scholarly journals Investigation of sphingosin-1-phosphate-triggered matriptase activation using a rat primary hepatocyte model

2019 ◽  
Vol 67 (4) ◽  
pp. 578-587
Author(s):  
Réka Fanni Barna ◽  
Judit Mercédesz Pomothy ◽  
Zsuzsanna Paréj ◽  
Erzsébet Pásztiné Gere

Sphingosine-1-phosphate (S1P) has been reported as a matriptase activator. The aim of this study was to reveal if S1P can influence hepcidin production. Furthermore, we investigated how S1P can affect the viability and the redox status of primary hepatocytes. Rat primary hepatocytes were cultivated for 72 h and were treated with 50, 200, 1000 ng/ml S1P. Cell-free supernatants were collected every 24 h. Cell viability was tested by a colorimetric method using tetrazolium compound (MTS). The hepcidin levels in the cell-free supernatants were examined with hepcidin sandwich ELISA to determine the effect of S1P on the hepcidin-modulating ability of matriptase. In order to estimate the extent of S1P-generated oxidative stress, extracellular H2O2 measurements were performed by the use of fluorescent dye. Based on the findings, S1P treatment did not cause cell death for 72 h at concentrations up to 1000 ng/ml. S1P did not influence the extracellular H2O2 production for 72 h. The hepcidin levels were significantly suppressed in hepatocytes exposed to S1P treatment. Further studies would be needed to explore the exact mechanism of action of S1P.

Antioxidants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 16 ◽  
Author(s):  
Flávia Póvoa da Costa ◽  
Bruna Puty ◽  
Lygia S. Nogueira ◽  
Geovanni Pereira Mitre ◽  
Sávio Monteiro dos Santos ◽  
...  

Piceatannol is a resveratrol metabolite that is considered a potent antioxidant and cytoprotector because of its high capacity to chelate/sequester reactive oxygen species. In pathogenesis of periodontal diseases, the imbalance of reactive oxygen species is closely related to the disorder in the cells and may cause changes in cellular metabolism and mitochondrial activity, which is implicated in oxidative stress status or even in cell death. In this way, this study aimed to evaluate piceatannol as cytoprotector in culture of human periodontal ligament fibroblasts through in vitro analyses of cell viability and oxidative stress parameters after oxidative stress induced as an injury simulator. Fibroblasts were seeded and divided into the following study groups: control, vehicle, control piceatannol, H2O2 exposure, and H2O2 exposure combined with the maintenance in piceatannol ranging from 0.1 to 20 μM. The parameters analyzed following exposure were cell viability by trypan blue exclusion test, general metabolism status by the 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method, mitochondrial activity through the ATP production, total antioxidant capacity, and reduced gluthatione. Piceatannol was shown to be cytoprotective due the maintenance of cell viability between 1 and 10 μM even in the presence of H2O2. In a concentration of 0.1 μM piceatannol decreased significantly cell viability but increased cellular metabolism and antioxidant capacity of the fibroblasts. On the other hand, the fibroblasts treated with piceatannol at 1 μM presented low metabolism and antioxidant capacity. However, piceatannol did not protect cells from mitochondrial damage as measured by ATP production. In summary, piceatannol is a potent antioxidant in low concentrations with cytoprotective capacity, but it does not prevent all damage caused by hydrogen peroxide.


2019 ◽  
Vol 8 (5) ◽  
pp. 641-653 ◽  
Author(s):  
Jinbao Gao ◽  
Yunjun Li ◽  
Wende Li ◽  
Haijiang Wang

Abstract Neuronal death caused by inflammatory cytokine-mediated neuroinflammation is being extensively explored. Thioredoxin reductase (TrxR) 2 is a novel mediator of inflammation response. In the current study, we focus on the mechanisms of TrxR2 overexpression in inflammation-mediated neuronal death. LPS was used to induce neuroinflammation in N2a cells in vitro. Adenovirus-loaded TrxR2 was transfected into N2a cells to up-regulate TrxR2 expression. Then, cell viability was determined via MTT assay and TUNEL assay. Apoptosis was measured via western blotting and ELISA. Oxidative stress was detected via ELISA and flow cytometry. A pathway inhibitor was used to verify the role of the Akt–Parkin pathway in the LPS-mediated N2a cell death in the presence of TrxR2 overexpression. With the help of immunofluorescence assay and western blotting, we found that TrxR2 expression was significantly reduced in response to LPS treatment, and this effect was associated with N2a cell death via apoptosis. At the molecular level, TrxR2 overexpression elevated the activity of the Akt–Parkin pathway, as evidenced by the increased expression of p-Akt and Parkin. Interestingly, inhibition of the Akt–Parkin pathway abolished the regulatory effect of TrxR2 on LPS-treated N2a cells, as evidenced by the decreased cell viability and increased apoptotic ratio. Besides, TrxR2 overexpression also reduced oxidative stress, inflammation factor transcription and mitochondrial apoptosis. However, inhibition of Akt–Parkin axis abrogated the protective effects of TrxR2 on redox balance, mitochondrial performance and cell survival. LPS-mediated neuronal death was linked to a drop in TrxR2 overexpression and the inactivation of the Akt–Parkin pathway. Overexpression of TrxR2 sustained mitochondrial function, inhibited oxidative stress, repressed inflammation response, and blocked mitochondrial apoptosis, finally sending a pro-survival signal for the N2a cells in the setting of LPS-mediated inflammation environment.


2019 ◽  
Vol 20 (11) ◽  
pp. 2723 ◽  
Author(s):  
Giuseppe Antonio Malfa ◽  
Barbara Tomasello ◽  
Rosaria Acquaviva ◽  
Carlo Genovese ◽  
Alfonsina La Mantia ◽  
...  

Betula etnensis Raf. (Birch Etna) belonging to the Betulaceae family grows on the eastern slope of Etna. Many bioactive compounds present in Betula species are considered promising anticancer agents. In this study, we evaluated the effects of B. etnensis Raf. bark methanolic extract on a human colon cancer cell line (CaCo2). In order to elucidate the mechanisms of action of the extract, cellular redox status, cell cycle, and heme oxygenase-1 (HO-1) expression in ferroptosis induction were evaluated. Cell viability and proliferation were tested by tetrazolium (MTT) assayand cell cycle analysis, while cell death was evaluated by annexin V test and lactic dehydrogenase (LDH) release. Cellular redox status was assessed by measuring thiol groups (RSH) content, reactive oxygen species (ROS) production, lipid hydroperoxide (LOOH) levels and (γ-glutamylcysteine synthetase) γ-GCS and HO-1 expressions. The extract significantly reduced cell viability of CaCo2, inducing necrotic cell death in a concentration-depending manner. In addition, an increase in ROS levels and a decrease of RSH content without modulation in γ-GCS expression were detected, with an augmentation in LOOH levels and drastic increase in HO-1 expression. These results suggest that the B. etnensis Raf. extract promotes an oxidative cellular microenvironment resulting in CaCo2 cell death by ferroptosis mediated by HO-1 hyper-expression.


2020 ◽  
pp. 27-33
Author(s):  
Ahmet Sevki Taskiran ◽  
Merve Ergul

Background. Recent studies have shown that oxytocin plays a vital role in neurons and glial cells. However, its effect on hydrogen peroxide (H2O2)-induced oxidative stress as well as cyclooxygenase-1 (COX-1) and COX-2 in glial cells are still unclear. Objective. This study aims to examine the effect of oxytocin on glial cell viability, oxidative stress, COX-1, and COX-2 in C6 glial cells after exposure to H2O2. Methods. In this study, C6 glioma cell line was used to study the effect of oxytocin on the glial cell in four cell groups. The control group was untreated. Cells in the H2O2 group were treated with 0.5 mM H2O2 for 24 h. Cells in the oxytocin group were treated with various concentrations (0.25, 0.5, 1, and 2 μg/mL) of oxytocin for 24 h. Cells in the oxytocin+H2O2 group were pre-treated with various concentrations (0.25, 0.5, 1, and 2 μg/mL) of oxytocin for 1 h before 24-h exposure to 0.5 mM H2O2. Cell viability was evaluated using XTT assay. Total antioxidant status and total oxidant status (TOS), COX-1, and COX-2 levels in the cells were measured by commercial kits. Results. Oxytocin with various concentrations significantly decreased the viability of C6 cells after H2O2-induced oxidative stress (P < 0.01). It also significantly increased the levels of TOS, COX-1, and COX-2 in C6 cells after H2O2-induced oxidative stress (P < 0.001). Conclusion. Oxytocin increases glial cell death after H2O2-induced oxidative damage in C6 cells, along with upregulation of COX-1 and COX-2 levels.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Eriko Sugano ◽  
Namie Murayama ◽  
Maki Takahashi ◽  
Kitako Tabata ◽  
Makoto Tamai ◽  
...  

The retina is constantly subjected to oxidative stress, which is countered by potent antioxidative systems present in retinal pigment epithelial (RPE) cells. Disruption of these systems leads to the development of age-related macular degeneration. Thioredoxin 2 (Trx2) is a potent antioxidant, which acts directly on mitochondria. In the present study, oxidative stress was induced in the human RPE cell line (ARPE-19) using 4-hydroxynonenal (4-HNE) or C2-ceramide. The protective effect of Trx2 against oxidative stress was investigated by assessing cell viability, the kinetics of cell death, mitochondrial metabolic activity, and expression of heat shock proteins (Hsps) in Trx2-overexpressing cell lines generated by transfecting ARPE cells with an adeno-associated virus vector encoding Trx2. We show that overexpression of Trx2 reduced cell death induced by both agents when they were present in low concentrations. Moreover, early after the induction of oxidative stress Trx2 played a key role in the maintenance of the cell viability through upregulation of mitochondrial metabolic activity and inhibition of Hsp70 expression.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Caiyun Huang ◽  
Zijuan Fan ◽  
Dandan Han ◽  
Lee J. Johnston ◽  
Xi Ma ◽  
...  

Abstract Background Oxidative stress is a main cause of piglet gut damage and diarrhea. Pyrroloquinoline quinone (PQQ), is a novel redox cofactor with antioxidant properties. However, the effect and mechanism that PQQ supplementation decreases oxidative injury in weaned pigs is not understood. Therefore, the aim of this study is to confirm the effect of PQQ on regulating redox status in weaned pigs and the mechanism for antioxidant function by porcine intestinal epithelial cell line (IPEC-J2) challenged with H2O2. Results Experiment 1, 144 Duroc × Landrace × Yorkshire pigs (weaned at 28 d) were allocated to four groups: received a basal diet (control) and diets supplemented with 0.15%, 0.30% and 0.45% PQQ, respectively. On d 28, growth performance, diarrhea incidence and redox factors were measured. Experiment 2, IPEC-J2 were treated with or without PQQ in the presence or absence of H2O2 for indicated time points. Experiment 3, IPEC-J2 were transfected with or without Nrf2 siRNA, then treated according to Experiment 2. The cell viability, redox factors, protein of tight junctions and Nrf2 pathway were determined. In vivo, PQQ supplementation demonstrated dose-related improvements in average daily gain, and gain to feed ratio (Linear P < 0.05). During d 0–28, compared to controls, 0.45% PQQ supplementation for pigs decreased diarrhea incidence and MDA content in liver and jejunum, and increased concentration of SOD in liver; 0.3% PQQ supplementation decreased ileal and liver MDA concentration; and 0.15% PQQ supplementation decreased ileal MDA concentration (P < 0.05). In vitro, compared to cells cultured with H2O2, pre-treatment with PQQ increased cell viability, tight junction proteins expression including ZO-1, ZO-2, Occludin and Claudin-1; and decreased ROS concentration and level of Caspase-3 (P < 0.05); as well as upregulated the ratio of Bcl-2 to Bax and protein expression of nuclear Nrf2, HO-1. Notably, Nrf2 knockdown by transfection with Nrf2 siRNA largely abrogated the positive effects of PQQ pretreatment on H2O2-induced intracellular changes. Conclusions PQQ administration attenuated oxidative stress in weaned pigs which is associated with activation of Nrf2/HO-1 pathway.


Author(s):  
Tong Xing ◽  
Xiangxing Chen ◽  
Jiaolong Li ◽  
Lin Zhang ◽  
Feng Gao

Abstract Oxidative stress seriously affects poultry production. Nutritional manipulations have been effectively used to alleviate the negative effects caused by oxidative stress. This study investigated the attenuating effects and potential mechanisms of dietary taurine on growth performance and meat quality of broiler chickens challenged with hydrogen peroxide (H2O2). Briefly, a total of 192 male Arbor Acres broilers (28-day-old) were randomly categorized into 3 groups: non-injection of birds on basal diets (control), 10.0% H2O2-injection of birds on basal diets (H2O2), and 10.0% H2O2-injection of birds on basal diets supplemented with 5 g/kg taurine (H2O2+taurine). Each group consisted of 8 cages of 8 birds each. Results indicated that H2O2 administration significantly reduced growth performance and impaired breast meat quality by decreasing ultimate pH and increasing shear force value (P &lt; 0.05). Dietary taurine improved the body weight gain and feed intake, and decreased feed/gain ratio of H2O2-challenged broilers. Meanwhile, oxidative stress induced by intraperitoneal injection of H2O2 suppressed the nuclear factor-κB (NF-κB) signaling and initiated autophagy and apoptosis. Compared with the H2O2 group, taurine supplementation restored the redox status in breast muscle by decreasing levels of reactive oxygen species and contents of oxidative products and increasing antioxidant capacity (P &lt; 0.05). Moreover, upregulated mRNA expression of NF-κB signaling-related genes including p50 and Bcl-2, as well as enhanced protein expression of NF-κB were observed in the H2O2+taurine group (P &lt; 0.05). Additionally, dietary taurine decreased expression of caspase family, beclin-1 and LC3-II (P &lt; 0.05), thereby rescuing autophagy and apoptosis in breast muscle induced by H2O2. Collectively, dietary supplementation with taurine effectively improves growth performance and breast meat quality of broilers challenged with H2O2, possibly by protecting against oxidative injury and modulating cell death signaling.


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