OBJECTIVES: This study aims to investigate the impact of glutathione S-transferase (GST) on the environmental adaptability of Streptococcus mutans (S. mutans). METHODS: A GST knockout strain ΔgsT was constructed. Transcriptomic sequencing was performed to analyze the gene expression differences between the wild-type S. mutans UA159 and its GST knockout strain ΔgsT. Comprehensive functional assessments, including acid tolerance assays, hydrogen peroxide challenge assays, nutrient limitation growth assays, and fluorescence in situ hybridization, were conducted to evaluate the acid tolerance, antioxidant stress resistance, growth kinetics, and interspecies competitive ability of ΔgsT within plaque biofilms. RESULTS: Compared with the wild-type S. mutans, 198 genes in ΔgsT were significantly differentially expressed and enriched in pathways related to metabolism, stress response, and energy homeostasis. The survival rate of ΔgsT in acid tolerance assays was markedly reduced (P<0.01). After 15 min of hydrogen peroxide challenge, the survival rate of ΔgsT decreased to 38.12% (wild type, 71.75%). Under nutrient-limiting conditions, ΔgsT exhibited a significantly lower final OD₆₀₀ value than the wild-type strain (P<0.05). In the biofilm competition assays, the proportion of S. mutans ΔgsT in the mixed biofilm (8.50%) was significantly lower than that of the wild type (16.89%) (P<0.05). CONCLUSIONS GST enhances the acid resistance, oxidative stress tolerance, and nutrient adaptation of S. mutans by regulating metabolism-related and stress response-related genes.
Streptococcus mutans/enzymology* ; Biofilms ; Glutathione Transferase/physiology* ; Adaptation, Physiological ; Hydrogen Peroxide/pharmacology* ; Gene Expression Regulation, Bacterial ; Oxidative Stress ; Metabolic Reprogramming

Helicobacter pylori infection is related to the development of gastric diseases. Our previous studies showed that high thioredoxin-1 (Trx1) expression in H. pylori can promote gastric carcinogenesis. To explore the underlying molecular mechanisms, we performed an isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomic analysis of stomach tissues from Mongolian gerbil infected with H. pylori expressing high and low Trx1. Differences in the profiles of the expressed proteins were analyzed by bioinformatics and verified using Western blot analysis. We found three candidate proteins, 14-3-3α/β, glutathione-S-transferase (GST), and heat shock protein 70 (HSP70), in high Trx1 tissues compared with low Trx1 tissues and concluded that cellular stress and redox activity-related proteins were involved in the pathogenesis of gastric cancer associated with H. pylori Trx1.
14-3-3 Proteins/physiology* ; Animals ; Computational Biology ; Gerbillinae ; Glutathione Transferase/physiology* ; HSP70 Heat-Shock Proteins/physiology* ; Helicobacter Infections/complications* ; Helicobacter pylori ; Oxidation-Reduction ; Stomach Neoplasms/etiology* ; Stress, Physiological ; Thioredoxins/physiology*

OBJECTIVETo investigate the characteristics of phase II metabolic enzymes in mouse embryonic stem (ES) cell-derived liver tissue.

METHODSMature hepatocytes were differentiated from embryonic stem cells in cultured mouse embryoid bodies (EB) at d18. Western blot was used to detect the expression of uridine 5'-diphosphate glucronosyl transferase (UGT1a1,UGT1a6) and microsomal glutathione S-transferases 1(mGST1) during the differentiation course.The derived liver tissue was incubated with UDPGA and 7-HFC,the formation of 7-HFC glucuronide was detected by HPLC to examine the total activities of UGT1a1 and UGT1a6. Furthermore, the microsomes were incubated with CDNB and GSH,and the mGST1 activity was measured by spectrometry.

RESULTSAn increase tendency of UGT1a1 expression was noticed during the differentiation course. UGT1a6 and mGST1 were not detected in the earlier stage until d18 of differentiation. The metabolic activity of mGST1 in the derived hepatocytes was 7.65 nmol/min/mg on d18.

CONCLUSIONThe ES cell-derived liver tissue possesses partial metabolic function of phase II enzymes on d18 of differentiation,which might be used as a model for in vitro research on hepatic pathophysiology and phase II drug metabolism.

Animals ; Cell Differentiation ; Embryoid Bodies ; cytology ; Embryonic Stem Cells ; cytology ; Glucuronosyltransferase ; physiology ; Glutathione Transferase ; physiology ; Hepatocytes ; cytology ; enzymology ; Mice

Oxidative stress may reduce cardiovascular function. Glutathione Stransferases(GSTs) play an important role in cell defending against oxidative stress. Glutathione S-transferase P1 (GSTP1) gene is one of the most intensively investigated glutathione S-transferase genes in epidemiologic studies. The GSTP1 gene displays a polymorphism at codon 105 (Ile105 Val), which results in an enzyme with altered substrate affinity. To date, there have been few studies evaluating whether Ilel05Val polymorphism of GSTP1 gene has an effect on cardiovascular function in the broad masses of people. In this study, we investigated the relationship between Ile105 Val polymorphism of GSTP1 gene and heart rate and blood pressure in 197 unrelated adult males of Han nationality. It was found that there were two types of the GSTP1 genotypes, Ile105/Ile105 and Ile105/Val105, but genotype Val105/Val105 was not found, and the frequencies of IleIes/Ileos and Ile105/Val105 genotypes were 78% and 22% respectively. Comparison with individuals with lie105/Val105 genotype showed that those with Ile105/Ile105 genotype had higher rest heart rate and maximal heart rate mean values. However, whether for rest heart rate and maximal heart rate or for heart rate reserve, no significant differences were found between the two genotype groups (P>0.05). Compared with individuals with Ile105/Val105 genotype, those with Iler105/Ile105 genotype had higher systolic blood pressure and pulse pressure mean values and lower diastolic blood pressure mean value. However, for systolic blood pressure, diastolic blood pressure and pulse pressure, no significant differences were found between the two genotype groups (P>0.05). The results suggested that Ile105 Val polymorphism of GSTP1 gene may not be associated with heart rate and blood pressure in the broad masses of people.
Adult ; Blood Pressure ; physiology ; Genotype ; Glutathione S-Transferase pi ; genetics ; Heart Rate ; physiology ; Humans ; Male ; Polymorphism, Genetic

AIMTo examine whether a relationship exists between glutathione S-transferase Mu-1 (GSTM1) gene polymorphism and the susceptibility of sperm and seminal plasma from patients with idiopathic infertility to oxidative stress.

METHODSFifty-two men with idiopathic infertility and 60 healthy fertile men were recruited to this study. GSTM1 gene polymorphism was determined by polymerase chain reaction (PCR) and both the infertile and control individuals were divided into GSTM1 null and GSTM1 positive groups according to their GSTM1 gene structure. We compared reactive oxygen species (ROS) generation, malondialdehyde (MDA), protein carbonyls and glutathione (GSH) concentrations, and glutathione S-transferase (GST) activity in seminal plasma and spermatozoa from infertile patients and controls with respect to GSTM1 genotype.

RESULTSSignificantly higher levels of oxidative stress and damage markers were found in idiopathic infertile men with the GSTM1 null genotype compared with those with the GSTM1 positive genotype. There was no significant difference in genotype distribution for the GSTM1 variant between the idiopathic infertile subjects and fertile subjects. Patients with the GSTM1 null genotype also had lower sperm concentrations than those with GSTM1 positive genotype.

CONCLUSIONOur results suggest that the susceptibility of sperm and seminal plasma to oxidative stress is significantly greater in idiopathic infertile men with the GSTM1 null genotype compared with those possessing the gene. Therefore, in patients with idiopathic infertility, GSTM1 polymorphism might be an important source of variation in susceptibility of spermatozoa to oxidative damage.

DNA Primers ; Genotype ; Glutathione ; metabolism ; Glutathione Transferase ; deficiency ; Humans ; Infertility, Male ; enzymology ; genetics ; Male ; Oxidative Stress ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Reactive Oxygen Species ; metabolism ; Reference Values ; Semen ; physiology ; Spermatozoa ; pathology

OBJECTIVETo investigate the blockness effects of purified polyclonal anti-porin I antibody on N. gonorrhoeae adherence to genitourinary tract epithelia of BALB/c mouse.

METHODSPolyclonal anti GST-PI antibody was generated by immunizing rabbit with GST-PI fusion protein which was constructed and expressed by ourselves. The purified immunoglobulin G was obtained by ammonium sulphate deposition and DEAE cellulose chromatography. Mice model of gonorrhea was established. In order to evaluate the effects of PI-IgG on gonococcus adhesion to vagina mucus, the macroscopic and pathological assessing as well as gonococcus culture was employed after gonococcus challenge on PI-IgG immunized mice.

RESULTNo pus and pathological inflammation were observed on mice vagina mucus treated with 1 mg/ml PI-IgG 3 hours before gonococcus challenge. Gonococcus could not be detected in the smears and washing solutions from vagina. Pathological inflammation was found in mice treated with anti PI-IgG, in which the concentrations were lower than 1 mg/ml or the treated time was longer than 3 hours prior to gonococcus challenge.

CONCLUSIONThe purified anti PI-IgG can effectively inhibit the adherence and infection of gonococci to genitourinary tract epithelia of BALB/c mice. In addition, the blocking duration of anti PI-IgG is associated with antibody concentration.

Animals ; Antibodies, Monoclonal ; pharmacology ; Bacterial Adhesion ; drug effects ; Epithelium ; drug effects ; microbiology ; Female ; Glutathione Transferase ; biosynthesis ; genetics ; Gonorrhea ; microbiology ; prevention & control ; Mice ; Mice, Inbred BALB C ; Neisseria gonorrhoeae ; drug effects ; physiology ; Porins ; biosynthesis ; genetics ; immunology ; Rabbits ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Urogenital System ; drug effects ; microbiology

Phosphoinositide-specific phospholipase C-gamma1 (PLC-gamma1) has two pleckstrin homology (PH) domains: an amino-terminal domain (PH1) and a split PH domain (PH2). Here, we show that overlay assay of bovine brain tubulin pool with glutathione-S-transferase (GST)-PLC-gamma1 PH domain fusion proteins, followed by matrix-assisted laser-desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), identified 68-kDa neurofilament light chain (NF-L) as a binding protein of amino-terminal PH domain of PLC-gamma1. NF-L is known as a component of neuronal intermediate filaments, which are responsible for supporting the structure of myelinated axons in neuron. PLC-gamma1 and NF-L colocalized in the neurite in PC12 cells upon nerve growth factor stimulation. In vitro binding assay and immunoprecipitation analysis also showed a specific interaction of both proteins in differentiated PC12 cells. The phosphatidylinositol 4, 5-bisphosphate [PI(4,5)P2] hydrolyzing activity of PLC-gamma1 was slightly decreased in the presence of purified NF-L in vitro, suggesting that NF-L inhibits PLC-gamma1. Our results suggest that PLC-gamma1-associated NF-L sequesters the phospholipid from the PH domain of PLC-gamma1.
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Rats ; Protein Interaction Mapping ; Protein Biosynthesis/drug effects ; Protein Binding/drug effects ; Phosphoproteins/chemistry/*metabolism ; Phospholipase C gamma/antagonists & inhibitors/chemistry/*metabolism ; Phosphatidylinositol 4,5-Diphosphate/metabolism ; Peptides/chemistry/metabolism ; PC12 Cells ; Neurofilament Proteins/chemistry/*metabolism ; Nerve Growth Factor/pharmacology ; Molecular Weight ; Molecular Sequence Data ; Microtubules/metabolism ; Microscopy, Fluorescence ; Isoenzymes/metabolism/pharmacology/physiology ; Glutathione Transferase/metabolism ; Blotting, Far-Western ; Blood Proteins/chemistry/*metabolism ; Binding Sites ; Animals ; Amino Acid Sequence

BpHi006A cDNA is 1943 bp in length, and contains one putative open reading frame that is 795 bp long. The expression of BpHi006A was induced by BPH feeding. BpHi006A protein contains a N-terminal domain and a C-terminal domain of glutathione S-transferase, and therefore, it belongs to the superfamily of glutathione S-transferase. BpHi006A protein exhibited 61% amino acid sequence identity to tetrachloro-p-hydroquinone reductive dehalogenase-related protein of Arabidopsis thaliana. Sequence analysis of these two proteins indicates that they belong to a new group of plant GSTs.
Amino Acid Sequence ; Animals ; Cloning, Molecular ; Genes, Plant ; Glutathione Transferase ; genetics ; Hemiptera ; physiology ; Molecular Sequence Data ; Open Reading Frames ; Oryza ; enzymology ; genetics ; Plant Proteins ; genetics

AIMTo evaluate the effect of oxidative stress on the spermatogenesis and lactate dehydrogenase-X (LDH-X) activity in mouse testis.

METHODSFor creating different levels of oxidative stress in mice, three selenium (Se) level diets were fed in separate groups for 8 weeks. Group 1 animals were fed yeast-based Se-deficient (0.02 ppm) diet. Group 2 and Group 3 animals were fed with the same diet supplemented with 0.2 ppm and 1 ppm Se as sodium selenite, respectively. After 8 weeks, biochemical and histopathological observations of the testis were carried out. LDH-X levels in the testis were analyzed by western immunoblot and ELISA.

RESULTSA significant decrease in testis Se level was observed in Group 1 animals, whereas it was enhanced in Group 3 as compared to Group 2. The glutathione peroxidase (GSH-Px) activity was significantly reduced in both the liver and testis in Group 1, but not in Group 2 and 3. A significant increase in the testis glutathione-S-transferase (GST) activity was observed in Group 1, whereas no significant change was seen in Groups 2 and 3. Histological analysis of testis revealed a normal structure in Group 2. A significant decrease in the germ cell population in Group 1 was observed as compared to Group 2 with the spermatids and mature sperm affected the most. Decrease in the lumen size was also observed. In the Se-excess group (Group 3), displacement of germ cell population was observed. Further, a decrease in the LDH-X level in testis was observed in Group 1.

CONCLUSIONExcessive oxidative stress in the Se deficient group, as indicated by changes in the GSH-Px/GST activity, affects the spermatogenic process with a reduction in mature sperm and in turn the LDH-X level.

Animals ; Diet ; Glutathione Transferase ; metabolism ; Isoenzymes ; drug effects ; metabolism ; L-Lactate Dehydrogenase ; drug effects ; metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Oxidative Stress ; drug effects ; physiology ; Selenium ; deficiency ; pharmacokinetics ; pharmacology ; Spermatogenesis ; physiology ; Testis ; drug effects ; enzymology ; pathology ; physiology

Glutathione S-transferase (28GST) with molecular mass of 28 kDa is an antioxidant enzyme abundant in Clonorchis sinensis. In adult C. sinensis, 28GST was localized in tegumental syncytium, cytons, parenchyma, and sperm tails examined by immunoelectron microscopy. C. sinensis 28GST was earlier found to neutralize bioreactive compounds and to be rich in eggs. Accordingly, it is suggested that 28GST plays important roles in phase II defense system and physiological roles in worm fecundity of C. sinensis.
Animals ; Clonorchis sinensis/*enzymology ; Glutathione Transferase/*metabolism/physiology ; Immunohistochemistry ; Microscopy, Immunoelectron ; Molecular Weight ; Support, Non-U.S. Gov't