scholarly journals Mechanisms Underlying H2O2-Evoked Carbonyl Modification of Cytoskeletal Protein and Axon Injury in PC-12 Cells

2018 ◽  
Vol 48 (3) ◽  
pp. 1088-1098 ◽  
Author(s):  
Xiejun Zhang ◽  
Zongyang Li ◽  
Qiusheng Zhang ◽  
Lei Chen ◽  
Xianjian Huang ◽  
...  

Background/Aims: To investigate the mechanism that enables oxidative stress and cytoskeleton protein carbonylation to contribute to axonal dysfunction in traumatic brain injury (TBI). Methods: We created an in vitro model of neuronal oxidative damage by exposing a neuron-like cell line (PC-12) to different concentrations (100 μM, 200 μM, and 300 μM) of H2O2 for 24 h or 48 h. Carbonyl modification of cytoskeletal proteins (β-actin and β-tubulin) and its impact on β-actin/β-tubulin filament dynamics were determined by enzyme-linked immunosorbent assay, immunostaining, and western blotting. Depolymerization of β-actin/β-tubulin filaments was evaluated using the monomer/polymer ratio of each protein via western blotting. Phosphorylation of the neurofilament heavy chain (P-NFH) was used as an axonal injury marker and detected by immunostaining. Results: Our results showed that H2O2 treatment led to increased oxidative stress in PC-12 cells, as indicated by the increased generation of malondialdehyde and 8-hydroxydeoxyguanosine and decreased intracellular glutathione levels. H2O2 treatment also increased carbonyl modification of total proteins and cytoskeleton proteins β-actin/β-tubulin, which occurred concurrently with the suppression of proteasome activity. Moreover, H2O2 treatment increased the generation of the axonal injury marker P-NFH, and depolymerization of the β-actin/β-tubulin filaments was indicated by increased monomer/polymer ratios of each protein. Lastly, overexpression of the proteasome β5 subunit in PC-12 cells significantly reduced the H2O2-induced accumulation of carbonylated β-actin/ β-tubulin, P-NFH, and β-actin/β-tubulin depolymerization. Conclusions: We concluded that carbonylation of cytoskeleton proteins could lead to depolymerization of their filaments and axonal injury, and proteasome suppression contributes to the accumulation of carbonylated proteins under oxidative conditions.

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yu Zhang ◽  
Shanxin Liu ◽  
Xiaochun Li ◽  
Jian Ye

Objective. Oxidative damage is a pathological factor that causes cardiovascular damage in the clinic and is increasingly serious. This study focused on the effect of fasudil on H2O2-induced oxidative damage in cardiomyocytes. Materials and Methods. H9C2 cardiomyocytes were cultured in vitro and divided into three groups: control group (Con group), H2O2 treatment (H2O2 group), and fasudil and H2O2 cotreatment (H2O2+fasudil group). The content levels of LDH and MDA in the supernatant were detected, and the morphology of H9C2 cardiomyocytes was observed by light microscopy. 8-OHdG staining was observed by a fluorescence inversion microscope. Cell Counting Kit (CCK-8), western blotting, real-time polymerase chain reaction (RT-PCR), and enzyme-linked immunosorbent assay (ELISA) were used to investigate the effect of fasudil on the Rho/ROCK signaling pathway. Results. Our results showed that after H2O2 treatment, the H9C2 cardiomyocytes were irregular in shape and elliptical. But the morphology of the H2O2+fasudil group was similar to that of the Con group. The green fluorescence of the H2O2 group was significantly enhancer than that of the Con group, while the green fluorescence of the H2O2+fasudil group was weaker than those of the H2O2 group. By detecting the supernatant, it was found that the contents of LDH were significantly increased, and the contents of SOD and CAT in the H2O2 group were significantly decreased. And the expression of antioxidant indicators in the H2O2 group was significantly decreased by western blotting. The results of RT-PCR showed that SOD1 and SOD2 mRNA in the H2O2 group was significantly reduced, and the contents of GPX1 and GPX3 in the H2O2 group were significantly decreased by enzyme-linked immunosorbent assay (ELISA). The expression of ROCK1, ROCK2, and downstream phosphorylation of myosin phosphatase target subunit-1 (p-MYPT-1) was significantly increased in the H2O2 group, while fasudil inhibited the increase of ROCK1, ROCK2, and p-MYPT-1. Conclusions. Fasudil can inhibit the Rho/ROCK signaling pathway induced by H2O2 and reduce oxidative stress response, inhibit apoptosis, and improve antioxidant enzyme activity in H9C2 cardiomyocytes thereby delaying cell senescence.


2021 ◽  
Vol 22 (4) ◽  
pp. 2141
Author(s):  
Srinu Tumpara ◽  
Elena Korenbaum ◽  
Mark Kühnel ◽  
Danny Jonigk ◽  
Beata Olejnicka ◽  
...  

The C-terminal-fragments of alpha1-antitrypsin (AAT) have been identified and their diverse biological roles have been reported in vitro and in vivo. These findings prompted us to develop a monoclonal antibody that specifically recognizes C-36 peptide (corresponding to residues 359–394) resulting from the protease-associated cleavage of AAT. The C-36-targeting mouse monoclonal Immunoglobulin M (IgM) antibody (containing κ light chains, clone C42) was generated and enzyme-linked immunosorbent assay (ELISA)-tested by Davids Biotechnologie GmbH, Germany. Here, we addressed the effectiveness of the novel C42 antibody in different immunoassay formats, such as dot- and Western blotting, confocal laser microscopy, and flow cytometry. According to the dot-blot results, our novel C42 antibody detects the C-36 peptide at a range of 0.1–0.05 µg and shows no cross-reactivity with native, polymerized, or oxidized forms of full-length AAT, the AAT-elastase complex mixture, as well as with shorter C-terminal fragments of AAT. However, the C42 antibody does not detect denatured peptide in SDS-PAGE/Western blotting assays. On the other hand, our C42 antibody, unconjugated as well as conjugated to DyLight488 fluorophore, when applied for immunofluorescence microscopy and flow cytometry assays, specifically detected the C-36 peptide in human blood cells. Altogether, we demonstrate that our novel C42 antibody successfully recognizes the C-36 peptide of AAT in a number of immunoassays and has potential to become an important tool in AAT-related studies.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yongpan Huang ◽  
Xinliang Li ◽  
Xi Zhang ◽  
Jiayu Tang

Oxymatrine (OMT) is the major quinolizidine alkaloid extracted from the root of Sophora flavescens Ait and has been shown to exhibit a diverse range of pharmacological properties. The aim of the present study was to investigate the role of OMT in diabetic brain injury in vivo and in vitro. Diabetic rats were induced by intraperitoneal injection of a single dose of 65 mg/kg streptozotocin (STZ) and fed a high-fat and high-cholesterol diet. Memory function was assessed using a Morris water maze test. A SH-SY5Y cell injury model was induced by incubation with glucose (30 mM/l) to simulate damage in vitro. The serum fasting blood glucose, insulin, serum S100B, malondialdehyde (MDA), and superoxide dismutase (SOD) levels were analyzed using commercial kits. Morphological changes were observed using Nissl staining and electron microscopy. Cell apoptosis was assessed using Hoechst staining and TUNEL staining. NADPH oxidase (NOX) and caspase-3 activities were determined. The effects of NOX2 and NOX4 knockdown were assessed using small interfering RNA. The expression levels of NOX1, NOX2, and NOX4 were detected using reverse transcription-quantitative PCR and western blotting, and the levels of caspase-3 were detected using western blotting. The diabetic rats exhibited significantly increased plasma glucose, insulin, reactive oxygen species (ROS), S-100B, and MDA levels and decreased SOD levels. Memory function was determined by assessing the percentage of time spent in the target quadrant, the number of times the platform was crossed, escape latency, and mean path length and was found to be significantly reduced in the diabetic rats. Hyperglycemia resulted in notable brain injury, including histological changes and apoptosis in the cortex and hippocampus. The expression levels of NOX2 and NOX4 were significantly upregulated at the protein and mRNA levels, and NOX1 expression was not altered in the diabetic rats. NOX and caspase-3 activities were increased, and caspase-3 expression was upregulated in the brain tissue of diabetic rats. OMT treatment dose-dependently reversed behavioral, biochemical, and molecular changes in the diabetic rats. In vitro, high glucose resulted in increases in reactive oxygen species (ROS), MDA levels, apoptosis, and the expressions of NOX2, NOX4, and caspase-3. siRNA-mediated knockdown of NOX2 and NOX4 decreased NOX2 and NOX4 expression levels, respectively, and reduced ROS levels and apoptosis. The results of the present study suggest that OMT alleviates diabetes-associated cognitive decline, oxidative stress, and apoptosis via NOX2 and NOX4 inhibition.


2019 ◽  
Vol 149 (12) ◽  
pp. 2191-2198
Author(s):  
Joan Campo-Sabariz ◽  
David Moral-Anter ◽  
M Teresa Brufau ◽  
Mickael Briens ◽  
Eric Pinloche ◽  
...  

ABSTRACT Background Selenium (Se) participates in different functions in humans and other animals through its incorporation into selenoproteins as selenocysteine. Inadequate dietary Se is considered a risk factor for several chronic diseases associated with oxidative stress. Objective The role of 2-hydroxy-(4-methylseleno)butanoic acid (HMSeBA), an organic form of Se used in animal nutrition, in supporting selenoprotein synthesis and protecting against oxidative stress was investigated in an in vitro model of intestinal Caco-2 cells. Methods Glutathione peroxidase (GPX) and thioredoxin reductase (TXNRD) activities, selenoprotein P1 protein (SELENOP) and gene (SELENOP) expression, and GPX1 and GPX2 gene expression were studied in Se-deprived (FBS removal) and further HMSeBA-supplemented (0.1–625 μM, 72 h) cultures. The effect of HMSeBA supplementation (12.5 and 625 μM, 24 h) on oxidative stress induced by H2O2 (1 mM) was evaluated by the production of reactive oxygen species (ROS), 4-hydroxy-2-nonenal (4-HNE) adducts, and protein carbonyl residues compared with a sodium selenite control (SS, 5 μM). Results Se deprivation induced a reduction (P < 0.05) in GPX activity (62%), GPX1 expression, and both SELENOP (33%) and SELENOP expression. In contrast, an increase (P < 0.05) in GPX2 expression and no effect in TXNRD activity (P = 0.09) were observed. HMSeBA supplementation increased (P < 0.05) GPX activity (12.5–625 μM, 1.68–1.82-fold) and SELENOP protein expression (250 and 625 μM, 1.87- and 2.04-fold). Moreover, HMSeBA supplementation increased (P < 0.05) GPX1 (12.5 and 625 μM), GPX2 (625 μM), and SELENOP (12.5 and 625 μM) expression. HMSeBA (625 μM) was capable of decreasing (P < 0.05) ROS (32%), 4-HNE adduct (49%), and protein carbonyl residue (75%) production after H2O2 treatment. Conclusion Caco-2 cells can use HMSeBA as an Se source for selenoprotein synthesis, resulting in protection against oxidative stress.


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.


Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 59
Author(s):  
Yeon-Seop Jung ◽  
So-Hee Lee ◽  
So Young Chun ◽  
Dae Hwan Kim ◽  
Byung Ik Jang ◽  
...  

Excessive oxidative stress plays a role in hepatotoxicity and the pathogenesis of hepatic diseases. In our previous study, the phenolic extract of beluga lentil (BLE) showed the most potent in vitro antioxidant activity among extracts of four common varieties of lentils; thus, we hypothesized that BLE might protect liver cells against oxidative stress-induced cytotoxicity. BLE was evaluated for its protective effects against oxidative stress-induced hepatotoxicity in AML12 mouse hepatocytes and BALB/c mice. H2O2 treatment caused a marked decrease in cell viability; however, pretreatment with BLE (25–100 μg/mL) for 24 h significantly preserved the viability of H2O2-treated cells up to about 50% at 100 μg/mL. As expected, BLE dramatically reduced intracellular reactive oxygen species (ROS) levels in a dose-dependent manner in H2O2-treated cells. Further mechanistic studies demonstrated that BLE reduced cellular ROS levels, partly by increasing expression of antioxidant genes. Furthermore, pretreatment with BLE (400 mg/kg) for 2 weeks significantly reduced serum levels of alanine transaminase and triglyceride by about 49% and 40%, respectively, and increased the expression and activity of glutathione peroxidase in CCl4-treated BALB/c mice. These results suggest that BLE protects liver cells against oxidative stress, partly by inducing cellular antioxidant system; thus, it represents a potential source of nutraceuticals with hepatoprotective effects.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jing Wang ◽  
Wei Zhang ◽  
Sixin Wang ◽  
Yamin Wang ◽  
Xu Chu ◽  
...  

Probiotics are widely used for protection against stress-induced intestinal dysfunction. Oxidative stress plays a critical role in gastrointestinal disorders. It is established that probiotics alleviate oxidative stress; however, the mechanism of action has not been elucidated. We developed an in vitro intestinal porcine epithelial cells (IPEC-J2) model of oxidative stress to explore the antioxidant effect and potential mode of action of Lactobacillus plantarum ZLP001. The IPEC-J2 cells were preincubated with and without L. plantarum ZLP001 for 3 h and then exposed to hydrogen peroxide (H2O2) for 4 h. Pretreatment with L. plantarum ZLP001 protected IPEC-J2 cells against H2O2-induced oxidative damage as indicated by cell viability assays and significantly alleviated apoptosis elicited by H2O2. L. plantarum ZLP001 pretreatment decreased reactive oxygen species production and the cellular malondialdehyde concentration and increased the mitochondrial membrane potential compared with H2O2 treatment alone, suggesting that L. plantarum ZLP001 promotes the maintenance of redox homeostasis in the cells. Furthermore, L. plantarum ZLP001 regulated the expression and generation of some antioxidant enzymes, thereby activating the antioxidant defense system. Treatment with L. plantarum ZLP001 led to nuclear erythroid 2-related factor 2 (Nrf2) enrichment in the nucleus compared with H2O2 treatment alone. Knockdown of Nrf2 significantly weakened the alleviating effect of L. plantarum ZLP001 on antioxidant stress in IPEC-J2 cells, suggesting that Nrf2 is involved in the antioxidative effect of L. plantarum ZLP001. Collectively, these results indicate that L. plantarum ZLP001 is a promising probiotic bacterium that can potentially alleviate oxidative stress.


2020 ◽  
Vol 40 (1) ◽  
pp. 25-34
Author(s):  
A Beklen ◽  
D Uckan

Information on the effects of propylene glycol (PG) and vegetable glycerin (VG) and on cytotoxicity and subsequent activation of the biological mediators is limited in periodontal diseases. This study analyzes the effect of unflavored PG/VG alone or in combination with nicotine on gingival epithelial cells. The cells were exposed to different PG/VG (± nicotine) concentrations for 24 h and cytotoxicity was evaluated by calorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromid assay. The expressions of interleukin (IL)-6, IL-8, and matrix metalloproteinases (MMPs)-9 were measured using an enzyme-linked immunosorbent assay and a western blotting. Stimulation with PG/VG mixtures reduced cell viability compared to nonexposed controls ( p < 0.05). Adding PG/VG increased the levels of IL-6, IL-8, and MMP-9, and the amount of PG had more biological impact compared to the VG amount. The nicotine augmented this effect compared to its nicotine-free counterparts. In western blotting result, MMP-9 was clearly activated in almost all samples. These findings suggest that the main constituents PG/VG are cytotoxic and able to induce biological response in gingival cells in vitro. Despite being advertised as less harmful than conventional cigarettes, electronic cigarette liquid pose certain risks on periodontal cells. Awareness about the effects of electronic cigarettes on periodontal diseases must be increased.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Bonggi Lee ◽  
Kyoung Mi Moon ◽  
Seong Jin Kim ◽  
So Hee Kim ◽  
Dae Hyun Kim ◽  
...  

Background. Uncontrolled melanogenesis and wrinkle formation are an indication of photoaging. Our previous studies demonstrated that (Z)-5-(2,4-dihydroxybenzylidene)thiazolidine-2,4-dione (MHY498) inhibited tyrosinase activity and melanogenesisin vitro.Objective. To examinein vivoeffects of MHY498 as an antiaging compound on UVB-induced melanogenesis and wrinkle formation, we topically applied MHY498 on dorsal skin of HRM-2 hairless mice.Methods. Using histological analysis, we evaluated effects of MHY498 on melanogenesis and wrinkle formation after UVB exposure. In addition, related molecular signaling pathways were examined using western blotting, fluorometric assay, and enzyme-linked immunosorbent assay.Results. MHY498 suppressed UVB-induced melanogenesis by inhibiting phosphorylation of CREB and translocation of MITF protein into the nucleus, which are key factors for tyrosinase expression. Consistently, tyrosinase protein levels were notably reduced in the dorsal skin of the hairless mice by MHY498 treatment. Furthermore, MHY498 inhibited UVB-induced wrinkle formation and collagen fiber destruction by increasing type 1 procollagen concentration and decreasing protein expression levels of MMPs, which play an essential role in collagen fiber degradation. As a mechanism, MHY498 notably ameliorated UVB-induced oxidative stress and NF-κB activation in the dermal skin of the hairless mice.Conclusion. Our study suggests that MHY498 can be used as a therapeutic or cosmetic agent for preventing uncontrolled melanogenesis and wrinkle formation.


2021 ◽  
Vol 64 (2) ◽  
pp. 335-343
Author(s):  
Zhaojin Luan ◽  
Xiaomei Fan ◽  
Yongchao Zhao ◽  
Huizi Song ◽  
Wei Du ◽  
...  

Abstract. Trehalose, a naturally nontoxic disaccharide that does not exist in mammals, stabilizes cell membrane integrity under oxidative stress conditions, the mechanism of which is still unclear. Here, we analyzed the effects of trehalose on sheep epididymis epithelial cell (EEC) proliferation and its possible mechanisms. To study the effect of trehalose on EECs, EECs were isolated from testes of 12-month-old sheep; cell counting kit-8 (CCK-8) was used to measure the growth of the cells. Cell proliferation was evaluated by assaying cell cycle and apoptosis, and RT-PCR was utilized to identify the epididymal molecular markers glutathione peroxidase 5 (GPX5) and androgen receptor (AR). Next, reactive oxygen species (ROS) content was evaluated by a dichloro-dihydro-fluorescein diacetate (DCFH-DA) probe. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were evaluated by enzyme chemistry methods, and GPX5 expression was evaluated by qRT-PCR and enzyme-linked immunosorbent assay (ELISA). The results showed that 100 mM trehalose significantly improved the proliferation potential of EECs, in which the cells could be serially passaged 14 times with continued normal GPX5 and AR marker gene expression in vitro. The trehalose can increase significantly a proportion of EECs in S phase (P<0.01) and decrease significantly the apoptotic rate of EECs (P<0.01) compared to the control. Moreover, the trehalose decreased ROS significantly (P<0.01) and increased CAT (P<0.01) and GSH-Px (P<0.05) activities significantly in EECs. GPX5 mRNA and protein expression were also significantly upregulated in trehalose-treated EECs (P<0.05 and P<0.01 respectively). Our study suggested that exogenous trehalose exhibited antioxidant activity through increasing the activities of CAT, GSH-Px, and the expression level of GPX5 and could be employed to maintain vitality of sheep EECs during long-term in vitro culture.


Sign in / Sign up

Export Citation Format

Share Document