Biomedical subjects

Chunxia Zhao

Publications and source records attributed to Chunxia Zhao.

16 recordsLinked to original sources

PubMed2026

Proteomic and metabolomic profiling reveals dysregulation of immune states, mucin-type glycosylation and steroid metabolism in extramammary Paget's disease.

BACKGROUND: Extramammary Paget's disease is a rare cutaneous adenocarcinoma characterized by mucin-rich Paget cells and chronic inflammation, yet its molecular basis remains unclear. OBJECTIVE: To systematically characterize the proteomic and metabolomic landscape of EMPD, uncover immune heterogeneity, and identify molecular pathways underlying tumor progression and microenvironment remodeling. METHODS: We performed integrated proteomic and metabolomic analyses on 92 male tumor patients and 30 healthy controls, identifying 10,217 proteins and 1466 metabolites. RESULTS: Extramammary Paget's disease lesions exhibited broad activation of inflammatory pathways. Immune profiling further uncovered substantial inflammatory heterogeneity, delineating immune-cold and immune-hot subtypes, with the latter associated with stronger invasive potential. Aberrant mucin-type glycosylation was also prominent, featuring Tn-modified MUC1 and MUC5AC accompanied by elevated GALNT7, GALNT6, GALNT4, and ST6GAL1, which correlated with inflammatory intensity. Metabolomic data demonstrated elevated levels of testosterone, dehydroepiandrosterone, and related intermediates in tumor tissues, indicating an androgen-enriched metabolic profile in extramammary Paget's disease. CONCLUSION: These findings reveal immune, glycoproteomic, and metabolomic pathways in extramammary Paget's disease pathogenesis and provide novel insights for molecular classification and therapeutic targeting.

Humans↗

PubMed2006

Structure and properties of regenerated Antheraea pernyi silk fibroin in aqueous solution.

Antheraea pernyi silk fibroin fibers were dissolved by aqueous lithium thiocyanate to obtain regenerated A. pernyi silk fibroin solution. By means of circular dichroism, (13)C NMR and Raman spectroscopy, the molecular conformation of regenerated A. pernyi silk fibroin in aqueous solution was investigated. The relationship of environmental factors and sol-gel transformation behavior of regenerated A. pernyi silk fibroin was also studied. The molecular conformations of regenerated A. pernyi silk fibroin mainly were alpha-helix and random coil in solution. There also existed a little beta-sheet conformation. It was obviously different with Bombyx mori silk fibroin, whose molecular conformation in solution was only random coil but no alpha-helix existence. With the increase of temperature and solution concentration and with the decrease of solution pH value, the gelation velocity of regenerated A. pernyi silk fibroin solution increased. Especially, it showed that A. pernyi silk fibroin was more sensitive to temperature than B. mori silk fibroin during the sol-gel transformation. The velocity increased obviously when the temperature was above 30 degrees C. During the sol-gel transformation, the molecular conformation of regenerated A. pernyi silk fibroin changed from random coil to beta-sheet structure. The results of these studies provided important insight into the preparation of new biomaterials by silk fibroin protein.

Animals↗

PubMed2006

Endobrevin/VAMP-8 is the primary v-SNARE for the platelet release reaction.

Platelet secretion is critical to hemostasis. Release of granular cargo is mediated by soluble NSF attachment protein receptors (SNAREs), but despite consensus on t-SNAREs usage, it is unclear which Vesicle Associated Membrane Protein (VAMPs: synaptobrevin/VAMP-2, cellubrevin/VAMP-3, TI-VAMP/VAMP-7, and endobrevin/VAMP-8) is required. We demonstrate that VAMP-8 is required for release from dense core granules, alpha granules, and lysosomes. Platelets from VAMP-8-/- mice have a significant defect in agonist-induced secretion, though signaling, morphology, and cargo levels appear normal. In contrast, VAMP-2+/-, VAMP-3-/-, and VAMP-2+/-/VAMP-3-/- platelets showed no defect. Consistently, tetanus toxin had no effect on secretion from permeabilized mouse VAMP-3-/- platelets or human platelets, despite cleavage of VAMP-2 and/or -3. Tetanus toxin does block the residual release from permeabilized VAMP-8-/- platelets, suggesting a secondary role for VAMP-2 and/or -3. These data imply a ranked redundancy of v-SNARE usage in platelets and suggest that VAMP-8-/- mice will be a useful in vivo model to study platelet exocytosis in hemostasis and vascular inflammation.

Adenosine Triphosphate↗

PubMed2006

Strong and selective binding of amiloride to thymine base opposite AP sites in DNA duplexes: simultaneous binding to DNA phosphate backbone.

Amiloride (N-amidino-3,5-diamino-6-chloro-pyrazinecarboxamide hydrochloride) has two sets of hydrogen-bond forming sites suitable for target nucleotides and the phosphodiester DNA backbone by which a thymine base opposite an abasic site in DNA duplexes can be recognized with high selectivity and affinity, and it is applicable to the fluorescence detection of thymidine-related SNPs (single-nucleotide polymorphisms) of PCR amplification products.

Amiloride↗

PubMed2006

Methylation analysis of hMLH1 gene promoter by a bisulfite-sensitive single-strand conformation polymorphism-capillary electrophoresis method.

DNA methylation is an important epigenetic modification that alters transcription in those genes containing CpG islands. In this report, a novel DNA methylation analysis method was developed employing bisulfite-single strand conformation polymorphism combined with capillary electrophoresis (bisulfite-SSCP-CE). During the bisulfite treatment of genomic DNA, a high concentration of sodium bisulfite (4.8 mol/L) was preferred in order to shorten reaction time and minimize template degradation. The methylated and unmethylated ssDNA of hMLH1 promoter were simultaneously separated under the optimized CE conditions, including 6% SLPA with 10% glycerol as sieving medium, 25 degrees C as separation temperature and 12 kV as running voltage. The heterogeneous methylation of hMLH1 promoter was identified in 13 of 64 colorectal cancer patients. Moreover, hMLH1 promoter methylation had a significant relationship with protein expression loss and increased with the age of patients. Our results indicated that DNA methylation analysis for a large number of clinical samples would be facilitated by use of the bisulfite-SSCP-CE method.

Adaptor Proteins, Signal Transducing↗

PubMed2006

Preparative isolation and purification of atractylon and atractylenolide III from the Chinese medicinal plant atractylodes macrocephala by high-speed counter-current chromatography.

The medicinal plant Atractylodes macrocephala (Baizhu in Chinese) has been widely used in traditional Chinese medicine for energy and stomach complaints, treatment of dyspepsia and anorexia, anti-inflammation, anticancer and for increasing assimilation. A high-speed counter-current chromatography (HSCCC) method was developed for the preparative separation and purification of two main bioactive components, namely, atractylon and atractylenolide III from A. macrocephala by using light petroleum (60-90 degrees C)-ethyl acetate-ethanol-water (4:1:4:1 v/v) as the two-phase solvent system in dual-mode elution. Compared with the separation using the normal-mode elution, the dual-mode HSCCC can be achieved with shorter elution time. Atractylenolide III (32.1 mg) at 99.0% purity and 319.6 mg atractylon at 97.8% purity could be obtained from 1000 mg crude sample in a single run. The recoveries of atractylenolide III and atractylon were 95.4 and 92.6%, respectively.

Journal Article↗

PubMed2005

Effects of bezafibrate on the expression of endothelial nitric oxide synthase gene and its mechanisms in cultured bovine endothelial cells.

OBJECTIVE: Peroxisome proliferator-activated receptors alpha (PPARalpha) is a target gene for atherosclerosis and cardiovascular diseases. However, effects of PPARalpha on endothelial nitric oxide synthase (eNOS) remain unknown. We investigated the eNOS regulation by bezafibrate, a ligand of PPARalpha, and involved signaling pathways. METHODS AND RESULTS: Firstly, in cultured bovine aorta endothelial cells (BAEC), bezafibrate significantly upregulated eNOS at protein, mRNA levels and NO production, respectively, in a concentration-dependent fashion (50-200muM). Next, the effects of bezafibrate on signal pathways and eNOS mRNA stability in BAEC were investigated. Results showed that bezafibrate induced phosphorylation of MAPK. Inhibitors of PPARalpha, PI3 kinase and MAPK, respectively, markedly attenuate bezafibrate-induced upregulation of eNOS. Bezafibrate incubation increased eNOS mRNA half-life, activated eNOS promoter, enhanced phosphorylation of eNOS ser-1179 site, and decreased phosphorylation of eNOS thr-497 site via activating ERK and Akt. CONCLUSIONS: Bezafibrate can upregulate eNOS expression, enhance phosphorylation of eNOS ser-1179, increase NO production and transcription level and stability of eNOS mRNA through pathway dependent of PPARalpha and nongenomic effects mediated by MAPK and PI3K pathways. Hence, PPARalpha ligands exert direct benefits on vessel endothelial functions through an increase in eNOS expression level and phosphorylation of eNOS ser-1179. This mechanism provides additional anti-atherosclerotic and anti-hypertension benefits of bezafibrate in addition of lipid-lowering effects.

Animals↗

PubMed2005

Rapid identification of pathogenic bacteria by capillary electrophoretic analysis of rRNA genes.

Molecular diagnosis is playing an increasingly important role in the rapid detection and identification of pathogenic organisms in clinical samples. The genetic variation of ribosomal genes in bacteria offers an alternative to culturing for the detection and identification of these organisms. Here 16S rRNA and 16S-23S rRNA spacer region genes were chosen as the amplified targets for single-strand conformation polymorphism (SSCP) and restriction fragment length polymorphism (RFLP) capillary electrophoresis analysis and bacterial identification. The multiple fluorescence based SSCP method for the 16S rRNA gene and the RFLP method for the 16S-23S rRNA spacer region gene were developed and applied to the identification of pathogenic bacteria in clinical samples, in which home-made short-chained linear polyacrylamide (LPA) was used as a sieving matrix; a higher sieving capability and shorter analysis time were achieved than with a commercial sieving matrix because of the simplified template preparation procedure. A set of 270 pathogenic bacteria representing 34 species in 14 genera were analyzed, and a total of 34 unique SSCP patterns representing 34 different pathogenic bacterial species were determined. Based on the use of machine code to represent peak patterns developed in this paper, the identification of bacterial species becomes much easier.

Bacteria↗

PubMed2005

Adrenomedullin gene delivery alleviates hypertension and its secondary injuries of cardiovascular system.

Adrenomedullin (AM) is a hypotensive peptide that functions as an important regulator in the cardiovascular and renal systems. The current study explored the potential therapeutic effects of delivering the human AM cDNA via a novel double-stranded adeno-associated virus vector (dsAAV) on hypertension and related complications in spontaneously hypertensive rats (SHR). A single dose of dsAAV-AM vector administered by tail vein injection into adult SHR resulted in significant reduction of systolic blood pressure at 2 weeks after gene delivery. This effect was observed through the entire duration of the experiment period (up to 16 weeks). Administration of dsAAV-AM also resulted in a decrease in total urine microalbumin content. Left ventricle and cardiomyocyte hypertrophy, fibrosis in the heart, glomerular sclerosis, and tubular injuries in the kidney were significantly reduced. Moreover, deterioration of hemodynamic variables was prevented in treated rats, as compared with the control groups. We conclude that AAV-mediated AM delivery can render a longterm and stable reduction of hypertension and protect against renal injury and cardiac remodeling in the spontaneously hypertensive rat model. Further preclinical studies are warranted for the development of a gene therapy strategy for human hypertension.

Adenoviridae↗

PubMed2005

Fluorescence detection of thymidine-related single-nucleotide polymorphisms by 3, 5-diaminopyrazine derivatives.

We report on a highly selective fluorescence ligand for thymine (T) base opposite an abasic site (AP site) in DNA duplexes. From the examination of the binding behaviors in solutions buffered to pH 7.0, we find that 6-chloro-3,5-diamino-2-pyrazinecarbonitrile (CDPC) can selectively recognize T with high affinity (Ka = 2.9 x 10(5) M(-1)), and the fluorescence intensity at 424 nm is significantly quenched only when binding to T. It is highly likely that the selective interaction of CDPC with T is explained by a pseudo-base pairing, for which three point hydrogen bonds are formed along the Watson-Crick edge of the target T. These binding functions of CDPC at the AP site are presented to develop ligand-based fluorescence assay for SNPs (single-nucleotide polymorphisms) typing.

DNA Probes↗

PubMed2004

A study of the conformations of valinomycin in solution phase.

Vibrational absorption and vibrational circular dichroism (VCD) spectra of valinomycin are measured, in different solvents, in the ester and amide carbonyl stretching regions. The influence of cations, namely Li(+), Na(+), K(+), and Cs(+), in methanol-d(4) solvent is also investigated. Ab initio quantum mechanical calculations using density functional theory and 6-31G* basis set are used to predict the absorption and VCD spectra. A bracelet-type structure for valinomycin that reproduces the experimental absorption and VCD spectra in inert solvents is identified. For the structure of valinomycin in polar solvents, a propeller-type structure was optimized, but further investigations are required to confirm this structure. A symmetric octahedral environment for the ester carbonyl groups in the valinomycin-K(+) complex is supported by the experimental VCD spectra. The results obtained in the present study demonstrate that even for large macrocyclic peptides, such as valinomycin, VCD can be used as an independent structural tool for the study of conformations in solution.

Amino Acid Sequence↗

PubMed2004

Detection of K-ras exon 1 mutations by constant denaturant capillary electrophoresis.

Among various mutation detection methods, constant denaturant capillary electrophoresis (CDCE) is one of the most common techniques for rapid identification of known or unknown mutations. In this report, a CDCE analysis method with homemade linear polyacrylamide (LPA) kit was developed on ABI 310 genetic analyzer, the effect and relationship of various denaturing factors in CDCE analysis were investigated and K-ras gene mutations of 31 coloerctal cancer patients were detected. Results indicate that, with the increase of chemical danaturant concentration, the optimum temperature was lowered, and when the concentration of urea (formamide) was higher than 7 M (40%), the homoduplex and heteroduplex of mutant samples were separated with difficulty. Detection results of K-ras gene in colorectal samples indicated that mutations were present in eight (26%) of 31 patients; most mutations were localized in codon 12, which is thought to be a critical step and plays an important role in human colorectal carcinogenesisas.

Acrylic Resins↗

PubMed2004

Fluorescent-based single-strand conformation polymorphism/heteroduplex capillary electrophoretic mutation analysis of the P53 gene.

Fluorescent-based single-strand conformation polymorphism (F-SSCP) analysis with capillary electrophoresis (CE) is the most common method for the detection of mutation because of its high sensitivity and resolution. In this study, we prepared an inexpensive linear polyacrylamide (LPA), and successfully applied it to CE-SSCP analysis and tandem CE-SSCP/heteroduplex analysis (HA) of the P53 gene on an ABI capillary genetic analyzer. A comparison of the sieving capabilities of a homemade LPA and commercial polydimethylacrylamide (PDMA) demonstrates that the homemade LPA has a higher resolution, a shorter analysis time, and is more suitable for tandem SSCP/HA than commercial PDMA. To show the usefulness, mutations of P53 gene exon 7 - 8 in 37 tumor samples were investigated by using homemade LPA. The results indicate that 10 mutations were found in 9 of 37 cases; the majority of P53 mutations were missense mutations, and 70% were located in exon 7, which plays an important role in neoplastic progression in human tumorigenesis.

Acrylic Resins↗

PubMed2003

Gene therapy with human tissue kallikrein reduces hypertension and hyperinsulinemia in fructose-induced hypertensive rats.

This study investigates gene therapy with human tissue kallikrein as a treatment for fructose-induced hypertension in rats. Hypertension was induced by addition of 10% fructose to drinking water. Fructose-fed rats also had increased serum insulin and triglycerides, decreased urine osmolarity, increased urine volume and endothelin-1, and increased aortic endothelin-1, endothelin-A receptor, and angiotensin II receptor type 1 mRNA levels. Fructose-induced hypertensive and control rats were injected intravenously with a construct containing the human tissue kallikrein cDNA. Two weeks after injection of hypertensive rats, systolic blood pressure and serum insulin levels normalized, urine osmolarity increased, urine endothelin-1 levels decreased, and aortic endothelin-1, endothelin-A receptor, and angiotensin II receptor type 1 mRNA levels decreased. In contrast, injection of the human tissue kallikrein cDNA had minimal effect on blood pressure or insulin levels in control rats. These results suggest that gene therapy with human tissue kallikrein may have potential as a treatment for hypertension and associated insulin resistance. Moreover, our data suggest that the beneficial effects of human tissue kallikrein on these parameters are associated with changes in endothelin-1, endothelin-A receptor, and angiotensin II receptor type 1 expression.

Animals↗

PubMed2003

Simultaneous genotyping of multiplex single nucleotide polymorphisms of the K-ras gene with a home-made kit.

Accurate and fast genotyping of single nucleotide polymorphisms (SNPs) is important in the human genome project. Here an automated fluorescent method that can rapidly and accurately genotype multiplex known SNPs was developed by using a homemade kit, which has lower cost but higher resolution than commercial kit. With this method, oncogene K-ras was investigated, four known SNPs of K-ras gene exon 1 in 31 coloerctal cancer patients were detected. Results indicate that mutations were present in 8(26%) of 31 patients, and most mutations were localized in codon 12. The presence of these mutations is thought to be a critical step and plays an important role in human colorectal carcinogenesisas.

Base Sequence↗

PubMed2003

A single-strand conformation polymorphism method by capillary electrophoresis with laser-induced fluorescence for detection of the T1151A mutation in hMLH1 gene.

Mutation of hMLH1 gene plays an important role in human tumorigenesis. A highly sensitive single-strand conformation polymorphism (SSCP) method for detection of the T1151A mutation in exon 12 of the hMLH1 gene was for the first time developed employing laser-induced fluorescence capillary electrophoresis (LIF-CE). Effects of the concentration of linear polyacrylamide solution, running temperature, running voltage and the addition of glycerol on SSCP analysis were investigated, and the optimum separation conditions were defined. Thirty colorectal cancer patients and eight lung cancer patients were screened and the T1151A mutation was found in four of them. Based on CE-sequencing the mutation was further confirmed. To our knowledge, this is for the first time that the T1151A mutation is found in lung cancer. Our method is simple, rapid, and highly sensitive and is well suited to the analysis of large numbers of clinical samples.

Adaptor Proteins, Signal Transducing↗