Expression Levels Of Superoxide Dismutase Research Articles

Daidzein Has Anti-Oxidant Activity in Normal Human Kidney Tubular HK-2 Cells via FOXO3/SOD2 Pathway

The anti-oxidant activity of daidzein was accessed by checking the expression level of superoxide dismutase 2 (SOD2) in HK-2 cell, a kidney proximal tubular cell line. SOD2 expression was increased in HK-2 cells treated by daidzein with a dose and time-dependent manner. Daidzein reduced the reactive oxygen species (ROS) level (about 60% compared to DMSO control with p = 0.005) in HK-2 cells. Daidzein caused FOXO3 to be translocated from cytosol into nucleus. Down-regulation of FOXO3 by transfection of siRNA against FOXO3 attenuated the expression of SOD2 and ROS level (p = 0.006) by daidzein. Taken together, this study has shown that daidzein displays anti-oxidant activity in HK-2 kidney proximal tubular cell line through up-regulation of FOXO3/SOD2 signaling pathway.

Dietary optimal reduced glutathione improves innate immunity, oxidative stress resistance and detoxification function of grass carp (Ctenopharyngodon idella) against microcystin-LR

The present study reports on the effects of dietary glutathione (GSH) on non-specific immunity, oxidative stress resistance and detoxification in grass carp (Ctenopharyngodon idella) infected with microcystins. Six hundred and thirty juvenile grass carp with initial body weight of (5.10 ± 0.09) g were randomly distributed into six groups with three replicates each and stocked in 18 tanks (35 fish per tank), fed six diets containing graded levels of GSH for 60 days. At the end of the feeding trial, ten fish per tank were selected and injected intraperitoneally with 200 μg/kg body weight (BW) dose of pure microcystin-LR (MC-LR). The results showed that, at 0 h, 24 h of MC-LR injection, with the increase of dietary GSH content, serum lysozyme, alkaline phosphatase (ALP) and complement 3 (C3) levels, the activities and mRNA expression levels of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) in liver, and liver GSH content increased first and then decreased (P < 0.05). When dietary GSH content was 407.45 mg/kg diet, these parameters reached the highest levels (P < 0.05), and in the same dose of GSH group, in addition to lysozyme activity at 24 h was significantly higher than that at 0 h, the other indicators at 24 h were significantly lower than those before exposure (at 0 h) (P < 0.05). In contrast, serum cortisol and glucose, and liver reactive oxygen species (ROS) and malondialdehyde (MDA) contents decreased first and then increased (P < 0.05), when dietary GSH content was 407.45 mg/kg diet, the above parameters reached the lowest levels (P < 0.05), and in the same dose of GSH group their contents at 24 h were significantly higher than those before exposure (P < 0.05). In addition, before MC-LR exposure, the activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) had no significant difference of all groups (P > 0.05), liver glutathione S-transferase (GST) and its mRNA expression levels had a rising trend while liver glutathione reductase (GR) activities significantly decreased and then maintained a lower level with dietary GSH content increasing (P < 0.05). At 24 h of MC-LR injection, serum ALT and AST activities decreased at first and then increased while liver GST and GR activities and their mRNA expression levels increased first and then decreased (P < 0.05). Therefore, the basal diet supplemented with GSH 407.45 mg/kg could improve innate immunity, antioxidant stress ability and detoxification function of grass carp against MC-LR exposure. However, dietary excess GSH might promote oxidation, resulting in negative effect.

Herbicides diuron and fluazifop-p-butyl affect avoidance response and multixenobiotic resistance activity in earthworm Eisenia andrei

The usage of pesticides has been steadily increasing over the last decades, and among them herbicides are the most commonly used ones. Despite their main mode of action targeting plant organisms, they can also have adverse effects on non-target animal organisms. In soil ecosystems, earthworms play an important role due to their positive impacts on the soil functioning and they represent good model organisms in soil ecotoxicology. The aim of the present study was to assess the effects of two herbicides on several endpoints at different levels of biological organization in the earthworm Eisenia andrei. Diuron and fluazifop-p-butyl were selected for the investigation and their lethal concentrations were determined: LC50 48 h: 89.087 μg/cm2 for diuron and 6.167 μg/cm2 for fluazifop-p-butyl. Furthermore, measurements of enzymatic biomarkers (catalase (CAT), acetylcholinesterase (AChE), carboxylesterase (CES) and glutathione S-transferase (GST)), multixenobiotic resistance (MXR) activity and gene expression of antioxidative enzymes (only for fluazifop-p-butyl) were conducted. Enzymatic biomarker responses showed no significant differences compared to the control after the exposure to the investigated herbicides, whereas the MXR activity was significantly inhibited. The gene expression level of superoxide dismutase (sod) and glutathione S-transferase (gst) after fluazifop-p-butyl exposure showed a significant increase. Finally, avoidance behavior in soil was assessed and it was determined that both herbicides caused significant avoidance response. The obtained results show that both investigated herbicides significantly affect earthworms on different levels of biological organization. This emphasizes the importance of comprehensive ecotoxicological assessment of herbicide effects on non-target organisms at all organizational levels.

Tanshinone IIA improves hypoxic ischemic encephalopathy through TLR‑4‑mediated NF‑κB signal pathway.

Hypoxic ischemic encephalopathy (HIE) is the most common brain injury following hypoxia and/or ischemia caused by various factors during the perinatal period, resulting in detrimental neurological deficits in the nervous system. Tanshinone IIA (Tan-IIA) is a potential agent for the treatment of cardiovascular and cerebrovascular diseases. In this study, the efficacy of Tan-IIA was investigated in a newborn mouse model of HIE. The dynamic mechanism of Tan-IIA was also investigated in the central nervous system of neonate mice. Intravenous injection of Tan-IIA (5 mg/kg) was administered and changes in oxidative stress, inflammation and apoptosis-associated proteins in neurons. Histology and immunohistochemistry was used to determine infarct volume and the number of damaged neurons by Fluoro-Jade C staining. The effects of Tan-IIA on mice with HIE were evaluated by body weight, brain water content, neurobehavioral tests and blood-brain barrier permeability. The results demonstrated that the apoptosis rate was decreased following Tan-IIA administration. Expression levels of pro-apoptotic proteins, caspase-3 and caspase-9 and P53 were downregulated. Expression of Bcl-2 anti-apoptotic proteins was upregulated by Tan-IIA treatment in neuro. Results also found that Tan-IIA treatment decreased production of inflammatory cytokines such as interleukin-1, tumor necrosis factor-α, C-X-C motif chemokine 10, and chemokine (C-C motif) ligand 12. Oxidative stress was also reduced by Tan-IIA in neurons, as determined by the expression levels of superoxide dismutase, glutathione and catalase, and the production of reactive oxygen species. The results demonstrated that Tan-IIA treatment reduced the infarct volume and the number of damaged neurons. Furthermore, body weight, brain water content and blood-brain barrier permeability were markedly improved by Tan-IIA treatment of newborn mice following HIE. Furthermore, the results indicated that Tan-IIA decreased Toll-like receptor-4 (TLR-4) and nuclear factor-κB (NF-κB) expression in neurons. TLR-4 treatment of neuronal cell in vitro addition stimulated NF-κB activity, and further enhanced the production of inflammatory cytokines and oxidative stress levels in neurons. In conclusion, these results suggest that Tan-IIA treatment is beneficial for improvement of HIE through TLR-4-mediated NF-κB signaling.

Simvastatin Inhibits Activation of NADPH Oxidase/p38 MAPK Pathway and Enhances Expression of Antioxidant Protein in Parkinson Disease Models.

Evidence suggests that oxidative stress is involved in the pathogenesis of Parkinson disease (PD). Simvastatin has been suggested to protect against oxidative stress in several diseases. However, the molecular mechanisms by which simvastatin protects against neuropathology and oxidative damage in PD are poorly elucidated. In this study, we aimed to investigate the potential neuroprotective effects of simvastatin owing to its anti-oxidative properties in 6-hydroxydopamine (6-OHDA)-treated SH-SY5Y cells and mice. The results of 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence and CCK-8 assay demonstrated that simvastatin reduced intracellular reactive oxygen species (ROS) levels and reversed apoptosis in 6-OHDA-treated SH-SY5Y cells. Mechanistic studies revealed that 6-OHDA-induced activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase/p38 mitogen-activated protein kinase (MAPK) pathway was inhibited and nuclear factor-κB (NF-κB) nuclear transcription decreased in SH-SY5Y cells after simvastatin treatment. Enhanced expression levels of superoxide dismutase (SOD), heme oxygenase-1 (HO-1), peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) and glutamate-cysteine ligase modifier subunit (GCLM) were observed after simvastatin treatment in 6-OHDA-treated SH-SY5Y cells. In vivo studies revealed that administration of simvastatin by gavage decreased limb-use asymmetry and apomorphine-induced rotations in 6-OHDA-lesioned mice. Simvastatin increased dopaminergic neurons and reduced protein tyrosine nitration and gliosis in the midbrain of PD mice. An inhibitory effect on activation of the NADPH oxidase/p38 MAPK was observed, and increased antioxidant protein expression in the midbrain were seen in the simvastatin plus 6-OHDA group compared with the 6-OHDA-lesioned group. Taken together, these results demonstrate that simvastatin might inhibit the activation of NADPH oxidase/p38 MAPK pathway, enhance antioxidant protein expression and protect against oxidative stress, thereby providing a novel antioxidant mechanism that has therapeutic validity.

Oxidative Stress and Aberrant Programmed Cell Death Are Associated With Pollen Abortion in Isonuclear Alloplasmic Male-Sterile Wheat.

Cytoplasmic male sterility is crucial for the utilization of hybrid heterosis and it possibly occurs in parallel with tapetal programmed cell death (PCD) and oxidative metabolism responses. However, little is known about the mechanisms that underlie pollen abortion in wheat. Therefore, we obtained two isonuclear alloplasmic male sterile lines (IAMSLs) with Aegilops kotschyi and Ae. juvenalis cytoplasm. Compared with the maintainer line, cytochemical analyses of the anthers demonstrated that the IAMSLs exhibited anomalous tapetal PCD and organelles, with premature PCD in K87B1-706A and delayed PCD in Ju87B1-706A. We also found that the dynamic trends in reactive oxygen species (ROS) were consistent in these two IAMSLs during anther development and they were potentially associated with the initiation of tapetal PCD. In addition, the activities of ROS-scavenging enzymes increased rapidly, whereas non-enzymatic antioxidants were downregulated together with excess ROS production in IAMSLs. Real-time PCR analysis showed that the expression levels of superoxide dismutase, catalase, and ascorbate peroxidase genes, which encode important antioxidant enzymes, were significantly upregulated during early pollen development. Thus, we inferred that excessive ROS and the abnormal transcript levels of antioxidant enzyme genes disrupted the balance of the antioxidant system and the presence of excess ROS may have been related to aberrant tapetal PCD progression, thereby affecting the development of microspores and ultimately causing male sterility. These relationships between the mechanism of PCD and ROS metabolism provide new insights into the mechanisms responsible for abortive pollen in wheat.

Methyl ferulic acid exerts anti-apoptotic effects on L-02 cells via the ROS-mediated signaling pathway.

The present study aimed to investigate the anti-apoptotic effects of methyl ferulic acid (MFA) on L-02 cell apoptosis induced by ethanol, and to elucidate the possible underlying mechanisms. L-02 cells were examined after being soaked in ethanol (400mM) to allow the ethanol to permeate into the cells for 24h. Cell survival was measured by MTT assay. Cell apoptosis was assessed by both flow cytometry and single-stranded DNA assays. Intracellular reactive oxygen species(ROS) production was determined using the 2',7'-dichlorofluorescein-diacetate dye. The protein expression levels of p38, p-p38, JNK, p-JNK, NADPH oxidase4(NOX4), p22, Bax and Bcl-2 were measured by western blot analysis. The mRNA expression levels of NOX4 and p22 were measured by RT-PCR. It was identified that MFA markedly suppressed the ethanol-induced apoptosis and necrosis of L-02 cells. In addition, MFA decreased the expression levels of superoxide dismutase, catalase and phospholipid hydroperoxide gluthione peroxidase, and downregulated the levels of Bax/Bcl-2 and the cleaved forms of caspase-3 in a dose- and time-dependent manner. This indicated that MFA attenuated the apoptosis of L-02 cells. MFA also decreased the elevated mRNA and protein expression levels of Nox4 and p22phox, and the production of intracellular ROS triggered by ethanol. Further analysis demonstrated that MFA significantly attenuated the phosphorylation of JNK and p38, which are major components of the mitogen-activated protein kinase(MAPK) pathways. On the whole, the findings of this study demonstrated that MFA attenuated the apoptotic cell death of L-02 cells by reducing the generation of ROS and inactivating the MAPK pathways.

20-hydroxyecdysone protects wheat seedlings from salt stress

20-Hydroxyecdysone (20E), a molting hormone of insects, is the most abundant phytoecdysteroid (PE) produced by plants, where it represents a protective molecule against insect herbivores. The objective of the investigation is to determine the effect of 20E on the growth, physiological and biochemical characteristics and the transcript levels of antioxidant enzymes of wheat seedlings under salt stress. Our results showed that exogenous 20E was able to significantly alleviate salt-induced oxidative damage in wheat seedlings. It most likely acts by decreasing the concentration of malondialdehyde (MDA) and the rate of superoxide radical (O 2 •− ) generation, and by increasing the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), concentrations of ascorbic acid (AsA) and glutathione (GSH), and the gene expression levels of SOD , POD , CAT . It was suggested that foliar spraying with 20E could efficiently protect wheat seedlings against salt-induced oxidative stress. The results also show that 20E had a positive physiological effect on the growth of salt-stressed seedlings. This is the first report dealing with the effect of 20E pretreatment in the enhancing of wheat seedling tolerance under salt stress. https://doi.org/10.2298/ABS170722056L Received: July 22, 2017; Revised: November 14, 2017; Accepted: December 11, 2017; Published online: December 22, 2017 How to cite this article: Li J, Han X, Tang L, Wang C, Zhang W, Ma J. 20-hydroxyecdysone protects wheat seedlings from salt stress. Arch Biol Sci. 2018;70(2):379-86.

Acute nutrient treatment causes alterations in intra-follicular antioxidation and AKT signaling.

This study aimed to determine if short-term nutrient alteration affects (1) ovarian morphology, (2) plasma and ovarian antioxidant capability and (3) cell apoptosis and AKT signaling within the ovary. After estrus synchronization, 24 Hu sheep were assigned to three groups based on the nutrient requirement recommended for maintenance (M): 1 × M (Control), 1.5 × M (S) and 0.5 × M (R) during days 7-14 of their estrous cycle. The results indicated that undernourishment significantly increased the counts and volume of follicles <2.5 mm and decreased the counts and volume of follicles ≥2.5 mm (P < 0.05). Feed restriction altered the plasma and follicular redox balance within follicles ≥2.5 mm by inhibiting total antioxidant capacity, increasing malondialdehyde concentration (P < 0.05) and reducing the mRNA expression levels of superoxide dismutase 2 (SOD2) and glutathione peroxidase (GSH-PX), as well as the activities of total SOD and GSH-PX. Feed restriction also attenuated B-cell lymphoma-2 (BCL2) but enhanced Bcl-2-associated X protein (BAX) and BAX/BCL2 transcription and translation levels in granulosa cells (P < 0.05). Uniform staining intensities of AKT and P-AKT-Ser473 were observed in each follicle stage, whereas weaker P-AKT-Thr308 staining in the antral follicle than in the pre-antral follicle suggested possible involvement of P-AKT-Thr308 during the beginning of follicle development. P-AKT-Ser473 levels in follicles ≥2.5 mm was significantly reduced in the R group (P < 0.05). The results presented in this study demonstrate that suppressed folliculogenesis caused by feed restriction might be associated with attenuated AKT signaling, reduced follicular antioxidant capacity and enhanced granulosa cells apoptosis.

Paraquat affects mitochondrial bioenergetics, dopamine system expression, and locomotor activity in zebrafish (Danio rerio)

The dipyridyl herbicide paraquat induces oxidative stress in cells and is implicated in adult neurodegenerative diseases. However, less is known about paraquat toxicity in early stages of vertebrate development. To address this gap, zebrafish (Danio rerio) embryos were exposed to 1, 10 and 100 μM paraquat for 96 h. Paraquat did not induce significant mortality nor deformity in embryos and larvae, but it did accelerate time to hatch. To evaluate whether mitochondrial respiration was related to earlier hatch times, oxygen consumption rate was measured in whole embryos. Maximal respiration of embryos exposed to 100 μM paraquat for 24 h was reduced by more than 70%, suggesting that paraquat negatively impacts mitochondrial bioenergetics in early development. Based upon this evidence for mitochondrial dysfunction, transcriptional responses of oxidative stress- and apoptosis-related genes were measured. Fish exposed to 1 μM paraquat showed higher expression levels of superoxide dismutase 2, heat shock protein 70, Bcl-2-associated X protein, and B-cell CLL/lymphoma 2a compared to control fish. No differences among groups were detected in larvae exposed to 10 and 100 μM paraquat, suggesting a non-monotonic response. We also measured endpoints related to larval behavior and dopaminergic signaling as paraquat is associated with degeneration of dopamine neurons. Locomotor activity was stimulated with 100 μM paraquat and dopamine transporter and dopamine receptor 3 mRNA levels were increased in larvae exposed to 1 μM paraquat, interpreted to be a compensatory response at lower concentrations. This study improves mechanistic understanding into the toxic actions of paraquat on early developmental stages.

Antioxidant gene expression and metabolic responses of earthworms (Eisenia fetida) after exposure to various concentrations of hexabromocyclododecane

Hexabromocyclododecane (HBCD), a ubiquitous suspected contaminant, is one of the world's most prominent brominated flame retardants (BFRs). In the present study, earthworms (Eisenia fetida) were exposed to HBCD. The expression of selected antioxidant enzyme genes was measured, and the metabolic responses were assessed using nuclear magnetic resonance (NMR) to identify the molecular mechanism of the antioxidant stress reaction and the metabolic reactions of earthworms to HBCD. A significant up-regulation (p < 0.05) of superoxide dismutase (SOD) gene expression was detected, with the highest gene expression level of SOD appearing at a dose of 400 mg kg−1 dw (2.06-fold, p < 0.01). However, the glutathione transferase (GST) gene expression levels did not differ significantly (p > 0.05). Principal component analysis (PCA) of the metabolic responses showed that all groups could be clearly differentiated, and the highest concentration dose group was the most distant from the control group. Except for fumarate, the measured metabolites, which included adenosine triphosphate (ATP), valine, lysine, glycine, betaine and lactate, revealed significant (p < 0.05) increases after 14 days of exposure to HBCD. HBCD likely induces high levels of anaerobic respiration, which would result in high levels of ATP and lead to the disintegration of proteins into amino acids, including valine and lysine, to produce energy. The observed changes in osmotic pressure were indicative of damage to the membrane structure. Furthermore, this study showed that NMR-based metabolomics was a more sensitive tool than measuring the gene expression levels for elucidating the mode of toxicity of HBCD in earthworm exposure studies.

Background Nutrients Affect the Biotransformation of Tetracycline by Stenotrophomonas maltophilia as Revealed by Genomics and Proteomics.

Certain bacteria are resistant to antibiotics and can even transform antibiotics in the environment. It is unclear how the molecular mechanisms underlying the resistance and biotransformation processes vary under different environmental conditions. The objective of this study is to investigate the molecular mechanisms of tetracycline resistance and biotransformation by Stenotrophomonas maltophilia strain DT1 under various background nutrient conditions. Strain DT1 was exposed to tetracycline for 7 days with four background nutrient conditions: no background (NB), peptone (P), peptone plus citrate (PC), and peptone plus glucose (PG). The biotransformation rate follows the order of PC > P > PG > NB ≈ 0. Genomic analysis showed that strain DT1 contained tet(X1), a gene encoding an FAD-binding monooxygenase, and eight peroxidase genes that could be relevant to tetracycline biotransformation. Quantitative proteomic analyses revealed that nodulation protein transported tetracycline outside of cells; hypoxanthine-guanine phosphoribosyltransferase facilitated the activation of the ribosomal protection proteins to prevent the binding of tetracycline to the ribosome and superoxide dismutase and peroxiredoxin-modified tetracycline molecules. Comparing different nutrient conditions showed that the biotransformation rates of tetracycline were positively correlated with the expression levels of superoxide dismutase.

In Vivo and In Vitro Analysis in Coronary Artery Disease Related to Type 2 Diabetes.

The leading cause of morbidity and mortality in patients with type 2 diabetes mellitus (DM) is coronary artery disease (CAD), a condition often asymptomatic but severe in these patients. Although glucose metabolism impairment and oxidative stress are known actors in the endothelial dysfunction/remodeling that occurs in diabetic patients, the relationship between cardiovascular disorders and DM is not fully understood. We have performed both an in vivo imaging and in vitro molecular analysis to investigate diabetic-specific CAD alterations. Computed tomography coronary angiography (CTCA) was performed in a group of 20 diabetic patients with CAD (DM+CAD+), 20 non-diabetic with CAD (DM-CAD+), 10 diabetic non-CAD patients (DM+CAD-), and 20 non-diabetic healthy subjects (HS). Imaging quantitative parameters such as calcium score (Cascore), calcified plaque volume (CPV), non-calcified plaque volume (NCPV), total plaque volume (TPV), remodeling index (RI), and plaque burden were extracted for each CAD subject. Moreover, the expression levels of superoxide dismutase 2 (SOD2) and liver X receptor alpha (LXRα) genes were analyzed in the peripheral blood mononuclear cells, whereas hyaluronan (HA) concentrations were evaluated in the plasma of each subject. Imaging parameters, such as Cascore, CPV, RI, and plaque burden, were significantly higher in DM+CAD+ group, compared to DM-CAD+ (P = 0.019; P = 0.014; P < 0.001, P < 0.001, respectively). SOD2 mRNA was downregulated, while LXRα gene expression was upregulated in DM+CAD-, DM+CAD+, and DM-CAD+ groups compared to HS (P = 0.001, P = 0.03, and P = 0.001 for SOD2 and P = 0.006, P = 0.008, and P < 0.001 for LXRα, respectively). Plasmatic levels of HA were higher in DM-CAD+, DM+CAD-, and DM+CAD+ groups, compared to HS (P = 0.001 for the three groups). When compared to DM-CAD+, HA concentration was higher in DM+CAD- (P = 0.008) and DM+CAD+ (P < 0.001) with a significant difference between the two diabetic groups (P = 0.003). Moreover, HA showed a significant association with diabetes (P = 0.01) in the study population, and the correlation between HA levels and glycemia was statistically significant (ρ = 0.73, P < 0.001). In our population, imaging parameters highlight a greater severity of CAD in diabetic patients. Among molecular parameters, HA is modulated by diabetic CAD-related alterations while SOD2 and LXRα are found to be more associated with CAD but do not discriminate between diabetic and non-diabetic subgroups.

Effects of protein sources on growth, immunity and antioxidant capacity of juvenile pearl oyster Pinctada fucata martensii

In this study, we formulated five diets, namely, P1, P2, P3, P4 and P5, with Chlorella sp. powder, Spirulina platensis powder, yeast powder, soybean meal and corn gluten, respectively, as major protein sources. A feeding experiment was designed to evaluate the effects of formulated diets on the growth performance, immunity and antioxidant and biomineralization capacity of juvenile pearl oyster (Pinctada fucata martensii). In the experiments, the five groups were separately fed with P1, P2, P3, P4 and P5 diets. After 45 days of feeding, pearl oysters fed on P1, P2, P3 and P4 diets showed significantly higher absolute growth rate and protease and amylase activities than those fed on P5 diet (P < 0.05). Moreover, pearl oysters fed on P1, P2, P3 and P4 diets exhibited significantly higher activities of alkaline phosphatase (AKP), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) (P < 0.05). Significantly higher expression levels of SOD, GPx, CAT, heat shock protein (HSP) 70, HSP90, nacrein, pif177 and pearlin mRNA were observed in pearl oysters fed on P1, P2, P3 and P4 diets relative to those fed on P5 (P < 0.05). Results suggested the suitability of Chlorella sp. powder, S. platensis powder, yeast powder and soybean meal as protein sources for development of formulated diets for pearl oyster P. f. martensii.

Does Metformin Protect Diabetic Patients from Oxidative Stress and Leukocyte-Endothelium Interactions?

Since metformin can exert beneficial vascular effects, we aimed at studying its effect on reactive oxygen species (ROS) production, antioxidant enzyme expression, levels of adhesion molecules, and leukocyte-endothelium interactions in the leukocytes from type 2 diabetic (T2D) patients. The study was carried out in 72 T2D patients (41 of whom were treated with metformin for at least 12 months at a dose of 1700 mg per day), and in 40 sex- and age-matched control subjects. Leukocytes from T2D patients exhibited enhanced levels of mitochondrial ROS and decreased mRNA levels of glutathione peroxidase 1 (gpx1) and sirtuin 3 (sirt3) with respect to controls, whereas metformin was shown to revert these effects. No changes were observed on total ROS production and the expression levels of superoxide dismutase 1 and catalase. Furthermore, increases in leukocyte-endothelial interactions and intercellular adhesion molecule-1 and P-selectin levels were found in T2D and were also restored in metformin-treated patients. Our findings raise the question of whether metformin could modulate the appearance of atherosclerosis in T2D patients and reduce vascular events by decreasing leukocyte oxidative stress through an increase in gpx1 and sirt3 expression, and undermining adhesion molecule levels and leukocyte-endothelium interactions. Antioxid. Redox Signal. 27, 1439-1445.

Effects of dietary chitosan on growth, lipid metabolism, immune response and antioxidant-related gene expression in Misgurnus anguillicaudatus.

This study was performed to evaluate the effects of dietary chitosan supplementation on growth performance, lipid metabolism, gut microbial, antioxidant status and immune responses of juvenile loach (Misgurnus anguillicaudatus). Five experimental diets were formulated to contain graded levels of chitosan (0 (control), 0.5, 1, 2 and 5% CHI) for 50 days. Results of the present study showed that body weight gain was significantly higher in fish fed chitosan supplemented diets in dose dependent manner than control group. Increasing dietary chitosan levels reduced gut lipid content. Meanwhile the mRNA expression levels of intestine lipoprotein lipase and fatty acid binding protein 2 were significantly reduced with incremental dietary chitosan level. The percentages of total monounsaturated fatty acid decreased, while polyunsaturated fatty acid increased with dietary chitosan. The fish fed 0.5% CHI had higher mucus lysozyme activity (LZM) than those fed 0% CHI, but the LZM activity was significantly decreased with advancing chitosan supplement. The expression levels of superoxide dismutase, catalase and glutathione peroxidase revealed a similar trend, where the highest expressions were found in fish fed 5% CHI diet. In the term of intestine microbiota between 0 and 1% CHI groups, the proportion of bacteria in the phylum Bacteroidetes increased, whereas the proportion of bacteria in the phylum Firmicutes decreased as the fish supplemented chitosan. In conclusion, supplementation of chitosan improved growth performance, antioxidant status and immunological responses in loach.

Alteration of oxidative stress and inflammatory cytokines induces apoptosis in diabetic nephropathy.

Diabetic nephropathy (DN) is one of the most significant long‑term complications in terms of morbidity and mortality for diabetic patients; however, the exact cause remains unknown. To address this, the DN model was established, and oxidative stress indexes, including malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH‑Px), and inflammatory cytokines, includinginterleukin‑6 (IL‑6), tumor necrosis factor‑alpha (TNF‑α) and transforming growth factor‑beta (TGF‑β), were examined by ELISA. Renal pathological alterations and cell apoptosis was examined by hematoxylin and eosin and terminal deoxynucleotidyl transferase mediated dUTP nick‑end labeling staining, respectively. The expression levels of B‑cell lymphoma‑2 (Bcl‑2), Bcl‑2 associated X (Bax) and caspase‑3 wereexamined by immunohistochemistry and western blotting. The DN model was correctly established, with lower body weight and the higher blood glucose in the diabetes model group. The expression levels of SOD and GSH‑Px were significantly decreased in the diabetes model group; however, MDA, IL‑6, TNF‑α and TGF‑β were significantly increased. The kidney was severely damaged in the diabetes model group, with inflammatory cell invasion, increasing amount of interstitial matrix and hypertrophy with vacuolar degeneration of renal tubular cells. Cell apoptosis levels were significantly increased, and Bcl‑2 was significantly decreased in the diabetes model group in contrast with that of the sham group; however, Bax and caspase‑3 were significantly increased. It suggested that increased oxidative stress and inflammatory cytokines may enhance the apoptosis levels in DN, and may provide a significant diagnostic reference for DN in diabetes patients.

Histopathological findings of renal tissue induced by oxidative stress due to different concentrations of fluoride.

It has been reported that excessive intake of fluoride can induce renal lesions. However, its pathogenesis is still less understood. Therefore, this study was conducted to investigate oxidative damage and the relationships between the oxidative damage and renal lesions in fluoride-treated mice by using the methods of histopathology, biochemistry, flow cytometry and quantitative real-time polymerase chain reaction (qRT-PCR). A total of 240 ICR mice were randomly divided into four equal groups (sodium fluoride was given orally at the dose of 0, 12, 24 and 48 mg/kg body weight for 42 days, respectively). We found that fluoride in excess of 12 mg/kg induced renal oxidative damage, which was characterized by increasing the levels of reactive oxygen species (ROS) production and contents of malondialdehyde (MDA) and protein carbonyls (PC), and decreasing the abilities of anti-superoxide anion (ASA) and anti-hydroxyl radical (AHR), glutathione (GSH) content, as well as activities and mRNA expression levels of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and glutathione peroxidase (GSH-Px). Concurrently, fluoride caused degeneration and necrosis of the tubular cells, renal tubular hyaline casts and glomeruli swelling, which were consistent with the alteration of renal function parameters including elevated contents of serum creatinine (Cr), serum uric acid (UA), blood urea nitrogen (BUN), and the activities of urinary N-acetyl-b-D-glucosaminidase (NAG), renal lactate dehydrogenase (LDH), and reduced activities of sodium-potassium adenosine triphosphatase (Na+/K+-ATPase) and acid phosphatase (ACP) in the kidney. The above-mentioned results showed that fluoride in excess of 12 mg/kg induced renal oxidative damage, which then caused renal lesions and dysfunctions. These findings also clearly demonstrated that oxidative damage is one of the mechanisms of fluoride-induced renal lesions and dysfunctions.

Hydrogen sulfide reduced renal tissue fibrosis by regulating autophagy in diabetic rats.

The present study aimed to explore the effect of hydrogen sulfide (H2S) on renal tissue fibrosis and its mechanism in diabetic rats. Rats were randomly divided into four groups (n=13/group): Control group; induced diabetes mellitus group (STZ); induced diabetes mellitus treated with H2S group (STZ + H2S); normal rats treated with H2S group (H2S). The diabetic model was induced by intraperitoneal (i.p.) injections of 40 mg/kg body weight streptozotocin (STZ); the control group was treated with saline every day (i.p); NaHS (100 µmol/kg i.p.) was administered to rats of STZ + H2S group and H2S group. After 8 weeks, rat body weight and 24 h proteinuria levels were determined in each group, renal pathological morphology was analyzed by Masson's trichrome staining, collagen IV content was detected by immunohistochemistry, and periodic acid-Schiff (PAS) staining was performed on renal glomerular and tubular basement membranes. The expression levels of matrix metalloproteinase 9 (MMP9), MMP7, tissue inhibitor of metalloproteinase 1 (TIMP1), superoxide dismutase (SOD), serine/threonine kinase AKT, transforming growth factor (TGF)-β1, nuclear factor (NF)-κB and several autophagy related proteins were assessed by western blot analysis. Compared with the control group, renal tissue fibrosis was observed, collagen IV expression and the 24 h proteinuria quantity was markedly increased and the amount of PAS positive material in renal glomerular and tubular basement membranes was notably increased in STZ-treated rats. Furthermore, the expression levels of MMP9, MMP7, TIMP1, autophagy-associated proteins, AKT, TGF-β1 and NF-κB protein were significantly increased, and SOD expression levels were significantly decreased in the STZ group compared with the control (P<0.05). In the H2S+STZ group, renal tissue fibrosis and the expression of collagen IV were improved, 24 h proteinuria was decreased, the amount of PAS positive material in renal glomerular and tubular basement membranes was decreased, the expression levels MMP9, MMP7, TIMP1, autophagy-associated proteins, AKT, TGF-β1 and NF-κB protein were significantly decreased, and the expression levels of SOD were significantly increased compared with the STZ group (P<0.05). In conclusion, H2S may improve renal tissue fibrosis by inhibiting autophagy, upregulating SOD and downregulating AKT, TGF-β1 and NF-κB.

Schisandrin B attenuates the inflammatory response, oxidative stress and apoptosis induced by traumatic spinal cord injury via inhibition of p53 signaling in adult rats.

Schisandrin B is an active monomer of the Chinese magnolia vine (Schisandra chinensis) that can reduce transaminase activity in liver cells, inhibit lipid peroxidation, enhance antioxidant status, has protective effects in the liver and has antitumor effects. The present study investigated the potential protective effects of schisandrin B on the p53 signaling pathway in attenuating the inflammatory response, oxidative stress and apoptosis induced by traumatic spinal cord injury (TSCI) in adult rats. Behavioral examination, inclined plate test and spinal cord water content were used to evaluate the protective effect of schisandrin B in TSCI rats. The expression levels of superoxide dismutase (SOD), malondialdehyde (MDA), nuclear factor (NF)-κB subunit p65 and tumor necrosis factor (TNF)-α were examined using ELISA kits. Western blot analysis was performed to analyze the protein expression of caspase-3 and phosphorylated (p)-p53 in TSCI rats. In the present study, schisandrin B improved behavioral examination results and the maximum angle of inclined plate test, and inhibited spinal cord water content in rats with TSCI. Notably, schisandrin B reduced the activation of traumatic injury-associated pathways, including SOD, MDA, NF-κB p65 and TNF-α, in TSCI rats. In addition, schisandrin B suppressed the TSCI-induced expression of caspase-3 and p-p53 in TSCI rats. These results indicated that schisandrin B may attenuate the inflammatory response, oxidative stress and apoptosis in TSCI rats by inhibiting the p53 signaling pathway in adult rats.