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Publication
Journal: Molecular Reproduction and Development
November/5/2017
Abstract
Early mammalian embryos derived from in vitro fertilization are exposed to conditions distinct from the native oviduct-uterine environment, including atmospheric oxygen that promotes cellular oxidative stress and alters gene expression. High oxygen partial pressure during embryo development is associated with low pregnancy rates and increased embryonic apoptosis. We investigated how bovine embryos responded to high (20%) or low (5%) oxygen partial pressure during in vitro culture, evaluating levels of reactive oxygen species (ROS) as well as changes in the expression of oxidative stress- and epigenetic-related transcripts and miRNAs in blastocysts. Additionally, we determined the global DNA methylation levels in the resulting embryos. Our data indicated that bovine blastocysts produced in vitro under high oxygen partial pressure possessed elevated ROS abundance and exhibited increased expression of CAT, GLRX2, KEAP1, NFR2, PRDX1, PRDX3, SOD1, TXN, and TXNRD1, versus reduced levels of the oxidative stress-related bta-miR-210. These stressed embryos also presented altered expression of the epigenetic-associated transcripts DNMT3A, H2AFZ, H3F3B, HDAC2, MORF4L2, REST, and PAF1. In addition, we demonstrated that embryos cultured under high oxygen partial pressure have increased global DNA methylation, suggesting that DNA hypermethylation is mediated by the deregulation of epigenetic-related enzymes due to oxidative stress.
Publication
Journal: Laryngoscope
October/28/1982
Abstract
Retrospective review of 118 primarily treated cancers of the oral tongue was done to study patient selection and to search for improved treatment strategies. Small surface lesions were treated by local excision (LE); most small lesions invading muscle of the tongue without lymph node metastases were treated by radiation alone (RA) while larger lesions and those with palpable nodes were treated by preoperative radiation and surgery (R + S). Ultimate control of the primary tumor and lymph nodes after initial treatment and surgical salvage was high for the lesions by LE (91%), the T1N0 lesions treated by RA (88%) and for the TxN+ lesions treated by R + S (57%). Improved treatment strategies are suggested for T2N0 lesions treated by RA because of poor tumor control (53%) and a high rate of radiation complications (25%), and for T3N0 lesions because so many of these patients died from causes other than cancer within two years. Second primary cancers were most common in those patients with a good prognosis.
Publication
Journal: Molecular Nutrition and Food Research
November/22/2019
Abstract
We previously showed that two hydrogenated xanthohumol (XN) derivatives, α,β-dihydro-XN (DXN) and tetrahydro-XN (TXN), improved parameters of metabolic syndrome (MetS), a critical risk factor of cardiovascular disease (CVD) and type 2 diabetes, in a diet-induced obese murine model. We hypothesized that improvements in obesity and MetS are linked to changes in the composition of the gut microbiota, bile acid metabolism, intestinal barrier function and inflammation.To test this hypothesis, we sequenced 16S rRNA genes and measured bile acids in fecal samples from C57BL/6J mice fed a high-fat diet (HFD) or HFD containing XN, DXN or TXN. We measured the expression of genes associated with epithelial barrier function, inflammation, and bile acid metabolism, in the colon, white adipose tissue (WAT), and liver, respectively. Administration of XN derivatives decreased intestinal microbiota diversity and abundance, specifically Bacteroidetes and Tenericutes, altered bile acid metabolism, and reduced inflammation. In WAT, TXN supplementation decreased pro-inflammatory gene expression by suppressing macrophage infiltration. Transkingdom network analysis connected changes in the microbiota to improvements in MetS in the host.Changes in the gut microbiota and bile acid metabolism may explain, in part, the improvements in obesity and MetS associated with administration of XN and its derivatives. This article is protected by copyright. All rights reserved.
Publication
Journal: Environmental Science and Pollution Research
November/13/2018
Abstract
The influence of tramadol (TD) on hepatic tissue and the potential efficiency of lycopene to mitigate TD-induced hepatotoxic impacts were determined. Forty male albino rats were allocated into four groups: group I, untreated (placebo); group II, injected with TD (15 mg kg-1) intraperitoneally (i.p.); group III, gastrogavaged with lycopene (10 mg kg-1) per os (p.o.); and group IV received TD with lycopene with the same mentioned doses for 15 days. The results demonstrated that TD induced augmentation in tissue lipid peroxidation biomarker and disturbance in the antioxidant homeostasis and elevated the activity of serum liver injury biomarkers and decreased serum protein, globulin, and albumin. Hepatic glutathione S-transferase (GST), superoxide dismutase (SOD), thioredoxin-1 (Txn-1), and catalase (CAT) activities and gene expression were decreased and glutathione content was reduced in the TD-challenged rats, and these effects were alleviated by lycopene. Furthermore, TD induced apoptosis in liver tissues as shown by DNA fragmentation and upregulation of proapoptotic Bax and Casp-3 while lycopene upregulated the antiapoptotic Bcl-2. The results of Western blot showed that lycopene initiated low expression of mitogen activated protein kinase pathway (MAPK) protein expression in liver tissues of TD-challenged rats. In addition, lycopene reduced fatty degeneration and necrosis of the liver in TD-challenged group. Our data demonstrate that lycopene appears to be highly efficient in mitigating the hepatotoxic impacts of TD by preventing lipid peroxidation and initiating modifications in the expression and activity of antioxidant pathways. Surprisingly, lycopene fortified liver tissue by inhibiting DNA fragmentation and apoptosis signaling induced by TD. MAPK activation may be dependent from ROS generation; due to lycopene which possessed antioxidant potential did have a substantial effect on MAPK activity.
Publication
Journal: Biomarker Insights
May/6/2017
Abstract
The molecular basis of the pathophysiological role of oxidative stress in autism is understudied. Herein, we used polymerase chain reaction (PCR) array to analyze transcriptional pattern of 84 oxidative stress genes in peripheral blood mononuclear cell pools isolated from 32 autistic patients (16 mild/moderate and 16 severe) and 16 healthy subjects (each sample is a pool from 4 autistic patients or 4 controls). The PCR array data were further validated by quantitative real-time PCR in 80 autistic children (55 mild/moderate and 25 severe) and 60 healthy subjects. Our data revealed downregulation in GCLM, SOD2, NCF2, PRNP, and PTGS2 transcripts (1.5, 3.8, 1.2, 1.7, and 2.2, respectively; P < .05 for all) in autistic group compared with controls. In addition, TXN and FTH1 exhibited 1.4- and 1.7-fold downregulation, respectively, in severe autistic patients when compared with mild/moderate group (P = .005 and .0008, respectively). This study helps in a better understanding of the underlying biology and related genetic factors of autism, and most importantly, it presents suggested candidate biomarkers for diagnosis and prognosis purposes as well as targets for therapeutic intervention.
Publication
Journal: Avian Pathology
September/22/2010
Abstract
Newcastle disease is an important viral infectious disease caused by Newcastle disease virus (NDV), which leads to severe economic losses in the poultry industry worldwide. The molecular mechanisms involved in the pathogenesis of NDV and the host-directed antiviral responses remain poorly understood. In this study, we screened and identified the differentially expressed transcripts from chicken spleen 36 h post NDV infection using suppression subtractive hybridization (SSH). From the SSH library, we obtained 140 significant differentially expressed sequence tags (ESTs), which could be divided into three categories: high homology genes (58), high homology ESTs (62) and novel ESTs (20). The 58 high homology genes could be grouped into nine clusters based on the best known function of their protein products, which involved signalling transduction (HSPC166, PDE7B, GRIA4, GARNL1), transcriptional regulation (ANP32A, LOC423724, SATB1, QKI, ETV6), cellular molecular dynamics (MYLK, MYO7A, DCTN6), cytoskeleton (LAMA4, LAMC1, COL4A1), stress response (DNAJC15, CIRBP), immune response (TIA1, TOX, CMIP), metabolism (RPS15A, RPL32, GLUT8, CYPR21, DPYD, LOC417295), oxidation-reduction (TXN, MSRB3, GCLC), and others. In addition, we found that the 20 novel ESTs provide a clue for the discovery of some new genes associated with infection. In summary, our findings demonstrate previously unrecognized changes in gene transcription that are associated with NDV infection in vivo, and many differentially expressed genes identified in the study clearly merit further investigation. Our data provide new insights into better understanding the molecular mechanism of host-NDV interaction.
Publication
Journal: Toxicology in Vitro
April/22/2020
Abstract
Nowadays, there is a huge interest in natural products obtained from marine organisms that can promote human health.The aim of the present study is to evaluate for the first time, the in vitro effects of marine Aspergillus puulaauensis TM124-S4 extract against oxidative stress in human fibroblasts, and its potential as a cosmetic ingredient. The strain was isolated from the Mediterranean Sea star, Echinaster sepositus, and identified according to ITS molecular sequence homology as a member of Aspergillus section versicolores.To gain insight on the bioactivity underpinning the effects of TM124-S4 extracts on oxidative stress, we examined a panel of a hundred genes as well as cell viability. Initially, Aspergillus puulaauensis TM124-S4 promoted cell viability.The change in gene transcripts revealed that Aspergillus puulaauensis TM124-S4 extracts exhibited skin protection properties by mediating cell proliferation (EPS8, GDF15, CASP7, VEGFA), antioxidant response (CAT, SOD1, TXN, GPX1), skin hydration (CD44, CRABP2, SERPINE) and DNA repair (PCNA, p21). The extract also modulated the expression of genes involved in skin pigmentation and aging (TYR, FOXO3).These findings indicate that Aspergillus puulaauensis TM124-S4 extracts possess significant in-vitro skin protection activity against induced oxidative stress.Furthermore, new insights are provided into the beneficial role of fungal bioactive compounds in skin related research.
Publication
Journal: Oncotarget
November/12/2018
Abstract
Peroxiredoxin-1 (Prdx1), a member of the thioredoxin (Txn) system, is overexpressed and correlates with poor prognosis in pancreatic cancer patients and can suppress Kras signaling through redox-mediated inhibition of ERK and AKT in lung and breast cancer. Its redox function is maintained by Txn and sulfiredoxin (Srxn), and its tumor promoting functions are activated by post-translational modification. We studied the role of the Txn system in pancreatic neoplasia and cancer by determining how it regulates the phosphorylation of Kras effectors and by determining its association with patient survival. We found that elevated Prdx1 nuclear localization significantly correlated with better patient survival. Our data also demonstrate that the expression of the Txn system is dysregulated, with elevated Prdx1 expression and significantly decreased Txn and Srxn expression in pancreatic lesions of targeted mutant Kras mouse models. This correlated with distinct differences in the interconversion of Prdx1 oligomers that affect its ability to regulate ERK and AKT phosphorylation. Our data also suggest that Prdx1 post-translational modification and oligomerization suppress Prdx1 mediated redox regulation of ERK phosphorylation. We observed distinct differences in Txn expression and in the ability of pTyr-Prdx1 to bind to pERK in a PanIN model of pancreatic neoplasia as compared to an IPMN model, indicating a distinct difference in the function of post-translationally modified Prdx1 in cells with less Txn expression. Modified Txn system function and post-translational regulation may therefore play a significant role in pancreatic tumorigenesis by altering Kras effector phosphorylation and inhibiting the tumor suppressive redox functions of Prdx1.
Publication
Journal: International Journal of Molecular Sciences
April/2/2021
Abstract
Thioredoxin-interacting protein (TXNIP), widely known as thioredoxin-binding protein 2 (TBP2), is a major binding mediator in the thioredoxin (TXN) antioxidant system, which involves a reduction-oxidation (redox) signaling complex and is pivotal for the pathophysiology of some diseases. TXNIP increases reactive oxygen species production and oxidative stress and thereby contributes to apoptosis. Recent studies indicate an evolving role of TXNIP in the pathogenesis of complex diseases such as metabolic disorders, neurological disorders, and inflammatory illnesses. In addition, TXNIP has gained significant attention due to its wide range of functions in energy metabolism, insulin sensitivity, improved insulin secretion, and also in the regulation of glucose and tumor suppressor activities in various cancers. This review aims to highlight the roles of TXNIP in the field of diabetology, neurodegenerative diseases, and inflammation. TXNIP is found to be a promising novel therapeutic target in the current review, not only in the aforementioned diseases but also in prolonged microvascular and macrovascular diseases. Therefore, TXNIP inhibitors hold promise for preventing the growing incidence of complications in relevant diseases.
Keywords: TXNIP; TXNIP modulator; metabolic disorders; neurological disorders; thioredoxin.
Publication
Journal: Journal of Inorganic Biochemistry
September/27/2017
Abstract
Thioredoxin (Txn) system is the most crucial antioxidant defense mechanism in myocardium. The aim of this study was to clarify the effect of Txn low expression on 25 selenoproteins in chicken cardiomyocytes. We developed a Se-deficient model (0.033mg/kg) and Txn knock down cardiomyocytes model (siRNA) studies. Western Blot, Quantitative Real-time PCR (qPCR) were performed, and correlation analysis, heat map were used for further analysis. Both low expression of Txn models are significantly decreased (P<0.05) the mRNA levels of Deiodinase 1, 2 (Dio 1, 2), Glutathione Peroxidase 1, 2, 3, 4 (Gpx 1, 2, 3, 4), Thioredoxin Reductase 1, 2, 3 (TR 1, 2, 3), Selenoprotein t (Selt), Selenoprotein w (Selw), Selenoprotein k (Selk), selenoprotein x1 (Sepx1), and significantly increased (P<0.05) the mRNA levels of the rest of selenoproteins. Correlation analysis showed that Deiodinase 3 (Dio 3), Selenoprotein m (Selm), 15-kDa Selenoprotein (Selp15), Selenoprotein h (Selh), Selenoprotein u (Selu), Selenoprotein i (Seli), Selenoprotein n (Seln), Selenoprotein p1 (Sepp1), Selenoprotein o (Selo), Selenoprotein s (Sels), Selenoprotein synthetase 2 (Sels2) and Selenoprotein p (Selp) had a negative correlation with Txn, while the rest of selenoproteins had a positive correlation with Txn. Combined in vivo and in vitro we can know that hamper Txn expression can inhibit Gpx 1, 2, 3, 4, TR 1, 2, 3, Dio 1, 2, Selt, Selw, Selk, Sepx1, meanwhile, over expression the rest of selenoproteins. In conclusion, the different selenoproteins possess and exhibit distinct responses to silence of Txn in chicken cardiomyocytes.
Publication
Journal: British Journal of Clinical Pharmacology
May/28/1997
Abstract
OBJECTIVE
Despite widespread use of azathioprine in organ transplant recipients, the mechanism of its myelotoxicity remains unclear. The aim of this study was to assess the importance of thiopurine metabolites on bone marrow toxicity.
METHODS
We investigated the relationship between intracellular concentrations of 6-thioguanine (6-TGN), 6-mercaptopurine (6-MPN) and 6-thioxanthine (6 TXN) nucleotides and the absolute count of white or red cells in forty-seven lung or heart/lung transplant patients after oral administration of azathioprine.
RESULTS
No significant correlation between red cell concentrations of 6-TGN or total thiopurine metabolites and white or red cell counts was found, with no difference between the sexes. Likewise, high 6-TGN levels were not related to bone marrow depletion.
CONCLUSIONS
These results suggest that red blood cell 6-TGN alone do not predict the haematopoietic toxicity of azathioprine.
Publication
Journal: Current Oncology
January/8/2021
Abstract
Background and objectives: the total neoadjuvant chemoradiotherapy (TNT) includes different strategies, but the most appropriate model remains uncertain. The purpose of this retrospectively study was to evaluate the safety and pathological response in the consolidation chemotherapy model.
Methods: patients with cT3/T4 or TxN + M0 rectal cancer that were receiving neoadjuvant chemoradiotherapy (CRT) (50 Gy with oral capecitabine)/TNT (CRT followed by three cycles of CAPOX) during September 2017 to September 2019 in our department were included. All of the patients were recommended to receive radical surgery.
Results: a total of 197 patients were included. Eighty-one patients received CRT, while one hundred and sixteen patients received TNT. Nine patients did not undergo surgery because of the distant metastases (one patient (1.2%) in CRT group, two patients (1.7%) in TNT group) or a refusal of resection (two patients in CRT group, four patients in TNT group). The pathological complete response (pCR) rate was 32.7% in TNT compared with 12.8% in CRT (p = 0.002). There was no statistically significant difference in grade 3 acute toxicities of neoadjuvant treatment and surgical complications between the two groups.
Conclusions: the consolidation chemotherapy model is safe for patients with locally advanced rectal cancer and it has a high pCR rate. The long-term follow-up is necessary to be evaluated in a future prospective, randomized trial.
Keywords: consolidation chemotherapy; pathological complete response; rectal cancer; total neoadjuvant chemoradiotherapy.
Publication
Journal: Proteomics
December/13/2016
Abstract
Mesangial proliferative nephritis (MesPGN) is a common kidney disease worldwide. The main feature of the disease is mesangial cell proliferation-induced injury to kidney function. In this study, we explored serum biomarkers for kidney function injury in anti-Thy1 nephritis. We found that mesangial proliferation were increased on days 5 and 7, and recovered by day 14 in anti-Thy1 nephritis. 24-h urine protein, the ratio of urine protein to urine creatine, serum creatine, and blood urea nitrogen, were increased at days 5 and 7 in the model. We found that TXN, BET1, PrRP, VGF, and NPS differed strongly from controls on days 5 and, associated with kidney injury when detected by SELDI-TOF MS. Moreover, we applied LC-MS to detect differential protein expression and found A2M, C3, ITIH4, ITIH3, VDBP, AFM, and SERPINF2 to be upregulated, and ES1, HPX, SERPINC1, SERPINA1F, SERPINA4, SERPINA3K, SPI, TF, VNN3, SERPINF1, and PON1 to be downregulated, on days 5 and 7, associated with kidney injury. The levels of VNN3 and VDBP were validated by Western blotting. Overall, this study explored a group of candidate biomarkers of mesangial proliferation inducing kidney injury, to provide the basis of an assessment model for MesPGN in the future.
Publication
Journal: Journal of Gastrointestinal Surgery
March/4/2020
Abstract
A high rate of postoperative recurrence, especially early recurrence (ER) occurring within 1 year, seriously impedes patients with hepatocellular carcinoma (HCC) from achieving long-term survival. This study aimed to establish a genomic-clinicopathologic nomogram for precisely predicting ER in HCC patients after R0 resection.Two reliable datasets from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases were selected as the training and validation cohorts, respectively. The prognostic genes related to ER were screened out by univariate Cox regression analysis and differential expression analysis. The gene-based prognostic index was constructed using LASSO and Cox regression analyses, and its independent prognostic value was assessed by Kaplan-Meier and multivariate Cox analyses. Gene set enrichment analysis (GSEA) was performed to explore the biological pathways related to the prognostic index. Finally, the nomogram integrating all the independent prognostic factors was established and comprehensively evaluated by calibration plots, the C-index, receiver operating characteristic curves, and decision curve analysis.Nine dysregulated and prognostic genes related to ER (ZNF131, TATDN2, TXN, DDX55, KPNA2, ZNF30, TIMELESS, SFRP1, and COLEC11) were identified (all P < 0.05). The prognostic index model based on the 9 genes was successfully constructed using the TCGA cohort and showed a certain capability to discriminate the ER group from the non-ER group (P < 0.05) and good independent prognostic value in terms of predicting poor early recurrence-free survival (P < 0.05). Eight biological pathways significantly related to ER were identified by GSEA, such as "cell cycle", "homologous recombination" and "p53 signaling pathway." The genomic-clinicopathologic nomogram integrating the 9-gene-based prognostic index and TNM stage displayed significantly higher predictive accuracy and clinical application value than that of TNM stage model both in the training and validation cohorts (all P < 0.05).The novel genomic-clinicopathologic nomogram may be a convenient and powerful tool for accurately predicting ER in HCC patients after R0 resection.
Publication
Journal: Animal Genetics
December/17/2014
Abstract
The Göttingen Minipig (GMP) developed at the University of Göttingen is a synthetic breed that is widely used in medical research and toxicology. It combines the high fertility of the Vietnamese potbellied pig, the low body weight of the Minnesota Minipig and the white coat colour of the German Landrace pig. The aim of this study was to find genomic regions that may have undergone selection since the creation of the breed in the 1960s. Therefore, the whole genome was screened for footprints of recent selection based on single nucleotide polymorphism (SNP) genotypes from the Illumina Porcine SNP60 BeadChip using two methods: the extended haplotype homozygosity (EHH) test and the estimation of the genomic proportion of the three original breeds at each SNP using a Bayesian approach. Local deviations from the average genome-wide breed composition were tested with a permutation-based empirical test. Results for a comprehensive whole-genome scan for both methods are presented. Several regions showing the highest P-values in the EHH test are related to breeding goals relevant in the GMP, such as growth (SOCS2, TXN, DDR2 and GRB10 genes) and white colour (PRLR gene). Additionally, the calculated proportion of the founder breeds diverged significantly in many regions from the pedigree-based expectations and the genome average. The results provide a genome-wide map of selection signatures in the GMP, which leads to a better understanding of selection that took place over the last decades in GMP breed development.
Publication
Journal: Gene
February/28/1995
Abstract
Thioredoxins (TXN) are small proteins with various biological functions, such as redox regulation, found in many species including bacteria, plants and animals. We previously reported the isolation of the TXN-encoding cDNAs from human and mouse. In order to elucidate the functions of the mammalian TXN system, we planned to generate Txn knockout mice, and cloned the genomic DNA fragments using the Txn cDNA as a probe. The Txn gene extends over 12 kb and consists of five exons separated by four introns. Detailed Southern analyses revealed that the mouse genome contains only one active Txn gene and one processed pseudogene (Txn-ps1), in contrast to some species which have families of active TXN-encoding genes. These findings should help to understand Txn itself, and provide a basis for transgenic experiments by gene targeting.
Publication
Journal: Chinese Journal of Lung Cancer
October/1/2012
Abstract
BACKGROUND
With the most recent introduction of microarray technology to biology, it becomes possible to perform comprehensive analysis of gene expression in cancer cell. In this study the laser microdissection technique and cDNA microarray analysis were combined to obtain accurate molecular profiles of lymphatic metastasis in patients with lung squamous cell carcinoma.
METHODS
Primary lung squamous cancer tissues and regional lymph nodes were obtained from 10 patients who underwent complete resection of lung cancer. According to the source of lung cancer cells, the samples were classified into three groups: the primary tumor with lymphatic metastasis (TxN+, n=5), the primary tumor without lymphatic metastasis (TxN-, n=5) and matched tumor cells from metastatic lymph nodes (N+, n=5). Total RNA was extracted from laser microdissected tumor samples. Adequate RNA starting material of mRNA from primary tumor or metastatic nodes were labeled and then hybridized into the same microarray containing 6 000 known, named human genes/ESTs. After scanning, data analysis was performed using GeneSpring6.2.
RESULTS
A total of 37 genes were found to be able to separate TxN+ from TxN-. TxN+ have higher levels of genes concerned with structural protein, signal transducer, chaperone and enzyme. TxN- have higher levels of genes coding for cell cycle regulator, transporter, signal transducer and apoptosis regulator. Interestingly, there were no differentially expressed genes between N+ and TxN+.
CONCLUSIONS
The acquisition of the metastatic phenotype might occur early in the development of lung squamous cancer. We raise the hypothesis that the gene-expression signature described herein is valuable to elucidate the molecular mechanisms regarding lymphatic metastasis and to look for novel therapeutic targets.
Publication
Journal: Revue du Praticien
February/15/2011
Abstract
Individual screening of patients with personal or family history of colon cancer or polyps, or patients with an inflammatory condition of the digestive tract, combined with the generalization of mass screening using Hemoccult, have modified the way colon cancer is diagnosed. The optimization of colon surgery, together with adjuvant chemotherapy, has improved the 5- and 10-year survival. The five-year survival rate is now comprised between 90 percent in patients with stage-I colon cancer, and 65-70 percent in patients with stage-III colon cancer. More than half patients suffer from stage-II (T3-T4 N0) or stage-III (TxN+) cancer, and 30 to 40 percent of these patients experience cancer recurrence without adjuvant therapy within 5 years following surgery. In patients with surgically-resected colon cancer, these recurrences are mostly metastatic (liver, lungs, peritoneum), local recurrences remain uncommon. Metastases are secondary to microscopic tumor foci disseminated away from the primary tumor, non detectable before and during surgery. An adjuvant therapy combining oxaliplatin and fluoropyrimidine is clearly indicated in patients with stage-III colon tumor (20-percent improvement of survival without recurrence), and can be considered in stage-III patients. This treatment is not indicated in patients with stage-I tumor.
Publication
Journal: Biochimica et Biophysica Acta - General Subjects
March/10/2015
Abstract
BACKGROUND
The principal oxidative-stress defense in the human parasite Trypanosoma cruzi is the tryparedoxin-dependent peroxide detoxification pathway, constituted by trypanothione reductase (TryR), tryparedoxin (TXN), tryparedoxin peroxidase (TXNPx) and tryparedoxin-dependent glutathione peroxidase A (GPxA). Here, Metabolic Control Analysis (MCA) was applied to quantitatively prioritize drug target(s) within the pathway by identifying its flux-controlling enzymes.
METHODS
The recombinant enzymes were kinetically characterized at physiological pH/temperature. Further, the pathway was in vitro reconstituted using enzyme activity ratios and fluxes similar to those observed in the parasites; then, enzyme and substrate titrations were performed to determine their degree of control on flux. Also, kinetic characterization of the whole pathway was performed.
RESULTS
Analyses of the kinetic properties indicated that TXN is the less efficient pathway enzyme derived from its high Kmapp for trypanothione and low Vmax values within the cell. MCA established that the TXN-TXNPx and TXN-GPxA redox pairs controlled by 90-100% the pathway flux, whereas 10% control was attained by TryR. The Kmapp values of the complete pathway for substrates suggested that the pathway flux was determined by the peroxide availability, whereas at high peroxide concentrations, flux may be limited by NADPH.
CONCLUSIONS
These quantitative kinetic and metabolic analyses pointed out to TXN as a convenient drug target due to its low catalytic efficiency, high control on the flux of peroxide detoxification and role as provider of reducing equivalents to the two main peroxidases in the parasite.
CONCLUSIONS
MCA studies provide rational and quantitative criteria to select enzymes for drug-target development.
Publication
Journal: Gastroenterology and Hepatology from Bed to Bench
September/18/2019
Abstract
Screening differentially expressed genes (DEGs) related to Eosinophilic gastroenteritis (EG) to introduce possible biomarkers.EG as a rare gastrointestinal disorder is characterized with gastrointestinal bleeding, crampy generalized abdominal pain, diarrhea, nausea, vomiting, and weight loss. In this study gene expression profile of patients is analysis via protein-protein interaction (PPI) analysis to reveal new prospective of disease.Top significant genes of gene expression profiles of 5 gastric antrum EG patients and 5gastric antrum control from GEO which were matched via boxplot analysis were screened via PPI network by using Cytoscape software and STRING database. Numbers of 20 top nodes of query DEGs based on degree value were introduced as central nodes which 7 critical central genes among them were identified. Gene ontology enrichment for the 20 central genes was done by using CluGO. Action map for the central genes was performed by applying CluePedia.Among 20 central nodes, TXN, PRDX2, NR3C1, GRB2, PIK3C3, AP2B1 and REPS1 were recognized as critical central genes. Nine biological terms were determined that most of them were involved in the transport processes.The introduced possible biomarkers can be used in the differential diagnosis of the disease and also in treatment of disorder.
Publication
Journal: Redox Biology
June/16/2019
Abstract
Trypanothione (T(SH)2) is the main antioxidant metabolite for peroxide reduction in Trypanosoma cruzi; therefore, its metabolism has attracted attention for therapeutic intervention against Chagas disease. To validate drug targets within the T(SH)2 metabolism, the strategies and methods of Metabolic Control Analysis and kinetic modeling of the metabolic pathway were used here, to identify the steps that mainly control the pathway fluxes and which could be appropriate sites for therapeutic intervention. For that purpose, gamma-glutamylcysteine synthetase (γECS), trypanothione synthetase (TryS), trypanothione reductase (TryR) and the tryparedoxin cytosolic isoform 1 (TXN2 synthesis by 60-74% and 15-31%, respectively. γECS overexpression prompted up to a 3.5-fold increase in T(SH)2 concentration, whereas TryS overexpression did not render an increase in T(SH)2 levels as a consequence of high T(SH)2 degradation. The peroxide reduction flux was controlled for 64-73% by TXNTXNPx and 11-16% by TryR. TXN2O2 resistance, whereas TXNTXN increased trypomastigote bursting. The present data suggested that inhibition of high controlling enzymes such as γECS and TXN2 antioxidant pathway may compromise the parasite's viability and infectivity.
Publication
Journal: BMC Genomics
June/30/2016
Abstract
BACKGROUND
The avian eggshell membranes surround the egg white and provide a structural foundation for calcification of the eggshell which is essential for avian reproduction; moreover, it is also a natural biomaterial with many potential industrial and biomedical applications. Due to the insoluble and stable nature of the eggshell membrane fibres, their formation and protein constituents remain poorly characterized. The purpose of this study was to identify genes encoding eggshell membrane proteins, particularly those responsible for its structural features, by analyzing the transcriptome of the white isthmus segment of the oviduct, which is the specialized region responsible for the fabrication of the membrane fibres.
RESULTS
The Del-Mar 14 K chicken microarray was used to investigate up-regulated expression of transcripts in the white isthmus (WI) compared with the adjacent magnum (Ma) and uterine (Ut) segments of the hen oviduct. Analysis revealed 135 clones hybridizing to over-expressed transcripts (WI/Ma + WI/Ut), and corresponding to 107 NCBI annotated non-redundant Gallus gallus gene IDs. This combined analysis revealed that the structural proteins highly over-expressed in the white isthmus include collagen X (COL10A1), fibrillin-1 (FBN1) and cysteine rich eggshell membrane protein (CREMP). These results validate previous proteomics studies which have identified collagen X (α-1) and CREMP in soluble eggshell extracts. Genes encoding collagen-processing enzymes such as lysyl oxidase homologs 1, 2 and 3 (LOXL1, LOXL2 and LOXL3), prolyl 4 hydroxylase subunit α-2 and beta polypeptide (P4HA2 and P4HB) as well as peptidyl-prolyl cis-trans isomerase C (PPIC) were also over-expressed. Additionally, genes encoding proteins known to regulate disulfide cross-linking, including sulfhydryl oxidase (QSOX1) and thioredoxin (TXN), were identified which suggests that coordinated up-regulation of genes in the white isthmus is associated with eggshell membrane fibre formation.
CONCLUSIONS
The present study has identified genes associated with the processing of collagen, other structural proteins, and disulfide-mediated cross-linking during eggshell membrane formation in the white isthmus. Identification of these genes will provide new insight into eggshell membrane structure and mechanisms of formation that will assist in the development of selection strategies to improve eggshell quality and food safety of the table egg.
Publication
Journal: Journal of environmental pathology, toxicology and oncology : official organ of the International Society for Environmental Toxicology and Cancer
May/23/2018
Abstract
Nickel (Ni) is an important environmental toxicant that can cause cancer and cardiovascular disease. The aim of this study was to examine the protective effects of troxerutin (Txn) Ni-induced renal dysfunction in rats using biochemical and histopathological approaches. Nickel (20 mg/kg body weight [b.w.]/day) was administered intraperitoneally (i.p.) for 20 days. Renal damage from Ni toxicity was evident from the changed levels of serum and urinary markers in Ni-treated rats. The levels of lipid peroxidation markers also significantly increased, while the levels of nonenzymatic and enzymatic antioxidants significantly decreased in the kidney of Ni-intoxicated rats. Troxerutin was administered orally (100 mg/kg b.w.) for 20 days along with Ni, resulting in a reversal of Ni-induced biochemical changes in kidney accompanied by a significant decrease in lipid peroxidation and an increase in the level of renal antioxidant defense system. Histopathological studies in the kidneys of rats also showed that troxerutin (100 mg/ kg b.w.) markedly reduced the toxicity of Ni and preserved the normal histological architecture of the renal tissue. The present study results suggest the nephroprotective potential of Txn in Ni toxicity, which might be due to its antioxidant and metal-chelating properties.
Publication
Journal: Journal of clinical medicine
August/24/2019
Abstract
The pathogenesis of glaucoma is strongly associated with the occurrence of autoimmune-mediated loss of retinal ganglion cells (RGCs) and additionally, recent evidence shows that specific antibody-derived signature peptides are significantly differentially expressed in sera of primary-open angle glaucoma patients (POAG) compared to healthy controls. Synthetically antibody-derived peptides can modulate various effector functions of the immune system and act as antimicrobial or antiviral molecules. In an ex vivo adolescent glaucoma model, this study, for the first time, demonstrates that polyclonal-derived complementarity-determining regions (CDRs) can significantly increase the survival rate of RGCs (p = 0.013). We subsequently performed affinity capture experiments that verified the mitochondrial serine protease HTRA2 (gene name: HTRA2) as a high-affinity retinal epitope target of CDR1 sequence motif ASGYTFTNYGLSWVR. Quantitative proteomic analysis of the CDR-treated retinal explants revealed increased expression of various anti-apoptotic and anti-oxidative proteins (e.g., VDAC2 and TXN) compared to untreated controls (p < 0.05) as well as decreased expression levels of cellular stress response markers (e.g., HSPE1 and HSP90AA1). Mitochondrial dysfunction, the protein ubiquitination pathway and oxidative phosphorylation were annotated as the most significantly affected signaling pathways and possibly can be traced back to the CDR-induced inhibition or modulation of the master regulator HTRA2. These findings emphasize the great potential of synthetic polyclonal-derived CDR peptides as therapeutic agents in future glaucoma therapy and provide an excellent basis for affinity-based biomarker discovery purposes.
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