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Y Q Wu

Publications and source records attributed to Y Q Wu.

At least 19 recordsLinked to original sources
PubMed2026

ARID1A Mediates ROS-Induced Osteoclast Activation in TMJ Osteoarthritis.

Excessive osteoclast activation drives rapid subchondral bone destruction, serving as a critical early-stage event precipitating temporomandibular joint osteoarthritis (TMJ-OA). Although epigenetic remodeling is widely recognized as an important interface between pathological environmental signals and genomic response, the specific epigenetic mechanisms translating TMJ-OA-associated stimulation into pathological osteoclast activation remain to be elucidated. Here, using a mechanically induced TMJ-OA mouse model, we identify aberrant reactive oxygen species (ROS) accumulation as a critical upstream driver initiating excessive osteoclast activation and subsequent joint deterioration. By integrating transcriptomic and epigenomic analyses, we delineate the chromatin remodeler AT-rich interaction domain 1A (ARID1A) as an essential oxidative stress sensor within the osteoclast lineage. Mechanistically, ROS accumulation induces ARID1A upregulation and recruitment to the Src enhancer, transcriptionally activating Src and amplifying PI3K-AKT signaling to drive pathological osteoclastogenesis. Conditional knockout of Arid1a in myeloid cells effectively abrogates subchondral bone loss and cartilage destruction in TMJ-OA. Translating these mechanistic insights, we engineered an ROS-responsive, osteoclast-targeting hydrogel for the on-demand delivery of an ARID1A-dependent canonical BRG1/BRM-associated factor complex inhibitor, which successfully alleviates TMJ-OA progression. Our findings establish the epigenetic response to ROS accumulation as a key pathogenic mechanism in TMJ-OA and highlight ARID1A as a promising therapeutic target for early disease intervention.

biomaterial(s)↗
PubMed2006

Genetic diversity of sorghum accessions resistant to greenbugs as assessed with AFLP markers.

Sorghum, Sorghum bicolor (L.) Moench, is the fifth most important cereal crop grown worldwide and the fourth in the United States. Greenbug, Schizaphis graminum (Rondani), is a major insect pest of sorghum with several biotypes reported to date. Greenbug biotype I is currently the most prevalent and most virulent on sorghum plants. Breeding for resistance is an effective way to control greenbug damage. A successful breeding program relies in part upon a clear understanding of breeding materials. However, the genetic diversity and relatedness among the greenbug biotype I resistant accessions collected from different geographic origins have not been well characterized, although a rich germplasm collection is available. In this study, 26 sorghum accessions from 12 countries were evaluated for both resistance to greenbug biotype I and genetic diversity using fluorescence-labeled amplified fragment length polymorphism (AFLP). Twenty-six AFLP primer combinations produced 819 polymorphic fragments indicating a relatively high level of polymorphism among the accessions. Genetic similarity coefficients among the sorghum accessions ranged from 0.69 to 0.90. Cluster analysis indicated that there were two major groups based on polymorphic bands. This study has led to the identification of new genetic sources of sorghum with substantial genetic variation and distinct groupings of resistant accessions that have the potential for use in the development of durable greenbug resistant sorghum.

Animals↗
PubMed2004

AFLP analysis of Cynodon dactylon (L.) Pers. var. dactylon genetic variation.

Cynodon dactylon (L.) Pers. var. dactylon (common bermudagrass) is geographically widely distributed between about lat 45 degrees N and lat 45 degrees S, penetrating to about lat 53 degrees N in Europe. The extensive variation of morphological and adaptive characteristics of the taxon is substantially documented, but information is lacking on DNA molecular variation in geographically disparate forms. Accordingly, this study was conducted to assess molecular genetic variation and genetic relatedness among 28 C. dactylon var. dactylon accessions originating from 11 countries on 4 continents (Africa, Asia, Australia, and Europe). A fluorescence-labeled amplified fragment length polymorphism (AFLP) DNA profiling method was used to detect the genetic diversity and relatedness. On the basis of 443 polymorphic AFLP fragments from 8 primer combinations, the accessions were grouped into clusters and subclusters associating with their geographic origins. Genetic similarity coefficients (SC) for the 28 accessions ranged from 0.53 to 0.98. Accessions originating from Africa, Australia, Asia, and Europe formed major groupings as indicated by cluster and principal coordinate analysis. Accessions from Australia and Asia, though separately clustered, were relatively closely related and most distantly related to accessions of European origin. African accessions formed two distant clusters and had the greatest variation in genetic relatedness relative to accessions from other geographic regions. Sampling the full extent of genetic variation in C. dactylon var. dactylon would require extensive germplasm collection in the major geographic regions of its distributional range.

Cynodon↗
PubMed2001

Loss of heterozygosity of the putative prostate cancer susceptibility gene HPC2/ELAC2 is uncommon in sporadic and familial prostate cancer.

The recognition that prostate cancer clusters within families has led to the search for prostate cancer susceptibility genes. Recently, the HPC2/ELAC2 gene on chromosome 17p has been identified as a potential prostate cancer predisposition gene using both family based as well as case-control studies. Many cancer susceptibility genes act as tumor suppressor genes in which inactivation of one allele in the tumor can be detected via loss of heterozygosity (LOH). To determine whether the HPC2/ELAC2 gene demonstrates significant LOH in sporadic and familial prostate cancers, paired tumor and normal DNA samples were isolated using microdissection techniques from 44 radical prostatectomy specimens. Cases were analyzed using a panel of markers in the following order: TP53-D17S969-D17S947-(HPC2/ELAC2)-D17S799-D17S936. LOH was observed in < 10% of cases using the four markers that map to the HPC2/ELAC2 region. However, allelic loss was observed at the TP53 gene in 25% of informative cases. Taken together, inactivation of the HPC2/ELAC2 gene via LOH is a relatively uncommon event in prostate cancer. Future studies will determine whether 17p LOH occurs in the subset of patients with an inherited mutation in HPC2/ELAC2.

Adult↗
PubMed2001

Identification of a human brain-specific gene, calneuron 1, a new member of the calmodulin superfamily.

The calmodulin superfamily includes the calmodulins, calcium-binding proteins, and related genes. Herein, we describe the cloning and characterization of human calneuron 1 (CALN1). CALN1 encodes a novel neuron-specific protein that maps to chromosome 7q11. CALN1 spans a large genomic region (>360 kb). Sequence comparison shows significant similarity with the calmodulin superfamily of genes, especially in the two conserved EF-hand motifs. The mouse orthologous gene (Caln1) shows little prenatal expression, with highest expression at Postnatal Day 21. In situ hybridization to adult mouse brain shows high expression in the cerebellum, hippocampus, and cortex. The high expression of this gene exclusively in brain, the developmental changes in expression levels, the high homology with calmodulin which indicates a potential role in signal transduction, and the cellular localization of the mRNA suggest that CALN1 has a significant role in the physiology of neurons and is potentially important in memory and learning.

Amino Acid Sequence↗
PubMed2001

Characterization of an ATP-dependent type I DNA ligase from Arabidopsis thaliana.

Here we report the purification and biochemical characterization of recombinant Arabidopsis thaliana DNA ligase I. We show that this ligase requires ATP as a source for adenylation. The calculated Km [ATP] for ligation is 3 microM. This enzyme is able to ligate nicks in oligo(dT)/poly(dA) and oligo(rA)/poly(dT) substrates, but not in oligo(dT)/poly(rA) substrates. Double-stranded DNAs with cohesive or blunt ends are also good substrates for the ligase. These biochemical features of the purified enzyme show the characteristics typical of a type I DNA ligase. Furthermore, this DNA ligase is able to perform the reverse reaction (relaxation of supercoiled DNA) in an AMP-dependent and PPi-stimulated manner.

Adenosine Triphosphate↗
PubMed2001

Loss of the potassium channel beta-subunit gene, KCNAB2, is associated with epilepsy in patients with 1p36 deletion syndrome.

PURPOSE: Clinical features associated with chromosome 1p36 deletion include characteristic craniofacial abnormalities, mental retardation, and epilepsy. The presence and severity of specific phenotypic features are likely to be correlated with loss of a distinct complement of genes in each patient. We hypothesize that hemizygous deletion of one, or a few, critical gene(s) controlling neuronal excitability is associated with the epilepsy phenotype. Because ion channels are important determinants of seizure susceptibility and the voltage-gated K(+) channel beta-subunit gene, KCNAB2, has been localized to 1p36, we propose that deletion of this gene may be associated with the epilepsy phenotype. METHODS: Twenty-four patients were evaluated by fluorescence in situ hybridization with a probe containing KCNAB2. Clinical details were obtained by neurologic examination and EEG. RESULTS: Nine patients are deleted for the KCNAB2 locus, and eight (89%) of these have epilepsy or epileptiform activity on EEG. The majority of patients have a severe seizure phenotype, including infantile spasms. In contrast, of those not deleted for KCNAB2, only 27% have chronic seizures, and none had infantile spasms. CONCLUSIONS: Lack of the beta subunit would be predicted to reduce K(+) channel-mediated membrane repolarization and increase neuronal excitability, suggesting a possible relation between loss of this gene and the development of seizures. Because some patients with seizures were not deleted for KCNAB2, there may be additional genes within 1p36 that contribute to epilepsy in this syndrome. Hemizygosity of this gene in a majority of monosomy 1p36 syndrome patients with epilepsy suggests that haploinsufficiency for KCNAB2 is a significant risk factor for epilepsy.

Adolescent↗
PubMed2001

Meiotic human sperm cells express a leucine-rich homologue of Caenorhabditis elegans early embryogenesis gene, Zyg-11.

We cloned a human protein (Hzyg) homologue to Caenorhabditis elegans Zyg-11, an essential protein for cell division at the initial developmental stages of this species, and to a Drosophila melanogaster gene product (Mei-1) which is likely to be involved in meiosis. Hzyg mRNA encodes a protein of 766 amino acids (88 kDa), 14% of which are leucine residues, with some being arranged in four leucine rich repeat motives usually involved in protein-protein interactions. Hzyg is encoded by a single gene, located on chromosome 9q32-q34.1, and transcribed as two mRNA: a 5 kb transcript strongly expressed in testis and skeletal muscle and barely detectable in other human tissues, and an abundant 3.1 kb mRNA detected only in the testis. By using in-situ hybridization and immunohistochemistry, we clearly established the presence of Hzyg expression in pachytene spermatocytes (stage V) and spermatids (stage I and/or II) around the time of meiosis. The cell specific expression of Hzyg transcripts in testis, and the conservation of this gene among distant species, suggest that this protein may have an important role during meiosis.

Adenosine Triphosphatases↗
PubMed2001

Isolation and Analysis of hupR Gene Required for the Expression of Hydrogenase in Rhodobacter sphaeroides.

Cosmid 1 containing the hup genes isolated from the photosynthetic bacterium Rhodobacter sphaeroides was studied. The hupR gene from cosmid 1 was cloned and sequenced (EMBL accession number AJ243734). It encoded a 54.031 kD protein homologous to transcriptional regulators belonging to the superfamily of two-component regulatory systems. The HupR protein was overexpressed in Escherichia coli in the form of His6-tagged HupR. The cloned hupR gene could restore hydrogenase activity in R.sphaeroides hupR mutants and activate hupSL gene transcription.

Journal Article↗
PubMed2000

Clusterin protein diversity in the primate eye.

PURPOSE: The clusterin gene encodes a multi-functional protein that has been identified in different tissues, including a number of different eye tissues, primarily in the mouse and to a much lesser extent in humans. Clusterin has been implicated in a number of cellular processes such as lipid transport, membrane integrity, apoptosis, and neurodegeneration, all of which could be important to the biology of the eye. In the current communication, we provide data that confirms the expression of clusterin in a number of different human eye tissues and establishes the expression profile of this gene in monkey derived eye tissues. The issue that we sought to examine is whether a broad profile of clusterin expression in the eye is consistent in primates (monkey and human). METHODS: The majority of our study was done using monkey eye tissues. Where possible, we have used human tissues in order to confirm published findings. Northern and western analysis was performed using tissues derived from monkey eyes. In situ hybridization and immunochemistry were carried out on human eye sections. RESULTS: Clusterin mRNA is expressed in primate lens, cornea, limbus, sclera, orbital muscle, ciliary body, retina, RPE/choroid, and RPE cells in culture. Western analysis revealed that two major groups of clusterin exist in the eye, a high molecular weight group (>100 kDa) and a second group consisting of at least five clusterin species that are all approximately 80 kDa. Analysis of conditioned media from RPE cells cultured on permeable supports suggests that different forms of clusterin display alternative patterns of secretion. CONCLUSIONS: Clusterin is expressed in a broad range of eye tissues in both human and monkey, suggesting that this is a characteristic feature in primates. We demonstrate for the first time that a diverse number of clusterin isoforms were observed in monkey eye tissues by western analysis. Meanwhile, the molecular size of clusterin mRNA detected in the array of tissues are identical in size, suggesting that the nature of the diversity in clusterin forms is due to post-translational modifications. In addition, new insights were made in defining clusterin expression in ciliary body, cornea, and the retinal pigment epithelium.

Animals↗
PubMed2000

Haploinsufficiency of ALX4 as a potential cause of parietal foramina in the 11p11.2 contiguous gene-deletion syndrome.

Heterozygous mutations in MSX2 are responsible for an autosomal dominant form of parietal foramina (PFM). PFM are oval defects of the parietal bones that are also a characteristic feature of a contiguous gene-deletion syndrome caused by a proximal deletion in the short arm of chromosome 11 (Potocki-Shaffer syndrome). We have identified a human bacterial artificial chromosome (BAC) clone mapping to chromosome 11, containing a region homologous to the human homeobox gene MSX2. Further sequence analysis demonstrated that the human orthologue (ALX4) of the mouse Aristaless-like 4 gene (Alx4) is contained within this 11p clone. We used FISH to test for the presence-or for the heterozygous deletion-of this clone in two patients with the 11p11.2-deletion syndrome and showed that this clone is deleted in these patients. ALX4 and Alx4 were shown to be expressed in bone and to be absent from all other tissues tested. The involvement of Alx4 in murine skull development, its bone-specific expression pattern, the fact that Alx4 is a dosage-sensitive gene in mice, and the localization of a human genomic clone containing ALX4 to 11p11.2, with hemizygosity in patients with deletion of 11p11.2 who have biparietal foramina, support the contention that ALX4 is a candidate gene for the PFM in the 11p11.2-deletion syndrome.

Amino Acid Sequence↗
PubMed2000

Acarbose partially inhibits microvascular retinopathy in the Zucker Diabetic Fatty rat (ZDF/Gmi-fa).

We compared quantitative capillary retinopathic changes between non-insulin-dependent diabetic Zucker Diabetic Fatty (ZDF) rats and heterozygous nondiabetic Zucker controls and evaluated the effect of an orally administered glucosidase inhibitor, acarbose, on retinopathy in these animals. Four groups of eight rats were analyzed: treated and untreated ZDF and treated and untreated Zuckers. Retinal capillary basement membrane thickening and retinal capillary cell density were determined from transmission electron microscopy and trypsin digestion preparations. ZDF rats had thicker basement membranes (p<0.0001) and more cells per unit capillary length (p=0.0003) compared to Zuckers. Acarbose treatment significantly reduced basement membrane thickening in the treated ZDF rats (p=0.001), but the effects on cell density showed only a favorable trend. Acarbose treatment has an ameliorative effect on the development of microvascular retinopathy in the ZDF rat, probably due to lessening of hyperglycemia.

Acarbose↗
PubMed2000

[Studies of the genetic polymorphism of Schistosoma japonicum (Chinese mainland strains)].

In order to analyze the interspecies diversity and the extent of diversity among Schistosoma japonicum Chinese mainland strains, the genetic variation on gene level among 6 isolates collected from Jiangxi, Hunan, Hubei, Anhui, Sichuan, Yunnan and a cultured isolate from a laboratory were studied using molecular biological technique. There were only two different bases at position 112 and 143 in 536 bp sequence of 28S rDNA-D2 domain between Anhui and Yunnan isolates, the homology was 99.6%. The result could be explained the reason of why the migration rates of single chain 28S rDNA-D2 domain among the above 7 isolates were the same completely in PCR-SSCP. However, comparing with the sequences of the Philippine isolate of S. japonicum, S. mansoni and S. aematobium, there were 6, 94 and 93 different bases and the homologies were 98.9, 82.5 and 82.7 per cent separately. With 8 restriction endonucleases to analyze the ITS of rDNA obtained by PCR from the 7 isolates, the results showed that only 3 minor bands were different, e.g. 5.3% of total 58 fragments. It was suggested that the ITS of rDNA among 7 isolates were highly conserved. Using randomly amplified polymorphic DNA (RAPD) to analyze the genetic diversity of the genomes of the 7 isolates, the average genetic distance (D) calculated from total 284 amplified fragments was 0.22. The maximum D was 0.30 and existed between Anhui and Yunnan isolates. The minimum D was 0.13 and existed between Sichuan and Yunnan isolates. The clustering analysis of genetic distances showed that the 7 isolates could be gathered in one group. From above three results, it could be considered that the genetic diversity on gene level among S. japonicum Chinese mainland strains was very low.

Animals↗
PubMed2000

[Expression of single-chain Fv antibody for anti-beet necrotic yellow vein virus in Escherichia coli].

The heavy chains variable region gene (VH) of monoclonal antibody against beet necrotic yellow vein virus (BNYVV) was amplified from total DNA extracted from anti-BNYVV hybridoma cells by PCR. Sequencing showed that the VH belongs to mouse subgroup II(A) and contains 360 bp, which code one hundred and twenty amino acids. The VH and VL genes were inserted into a plasmid which contains a linker sequence for constructing scFv gene. The new vector named pTC scFv. The scFv was produced in Escherichia coli and appeared binding activity with BNYVV antigen by ELISA method.

Amino Acid Sequence↗
PubMed2000

Prostacyclin-induced relaxations of small porcine pulmonary arteries are enhanced by the basal release of endothelium-derived nitric oxide through an effect on cyclic GMP-inhibited-cyclic AMP phosphodiesterase.

AIM: To study the interactions between prostacyclin and endothelium-derived nitric oxide in porcine pulmonary arteries. METHODS: Rings of 5th order of porcine pulmonary arteries were studied in vitro for the measurement of tension and the content in cyclic nucleotides. RESULTS: Prostacyclin, given exogenously, caused endothelium-potentiated relaxations (inhibition of phenylephrine contraction) that were inhibited by the inhibitors of the L-arginine nitric oxide pathway, oxyhemoglobin and N omega-nitro-L-arginine. These inhibitors did not affect the tension in rings without endothelium. Cyclic GMP-concentrations were not increased above basal concentrations in the presence of prostacyclin. Increases were seen with acetylcholine and sodium nitroprusside. Prostacyclin-stimulated cyclic AMP concentrations did not reach statistical significance compared to controls. The addition of 8-bromo-cyclic GMP to prostacyclin, however, increased the cyclic AMP content. The nitric oxide synthase inhibitor, nitro-L-arginine (NLA), reduced the prostacyclin-stimulated cyclic AMP content to basal level. Inhibition of cyclic GMP-inhibited cyclic AMP phosphodiesterase by 8-bromo-cyclic GMP or amrinone (a specific inhibitor of this enzyme) potentiated the prostacyclin-induced relaxations in rings without endothelium to a magnitude similar to that observed in rings with endothelium. CONCLUSION: These data suggest that the augmentation by the endothelium of the prostacyclin-induced relaxation of porcine pulmonary arteries is secondary to the inhibition of cyclic GMP-inhibited cyclic AMP phosphodiesterase by basally released endothelium-derived nitric oxide.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2000

The expression of E-cadherin-catenin complex in adenoid cystic carcinoma of salivary glands.

OBJECTIVE: The aim of this study was to investigate the expression of the E-cadherin-catenin (E-cad-cat) complex in human salivary adenoid cystic carcinoma (ACC) and determine the effects of E-cad-cat expression on tumor differentiation, metastasis, and invasion, as well as its clinical significance. METHODS: The expression of adhesion molecules, which included E-cadherin, alpha-catenin, and beta-catenin, on 10 cases of normal salivary glands, and 50 cases of human salivary ACC were investigated by immunohistochemistry. RESULTS: Strong and stable expression of E-cad-cat complex showed in normal salivary glands tissues. However, weaker expression and even complete absence, of the positive signals were shown on all ACC cases. Coexpression of E-cad-cat were detected in 29 (58%) of the 50 ACC specimens. Positive staining of E-cad-cat complex were detected in 7 (39%) of the 18 ACC primary sites that had aggressive phenotype of nerve and vasculature. CONCLUSION: Strong positive signals of E-cad-cat complex are shown in normal salivary glands, and the down-regulated expression were observed in ACC cases. The expression of E-cad-cat complex is associated with a more aggressive phenotype on nerve and vasculature. No association with various histopathologic subtypes was found. However, absent or low E-cad expression was observed more frequently in solid carcinomas than in cribriform or tubular carcinomas. Down-regulation of E-cad-cat complex may be associated with canceration of normal salivary glands. The expression levels of E-cad-cat were positively correlated to the differentiation of ACC tumor cells.

Antibodies, Monoclonal↗
PubMed2000

[Effects of culture conditions on callus growth and taxol formation of Taxus yunnanensis Cheng et L.K.Fu].

OBJECTIVE: To seek culture conditions suitable for the callus growth and taxol formation of Taxus yunnanensis. METHOD: Determining the growth index and taxol content in the callus cultured under different illumination conditions or on different media. RESULTS AND CONCLUSION: Darkness, the combination of 0.1 mg.L-1BAP and 2,4-D 1.0 mg.L-1, and B5, DCR or 6,7-V basal medium were favorable for the callus growth and taxol formation of Taxus yunnanensis; high NO3- concentration in the medium promoted callus growth, and high NH4+ concentration greatly inhibited callus growth, but dramatically increased taxol content.

Culture Media↗