese and obese. Serum levels of C-reactive protein (CRP) and vitamin D were measured. Tissue samples were treated or not with the active form of vitamin D: 1,25(OH)2D3 (100 nmol/L, 12 h). The main findings are that in obese patients, (i) a low vitamin D status was associated with increased inflammatory markers and reactive oxygen species generation in VAT and vascular samples and (ii) in vitro incubation with vitamin D alleviated oxidative stress in VAT and vascular preparations and also improved the vascular function. We report here that the serum level of vitamin D is inversely correlated with the magnitude of oxidative stress in the adipose tissue. Ex vivo treatment with active vitamin D mitigated obesity-related oxidative stress.


2015 ◽  
Vol 27 (1) ◽  
pp. 93 ◽  
Author(s):  
D. Laskowski ◽  
Y. Sjunnesson ◽  
R. Båge ◽  
M. A. Sirard ◽  
H. Gustafsson ◽  
...  

Insulin as a key metabolic hormone has crucial functions in metabolic regulation in all mammals. Deviation of its physiological concentration occurs in metabolic disorders as obesity and diabetes in humans or negative energy balance and overfeeding in the cow. As these metabolic disorders are strongly correlated with reproductive disturbances, we investigated the effect of insulin during oocyte maturation on gene expression of bovine Day 8 blastocysts (BC8) by transcriptome analysis. Abattoir-derived oocytes (n = 882) were divided into 3 groups and in vitro matured for 22 h by adding insulin (H: High 10 µg mL–1; L: Low 0.1 µg mL–1 and Z: Zero, control). This was followed by standard in vitro production (IVP) and evaluation of developmental rates up to blastocyst stage. BC8 (n = 120) were pooled in groups of 10 and total RNA was extracted by parallel gDNA and total RNA-extraction (AllPrepDNA/RNA micro kit, cat no. 80284, Qiagen®, Valencia, CA, USA) for analyses of the transcriptome. All samples (4 biological replicates/group) resulted in RIN-values >7.5. RNA amplification, cDNA synthesis, purification, and labelling were performed and 825 ng of Cy3- and Cy5-labelled linearly amplified aRNA was hybridized on the Agilent-manufactured EmbryoGENE-slides in a 2-colour dye swap design. An empirical Bayes moderated t-test was applied to search for the differentially expressed transcripts (DET) between control and insulin-treated groups, using the ‘limma’ package in R (www.r-project.org). The DET were defined as having a 1.5-fold change difference between treatment and control and P < 0.05. Pathways and molecular functions influenced by insulin treatment were analysed by using Ingenuity Pathway Analysis (IPA; Ingenuity® Systems, www.ingenuity.com). As a global pattern, insulin treatment induced an up-regulation of genes. In total, 202 DET in the H and 142 DET in the L group were found where 104 DET were common in both insulin groups. Fifteen selected candidate genes chosen for qPCR validation and 12 (80%) showed similar expression patterns as the microarray data. DET relevant for following cellular functions were found in H: Cell Cycle, Cellular Compromise, Lipid Metabolism, Molecular Transport, Small Molecule Biochemistry respective L: Cell Morphology, Cellular Growth and Proliferation, Cell Cycle, Carbohydrate Metabolism and Cellular Assembly and Organization. The top canonical pathways influenced were Epithelial Adherens Junction Signalling and Remodelling, Germ Cell Sertoli Cell Junction Signalling and NRF2-mediated Oxidative Stress Response. Correlatively, blastocyst rates on Day 8 were significantly lower in H and L v. Z (P < 0.05). The transcriptome data could explain the mechanisms behind the impaired development, as genes involved in cellular growth and energy metabolism in Day 8 blastocysts were affected. The fact that transcripts related to NRF2-mediated oxidative stress response and lipid metabolism are up-regulated suggests that insulin induces dysregulation of cellular functions and energy metabolism leading to impaired embryo developmental potential.Funded by FORMAS.


Sign in / Sign up

Export Citation Format

Share Document