Carboxylesterase and Glutathione-S-Transferase （GST＇s） Induced Resistance to Bacillus thuringiensis Toxin CrylAb in Rice Leaf Folder, Cnaphalocrocis medinalis （Guenee） Populations

The rice leaf folder （RLF）, Cnaphalocrocis medinalis （Guenee） （lnsecta： Lepidoptera： Pyralidae）, is an important pest, widely distributed in many rice growing areas of Asia. The over-use of broad-spectrum chemical insecticides has been cited as a major cause of outbreaks of C. medinalis as excessive spraying of insecticide disrupts natural biological control insecticides still remain the major control tactics against leaf folder. Carbofuran and fenthion, bendiocarb, acephate, carbosulfan, quinolphos, monocrotophos, phosphamidon and fenvalerate are the common ones used against rice leaf folder. Genetically, modified rice lines expressing B. thuringiensis insecticidal crystal proteins produced are highly tolerant to leidopteran pests. Though economic and environmental benefits of GM crops is well established, the matter of concern is the possibility of target insect pest developing resistance to this B. thuringiensis insecticidal toxins, evident from many laboratory and field experiments against many insect pests. The involvement of GSH S-transferase, carboxylesterase, and microsomal monooxygenase in insecticide resistance has been reported in insecticide-resistant strains of many insect species. Hence, the present study was taken up to monitor for cross resistance between B. thuringiensis cry toxins and synthetic insecticides in larvae of leaf folder as it is mediated by carboxylesterase titre and other enzymes by bioassay for two selected rice leaf folder field populations at the Entomology division of Directorate of Rice Research which showed 2-fold resistance ratio. Qualitative and quantitative changes of carboxylesterase （CarE） and glutathione-s-transferase （GST＇s） were worked out with midguts extracts of the two C. medinalis populations in the presence of a-napthyl acetate and chlorodi-nitro benzene substrates.

Inhibitory effect of active ingredients of Tripterygium wilfordii Hook.F.on human carboxylesterases

OBJECTIVE The inhibitory effect of active ingredients of Tripterygium wilfordii Hook.F.(TWHF)(celastrol,triptolide,triptonide,wilforlide A,wilforgine and wilforine)on human carboxylester⁃ase 1(CES1)and CES2 was detected to investigate the herb-drug interactions(HDIs)of TWHF.METHODS Human liver microsomes catalysed hydrolysis of 2-(2-benzoyl-3-methoxyphenyl)benzothi⁃azole(BMBT)and fluorescein diacetate(FD)were used as the probe reaction to phenotype the activity of CES1 and CES2,respectively.The residual activities of CES1 and CES2 were detected by ultrahigh performance liquid chromatography(UPLC)after intervention with celastrol,triptolide,triptonide,wilforlide A,wilforgine and wilforine(100μmol·L^(-1)).Kinetics analysis,involving half inhibitory concentra⁃tion(IC_(50)),inhibition type and kinetic parameter(Ki),and in vitro-in vivo extrapolation(IVIVE),was carried out to predict the HDIs between these compounds and CES-metabolizing drugs.Molecular docking was performed to analyze the ligand-enzyme interaction.RESULTS Out of the six main con⁃stituents of TWHF,only celastrol exhibited strong inhibition towards both CES1 and CES2,with the inhibitory rates of 97.45%(P<0.05)and 95.62%(P<0.05),respectively.The IC_(50)was 9.95 and 4.02 mol·L^(-1),respectively,and the types of inhibition were all non-competitive inhibition.Based on the kinetics analysis,the Ki values were calculated to be 5.10 and 10.55μmol·L^(-1)for the inhibition of celastrol on CES1 and CES2,respectively.IVIVE indicated that celastrol might disturb the metabolic hydrolysis of clinical drugs in vivo by inhibiting CES1.Molecular docking results showed that hydrogen bonds and hydrophobic contacts contributed to the interaction of celastrol and CESs.CONCLUSION The inhibitory effect of celastrol on CES1 and CES2 might cause HDIs with clinical drugs hydrolysed by CESs.

Effect of Transgenic Bt plus CpTI Cotton on Carboxylesterase and Acetylcholinesterase of Cotton Aphid Aphis gossypii

[Objective] The research aimed to assess the effect of transgenic Bt plus CpTI cotton variety SGK321 on carboxylesterase and acetylcholinesterase of cotton aphid Aphis gossypii and provide theoretical basis for studying the biosafety of transgenic cotton.[Method] Cotton aphids were fed with SGK321 and Shiyuan321（normal parental varieties） for over 40 generations.Enzyme activities were compared between cotton aphids feeding on SGK321 for 1,2,3,41,42 and 43 generations with those on Shiyuan321.[Result] The carboxylesterase activity of cotton aphids feeding on SGK321 for 1 generation was significantly higher than those feeding on Shiyuan321.Acetylcholinesterase activity of cotton aphids feeding on SGK321 for 1,2 and 3 generations were significantly higher than those feeding on Shiyuan321 in the same generation.But there was no significant difference of enzyme activity between cotton aphids feeding on SGK321 for a long term and those feeding on parental cotton.[Conclusion] The cotton aphid that feeding on transgenic Bt plus CpTI cotton SGK321 for a long time has adaptivity to SGK321 by regulating the detoxifying enzyme.

Characterization of Carboxylesterase Associated with Malathion Insensitivity in the Field Population of the Oriental Migratory Locust

Carboxylesterases （CarEs） from two field populations of the oriental migratory locust, Locusta migratoria manilensis （Meyen）, were examined to try to understand their contribution to malathion insensitivity. The CarEs activities in Wudi population （WD） were 1.75- and 1.50-fold significantly higher than those in Huangliu population （HL） when a-naphthyl acetate （a-NA） and [3-naphthyl acetate were used as substrates, respectively. Such elevated CarEs activities presented in the WD could be because of an increased staining intensity of the a-NA-hydrolyzing CarEs as shown on the nondenaturing polyacrylamide gel electrophoresis. Inhibition studies of CarEs using paraoxon and malaoxon indicated that CarE activities in the HL were more strongly inhibited than those in the WD. Furthermore, a 449-bp DNA fragment of CarE was obtained from L. migratoria manilensis. Hemiquantity reverse transcription-polymerase chain reaction analysis showed that CarE gene expression level in the WD was higher than that in the HL. The higher CarE activities and the increased CarE mRNA level in the WD appeared to be associated with decreased susceptibility to malathion in the WD due to the application of organophosphorus insecticides.

The roles of carboxylesterase and CYP isozymes on the in vitro metabolism of T-2 toxin

Background: T-2 toxin poses a great threat to human health because it has the highest toxicity of the currently known trichothecene mycotoxins. To understand the in vivo toxicity and transformation mechanism of T-2 toxin, we investigated the role of two principal phase Ⅰ drug-metabolizing enzymes(cytochrome P450 [CYP450] enzymes) on the metabolism of T-2 toxin, which are crucial to the metabolism of endogenous substances and xenobiotics. We also investigated carboxylesterase, which also plays an important role in the metabolism of toxic substances.Methods: A chemical inhibition method and a recombinant method were employed to investigate the metabolism of the T-2 toxin by the CYP450 enzymes, and a chemical inhibition method was used to study carboxylesterase metabolism. Samples incubated with human liver microsomes were analyzed by high performance liquid chromatography-triple quadrupole mass spectrometry(HPLC- Qq Q MS) after a simple pretreatment.Results: In the presence of a carboxylesterase inhibitor, only 20% T-2 toxin was metabolized. When CYP enzyme inhibitors and a carboxylesterase inhibitor were both present, only 3% of the T-2 toxin was metabolized. The contributions of the CYP450 enzyme family to T-2 toxin metabolism followed the descending order CYP3A4, CYP2E1, CYP1A2, CYP2B6 or CYP2D6 or CYP2C19.Conclusions: Carboxylesterase and CYP450 enzymes are of great importance in T-2 toxin metabolism, in which carboxylesterase is predominant and CYP450 has a subordinate role. CYP3A4 is the principal member of the CYP450 enzyme family responsible for T-2 toxin metabolism. The metabolite produced by carboxylesterase is HT-2, and the metabolite produced by CYP 3A4 is 3'-OH T-2. The different metabolites show different toxicities. Our results will provide useful data concerning the toxic mechanism, the safety evaluation, and the health risk assessment of T-2 toxin.

Dexamethasone Regulates Differential Expression of Carboxylesterase 1 and Carboxylesterase 2 through Activation of Nuclear Receptors

Carboxylesterases (CESs) play important roles in the metabolism of endogenous and foreign compounds in physiological and pharmacological responses. The aim of this study was to investigate the effect of dexamethasone at different doses on the expression of CES1 and CES2. Imidapril and irinotecan hydrochloride (CPT-11) were used as special substrates for CES1 and CES2, respectively. Rat hepatocytes were cultured and treated with different concentrations of dexamethasone. The hydrolytic activity of CES1 and CES2 was tested by incubation experiment and their expression was quantitated by real-time PCR. A pharmacokinetic study was conducted in SD rats to further evaluate the effect of dexamethasone on CESs activity in vivo. Western blotting was performed to investigate the regulatory mechanism related to pregnane X receptor (PXR) and glucocorticoid receptor (GR). The results showed that exposure of cultured rat hepatocytes to nanomolar dexamethasone inhibited the imidapril hydrolase activity, which was slightly elevated by micromolar dexamethasone. For CES2, CPT-11 hydrolase activity was induced only when dexamethasone reached micromolar levels. The real-time PCR demonstrated that CES1 mRNA was markedly decreased by nanomolar dexamethasone and increased by micromolar dexamethasone, whereas CES2 mRNA was significantly increased by micromolar dexamethasone. The results of a complementary animal study showed that the concurrent administration of dexamethasone significantly increased the plasma concentration of the metabolite of imidapril while the ratio of CPT-11 to its metabolite SN-38 was significantly decreased. PXR protein was gradually increased by serial concentrations of dexamethasone. However, only nanomolar dexamethasone elevated the level of GR protein. The different concentrations of dexamethasone required suggested that suppression of CES1 may be mediated by GR whereas the induction of CES2 may result from the role of PXR. It was concluded that dexamethasone at different concentrations can differentially regulate CES1 and CES2.

Cloning and characterization of a thermostable carboxylesterase from inshore hot spring thermophile Geobacillus sp.ZH1

The gene （741 bp） encoding carboxylesterase from the thermophilic bacterium Geobacillus sp. ZH1 was cloned and overexpressed in Escherichia coll. The purified recombinant protein presented a molecular mass of about 40 kDa by SDS-PAGE analysis. Enzyme assays using p-nitrophenyl esters with different acyl chain lengths as the substrates confirmed its esterase activity, yielding highest specific activity with p-nitrophenyl acetate. Among the p-nitrophenyl esters tested, the carboxylesterase presented preference for p-nitrophenyl caprylate, but hydrolyzed p-nitrophenyl butyrate more efficiently. When p-nitrophenyl butyrate was used as a substrate, the recombinant carboxylesterase exhibited highest activity at pH 8.0 and 60℃. Almost no decrease in esterase activity was observed at 60℃ for 3 h, and over 40% of activity was still maintained after incubation at 90℃ for 3 h. These results indicate that Geobacillus sp. ZH1 recombinant esterase was thermostable. The enzymatic activity was inhibited by the addition of phenylmethylsulfonyl fluoride, indicating that it contains serine residue, which plays a key role in the catalytic mechanism. Except SDS and xylene, this esterase showed stability toward other tested detergents and organic solvents. Cloning, expression, and biochemical characterization of Geobacillus sp. ZH1 carboxylesterase lay a good foundation for its structural characterization and industrial application.

cDNA cloning and characterization of t he carboxylesterase pxCCE016b from the diamondback moth, Plutella xylostella L.

Carboxylesterase is a multifunctional superfamily and can be found in almost all living organisms. As the metabolic enzymes, carboxylesterases are involved in insecticides resistance in insects for long time. In our previous studies, the enhanced c arboxylesterase activities were found in the chlorantraniliprole resistance strain of diamondback moth（DBM）. However, t he related enzyme gene of chlorantraniliprole resistance has not been clear in this strain. Here, a full-length c DNA of carboxylesterase pxCCE016 b was cloned and exogenously expressed in Escherichia coli at the first time, which contained a 1 693 bp open reading frame（ORF） and encoded a protein of 542 amino acids. Sequence analysis showed that this c DNA has a predicted mass of 61.56 k Da and a theoretical isoelectric point value of 5.78. The sequence of deduced amino acid possessed the classical structural features： a type-B carboxylesterase signature 2（EDCLYLNVYTK）, a type-B carboxylesterase serine active site（FGGDPENITIFGESAG） and the catalytic triad（S er186, Glu316, and His444）. The real-time quantitative PCR（q PCR） analysis showed that t he expression level of the p x CCE016 b was significantly higher in the chlorantraniliprole resistant strain than in the susceptible strain. Furthermore, pxCCE016 b was highly expressed in the midgut and epidermis of the DBM larvae. When the 3rd-instar larvae of resistant DBM were exposed to abamectin, alpha-cypermethrin, chlorantraniliprole, spinosad, c hlorfenapyr and indoxacarb insecticides, the up-regulated expression of pxCCE016 b was observed only in the group treated by chlorantraniliprole. In addition, recombinant vector p ET-pxCCE016 b was constructed with the most coding region（1 293 bp） and large number of soluble recombinant proteins（less than 48 k Da） were expressed successfully with prokaryotic cell. Western blot analysis showed that it was coded by pxCCE016 b. All the above findings provide important information for further f unctional study, although we are uncertainty whether the pxCCE016 b gene is actually i nvolved in chlorantraniliprole resistance.

A Study on the Activity of Carboxylesterase and the Differential Expression of Its Gene in the Midguts of Bombyx mori Resistant to BmDNV-Z

This study was to discuss the relationship among the change in the activity of Bombyx mori carboxylesterase （BmCarE） in the midguts, the differential expression of BmCarE gene （bmcare） in the midguts, and the ability of Bombyx mori resistant to densonucleosis virus （BmDNV）, and to elucidate the molecular mechanism of resistance to BmDNV-Z. With two silkworm strains, HUABA, which is susceptible to BmDNV-Z, and BC8 （a near isogenic line of HUABA）, which is completely resistant to the same virus, as materials, the activity of BmCarE in the midgut was determined by Bio-Tek Synergy, and the differential expression of bmcare between the two strains was investigated by real-time fluorescence quantitative PCR, both at 12, 36, and 72 h post oral inoculation of the two strains with virus （hereafter referred as inoculation）. While the activity of BmCarE in the midguts of BC8 inoculation group at 12 h post inoculation was higher than that in the BC8 control group, the HUABA inoculated group, and the HUABA control group by 3.28, 2.26, and 3.02 times, respectively, with the difference being highly significant （P 〈 0.01）, there was no statistical difference among the other groups. The relative expression level of bmcare in the midguts of BC8 inoculation group at 12 h post inoculation was higher than that in the BC8 control group, the HUABA inoculation group, and the HUABA control group by 17.714, 21.76, and 15.09 times, respectively, with the difference being highly significant （P 〈 0.01）, and there was no statistical difference among other groups. The elevation of BmCarE activity and expression level of bmcare in the resistant strain at 12 h post inoculation may relate to the resistant gene （nsd/nsd） and the stimulation of BmDNV-Z. The molecular basis for the elevation of BmCarE activity in the resistant strain BC8 may be the change in the expression level of bmcare.

Characterization of carboxylesterase PxαE8 and its role in multi-insecticide resistance in Plutella xylostella(L.)

Carboxylesterase(CarE)was considered as important phase-I detoxifying enzymes which participated in detoxification of different types of insecticides.Up-regulation of CarE genes has been proved playing a major role in insecticide resistance in many pest insects,but its involvement in resistance to insecticides in Plutella xylostella has been rarely reported.In this study,a CarE cDNA named PxαE8 was identified in P.xylostella,which has an open reading frame of 1599 nucleotides and putatively encodes 532 amino acids.The investigation of spatial expression profiles of PxαE8 revealed that it was expressed in all developmental stages,especially in larvae and adults.The body part/tissue-specific expression profiles showed that the PxαE8 mainly expressed in fat body,malpighian tubule and hemolymph of larvae.Further,the relative expression of PxαE8 in two multi-resistant field populations,Hainan(HN)and Guangdong(GD)populations,was found 24.4-and 15.5-fold higher than that in susceptible population,respectively.Knockdown of PxαE8 by RNA interference dramatically increased the mortalities of larvae of HN population treated with LC_(50) of beta-cypermethrin and phoxim by 25.3 and 18.3%,respectively.These results suggested that up-regulation of PxαE8 was involved in resistance to both beta-cypermethrin and phoxim in P.xylostella,which shed light on further understanding of molecular mechanisms of multi-insecticide-resistance in P.xylostella and other pest insects.

Pharmacogenetics of azathioprine in inflammatory bowel disease: A role for glutathione-S-transferase?

Azathioprine is a purine antimetabolite drug commonly used to treat inflammatory bowel disease (IBD). In vivo it is active after reaction with reduced glutathione (GSH) and conversion to mercaptopurine. Although this reaction may occur spontaneously, the presence of isoforms M and A of the enzyme glutathione-S-transferase (GST) may increase its speed. Indeed, in pediatric patients with IBD, deletion of GST-M1, which determines reduced enzymatic activity, was recently associated with reduced sensitivity to azathioprine and reduced production of azathioprine active metabolites. In addition to increase the activation of azathioprine to mercaptopurine, GSTs may contribute to azathioprine effects even by modulating GSH consumption, oxidative stress and apoptosis. Therefore, genetic polymorphisms in genes for GSTs may be useful to predict response to azathioprine even if more in vitro and clinical validation studies are needed.

Glutathione-S-transferase M1 polymorphisms on the susceptibility to esophageal cancer among three Chinese minorities:Kazakh,Tajik and Uygur

AIM： To investigate the glutathione-S-transferase M1 （GSTM1） polymorphisms in three Chinese minorities, Kazakh, Uygur, and Tajik; and the pathological significance of GSTM1 polymorphisms in esophageal carcinogenesis in Kazakh.METHODS： A total of 1121 blood samples （442 males and 679 females） were obtained from healthy Kazakh （654）, Uygur （412） and Tajik （55）. Primary esophageal squamous cell cancer （ESCC） tissues from Kazakh were obtained from 116 patients who underwent surgery. GSTM1 polymorphisms were analyzed by a combined approach of PCR and electrophoresis techniques.RESULTS： GSTM1 null genotype was found in 62.63% Uygur, 50.91% Tajik and 47.40% Kazakh. A significantly higher frequency of GSTM1 null genotype in Uygur was observed compared with Kazakh （OR： 1.859, 95% CI： 1.445 -2.391, χ^2 = 23.71, P = 0.000）. In addition, GSTM1 null genotype was found in 23.53% of welldifferentiated ESCC in Kazakh, in 49.23% of poorly differentiated ESCC, with a significant difference （OR： 3.152, 95% CI： 1.403-7.080, χ^2 = 8.018, P = 0.007）.CONCLUSION： There is a marked difference in the frequency of common GSTM1 null genotype between Uygur and Kazakh. GSTM1 null genotype is associated with differentiation of ESCC in Kazakh.

Glutathione-S-transferases genes-promising predictors of hepatic dysfunction

diseases pathogenesis are genes that encodes the synthesis of glutathione-Stransferase(GST),known as the second phase enzyme detoxification system that protects against endogenous oxidative stress and exogenous toxins,through catalisation of glutathione sulfuric groups conjugation and decontamination of lipid and deoxyribonucleic acid oxidation products.The group of GST enzymes consists of cytosolic,mitochondrial and microsomal fractions.Recently,eight classes of soluble cytoplasmic isoforms of GST enzymes are widely known:α-,ζ-,θ-,κ-,μ-,π-,σ-,andω-.The GSTs gene family in the Human Gene Nomenclature Committee,online database recorded over 20 functional genes.The level of GSTs expression is considered to be a crucial factor in determining the sensitivity of cells to a broad spectrum of toxins.Nevertheless,human GSTs genes have multiple and frequent polymorphisms that include the complete absence of the GSTM1 or the GSTT1 gene.Current review supports the position that genetic polymorphism of GST genes is involved in the pathogenesis of various liver diseases,particularly non-alcoholic fatty liver disease,hepatitis and liver cirrhosis of different etiology and hepatocellular carcinoma.Certain GST allelic variants were proven to be associated with susceptibility to hepatological pathology,and correlations with the natural course of the diseases were subsequently postulated.

Accurate Assessment and Tracking the Process of Liver-Specific Injury by the Residual Tissue Activity of Carboxylesterase 1 and Dipeptidyl Peptidase 4

Accurately assessing and tracking the progression of liver-specific injury remains a major challenge in the field of biomarker research.Here,we took a retrospective validation approach built on the mutuality between serum and tissue biomarkers to characterize the liver-specific damage of bile duct cells caused by a-naphthyl isothiocyanate(ANIT).We found that carboxylesterase 1(CES1),as an intrahepatic marker,and dipeptidyl peptidase 4(DPP-IV),as an extrahepatic marker,can reflect the different pathophysiologies of liver injury.Levels of CES1 and DPP-IV can be used to identify liver damage itself and the inflammatory state,respectively.While the levels of the conventional serological biomarkers alkaline phosphatase(ALP),alanine aminotransferase(ALT),and aspartate aminotransferase(AST)were all concomitantly elevated in serum and tissues after ANIT-induced injury,the levels of bile acids decreased in bile,increased in serum,and ascended in intrahepatic tissue.Although the level of γ-glutamyl transpeptidase(γ-GT)changed in an opposite direction,the duration was much shorter than that of CES1 and was quickly restored to normal levels.Therefore,among the abovementioned biomarkers,only CES1 made it possible to specifically determine whether the liver cells were destroyed or damaged without interference from inflammation.CES1 also enabled accurate assessment of the anti-cholestasis effects of ursodeoxycholic acid(UDCA;single component)and Qing Fei Pai Du Decoction(QFPDD;multicomponent).We found that both QFPDD and UDCA attenuated ANIT-induced liver damage.UDCA was more potent in promoting bile excretion but showed relatively weaker anti-injury and antiinflammatory effects than QFPDD,whereas QFPDD was more effective in blocking liver inflammation and repairing liver damage.Our data highlights the potential of the combined use of CES1(as an intrahepatic marker of liver damage)and DPP-IV(as an extrahepatic marker of inflammation)for the accurate evaluation and tracking of liver-specific injury—an application that allows for the differentiation of liver damage and inflammatory liver injury.

β-catenin accumulation in nuclei of hepatocellular carcinoma cells up-regulates glutathione-s-transferase M3 mRNA

AIM: To identify the differentially over-expressed genes associated with β-catenin accumulation in nuclei of hepatocellular carcinoma (HCC) cells. METHODS: Differentially expressed genes were identified in radiation-induced B6C3 F1 mouse HCC cells by mRNA differential display, Northern blot and RT-PCR, respectively. Total glutathione-s-transferase (GST) activity was measured by GST activity assay and β-catenin localization was detected with immunostaining in radiation-induced mouse HCC cells and in HepG2 cell lines.RESULTS: Two up-regulated genes, glutamine synthetase and glutathione-s-transferase M3 (GSTM3), were identified in radiation-induced mouse HCC cells. Influence of β-catenin accumulation in nuclei of HCC cells on upregulation of GSTM3 mRNA was investigated. The nearby upstream domain of GSTM3 contained the β-catenin/TcfLef consensus binding site sequences [5'-(A/T)(A/T) CAAAG-3'], and the total GST activity ratio was considerably higher in B6C3F1 mouse HCC cells with β-catenin accumulation in nuclei of HCC cells than in those without β-catenin accumulation (0.353 ± 0.117vs 0.071 ± 0.064, P < 0.001). The TWS119 (a distinct GSK-3β inhibitor)-induced total GST activity was significantly higher in HepG2 cells with β-catenin accumulation than in those without β-catenin accumulation in nuclei of HCC cells. Additionally, the GSTM3 mRNA level was significantly higher at 24 h than at 12 h in TWS119-treated HepG2 cells. CONCLUSION: β-catenin accumulation increases GST activity in nuclei of HCC cells, and GSTM3 may be a novel target gene of the β-catenin/Tcf-Lef complex.

Prognostic Significance of Comparison of Clinical Indicators with Manifestations of Genetic Polymorphism of Glutathione-S-Transferases in Non-Small Cell Lung Cancer

The article presented the results of comparison of polymorphic variants of the genes GSTM1, GSTT1, GSTP1 and clinical manifestations of non-small cell lung carcinoma. The association of the genotype GSTT1 (del) with the risk of developing squamous cell lung cancer has been revealed (OR = 2.54 CI: 1.13 - 5.72, p = 0.035). Analysis of patient survival rate (n = 173) in groups of various histological types of lung cancer showed that in the group of squamous cell lung cancer (n = 91) in patients with genotype GSTT1 (del), the survival rate median was significantly higher—84 months (95% CI 12.4 - 155.7) than in patients with the genotype GSTT1 (+)—36 months (95% CI 25.2 - 46.8, p = 0.045). In contrast, in the adenocarcinoma group (n = 82), the survival rate median in patients with the genotype GSTT1 (del) was 19 months. (95% CI 6.2 - 33.5), and in patients with genotype GSTT1 (+)—67 months (95% CI 50.1 - 84.0), which is the basis for continuing this comparison in an additional group of testees, as the sampling did not achieve the reliability of p = 0.12. Hypothetically, these differences may be due to differences in the gender composition of squamous cell lung cancer and adenocarcinoma and the involvement of GST enzymes in the metabolism of estrogens in adenocarcinoma in women and other hormonal background and reactivity of the male body with squamous cell carcinoma. Further research and subsequent analysis of the results will be aimed at confirming this hypothesis.

Evaluation of Glutathione-S-transferase and ceruloplasmin levels in gingival crevicular fluid and gingival tissue as diagnostic markers for chronic periodontitis

Periodontitis, is an infectious ailment of multifactorial origin, that brings about destruction of bone and surrounding tissues. There are various oral pathogens that may be responsible for the destruction. The host encounters these microbial invasions and their products by the production and release of inflammatory mediators from the cells within the body. Glutathione-S-transferase (GST) are a group of enzymes that utilize glutathione in conditions resulting in oxidative stress. These enzymes play a key role in the detoxifycation of such substance. It aids in preventing damage to important cellular components caused by release of free reactive oxygen species. Ceruloplasmin is a ferroxidase enzyme. It plays a role as an anti-inflammatory agent, by its ability to scavenge free radicals within the body. The present study was targeted at evaluating the levels of Glutathione-S-Transferase (GST) and Ceruloplasmin as diagnostic markers for patients with chronic periodontitis in gingival crevicular fluid (GCF) and the gingival tissues. Thirty patients were divided into two groups. Experimental group comprising of 15 subjects with chronic perio- dontitis and the control group was composed of 15 healthy individuals. Highly significant changes in GST between the diseased and normal patients (P = 0.001) were detected. There was a decrease in GST level in both gingival tissue & GCF in diseased patients when compared to the control patients. The ceruloplasmin levels in GCF and gingival tissues showed no difference between the control and diseased group. Hence,these results indicate a relationship suggesting that GST produced during chronic inflammation could be used as biomarker that indicate periodontal disease .

Characterization of a Thermostable, Recombinant Carboxylesterase from the Hyperthermophilic Archaeon <em>Metallosphaera sedula</em>DSM5348

Lipid-producing microalgae are emerging as the leading platform for producing alternative biofuels in response to diminishing petroleum reserves. Optimization of fatty acid production is required for efficient conversion of microalgal fatty acids into usable transportation fuels. Microbial lipases/esterases can be used to enhance fatty acid production because of their efficacy in catalyzing hydrolysis of esters into alcohols and fatty acids while minimizing the potential poisoning of catalysts needed in the biofuel production process. Although studies have extensively focused on lipases/esterases produced by mesophilic organisms, an understanding of lipases/esterases produced by thermophilic, acidic tolerant microbes, such as Metallosphaera sedula, is limited. In this work, the carboxylesterase from Metallosphaera sedula DSM5348 encoded by Msed_1072 was recombinantly expressed in Escherichia coli strain BL21 (λDE3). The purified enzyme either with a hexahistidine (His6)-tag (Msed_1072Nt and Msed_1072Ct) or without the hexahistidine (His6)-tag (Msed_1072) was biochemically characterized using a variety of substrates over a range of temperatures and pH and in the presence of metal ions, organic solvents, and detergents. In this study, the fusion of the protein with a hexahistidine (His6)-tag did not result in a change in substrate specificity, but the findings provide information on which enzyme variant can hydrolyze fatty acid esters in the presence of various chemicals, and this has important implication for their use in industrial processes. It also demonstrates that Metallosphaera sedula Msed_1072 can have application in microalgae-based biofuel production systems.

Immunoprophylactic potential of filarial glutathione-s-transferase in lymphatic filariaisis

Objective:To elucidates the immunoprophylactic potential of glutathion-s-transferase(GST) from cattle filarial parasite Setaria digitata(S.digitata) against lymphatic filariasis.Methods: GST was purified through affinity chromatography(SdGST) and chacterized by SDS-PAGE and Nano-LC MS/MS analysis.Antibody isotypes to SdGST were measured by ELISA.Antibody dependant cellular cytotoxicity(ADCC) was performed in vitro using sera from immunized animals and immune individuals.T-cell proliferation and cytokine response to SdGST in different groups of filariasis were measured.Immunoprophylactic potential of SdGST was evaluate in animal model.Results:SdGST exhibited 30-fold enhancement of enzyme activity over crude parasitic extract.It was found to be 26 kDa by SDS-PAGE.Nano LC-MS/MS analysis followed by blast search showed 100%homology with Dirqfilaria immitis(D.immitis) and only 43%with Homo sapiens(H.sapiens).Immunoblotting analysis showed putatively immune individuals carry significant level of antibodies to SdGST as compared with microfilaraemics.Immunized sera and sera endemic normal could neutralize the enzymatic activity of SdGST and inducing in vitro cytotoxicity of microfilariae.Peripheral blood mononuclear cells(PBMC) from endemic normals upon stimulation with SdGST showed a mixed type of Th1/Th2 response.SdGST immunization clear microfilariae from circulation in S.digitata implanted mastomys.Conclusions:The heterologous GST could be potentially developed as a vaccine candidate against lymphatic filarial parasite.

Cisplatin increases carboxylesterases through increasing PXR mediated by the decrease of DEC1

cis-Diamminedichloroplatinum(CDDP)is widely used for the treatment of various solid cancers.Here we reported that CDDP increased the expression and enzymatic activities of carboxylesterase 1(CES1)and carboxylesterase 2(CES2),along with the upregulation of pregnane X receptor(PXR)and the downregulation of differentiated embryonic chondrocyte-expressed gene 1(DEC1)in human hepatoma cells,primary mouse hepatocytes,mouse liver and intestine.The overexpression or knockdown of PXR alone upregulated or downregulated the CES1 and CES2 expression,respectively.The increases in CES1 and CES2 expression levels induced by CDDP abolished or enhanced by PXR knockdown or overexpression,implying that CDDP induces carboxylesterases through the activation of PXR.Likewise,the overexpression or knockdown of DEC1 alone significantly decreased or increased PXR and its targets.Moreover,the increases of PXR and its targets induced by CDDP were abolished or alleviated by the overexpression or knockdown of DEC1.The overexpression or knockdown of DEC1 affected the response of PXR to CDDP,but not vice versa,suggesting that CDDP increases carboxylesterases by upregulating PXR mediated by the decrease of DEC1.In addition,CDDP did not increase DEC1 mRNA degradation but suppressed DEC1 promoter reporter activity,indicating that it suppresses DEC1 transcriptionally.The combined use of CDDP and irinotecan had a synergistic effect on two cell lines,especially when CDDP was used first.