Biomedical subjects

Jia Chen

Publications and source records attributed to Jia Chen.

At least 19 recordsLinked to original sources

PubMed2026

Network pharmacology-based prediction and experimental validation of the anti-hyperuricemic effects of oolong tea polyphenols.

OBJECTIVE: This study aimed to identify candidate therapeutic targets of oolong tea polyphenols (TP) against hyperuricemia (HUA) using network pharmacology and bioinformatics, and to validate the predicted molecular mechanism through in vivo experimentation. METHODS: Drug and disease targets were retrieved from public databases, and overlapping targets were identified by Venn diagram analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed on the shared targets, and a protein-protein interaction (PPI) network was constructed to identify hub genes. For in vivo validation, an HUA mouse model was established by 15 days of oral potassium oxonate (PO) administration. Model mice then received TP by gavage at low (0.5 g⋅kg-1⋅d-1), medium (1 g⋅kg-1⋅d-1), or high (2 g⋅kg-1⋅d-1) doses for an additional 15 days. Serum biochemical markers, histopathological changes, and pathway-related protein expression were assessed by enzyme-linked immunosorbent assay (ELISA), hematoxylin and eosin (HE) staining, and western blot analysis, respectively. RESULTS: Network pharmacology analysis identified 59 overlapping targets between TP and HUA; GO and KEGG enrichment analyses revealed that these targets were primarily associated with hormone metabolism and the PI3K-AKT signaling pathway. In the animal experiment, TP dose-dependently reduced serum uric acid (SUA) levels in hyperuricemic mice. At the molecular level, low and medium doses of TP suppressed phosphorylation of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), and mammalian target of rapamycin (mTOR), whereas the high dose paradoxically activated this pathway and concomitantly elevated interleukin-1β levels. These findings indicate that TP modulates uric acid metabolism through a non-monotonic, dose-dependent mechanism. CONCLUSION: By combining network pharmacology with animal experiments, this study identified the PI3K/AKT/mTOR signaling pathway as a likely mediator of the anti-hyperuricemic action of oolong tea polyphenols (TP). A medium dose of TP achieved the most balanced outcome, attenuating inflammation and preserving hepatic and renal architecture; the high dose, by contrast, paradoxically elevated interleukin-1β (IL-1β) and overactivated PI3K/AKT/mTOR signaling, underscoring the importance of dose calibration. These data suggest that a medium dose of TP may represent a feasible dietary strategy against hyperuricemia. Further work-including monomer identification, direct target validation, and clinical evaluation-is warranted to confirm and extend these preclinical findings.

PI3K/Akt/mTOR signaling pathway↗

PubMed2026

Immune cell-specific genetic architecture of Alzheimer's disease revealed by multi-omics analysis for therapeutic target discovery and prioritization.

Alzheimer's disease (AD) is a multifactorial neurodegenerative condition in which accumulating genetic and molecular evidence implicates dysregulation of peripheral immune processes in disease pathogenesis. Nevertheless, the contribution of distinct peripheral immune cell subsets and associated gene regulatory landscapes to AD risk remains incompletely defined. To address this gap, we integrated single-cell expression quantitative trait loci (sc‑eQTL) data from the OneK1K cohort with AD GWAS summary statistics. We systematically interrogated immune cell-specific genes for their contributions to AD risk by integrating genetic causal inference with Bayesian colocalization analyses, and identified 24 eGenes that passed both the MR significance threshold (P < 0.05) and the criterion for strong shared genetic signals (PP.H4 > 0.8). Notable candidates included GATS, HLA-DOB, HLA-DQA1, PM20D1, and others, with each gene demonstrating a cell-type-specific association restricted to its corresponding immune cell type, such as monocytes, CD8 + T cells, or B cells. Independent peripheral blood single-cell transcriptomic data further supported disease-associated shifts in cell-type-specific expression patterns in AD. Phenome-wide association studies (PheWAS) indicated limited associations with off-target traits, indicating a favorable safety profile for therapeutic intervention, with the exceptions of B4GALNT3, PM20D1, and CNN2. Integration of immune gene targets with pharmacological databases yielded three candidate compound, including NSC321521 (targeting HLA-DQA1), phenoxybenzamine (targeting GSTP1), and rimexolone (targeting BIN1). Among these compounds, Predicted blood-brain barrier permeability was observed only for phenoxybenzamine and rimexolone, with docking studies indicating stable interactions, such as those between NSC321521 and HLA-DQA1, phenoxybenzamine and GSTP1, and rimexolone and BIN1. This integrative approach highlights key immune‑cell‑specific genes involved in AD and proposes repurposable drugs with central nervous system potential, paving the way for more targeted immunomodulatory strategies in AD.

Humans↗

PubMed2026

Eugenol-Derived Cytoprotective Action Against Dityrosine-Induced Oxidative Stress in Mice Liver via Akt/Nrf2/ARE Signaling Pathway.

Dityrosine (Dityr), a byproduct of protein oxidation in protein-rich food, induces oxidative stress, inflammation, and apoptosis, jeopardizing human health. Eugenol (EUG), a natural compound with antioxidative and anti-inflammatory properties, was investigated for its protective effects against Dityr-induced hepatotoxicity in this work. In this study, in vivo and in vitro analyses demonstrated EUG's protective effects against Dityr-induced hepatotoxicity. EUG significantly attenuated oxidative stress markers, inflammatory infiltration, fibrotic progression, and apoptotic signaling in mice liver tissues. Mechanistically, EUG activated the Akt/NF-E2-related factor 2/antioxidant response element (Akt/Nrf2/ARE) pathway, enhancing cellular antioxidant capacity while suppressing pro-inflammatory cytokine release. In HepG2 cells, EUG treatment effectively counteracted Dityr-induced ROS overproduction and cell death through Nrf2-mediated antioxidant upregulation. In conclusion, our findings indicate that EUG effectively mitigates Dityr-induced oxidative stress via the Akt/Nrf2/ARE pathway, and this antioxidative impact further inhibits inflammation and apoptosis. These effects ultimately ameliorate liver function impairment caused by Dityr.

Animals↗

PubMed2025

Causal relationship between albumin, total protein, and colorectal cancer risk: A 2-sample Mendelian randomization study.

Albumin (ALB) and total protein (TP) are vital constituents of the blood, and their levels and roles in the risk of colorectal cancer (CRC) are of significance. Previous observational studies have reported correlations among ALB, TP, and CRC. However, the existence of a causal relationship between ALB and CRC in European populations has not been adequately investigated and the causal link between TP and CRC remains unexplored. To address these gaps, we applied Mendelian randomization (MR) to investigate the potential causal relationship between ALB, TP, and CRC. Two-sample MR analysis was used to investigate whether there was a causal relationship between ALB, TP, and CRC. Our exposure data were extracted from genome-wide association study (GWAS) databases sourced from the UK Biobank, containing 315,268 and 314,921 Europeans participants for ALB and TP analyses, respectively. Single nucleotide polymorphisms that were significantly associated with ALB and TP were assessed using GWAS datasets. Our data were derived from the FinnGen Consortium CRC GWAS, which contained 6509 CRC cases and 28,7137 controls. Causal inference between ALB, TP, and CRC was performed using 3 MR methods: inverse variance weighting (IVW), MR-Egger, and weighted median. The IVW analysis showed no significant causal association between ALB and CRC (OR = 1.04, 95% CI = 0.89-1.21, P = .65). In contrast, the IVW analysis for TP and CRC showed a significant causal association (OR = 0.78, 95% CI = 0.66-0.92, P = .003), suggesting a reduced risk of CRC. Through a 2-sample MR study investigating the causal relationship between ALB, TP, and CRC in a European population, our findings revealed a significant causal relationship between TP and a reduced risk of CRC.

Humans↗

PubMed2025

Prenatal pyrethroid exposure, placental gene network modules, and neonatal neurobehavior.

Prenatal pesticide exposure may adversely affect child neurodevelopment which may partly arise from impairing the placenta's vital role in fetal development. In a cohort of pregnant farmworkers from Thailand (N = 248), we examined the links between urinary metabolites of pyrethroid pesticides during pregnancy, placental gene expression networks derived from transcriptome sequencing, and newborn neurobehavior assessed using the NICU Network Neurobehavioral Scales (NNNS) at 5 weeks of age. Focusing on the 21 gene network modules in the placenta identified by Weighted Gene Co-expression Network Analysis, our analysis revealed significant associations between metabolites and nine distinct modules, and between thirteen modules and NNNS, with eight modules showing overlap. Notably, stress was negatively associated with the interferon alpha response and Myc target modules, and the interferon alpha response module was correlated positively with attention, and negatively with arousal, and quality of movement. The analysis also highlighted the early and late trimesters as critical periods for the exposures influence on placental function, with pyrethroid metabolites measured early in pregnancy significantly negatively associated with the protein secretion module, and those measured later in pregnancy negatively associated with modules related to oxidative phosphorylation (OXPHOS) and DNA repair. Additionally, the cumulative sum of 3-phenoxybenzoic acid across pregnancy was significantly negatively associated with the OXPHOS module. These findings suggest that prenatal exposure to pyrethroids may influence neonatal neurobehavior through specific placental mechanisms that impact gene expression of metabolic pathways, and these effects may be pregnancy period specific. These results offer valuable insights for future risk assessment and intervention strategies.

Prenatal Exposure Delayed Effects↗

PubMed2025

A quick guide to evaluating prime editing efficiency in mammalian cells.

According to the Clinvar database, modeling the diseases associated with pathogenic mutations requires the installation of base substitutions, small insertions or deletions. Prime editor (PE) was recently developed to precisely install any base substitutions and/or small insertions/deletions (indels) in mammalian cells and animals without requiring DSBs or donor DNA templates. PE also offers greater editing and targeting flexibility compared to other precision CRISPR editing methods because the versatile editing information is encoded in the reverse-transcription template of its prime editing guide RNA. However, optimal PE system selection and experimental design can be complex, and there are various factors that can affect PE efficiency. This chapter serves as a rapid entry-level guideline for the application of PE, providing an experimental framework for using PE at a specific genomic locus. RUNX1 was selected as a representative target site to illustrate the detailed methodology for constructing PE plasmids and the process of transfecting these plasmids into 293FT cells. We further examined the efficiency of PE-mediated genome editing in mammalian cells by using next-generation sequencing.

Gene Editing↗

PubMed2007

Regulation of leukocyte degranulation by cGMP-dependent protein kinase and phosphoinositide 3-kinase: potential roles in phosphorylation of target membrane SNARE complex proteins in rat mast cells.

We examined the roles of cGMP-dependent protein kinase (PKG) and PI3K in degranulation induced by fMLF and by FcepsilonRI cross-linking. In rat basophilic leukemia-2H3 cells expressing formyl peptide receptor, the PKG inhibitors KT5823 and Rp-8-Br-PET-cGMP, as well as the PI3K inhibitor LY294002, reduced agonist-stimulated beta-hexosaminidase release in a dose-dependent manner. These inhibitors also abolished vesicular fusion with the plasma membrane, as evidenced by diminished annexin V staining. Agonist-induced degranulation was completely blocked when LY294002 was applied together with one of the PKG inhibitors, suggesting an additive and possibly synergistic effect. In contrast, the PKG inhibitors did not affect fMLF-induced intracellular calcium mobilization and Akt phosphorylation. Likewise, LY294002 did not alter fMLF-induced elevation of intracellular cGMP concentration, and the inhibitory effect of LY294002 was not reversed by a cell-permeable analog of cGMP. Treatment with fMLF induced phosphorylation of soluble N-ethylmaleimide-sensitive factor-attachment protein (SNAP)-23, syntaxins 2, 4, and 6, and Monc18-3. The induced phosphorylation of SNAP-23 and syntaxins 2 and 4 was blocked by Rp-8-Br-PET-cGMP and LY294002. However, LY294002 was less effective in inhibiting Munc18-3 phosphorylation. The induced phosphorylation of syntaxin 6 was not effectively blocked by either Rp-8-Br-PET-cGMP or LY294002. Treatment of human neutrophils with the PKG inhibitors and LY294002 reduced enzyme release from primary, secondary, and tertiary granules. These results suggest that PKG and PI3K are involved in degranulation, possibly through phosphorylation of target membrane SNAP receptor proteins and their binding proteins.

Animals↗

PubMed2006

Transcriptional activator TSRF1 reversely regulates pathogen resistance and osmotic stress tolerance in tobacco.

Increasing evidences show that ethylene-responsive factor (ERF) proteins regulate plant stress response and the interaction of different stress responsive pathways through interacting with different cis-acting elements, even other transcription factors. Here, we report a transcriptional activator TSRF1, which was previously demonstrated to regulate plant resistance to Ralstonia solanacearum, reversely regulates pathogen resistance and osmotic stress tolerance in tobacco. Sequence analysis revealed that TSRF1 contains a putative transcriptional activation domain. Using yeast two hybrid system we evidenced that this activation domain is essential for activating the expression of reporter gene. To confirm the broad-spectrum pathogen resistance of TSRF1 we observed that over-expressing TSRF1 enhances the resistance to Pseudomonas syringae and Botrytis cinerea in both tobacco and tomato plants, but RNA interference of TSRF1 in tomato plants decreases the resistance to these pathogens, unraveling the positive regulation of TSRF1 in plant pathogen infections. The expression of TSRF1 in response to NaCl and mannitol suggests the possible functions of TSRF1 in osmotic stress responses, but the physiological tests indicate that expressing TSRF1 in tobaccos decreases tolerance to NaCl or mannitol during germination and seedling root development, and this result was consistent with PEG6000 treatment with mature tobacco seedlings, indicating the negative modulation of TSRF1 in osmotic stress response. Therefore, our research reveals that transcriptional activator TSRF1 reversely regulates plant pathogen resistance and osmotic stress response.

Amino Acid Sequence↗

PubMed2006

A novel drought-inducible gene, ATAF1, encodes a NAC family protein that negatively regulates the expression of stress-responsive genes in Arabidopsis.

NAC proteins are plant-specific transcriptional regulators. ATAF1 was one of the first identified NAC proteins in Arabidopsis. In present study, we characterized the ATAF1 expression and biological function in response to water deficit stress. ATAF1 mRNA expression was strongly induced by dehydration and abscisic acid (ABA) treatment, but inhibited by water treatment, suggesting a general role in drought stress responses. Transient expression analysis in onion epidermal cells indicated the nuclear localization for the ATAF1::GFP fusion protein. Yeast transactivation analysis showed that ATAF1 had ability to activate reporter gene expression. Furthermore, domain deletion analysis revealed that the ATAF1 transactivation activity was conferred by its C-terminal domain. When ATAF1 gene was knocked out by T-DNA insertions, Arabidopsis ataf1-1 and ataf1-2 mutants displayed a recovery rate about seven times higher than wild-type plants in drought response test. This ataf1 phenotype was coincident with the enhanced expression of stress responsive marker genes, such as COR47, ERD10, KIN1, RD22 and RD29A under drought stress. Above evidences suggest that ATAF1, as a transcriptional regulator, negatively regulates the expression of stress responsive genes under drought stress in Arabidopsis.

Arabidopsis↗

PubMed2006

Zinc finger protein 1 (ThZF1) from salt cress (Thellungiella halophila) is a Cys-2/His-2-type transcription factor involved in drought and salt stress.

Zinc finger proteins (ZFPs) play important roles in growth and development in both animals and plants. Recently, some Arabidopsis genes encoding distinct ZFPs have been identified. However, the physiological role of their homologues with putative zinc finger motif remains unclear. In the present study, a novel gene, ThZF1, was characterized from salt stressed cress (Thellungiella halophila, Shan Dong), encoding a functional transcription factor. ThZF1 contains two conserved C(2)H(2) regions and shares conserved domains, including DNA-binding motif, with Arabidopsis thaliana ZFP family members. The transcript of the ThZF1 gene was induced by salinity and drought. Transient expression analysis of ThZF1-GFP fusion protein revealed that ThZF1 was localized preferentially in nucleus. A gel-shift assay showed that ThZF1 specially bind to the wild-type (WT) EP2 element, a cis-element present in the promoter regions of several target genes regulated by ZFPs. Furthermore, a functional analysis demonstrated that ThZF1 was able to activate HIS marker gene in yeast. Finally, ectopic expression of ThZF1 in Arabidopsis mutant azf2 suggested that ThZF1 may have similar roles as Arabidopsis AZF2 in plant development as well as regulation of downstream gene.

Amino Acid Sequence↗

PubMed2006

An Arabidopsis glutathione peroxidase functions as both a redox transducer and a scavenger in abscisic acid and drought stress responses.

We isolated two T-DNA insertion mutants of Arabidopsis thaliana GLUTATHIONE PEROXIDASE3 (ATGPX3) that exhibited a higher rate of water loss under drought stress, higher sensitivity to H(2)O(2) treatment during seed germination and seedling development, and enhanced production of H(2)O(2) in guard cells. By contrast, lines engineered to overexpress ATGPX3 were less sensitive to drought stress than the wild type and displayed less transpirational water loss, which resulted in higher leaf surface temperature. The atgpx3 mutation also disrupted abscisic acid (ABA) activation of calcium channels and the expression of ABA- and stress-responsive genes. ATGPX3 physically interacted with the 2C-type protein phosphatase ABA INSENSITIVE2 (ABI2) and, to a lesser extent, with ABI1. In addition, the redox states of both ATGPX3 and ABI2 were found to be regulated by H(2)O(2). The phosphatase activity of ABI2, measured in vitro, was reduced approximately fivefold by the addition of oxidized ATGPX3. The reduced form of ABI2 was converted to the oxidized form by the addition of oxidized ATGPX3 in vitro, which might mediate ABA and oxidative signaling. These results suggest that ATGPX3 might play dual and distinctive roles in H(2)O(2) homeostasis, acting as a general scavenger and specifically relaying the H(2)O(2) signal as an oxidative signal transducer in ABA and drought stress signaling.

Abscisic Acid↗

PubMed2006

Serum amyloid A is an endogenous ligand that differentially induces IL-12 and IL-23.

The acute-phase proteins, C-reactive protein and serum amyloid A (SAA), are biomarkers of infection and inflammation. However, their precise role in immunity and inflammation remains undefined. We report in this study a novel property of SAA in the differential induction of Th1-type immunomodulatory cytokines IL-12 and IL-23. In peripheral blood monocytes and the THP-1 monocytic cell line, SAA induces the expression of IL-12p40, a subunit shared by IL-12 and IL-23. SAA-stimulated expression of IL-12p40 was rapid (< or = 4 h), sustainable (> or = 20 h), potent (up to 3380 pg/ml/10(6) cells in 24 h), and insensitive to polymyxin B treatment. The SAA-stimulated IL-12p40 secretion required de novo protein synthesis and was accompanied by activation of the transcription factors NF-kappaB and C/EBP. Expression of IL-12p40 required activation of the p38 MAPK and PI3K. Interestingly, the SAA-induced IL-12p40 production was accompanied by a sustained expression of IL-23p19, but not IL-12p35, resulting in preferential secretion of IL-23, but not IL-12. These results identify SAA as an endogenous ligand that potentially activates the IL-23/IL-17 pathway and present a novel mechanism for regulation of inflammation and immunity by an acute-phase protein.

Cell Line, Tumor↗

PubMed2006

Using a modified TA cloning method to create entry clones.

We describe a noncommercial alternative method to create entry clones compatible with all kinds of destination vectors based on an improved TA cloning approach. To generate Gateway T vectors, we first constructed gentamicin- and chloramphenicol-resistant entry vectors designated pGWG and pGWC, respectively. Each entry vector contains an AhdI cassette flanked by attL sites, with each AhdI cassette containing two AhdI restriction enzyme sites spaced by the ccdB killer gene, which is lethal to most Escherichia coli strains. Gateway T vectors can be prepared by simple digestion of these entry vectors with the AhdI enzyme or its isoschizomers. The use of the ccdB gene as a negative selection marker is an important improvement over conventional TA cloning in that it eliminates the necessity of blue/white color screening based on alpha-complementation. Another important improvement that we have implemented is to retail the T vectors using Taq polymerase and dTTP so as to improve the cloning efficiency. Together, these improvements allow TA cloning to realize its full potential. Using Gateway T vectors prepared by this improved method, entry clones for PCR products or restriction enzyme fragments can be created simply, efficiently, and inexpensively while at the same time introducing greater compatibility.

Chloramphenicol↗

PubMed2006

A Gateway-based platform for multigene plant transformation.

The post-genomic era offers unrivalled opportunities for genetic manipulation of polygenic traits, multiple traits, and multiple gene products. However, remaining technical hurdles make the manipulation of multiple genes in plants difficult. Here we describe a Gateway-based vector system to enable multiple transgenes to be directly linked or fused. The vector system consists of a destination vector and two special attL-flanked entry vectors each containing an attR cassette incompatible with the attL. By multiple rounds of LR recombination reactions, which we call MultiRound Gateway, multiple transgenes can be delivered sequentially and indefinitely into the Gateway-compatible destination vector through alternate use of the two special entry vectors. In our proof-of-principle experiments we have used this vector system to construct a plant transformation vector containing seven functional DNA fragments, including a screening marker gene, two reporter genes and four matrix attachment region sequences. This system provides a platform for fully realizing the potential of plant genetic manipulation.

Arabidopsis↗

PubMed2006

NADK3, a novel cytoplasmic source of NADPH, is required under conditions of oxidative stress and modulates abscisic acid responses in Arabidopsis.

In plants, excess reactive oxygen species are toxic molecules induced under environmental stresses, including pathogen invasions and abiotic stresses. Many anti-oxidant defense systems have been reported to require NADPH as an important reducing energy equivalent. However, the sources of NADPH and the molecular mechanisms of maintaining cytoplasmic redox balance are unclear. Here, we report the biological function of a putative cytoplasmic NADH kinase (NADK3) in several abiotic stress responses in Arabidopsis. We found that cytoplasmic NADPH is provided mostly by the product of the NADK3 gene in Arabidopsis. Expression of he NADK3 gene is responsive to abscisic acid (ABA) and abiotic stress conditions, including methyl violgen (MV), high salinity and osmotic shock. An NADK3 null mutant showed hypersensitivity to oxidative stress in both seed germination and seedling growth. Seed germination of the mutant plants also showed increased sensitivity to ABA, salt and mannitol. Furthermore, stress-related target genes were identified as upregulated in the mutant by mannitol and MV. Our study indicates that this cytoplasmic NADH kinase, a key source of the cellular reductant NADPH, is required for various abiotic stress responses.

Abscisic Acid↗

PubMed2006

Comparison of statistical models for analyzing genotype, inferred haplotype, and molecular haplotype data.

This report compares statistical models based on molecular and inferred haplotypes of the human paraoxonase-1 gene (PON1). In a study of 402 women comprising three race/ethnicities, 137 women had ambiguous inferred haplotypes. The inferred haplotypes (the one with highest posterior probability) for 20 of these women differed from molecular haplotypes, while based on the posterior distribution from the imputation method, 30 discrepancies were expected. We examined the proportion of the variance in PON1 enzymatic activity (phenotype) explained by genotype, and by inferred and molecular haplotype information. For Caucasians, there was an improvement in adjusted R(2) from 16% for the genotype count model, to 29% for imputed haplotypes, and a further improvement to 33% for molecular haplotypes. For Hispanics and African-Americans, there was no indication that haplotypes helped in explaining PON1 activity, and the imputed model gave essentially the same R(2) as the molecular model. For African-Americans, none of the models had adjusted R(2) that exceeded 4%, while for Hispanics they were all about 21-22%. We propose a new parsimonious model which uses all the genotype information and selected haplotype information. For PON1, this model achieves essentially the same adjusted R(2) as the all-haplotype model, with a potential cost savings and without giving the extreme predictions for uncommon haplotype combinations that the all-haplotype models provides.

Aryldialkylphosphatase↗

PubMed2006

Construction of single chain variable fragment (ScFv) and BiscFv-alkaline phosphatase fusion protein for detection of Bacillus anthracis.

This paper describes an attempt for convenient and sensitive detection of Bacillus anthracis with single chain variable fragment (scFv)-based protein chip. Phage display technology was employed to generate scFv by using the protective antigen (PA) of B. anthracis for immunization. V(H) and V(L) genes of the scFv were amplified separately by reverse transcriptase-PCR from mRNA of immunized mice and then assembled into scFv gene with a linker DNA sequence. The scFv gene was inserted into a phagemid vector pCANTAB-5E and then transformed into Escherichia coli TG1 to yield recombinant phages after infection with helper phage M13KO7. After six rounds of panning with PA, the phage clones displaying scFv fragments of the antibody were selected by ELISA. One phage clone scFv-6w10 showing the strongest positive signal in ELISA was selected. To enhance the affinity of the scFv-6w10, a recombinant bivalent single-chain Fv antibody (biscFv-6w10) directed against PA was constructed and tested in functional assays. The affinity of the biscFv-6w10 was much higher than that of scFv-6w10 and reached 6.5 x 10(9) M(-1). An expression system was constructed for the production of E. coli alkaline phosphatase (EAP) labeled biscFv-6w10 (biscFv-6w10-EAP) in E. coli cells. The expressed fusion protein retained both antigen-specific binding and enzymatic activity and thus directly served as an enzyme-labeled antibody. Detections of PA and bacterial cells of B. anthracis using biscFv-6w10-EAP and Cy3-labeled biscFv-6w10 were performed on a protein chip. The fusion protein (biscFv-6w10-EAP) chip could detect 10 pg of PA and 500-1000 bacterial cells in approximately 2 h, while the sensitivity of Cy3-labeled protein chip reached 1 pg of PA and 50-100 cells within 2 h.

Alkaline Phosphatase↗

PubMed2006

Gastric cancer risk in a Mexican population: role of Helicobacter pylori CagA positive infection and polymorphisms in interleukin-1 and -10 genes.

Several polymorphisms of the IL1B and IL10 gene promoters have been reported to be associated with gastric cancer risk in Caucasians. However, studies in other populations have shown differing results. We aimed to test for associations between polymorphisms in IL1B (-31 and +3954), IL10-592 and IL1RN variable number of tandem repeats (VNTR) and risk of gastric cancer in a Mexican population. DNA was extracted from sera of 183 gastric adenocarcinoma patients and 377 controls. The IL1B-31, IL1B+3954 and IL10-592 biallelic polymorphisms were discriminated using 5' Nuclease (TaqMan) assays and Pyrosequencing. The IL1RN penta-allelic VNTR polymorphism was genotyped using PCR followed by GeneScan analysis. A significant interaction was found between IL1B-31 and CagA status for the risk of intestinal-type gastric cancer (p = 0.023). Among CagA positive subjects, those with IL1B-31CC genotype had an increased risk of intestinal-type gastric cancer (OR 3.19, 95%CI = 1.05-9.68), compared to carriers of IL1B-31TT genotype. In contrast, among CagA negative subjects, no significant association of IL1B-31CC genotype with gastric cancer was observed. The IL10-592CC genotype was associated with more than doubling of the risk of the intestinal-type gastric cancer (OR, 2.20, 95%CI = 1.04-4.65). A nonsignificantly increased risk for intestinal-type gastric cancer was found in IL1RN*2 carriers (OR 1.49, 95%CI = 0.89-2.50). None of these polymorphisms was significantly related to the risk of diffuse-type gastric cancer. No significant association was found between risk of gastric cancer and the IL1B+3954 polymorphism. Individuals carrying 2 or more of the risk-associated alleles (IL1B-31C, IL1RN *2 and IL10-592C) were at increased risk for intestinal-type gastric cancer, compared to those with 0 or 1 risk-associated allele. The risk from multiple risk-associated alleles was especially high in subjects infected with CagA positive H. pylori. Our results support the identification of the IL1B-31 promoter polymorphism as a useful marker for risk of intestinal type gastric cancer in persons with CagA positive H. pylori infections.

Adenocarcinoma↗