Biomedical subjects

Xiao-Gang Zhou

Publications and source records attributed to Xiao-Gang Zhou.

6 recordsLinked to original sources

PubMed2006

[Analysis of the secreted proteins encoded by genes in genome of filamental fungus (Neurospora crassa)].

The completed genome sequence of filamental fungus Neurospora crassa has completed and 10,082 open reading frames (ORFs) were predicted in whole genome. Among them, 437 proteins were secreted ones based on the combination of prediction algorithms SignalP v3.0 and PSORT, transmembrane domains prediction algorithms TMHMM v2.0 and THUMBUP, potential GPI-anchor sites prediction algorithm big-PI predictor and the subcellular protein location prediction algorithm TargetP v1.01. The minimum ORF length of the encoding sequences for 437 secreted proteins was 252 bp, the maximum ORF length was 6 604 bp and average was 1 433 bp. The length of signal peptide of secreted proteins ranged from 15 to 59 amino acids. Among the 437 secreted proteins, 205 were provided with function description. The function of secretory proteins were involved in kinds of enzyme, cell energy, transmission, cell recovered itself and defense mechanism et al. These results implied that processes catalyzed by these proteins probably occurred outside of cells, at least partially.

Amino Acid Sequence↗

PubMed2005

Bone mineral density and five prominent candidate genes in Chinese men: associations, interaction effects and their implications.

OBJECTIVES: Osteoporosis constitutes a serious health problem in old people. Bone mineral density (BMD) is determined by multiple genetic and environmental factors. The genetic control of BMD and osteoporosis is better understood in women, but much less in men. The present study evaluated the relationship of COL1A2, BGP, IL-6, AHSG and PTH genes defined by MspI, HindIII, BsrBI, SacI and BstBI restriction enzymes, respectively, with BMD in Chinese males. METHODS: A total of 258 unrelated healthy Chinese men aged 50-80 years were recruited. BMD at spine (L1-4) and femoral neck were measured by a Hologic 2000+ densitometer and adjusted by significant covariates of age, height and weight. All the subjects were genotyped at the upper five polymorphic sites by PCR-RFLP procedure. RESULTS: We revealed significant association of the AHSG gene with the spine BMD (P = 0.006), even after adjusting for multiple testing in our study. Carriers of 1*1 and 2*2 genotypes of AHSG gene had, respectively, approximately 5.1 and 8.1% higher spine BMD than those of 1*2 genotype. For the other four genes, no evidence of association was found (P > 0.10). No significant evidence of gene-by-gene interaction was found by two-way factorial ANOVA on the BMD variation. CONCLUSIONS: The results suggest that the AHSG gene is associated with the spine BMD in Chinese men. The present study represents the first effort to simultaneously investigate the effects of single gene locus as well as gene-by-gene interactions of multiple genes on BMD variation in Chinese men.

Age Factors↗

PubMed2005

[Frequency and distribution of variable-number tandem repeats in the genome of Aspergillus niculans].

A total of 30.1 Mb of publicly available DNA sequence in Aspergillus niculans was researched for mono- to hexanucleotide variable-number tandem repeat (VNTR) to determine its type, size and frequency. A total of 4 837 VNTRs were observed in whole genomic DNA sequence with criteria of VNTR length > 15 bp and 80% matches. Considering all six classes of VNTRs, they occur on average about once every 6.2 kb for mono- to hexanucleotide in genomic DNA. The most abundance variable-number tandem repeat is pentanucleotide repeats; the number was 1 386, followed by hexanucleotide and trinucleotide repeats, the number was 1 228 and 1 199 respectively. The least abundance is dinucleotide repeat, only 144 tracts.

Aspergillus nidulans↗

PubMed2003

Decrease of morphine-induced reward effects and withdrawal symptoms in mice overexpressing gamma-aminobutyric acid transporter I.

Morphine addiction has been shown to result from neural adaptations produced by repeated drug exposure, but the mechanism is still unclear. In the present study, we found that gamma-aminobutyric acid (GABA) uptake was increased in mouse brain 120 min after, but not 20 min after, morphine (10 mg/kg, s.c.) injection. We generated GABA transporter I (GAT1)-overexpressing mice to investigate whether the GABAergic system and GABA transporter are involved in morphine-induced reward effects and withdrawal symptoms. Our results revealed that the rewarding effects induced by morphine were significantly decreased in GAT1-overexpressing mice as measured by the conditioned place preference (CPP) paradigm. Moreover, both somatic and vegetative signs of naloxone-induced morphine withdrawal symptoms were substantially reduced in GAT1-overexpressing mice. In addition, the decreased morphine rewarding in transgenic mice could be recovered when mice were coinjected with NO-711 (a GAT1 selective inhibitor) in the CPP paradigm. These findings suggest that the GABAergic system plays an important role in morphine addiction and point to the possibility of developing drugs that target GAT1 and extend the clinical application of opiates.

Adaptation, Physiological↗

PubMed2003

Hyperalgesic effects of gamma-aminobutyric acid transporter I in mice.

The present study focused on the involvement of gamma-aminobutyric acid transporter I (GAT1) in pain. We found that GABA uptake was increased in mouse spinal cord at 20 min and 120 min after formalin injection and in mouse brain at 120 min, but not 20 min, after formalin injection. In addition, the antinociceptive effects of GAT1-selective inhibitors were examined using assays of thermal (tail-flick) and chemical (formalin and acetic acid) nociception in C57BL/6J mice. The GAT1-selective inhibitors, ethyl nipecotate and NO-711, exhibited significant antinociceptive effects in these nociceptive assays. To study further the effects of GAT1 on pain, we used two kinds of GAT1-overexpressing transgenic mice (under the control of a CMV promoter or a NSE promoter) to examine the nociceptive responses in these mice. In the thermal, formalin, and acetic acid assays, both kinds of transgenic mice displayed significant hyperalgesia after nociceptive stimuli. In addition, the micro opioid receptor antagonist naloxone had no influence on nociceptive responses in wild-type and transgenic mice. The results indicate that GAT1 is involved in the regulation of pain processes, and point to the possibility of developing analgesic drugs that target GAT1 other than opioid receptors.

Analgesics, Opioid↗

PubMed2003

Parathyroid hormone gene with bone phenotypes in Chinese.

Osteoporosis is a common disorder afflicting old people. The parathyroid hormone (PTH) gene is involved in bone remodeling and calcium homeostasis, and has been considered as an important candidate gene for osteoporosis. In this study, we simultaneously tested linkage and/or association of PTH gene with bone mineral density (BMD) and bone mineral content (BMC), two important risk factors for osteoporosis. A sample of 1263 subjects from 402 Chinese nuclear families was used. The families are composed of both parents and at least one healthy daughter aged from 20 to 45 years. All the subjects were genotyped at the polymorphic BstBI site inside the intron 2 of the PTH gene (a nucleotide substitution of G to A at the position +3244). BMD and BMC were measured at the lumbar spine and the hip region via dual-energy X-ray absorptiometry (DXA). Using QTDT (quantitative trait transmission disequilibrium test), we did not find significant results for association or linkage between the PTH gene and BMD or BMC variation at the spine or hip. Our data do not support the PTH gene as a quantitative trait locus (QTL) underlying the bone phenotypic variation in the Chinese population.

Adult↗