Matrine inhibits advanced glycation end products-induced macrophage M1 polarization by reducing DNMT3a/b-mediated DNA methylation of GPX1 promoter

Advanced glycation end products (AGEs) are characterized diabetic metabolites inducing macrophage M1 polarization which is crucial in diabetes-exacerbated atherosclerosis. Matrine was proved anti-atherosclerotic. The current study was aimed to investigate the inhibitory effects of matrine on AGEs- induced macrophage M1 polarization and underlying molecular mechanisms. Primary mouse macrophages were exposed to AGEs. Receptor for AGEs (RAGE) and toll-like receptor 4 (TLR4) were over-expressed by vectors. Matrine was used to treat these cells. Inducible nitric oxide synthase (iNOS) expression and pro-inflammatory cytokine production were used to evaluate macrophage M1 polarization. Oxidative stress was assessed by intracellular reactive oxygen species (ROS) generation, total antioxidant capacity (TAC) and malondialdehyde (MDA) contents. Relative mRNA expression level was determined by real-time PCR. Western blotting was used to evaluate protein and protein phosphorylation levels. Bisulfite sequencing PCR (BSP) was used to evaluate DNA methylation. Matrine reduced AGEs exposure-elevated expressions of DNA methyltransferase (DNA MTase, DNMT)3a and DNMT3b in macrophages which were not affected by RAGE or TLR4 over expressions. DNA methylation rate of GPX1 promoter was reduced from 97.22% to 66.67% in AGEs- exposed macrophages treated by matrine. GPX1 expression was up-regulated by matrine, which further suppressed AGEs/RAGE-mediated oxidative stress. Thus, the activation of down-stream TLR4/STAT1 signaling pathway was inhibited by matrine treatment which eventually suppressed AGEs- induced macrophage M1 polarization. However, these effects of matrine were impaired by RAGE and TLR4 overexpression. Results from this study suggested that matrine inhibited AGEs- induced macrophage M1 polarization by suppressing RAGE-induced oxidative stress-mediated TLR4/STAT1 signaling pathway. Matrine exerted anti-oxidant effects via increasing GPX1 expression by inhibiting DNMT3a/b-induced GPX1 promoter DNA methylation.

Gene expression and alterations of antioxidant enzymes in spleen of rats exposed to fluoride

BACKGROUND

Fluorosis is a slow and progressive process causing metabolic, functional and structural damages affecting many tissues particularly musculoskeletal, dental systems, kidney, liver and brain. It can be rapidly absorbed by passive diffusion through the stomach, small intestine, mouth and skin. Endemic fluorosis is connected to the high concentration of fluoride in drinking water. The present study aimed to evaluate the toxic effects of sodium fluoride (NaF) on splenic activity at the biochemical and molecular level.

MATERIALS AND METHODS

Wistar albino rats were randomly assigned to three groups. The control rats were given 1 ml deionized water orally for 40 days. Groups II and III were administered 300 and 600 mg NaF/kg b.w. /day for the same period. Animals were sacrificed under ether anaesthesia. The spleen tissue was excised and used for biochemical and real-time PCR analysis. The level of fluoride, malondialdehyde (MDA), reduced glutathione (GSH) and activities of different antioxidant enzymes such as cytosolic copper/zinc superoxide dismutase (Cu/Zn SOD), glutathione peroxidase (GPx) and catalase (CAT) were determined. The analysis of gene expression of Cu/Zn SOD, GPx and CAT in spleen was done using Real-time PCR.

RESULTS

The levels of fluoride and MDA were significantly (P < 0.0001) increased where as GSH content decreased significantly (P < 0.0001) in the spleen of fluoridated rats. The activities of antioxidant enzymes viz; Cu/Zn SOD, GPx and CAT declined significantly (P < 0.0001) compared to the control. Pearson's bivariate correlation and simple linear regression analysis exhibited strong positive correlation between levels of splenic tissue fluoride and MDA(r = 0.985) while negative correlations existed in GSH (r = -0.907) as well as activities of Cu/Zn SOD (r = -0.982), GPx (r = -0.966), and CAT (r = -0.935). The gene expression of Cu/Zn SOD, GPx and CAT were significantly (P < 0.0001) reduced in fluorotic rats.

CONCLUSION

It is concluded that fluoride intoxication leads to the development of oxidative stress and damaging the cellular metabolism resulting in the declined ability of free radical scavengers along with increased level of MDA and decreased expression level of antioxidant genes which helps to understand the possible mechanism of fluoride-induced toxicity at the molecular level.

Enrichment of polystyrene microplastics induces histological damage, oxidative stress, Keap1-Nrf2 signaling pathway-related gene expression in loach juveniles (Paramisgurnus dabryanus)

Polystyrene microplastics (PS-MPs, particle size<5 mm) cause great harm to aquatic organisms. However, their precise effects are not completely understood. In China, placing plastic film at the pond bottom has become an important loach aquaculture mode. In this mode, MPs will affect loach health. This study investigated the enrichment of PS-MPs and its effects on the growth, liver histomorphology, antioxidant enzymes, and Keap1-Nrf2 signaling pathway-related gene expression in loach juveniles (Paramisgurnus dabryanus). The loach juveniles were raised at the concentration of 1000 μg/L fluorescent polystyrene microplastics (PS-MPs) with particle size of 0.5 µm or 5 µm for seven days, the results showed that fluorescent PS-MPs were found to be enriched in liver, intestine, and gill, and the enrichment amount was higher in liver than in gill and intestine (P < 0.05). Furthermore, the enrichment amount of different-sized PS-MPs was different in liver, gill, and intestine. The loach juveniles were cultured for 21 days in the water of the concentration of 100 or 1000 μg/L PS-MPs with particle size of 0.5 µm or 5 µm, the results showed that the survival rate, weight gain rate, and specific growth rate of loach juveniles were significantly reduced. The histological analysis revealed that PS-MPs caused liver damage. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-PX), and acetylcholinesterase (AChE) were decreased with the extended exposure to PS-MPs. Generally, the expressions of Nrf2 and Keap1 showed the similar change trend. From 7-14 day, the expression trend of oxidative stressed-related genes was not completely consistent with that of Nrf2 gene, but on day 21, the gene expression trend of oxidative stress-related SOD, CAT, and GSH-PX in the downstream of Keap1-Nrf2 signaling pathway was roughly consistent with that of Nrf2 gene. Basically, the change trends of these three gene expression were similar to those of their corresponding enzyme activities. This study provides theoretical basis for the toxicological effects of PS-MPs on freshwater fish.

Sodium selenite and Se-enriched yeast supplementation in atherosclerotic patients: Effects on the expression of pyroptosis-related genes and oxidative stress status

BACKGROUND AND AIMS

Atherosclerosis as a chronic inflammatory disorder of the arterial wall is the main leading cause of the cardiovascular disease (CVD). Caspase-dependent pyroptosis plays a pivotal role in the pathogenesis of CVD. Selenium (Se) is an important component of the antioxidant defense and plays a crucial role in cardiovascular health. This study aimed to investigate the effects of daily consumption of sodium selenite and Se-enriched yeast on the expression of pyroptosis-related genes, and biomarkers of oxidative stress in patients with atherosclerosis.

METHODS AND RESULTS

In this randomized, double-blinded, placebo-controlled clinical trial, 60 patients with atherosclerosis were recruited. Participants received 200 μg/day of sodium selenite, Se-enriched yeast, or placebo for 8 following weeks. The pyroptosis-related genes' mRNA expression in peripheral blood mononuclear cells (PBMCs) was assessed before and after the intervention. Also, the levels of superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO), and glutathione peroxidases (GPX) were measured at baseline and following the intervention. Following sodium selenite and Se-enriched yeast supplementation, the relative expression levels of TLR4, ASC, NLRP3, and NF-κB1 were significantly downregulated (p < 0.05). Furthermore, the changes in GPX were significantly increased after selenite and yeast supplementation (p < 0.05). Also, selenite and yeast consumption caused a statistically significant decrease in the change of MDA level (p < 0.05).

CONCLUSION

In summary, these findings showed that Se supplementation may reduce inflammation through down-regulation of some pro-inflammatory genes, improving antioxidant defenses in atherosclerosis patients. Further research is required to come to a definite conclusion of selenium supplementation on the CVD risk. This study was registered on the Iranian Registry of Clinical Trials website (identifier: RCT20110123005670N28; https://www.irct.ir/).

Glutathione peroxidase family and survival prognosis in patients with renal cell carcinoma

OBJECTIVES

Renal cell carcinoma (RCC) is a renal cortical tumor with high clinical incidence. The effect of glutathione peroxidases (GPXs) on RCC and the possible mechanism are still unclear. This study aims to explore the expression level of GPXs gene in RCC and its effect on the clinical prognosis of patients with RCC via bioinformatics analysis.

METHODS

The mRNA expressions of GPXs family genes were obtained from the public data of The Cancer Genome Atlas (TCGA) database. The Kruskal-Wails test was used to analyze the differences in mRNA expression of GPXs family genes between samples from patients with RCC and the normal population. UALAN databases were used to analyze the differences in protein expression of GPXs family genes between samples from patients with renal clear cell carcinoma and the normal population, and to evaluate the role of GPXs family genes in RCC. The Kaplan-Meier Plotter was used to analyze the correlation between different types of RCC and overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS), and progression-free survival (PFS). Kaplan-Meier survival curve was drawn based on the GPX8 gene expression to study the relationship between GPX8 gene expression and prognosis of RCC patients. Based on the results of multivariate Cox regression analysis, a Nomogram scoring model for RCC prediction was established by introducing GPX8 gene.

RESULTS

The mRNA expressions of GPX1 and GPX4 were higher in the sample of renal chromophobe cell carcinoma, renal clear cell carcinoma, and renal papillary cell carcinoma than those in the normal population (all P<0.01), and GPX7 and GPX8 were significantly over-expressed in patients with renal papillary cell carcinoma and renal clear cell carcinoma (all P<0.01). Compared with the normal group, the protein expressions of GPX1, GPX2, GPX7, and GPX8 were increased significantly in renal clear cell carcinoma (all P<0.01), while GPX3 and GPX4 expressions were decreased significantly (both P<0.01). The protein expressions of GPX1, GPX2, GPX7, and GPX8 were increased significantly in patients with renal clear cell carcinoma at different tumor grades (all P<0.01), while GPX3 and GPX4 expressions were decreased significantly (both P<0.01). Survival analysis showed that OS, DFS, DSS, and PFS were all decreased in patients with clear cell carcinoma compared with patients with papillary cell carcinoma and chromophobe cell carcinoma. According to the GPX8 level, patients were assigned into the low, medium, and high expression groups. Compared with the low GPX8 level group, the OS (P<0.01), DFS (P=0.03), DSS (P<0.01), and PFS (P=3.18×10-7) were significantly decreased in the high level group. Univariate Cox proportional regression analysis showed that the high level of GPX8 was associated with poor OS of 3 different types of renal cancer. Multifactorial analysis showed that GPX8 was an independent factor affecting the OS of patients with renal papillary cell carcinoma. Race and post tumor node metastasis (pTNM) typing were independent factors influencing the OS of patients with renal clear cell carcinoma. GPX8 and pTMN were independent factors influencing the OS of patients with renal chromophobe cell carcinoma. Based on these variables, the Nomogram risk models of 3 types of cell carcinoma were established, and the discrimination and calibration of the models were evaluated using the Consistency index (C-index) and calibration curves. The C-index of the risk model of renal papillary cell carcinoma was 0.62 (95% CI 0.51 to 1.00, P=0.03). The results of receiver operating characteristic (ROC) curve showed that the area under the curve (AUC) was 0.88. The C-index of the risk model of renal clear cell carcinoma was 0.72 (95% CI 0.52 to 1.00, P=0.03). The results of ROC curve showed that the AUC was 0.90. The C-index of the risk model of chromophobe cell carcinoma of kidney was 0.90 (95% CI 0.85 to 1.00, P<0.01). The results of ROC curve showed that the AUC was 0.59.

CONCLUSIONS

GPXs family genes, especially GPX8, are potential markers for poor prognosis of RCC, and the occurrence and development of RCC can be predicted in clinical practice based on the expressions of GPXs family genes.

Crosstalk between the Arabidopsis Glutathione Peroxidase-Like 5 Isoenzyme (AtGPXL5) and Ethylene

Glutathione peroxidases (GPXs) are important antioxidant enzymes in animals. Plants contain GPX-like (GPXL) enzymes, which-in contrast to GPXs-contain cysteine in their active site instead of selenocysteine. Although several studies proved their importance in development and stress responses, their interaction with ethylene (ET) signalling is not known. Our aim was to investigate the involvement of AtGPXL5 in ET biosynthesis and/or signalling using Atgpxl5 mutant and AtGPXL5 cDNA-overexpressing (OX-AtGPXL5) lines. Four-day-old dark-grown Atgpxl5 seedlings had shorter hypocotyls and primary roots, while OX-AtGPXL5 seedlings exhibited a similar phenotype as wild type under normal conditions. Six-week-old OX-AtGPXL5 plants contained less H₂O₂ and malondialdehyde, but higher polyamine and similar ascorbate- and glutathione contents and redox potential (E_GSH) than the Col-0. One-day treatment with the ET-precursor 1-aminocyclopropane-1-carboxylic acid (ACC) induced the activity of glutathione- and thioredoxin peroxidases and some other ROS-processing enzymes. In the Atgpxl5 mutants, the E_GSH became more oxidised; parallelly, it produced more ethylene after the ACC treatment than other genotypes. Although the enhanced ET evolution measured in the Atgpxl5 mutant can be the result of the increased ROS level, the altered expression pattern of ET-related genes both in the Atgpxl5 and OX-AtGPXL5 plants suggests the interplay between AtGPXL5 and ethylene signalling.

Predisposition of SOD1, GPX1, CAT genetic variants and their haplotypes in cataractogenesis of type 2 diabetes mellitus in Pakistan

AIMS

Cataract formation is accelerated by hyperglycemia due to the excessive production of oxidative stress. This study aimed to examine the underlaying role of glutathione peroxidase 1 (GPX1) rs1800668, catalase (CAT) rs1001179 and superoxide dismutase 1 (SOD1) 50 bp Indel promotor region variants in the pathogenesis of cataract in patients with diabetes.

METHODS

A population-based case-control study of n=680 individuals was conducted which comprised of four respective groups: type 2 diabetes mellitus, diabetic cataract, senile cataract patients and controls. Screening of genotypes was performed by allele-specific (AS) and conventional polymerase chain reaction (PCR). Statistical testing was carried out using SPSS© 20.0, MedCal© and SNPStats© software's. Bioinformatics analysis of linkage disequilibrium was done by HaploView© software 7.0.

RESULTS

GPX1 (rs1800668) showed significant association with higher susceptibility of opacification in type 2 diabetes mellitus (χ²=23.0, Adjusted OR=1.63, 95% CI: 1.05-2.49, p<0.001). A protective role was anticipated by CAT variant (rs1001179) for the development of resistance against the pathogenicity of cataract with diabetes (χ² = 107, Adjusted OR=0.17, 95% CI: 0.10-0.29, p<0.001). Linkage disequilibrium (LD) plot of GPX1 and CAT variants revealed that CTC-CTT haplotypes demonstrated the presence of linkage (D'=1.0) and co-inheritance (LOD=13.84) in patients of diabetic cataract.

CONCLUSIONS

GPX1 (rs1800668) variant may serve as an antioxidant biomarker for the assessment of risk for cataract in type 2 diabetes mellitus. GPX1 enzyme owed an antioxidant activity which can reduce the oxidative stress and hence could develop resistance in cataractogenesis. The findings could be beneficial as a potential target to the future pharmacogenomic studies of cataract prevention and eradication in diabetes mellitus.

CpG methylation of the GPX3 promoter in patients with Kashin-Beck Disease potentially promotes chondrocyte apoptosis

OBJECTIVE

To determine the methylation levels of CpGs in the GPX3 promoter region and explore their potential effects on the apoptosis of chondrocytes.

METHODS

Blood specimens were collected from 32 participants; 16 KBD patients and 16 healthy subjects. Twenty-five CpGs in the promoter region of GPX3 were identified and detected by MALDI-TOF-MS. Methylation levels of CpGs were compared between KBD patients and healthy subjects as well as among the KBD patients with different degrees. C28/I2 human chondrocytes were treated with tBHP and Na2SeO3. Apoptosis in chondrocytes was examined under a fluorescence microscope.

RESULTS

The methylation levels of GPX3-1_CpG_11 and GPX3-1_CpG_16 in KBD patients were significantly higher than those of healthy subjects (P < 0.05). The methylation levels of the other CpGs were not significantly different between the two groups (P > 0.05). The methylation level of GPX3-1_CpG_24 in KBD patients was significantly higher than those of healthy subjects (P < 0.05). MSP-PCR analysis indicated that the methylation rate of KBD group (9.41%) was significantly higher than that of healthy subjects (1.18%), and that GPX3 DNA methylation increased the risk of acquiring KBD 8 fold (OR = 8.000, 95% CI: 1.023-62.580); The mRNA expression of GPX3 in whole blood of KBD patients was lower than that of healthy subjects (P＜0.05); Compared with the control group, GPX3, GPX1 and GPX4 mRNA level of the tertbutyl hydroperoxide injury group decreased significantly (P < 0.05), after supplementation with Na2SeO3. The rate of chondrocytes apoptosis was decreased with the increasing of GPX3 and GPX4 mRNA levels (P＜0.05) and GPX3 mRNA showed a similar trend without statistically significant (P＞0.05).

CONCLUSION

The methylation patterns of CpGs in GPX3 varied in KBD patients. The experiments indicated that the increased methylation of CpGs within the GPX3 promoter may down-regulate the expression of GPX3, thereby reducing the antioxidant function of GPX3 and promoting chondrocyte apoptosis, both of which accelerates the occurrence of KBD. We therefore propose a new understanding of GPX3's potential epigenetic and genetic mechanisms that contribute to KBD.

Selenium Supplementation Improved Cardiac Functions by Suppressing DNMT2-Mediated GPX1 Promoter DNA Methylation in AGE-Induced Heart Failure

Objective

Advanced glycation end products (AGEs) are featured metabolites associated with diabetic cardiomyopathy which is characterized by heart failure caused by myocyte apoptosis. Selenium was proved cardioprotective. This study was aimed at investigating the therapeutic effects and underlying mechanisms of selenium supplementation on AGE-induced heart failure.

Methods

Rats and primary myocytes were exposed to AGEs. Selenium supplementation was administrated. Cardiac functions and myocyte apoptosis were evaluated. Oxidative stress was assessed by total antioxidant capacity (TAC), reactive oxygen species (ROS) generation, and GPX activity. Expression levels of DNA methyltransferases (DNMTs) and glutathione peroxidase 1 (GPX1) were evaluated. DNA methylation of the GPX1 promoter was analyzed.

Results

AGE exposure elevated intracellular ROS generation, induced myocyte apoptosis, and impaired cardiac functions. AGE exposure increased DNMT1 and DNMT2 expression, leading to the reduction of GPX1 expression and activity in the heart. Selenium supplementation decreased DNMT2 expression, recovered GPX1 expression and activity, and alleviated intracellular ROS generation and myocyte apoptosis, resulting in cardiac function recovery. DNA methylation analysis in primary myocytes indicated that selenium supplementation or DNMT inhibitor AZA treatment reduced DNA methylation of the GPX1 gene promoter. Selenium supplementation and AZA administration showed synergic inhibitory effect on GPX1 gene promoter methylation.

Conclusions

Selenium supplementation showed cardioprotective effects on AGE-induced heart failure by suppressing ROS-mediated myocyte apoptosis. Selenium supplementation suppressed ROS generation by increasing GPX1 expression via inhibiting DNMT2-induced GPX1 gene promoter DNA methylation in myocytes exposed to AGEs.

Role of selenoprotein P expression in the function of pancreatic β cells: Prevention of ferroptosis-like cell death and stress-induced nascent granule degradation

Selenoprotein P (SELENOP) is a major selenium (Se)-containing protein (selenoprotein) in human plasma that is mainly synthesized in the liver. SELENOP transports Se to the cells, while SELENOP synthesized in peripheral tissues is incorporated in a paracrine/autocrine manner to maintain the levels of cellular selenoproteins, called the SELENOP cycle. Pancreatic β cells, responsible for the synthesis and secretion of insulin, are known to express SELENOP. Here, using MIN6 cells as a mouse model for pancreatic β cells and Selenop small interfering (si)RNA, we found that Selenop gene knockdown (KD) resulted in decreased cell viability, cellular pro/insulin levels, insulin secretion, and levels of several cellular selenoproteins, including glutathione peroxidase 4 (Gpx4) and selenoprotein K (Selenok). These dysfunctions induced by Selenop siRNA were recovered by the addition of Se. Ferroptosis-like cell death, regulated by Gpx4, was involved in the decrease of cell viability by Selenop KD, while stress-induced nascent granule degradation (SINGD), regulated by Selenok, was responsible for the decrease in proinsulin. SINGD was also observed in the pancreatic β cells of Selenop knockout mice. These findings indicate a significant role of SELENOP expression for the function of pancreatic β cells by maintaining the levels of cellular selenoproteins such as GPX4 and SELENOK.

GPX4 deficiency-dependent phospholipid peroxidation drives motor deficits of ALS

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by oxidative stress that triggers motor neurons loss in the brain and spinal cord. However, the mechanisms underlying the exact role of oxidative stress in ALS-associated neural degeneration are not definitively established. Oxidative stress-generated phospholipid peroxides are known to have extensive physiological and pathological consequences to tissues. Here, we discovered that the deficiency of glutathione peroxidase 4 (GPX4), an essential antioxidant peroxidase, led to the accumulation of phospholipid peroxides and resulted in a loss of motor neurons in spinal cords of ALS mice. Mutant human SOD1^G93A transgenic mice were intrathecally injected with neuron-targeted adeno-associated virus (AAV) expressing GPX4 (GPX4-AAV) or phospholipid peroxidation inhibitor, ferrostatin-1. The results showed that impaired motor performance and neural loss induced by SOD1^G93A toxicity in the lumbar spine were substantially alleviated by ferrostatin-1 treatment and AAV-mediated GPX4 delivery. In addition, the denervation of neuron-muscle junction and spinal atrophy in ALS mice were rescued by neural GPX4 overexpression, suggesting that GPX4 is essential for the motor neural maintenance and function. In comparison, conditional knockdown of Gpx4 in the spinal cords of Gpx4^fl/fl mice triggered an obvious increase of phospholipid peroxides and the occurrence of ALS-like motor phenotype. Altogether, our findings underscore the importance of GPX4 in maintaining phospholipid redox homeostasis in the spinal cord and presents GPX4 as an attractive therapeutic target for ALS treatment.

MiR-185-5p suppresses acute myeloid leukemia by inhibiting GPX1

Acute myeloid leukemia (AML) has been characterized by the swift development of abnormal cells in the bone marrow. This research aimed to examine the impacts of the miR-185-5p-GPX1 axis on AML progression and differentiation. Findings indicated that miR-185-5p and GPX1 levels were significantly reduced and elevated, respectively. The upregulation of miR-185-5p was observed to restrict the proliferation and invasion abilities of AML cells, and promote differentiate and apoptosis. Moreover, the overexpression of GPX1 was noticed to enhance the growth of AML cells. In conclusion, this research suggested that by targeting GPX1, miR-185-5p inhibited AML progression and downregulated AML cells' proliferation and invasion.

Lysine decrotonylation of glutathione peroxidase at lysine 220 site increases glutathione peroxidase activity to resist cold stress in chrysanthemum

Lysine crotonylation is a protein post-translational modification that has been newly discovered in recent years. There are few studies on the lysine crotonylation of proteins in plants, and their functions in response to cold stress are still unclear. In this study, the chrysanthemum (Chrysanthemum morifolium Ramat.) glutathione peroxidase (GPX) gene was selected and named DgGPX1, and was found to be responsive to low temperature. Overexpression of DgGPX1 improved the cold resistance of transgenic chrysanthemum by increasing GPX activity to reduce the accumulation of reactive oxygen species (ROS) under low-temperature conditions. Furthermore, the level of DgGPX1 lysine crotonylation at lysine (K) 220 decreased under low temperature in chrysanthemum. Lysine decrotonylation of DgGPX1 at K220 further increased GPX activity to reduce ROS accumulation under cold stress, and thereby enhanced the cold resistance of chrysanthemum. The above results show that lysine decrotonylation of DgGPX1 at K220 increases GPX activity to resist cold stress in chrysanthemum.

Capsella bursa-pastoris (L.) Medic. extract alleviate cataract development by regulating the mitochondrial apoptotic pathway of the lens epithelial cells

ETHNOPHARMACOLOGICAL RELEVANCE

Capsella bursa-pastoris (L.) Medic. (CBP) is a cruciferous plant valuable in reducing fever, improving eyesight and calming the liver. This herb was recorded in the Compendium of Materia Medica for cataract treatment.

AIM OF THE STUDY

To determine the effects and mechanism of CBP on cataract prevention and treatment using a selenite cataract model.

MATERIALS AND METHODS

The main compounds in CBP extract were analyzed by UPLC, ¹H-NMR and ¹³C-NMR spectroscopic techniques. Flavonoids formed a significant proportion of its compounds, thus necessitating an evaluation of their inhibitory effects on the development of cataract using a selenite cataract model. The protective effects of CBP flavonoids (CBPF) against oxidative damage and the modulation of mitochondrial apoptotic pathway were subsequently verified on H₂O₂-treated SRA01/04 lens epithelial cells.

RESULTS

CBPF significantly alleviated the development of cataract by decreasing the MDA level and increasing the GSH-Px and SOD levels in the lens. It also inhibited H₂O₂-induced apoptosis in SRA01/04 cells, increased the expression of Bcl-2 protein and decreased the expressions of Caspase-3 and Bax proteins.

CONCLUSION

CBPF exerts a significant preventive effect on cataract development by regulating the mitochondrial apoptotic pathway of the lens epithelial cells. It is thus a potent traditional Chinese medicine (TCM) whose application should be further developed for the clinical treatment of cataract.

Status of prooxidant and antioxidant systems in the sperm and seminal plasma of breeding boars of large white breed and SS23 synthetic line

The indicators of pro- and antioxidant systems in sperm and sperm plasma of breeding boars of Large White breed and SS23 synthetic line were studied. Measurements of antioxidant enzyme activity, determination of lipid peroxidation (LPO) product content, and antioxidant factor were performed. Lipid peroxidation in the semen of healthy breeding boars was characterized by a stable level of activity, which is necessary to ensure normal reproductive functions. Additionally, there was a high content of low molecular weight thiols and proteins. The concentration of SH-groups in spermatozoa was higher (P≤0.05) compared to sperm plasma. The number of total, protein, and free SH-groups in the semen of boars of the synthetic line was higher (P<0.05) in relation to animals of the Large White breed. Low catalase (CAT) activity in the sperm was compensated by glutathione peroxidase (GPX). The content of ceruloplasmin (CP) in the sperm of boars was almost twice as high as that of sperm plasma. In spermatozoa, high content of reduced glutathione (GTH) was recorded, which was more than 3 times higher than in the seminal fluid. The main antioxidants of spermatozoa were superoxide dismutase (SOD), CP, SH-groups of proteins, and reduced content of GTH. We revealed that CAT is a key enzyme that neutralizes excess hydrogen peroxide in boar semen. In contrast, in sperm, hydrogen peroxide was inactivated mainly by GPX. Further research on the mechanisms of action of reactive oxygen species on boar semen will help to develop effective methods for sperm storage and successful fertilization of oocytes.

Association between genetic variants in oxidative stress-related genes and osteoporotic bone fracture. The Hortega follow-up study

The most widely accepted etiopathogenesis hypothesis of the origin of osteoporosis and its complications is that they are a consequence of bone aging and other environmental factors, together with a genetic predisposition. Evidence suggests that oxidative stress is crucial in bone pathologies associated with aging. The aim of this study was to determine whether genetic variants in oxidative stress-related genes modified the risk of osteoporotic fracture. We analysed 221 patients and 354 controls from the HORTEGA sample after 12-14 years of follow up. We studied the genotypic and allelic distribution of 53 SNPs in 24 genes involved in oxidative stress. The results showed that being a carrier of the variant allele of the SNP rs4077561 within TXNRD1 was the principal genetic risk factor associated with osteoporotic fracture and that variant allele of the rs1805754 M6PR, rs4964779 TXNRD1, rs406113 GPX6, rs2281082 TXN2 and rs974334 GPX6 polymorphisms are important genetic risk factors for fracture. This study provides information on the genetic factors associated with oxidative stress which are involved in the risk of osteoporotic fracture and reinforces the hypothesis that genetic factors are crucial in the etiopathogenesis of osteoporosis and its complications.

An Assessment of GPX1 (rs1050450), DIO2 (rs225014) and SEPP1 (rs7579) Gene Polymorphisms in Women with Endometrial Cancer

Background: Numerous studies indicate a relationship between the presence of GPX1 (rs1050450), DIO2 (rs225014) and SEPP1 (rs7579) gene polymorphisms and the development of chronic or neoplastic diseases. However, there are no reports on the influence of these polymorphisms on the development of endometrial cancer. Methods: 543 women participated in the study. The study group consisted of 269 patients with diagnosed endometrial cancer. The control group consisted of 274 healthy women. Blood samples were drawn from all the participants. The PCR-RFLP method was used to determine polymorphisms in the DIO2 (rs225014) and GPX1 (rs1050450) genes. The analysis of polymorphisms in the SEPP1 (rs7579) gene was performed by means of TaqMan probes. Results: There was a 1.99-fold higher risk of developing endometrial cancer in CC homozygotes, DIO2 (rs225014) polymorphism (95% Cl 1.14–3.53, p = 0.017), compared to TT homozygotes. There was no correlation between the occurrence of GPX1 (rs1050450) and SEPP1 (rs7579) polymorphisms and endometrial cancer. Conclusion: Carriers of the DIO2 (rs225014) polymorphism may be predisposed to the development of endometrial cancer. Further research confirming this relationship is recommended.

Association of allelic combinations in selenoprotein and redox related genes with markers of lipid metabolism and oxidative stress - multimarkers analysis in a cross-sectional study

BACKGROUND

Selenium (Se) and selenoproteins have been shown to be involved in lipid metabolism mainly due to their ability to modulate redox homeostasis in adipose tissue. The underlying mechanisms are yet to be evaluated. In the light of few data related to the association between polymorphic variants of selenoprotein encoding genes and metabolic syndrome or obesity in humans, the role of selenoprotein polymorphisms in lipid metabolism remains unclear. The aim of this study was to investigate the impact of allelic combination within selenoprotein and redox related genes on the markers of lipid metabolism and oxidative stress.

METHODS

The study comprised 441 healthy individuals from Poland, in the 18-74 year age group. Allelic combinations were investigated within the polymorphic variants of four selenoprotein encoding genes (GPX1 rs1050450, GPX4 rs713041, SELENOP rs3877899 and SELENOF rs5859) and the redox related gene (SOD2 rs4880). The impact of the most common allelic GPX1-GPX4-SELENOP-SELENOF-SOD2 combinations was assessed on the following markers: triglycerides (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), glutathione peroxidase activities (GPX1, GPX3), lipid peroxidation (as TBARS), ceruloplasmin (Cp) and superoxide dismutase 1 (SOD1).

RESULTS

Multivariable analysis revealed significant associations between three allelic combinations and markers of lipid metabolism, including HDL-C and TC/HDL-C ratio (AAAAa), LDL-C (aaAaa), and triglycerides (aaaaA), whereas two allelic combinations (aAaAA, aaaAA) were associated with GPX3 activity.

CONCLUSION

This study confirms the possible implication of selenoproteins in lipid metabolism and warrants further research on specific allele combinations within selenoprotein and redox related genes in order to identify functional genetic combinations linked to metabolic phenotype.

Vitamin D3 supplementation alleviates chemically-induced cirrhosis-associated hepatocarcinogenesis

Vitamin D₃ (VD₃) deficiency has been associated with increased risk for cirrhosis and hepatocellular carcinoma, a highly incident malignant neoplasia worldwide. On the other hand, VD₃ supplementation has shown some beneficial effects in clinical studies and rodent models of chronic liver disease. However, preventive effects of dietary VD₃ supplementation in cirrhosis-associated hepatocarcinogenesis is still unknow. To investigate this purpose, male Wistar rats submitted to a combined diethylnitrosamine- and thioacetamide-induced model were concomitantly supplemented with VD₃ (5,000 and 10,000 IU/kg diet) for 25 weeks. Liver samples were collected for histological, biochemical and molecular analysis. Serum samples were used to measure 25-hydroxyvitamin D [25(OH)D] and alanine aminotransferase levels. Both VD₃ interventions decreased hepatic collagen deposition and pro-inflammatory p65 protein levels, while increased hepatic antioxidant catalase and glutathione peroxidase activities and serum 25(OH)D, without a clear dose-response effect. Nonetheless, only the highest concentration of VD₃ increased hepatic protein levels of VD receptor, while decreased the number of large preneoplastic glutathione-S-transferase- (>0.5 mm²) and keratin 8/18-positive lesions, as well the multiplicity of hepatocellular adenomas. Moreover, this intervention increased hepatic antioxidant Nrf2 protein levels and glutathione-S-transferase activity. In summary, dietary VD₃ supplementation - in special the highest intervention - showed antifibrotic and antineoplastic properties in chemically-induced cirrhosis-associated hepatocarcinogenesis. The positive modulation of Nrf2 antioxidant axis may be mechanistically involved with these beneficial effects, and may guide future clinical studies.

IRON-MEDIATED EPIGENETIC ACTIVATION OF NRF2 TARGETS

The toxic effects of excess dietary iron within the colonic lumen are well documented, particularly in the context of Inflammatory Bowel Disease (IBD) and Colorectal Cancer (CRC). Proposed mechanisms that underpin iron-associated intestinal disease include: i) the pro-inflammatory and ROS-promoting nature of iron, ii) gene-expression alterations, and iii) intestinal microbial dysbiosis. However, to date no studies have examined the effect of iron on the colonic epigenome. Here we demonstrate that chronic iron exposure of colonocytes leads to significant hypomethylation of the epigenome. Bioinformatic analysis highlights a significant epigenetic effect on NRF2 (nuclear factor erythroid 2-related factor 2) pathway targets (including NAD(P)H Quinone Dehydrogenase 1 [NQO1] and Glutathione peroxidase 2 [GPX2]); this demethylating effect was validated and subsequent gene and protein expression quantified. These epigenetic modifications were not observed upon the diminishment of cellular lipid peroxidation with endogenous glutathione and the subsequent removal of iron. Additionally, the induction of TET1 expression was found post-iron treatment, highlighting the possibility of an oxidative-stress induction of TET1 and subsequent hypomethylation of NRF2 targets. In addition, a strong time dependence on the establishment of iron-orchestrated hypomethylation was found which was concurrent with the increase in the intracellular labile iron pool (LIP) and lipid peroxidation levels. These epigenetic changes were further validated in murine intestinal mucosa in models administered a chronic iron diet, providing evidence for the likelihood of dietary-iron mediated epigenetic alterations in vivo. Furthermore, significant correlations were found between NQO1 and GPX2 demethylation and human intestinal tissue iron-status, thus suggesting that these iron-mediated epigenetic modifications are likely in iron-replete enterocytes. Together, these data describe a novel mechanism by which excess dietary iron is able to alter the intestinal phenotype, which could have implications in iron-mediated intestinal disease and the regulation of ferroptosis.

Risk-focused differences in molecular processes implicated in SARS-CoV-2 infection: corollaries in DNA methylation and gene expression

BACKGROUND

Understanding the molecular basis of susceptibility factors to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a global health imperative. It is well-established that males are more likely to acquire SARS-CoV-2 infection and exhibit more severe outcomes. Similarly, exposure to air pollutants and pre-existing respiratory chronic conditions, such as asthma and chronic obstructive respiratory disease (COPD) confer an increased risk to coronavirus disease 2019 (COVID-19).

METHODS

We investigated molecular patterns associated with risk factors in 398 candidate genes relevant to COVID-19 biology. To accomplish this, we downloaded DNA methylation and gene expression data sets from publicly available repositories (GEO and GTEx Portal) and utilized data from an empirical controlled human exposure study conducted by our team.

RESULTS

First, we observed sex-biased DNA methylation patterns in autosomal immune genes, such as NLRP2, TLE1, GPX1, and ARRB2 (FDR < 0.05, magnitude of DNA methylation difference Δβ > 0.05). Second, our analysis on the X-linked genes identified sex associated DNA methylation profiles in genes, such as ACE2, CA5B, and HS6ST2 (FDR < 0.05, Δβ > 0.05). These associations were observed across multiple respiratory tissues (lung, nasal epithelia, airway epithelia, and bronchoalveolar lavage) and in whole blood. Some of these genes, such as NLRP2 and CA5B, also exhibited sex-biased gene expression patterns. In addition, we found differential DNA methylation patterns by COVID-19 status for genes, such as NLRP2 and ACE2 in an exploratory analysis of an empirical data set reporting on human COVID-9 infections. Third, we identified modest DNA methylation changes in CpGs associated with PRIM2 and TATDN1 (FDR < 0.1, Δβ > 0.05) in response to particle-depleted diesel exhaust in bronchoalveolar lavage. Finally, we captured a DNA methylation signature associated with COPD diagnosis in a gene involved in nicotine dependence (COMT) (FDR < 0.1, Δβ > 0.05).

CONCLUSION

Our findings on sex differences might be of clinical relevance given that they revealed molecular associations of sex-biased differences in COVID-19. Specifically, our results hinted at a potentially exaggerated immune response in males linked to autosomal genes, such as NLRP2. In contrast, our findings at X-linked loci such as ACE2 suggested a potentially distinct DNA methylation pattern in females that may interact with its mRNA expression and inactivation status. We also found tissue-specific DNA methylation differences in response to particulate exposure potentially capturing a nitrogen dioxide (NO2) effect-a contributor to COVID-19 susceptibility. While we identified a molecular signature associated with COPD, all COPD-affected individuals were smokers, which may either reflect an association with the disease, smoking, or may highlight a compounded effect of these two risk factors in COVID-19. Overall, our findings point towards a molecular basis of variation in susceptibility factors that may partly explain disparities in the risk for SARS-CoV-2 infection.

Genetic parameter estimates for three antioxidant factors in cultured Takifugu rubripes

Genetic parameters of three antioxidant factors, including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), were evaluated in liver samples from 840 Takifugu rubripes individuals from 28 full-sib families. Heritability values of SOD, CAT, and GPX were 0.17, 0.18, and 0.14, respectively, and the full-sib family effect values for these antioxidant factors were 0.46, 0.47, and 0.49, respectively. The ranges of phenotypic and genetic correlations among the three immune factors were 0.748-0.848 and 0.726-0.806, respectively. Considering the low heritability and high full-sib family effect of the three antioxidant indexes, the use of both genome-wide selection and clustered regularly interspaced short palindromic repeats (CRISPR) is promising for genetically improving the three antioxidant indexes in cultured fish. In addition, given positive phenotypic and genetic correlations among the three antioxidant enzymes SOD, CAT and GPX, the antioxidant competence of Takifugu rubripes can be improved by genetically improving these three antioxidant traits via multi-trait integrated breeding technology or indirect selection.

Regulatory functions of ROS dynamics via glutathione metabolism and glutathione peroxidase activity in developing rice zygote

Reactive oxygen species (ROS) play essential roles in plant development and environmental stress responses. In this study, ROS dynamics, the glutathione redox status, the expression and subcellular localization of glutathione peroxidases (GPXs), and the effects of inhibitors of ROS-mediated metabolism were investigated along with fertilization and early zygotic embryogenesis in rice (Oryza sativa). Zygotes and early embryos exhibited developmental arrest upon inhibition of ROS production. Egg cells accumulated high ROS levels, and, after fertilization, intracellular ROS levels progressively declined in zygotes in which de novo expression of GPX1 and 3 was observed through upregulation of the genes. In addition to inhibition of GPX activity, depletion of glutathione impeded early embryonic development and led to failure of the zygote to appropriately decrease H₂ O₂ levels. Moreover, through monitoring of the glutathione redox status, the developing zygotes exhibited a progressive glutathione oxidation, which became extremely delayed under inhibited GPX activity. Our results provide insights into the importance of ROS dynamics, GPX antioxidant activity, and glutathione redox metabolism during zygotic/embryonic development.

Efficacy of ulvan on immune response and immuno-antioxidant gene modulation in Labeo rohita against columnaris disease

This study reports the effect of ulvan enriched diet on the influence of growth, changes in hemato-biochemical indices, improvement of antioxidant system, enhancement of innate-adaptive immunity and modification of immuno-antioxidant genes expression in Labeo rohita against Flavobacterium columnaris. The weight gain (WG) was significantly high (P > 0.05) in unchallenged normal and challenged fish fed with diets enriched with 25 and 50 mg kg^-1 ulvan; the FCR was better (P > 0.05) when fed with 50 mg kg^-1 enriched diet. In normal fish fed with or without ulvan supplementation was noted 100% survival rate (SR). In both groups, the red blood cell (RBC) and while blood cell (WBC) counts increased significantly (P > 0.05) when fed with 50 mg kg^-1 ulvan diet whereas the hemoglobin (Hb) level increased significantly on being fed with 25 and 50 mg kg^-1 ulvan diets. The SOD activity was enhanced significantly in both groups fed with any dose of ulvan diets whereas the MDA and GPx activity increased only with 25 and 50 mg kg^-1 ulvan diets. The phagocytic (PC) activity significantly increased with any enriched diet and control diet groups while the respiratory burst (RB) activity increased only with 50 mg kg^-1 ulvan diet. The alternate complement pathway (ACP), activity of lysozyme (Lyz), and immunoglobuline M (IgM) were better in both groups fed with 50 mg kg^-1 ulvan diet. The SOD and GPx antioxidant gene expression were significantly high in both groups fed with any ulvan diet while the Nrf2 gene expression was high with 50 mg kg^-1 ulvan diet. The IL-1β, TNFα, hepcidin, Lyz, and IgM cytokines or proteins mRNA expression were significant in both groups fed with all ulvan supplement diet whereas the β-2M expression was significant only with 50 mg kg^-1 ulvan diet. The present research indicates that both L. rohita groups fed with 50 mg kg^-1 ulvan diet significantly improved growth, antioxidant system, immune defense system, and immuno-antioxidant related gene expression against F. columnaris.

Ameliorative effects of fisetin in letrozole-induced rat model of polycystic ovary syndrome

BACKGROUND

The present study was conducted to investigate the therapeutic effects of a potent polyphenol, fisetin, on the letrozole-induced rat model of polycystic ovary syndrome (PCOS).

METHODOLOGY

Twenty-four female Wistar rats (42 days old) were divided into four groups: control group (received carboxy methylcellulose (CMC 0.5 %)), PCOS group treated with letrozole (1 mg/kg), fisetin group received same dose of letrozole + fisetin (10 mg/kg), and metformin group received same dose of letrozole + metformin (300 mg/kg). At the end of the experiment, biochemical (glucose, lipid profile) and hormonal (insulin, testosterone, estradiol, and progesterone) parameters were analyzed. Histological examinations of ovaries were also conducted by hematoxylin and eosin (H&E) staining. Real-time polymerase chain reaction (PCR) and western blotting were carried out for cytochrome P450 17A1 (CYP17A1), sirtuin-1 (SIRT1), and 5' AMP-activated protein kinase (AMPK) gene expression in the ovaries. Furthermore, enzymatic activities of antioxidants including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the ovaries were analyzed by colorimetric method.

RESULTS

Letrozole administration resulted in a remarkable abnormality in biochemical and hormonal parameters. Fisetin normalized levels of glucose, lipid profile, homeostatic model assessment for insulin resistance (HOMA-IR), testosterone, estradiol, and progesterone. Moreover, fisetin increased expression levels of SIRT1 and AMPK, and decreased expression level of CYP17A1 in the ovaries. Additionally, fisetin showed protective effect by enhancing antioxidant activities of CAT, SOD, and GPx depleted secondary to induction of PCOS. Fisetin effects were comparable to metformin, as the standard drug used for treatment of PCOS.

CONCLUSION

Our results showed that, fisetin treatment caused significant alleviating effects by restoring PCOS-induced alterations in the key genes involved in energy homeostasis and antioxidant enzymes, suggesting that it may have a key role in combating with PCOS.

Isothiocyanate Iberin inhibits cell proliferation and induces cell apoptosis in the progression of ovarian cancer by mediating ROS accumulation and GPX1 expression

Ovarian cancer (OC) is one of the most common gynecologic malignancies with poor survival rate, and Iberin is a member of isothiocyanate family with anti-tumor activity. However, the role of Iberin in OC development has not been reported yet. In this study, A2780 and OVCAR-3 cells were treated with gradient concentrations of Iberin to investigate the effect of Iberin on OC in vitro. Meanwhile, the in vivo tumorgenesis experiment was performed using female BALB/c nude mice treated with Iberin. Iberin inhibited cell proliferation, induced G2 cell cycle arrest and promoted cell apoptosis in OC cells. Besides, Iberin reduced GSH/GSSG level, enhanced ROS accumulation, and activated MAPK signaling in OC cells. More interestingly, ROS scavenger (NAC) compensated the anti-proliferative and pro-apoptotic effects of Iberin on OC cells, suggesting the involvement of ROS in the regulation of Iberin on OC cell growth. Notably, Iberin induced down-regulation of glutathione peroxidase-1 (GPX1), and over-expression of GPX1 reversed Iberin-mediated alterations in the proliferation, apoptosis and ROS accumulation of OC cells. The in vivo tumorgenesis study further evidenced the protection of Iberin against OC development. Besides, Iberin displayed a synergistic effect on the enhancement of chemo-sensitivity in OC cells. In summary, our study demonstrates the anti-tumor effect of Iberin on OC and its potential as a therapeutic agent against OC in the future.

Anoxia-reoxygenation alters H2O2 efflux and sensitivity of redox centers to copper in heart mitochondria

Mitochondrial reactive oxygen species (ROS) have been implicated in organ damage caused by environmental stressors, prompting studies on the effect of oxygen deprivation and metal exposure on ROS metabolism. However, how anoxia and copper (Cu) jointly influence heart mitochondrial ROS metabolism is not understood. We used rainbow trout heart mitochondria to probe the effects of anoxia-reoxygenation and Cu on hydrogen peroxide (H₂O₂) emission during oxidation of palmitoylcarnitine (PC), succinate, or glutamate-malate. In addition, we examined the influence of anoxia-reoxygenation and Cu on site-specific H₂O₂ emission capacities and key antioxidant enzymes, glutathione peroxidase (GPx) and thioredoxin reductase (TrxR). Results showed that anoxia-reoxygenation suppressed H₂O₂ emission regardless of substrate type or duration of anoxia. Anoxia-reoxygenation reduced mitochondrial sensitivity to Cu during oxidation of succinate or glutamate-malate whereas high Cu concentration additively stimulated H₂O₂ emission in mitochondria oxidizing PC. Prolonged anoxia-reoxygenation stimulated H₂O₂ emission from sites O_F and I_F, inhibited emission from sites I_Q, II_F and III_Qo, and disparately altered the sensitivity of the sites to Cu. Interestingly, anoxia-reoxygenation increased GPx and TrxR activities, more prominently when reoxygenation followed a short duration of anoxia. Cu did not alter GPx but reduced TrxR activity in normoxic and anoxic-reoxygenated mitochondria. Overall, our study revealed potential mechanisms that may reduce oxidative damage associated with anoxia-reoxygenation and Cu exposure in heart mitochondria. The increased and decreased H₂O₂ emission from NADH/NAD⁺ and QH₂/Q isopotential sites, respectively, may represent a balance between H₂O₂ required for oxygen deprivation-induced signaling and prevention of ROS burst associated with anoxia-reoxygenation.

GPX1-associated prognostic signature predicts poor survival in patients with acute myeloid leukemia and involves in immunosuppression

OBJECTIVE

Treatment of acute myeloid leukemia (AML) remains a challenge. It is urgent to understand the microenvironment to improve therapy and prognosis.

METHODS

Bioinformatics methods were used to analyze transcription expression profile of AML patient samples with complete clinical information from UCSC Xena TCGA-AML datasets and validate with GEO datasets. Western blot, qPCR, RNAi and CCK8 assay were used to assay the effect of GPX1 expression on AML cell viability and the expression of genes of interest.

RESULTS

Our analyses revealed that highly expressed GPX1 in AML patients links to unfavorable prognosis. GPX1 expression was positively associated with not only fraction levels of myeloid-derived suppressor cells (MDSCs), monocytes and T cell exhaustion, the expression levels of MDSC markers, MDSC-promoting CCR2 and immune inhibitory checkpoints (TIM3/Gal-9, SIRPα and VISTA), but also negatively with low fraction levels of CD4+ and CD8+ T cells. Silencing GPX1 expression reduced AML cell viability and CCR2 expression. Moreover, GPX1-targetd kinases were PKC family, SRC family, SYK and PAK1, which promote AML progression and the resistance to therapy. Furthermore, Additionally, GPX1-associated prognostic signature (GPS) is an independent risk factor with high area under curve (AUC) values of receiver operating characteristic (ROC) curves. High risk group based on GPS enriched not only with endocytosis which transfers mitochondria to favor AML cell survival in response to chemotherapy, but also NOTCH, WNT and TLR signaling which promote therapy resistance.

CONCLUSION

Our results revealed the significant involvement of GPX1 in AML immunosuppression via and provided a prognostic signature for AML patients.

Effects of ethanolic extracts of Quercus, Cirsium vulgare, and Falcaria vulgaris on gastric ulcer, antioxidant and inflammatory indices, and gene expression in rats

INTRODUCTION

Gastric ulcer is a multifaceted process and is usually caused by mucosal damage. Herbal medicines have received much attention considering the side effects of chemical drugs. Nowadays, the use of herbal medicines has received much attention considering the side effects of chemical drugs. Quercus brantii Lindl, Cirsium vulgare (Savi) Ten, and Falcaria vulgaris Bernh are plants used as traditional phytomedicine for gastric ulcer diseases.

AIM OF THE STUDY

This study was aimed to investigate the protective effects of hydroalcoholic extracts of these herbs on ethanol-induced gastric ulceration, in addition, to investigate the antioxidant, anti-inflammatory, and gene expression.

MATERIALS AND METHODS

Thirty Sprague Dawley rats, (200-250 g), were divided into six groups: Control: intact animals; sham: gavaged with distilled water (14 days); negative control: gavaged with 20 mg/kg of omeprazole (14 days); experimental groups I, II, and III: gavaged with 500 mg/kg of the extract of Falcaria vulgaris, Quercus brantii, and Cirsium vulgare, respectively, (14 days). The number of ulcers and pathological parameters were assessed. The serum superoxide dismutase, catalase, glutathione peroxidase, malondialdehyde, total antioxidant capacity, albumin, total protein, haptoglobin, alpha-1-acid glycoprotein, total globulin, alpha-2-macroglobulin, C-fos, C-myc, and Caspase-9 were measured by ELISA and RT-PCR.

RESULTS

The extracts significantly reduced gastric ulcer (52.33%). The results showed that the Quercus brantii extract was more effective. There were significant differences between the serum levels of alpha-1-acid glycoprotein and those of alpha-2-macroglobulin. Also, there was a significant difference in the serum level of antioxidant parameters. Changes in the expression of the genes also confirmed the results suggested by other parameters. The expression levels of C-fos, C-myc, and caspase-9 were decreased, but the Bcl-2 expression increased.

CONCLUSION

The hydro-alcoholic extracts revealed various protection and noticeable change in the expression of caspase-9, C-myc, C-fos, and Bcl-2 genes in rats.

Dose-dependent co-infection of Argulus sp. and Aeromonas hydrophila in goldfish (Carassius auratus) modulates innate immune response and antioxidative stress enzymes

Co-infection with parasites and bacteria is of frequent occurrence in aquaculture, leads to growth impedance otherwise mortality in fish depending on the varying degree of a load of primary pathogen either parasite or bacteria. The mechanistic regulation of immune response during co-infection in fish has merely documented. The aim of this study was to determine the impact of co-infection with Aeromonas hydrophila at three exposure doses of Argulus sp. on the innate immune responses and antioxidative stress enzymes of goldfish (Carassius auratus). The experimental fish were randomly distributed into eight treatment groups viz. T1 (control group without Argulus and A. hydrophila infection), T2 (fish exposed to a sub-lethal dose of A. hydrophila), T3 (low Argulus-infested fish), T4 (T3 + sub-lethal dose of A. hydrophila), T5 (moderate Argulus-infested fish), T6 (T5 + sub-lethal dose of A. hydrophila), T7 (high Argulus-infested fish) and T8 (T7+ sub-lethal dose of A. hydrophila) in duplicates. After distributing experimental fish into their respective treatment group, A. hydrophila was injected to T2, T4, T6 and T8. After the bacterial challenge, four fish from each experimental group were randomly sampled on 24, 72, and 168 h and subjected to the hematological, innate immune parameters and enzymatic analysis. In the co-infection group T8, a high degree of enhanced pathogenicity of A. hydrophila was noticed with increased mortalities (84.2%) in comparison to other groups. The current study shows a declining pattern in RBC, PCV and Hb values with the degree of parasite infestation without co-infection groups. Moreover, in the T8 group, exposure of a sub-lethal dose of bacteria resulted in a drastic reduction of the recorded parameters. Furthermore, a decreased value for WBC, monocyte and neutrophil was found in higher parasite group co-infected with a sub-lethal dose of bacteria relative to other co-infected groups during the experimental period. Also, a decrease in innate immune parameters and antioxidative stress enzymes were observed in the T8 group compared to T7 and T2 groups throughout the trial period. These findings indicate that a rise in the dose of Argulus infection improves A. hydrophila colonization in goldfish and contributes to suppression of the innate immune system and increased mortality.

Biochemical and molecular responses of the Mediterranean mussel (Mytilus galloprovincialis) to short-term exposure to three commonly prescribed drugs

Pharmaceuticals represent a group of emerging contaminants. The short-term effect (3 and 7 days) of warfarin (1 and 10 mg L^-1), dexamethasone (0.392 and 3.92 mg L^-1) and imidazole (0.013 and 0.13 mg L^-1) exposure was evaluated on mussels (Mytilus galloprovincialis). Total antioxidant status, glutathione reductase, glutathione peroxidase (GPx) and superoxide dismutase enzyme activities, and the expression of genes involved in the xenobiotic response (ATP binding cassette subfamily B member 1 (abcb1) and several nuclear receptor family J (nr1j) isoforms), were evaluated. All nr1j isoforms are suggested to be the xenobiotic receptor orthologs of the NR1I family. All drugs increased GPx activity and altered the expression of particular nr1j isoforms. Dexamethasone exposure also decreased abcb1 expression. These findings raised some concerns regarding the release of these pharmaceuticals into the aquatic environment. Thus, further studies might be needed to perform an accurate environmental risk assessment of these 3 poorly studied drugs.

Water and alcohol extracts from Diaphragma juglandis on anti-fatigue and antioxidative effects in vitro and vivo

BACKGROUND

To estimate the anti-fatigue and antioxidative effects of water and alcohol extracts from Diaphragma juglandis (DJ), H₂ O₂ -treated HepG2 cells were used as an in vitro model to determine the total antioxidant capacities of these two extracts, and behavioral tests on mice and biochemical assay were performed via in vivo experiments.

RESULTS

The results indicate that both extracts possess remarkable HepG2 protective capacities and were capable of scavenging 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) similar to vitamin C. Furthermore, they could significantly prolong the bar climbing time and force swimming time, as well as decrease the serum urea nitrogen and increase the lactate dehydrogenase level and glycogen content. These extracts could also improve the activities of total antioxidant capacity, malondialdehyde, superoxide dismutase, catalase and glutathione peroxidase.

CONCLUSION

In conclusion, both water and alcohol extracts from DJ showed good performance with respect to anti-fatigue and could be a potential antioxidant additive in the field of functional foods. © 2020 Society of Chemical Industry.

Melatonin, Its Beneficial Effects on Embryogenesis from Mitigating Oxidative Stress to Regulating Gene Expression

Embryogenesis is a complex multi-stage process regulated by various signaling molecules including pineal and extrapineal melatonin (MT). Extrapineal MT is found in the placenta and ovaries, where it carries out local hormonal regulation. MT is necessary for normal development of oocytes, fertilization and subsequent development of human, animal and avian embryos. This review discusses the role of MT as a regulator of preimplantation development of the embryo and its implantation into endometrial tissue, followed by histo-, morpho- and organogenesis. MT possesses pronounced antioxidant properties and helps to protect the embryo from oxidative stress by regulating the expression of the NFE2L2, SOD1, and GPX1 genes. MT activates the expression of the ErbB1, ErbB4, GJA1, POU5F1, and Nanog genes which are necessary for embryo implantation and blastocyst growth. MT induces the expression of vascular endothelial growth factor (VEGF) and its type 1 receptor (VEGF-R1) in the ovaries, activating angiogenesis. Given the increased difficulties in successful fertilization and embryogenesis with age, it is of note that MT slows down ovarian aging by increasing the transcription of sirtuins. MT administration to patients suffering from infertility demonstrates an increase in the effectiveness of in vitro fertilization. Thus, MT may be viewed as a key factor in embryogenesis regulation, including having utility in the management of infertility.

Transcriptome investigation of anti-inflammation and immuno-regulation mechanism of taurochenodeoxycholic acid

BACKGROUND

Taurochenodeoxycholic acid (TCDCA) is one of the major active components in bile acid. It was proven to have inhibitory activities on inflammation and also participate in host immuno-regulation. TCDCA exerts anti-inflammatory and immuno-regulatory effects through the glucocorticoid receptor (GR) mediated genomic signaling pathway and the G protein-coupled bile acid receptor 5 (TGR5) mediated AC-cAMP-PKA signaling pathway. However, it is unclear whether GR or TGR5 plays an important role in the regulatory effects of TCDCA. In order to further investigate this effects mechanism of TCDCA, the research use the transcriptome to identify the major genes and pathway in the anti-inflammatory and immuno-regulatory effects.

METHODS

After the Fibroblast-like synoviocytes (FLS) being treated by different concentrations (10- 5, 10- 6 and 10- 7 M) of TCDCA for 12 h, the resulting mRNA was analyzed by RNA-seq. The differentially expressed genes were screened from sequencing results using bioinformatics techniques. In the next step, other published literature were referred in order to find out whether those genes mentioned above are related to inflammation. The final selected differentially expressed genes associated with inflammation were then validated by q-PCR and western blot assays.

RESULTS

Five genes associated with anti-inflammatory and immuno-regulatory effects, include Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Glutathione peroxidase 3 (GPX3), Serine/arginine-rich splicing factor-9 (SRSF9), Connective tissue growth factor (CTGF) and Cystatin B (CSTB) were identified. TCDCA at the concentrations of 10- 5, 10- 6 and 10- 7 M significantly (p < 0.05) up-regulate the mRNA and protein expression of SRSF9 and GPX3 and also up-regulate the mRNA expression of CSTB, CTGF and GAPDH. RNA-seq results of GPX3 and SRSF9 expression were consistent with q-PCR results, while q-PCR results of CTGF, GAPDH showed inconsistent with their RNA-seq results. Q-PCR result of CSTB expression also showed inconsistent with the RNA-seq result.

CONCLUSIONS

The anti-inflammatory and immuno-regulatory activities of TCDCA are proven to be related to the up-regulation expression of GPX3, SRSF9 and CSTB.

Ethnically biased microsatellites contribute to differential gene expression and glutathione metabolism in Africans and Europeans

Approximately three percent of the human genome is occupied by microsatellites: a type of short tandem repeat (STR). Microsatellites have well established effects on (a) the genetic structure of diverse human populations and (b) expression of nearby genes. These lines of inquiry have uncovered 3,984 ethnically biased microsatellite loci (EBML) and 28,375 expression STRs (eSTRs), respectively. We hypothesize that a combination of EBML, eSTRs, and gene expression data (RNA-seq) can be used to show that microsatellites contribute to differential gene expression and phenotype in human populations. In fact, our previous study demonstrated a degree of mutual overlap between EBML and eSTRs but fell short of quantifying effects on gene expression. The present work aims to narrow the gap. First, we identify 313 overlapping EBML/eSTRs and recapitulate their mutual overlap. The 313 EBML/eSTRs are then characterized across ethnicity and tissue type. We use RNA-seq data to pursue validation of 49 regions that affect whole blood gene expression; 32 out of 54 affected genes are differentially expressed in Africans and Europeans. We quantify the relative contribution of these 32 genes to differential expression; fold change tends to be less than other differentially expressed genes. Repeat length correlates with expression for 15 of the 32 genes; two are conspicuously involved in glutathione metabolism. Finally, we repurpose a mathematical model of glutathione metabolism to investigate how a single polymorphic microsatellite affects phenotype. We conclude with a testable prediction that microsatellite polymorphisms affect GPX7 expression and oxidative stress in Africans and Europeans.

Structural characterization and antioxidant activity of an acetylated Cyclocarya paliurus polysaccharide (Ac-CPP0.1)

The aim of this study was to investigate the primary structure of an acetylated Cyclocarya paliurus polysaccharide (Ac-CPP_0.1) and its protective effect on H₂O₂-treated dendritic cells. The backbone of Ac-CPP_0.1 was →3)-β-D-Galp-(1→, with some branches α-L-Araf-(1→ residues at O-6 and O-5, β-D-Galp-(1→ and 3,5,6)-β-D-Galf-(1 residues at O-4 and acetyl groups were substituted at the O-2 and O-6 positions of 3)-β-D-Galp-(1 residues. The CPP_0.1 and Ac-CPP_0.1 significantly increased the levels of superoxide dismutase, glutathione peroxidase and catalase on H₂O₂-treated dendritic cells. Meanwhile, both CPP_0.1 and Ac-CPP_0.1 up-regulated the expression of Nrf2 (NF-E2-related factor 2) and down-regulated the Keap1 (Kelch-like ECH-associated protein-1), but Ac-CPP_0.1 had a better effect on antioxidant capacity. These results indicated that potential application of Ac-CPP_0.1 as an antioxidant agent.

Vm-milR37 contributes to pathogenicity by regulating glutathione peroxidase gene VmGP in Valsa mali

MicroRNAs play important roles in various biological processes by regulating their corresponding target genes. However, the function and regulatory mechanism of fungal microRNA-like RNAs (milRNAs) are still largely unknown. In this study, a milRNA (Vm-milR37) was isolated and identified from Valsa mali, which causes the most serious disease on the trunk of apple trees in China. Based on the results of deep sequencing and quantitative reverse transcription PCR, Vm-milR37 was found to be expressed in the mycelium, while it was not expressed during the V. mali infection process. Overexpression of Vm-milR37 did not affect vegetative growth, but significantly decreased pathogenicity. Based on degradome sequencing, the target of Vm-milR37 was identified as VmGP, a glutathione peroxidase. The expression of Vm-milR37 and VmGP showed a divergent trend in V. mali-apple interaction samples and Vm-milR37 overexpression transformants. The expression of VmGP could be suppressed significantly by Vm-milR37 when coexpressed in tobacco leaves. Deletion of VmGP showed significantly reduced pathogenicity compared with the wild type. VmGP deletion mutants showed more sensitivity to hydrogen peroxide. Apple leaves inoculated with Vm-milR37 overexpression transformants and VmGP deletion mutant displayed increased accumulation of reactive oxygen species compared with the wild type. Thus, Vm-milR37 plays a critical role in pathogenicity by regulating VmGP, which contributes to the oxidative stress response during V. mali infection. These results provide important evidence to define the roles of milRNAs and their corresponding target genes in pathogenicity.

The comparison of pro- and antioxidative parameters in plasma and placental tissues during early phase of placental development in cows

Physiological balance between pro- and antioxidative processes is crucial for placentation and further development of fetus and placenta. Parameters of pro- and antioxidative profile may serve as markers of proper course of pregnancy. The aim of study was to assess whether the balance between pro- and antioxidative parameters during placentation phase in bovine placenta is maintained. Placental and blood samples were collected from healthy, HF, pregnant (2nd-3rd month) cows (n = 8) in slaughterhouse and in farm, respectively. Formylokinurenine and bityrosine content were measured spectrofluorimetrically in blood plasma and tissue homogenates while metabolites of lipid peroxidation, total antioxidant capacity, SH groups and activity of antioxidative enzymes (glutathione peroxidase and superoxide dismutase) were determined in examined tissues by spectrophotometry. Western blotting was used to confirm the presence of enzymatic proteins in placenta. Results: Local profile in tissues was more pronounced than general profile in blood plasma. Activities of antioxidative enzymes were significantly (p < 0.05) higher in 2nd compared to 3rd month of pregnancy in maternal part of placenta while prooxidant parameters showed opposite relationship. Obtained results showed significant differences when compared to data from non-pregnant animals or time of parturition. Further studies are necessary for elucidation of placentation phase in cows.

Construction of a Vibrio anguillarum flagellin B mutant and analysis of its immuno-stimulation effects on Macrobrachium rosenbergii

Vibrio anguillarum is a globally distributed aquatic pathogen, and its flagellin B (FlaB) protein can evoke innate immune responses in hosts. In order to explore the role of FlaB in V. anguillarum infection, we constructed a FlaB-deficient mutant using overlapping PCR and two-step homologous recombination, and gene sequencing confirmed successful knockout of the FlaB gene. Scanning electron microscopy showed no significant differences in the morphological structure of the flagellum between wild-type and FlaB-deficient strains. The mutant was subsequently injected into the freshwater prawn (Macrobrachium rosenbergii) to explore its pathogenicity in the host, and expression of myeloid differentiation factor 88, prophenoloxidase, catalase, superoxide dismutase and glutathione peroxidase was investigated by real-time PCR. The results showed that deletion of FlaB had little effect on V. anguillarum-induced expression of these immune-related genes (p > 0.05). In general, the FlaB mutant displayed similar flagella morphology and immune characteristics to the wild-type strain, hence we speculated that knockout of FlaB might promote the expression and function of other flagellin proteins. Furthermore, this study provides a rapid and simple method for obtaining stable mutants of V. anguillarum free from foreign plasmid DNA.

Genetic variations of three important antioxidative enzymes SOD2, CAT, and GPX1 in nonalcoholic steatohepatitis

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is closely related to reactive oxygen species (ROS). Superoxide anion radicals, the main product of ROS, can be reduced by manganese superoxide dismutase (SOD2) to hydrogen peroxide, which is further reduced by catalase (CAT) and glutathione peroxidase (GPX) to water. We aimed to investigate the association between the most important genetic variants of SOD2, CAT, and GPX1 and susceptibility to NASH.

METHODS

A total of 126 adults with liver tissue-verified NASH, 56 patients with liver tissue-verified nonalcoholic fatty liver (NAFL), and 153 healthy controls were enrolled. Their DNA profiles were retrieved for genotype assessment of SOD2 47T>C (rs4880), CAT -262C>T (rs1001179), and GPX1 593C>T (rs1050450) variation.

RESULTS

There were statistical differences between the SOD2 and CAT genotypes across the NASH, NAFL, and control groups, but not GPX1. The NASH group had a significantly higher frequency of subjects with SOD2 C allele (38.8%) compared with the NASL group (25.0%) and the controls (22.9%, p = 0.010). Similarly, the NASH group had a significantly higher percentage of subjects with CAT T allele (23.0%) compared with the NAFL group (10.7%) and the controls (7.2%, p = 0.001). For subjects with both the SOD2 C allele and CAT T allele, 88.2% were in the NASH group. After adjusting for confounders, the CAT mutant T allele and SOD2 mutant C allele were still the highest independent risk factors for NASH (odds ratio [OR] 3.10 and 2.36, respectively). In addition, there was a synergistic effect for those two alleles and the occurrence of NASH with an adjusted OR of 8.57 (p = 0.030).

CONCLUSION

The genetic variations of CAT and SOD2 may increase the risk of NASH, which may aid in the screening of patients who are at high risk of NASH, and offer a potential anti-oxidant targeting route for the treatment of NASH.

Nano-selenium Supplementation Increases Selenoprotein (Sel) Gene Expression Profiles and Milk Selenium Concentration in Lactating Dairy Cows

Supplementation with selenium is common for dairy cows, but the importance of selenium source is not clear. This study aimed to compare nano-selenium (Nano-Se) and sodium selenite supplements for dairy cows on lactation performance, milk Se levels and selenoprotein (Sel) gene expression. Twelve multiparous Holstein cows were randomly divided into two groups: a control group fed a basal diet plus 0.30 mg Se/kg of DM as sodium selenite or Nano-Se for 30 days. Dry matter intake, milk yield and composition were not affected by dietary Se source (P > 0.05); however, the milk total Se levels and milk glutathione peroxidase (GSH-Px) activities were higher with Nano-Se supplementation than sodium selenite (P < 0.05). At the end of the experiment, Nano-Se supplementation significantly increased plasma Se levels and GSH-Px activity, compared with the sodium selenite supplement. The mRNA expression levels of glutathione peroxidase 1, 2 and 4; thioredoxin reductase 2 and 3; and selenoproteins W, T, K and F were markedly upregulated (P < 0.05) in the mammary gland of the Nano-Se group. Thus, the source of selenium plays an important role in the antioxidant status and in particular the Sel gene expression in the mammary glands of dairy cows, both being stimulated by nano sources.

Dietary Serine Supplementation Regulates Selenoprotein Transcription and Selenoenzyme Activity in Pigs

The synthesis of selenocysteine and its incorporation into selenoproteins require serine during the action of seryl-tRNA synthetase. In view of this, we conducted this study to explore the effects of dietary serine supplementation on selenoprotein transcription and selenoenzyme activity in pigs. A total of 35 crossbred barrows (28 days old) were randomly assigned to five treatment groups. During the 42-day growth experiment, pigs were fed either a basal diet with no supplemented serine or diets supplemented with 0.25%, 0.5%, 0.75%, or 1% serine. The results showed that serine supplementation had no effect on the selenium content in the serum, skeletal muscle, and kidney of pigs. However, dietary supplementation with 0.5% serine significantly increased the selenium content in the liver. Diets supplemented with different levels of serine significantly increased the gene expression of glutathione peroxidase 1 (Gpx1), Gpx2, thioredoxin reductase 1 (Txnrd1), Txnrd2, and selenoprotein P (Sepp1) in the skeletal muscle and liver of pigs. Moreover, pigs supplemented with 0.5% serine had the highest selenoprotein P concentration and glutathione peroxidase (GPx) and thioredoxin reductase (TrxR) activities in the skeletal muscle, which were significantly higher than those in the control pigs. Additionally, pigs supplemented with 0.25% serine had the highest GPx and TrxR activities in the liver, which were significantly higher than those in the control pigs. In conclusion, dietary serine supplementation could improve selenoprotein transcription and selenoenzyme activity in pigs, with the appropriate concentrations of serine to be included in the diet being 0.25% or 0.5%.

Tissue-Biased and Species-Specific Regulation of Glutathione Peroxidase (GPx) Genes in Scallops Exposed to Toxic Dinoflagellates

Marine bivalves could accumulate paralytic shellfish toxins (PSTs) produced by toxic microalgae, which might induce oxidative stress. Glutathione peroxidases (GPxs) are key enzymes functioning in the antioxidant defense, whereas our understanding of their roles in PST challenge in bivalves is limited. Herein, through genome-wide screening, we identified nine (CfGPx) and eight (PyGPx) GPx genes in Zhikong scallop (Chlamys farreri) and Yesso scallop (Patinopecten yessoensis), respectively, and revealed the expansion of GPx3 sub-family in both species. RNA-Seq analysis revealed high expression of scallop GPx3s after D stage larva during early development, and in adult hepatopancreas. However, in scallops exposed to PST-producing dinoflagellates, no GPx was significantly induced in the hepatopancreas. In scallop kidneys where PSTs were transformed to higher toxic analogs, most CfGPxs were up-regulated, with CfGPx3s being acutely and chronically induced by Alexandrium minutum and A. catenella exposure, respectively, but only one PyGPx from GPx3 subfamily was up-regulated by A. catenella exposure. Our results suggest the function of scallop GPxs in protecting kidneys against the oxidative stresses by PST accumulation or transformation. The tissue-, species-, and toxin-dependent expression pattern of scallop GPxs also implied their functional diversity in response to toxin exposure.

Melatonin protects against oxybenzone-induced deterioration of mouse oocytes during maturation

Oxybenzone (OBZ), an ultraviolet light filter that is widely used in sunscreens and cosmetics, is an emerging contaminant found in humans and the environment. Recent studies have shown that OBZ has been detected in women's plasma, urine, and breast milk. However, the effects of OBZ exposure on oocyte meiosis have not been addressed. In this study, we investigated the detrimental effects of OBZ on oocyte maturation and the protective roles of melatonin (MT) in OBZ-exposed mouse models. Our in vitro and in vivo results showed that OBZ suppressed oocyte maturation, while MT attenuated the meiotic defects induced by OBZ. In addition, OBZ facilitated H3K4 demethylation by increasing the expression of the Kdm5 family of genes, elevating ROS levels, decreasing GSH, impairing mitochondrial quality, and disrupting spindle configuration in oocytes. However, MT treatment resulted in significant protection against OBZ-induced damage during oocyte maturation and improved oocyte quality. The mechanisms underlying the beneficial roles of MT involved reduction of oxidative stress, inhibition of apoptosis, restoration of abnormal spindle assembly and up-regulation of H3K4me3. Collectively, our results suggest that MT protects against defects induced by OBZ during mouse oocyte maturation in vitro and in vivo.

Alcohol dehydrogenase 1 and NAD(H)-linked methylglyoxal oxidoreductase reciprocally regulate glutathione-dependent enzyme activities in Candida albicans

Glutathione reductase (Glr1) activity controls cellular glutathione and reactive oxygen species (ROS). We previously demonstrated two predominant methylglyoxal scavengers-NAD(H)-linked methylglyoxal oxidoreductase (Mgd1) and alcohol dehydrogenase 1 (Adh1)-in glutathione-depleted γ-glutamyl cysteinyl synthetase-disrupted Candida albicans. However, experimental evidence for Candida pathophysiology lacking the enzyme activities of Mgd1 and Adh1 on glutathione-dependent redox regulation remains unclear. Herein, we have aimed to demonstrate that glutathione-dependent enzyme activities coupled with cellular ROS changes is regulated by methylglyoxal accumulation in Δmgd1/Δadh1 double disruptants. Δmgd1/Δadh1 showed severe growth defects and G1-phase cell cycle arrest. The observed complementary and reciprocal methylglyoxal-oxidizing and methylglyoxalreducing activities between Δmgd1 and Δadh1 were not always exhibited in Δmgd1/Δadh1. Although intracellular accumulation of methylglyoxal and pyruvate was shown in all disruptants, to a greater or lesser degree, methylglyoxal was particularly accumulated in the Δmgd1/Δadh1 double disruptant. While cellular ROS significantly increased in Δmgd1 and Δadh1 as compared to the wild-type, Δmgd1/Δadh1 underwent a decrease in ROS in contrast to Δadh1. Despite the experimental findings underlining the importance of the undergoing unbalanced redox state of Δmgd1/Δadh1, glutathione-independent antioxidative enzyme activities did not change during proliferation and filamentation. Contrary to the significantly lowered glutathione content and Glr1 enzyme activity, the activity staining-based glutathione peroxidase activities concomitantly increased in this mutant. Additionally, the enhanced GLR1 transcript supported our results in Δmgd1/Δadh1, indicating that deficiencies of both Adh1 and Mgd1 activities stimulate specific glutathione-dependent enzyme activities. This suggests that glutathione-dependent redox regulation is evidently linked to C. albicans pathogenicity under the control of methylglyoxal-scavenging activities.

The Effect of Chronic Mild Stress and Escitalopram on the Expression and Methylation Levels of Genes Involved in the Oxidative and Nitrosative Stresses as Well as Tryptophan Catabolites Pathway in the Blood and Brain Structures

Previous studies suggest that depression may be associated with reactive oxygen species overproduction and disorders of the tryptophan catabolites pathway. Moreover, one-third of patients do not respond to conventional pharmacotherapy. Therefore, the study investigates the molecular effect of escitalopram on the expression of Cat, Gpx1/4, Nos1/2, Tph1/2, Ido1, Kmo, and Kynu and promoter methylation in the hippocampus, amygdala, cerebral cortex, and blood of rats exposed to CMS (chronic mild stress). The animals were exposed to CMS for two or seven weeks followed by escitalopram treatment for five weeks. The mRNA and protein expression of the genes were analysed using the TaqMan Gene Expression Assay and Western blotting, while the methylation was determined using methylation-sensitive high-resolution melting. The CMS caused an increase of Gpx1 and Nos1 mRNA expression in the hippocampus, which was normalised by escitalopram administration. Moreover, Tph1 and Tph2 mRNA expression in the cerebral cortex was increased in stressed rats after escitalopram therapy. The methylation status of the Cat promoter was decreased in the hippocampus and cerebral cortex of the rats after escitalopram therapy. The Gpx4 protein levels were decreased following escitalopram compared to the stressed/saline group. It appears that CMS and escitalopram influence the expression and methylation of the studied genes.

Characterization and expression analysis of seven selenoprotein genes in yellow catfish Pelteobagrus fulvidraco to dietary selenium levels

BACKGROUND

Selenium (Se) appears in the selenoproteins in the form of selenocysteine (Sec) and is important for the growth and development of vertebrates. The present study characterized seven selenoproteins, consisting of the GPX1, GPX3, GPX4, SELENOW, SELENOP, TXNRD2 and TXNRD3 cDNAs in various tissues of yellow catfish, explored their regulation to dietary Se addition.

METHODS

3' and 5' RACE PCR were used to clone full-length cDNA sequences of seven selenoprotein genes (GPX1, GPX3, GPX4, SELENOW, SELENOP, TXNRD2 and TXNRD3). Their molecular characterizations were analyzed, including conservative motifs and the SECIS elements. The phylogenetic trees were generated through neighbor-joining (NJ) method with MEGA 6.0 with 1000 bootstrap replications. Quantitative real-time PCR was used to explore their mRNA tissue distribution in the heart, anterior intestine, dorsal muscle, head kidney, gill, liver, brain, spleen and mesenteric fat. Yellow catfish (mixed sex) were fed diets with dietary Se contents at 0.03 (low Se), 0.25 (adequate Se) and 6.39 (high Se) mg Se/kg, respectively, for 12 weeks, and their spleen, kidney, testis and brain were used for the determination of the mRNA levels of the seven selenoproteins.

RESULTS

The seven selenoproteins had similar domains to their corresponding members of other vertebrates. They were widely expressed in nine tissues, including heart, liver, brain, spleen, head kidney, dorsal muscle, mesenteric fat, anterior intestine and gill, but showed tissue-dependent expression patterns. Dietary Se addition affected the expression of the seven genes in spleen, kidney, testis and brain tissues of yellow catfish.

CONCLUSION

Taken together, our study demonstrated the characterization, expression and regulation of seven selenoproteins, which increased our understanding of the biological functions of Se and selenoproteins in fish.

Ameliorative effect of tannic acid on hypermethioninemia-induced oxidative and nitrosative damage in rats: biochemical-based evidences in liver, kidney, brain, and serum

We investigated the ability of tannic acid (TA) to prevent oxidative and nitrosative damage in the brain, liver, kidney, and serum of a rat model of acute hypermethioninemia. Young Wistar rats were divided into four groups: I (control), II (TA 30 mg/kg), III (methionine (Met) 0.4 g/kg + methionine sulfoxide (MetO) 0.1 g/kg), and IV (TA/Met + MetO). Rats in groups II and IV received TA orally for seven days, and rats of groups I and III received an equal volume of water. After pretreatment with TA, rats from groups II and IV received a single subcutaneous injection of Met + MetO, and were euthanized 3 h afterwards. In specific brain structures and the kidneys, we observed that Met + MetO led to increased reactive oxygen species (ROS), nitrite, and lipid peroxidation levels, followed by a reduction in thiol content and antioxidant enzyme activity. On the other hand, pretreatment with TA prevented both oxidative and nitrosative damage. In the serum, Met + MetO caused a decrease in the activity of antioxidant enzymes, which was again prevented by TA pretreatment. In contrast, in the liver, there was a reduction in ROS levels and an increase in total thiol content, which was accompanied by a reduction in catalase and superoxide dismutase activities in the Met + MetO group, and pretreatment with TA was able to prevent only the reduction in catalase activity. Conclusively, pretreatment with TA has proven effective in preventing oxidative and nitrosative changes caused by the administration of Met + MetO, and may thus represent an adjunctive therapeutic approach for treatment of hypermethioninemia.

Dried lemon peel enriched diet improves antioxidant activity, immune response and modulates immuno-antioxidant genes in Labeo rohita against Aeromonas sorbia

The effect of diet enriched with dried lemon (Citrus limon) peel was fed to Labeo rohita at three different levels (0, 1, 2.5, and 5 g kg^-1) for a period of 60 days; the impact of the diet on the hematology, antioxidant activity and immunological reaction and gene expression against Aeromonas sorbia is reported. In both un-challenged and challenged groups treated with 2.5 g and 5 g kg^-1 dried lemon peel diets, the enhanced significant changes are: the weight gain and specific growth rate, white blood cell and total protein content, the antioxidants: superoxide dismutase, catalase, glutathione peroxidase, and glutathione activities, the respiratory burst, alternative complement pathway, complement C3, and total immunoglobulin M levels. Similarly, the heat shock protein-70 and -90, superoxide dismutase, glutathione peroxidase, glutathione, interleukin-1β and -8, tumor necrosis factor alpha, inducible nitric oxide synthase, transforming growth factor beta, and immunoglobulin M were up-regulated significantly. Any dried lemon peel enriched diet increased the phagocytic and lysozyme activities significantly in both groups. In the un-challenged group treated with 0 g kg^-1 diet or in both groups treated with 2.5 g kg^-1 diet the SR was 100%. These results indicate that in both un-challenged and challenged-treated groups the 2.5 and 5 g kg^-1 dried lemon peel enriched diets positively modulate growth rate, physiology, and antioxidant status, innate-adaptive immune response as well as antioxidant and immune related gene expression in L. rohita against A. sorbia.

Glutathione peroxidase-1 knockout potentiates behavioral sensitization induced by cocaine in mice via σ-1 receptor-mediated ERK signaling: A comparison with the case of glutathione peroxidase-1 overexpressing transgenic mice

We demonstrated that the gene of glutathione peroxidase-1 (GPx-1), a major antioxidant enzyme, is a potential protectant against the neurotoxicity and conditioned place preference induced by cocaine. Because the sigma (σ)-1 receptor is implicated in cocaine-induced drug dependence, we investigated whether the GPx-1 gene modulates the σ-1 receptor in the behavioral sensitization induced by cocaine. Cocaine-induced behavioral sensitization was more pronounced in GPx-1 knockout (KO) than wild-type (WT) mice and was less pronounced in GPx-1 overexpressing transgenic (GPx-1 TG) than non-TG mice. Cocaine treatment significantly enhanced the oxidative burden and reduced the GSH levels in the striatum of WT, GPx-1 KO, and non-TG mice but not in that of GPx-1 TG mice. In addition, cocaine significantly increased the nuclear translocation, its DNA binding activity of nuclear factor erythroid-2-related factor 2 (Nrf2) as well as the mRNA expression of γ-glutamylcysteine (GCL). The genetic depletion of GPx-1 inhibited the Nrf2-related glutathione system, whereas the genetic overexpression of GPx-1 activated this system against behavioral sensitization. BD1047, a σ-1 receptor antagonist, and U0126, an ERK inhibitor significantly induced the Nrf2-related antioxidant potential against behavioral sensitization. Unlike BD1047, U0126 did not affect the cocaine-induced σ-1 receptor immunoreactivity, suggesting that the σ-1 receptor is an upstream molecule for ERK signaling. Importantly, BD1047 and U0126 failed to affect the σ-1 receptor immunoreactivity and ERK phosphorylation induced by cocaine in GPx-1 TG mice. Our results suggest that GPx-1 is a critical mediator for the attenuation of cocaine-induced behavioral sensitization via modulating σ-1 receptor-mediated ERK activation by the induction of the Nrf2-related system.