Netrin-1 and clusterin: Innovative potential diagnostic biomarkers for early renal damage in β-thalassemia major children

BACKGROUND

Children with β-thalassemia major (β-TM) suffer from tubular dysfunction even before the onset of any renal impairment symptoms and/or clinical signs. Therefore, identifying innovative biomarkers allowing early renal damage detection has focused attention.

AIM

This study aims to preliminary assess Netrin-1(NTN-1) and clusterin (CLU) in β-TM children and explore their possible roles as surrogate noninvasive biomarkers of renal tubular dysfunction.

SUBJECTS AND METHODS

In this study, 40 β-TM children and 30 healthy children were enrolled. Routine serum and urinary biochemical variables were determined. Urinary NTN-1 and CLU levels were measured using ELISA and their mRNA expression in PBMCs were assayed using real-time PCR. Serum TNF-α, MDA levels and GST activity were measured.

RESULTS

Urinary NTN-1 and CLU concentrations and mRNA relative expression levels in PBMCs were significantly increased in β-TM children relative to controls. Oxidative stress and inflammatory markers revealed significant elevation in β-TM children compared to controls. The change in these parameters correlated significantly with other renal parameters. ROC curves analysis showed that urinary NTN-1 and CLU levels are of promising diagnostic performance.

CONCLUSION

Our results suggest that NTN-1 and CLU are qualified as new noninvasive biomarker panels for early detection of renal injury in β-TM children. Moreover, urinary NTN-1 is recommended as a precise one during the clinical practices.

Influence of genetic polymorphisms in glutathione-S-transferases gene in response to imatinib among Brazilian patients with chronic myeloid leukemia

Polymorphism in metabolizing enzymes can influence drug response as well as the risk for adverse drug reactions. Nevertheless, there are still few studies analyzing the consequence of polymorphisms for the Glutathione-S-transferases (GST) gene to drug response in chronic myeloid leukemia (CML). This study reports, the influence of GSTP1*B and GSTT1/GSTM1null polymorphisms in response to imatinib in CML patients in a Brazilian population. One hundred thirty-nine CML patients from the Clinical Hospital of Goiânia, Goiás, Brazil, treated with imatinib were enrolled in this study. Genotyping of GSTT1 and GSTM1 genes deletions were performed by qPCR and of GSTP1 gene was performed by RFLP-PCR. The frequency of GSTP1*1B, GSTT1 and GSTM1null polymorphisms were determined for all patients. The influence of each patient's genotypes was analyzed with the patient's response to imatinib treatment. Brazilian CML patients revealed GSTT1 and GSTM1 genes deletions. GSTT1 deletion was found in 19.3% of patients and GSTM1 deletion in 48.7% of patients with CML. GSTT1/GSTM1 deletion was found in 11.7% in Brazilian CML patients. The "G allele" of GSTP1*B, is associated with later cytogenetic response in imatinib therapy. While, the gene presence combined with GG genotype (GSTM1 present/GSTPI-GG) conferred a tend to a later cytogenetic response to patients. GSTP1*B and GSTT1/GSTM1null polymorphisms influence treatment response in CML. Brazilian CML patients presenting GSTP1 AA/AG genotypes alone and in combination with GSTT1 null reach the cytogenetic response faster, while patients presenting GSTP1-GG and GSTMI positive genotypes may take longer to achieve cytogenetic response. As a result, it allows a better prognosis, with the use of an alternative therapy, other than reducing treatment cost.

Glutathione S transferase T1 gene polymorphism and its promoter methylation are associated with breast cancer susceptibility in Egyptian women

BACKGROUND

Breast cancer (BC) is one of the leading causes of cancer mortality in women. Glutathione S-transferase (GSTT1) is involved in activation of detoxification reactions and catalysis of chemicals conjugation with glutathione. GSTT1 genotype is a limiting factor for some environmental diseases. Epigenetic changes have an essential role in BC through inappropriate interaction between genomic and environmental risk factors.

AIM

This study was directed to explore the association of BC risk with GSTT1 genetic variations and its methylation status in Egyptian women.

DESIGN AND METHODS

This study included 100 healthy women as the control group and 100 patients were clinically and histologically diagnosed with breast cancer. All blood samples were used for genomic DNA extraction. GSTT1 genotyping was accomplished by multiplex PCR and methylation-specific PCR was used to analyze the GSTT1 promoter methylation status.

RESULTS

Breast cancer patients showed significant incidence of null GSTT1 in relation to controls (p = 0.004). GSTT1 gene promoter methylation status showed significant difference between hypermethylated and unmethylated patients when compared with healthy subjects (p = 0.005). GSTT1 promoter methylation status was not significantly associated with null genotype. There was no significant association between GSTT1-null genotypes and BC stage in cases with or without family history, but for promotor methylation, there was significant association with stage III and IV breast cancer disease.

CONCLUSION

GSTT1 null genetic variant and promoter hypermethylation in the GSTT region of the gene may be considered as critical risk factors for BC in Egyptian women.

An Ixodes scapularis glutathione S-transferase plays a role in cell survival and viability during Langat virus infection of a tick cell line

Ticks are important vectors of diseases affecting both humans and animals. To be an efficient vector, ticks have to survive infection by pathogens such as the Langat virus (LGTV). One method utilized by ticks is their complex antioxidant mechanism. Included in the vast antioxidant processes are several enzymes involved in redox homeostasis. The ubiquitous glutathione S-transferases (GSTs) belong to the antioxidant family of enzymes. In this study, we evaluated the role of a GST during LGTV infection. ISE6 cells were infected with LGTV with a multiplicity of infection (MOI) of 0.01 and observed daily. The infection success was monitored via indirect immunofluorescent antibody test (IFAT) for LGTV for up to 4 days. The gene expression of IsGST1 was determined by real-time polymerase chain reaction (PCR) using IsGST1 gene-specific primers. Knockdown of the IsGST1 gene with subsequent LGTV infection was also performed. Afterward, ISE6 cell mortality and viability were checked daily until the fourth day. The virus titer from supernatants of IsGST1-knockdown cells was quantified using a focus-formation assay. IFAT data showed that LGTV infects ISE6 cells in a time-dependent manner with increasing infection from day 0 to day 4. The IsGST1 genes showed an increasing expression until day 2 of infection, while decreased expression was observed from day 3 to day 4 post-infection. Knockdown of the IsGST1 resulted in increased mortality on the third day of infection, while the cell viability was also negatively affected by the knockdown of the IsGST1 genes from day 0 to day 4 post-infection. Knockdown of the IsGST1 genes also resulted in a decreased viral titer from the supernatants of the ISE6 cells infected with LGTV. Based on the results, GSTs are possibly utilized both by cells and the virus for mutual survival and proliferation.

Sensitivity of Osteosarcoma Cells to Concentration-Dependent Bioactivities of Lipid Peroxidation Product 4-Hydroxynonenal Depend on Their Level of Differentiation

4-Hydroxynonenal (HNE) is a major aldehydic product of lipid peroxidation known to exert several biological effects. Normal and malignant cells of the same origin express different sensitivity to HNE. We used human osteosarcoma cells (HOS) in different stages of differentiation in vitro, showing differences in mitosis, DNA synthesis, and alkaline phosphatase (ALP) staining. Differentiated HOS cells showed decreased proliferation (³H-thymidine incorporation), decreased viability (thiazolyl blue tetrazolium bromide-MTT), and increased apoptosis and necrosis (nuclear morphology by staining with 4′,6-diamidino-2-phenylindole-DAPI). Differentiated HOS also had less expressed c-MYC, but the same amount of c-FOS (immunocytochemistry). When exposed to HNE, differentiated HOS produced more reactive oxygen species (ROS) in comparison with undifferentiated HOS. To clarify this, we measured HNE metabolism by an HPLC method, total glutathione (GSH), oxidized GSH (ox GSH), glutathione transferase activity (GST), proteasomal activity by enzymatic methods, HNE-protein adducts by genuine ELISA and fatty acid composition by GC-MS in these cell cultures. Differentiated HOS cells had less GSH, lower HNE metabolism, increased formation of HNE-protein adducts, and lower proteasomal activity, in comparison to undifferentiated counterpart cells, while GST and oxGSH were the same. Fatty acids analyzed by GC-MS showed that there is an increase in C20:3 in differentiated HOS while the amount of C20:4 remained the same. The results showed that the cellular machinery responsible for protection against toxicity of HNE was less efficient in differentiated HOS cells. Moreover, differentiated HOS cells contained more C20:3 fatty acid, which might make them more sensitive to free radical-initiated oxidative chain reactions and more vulnerable to the effects of reactive aldehydes such as HNE. We propose that HNE might act as natural promotor of decay of malignant (osteosarcoma) cells in case of their differentiation associated with alteration of the lipid metabolism.

Effects of GSTT1 and GSTM1 polymorphisms in glutathione levels and breast cancer development in Brazilian patients

Polymorphisms in the glutathione transferase enzymes (GSTs) genes have been associated with susceptibility to develop breast cancer (BC), but few are known regarding its role on this disease prognosis and impact on antioxidant status. This study evaluated the polymorphisms of GSTM1 and GSTT1 genes and their relationship with BC susceptibility and prognostic, as well as its impact on plasma reduced glutathione (GSH) levels. The present study included 121 women with invasive ductal BC and 151 healthy controls. Polymorphisms analyses were performed using the polymerase chain reaction (PCR) technique and GSH levels were measured with the Ellman's reagent. GSTT1 (OR 1.29; p = 0.39) and GSTM1 (OR 1.03; p = 0.91) polymorphisms did not show any association with BC susceptibility. The mean concentration values in nmol/L of GSH were 20.37 ± 5.82 for patients with null genotypes for both genes, 19.75 ± 3.47 for null GSTT1, 17.22 ± 1.35 for active GSTT1, 18.82 ± 1.96 for absent GSTM1, and 16.59 ± 1.66 for active GSTM1, but no significance was found. Therefore, it can be concluded that the behavior of these polymorphisms concerning BC might be not only related to the absence of enzymatic expression but may also be related to the body's response with its antioxidant mechanisms and it should be further studied.

Protective efficacy of phenoxyacetyl oxazolidine derivatives as safeners against nicosulfuron toxicity in maize

BACKGROUND

Herbicide safeners mitigate crop damage without reducing herbicide efficacy. Here, the protective effects of phenoxyacetyl oxazolidine derivatives as potential safeners were evaluated with a view toward reducing injury caused by sulfonylurea herbicide nicosulfuron to sensitive maize varieties.

RESULTS

Growth indices demonstrated that the bioactivity of compound 9 (N-phenoxyacety-2-methyl-2,4-diethyl-1,3-oxazolidine) was superior to that of R-28725 and all other compounds tested. Compound 9 induced endogenous glutathione and upregulated glutathione-S-transferase (GST) in maize. Thus, it could enhance maize tolerance to nicosulfuron. Compared with the untreated water control group, the maximum reaction rate of GST was increased by 37.62%, while the maximum velocity of GST was decreased by 61.93% after treatment with compound 9. Acetolactate synthase relative activity was significantly enhanced in the case of treatment with compound 9, indicating the excellent protective effects of compound 9 against nicosulfuron in maize.

CONCLUSIONS

The present work demonstrates that phenoxyacetyl oxazolidine derivatives are potentially efficacious as herbicide safeners and merit further investigation.

Mechanism of Resistance to S-metolachlor in Palmer amaranth

Herbicides are major tools for effective weed management. The evolution of resistance to herbicides in weedy species, especially contributed by non-target-site-based resistance (NTSR) is a worrisome issue in crop production globally. Glyphosate-resistant Palmer amaranth (Amaranthus palmeri) is one of the extremely difficult weeds in southern US crop production. In this study, we present the level and molecular basis of resistance to the chloroacetamide herbicide, S-metolachlor, in six field-evolved A. palmeri populations that had survivors at the recommended field-dose (1.1 kg ai ha^-1). These samples were collected in 2014 and 2015. The level of resistance was determined in dose-response assays. The effective dose for 50% control (ED₅₀) of the susceptible population was 27 g ai ha^-1, whereas the ED₅₀ of the resistant populations ranged from 88 to 785 g ai ha^-1. Therefore, A. palmeri resistance to S-metolachlor evolved in Arkansas as early as 2014. Metabolic-inhibitor and molecular assays indicated NTSR in these populations, mainly driven by GSTs. To understand the mechanism of resistance, selected candidate genes were analyzed in leaves and roots of survivors (with 1 × S-metolachlor). Expression analysis of the candidate genes showed that the primary site of S-metolachlor detoxification in A. palmeri is in the roots. Two GST genes, ApGSTU19 and ApGSTF8 were constitutively highly expressed in roots of all plants across all resistant populations tested. The expression of both GSTs increased further in survivors after treatment with S-metolachlor. The induction level of ApGSTF2 and ApGSTF2like by S-metolachlor differed among resistant populations. Overall, higher expression of ApGSTU19, ApGSTF8, ApGSTF2, and ApGSTF2like, which would lead to higher GST activity in roots, was strongly associated with the resistant phenotype. Phylogenetic relationship and analysis of substrate binding site of candidate genes suggested functional similarities with known metolachlor-detoxifying GSTs, effecting metabolic resistance to S-metolachlor in A. palmeri. Resistance is achieved by elevated baseline expression of these genes and further induction by S-metolachlor in resistant plants.

Glutathione S-transferase activity and genetic polymorphisms associated with exposure to organochloride pesticides in Todos Santos, BCS, Mexico: a preliminary study

The objective of this study was to identify and evaluate the impact of exposure to mixtures of organochloride pesticides (OCPs) in agricultural workers by detecting their effects on the activity of the enzyme glutathione S-transferase (GST) and the presence of polymorphisms of the GSTT1 and GSTM1 genes. The presence of OCPs was identified and quantified by gas chromatography, while spectrophotometry was used to measure enzymatic GST activity. The frequencies of the GSTM1 genotypes were analyzed by multiplex PCR. A total of 18 metabolites of OCPs were identified in the workers' blood, most of which are either prohibited (DDT and its metabolites p, p'DDD and p, p'DDE, dieldrin, endrin, aldrin) and/or restricted (δ hexachlorocyclohexane, cis chlordane, methoxychlor, and endosulfan). The results obtained indicate lower levels of GST activity at higher OCPs concentrations detected in blood from exposed workers, together with an increase in OCP levels in individuals who presented the GSTT1*0 and GSTM1*0 genotypes. These conditions place the detoxification process in agricultural workers with null polymorphisms in the GST genes and high concentrations of OCPs in the blood (especially DDT and its metabolites, DDD and DDE) at risk, and increase their susceptibility to develop serious diseases.

Benzopyrene induces oxidative stress and increases expression and activities of antioxidant enzymes, and CYP450 and GST metabolizing enzymes in Ulva lactuca (Chlorophyta)

Benzopyrene is rapidly incorporated and metabolized, and induces oxidative stress and activation of antioxidant enzymes, and CYP450 and GST metabolizing enzymes in Ulva lactuca. To analyze absorption and metabolism of benzo[a]pyrene (BaP) in Ulva lactuca, the alga was cultivated with 5 µM of BaP for 72 h. In the culture medium, BaP level rapidly decreased reaching a minimal level at 12 h and, in the alga, BaP level increased until 6 h, remained stable until 24 h, and decreased until 72 h indicating that BaP is being metabolized in U. lactuca. In addition, BaP induced an initial increase in hydrogen peroxide decreasing until 24 h, superoxide anions level that remained high until 72 h, and lipoperoxides that initially increased and decreased until 72 h, showing that BaP induced oxidative stress. Activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (AP), glutathione reductase (GR) and glutathione peroxidase (GP) were increased, whereas dehydroascorbate reductase (DHAR) activity was unchanged. The level of transcripts encoding these antioxidant enzymes was increased, but transcripts encoding DHAR remained unchanged. Interestingly, the activity of glutathione-S-transferase (GST) was also increased, and inhibitors of cytochrome P450 (CYP450) and GST activities enhanced the level of BaP in algal tissue, suggesting that these enzymes participate in BaP metabolism.

Biotransformation in the fish Prochilodus lineatus: An organ-specific approach to cyp1a gene expression and biochemical activity

The biotransformation ability of the organism is the result of organ-specific responses. This paper presents a molecular and biochemical approach to elucidate the biotransformation mechanisms in different organs of Prochilodus lineatus induced at 6, 24, and 96 h after a benzo[a]pyrene (B[a]P) injection. The induction in cyp1a transcription showed an organ-specific intensity at every tested time time. The EROD (ethoxyresorufin-O-deethylase) activity increased rapidly (6 h) in the liver and the kidney; the gills and the brain showed an increase at 24 h; and the gills demonstrated the highest activity among all the organs tested. There was no increase in glutathione S-transferase (GST) activity or lipoperoxidation. The decreased hepatic glutathione content (GSH) may be due to its role as an antioxidant. B[a]P was detected in the bile, confirming the xenobiotic efflux from the metabolizing organs. The gills, liver, brain, and kidney of P. lineatus presented an integrated mechanism to deal with the xenobiotic biotransformation.

Melatonin ameliorates degenerative alterations caused by age in the rat prostate and mitigates high-fat diet damages

Imbalance of sexual steroids milieu and oxidative stress are often observed during aging and correlated to prostate disorders. Likewise, high-fat intake has been related to prostate damage and tumor development. Melatonin (MLT) is an antioxidant whose secretion decreases in elderly and is also suggested to protect the gland. This study evaluated the impact of a long-term high-fat diet during aging on prostate morphology and antioxidant system of rats and tested the effects of MLT supplementation under these conditions. Male rats were assigned into four groups: control, treated with MLT, high-fat diet and high-fat diet treated with MLT. The high-fat diet was provided from the 24th week of age, MLT from the 48th (100 μg/kg/day) and rats were euthanized at the 62nd week. The high-fat diet increased body weight, retroperitoneal fatness, glycaemia, and circulating estrogen levels. It aggravated the aging effects, leading to epithelial atrophy (∼32% reduction of epithelial height) and collagen fibers increase (83%). MLT alone did not alter biometric and physiological parameters, except for the prostate weight decrease, whereas it alleviated biometric as well as ameliorated acinar atrophy induced by high-lipid intake. Systemic oxidative stress increased, and prostatic glutathione peroxidase activity decreased fivefold with the high-fat diet despite the indole. Regardless of the diet, MLT triggered epithelial desquamation, reduced androgen receptor-positive cells, increased smooth muscle layer thickness (12%), decreased at least 50% corpora amylacea formation, and stimulated prostatic gluthatione-S-transferase activity. In conclusion, MLT partially recovered prostate damage induced by aging and the long-term high-fat diet and ameliorated degenerative prostate alterations.

Does Gender Matter in Explaining Delinquency and Suicidal Thoughts? An Examination of General Strain Theory in South Korean Youths

This study attempts to explore the potential extension of general strain theory (GST) by applying the hypotheses proposed by Broidy and Agnew to a sample of South Korean youths. Specifically, this study examines whether particular forms of strain and stressors have differential effects across genders on various deviant outcomes, delinquency, and suicidal thoughts. Multiple regression analyses using longitudinal data of 3,125 South Korean youths revealed mixed support for the GST proposition. Females experienced a higher level of both anger and depression than males. However, the experience of negative emotions is partly gendered in general. This study also found that different negative emotions and strain/stress factors are important and demonstrate gendered pathways in the case of delinquency. However, it also revealed that similar types of strains and stressors and negative emotions were significant and positive for suicidal thoughts for both males and females. Furthermore, a model examining the impacts of conditioning variables on suicidal thoughts highlighted that depression is particularly important in females. These findings indicate that various types of deviant outcomes and strain-stressors provide a fuller understanding of both similarities and differences by gender.

Molecular basis of inhibition of Schistosoma japonicum glutathione transferase by ellagic acid: Insights into biophysical and structural studies

Schistosoma japonicum glutathione transferase (Sj26GST), an enzyme central to detoxification of electrophilic compounds in the parasite, is upregulated in response to drug treatment. Therefore, Sj26GST may serve as a potential therapeutic target for the treatment of schistosomiasis. Herewith, we describe the structural basis of inhibition of Sj26GST by ellagic acid (EA). Using 1-chloro-2,4-dinitrobenzene and reduced glutathione (GSH) as Sj26GST substrates, EA was shown to inhibit Sj26GST activity by 66 % with an IC₅₀ of 2.4 μM. Fluorescence spectroscopy showed that EA altered the polarity of the environment of intrinsic tryptophan and that EA decreased (in a dose-dependent manner) the interaction between Sj26GST and 8-Anilino-1-naphthalenesulfonate (ANS), which is a known GST H-site ligand. Thermodynamic studies indicated that the interaction between Sj26GST and EA is spontaneous (ΔG = -29.88 ± 0.07 kJ/mol), enthalpically-driven (ΔH = -9.48 ± 0.42 kJ/mol) with a favourable entropic change (ΔS = 20.40 ± 0.08 kJ/mol/K), and with a stoichiometry of four EA molecules bound per Sj26GST dimer. The 1.53 Å-resolution Sj26GST crystal structure (P 21 21 21 space group) complexed with GSH and EA shows that EA binds primarily at the dimer interface, stabilised largely by Van der Waal forces and H-bonding. Besides, EA bound near the H-site and less than 3.5 Å from the ε-NH₂ of the γ-glutamyl moiety of GSH, in each subunit.

Characterisation of a Teladorsagia circumcincta glutathione transferase

A 615 bp full length cDNA encoding a Teladorsagia circumcincta glutathione transferase (TcGST) was cloned, expressed in Escherichia coli and the recombinant protein purified and its kinetic properties determined. The predicted protein consisted of 205 amino acids and was present as a single band of about 24 kDa on SDS-PAGE. Multiple alignments of the protein sequence of TcGST with homologues from other helminths showed that the highest identity of 53-68% with haem-binding nematode proteins designated as members of the nu class of GSTs. Substrate binding sites and conserved regions were identified and were generally conserved. The predicted 3-dimensional structures of TcGST and HcGST revealed highly open binding cavities typical of this class of GST, considered to allow greater accessibility to diverse ligands compared with other classes of GST. At 25 °C, the optimum pH for TcGST activity was pH 7, the V_max was 1535 ± 33 nmoles.min^-1. mg^-1 protein and the apparent K_m for the substrate 1-chloro-2,4-dinitrobenzene (CDNB) was 0.22 ± 0.01 mM (mean ± SD, n = 2). Antibodies in both serum and saliva from field-immune, but not nematode-naïve, sheep, recognised recombinant TcGST in enzyme-linked immunosorbent assays. The recognition of the recombinant protein by antibodies generated by exposure of sheep to the native enzyme indicates similar antigenicity of the two proteins. These findings could aid in the design of novel drugs and vaccine antigens for economically important parasites of livestock.

Expression of xenobiotic metabolising enzymes in lungs of horses with or without histological evidence of lower airway inflammation

Mild, moderate and severe equine asthma is a problem for equine welfare. The aetiology of the disease is not known in detail but is likely multi‐factorial. One important factor may be inhaled dust which carries harmful substances which may be bioactivated and thus can lead to local inflammation in the airways. The aim of this study was to investigate gene expression and protein localisation of cytochrome P450 (CYP) enzymes, superoxide dismutase and glutathione‐S‐transferases (GST) involved in bioactivation and detoxification of harmful substances in lungs of horses with or without histological evidence of lower airway inflammation. Significantly lower gene expression of CYP2A13 and GSTM1 was observed in lungs from horses with histological evidence of lower airway inflammation compared with horses without. A higher expression, although not significant, was found for CYP1A1 in horses with histological evidence of lower airway inflammation. There were no differences in gene expression of GSTP1 and SOD3. The proteins were localised in the respiratory epithelium which is of relevance as a defence to local exposure of inhaled harmful substances. In conclusion, our study reports differential gene expression of enzymes involved in bioactivation and detoxification of foreign substances in the lungs of horses with histological evidence of lower airway inflammation compared with horses without.

Glutathione-S-transferase (GST) catalyzes the degradation of Chlorimuron-ethyl by Klebsiella jilinsis 2N3

Microbial degradation is one of the most efficient and reliable ways to remove the residues of Chlorimuron-ethyl in the environments such as soil and water. In this study, a glutathione-s-transferase (GST) gene Kj-gst was cloned from the Chlorimuron-ethyl degrading bacterial strain Klebsiella jilinsis 2N3. Results showed that Kj-gst played a key role in the degradation of Chlorimuron-ethyl by strain 2N3. The mutant with gene Kj-gst knocked out showed reduced relative activity up to 70% compared with the wild type in 8 h in culture. After the knockout gene was complemented, the degradation ability of the complement mutant was essentially comparable to that of the wild type. The protein Kj-GST (50 μg) obtained from the gene Kj-gst expressed and purified in E. coli strain BL21(DE3) was capable of degrading Chlorimuron-ethyl with an initial concentration of 50 mg/mL by 42.91% under the optimal conditions (15 °C and pH = 7). Point mutation experiments on a glycine located at position 101 (Glu101) confirmed that the H site of glutathione (GSH) is the key component in Kj-GST for degrading Chlorimuron-ethyl. We conclude that Kj-GST is demonstrated for the first time to degrade Chlorimuron-ethyl with its main functional site identified at the H site of GSH, shedding insight to revealing the molecular mechanisms of degrading Chlorimuron-ethyl by Klebsiella jilinsis 2N3.

Molecular characterization of an anthocyanin-related glutathione S-transferase gene in Japanese gentian with the CRISPR/Cas9 system

BACKGROUND

The blue pigmentation of Japanese gentian flowers is due to a polyacylated anthocyanin, gentiodelphin, and all associated biosynthesis genes and several regulatory genes have been cloned and characterized. However, the final step involving the accumulation of anthocyanins in petal vacuoles remains unclear. We cloned and analyzed the glutathione S-transferases (GSTs) in Japanese gentian that are known to be involved in anthocyanin transport in other plant species.

RESULTS

We cloned GST1, which is expressed in gentian flower petals. Additionally, this gene belongs to the Phi-type GST clade related to anthocyanin biosynthesis. We used the CRISPR/Cas9-mediated genome editing system to generate loss-of-function GST1 alleles. The edited alleles were confirmed by Sanger and next-generation sequencing analyses. The GST1 genome-edited lines exhibited two types of mutant flower phenotypes, severe (almost white) and mild (pale blue). The phenotypes were associated with decreased anthocyanin accumulation in flower petals. In the GST1 genome-edited lines, sugar-induced stress conditions inhibited the accumulation of anthocyanins in stems and leaves, suggestvhing that GST1 is necessary for stress-related anthocyanin accumulation in organs other than flowers. These observations clearly demonstrate that GST1 is the gene responsible for anthocyanin transport in Japanese gentian, and is necessary for the accumulation of gentiodelphin in flowers.

CONCLUSIONS

In this study, an anthocyanin-related GST gene in Japanese gentian was functionally characterized. Unlike other biosynthesis genes, the functions of GST genes are difficult to examine in in vitro studies. Thus, the genome-editing strategy described herein may be useful for in vivo investigations of the roles of transport-related genes in gentian plants.

Small Extracellular Vesicles Have GST Activity and Ameliorate Senescence-Related Tissue Damage

Aging is a process of cellular and tissue dysfunction characterized by different hallmarks, including cellular senescence. However, there is proof that certain features of aging and senescence can be ameliorated. Here, we provide evidence that small extracellular vesicles (sEVs) isolated from primary fibroblasts of young human donors ameliorate certain biomarkers of senescence in cells derived from old and Hutchinson-Gilford progeria syndrome donors. Importantly, sEVs from young cells ameliorate senescence in a variety of tissues in old mice. Mechanistically, we identified sEVs to have intrinsic glutathione-S-transferase activity partially due to the high levels of expression of the glutathione-related protein (GSTM2). Transfection of recombinant GSTM2 into sEVs derived from old fibroblasts restores their antioxidant capacity. sEVs increase the levels of reduced glutathione and decrease oxidative stress and lipid peroxidation both in vivo and in vitro. Altogether, our data provide an indication of the potential of sEVs as regenerative therapy in aging.

Genome-wide identification and comparative analysis of GST gene family in apple (Malus domestica) and their expressions under ALA treatment

Anthocyanins, a subclass of flavonoids, are synthesized at the cytoplasmic surface of the endoplasmic reticulum (ER), which then accumulate in vacuoles. Plant glutathione S-transferase (GST) genes are involved in anthocyanin transportation. Here, a total of 52, 42, 50, and 29 GST genes were identified from apple, pear, peach, and strawberry, respectively, through a comprehensive genome-wide survey. Based on phylogenetic analyses, the GST proteins of the four crops could be divided into the classes Phi, Tau, DHAR, TCHQD, and Lambda. The structure and chromosomal distribution of apple GST genes were further analyzed. The GST gene family expansion in apple likely occurred through tandem duplications, and purifying selection played a pivotal role in the evolution of GST genes. Synteny analysis showed strong microsynteny between apple and Arabidopsis/strawberry, but no microsynteny was detected between apple/strawberry/Arabidopsis and rice. Aminolevulinic acid (ALA), a key precursor of tetrapyrrole compounds, can significantly improve anthocyanin accumulation in fruits, Using RNA-seq and qRT-PCR analysis, we found that ALA treatment led to the differential expression of GST genes in apples. MdGSTF12 was strongly induced by ALA, suggesting that MdGSTF12 may play a role in ALA-induced anthocyanin accumulation. These results provide a detailed overview of GST genes in four Rosaceae species and indicate that GSTs are involved in ALA-induced anthocyanin accumulation.

Epigenetic study of global gene methylation in PON1, XRCC1 and GSTs different genotypes in rural and urban pesticide exposed workers

Background Epigenetic represents a study of occurred heritable gene expression changes without changing in the DNA sequence. It includes DNA methylation and miRNA expression that attract increasing attention as potential links between the genetic and environmental determinants of health and disease. Pesticide exposure is associated with adverse health effects and DNA methylation due to oxidative stress induced following its exposure. This study aimed to define the association of genetic polymorphisms of XRCC1, PON1, GSTP1 and GST genes with global genes DNA methylation in urban and rural occupationally pesticides exposed workers. Methods This study included 100 pesticides exposed workers; 50 rural sprayers (RE) and 50 urban researchers (UE). Controls included equal numbers. DNA methylation of global genes was evaluated by pyrosequencing assay. XRCC1, PON1 and GSTP1 genotyping were assessed by PCR-RFLP, and GST M1 and T1 were performed by PCR. Results The results of this study revealed that most genotypes in XRCC1, PON1, GSTP1 and GST genes were associated with LINE-1 hypomethylation among UE group. However, heterozygote genotypes (Gln-Arg and Ile-Val) in XRCC1 and GSTP1 genes, respectively, were associated with LINE-1 hypermethylation among UE compared with other corresponding genotypes. Only GSTT1 polymorphism recorded a significant change in percent methylation of Alu elements among urban and rural groups. Conclusion Urbanization could play an additional risk for epigenetic changes associated with pesticide exposure, and that could be attributed to the quality of life including their dietary habits, working and living in closed areas, and their exposure to extra pollutions emitted from urbanization sources.

The Effect of Rosmarinus officinalis Essential Oil Fumigation on Biochemical, Behavioral, and Physiological Parameters of Callosobruchus maculatus

This study explores the influence of rosemary, Rosmarinus officinalis (L.) essential oil (EO) on the biochemical (acetylcholinesterase, catalase, and glutathione S-transferase), physiological (oxygen consumption), and behavioral (open field test, repellency) parameters of an important stored product insect: cowpea weevil, Callosobruchus maculatus (F.). R. officinalis EO exhibited effective insecticidal action against C. maculatus even at relatively low concentrations. LC50 = 15.69 μL/L air, and was highly repellent at concentrations equal to or above LC25. Statistically significant inhibition in locomotor activity occurred only after the acute exposure to the EO at LC12.5 and LC25. The oxygen consumption test showed metabolism increase only at LC50. An increase in activity was observed in the case of all three enzymes examined. The presented data provides a potentially valuable resource in designing more environmentally friendly and safer insecticide agents.

Cochlear detoxification: Role of alpha class glutathione transferases in protection against oxidative lipid damage, ototoxicity, and cochlear aging

Age-related hearing loss (AHL) is the most common form of hearing impairment. AHL is thought to be a multifactorial condition resulting from the interaction of numerous causes including aging, genetics, exposure to noise, and exposure to endogenous and exogenous toxins. Cells possess many detoxification enzymes capable of removing thousands of cytotoxic xenobiotics and endogenous toxins such as 4-hydroxynonenal (4-HNE), one of the most abundant cytotoxic end products of lipid peroxidation. The cellular detoxification system involves three phases of enzymatic detoxification. Of these, the glutathione transferase (GST) detoxification system converts a toxic compound into a less toxic form by conjugating the toxic compound to reduced glutathione by GST enzymes. In this review, we describe the current understanding of the cochlear detoxification system and examine the growing link between GST detoxification, oxidative lipid damage, ototoxicity, and cochlear aging with a particular focus on the alpha-class GSTs (GSTAs). We also describe how exposure to ototoxic drugs, exposure to noise, or aging results in increased 4-HNE levels, how 4-HNE damages various cell components under stress conditions, and how GSTAs detoxify 4-HNE in the auditory system.

Protective effects of extracts of lichen Dirinaria consimilis (Stirton) D.D. Awasthi in bifenthrin- and diazinon-induced oxidative stress in rat erythrocytes in vitro

The intoxication of insecticides such as bifenthrin and diazinon has been reported to generate free radicals, and thereby alter the antioxidant defense system in erythrocytes. The present study is aimed to investigate the protective effects of acetone (DA) and methanolic (DM) extracts of lichen Dirinaria consimilis against bifenthrin and diazinon toxicity in rats' erythrocytes in vitro. Rats' erythrocytes were exposed to bifenthrin and diazinon, individually and also in combination with DA or DM at 1 ppm for 3 h at 37 ˚C. By using spectrophotometric methods, all the samples were estimated for changes in hemoglobin (Hb) concentration, malondialdehyde (MDA) levels, and enzyme [Superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferases (GST)] activities. The outcomes showed that both the insecticides were highly toxic to rats' erythrocytes. Among all groups, both the insecticides and DA exposed groups showed very low levels of MDA content, and GST activity in rats' erythrocytes, when compared to the control. Besides, DA groups pretreated with both insecticides showed significant improvement of total Hb concentration, SOD, and CAT activities, with respect to the control. Hence, the present results indicate that the extracts of D. consimilis act as an antioxidant agent that reduces oxidative stress burden in insecticides toxicity.

Divergent molecular evolution in glutathione S-transferase conferring malathion resistance in the oriental fruit fly, Bactrocera dorsalis (Hendel)

Insect glutathione S-transferases (GSTs) are important in insecticide detoxification and Insect-specific GSTs, Epsilon and Delta, have largely expanded in insects. In this study, we functionally expressed and characterized an epsilon class GST gene (BdGSTe8), predominant in the adult Malpighian tubules of Bactrocera dorsalis. This gene may be associated with malathion resistance based on transcriptional studies of resistant and susceptible strains. RNA interference-mediated knockdown of this gene significantly recovered malathion susceptibility in the adults of a malathion-resistant strain, and overexpression of BdGSTe8 enhanced resistance in transgenic Drosophila. Analysis of BdGSTe8 polymorphism showed that several point mutations may be associated with metabolic resistance to malathion. A cytotoxicity assay in Escherichia coli indicated that both of the recombinant BdGSTe8 proteins may play a functional role in protecting cells from toxicity. The allele of BdGSTe8-B conferred higher levels of malathion detoxification capability. Liquid chromatography and ultra-performance liquid chromatography-tandem mass spectrometry analysis showed that the BdGSTe8-A allele did not metabolize malathion directly. However, the BdGSTe8-B allele was involved in the direct metabolism of malathion, which was caused by a mutation in V128A. Further analysis of the sequence suggests that BdGSTe8 evolved rapidly. It maybe play the role of a backup gene and could become a new gene in the future in order to retain the ability of detoxification of malathion, which was driven by positive selection. These results suggest that divergent molecular evolution in BdGSTe8 has played a role in metabolic resistance to malathion in B. dorsalis.