Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
 
Articles by J Shi
Total Records ( 7 ) for J Shi
  P. B Mahon , J. L Payne , D. F MacKinnon , F. M Mondimore , F. S Goes , B Schweizer , D Jancic , BiGS Consortium NIMH Genetics Initiative Bipolar Disorder Consortium , P. A Holmans , J Shi , J. A Knowles , W. A Scheftner , M. M Weissman , D. F Levinson , J. R DePaulo , P. P Zandi and J. B. Potash
 

OBJECTIVE: Family studies have suggested that postpartum mood symptoms might have a partly genetic etiology. The authors used a genome-wide linkage analysis to search for chromosomal regions that harbor genetic variants conferring susceptibility for such symptoms. The authors then fine-mapped their best linkage regions, assessing single nucleotide polymorphisms (SNPs) for genetic association with postpartum symptoms. METHOD: Subjects were ascertained from two studies: the NIMH Genetics Initiative Bipolar Disorder project and the Genetics of Recurrent Early-Onset Depression. Subjects included women with a history of pregnancy, any mood disorder, and information about postpartum symptoms. In the linkage study, 1,210 women met criteria (23% with postpartum symptoms), and 417 microsatellite markers were analyzed in multipoint allele sharing analyses. For the association study, 759 women met criteria (25% with postpartum symptoms), and 16,916 SNPs in the regions of the best linkage peaks were assessed for association with postpartum symptoms. RESULTS: The maximum linkage peak for postpartum symptoms occurred on chromosome 1q21.3-q32.1, with a chromosome-wide significant likelihood ratio Z score (ZLR) of 2.93 (permutation p=0.02). This was a significant increase over the baseline ZLR of 0.32 observed at this locus among all women with a mood disorder (permutation p=0.004). Suggestive linkage was also found on 9p24.3-p22.3 (ZLR=2.91). In the fine-mapping study, the strongest implicated gene was HMCN1 (nominal p=0.00017), containing four estrogen receptor binding sites, although this was not region-wide significant. CONCLUSIONS: This is the first study to examine the genetic etiology of postpartum mood symptoms using genome-wide data. The results suggest that genetic variations on chromosomes 1q21.3-q32.1 and 9p24.3-p22.3 may increase susceptibility to postpartum mood symptoms.

  A. R Sanders , D. F Levinson , J Duan , J. M Dennis , R Li , K. S Kendler , J. P Rice , J Shi , B. J Mowry , F Amin , J. M Silverman , N. G Buccola , W. F Byerley , D. W Black , R Freedman , C. R Cloninger and P. V. Gejman
  Objective

The Molecular Genetics of Schizophrenia (MGS2) project recruited an adult control sample of non-Hispanic European-ancestry (N=3,364) and African American (N=1,301) subjects.

Method

Subjects gave consent to deposit phenotypic data and blood samples into a repository for general research use, with full anonymization of the sample. The authors compared the control sample with population census data for demographic data and with previous population surveys for anthropometrics and prevalences of psychiatric disorders as estimated by an Internet-administered questionnaire.

Results

The full MGS2 control sample includes 4,665 subjects (European-ancestry: N=3,364; African American: N=1,301), of whom 3,626 were included in the MGS2 genome-wide association study (GWAS). The sample is generally demographically representative of the U.S. population, except for being older and more female, educated, and affluent, although all strata are represented. Self-reported ancestry was consistent with genotypic and census data. Lifetime prevalences for depressive, anxiety, and substance use diagnoses were higher than in previous population-based surveys, probably due to use of an abbreviated self-report instrument. However, patterns such as sex ratios, comorbidity, and demographic associations were consistent with previous reports. DNA quality for the Internet collected/evaluated control sample was comparable to that of the face-to-face case sample.

Conclusions

The Internet-based methods facilitated the rapid collection of large and anonymized non-Hispanic European-ancestry and African American control samples that have been validated as being generally representative for many aspects of demography, ancestry, and morbidity. Utilization of clinical screening data shared with the scientific community may permit investigators to select appropriate controls for some studies.

  C. M Lewis , M. Y Ng , A. W Butler , S Cohen Woods , R Uher , K Pirlo , M. E Weale , A Schosser , U. M Paredes , M Rivera , N Craddock , M. J Owen , L Jones , I Jones , A Korszun , K. J Aitchison , J Shi , J. P Quinn , A MacKenzie , P Vollenweider , G Waeber , S Heath , M Lathrop , P Muglia , M. R Barnes , J. C Whittaker , F Tozzi , F Holsboer , M Preisig , A. E Farmer , G Breen , I. W Craig and P. McGuffin
  Objective

Studies of major depression in twins and families have shown moderate to high heritability, but extensive molecular studies have failed to identify susceptibility genes convincingly. To detect genetic variants contributing to major depression, the authors performed a genome-wide association study using 1,636 cases of depression ascertained in the U.K. and 1,594 comparison subjects screened negative for psychiatric disorders.

Method

Cases were collected from 1) a case-control study of recurrent depression (the Depression Case Control [DeCC] study; N=1346), 2) an affected sibling pair linkage study of recurrent depression (probands from the Depression Network [DeNT] study; N=332), and 3) a pharmacogenetic study (the Genome-Based Therapeutic Drugs for Depression [GENDEP] study; N=88). Depression cases and comparison subjects were genotyped at Centre National de Génotypage on the Illumina Human610-Quad BeadChip. After applying stringent quality control criteria for missing genotypes, departure from Hardy-Weinberg equilibrium, and low minor allele frequency, the authors tested for association to depression using logistic regression, correcting for population ancestry.

Results

Single nucleotide polymorphisms (SNPs) in BICC1 achieved suggestive evidence for association, which strengthened after imputation of ungenotyped markers, and in analysis of female depression cases. A meta-analysis of U.K. data with previously published results from studies in Munich and Lausanne showed some evidence for association near neuroligin 1 (NLGN1) on chromosome 3, but did not support findings at BICC1.

Conclusions

This study identifies several signals for association worthy of further investigation but, as in previous genome-wide studies, suggests that individual gene contributions to depression are likely to have only minor effects, and very large pooled analyses will be required to identify them.

  F Liu , J Shi , H Tanimukai , J Gu , I Grundke Iqbal , K Iqbal and C. X. Gong
 

It has been established for a long time that brain glucose metabolism is impaired in Alzheimer's disease. Recent studies have demonstrated that impaired brain glucose metabolism precedes the appearance of clinical symptoms, implying its active role in the development of Alzheimer's disease. However, the molecular mechanism by which this impairment contributes to the disease is not known. In this study, we demonstrated that protein O-GlcNAcylation, a common post-translational modification of nucleocytoplasmic proteins with β-N-acetyl-glucosamine and a process regulated by glucose metabolism, was markedly decreased in Alzheimer's disease cerebrum. More importantly, the decrease in O-GlcNAc correlated negatively with phosphorylation at most phosphorylation sites of tau protein, which is known to play a crucial role in the neurofibrillary degeneration of Alzheimer's disease. We also found that hyperphosphorylated tau contained 4-fold less O-GlcNAc than non-hyperphosphorylated tau, demonstrating for the first time an inverse relationship between O-GlcNAcylation and phosphorylation of tau in the human brain. Downregulation of O-GlcNAcylation by knockdown of O-GlcNAc transferase with small hairpin RNA led to increased phosphorylation of tau in HEK-293 cells. Inhibition of the hexosamine biosynthesis pathway in rat brain resulted in decreased O-GlcNAcylation and increased phosphorylation of tau, which resembled changes of O-GlcNAcylation and phosphorylation of tau in rodent brains with decreased glucose metabolism induced by fasting, but not those in rat brains when protein phosphatase 2A was inhibited. Comparison of tau phosphorylation patterns under various conditions suggests that abnormal tau hyperphosphorylation in Alzheimer's disease brain may result from downregulation of both O-GlcNAcylation and protein phosphatase 2A. These findings suggest that impaired brain glucose metabolism leads to abnormal hyperphosphorylation of tau and neurofibrillary degeneration via downregulation of tau O-GlcNAcylation in Alzheimer's disease. Thus, restoration of brain tau O-GlcNAcylation and protein phosphatase 2A activity may offer promising therapeutic targets for treating Alzheimer's disease.

  R Inoue , L. J Jensen , Z Jian , J Shi , L Hai , A. I Lurie , F. H Henriksen , M Salomonsson , H Morita , Y Kawarabayashi , M Mori , Y Mori and Y. Ito
 

TRPC6 is a non–voltage-gated Ca2+ entry/depolarization channel associated with vascular tone regulation and remodeling. Expressed TRPC6 channel responds to both neurohormonal and mechanical stimuli, the mechanism for which remains controversial. In this study, we examined the possible interactions of receptor and mechanical stimulations in activating this channel using the patch clamp technique. In HEK293 cells expressing TRPC6, application of mechanical stimuli (hypotonicity, shear, 2,4,6-trinitrophenol) caused, albeit not effective by themselves, a prominent potentiation of cationic currents (ITRPC6) induced by a muscarinic receptor agonist carbachol. This effect was insensitive to a tarantula toxin GsMTx-4 (5 µmol/L). A similar extent of mechanical potentiation was observed after activation of ITRPC6 by GTPS or a diacylglycerol analog 1-oleoyl-2-acetyl-sn-glycerol (OAG). Single TRPC6 channel activity evoked by carbachol was also enhanced by a negative pressure added in the patch pipette. Mechanical potentiation of carbachol- or OAG-induced ITRPC6 was abolished by small interfering RNA knockdown of cytosolic phospholipase A2 or pharmacological inhibition of -hydroxylation of arachidonic acid into 20-HETE (20-hydroxyeicosatetraenoic acid). Conversely, direct application of 20-HETE enhanced both OAG-induced macroscopic and single channel TRPC6 currents. Essentially the same results were obtained for TRPC6-like cation channel in A7r5 myocytes, where its activation by noradrenaline or Arg8 vasopressin was greatly enhanced by mechanical stimuli via 20-HETE production. Furthermore, myogenic response of pressurized mesenteric artery was significantly enhanced by weak receptor stimulation dependently on 20-HETE production. These results collectively suggest that simultaneous operation of receptor and mechanical stimulations may synergistically amplify transmembrane Ca2+ mobilization through TRPC6 activation, thereby enhancing the vascular tone via phospholipase C/diacylglycerol and phospholipase A2/-hydroxylase/20-HETE pathways.

  J Shi , R Bezabhie and A. Szkudlinska
 

The in vitro micronucleus (MN) assay is widely used to assess genotoxic potential of the test substances by measuring frequency of MN in cultured mammalian cells. Traditionally, MN frequency has been determined by microscopy. In recent years, a flow cytometric method for enumeration of MN has been developed, which significantly shortens analysis time and enhances assay throughput. However, a major concern has been raised that the MN results obtained from flow cytometry can be impacted by chromatin bodies produced during apoptosis or necrosis. In this work, we further evaluated this flow cytometry-based in vitro MN assay with CHO-K1 cells in a 24-well platform. Our results showed that the MN frequency determined using the flow cytometric method was highly correlated with the microscopy results. Importantly, several non-genotoxic apoptosis inducers or cytotoxins that have been previously reported to produce ‘artificial positives’ in various in vitro genotoxicity tests were evaluated in this system. As a result, these non-genotoxic cytotoxins did not produce false-positive MN response in the flow cytometric system in CHO-K1 cells when cytotoxicity was <50 ± 10%. Moreover, a total of 21 compounds were evaluated in this work, including direct or indirect clastogens, aneugens and non-genotoxic chemicals. A sensitivity of 83.3% and a specificity of 100% were obtained from the compounds we tested. Finally, significant increase of incidents in the hypodiploid region, an aneugenic signature, was confirmed in our evaluation. In conclusion, the flow cytometric in vitro MN assay is a reliable method that can be used to detect clastogenic or aneugenic potential of the test substances in CHO-K1 cells.

  W. A Dunnick , J. T Collins , J Shi , G Westfield , C Fontaine , P Hakimpour and F. N. Papavasiliou
 

Both class switch recombination (CSR) and somatic hypermutation (SHM) require transcription and the trans-acting factor activation-induced cytidine deaminase (AID), and must be up-regulated during antigen-dependent differentiation of B lymphocytes. To test the role of the heavy chain 3' enhancers in both CSR and SHM, we used a BAC transgene of the entire heavy chain constant region locus. Using Cre-loxP recombination to delete a 28-kb region that contains the four known 3' heavy chain enhancers, we isolated lines of BAC transgenic mice with an intact heavy chain locus and paired lines in the same chromosomal insertion site lacking the 3' enhancers. Intact heavy chain transgenes undergo CSR to all heavy chain genes and mutate their transgenic VDJ exon. In paired transgenes lacking the 3' enhancer region, CSR to most heavy chain genes is reduced to ~1% of the levels for intact heavy chain loci; SHM is also reduced. Finally, we find that in B cells with a transgene lacking the 3' enhancers, interchromosomal recombination between the transgenic VDJ exon and the endogenous heavy chain C genes is more easily detected than CSR within the transgene.

 
 
 
Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility