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J Zuo

Publications and source records attributed to J Zuo.

At least 37 records · Page 2Linked to original sources
PubMed2000

Technical advance: An estrogen receptor-based transactivator XVE mediates highly inducible gene expression in transgenic plants.

We have developed an estrogen receptor-based chemical-inducible system for use in transgenic plants. A chimeric transcription activator, XVE, was assembled by fusion of the DNA-binding domain of the bacterial repressor LexA (X), the acidic transactivating domain of VP16 (V) and the regulatory region of the human estrogen receptor (E; ER). The transactivating activity of the chimeric XVE factor, whose expression was controlled by the strong constitutive promoter G10-90, was strictly regulated by estrogens. In transgenic Arabidopsis and tobacco plants, estradiol-activated XVE can stimulate expression of a GFP reporter gene controlled by the target promoter, which consists of eight copies of the LexA operator fused upstream of the -46 35S minimal promoter. Upon induction by estradiol, GFP expression levels can be eightfold higher than that transcribed from a 35S promoter, whereas the uninduced controls have no detectable GFP transcripts, as monitored by Northern blot analysis. Neither toxic nor adverse physiological effects of the XVE system have been observed in transgenic Arabidopsis plants under all the conditions tested. The XVE system thus appears to be a reliable and efficient chemical-inducible system for regulating transgene expression in plants.

Arabidopsis↗
PubMed2000

KORRIGAN, an Arabidopsis endo-1,4-beta-glucanase, localizes to the cell plate by polarized targeting and is essential for cytokinesis.

The formation of the cell plate, a unique structure in dividing plant cells, is pivotal for cytokinesis. A mutation in the Arabidopsis KORRIGAN (KOR) gene causes the formation of aberrant cell plates, incomplete cell walls, and multinucleated cells, leading to severely abnormal seedling morphology. The mutant, designed kor1-2, was identified as a stronger allele than the previously identified kor1-1, which appears to be defective only in cell elongation. KOR1 encodes an endo-1,4-beta-d-glucanase with a transmembrane domain and two putative polarized targeting signals in the cytosolic tail. When expressed in tobacco BY2 cells, a KOR1-GFP (green fluorescence protein) fusion protein was localized to growing cell plates. Substitution mutations in the polarized targeting motifs of KOR1 caused the fusion proteins to localize to the plasma membrane as well. Expression of these mutant genes in kor1-2 plants complemented only the cell elongation defect but not the cytokinesis defect, indicating that polarized targeting of KOR1 to forming cell plates is essential for cytokinesis. Our results suggest that KOR1 plays a critical role during cytokinesis.

Amino Acid Sequence↗
PubMed2000

[grp75 protects cells from injuries caused by glucose deprivation].

To elucidate the functions of grp75, CHL cells over-expressing grp75 are cultured in glucose-free medium in order to simulate energy metabolic stress. Their susceptibilities to injuries caused by glucose deprivation are assessed by trypan blue exclusion, LDH leakage measurement and cytometry analysis. Data shows a stronger resistance to glucose deprivation among cells over-expressing grp75 than among cells constitutively expressing grp75. The outcome suggests that grp75 can protect cells from injuries caused by glucose deprivation.

Animals↗
PubMed2000

Isolation of genes related to blood glucose-control in rat skeletal muscle.

OBJECTIVE: To isolate genes related to blood glucose-control using Sprague Dawley (SD) rat skeletal muscle. METHODS: Differential gene expression between glucose stimulated and non-glucose stimulated SD rat skeletal muscle was obtained by the differential display (DD) method, Slot blotting hybridization and Northern blot hybridization. RESULTS: Several new genes that are differentially expressed in glucose stimulated and non-glucose stimulated SD rat skeletal muscle were isolated. 74 were verified by slot analysis from 181 gene tags isolated. Of them, 33 were cloned and sequenced, and homologous analysis and application for GenBank Access Number were carried out. 21 expressed sequence tag (EST) representing novel genes was confirmed by Northern blot analysis. A total of 9 novel genes showed significant differential expression patterns. CONCLUSIONS: Using improvements and modifications of the differential display technique, a labor- and cost-saving route was used to identify new genes related to blood glucose-control. We investigated differentially expressed genes at the whole body level instead of the culture cell level, to ensure experimental results closer to the normal physiological state. This technique may be valid in wide-spread application to other related research.

Animals↗
PubMed2000

[Dynamic observation and clinical significance of integrated traditional Chinese and Western medicine on interleukin-2 system, T cell and erythrocyte immune system in patients of lung cancer].

OBJECTIVE: To study the dynamic changes and its clinical significance of integrated traditional Chinese and western medicine (TCM-WM) on IL-2 system, T cell and erythrocyte immune system in patients of lung cancer. METHODS: Forty-eight cases with lung cancer were randomly divided into two groups: TCM-WM group (group I) and the chemotherapy group (group II); and 20 healthy subjects were simultaneously compared. The relevant immune indices, clinical symptoms and signs, changes of solid tumor and living quality were dynamically observed. RESULTS: (1) The serum IL-2 level of lung cancer patients were significantly lower, while sIL-2R level higher than that of the healthy subjects. And they were raised and lowered respectively after treatment, especially in the group I, but different from the control group yet. And there were highly negative correlation between IL-2 and sIL-2R levels. (2) The percentage of CD3, CD4 and the ratio CD4/CD8 were decreased markedly in both groups, except CD8 which was increased markedly. And the percentage of RBC-C3b RR was obviously lower, while that of RBC-ICR was obviously higher. But the above-mentioned indices could be improved after treatment, especially in the group I, and there were highly positive correlation between CD4/CD8 ratio and RBC-C3bRR. (3) After treatment, all above-mentioned indices were changed significantly to their corresponding opposites. However, in regard to the degree of improvement, the patients of group I were in a better position than those of group II. At the same time, improvement of their clinical symptoms and signs, change of solid tumor and living quality also showed advantageous. CONCLUSION: The therapeutic superiority of TCM-WM on lung cancer may be related with the modulation on immune function. Thus we can say that the effect of TCM-WM is better than that of chemotherapy alone.

Adenocarcinoma↗
PubMed2000

[Screening the trans-action factors binding to the enhancer element of rat GST-P by yeast one-hybrid system].

OBJECTIVE: To investigate the diversity of the mechanisms of rat glutathione S-transferase P (GST-P) gene expression regulation and the relation between rat GST-P gene expression and carcinogenesis. To search the trans-action factors binding to the enhancer element of rat GST-P (glutathione S-transferase P enhancer, GPE I). METHODS: We searched the trans-action factors binding to GPE I using yeast one-hybrid system, and analyzed the DNA sequence by sequencing and computer search. RESULTS: Two positive clones pYGPE1 and pYGPE2 were obtained. The homologies of the insert sequence of pYGPE1 nucleotide and amino acid sequences with rat c-jun cDNA were 99% and 100% respectively; the homologies of the insert sequence of pYGPE2 nucleotide and amino acid sequences with rat mitochondrial adenine nucleotide translocase cDNA were 99% and 100% respectively. CONCLUSIONS: Rat c-Jun and mitochondrial adenine nucleotide translocase can bind to the GPE I core sequence, and they perhaps are the trans-action factors of GPE I.

Animals↗
PubMed1999

Visualization of alpha9 acetylcholine receptor expression in hair cells of transgenic mice containing a modified bacterial artificial chromosome.

The alpha9 acetylcholine receptor (alpha9 AChR) is specifically expressed in hair cells of the inner ear and is believed to be involved in synaptic transmission between efferent nerves and hair cells. Using a recently developed method, we modified a bacterial artificial chromosome containing the mouse alpha9 AChR gene with a reporter gene encoding green fluorescent protein (GFP) to generate transgenic mice. GFP expression in transgenic mice recapitulated the known temporal and spatial expression of alpha9 AChR. However, we observed previously unidentified dynamic changes in alpha9 AChR expression in cochlear and vestibular sensory epithelia during neonatal development. In the cochlea, inner hair cells persistently expressed high levels of alpha9 AChR in both the apical and middle turns, whereas both outer and inner hair cells displayed dynamic changes of alpha9 AChR expression in the basal turn. In the utricle, we observed high levels of alpha9 AChR expression in the striolar region during early neonatal development and high levels of alpha9 AChR in the extrastriolar region in adult mice. Further, simultaneous visualization of efferent innervation and alpha9 AChR expression showed that dynamic expression of alpha9 AChR in developing hair cells was independent of efferent contacts. We propose that alpha9 AChR expression in developing auditory and vestibular sensory epithelia correlates with maturation of hair cells and is hair-cell autonomous.

Animals↗
PubMed1999

Mutations in a novel retina-specific gene cause autosomal dominant retinitis pigmentosa.

Inherited retinal diseases are a common cause of visual impairment in children and young adults, often resulting in severe loss of vision in later life. The most frequent form of inherited retinopathy is retinitis pigmentosa (RP), with an approximate incidence of 1 in 3,500 individuals worldwide. RP is characterized by night blindness and progressive degeneration of the midperipheral retina, accompanied by bone spicule-like pigmentary deposits and a reduced or absent electroretinogram (ERG). The disease process culminates in severe reduction of visual fields or blindness. RP is genetically heterogeneous, with autosomal dominant, autosomal recessive and X-linked forms. Here we have identified two mutations in a novel retina-specific gene from chromosome 8q that cause the RP1 form of autosomal dominant RP in three unrelated families. The protein encoded by this gene is 2,156 amino acids and its function is currently unknown, although the amino terminus has similarity to that of the doublecortin protein, whose gene (DCX) has been implicated in lissencephaly in humans. Two families have a nonsense mutation in codon 677 of this gene (Arg677stop), whereas the third family has a nonsense mutation in codon 679 (Gln679stop). In one family, two individuals homozygous for the mutant gene have more severe retinal disease compared with heterozygotes.

Adult↗
PubMed1999

Formation of glycidyl methacrylate-DNA adducts in vivo.

In in vivo test, rats were orally administrated with glycidyl methacrylate (GMA) at respective doses of 250 mg/kg, 125 mg/kg and 62.5 mg/kg, 31.25 mg/kg and solvent as control for 14 days. DNA adducts produced in the liver, kidney, blood and testis were analyzed by RP-HPLC and nuclease P1 mediated 32P-postlabelling method. Results showed that several potential GMA-DNA adducts were formed in various organs (4 adducts in blood, 3 adducts in liver and kidney, 1 adduct in testis). A linear dose-response relationship was observed within certain dose levels. The relative adduct labeling values failed to further increase any more when the concentration went up to 125 mg/kg. The order of adduct level with GMA was kidney, liver, blood and testis. The GMA adduct N3-methacrylate-2-hydroxypropyl-dCMP was found in kidney, liver and blood. These results indicated that GMA could react with negatively charged centers on DNA and form GMA-DNA adducts. If carcinogen induced DNA damage exceeds the ability of repair systems, gene mutation is induced. Therefore, study on molecular mechanism of gene mutation induced by DNA adducts is not only an important part of chemical-carcinogenesis, but also provides information on critical biomarkers for monitoring human exposure to genetic toxins.

Animals↗
PubMed1999

[HLA-DQ molecules associated with myasthenia gravis in Chinese patients].

Myasthenia Gravis (MG) is an autoimmune disease which is a neuromuscular disorder of autoimmune origin. MG in different races or ethnic groups has different genetic susceptibility. To search for the associations of MG in the Chinese patients with HLA-DQ molecules, PCR-RFLP method was employed for genotyping HLA-DQA1 and -DQB1 genes of MG patients and the normal Chinese. The distributions of alleles of DQA1 and DQB1 in the normal Chinese and the MG patients were listed. The DQB allele, DQB1 * 0302 was positively associated with MG (RR = 2.990, Pc = 0.0307), and a negative association was found for DQA1 * 0501 (RR = 0.4166, Pc = 0.0315). DQ haplotype DQA1 * 0301-DQB1 * 0302 was significantly increased in patients when compared to controls (RR = 7.727, Pc = 0.0109).

HLA-DQ Antigens↗
PubMed1999

[Role of glutathione S-transferase pi in tumor drug resistance].

OBJECTIVE: To establish the cytologic expressing system for the glutathione S-transferase pi (GST-pi) cDNA. METHODS: The pSV-GT, a recombinant plasmid containing rat GST-pi cDNA and the pSV-neo, a vector plasmid, were transfected the HeLa cells respectively and then G418 resistant colonies were isolated. The degree of the expression of GST-pi mRNA in the resultant cell lines was estimated by in situ hybridization using Digoxin-labelled probe cDNA. Cytotoxicity of variant anticancer drugs on the transfected cells were estimated by MTT assays. RESULTS: Two subclones, HeLa/pSV-GT, and HeLa/pSV-neo, which transfected respectively by pSV-GT and pSV-neo, were established. HeLa/pSV-GT expressed significantly high degree of the GST-pi mRNA, where as both the HeLa/pSV-neo and the HeLa cell lines showed the similar but negligible degree of the GST-pi mRNA expression. Moreover, HeLa/pSV-GT cells were insensitive to adriamycin, mitomycin C, and cisplatinum as compared to HeLa/pSV-neo. Concentrations of adriamycin producing 50% inhibition (IC50) to HeLa/pSV-GT was 70.13 micrograms/ml, highly elevated 6.78-fold of that of HeLa/pSV-neo, to which IC50 was 10.34 micrograms/ml.IC50 of mitomycin and cisplatinum to HeLa/pSV-GT were 10.95 and 16.52 micrograms/ml respectively, slightly but significantly higher than those to HeLa/pSV-neo, which were 7.48 and 13.70 micrograms/ml. But the cytotoxicity of vincristine on the two cell lines were not significantly different. CONCLUSIONS: These findings suggeste that HeLa/pSV-GT cell line, after being transfected with GST-pi cDNA, acquired drug-resistance property and the overexpression of GST-pi mRNA may contribute to the multidrug resistance of HeLa/pSV-GT cells. This cell line, as a stable cytogenetic system, will contribute more for the observation of GST-pi and drug resistance.

Antineoplastic Agents↗
PubMed1999

[Study on GMA-DNA adducts in vivo].

OBJECTIVE: To investigate whether glycidly mechacrylate (GMA-DNA) adducts can be produced in various organs of rat in vivo. METHODS: Rats divided into 5 groups were orally administrated with mutagen, GMA 31.25, 62.5, 125, 250 mg/kg respectively for 14 days. DNA adducts produced in liver, kidney, white blood cells and testis had been analyzed by nuclease P1 mediated 32P-postlabelling method. RESULTS: Several GMA-DNA adducts were formed in various organs (in white blood cells, 4 types, liver and kidney, 3 types and testis 1 type). The amount of GMA-DNA adducts increased with GMA dosage within 0-125 mg/kg dosages, degree of the overall level of GMA-DNA adducts in various organs were kidney > liver > white blood cells > testis. N3-methacrylate-2-hdroxypropyl-deoxycytidine monophosphate was found in kidney, liver and white blood cells. CONCLUSIONS: GMA with electrophilic group could react with negatively charged centers on DNA and form GMA-DNA adducts.

Animals↗
PubMed1998

Neuronal matrix metalloproteinase-2 degrades and inactivates a neurite-inhibiting chondroitin sulfate proteoglycan.

Chondroitin sulfate proteoglycans (CSPGs) are implicated in the regulation of axonal growth. We previously reported that the neurite-promoting activity of laminin is inhibited by association with a Schwann cell-derived CSPG and that endoneurial laminin may be inhibited by this CSPG as well [Zuo J, Hernandez YJ, Muir D (1998) Chondroitin sulfate proteoglycan with neurite-inhibiting activity is upregulated after peripheral nerve injury. J Neurobiol 34:41-54]. Mechanisms regulating axonal growth were studied by using an in vitro bioassay in which regenerating embryonic dorsal root ganglionic neurons (DRGn) were grown on sections of normal adult nerve. DRGn achieved slow neuritic growth on sections of normal nerve, which was reduced significantly by treatment with metalloproteinase inhibitors. Similar results were obtained on a synthetic substratum composed of laminin and inhibitory CSPG. DRGn expressed the matrix metalloproteinase, MMP-2, which was transported to the growth cone. Recombinant MMP-2 inactivated the neurite-inhibiting CSPG without hindering the neurite-promoting potential of laminin. Similarly, neuritic growth by DRGn cultured on normal nerve sections was increased markedly by first treating the nerve sections with MMP-2. The proteolytic deinhibition by MMP-2 was equivalent to and nonadditive with that achieved by chondroitinase, suggesting that both enzymes inactivated inhibitory CSPG. Additionally, the increases in neuritic growth resulting from treating nerve sections with MMP-2 or chondroitinase were blocked by anti-laminin antibodies. From these results we conclude that MMP-2 provides a mechanism for the deinhibition of laminin in the endoneurial basal lamina and may play an important role in the regeneration of peripheral nerve.

Animals↗
PubMed1998

Transcriptional activation of heat shock factor HSF1 probed by phosphopeptide analysis of factor 32P-labeled in vivo.

Mapping of tryptic phosphopeptides of heat shock factor 1 (HSF1) from non-stressed or moderately heat-stressed HeLa cells, labeled in vivo by [32P]orthophosphate, revealed four major phosphopeptides A to D. Heat stress drastically increased phosphopeptide signals. To identify target peptides and amino acids and to correlate phosphorylation and transactivation function, phosphopeptide maps were produced of LexA-human HSF1 chimeras and mutant derivatives thereof, and transactivation activities of original and mutant chimeras were compared. LexA-HSF1 chimeras were previously shown to be regulated identically to HSF1, except that they transactivate promoters with LexA-binding sites instead of hsp promoters. The patterns of phosphopeptides of LexA-HSF1 and endogenous HSF1 were similar. Analysis of single residue substitutions suggested that phosphopeptide C is peptide VKEEPPSPPQSPR (297-309) phosphorylated on Ser-307 but not Ser-303. Substitution of Ser-307 but not Ser-303 caused deregulation of factor activity. Mapping of several constitutively active chimeras associated unphosphorylated peptide C with the transcriptionally active HSF1 conformation, suggesting that dephosphorylation of this peptide (at Ser-307) may either be an integral step in the activation process or serve to maintain the active conformation of HSF1. Exploiting this correlation, indirect evidence was obtained that activation domains of HSF1 interact with the distantly located regulatory domain to maintain the factor in an inactive state.

Amino Acid Sequence↗
PubMed1998

A high-resolution genetic map of the nervous locus on mouse chromosome 8.

The nervous (nr) mutant mouse displays two gross recessive traits: both an exaggeration of juvenile hyperactivity and a pronounced ataxia become apparent during the third and fourth postnatal weeks. Using an intersubspecific intercross, we have established a high-resolution map of a segment of mouse chromosome 8 that places the nr locus in a genomic segment defined by D8Rck1 on the centromeric end and D8Mit3 on the telomeric end. This map position places the nr locus within the BALB/cGr congenic region of the C3HeB/ FeJ-nr strain, confirming the accuracy of our study. We used this map position to identify and evaluate three genes-ankyrin 1, cortexin, and farnesyltransferase-as candidates for the nr gene. These three genes were eliminated from consideration but allowed us to establish the conservation of synteny between the region containing the nr locus and a segment of the short arm of human chromosome 8 (8p21-p11.2). Finally, the incomplete penetrance of the nr phenotype led us to perform a screen for modifier loci, and we present evidence that such a nervous modifier locus may exist on mouse chromosome 5.

Adjuvants, Immunologic↗
PubMed1998

The human glutamate receptor delta 2 gene (GRID2) maps to chromosome 4q22.

We isolated the human glutamate receptor delta 2 (GRID2) gene, which has 97.0% identity in amino acid sequence to the mouse glutamate receptor delta 2 (Grid2) gene. We subsequently mapped this gene to human chromosome 4q22 by radiation hybrid mapping and by hybridization to two overlapping human yeast artificial chromosomes that are located in 4q22. The Grid2 gene, which is mutated in lurcher (Lc) mice, maps to mouse chromosome 6. Thus, the mapping of the GRID2 gene to human chromosome 4q22 confirms and refines a region of synteny between mouse and human genomes.

Amino Acid Sequence↗
PubMed1998

Degradation of chondroitin sulfate proteoglycan enhances the neurite-promoting potential of spinal cord tissue.

The contribution of chondroitin sulfate proteoglycan (CSPG) in the suppression of axonal growth in rat spinal cord has been examined by means of an in vitro bioassay in which regenerating neurons are grown on tissue section substrata. Dissociated embryonic chick dorsal root ganglionic neurons were grown on normal and injured adult spinal cord tissue sections treated with chondroitinases. Neuritic growth on normal spinal cord tissue was meager. However, both the percentage of neurons with neurites and the average neurite length were substantially greater on sections treated with chondroitinase ABC. Enzymes that specifically degraded dermatan sulfate or hyaluronan were ineffective. Neuritic growth was significantly greater on injured (compared to normal) spinal cord and a further dramatic increase resulted from chondroitinase ABC treatment. Neurites grew equally within white and gray matter regions after chondroitinase treatment. Observed increases in neurite outgrowth on chondroitinase-treated tissues were largely inhibited in the presence of function-blocking laminin antibodies. These findings indicate that inhibitory CSPG is widely distributed and predominant in both normal and injured spinal cord tissues. Additionally, inhibitory CSPG is implicated in negating the potential stimulatory effects of laminin that might otherwise support spinal cord regeneration.

Animals↗