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Wei Xiao

Publications and source records attributed to Wei Xiao.

At least 19 recordsLinked to original sources
PubMed2026

[Mechanism of Tianshu Capsules in treating migraine rats based on gut microbiota].

This study aims to investigate the therapeutic effect of Tianshu Capsules(TS) on migraine rat model and explore its potential mechanism of action from the perspectives of the structure of the gut microbiota and functional pathway regulation. A migraine rat model was established via subcutaneous injection of nitroglycerin. The Sprague-Dawley rats were randomly divided into a control group, a model group, a low-dose TS group, a medium-dose TS group, a high-dose TS group, and an ibuprofen group. The efficacy of TS in improving migraine was evaluated by general condition observation and measurement of the craniofacial pain threshold. The expression of the gene c-fos in the trigeminal ganglion was determined by quantitative real-time polymerase chain reaction(PCR). The contents of endothelin-1(ET-1), calcitonin gene-related peptide(CGRP), and 5-hydroxytryptamine(5-HT) in serum were measured by enzyme-linked immunosorbent assay(ELISA). Fecal samples were subjected to metagenomic sequencing for systematic analysis of gut microbial diversity, taxonomic composition difference, and functional pathway changes of Kyoto Encyclopedia of Genes and Genomes(KEGG), and their correlations with behavioral and biochemical indices were further evaluated. The results show that TS significantly improves the increased body temperature and decreased craniofacial pain threshold in migraine rats. It also markedly suppresses the elevated expression levels of the gene c-fos in the trigeminal ganglion and reduces the levels of ET-1, CGRP, and 5-HT in serum. Metagenomic beta diversity analysis and differential taxonomic abundance analysis reveal that the migraine model induces significant gut microbiota dysbiosis, characterized by enrichment of harmful genera, including Streptococcus and Enterococcus, as well as a decline in the abundance of beneficial bacteria such as Allobaculum, Eubacterium, and Muribaculum. Functional pathway analysis results of KEGG further reveal that the relative abundances of pathways associated with biosynthesis of phenylalanine, tyrosine, and tryptophan, bacterial secretion system, citrate cycle, and biosynthesis of secondary metabolites are significantly decreased in the model group. TS intervention increased the abundance of the genus, such as Parabacteroides, Eubacterium, Allobaculum, and Muribaculum, while decreasing levels of microbiota, including Staphylococcus. TS also significantly upregulated pathways associated with barrier function(tight junction), amino acid biosynthesis pathways, and biosynthesis pathways of neurotransmitter precursors such as cysteine and methionine metabolism. In addition, it downregulated inflammatory pathways(Toll and IMD signaling) and pathways related to Staphylococcus aureus infection, thereby restoring the structure and function of the microbiota to a state close to those of the normal group. Spearman correlation analysis reveals that partial gut microbiota are significantly associated with migraine-related behavioral and biochemical indices(c-fos, ET-1, CGRP, and 5-HT). In conclusion, TS can regulate the disrupted gut microbiota structure and microbial functions related to neurotransmitter metabolism, intestinal barrier function, and inflammatory regulation in migraine model rats, which may be one of the potential key ways through which TS exert its anti-migraine effect.

Animals↗
PubMed2025

Association of AGER genetic variants with chronic obstructive pulmonary disease susceptibility in Southern Chinese Han populations.

OBJECTIVE: Chronic obstructive pulmonary disease (COPD) remains a leading cause of disability and mortality among elderly populations. Studies indicate that AGER plays a critical regulatory role in the pathogenesis of respiratory disorders. However, the genetic variations in AGER to COPD susceptibility remain incompletely understood. This study employs a case-control design to investigate associations between AGER genetic variants and COPD risk in the Southern Chinese Han population. METHODS: This study enrolled 270 COPD patients and 271 healthy controls. AGER single-nucleotide polymorphisms (SNPs) were analysed using the MassARRAY iPLEX platform. Logistic regression models evaluated associations between AGER polymorphisms and COPD susceptibility, with false discovery rate (FDR) correction applied to mitigate multiple testing errors. SNP-SNP interactions were investigated through multifactor dimensionality reduction (MDR) analysis. Expression quantitative trait locus (eQTL) data from the GTEx database were further analysed to assess regulatory relationships between SNPs and AGER gene expression levels. RESULTS: This study showed that rs3134941 (G allele, OR = 0.21, 95% CI = 0.10-0.41, p (FDR) = 0.001) and rs3131300 (G allele, OR = 0.32, 95% CI = 0.20-0.49, p (FDR) = 0.0001) were significantly associated with a reduced susceptibility to COPD. MDR indicated that rs3131300 was the optimal predictive model for COPD risk. Additionally, initial mechanistic investigations utilizing the GTEx database identify rs3134941 (C > G) and rs3131300 (A > G) as significant expression quantitative trait loci for AGER mRNA in cell-cultured fibroblasts and whole blood. CONCLUSION: Our study demonstrated that AGER genetic variants might play a protective role in the progression of COPD.

Aged↗
PubMed2007

Selectively oncolytic mutant of HSV-1 lyses HeLa cells mediated by Ras/RTN3.

The selectively oncolytic mtHSV, a HSV icp34.5 mutant with lacz gene insertion, was proved that it was targeted for treating tumors but not other organs, however, its oncolytic mechanism is under confirmation. The results showed that HeLa cells could be lysed efficiently by mtHSV in vitro. In the flow cytometry and Western blot experiment, Ras protein was obviously downregulated on plasma membrane (PM) while the whole Ras protein didn't change along with upregulation of reticulon 3(RTN3) protein at 48 h post infection of mtHSV in HeLa cells. Expression of Ras protein on PM and whole Ras protein in HeLa cells was downregulated by siFTa (inhibitor of a subunits of human farnesyltransferase with siRNA) and siRTN3(inhibitor of RTN3 with siRNA) respectively, and HeLa cells could be killed effectively by siFTa and siRTN3 at 48 h post transfection. So siFTa and siRTN3 effectively suppressed mtHSV infection of HeLa cells. Further, experiments were made to study the relationship between Ras and RTN3 using confocal colocalization and coimmunoprecipitation. The results exhibited that Ras could interact with RTN3 at endoplasmic reticulum. The data put forward that Ras/RTN3 is an important access to HeLa cells for mtHSV. The molecular interaction between Ras and RTN3 may further improve the understanding of the function of Ras and RTN3 in mtHSV infection. The results provide further theoretical evidence that mtHSV may be used as an oncolytic agent for cancer therapy.

Blotting, Western↗
PubMed2007

Three-phase interlines electrochemically driven into insulator compounds: a penetration model and its verification by electroreduction of solid AgCl.

A dynamic three-phase interline model has been developed for the reduction of a solid insulating metal compound to the metal in a suitable electrolyte, focusing on the electrochemically driven penetration of the process (or the three-phase interlines) into the insulator. Consideration is given to the effects of electrochemical, concentration and ohmic polarizations in the reduction-generated porous metal layer on top of the solid compound. Under potentiostatic conditions, reduction in the depth direction (penetration) becomes progressively slower as a result of the rising ohmic and concentration polarizations, whilst the electrochemical polarization exerts a declining effect. The quantitative equations established here also provide simple methods for the determination of some kinetic parameters of the reduction process, including rho (total resistivity) and D(R) (diffusion coefficient). The model has been experimentally verified by electrochemical reduction of solid AgCl with two novel metal|AgCl cylinder electrodes in aqueous solutions.

Journal Article↗
PubMed2006

DNA damage checkpoints are involved in postreplication repair.

Saccharomyces cerevisiae MMS2 encodes a ubiquitin-conjugating enzyme variant, belongs to the error-free branch of the RAD6 postreplication repair (PRR) pathway, and is parallel to the REV3-mediated mutagenesis branch. A mutation in genes of either the MMS2 or the REV3 branch does not result in extreme sensitivity to DNA-damaging agents; however, deletion of both subpathways of PRR results in a synergistic phenotype. Nevertheless, the double mutant is not as sensitive to DNA-damaging agents as a rad6 or rad18 mutant defective in the entire PRR pathway, suggesting the presence of an additional subpathway within PRR. A synthetic lethal screen was employed in the presence of a sublethal dose of a DNA-damaging agent to identify novel genes involved in PRR, which resulted in the isolation of RAD9 as a candidate PRR gene. Epistatic analysis showed that rad9 is synergistic to both mms2 and rev3 with respect to killing by methyl methanesulfonate (MMS), and the triple mutant is nearly as sensitive as the rad18 single mutant. In addition, rad9 rad18 is no more sensitive to MMS than the rad18 single mutant, suggesting that rad9 plays a role within the PRR pathway. Moreover, deletion of RAD9 reduces damage-induced mutagenesis and the mms2 spontaneous and induced mutagenesis is partially dependent on the RAD9 gene. We further demonstrated that the observed synergistic interactions apply to any two members between different branches of PRR and G1/S and G2/M checkpoint genes. These results suggest that a damage checkpoint is essential for tolerance mediated by both the error-free and error-prone branches of PRR.

Cell Cycle↗
PubMed2006

Structure and interactions of the ubiquitin-conjugating enzyme variant human Uev1a: implications for enzymatic synthesis of polyubiquitin chains.

Lys(63)-linked polyubiquitination of TRAF2 or TRAF6 is an essential step within the signal transduction cascade responsible for activation of p38, c-Jun N-terminal kinase, and the transcription factor NF-kappaB. Attachment of ubiquitin (Ub) to a TRAF, and conjugation of Ub molecules to form a polyUb chain, is catalyzed by a heterodimer composed of a catalytically active E2 (hUbc13), involved in covalent bond transfer, and hUev1a, an E2-like protein involved in substrate Ub binding. Given the key biochemical processes in which hUev1a is involved, it is important to determine the molecular basis of the catalytic mechanism for Lys(63)-linked protein ubiquitination. Nuclear magnetic resonance (NMR) spectroscopy was used to determine the structure of hUev1a and its interactions with Ub and hUbc13. A structural model for the Ub-hUev1a-hUbc13-Ub tetramer was developed to gain chemical insight into the synthesis of Lys(63)-linked Ub chains. We propose that a network of hydrogen bonds involving hUbc13-Asp(81) and Ub-Glu(64) positions Ub-Lys(63) proximal to the active site. Interestingly, restrained molecular dynamics simulations in implicit solvent indicate that deprotonation of Ub-Lys(63) does not involve a general Asp or Glu base and may occur when the amino group approaches the thioester carbonyl carbon near the Bürgi-Dunitz trajectory.

Dimerization↗
PubMed2006

Electrochemically driven three-phase interlines into insulator compounds: electroreduction of solid SiO2 in molten CaCl2.

The electrochemical reduction of solid SiO2 (quartz) to Si is studied in molten CaCl2 at 1173 K. Experimental observations are compared and agree well with a novel penetration model in relation with electrochemistry at the dynamic conductor|insulator|electrolyte three-phase interlines. The findings show that the reduction of a cylindrical quartz pellet at certain potentials is mainly determined by the diffusion of the O(2-) ions and also the ohmic polarisation in the reduction-generated porous silicon layer. The reduction rate increases with the overpotential to a maximum after which the process is retarded, most likely due to precipitation of CaO in the reaction region (cathodic passivation). Data are reported on the reduction rate, current efficiency and energy consumption during the electroreduction of quartz under potentiostatic conditions. These theoretical and experimental findings form the basis for an in-depth discussion on the optimisation of the electroreduction method for the production of silicon.

Journal Article↗
PubMed2006

Identification and characterization of CRT10 as a novel regulator of Saccharomyces cerevisiae ribonucleotide reductase genes.

The CRT10 gene was identified through screening of the Saccharomyces cerevisiae deletion library for hydroxyurea (HU) resistance. CRT10 encodes a putative 957 amino acid, 110 kDa protein with a leucine repeat and a WD40 repeat near the N-terminus. Deletion of CRT10 resulted in an enhanced resistance to HU reminiscent of the inactivation of two other ribonucleotide reductase (Rnr) suppressors, CRT1 and SML1, which regulate Rnr activity at transcriptional and translational levels, respectively. Epistatic analysis indicates that CRT10 belongs to the CRT1 pathway but not the SML1 pathway. Indeed, deletion of CRT10 enhanced the survival of the mec1 null mutant and increased basal level and DNA damage-induced expression of RNR2 and RNR3, suggesting that Crt10 regulates RNR genes at the transcriptional level. Furthermore, the dun1 mutation is epistatic to crt10 with respect to both HU sensitivity and RNR gene expression. Interestingly, the expression of CRT10 itself is induced by DNA damaging agents and this induction requires DUN1, suggesting that CRT10 plays a role in cellular response to DNA damage and replication blocks. The CRT10 function appears to be achieved by positive regulation of the CRT1 transcript level, indicating that CRT10 is a component of the regulatory circuit.

Base Sequence↗
PubMed2006

Adenovirus E1A reverses the resistance of normal primary human lung fibroblast cells to TRAIL through DR5 upregulation and caspase 8-dependent pathway.

Expression of the adenovirus serotype 5 (Ad5) E1A enhances tumor cells to apoptosis by TNF-alpha, Fas-ligand and TNF-related apoptosis-inducing ligand (TRAIL). In this study, we found that E1A expression reversed the resistance of normal primary human lung fibroblast cells (P-HLF) to TRAIL-induced apoptosis. Furthermore, TRAIL dramatically induced apoptosis of P-HLF cells that expressed E1A following either infection with Ad-E1A or transfection with pcDNA3-E1A. Further results demonstrated that E1A specifically upregulated DR5 levels but had nearly no effect on the levels of DR4. E1A dramatically upregulated the exogenous TRAIL, and then increased a substantial amount of TRAIL on the surface of P-HLF cells treated with the expression vectors, both Ad-TRAIL and pIRES-EGFP-TRAIL. The dominant negative FADD mutation (FADD-DN) results revealed that the apoptosis in Ad-E1A and Ad-TRAIL coinfected P-HLF cells was completely blocked following inhibition of the death receptors-associated apoptosis-inducing molecules FADD. Moreover, the caspase 8 inhibitor (Z-IETD-FMK) could efficiently block caspase 8 activation and resulted in inhibition of caspase 3 activation and cleavage. However, The caspase 9 specific inhibitor (Z-LEHD-FMK) could not counteract the synergistic effect of TRAIL-induced apoptosis in combination with E1A, and caspase 3 activation and cleavage were not inhibited by Z-LEHD-FMK. Thus, our results suggest that adenovirus E1A sensitizes P-HLF cells to TRAIL-induced apoptosis involving DR5 upregulation and the caspase 8-dependent pathway. These findings provide the first direct evidence for molecular mechanisms of adenovirus E1A gene products to sensitize normal cells to TRAIL-mediated apoptosis.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Uev1A, a ubiquitin conjugating enzyme variant, inhibits stress-induced apoptosis through NF-kappaB activation.

We have previously shown that UEV1 is up-regulated in all tumor cell lines examined and when SV40-transformed human embryonic kidney cells undergo immortalization; however, it is unclear whether and how UEV1 plays a critical role in this process. UEV1A encodes a ubiquitin conjugating enzyme variant, which is required for Ubc13 (ubiquitin conjugating enzyme) catalyzed poly-ubiquitination of target proteins through Lys63-linked chains. One of the target proteins is NEMO/IKKgamma (nuclear factor-kappaB essential modulator/inhibitor of kappaB protein kinase), a regulatory subunit of IkappaB kinase in the NF-kappaB signaling pathway. In this report, we show that constitutive high-level expression of UEV1A alone in cultured human cells was sufficient to cause a significant increase in NF-kappaB activity as well as the expression of its target anti-apoptotic protein, Bcl-2 (B-cell leukemia/lymphoma 2). Overexpression of UEV1A also conferred prolonged cell survival under serum-deprived conditions, and protected cells against apoptosis induced by diverse stressing agents. All of the effects of Uev1A were reversible upon suppression of UEV1 expression by RNA interference. Our observations presented in this report provide evidence that Uev1A is a critical regulatory component in the NF-kappaB signaling pathway in response to environmental stresses and identify UEV1A as a potential proto-oncogene.

Apoptosis↗
PubMed2006

Structural basis for non-covalent interaction between ubiquitin and the ubiquitin conjugating enzyme variant human MMS2.

Modification of proteins by post-translational covalent attachment of a single, or chain, of ubiquitin molecules serves as a signaling mechanism for a number of regulatory functions in eukaryotic cells. For example, proteins tagged with lysine-63 linked polyubiquitin chains are involved in error-free DNA repair. The catalysis of lysine-63 linked polyubiquitin chains involves the sequential activity of three enzymes (E1, E2, and E3) that ultimately transfer a ubiquitin thiolester intermediate to a protein target. The E2 responsible for catalysis of lysine-63 linked polyubiquitination is a protein heterodimer consisting of a canonical E2 known as Ubc13, and an E2-like protein, or ubiquitin conjugating enzyme variant (UEV), known as Mms2. We have determined the solution structure of the complex formed by human Mms2 and ubiquitin using high resolution, solution state nuclear magnetic resonance (NMR) spectroscopy. The structure of the Mms2-Ub complex provides important insights into the molecular basis underlying the catalysis of lysine-63 linked polyubiquitin chains.

Humans↗
PubMed2006

Arabidopsis thaliana UBC13: implication of error-free DNA damage tolerance and Lys63-linked polyubiquitylation in plants.

Ubiquitylation is an important biochemical reaction found in all eukaryotic organisms and is involved in a wide range of cellular processes. Conventional ubiquitylation requires the formation of polyubiquitin chains linked through Lys48 of the ubiquitin, which targets specific proteins for degradation. Recently polyubiquitylation through a noncanonical Lys63 chain has been reported, and is required for error-free DNA damage tolerance (or postreplication repair) in yeast. To date, Ubc13 is the only known ubiquitin-conjugating enzyme (Ubc) capable of catalyzing the Lys63-linked polyubiquitylation reaction and this function requires interaction with the Ubc variant Mms2. No information is available on either Lys63-linked ubiquitylation or error-free damage tolerance in plants. We thus cloned and functionally characterized two Arabidopsis thaliana UBC13 genes, AtUBC13A and AtUBC13B. The two genes are highly conserved with respect to chromosomal structure and protein sequence, suggesting that they are derived from a recent gene duplication event. Both AtUbc13 proteins are able to physically interact with yeast or human Mms2, implying that plants also employ the Lys63-linked polyubiquitylation reaction. Furthermore, AtUBC13 genes are able to functionally complement the yeast ubc13 null mutant for spontaneous mutagenesis and sensitivity to DNA damaging agents, suggesting the existence of an error-free DNA damage tolerance pathway in plants. The AtUBC13 genes appear to express ubiquitously and are not induced by various conditions tested.

Amino Acid Sequence↗
PubMed2006

Mating type regulation of cellular tolerance to DNA damage is specific to the DNA post-replication repair and mutagenesis pathway.

In order to help further define DNA post-replication repair (PRR), a conditional synthetic lethal screen was employed to identify new genes involved in the PRR pathway. A synthetic lethal screen with the mms2 mutation resulted in the recovery of two suppressor mutations responsible for regulating PRR. The recovered suppressors are the mating type genes and SIR3. Indeed, controlled expression of both mating type genes or deletion of SIR3 rescued the conditional synthetic lethal mutant phenotypes. Furthermore, comprehensive analyses suggest that mating type heterozygosity confers tolerance to a broad range of DNA damage, and that this effect is limited to all PRR pathway mutations, but does not apply to base excision repair, nucleotide excision repair or recombination repair mutants. In addition, the tolerance conferred to PRR mutants as a result of mating type heterozygosity is dependent on a functional homologous recombination but not the non-homologous end-joining pathway. Thus, mating type status appears to be responsible for signalling DNA content and possibly cell cycle stage, allowing the cell to select the most efficient means to repair the DNA damage.

Base Sequence↗
PubMed2006

Isolation of nucleic acids.

Saccharomyces cerevisiae is an excellent model organism for the study of eukaryotic genetics. Easy manipulation of yeast DNA is essential to its role in research, and studies of gene expression or regulation require analysis of RNA. This chapter presents quick and straightforward methods to isolate genomic DNA, plasmid DNA, or RNA from yeast. The isolation protocols presented here, which utilize a glass bead method to break through the cell wall, will yield plasmid DNA of sufficient quality to transform into Escherichia coli, genomic DNA that can be digested with restriction enzymes for Southern blotting, or RNA for use in applications such as Northern blots.

DNA, Fungal↗
PubMed2006

Mutagenesis.

To identify new genes in an organism, a genetic approach can be used to screen for mutations that display a particular phenotype. Genotoxic agents, such as ultraviolet (UV) light, ionizing radiation, or chemicals can be used to randomly induce DNA lesions in the genome. Most efficient mutagenesis occurs when a mutagen confers a high frequency of mutations with low lethality, in the range of 10 to 50% survival. These mutations can be in the form of frameshifts, deletions, or rearrangements. To initiate a mutagenesis, a fresh subculture of cells grown into log phase is collected, washed, and resuspended in potassium phosphate buffer. The mutagen is added to the culture for a predetermined time, deactivated, and washed from the cells. The cells are allowed to recover from the treatment by incubating in liquid or on solid medium. Mutants can be isolated by screening individual colonies or by using direct selection of cells from the mutagenized cell population.

4-Nitroquinoline-1-oxide↗
PubMed2006

Synthetic lethal screen.

The synthetic lethal screen is a method of isolating novel mutants whose survival is dependent on a gene of interest. Combining the colony-color assay with a synthetic lethal screen offers a means to visually detect a mutant that depends on a plasmid for survival. Screening for synthetic lethals can be achieved in four steps. First, the gene of interest must be mutated in a strain harboring the ade2 ade3/ade8 mutations and producing white colonies. A plasmid containing the ADE3/ADE8 gene and the wild-type gene of interest must then be transformed into the strain, which results in red colonies with white sectors where the plasmid has been lost. A mutagenesis is then required to introduce random mutations into the yeast genome. Any cell with a mutation that causes dependence on the gene of interest for survival must maintain the plasmid; these cells will produce solid red colonies. Finally, the mutants are transformed with a library. The mutants containing complementing DNA are no longer dependent on the plasmid carrying the gene of interest and thus the synthetic lethals are identified by their red-white sectoring phenotype. The synthetic lethal gene can be identified by isolating and sequencing plasmid DNA.

Gene Library↗
PubMed2006

Study of transcriptional regulation using a reporter gene assay.

Study of gene expression can be facilitated by using a reporter gene assay. Instead of directly measuring the level of target gene mRNA, one can clone the promoter region of the gene of interest in front of a reporter gene and measure the reporter gene expression as a reflection of the expression of the gene of interest. We describe a simple lacZ-fusion system to measure the activity of the reporter gene product beta-galactosidase. Different strategies of making the fusion construct and their applications are also discussed. This method is particularly useful to dissect the promoter region of the gene of interest and is also used in other experimental protocols such as the yeast two-hybrid analysis.

Artificial Gene Fusion↗