43 results on '"Lei, Lei"'
Search Results
2. Analysis on single nucleotide polymorphisms of the PeTPS-(-)Apin gene in Pinus elliottii.
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Lei, Lei, Zhang, Lu, Cai, Junhuo, Yi, Min, Zhao, Heng, Ma, Jikai, Lai, Meng, and Jin, Cangfu
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SINGLE nucleotide polymorphisms , *SLASH pine , *GENETIC variation , *MOLECULAR cloning , *SLASH (Logging) - Abstract
Background: Resin-tapping forests of slash pine (Pinus elliottii) have been set up across Southern China owing to their high production and good resin quality, which has led to the rapid growth of the resin industry. In this study, we aimed to identify molecular markers associated with resin traits in pine trees, which may help develop marker-assisted selection (MAS). Methods: PeTPS-(-)Apin gene was cloned by double primers (external and internal). DnaSP V4.0 software was used to evaluate genetic diversity and linkage disequilibrium. SHEsis was used for haplotype analysis. SPSS was used for ANOVA and χ2 test. DnaSP v4.0 software was used to evaluate genetic diversity. Results: The full length PeTPS-(-)Apin gene was characterized and shown to have 4638 bp, coding for a 629-amino acid protein. A total of 72 single nucleotide polymorphism (SNP) loci were found. Three SNPs (CG615, AT641 and AG3859) were significantly correlated with α -pinene content, with a contribution rate > 10%. These SNPs were used to select P. elliottii with high α-pinene content, and a 118.0% realistic gain was obtained. Conclusions: The PeTPS-(-)Apin gene is not uniquely decisive for selection of plus slash pines with stable production, high yield, and good quality, but it can be used as a reference for selection of other resin-producing pines and other resin components. [ABSTRACT FROM AUTHOR]
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- 2022
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3. The draft mitochondrial genome of Magnolia biondii and mitochondrial phylogenomics of angiosperms
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Yang Liu, Zhang Suzhou, Lei-Lei Yang, Shouzhou Zhang, Xiaoan Lang, Yaling Wang, Shan-Shan Dong, and Lu Chen
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0106 biological sciences ,0301 basic medicine ,Plant Science ,Plant Genetics ,01 natural sciences ,Genome ,Biochemistry ,Phylogenomics ,Nymphaea ,Plant Genomics ,Plastids ,Genome Evolution ,Flowering Plants ,Energy-Producing Organelles ,Conserved Sequence ,Phylogeny ,Data Management ,Multidisciplinary ,food and beverages ,Eukaryota ,Phylogenetic Analysis ,Genomics ,Plants ,Mitochondria ,Phylogenetics ,Medicine ,Engineering and Technology ,Cellular Structures and Organelles ,Genome, Plant ,Research Article ,Biotechnology ,Mitochondrial DNA ,Computer and Information Sciences ,Nuclear gene ,Liriodendron ,Science ,Plant Cell Biology ,Bioengineering ,Biology ,Bioenergetics ,Genes, Plant ,Molecular Evolution ,03 medical and health sciences ,Magnoliopsida ,Genetics ,Evolutionary Systematics ,Gene ,Genome size ,Taxonomy ,Evolutionary Biology ,Organisms ,Biology and Life Sciences ,Computational Biology ,Molecular Sequence Annotation ,Cell Biology ,Genome Analysis ,030104 developmental biology ,Evolutionary biology ,Magnolia ,Genome, Mitochondrial ,Plant Biotechnology ,GC-content ,010606 plant biology & botany - Abstract
The mitochondrial genomes of flowering plants are well known for their large size, variable coding-gene set and fluid genome structure. The available mitochondrial genomes of the early angiosperms show extreme genetic diversity in genome size, structure, and sequences, such as rampant HGTs in Amborella mt genome, numerous repeated sequences in Nymphaea mt genome, and conserved gene evolution in Liriodendron mt genome. However, currently available early angiosperm mt genomes are still limited, hampering us from obtaining an overall picture of the mitogenomic evolution in angiosperms. Here we sequenced and assembled the draft mitochondrial genome of Magnolia biondii Pamp. from Magnoliaceae (magnoliids) using Oxford Nanopore sequencing technology. We recovered a single linear mitochondrial contig of 967,100 bp with an average read coverage of 122 × and a GC content of 46.6%. This draft mitochondrial genome contains a rich 64-gene set, similar to those of Liriodendron and Nymphaea, including 41 protein-coding genes, 20 tRNAs, and 3 rRNAs. Twenty cis-spliced and five trans-spliced introns break ten protein-coding genes in the Magnolia mt genome. Repeated sequences account for 27% of the draft genome, with 17 out of the 1,145 repeats showing recombination evidence. Although partially assembled, the approximately 1-Mb mt genome of Magnolia is still among the largest in angiosperms, which is possibly due to the expansion of repeated sequences, retention of ancestral mtDNAs, and the incorporation of nuclear genome sequences. Mitochondrial phylogenomic analysis of the concatenated datasets of 38 conserved protein-coding genes from 91 representatives of angiosperm species supports the sister relationship of magnoliids with monocots and eudicots, which is congruent with plastid evidence.
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- 2020
4. Prediction of potential prognostic biomarkers in metastatic prostate cancer based on a circular RNA-mediated competing endogenous RNA regulatory network.
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Luo, Liang, Zhang, Lei-Lei, Tao, Wen, Xia, Tao-Lin, and Li, Liao-Yuan
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PROGNOSIS , *CIRCULAR RNA , *PROSTATE cancer , *METASTASIS , *RNA , *PROGRESSION-free survival - Abstract
Recently, studies on competing endogenous RNA (ceRNA) networks have become prevalent, and circular RNAs (circRNAs) have crucial implications for the development and progression of carcinoma. However, studies relevant to metastatic prostate cancer (mPCa) are scant. This study aims to discover potential ceRNAs that may be related to the prognosis of mPCa. RNA-Seq data were obtained from the MiOncoCirc database and Gene Expression Omnibus (GEO). Differential expression patterns of RNAs were examined using R packages. Circular RNA Interactome, miRTarBase, miRDB and TargetScan were applied to predict the corresponding relation between circRNAs, miRNAs and mRNAs. The Gene Ontology (GO) annotations were performed to present related GO terms, and Gene Set Enrichment Analysis (GSEA) tools were applied for pathway annotations. Moreover, survival analysis was conducted for the hub genes. We found 820 circRNAs, 81 miRNAs and 179 mRNAs that were distinguishingly expressed between primary prostate cancer (PCa) and mPCa samples. A ceRNA network including 45 circRNAs, 24 miRNAs and 56 mRNAs was constructed. In addition, the protein–protein interaction (PPI) network was built, and 10 hub genes were selected by using the CytoHubba application. Among the 10 hub genes, survival analysis showed that ITGA1, LMOD1, MYH11, MYLK, SORBS1 and TGFBR3 were significantly connected with disease-free survival (DFS). The circRNA-mediated ceRNA network provides potential prognostic biomarkers for metastatic prostate cancer. [ABSTRACT FROM AUTHOR]
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- 2021
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5. Circulating Betatrophin Levels and Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis
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Ge Li, Jia-Qiang Zhou, Lei-Lei Ma, Fei-Juan Kong, and Yi-Xin Chen
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Betatrophin ,Physiology ,Maternal Health ,lcsh:Medicine ,Cochrane Library ,Body Mass Index ,Database and Informatics Methods ,0302 clinical medicine ,Mathematical and Statistical Techniques ,Endocrinology ,Pregnancy ,Medicine and Health Sciences ,Enzyme-Linked Immunoassays ,Database Searching ,lcsh:Science ,Multidisciplinary ,Obstetrics ,Obstetrics and Gynecology ,Gestational diabetes ,Physiological Parameters ,030220 oncology & carcinogenesis ,Meta-analysis ,Physical Sciences ,Statistics (Mathematics) ,Research Article ,medicine.medical_specialty ,Endocrine Disorders ,030209 endocrinology & metabolism ,Research and Analysis Methods ,03 medical and health sciences ,Insulin resistance ,Diabetes mellitus ,medicine ,Diabetes Mellitus ,Obesity ,Statistical Methods ,Gestational Diabetes ,Immunoassays ,business.industry ,lcsh:R ,Body Weight ,nutritional and metabolic diseases ,Biology and Life Sciences ,medicine.disease ,Metabolic Disorders ,Immunologic Techniques ,Women's Health ,lcsh:Q ,business ,Body mass index ,Mathematics ,Meta-Analysis - Abstract
Objective The association between circulating betatrophin levels and gestational diabetes mellitus (GDM) is controversial. The aim of our study was to systematically review available literature linking betatrophin to GDM for a comprehensive understanding of the relationship between circulating betatrophin levels and GDM in human. Methods PubMed, The Cochrane Library, Medline and CNKI were searched for studies published up to August 2016. Manual searches of references of the relevant original studies were conducted. Pooled estimates were measured using the fixed or random effect model. Overall effect was reported in a standard mean difference (SMD). All data were analyzed with Review Manager 5.3 and Stata 12.0. Results Of 25 references reviewed, 8 studies met our inclusion criteria and contributed to meta-analysis. All the studies were used to evaluate the relationship between betatrophin levels in blood and GDM. Betatrophin levels were significantly elevated in women with GDM compared with those without GDM (SMD = 1.05; 95% CI: 0.41–1.68, P = 0.001). This evidence was more consistent among women with betatrophin blood draw during the third trimester (SMD = 1.3, 95% CI: 1–1.61, P < 0.001) and for women BMI ≥ 28 kg/m2 (SMD = 1.53, 95% CI: 1.30–1.75, P < 0.001). Conclusions The evidences from this meta-analysis indicated that the levels of circulating betatrophin were significantly elevated among women with GDM compared with women with normal glucose tolerance, especially with BMI ≥ 28 kg/m2 and in the third trimester.
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- 2017
6. Acetobixan, an Inhibitor of Cellulose Synthesis Identified by Microbial Bioprospecting
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Ian S. Wallace, Seth DeBolt, Ye Xia, Chad Brabham, Adam Ladak, James R. Strickland, Jozsef Stork, Ying Gu, and Lei Lei
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0106 biological sciences ,Agricultural Biotechnology ,Mutant ,lcsh:Medicine ,Plant Science ,Biology ,01 natural sciences ,Microbiology ,Mass Spectrometry ,03 medical and health sciences ,chemistry.chemical_compound ,Biosynthesis ,Arabidopsis ,RNA, Ribosomal, 16S ,Acetamides ,Genetics ,Arabidopsis thaliana ,Secretion ,Cellulose ,lcsh:Science ,030304 developmental biology ,DNA Primers ,0303 health sciences ,Multidisciplinary ,Microscopy, Confocal ,Base Sequence ,lcsh:R ,Ecology and Environmental Sciences ,Biology and Life Sciences ,Agriculture ,biology.organism_classification ,Biochemistry ,chemistry ,lcsh:Q ,Pharmacophore ,Agrochemicals ,Cortical microtubule ,010606 plant biology & botany ,Research Article ,Biotechnology ,Chromatography, Liquid - Abstract
In plants, cellulose biosynthesis is an essential process for anisotropic growth and therefore is an ideal target for inhibition. Based on the documented utility of small-molecule inhibitors to dissect complex cellular processes we identified a cellulose biosynthesis inhibitor (CBI), named acetobixan, by bio-prospecting among compounds secreted by endophytic microorganisms. Acetobixan was identified using a drug-gene interaction screen to sift through hundreds of endophytic microbial secretions for one that caused synergistic reduction in root expansion of the leaky AtcesA6prc1-1 mutant. We then mined this microbial secretion for compounds that were differentially abundant compared with Bacilli that failed to mimic CBI action to isolate a lead pharmacophore. Analogs of this lead compound were screened for CBI activity, and the most potent analog was named acetobixan. In living Arabidopsis cells visualized by confocal microscopy, acetobixan treatment caused CESA particles localized at the plasma membrane (PM) to rapidly re-localize to cytoplasmic vesicles. Acetobixan inhibited 14C-Glc uptake into crystalline cellulose. Moreover, cortical microtubule dynamics were not disrupted by acetobixan, suggesting specific activity towards cellulose synthesis. Previous CBI resistant mutants such as ixr1-2, ixr2-1 or aegeus were not cross resistant to acetobixan indicating that acetobixan targets a different aspect of cellulose biosynthesis.
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- 2014
7. Oviduct Infection and Hydrosalpinx in DBA1/j Mice Is Induced by Intracervical but Not Intravaginal Inoculation with Chlamydia muridarum
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Lingli Tang, Siqi Gong, Hongbo Zhang, Zhiguang Zhou, Lei Lei, Joel B. Baseman, and Guangming Zhong
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Chlamydia muridarum ,animal structures ,Uterus ,lcsh:Medicine ,Cervix Uteri ,Biology ,medicine.disease_cause ,Reproductive Tract Infections ,Pathogenesis ,Andrology ,03 medical and health sciences ,Mice ,medicine ,Animals ,Humans ,lcsh:Science ,Hydrosalpinx ,Fallopian Tubes ,030304 developmental biology ,0303 health sciences ,Multidisciplinary ,Chlamydia ,030306 microbiology ,lcsh:R ,Chlamydia Infections ,Fallopian Tube Diseases ,biology.organism_classification ,medicine.disease ,3. Good health ,Mice, Inbred C57BL ,Disease Models, Animal ,medicine.anatomical_structure ,Mice, Inbred DBA ,Immunology ,Vagina ,Oviduct ,lcsh:Q ,Female ,Chlamydia trachomatis ,Research Article ,HeLa Cells - Abstract
Intravaginal infection with C. muridarum in mice often results in hydrosalpinx similar to that found in women urogenitally infected with C. trachomatis, making the C. muridarum lower genital tract infection murine model suitable for studying C. trachomatis pathogenesis. To our surprise, DBA1/j mice were highly resistant to hydrosalpinx following an intravaginal infection with C. muridarum although these mice were as susceptible to lower genital tract infection as other mouse strains. A significantly lower level of C. muridarum organisms was recovered from the oviduct of DBA1/j mice, correlating the resistance to hydrosalpinx with reduced ascension of C. muridarum to the oviduct. The DBA1/j resistance to hydrosalpinx was effectively overcome by intracervical inoculation with C. muridarum. The intracervically inoculated DBA1/j mice developed severe hydrosalpinx with the highest levels of live C. muridarum organisms recovered from uterine tissue on day 3 and oviduct tissue on day 7 post inoculation while in intravaginally inoculated DBA1/j mice, the peak of live organism recovery from uterine tissue was delayed to day 7 with no rise in the amount of live organisms recovered from the oviduct. These observations have not only validated the correlation between hydrosalpinx and live organism invasion in the oviduct but also demonstrated that the intracervical inoculation, by promoting rapid chlamydial replication in the uterine epithelial cells and ascension to the oviduct of DBA1/j mice, may be used for further understanding chlamydial pathogenic mechanisms. The above findings also suggest that strategies aimed at reducing tubal infection may be most effective in blocking tubal pathology.
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- 2013
8. Chlamydia trachomatis GlgA Is Secreted into Host Cell Cytoplasm
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Yimou Wu, Bo Peng, Guangming Zhong, Lingli Tang, Honglei Ding, Chunxue Lu, Siqi Gong, Lei Lei, and Zhongyu Li
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Blotting, Western ,lcsh:Medicine ,Fluorescent Antibody Technique ,Chlamydia trachomatis ,Enzyme-Linked Immunosorbent Assay ,medicine.disease_cause ,Microbiology ,03 medical and health sciences ,Bacterial Proteins ,medicine ,Humans ,Secretion ,lcsh:Science ,Glycogen synthase ,030304 developmental biology ,0303 health sciences ,Multidisciplinary ,Chlamydia ,Host cell cytosol ,biology ,030306 microbiology ,lcsh:R ,medicine.disease ,Fusion protein ,Molecular biology ,3. Good health ,Cytosol ,Glycogen Synthase ,Host cell cytoplasm ,biology.protein ,lcsh:Q ,Glycogen ,Research Article ,HeLa Cells - Abstract
Glycogen has been localized both inside and outside Chlamydia trachomatis organisms. We now report that C. trachomatis glycogen synthase (GlgA) was detected in both chlamydial organism-associated and -free forms. The organism-free GlgA molecules were localized both in the lumen of chlamydial inclusions and in the cytosol of host cells. The cytosolic GlgA displayed a distribution pattern similar to that of a known C. trachomatis-secreted protease, CPAF. The detection of GlgA was specific since the anti-GlgA antibody labeling was only removed by preabsorption with GlgA but not CPAF fusion proteins. GlgA was detectable at 12h and its localization into host cell cytosol only became apparent at 24h after infection. The cytosolic localization of GlgA was conserved among all C. trachomatis serovars. However, the significance of the GlgA secretion into host cell cytoplasm remains unclear since, while expression of chlamydial GlgA in HeLa cells increased glycogen stores, it did not affect a subsequent infection with C. trachomatis. Similar to several other C. trachomatis-secreted proteins, GlgA is immunogenic in women urogenitally infected with C. trachomatis, suggesting that GlgA is expressed and may be secreted into host cell cytosol during C. trachomatis infection in humans. These findings have provided important information for further understanding C. trachomatis pathogenic mechanisms.
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- 2013
9. Identification of a Novel Nuclear Localization Signal Sequence in Chlamydia trachomatis-Secreted Hypothetical Protein CT311
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Xiaohua Dong, Guangming Zhong, Lei Lei, and Zhongyu Li
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Nuclear Localization Signals ,lcsh:Medicine ,Chlamydia trachomatis ,medicine.disease_cause ,Biochemistry ,Molecular Cell Biology ,Gram Negative ,Chlamydia ,lcsh:Science ,Peptide sequence ,Host cell nucleus ,0303 health sciences ,Multidisciplinary ,Host cell cytosol ,Obstetrics and Gynecology ,Cellular Structures ,3. Good health ,Cell biology ,Bacterial Pathogens ,medicine.anatomical_structure ,Infectious Diseases ,Host-Pathogen Interactions ,Medicine ,Research Article ,Urology ,Hypothetical protein ,Molecular Sequence Data ,Sexually Transmitted Diseases ,Active Transport, Cell Nucleus ,Biology ,Microbiology ,Peptide Mapping ,03 medical and health sciences ,Bacterial Proteins ,medicine ,Humans ,Amino Acid Sequence ,030304 developmental biology ,Cell Nucleus ,030306 microbiology ,Genitourinary Infections ,lcsh:R ,Proteins ,Virology ,Cytosol ,Cell nucleus ,lcsh:Q ,Nuclear localization sequence ,HeLa Cells - Abstract
We previously reported that Chlamydia trachomatis hypothetical protein CT311 was secreted out of chlamydial inclusion and into host cell cytosol. We now found that CT311 further entered host cell nucleus at the late stage of infection and continued to accumulate in the nucleus of C. trachomatis-infected cells. When CT311 was expressed via a transgene in mammalian cells, CT311 protein was exclusively detected in the nucleus, suggesting that CT311 by itself is sufficient for nuclear targeting. However, preexisting nuclear CT311 did not affect subsequent chlamydial infection. Using deletion constructs, we mapped a nuclear localization signal sequence of CT311 to residues 21 to 63 ((21)AVEGKPLSRAAQLRERRKDLHVSGKPSPRYALKKRALEAKKNK(63)). This sequence was sufficient for targeting a heterologous protein into mammalian cell nucleus and it contains two independent clusters of basic residues ((34)RERRK(38) and (53)KKRALEAKKNK(63) respectively). Deletion or alanine substitution of the basic residues in either cluster led to loss of nuclear targeting activity, suggesting that both clusters are critical for the nuclear targeting function. These observations have demonstrated that the hypothetical protein CT311 possesses a novel nuclear localization signal sequence with dual modules of basic residues for targeting host cell nucleus during Chlamydia trachomatis infection.
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- 2013
10. Distinct Translational Control in CD4+ T Cell Subsets
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Carston R. Wagner, Ola Larsson, Ekaterina Yurchenko, Valentina Gandin, Ivan Topisirovic, Lei-Lei Zheng, Nahum Sonenberg, Ciriaco A. Piccirillo, Shui-jun Li, and Eva Bjur
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CD4-Positive T-Lymphocytes ,Cancer Research ,lcsh:QH426-470 ,Cellular differentiation ,T cell ,Eukaryotic Initiation Factor-4E ,Immunology ,chemical and pharmacologic phenomena ,Biology ,T-Lymphocytes, Regulatory ,03 medical and health sciences ,0302 clinical medicine ,T-Lymphocyte Subsets ,medicine ,Genetics ,Immune Tolerance ,Humans ,RNA, Messenger ,Molecular Biology ,Genetics (clinical) ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,0303 health sciences ,Cell growth ,EIF4E ,FOXP3 ,Translation (biology) ,Forkhead Transcription Factors ,Cell cycle ,Molecular biology ,3. Good health ,Cell biology ,lcsh:Genetics ,medicine.anatomical_structure ,Gene Expression Regulation ,030220 oncology & carcinogenesis ,Research Article - Abstract
Regulatory T cells expressing the transcription factor Foxp3 play indispensable roles for the induction and maintenance of immunological self-tolerance and immune homeostasis. Genome-wide mRNA expression studies have defined canonical signatures of T cell subsets. Changes in steady-state mRNA levels, however, often do not reflect those of corresponding proteins due to post-transcriptional mechanisms including mRNA translation. Here, we unveil a unique translational signature, contrasting CD4+Foxp3+ regulatory T (TFoxp3+) and CD4+Foxp3− non-regulatory T (TFoxp3−) cells, which imprints subset-specific protein expression. We further show that translation of eukaryotic translation initiation factor 4E (eIF4E) is induced during T cell activation and, in turn, regulates translation of cell cycle related mRNAs and proliferation in both TFoxp3− and TFoxp3+ cells. Unexpectedly, eIF4E also affects Foxp3 expression and thereby lineage identity. Thus, mRNA–specific translational control directs both common and distinct cellular processes in CD4+ T cell subsets., Author Summary Regulatory T cells expressing the nuclear protein Foxp3 are essential for the control of immune responses towards self and foreign antigens. Genome-wide gene expression studies have defined canonical signatures of T cell subsets. However, changes in mRNA levels often do not reflect those of corresponding proteins due to post-transcriptional mechanisms including mRNA translation. In Bjur et al., we discovered a unique translational signature, which distinguishes immunosuppressive Foxp3+ regulatory T from inflammatory Foxp3− T cells and establishes proteomes and functions in T cell subsets. We also show that cell activation or growth factors increase the translation of eukaryotic translation initiation factor 4E (eIF4E), which induces proliferation in both T cell subsets. Unexpectedly, eIF4E also affects Foxp3 expression and can drive lineage identity. Thus, distinct translational control directs both common and distinct cellular processes in CD4+ T cell subsets.
- Published
- 2013
11. Integrated analysis of transcriptome and proteome changes related to the Ogura cytoplasmic male sterility in cabbage.
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Xing, Miaomiao, Sun, Chao, Li, Hailong, Hu, Shilin, Lei, Lei, and Kang, Jungen
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CABBAGE ,STERILITY in plants ,PROTEOMICS ,SPOROPOLLENIN ,CELL death - Abstract
Cabbage (Brassica oleracea L. var. capitata), an important vegetable crop in the Brassicaceae family, is economically important worldwide. In the process of hybrid seed production, Ogura cytoplasmic male sterility (OguCMS), controlled by the mitochondrial gene orf138, has been extensively used for cabbage hybrid production with complete and stable male sterility. To identify the critical genes and pathways involved in the sterility and to better understand the underlying molecular mechanisms, the anther of OguCMS line R2P2CMS and the fertile line R2P2 were used for RNA-seq and iTRAQ (Isobaric Tags for Relative and Absolute Quantitation) proteome analysis. RNA-seq analysis generated 13,037,109 to 13,066,594 SE50-clean reads, from the sterile and fertile lines, which were assembled into 36,890 unigenes. Among them, 1,323 differentially expressed genes (DEGs) were identified, consisting of 307 up- and 1016 down-regulated genes. For ITRAQ analysis, a total of 7,147 unique proteins were identified, and 833 were differentially expressed including 538 up- and 295 down-regulated proteins. These were mainly annotated to the ribosome, spliceosome and mRNA surveillance pathways. Combined transcriptomic and proteomic analyses identified 22 and 70 genes with the same and opposite expression profiles, respectively. Using KEGG analysis of DEGs, gibberellin mediated signaling pathways regulating tapetum programmed cell death and four different pathways involved in sporopollenin synthesis were identified. Secretion and translocation of the sporopollenin precursors were identified, and the key genes participating in these pathways were all significantly down-regulated in R2P2CMS. Light and transmission electron (TE) microscopy revealed fat abnormal tapetum rather than vacuolization and degradation at the tetrad and microspore stages of the OguCMS line. This resulted in the failed deposition of sporopollenin on the pollen resulting in sterility. This study provides a comprehensive understanding of the mechanism underlying OguCMS in cabbage. [ABSTRACT FROM AUTHOR]
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- 2018
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12. DNA methylation mediates the effect of maternal cognitive appraisal of a disaster in pregnancy on the child’s C-peptide secretion in adolescence: Project Ice Storm.
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Cao-Lei, Lei, Dancause, Kelsey N., Elgbeili, Guillaume, Laplante, David P., Szyf, Moshe, and King, Suzanne
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DNA methylation , *METHYLCYTOSINE , *PEPTIDES , *DIABETES in children , *JUVENILE diseases - Abstract
Animal and human studies suggest that prenatal exposure to stress is associated with adverse health outcomes such as type 2 diabetes. Epigenetic modification, such as DNA methylation, is considered one possible underlying mechanism. The 1998 Quebec ice storm provides a unique opportunity to study an independent prenatal stressor on child outcomes. C-peptide is the best measure of endogenous insulin secretion and is widely used in the clinical management of patients with diabetes. The objectives of this study are to determine 1) the extent to which prenatal exposure to disaster-related stress (maternal objective hardship and maternal cognitive appraisal) influences children’s C-peptide secretion, and 2) whether DNA methylation of diabetes-related genes mediates the effects of prenatal stress on C-peptide secretion. Children’s (n = 30) C-peptide secretion in response to an oral glucose tolerance test were assessed in blood at 13½ years. DNA methylation levels of selected type 1 and 2 diabetes-related genes were chosen based upon the genes associated with prenatal maternal objective hardship and/or cognitive appraisal levels. Bootstrapping analyses were performed to determine the mediation effect of DNA methylation. We found that children whose mothers experienced higher objective hardship exhibited higher C-peptide secretion. Cognitive appraisal was not directly associated with C-peptide secretion. DNA methylation of diabetes-related genes had a positive mediation effect of objective hardship on C-peptide secretion: higher objective hardship predicted higher C-peptide secretion through DNA methylation. Negative mediation effects of cognitive appraisal were observed: negative cognitive appraisal predicted higher C-peptide secretion through DNA methylation. However, only one gene, LTA, remained a significant mediator of cognitive appraisal on C-peptide secretion after the conservative Bonferroni multiple corrections. Our findings suggest that DNA methylation could act as an intervening variable between prenatal stress and metabolic outcomes, highlighting the importance of epigenetic mechanisms in response to environmental factors. [ABSTRACT FROM AUTHOR]
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- 2018
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13. Attenuated expression of MTR in both prenatally androgenized mice and women with the hyperandrogenic phenotype of PCOS.
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Lei, Lei, Ding, Lijun, Su, Jing, Liu, Mengyuan, Shi, Qingqing, Zhou, Jianjun, Sun, Haixiang, and Yan, Guijun
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POLYCYSTIC ovary syndrome , *HYPERANDROGENISM , *DISEASES in women , *ETIOLOGY of diseases , *MICROARRAY technology , *LABORATORY mice - Abstract
Polycystic ovary syndrome (PCOS) is a common endocrine, metabolic and heterogeneous disorder in women of reproductive age, the exact etiology of which remains unknown. To unravel the molecular mechanisms underlying the hyperandrogenic phenotype of PCOS, prenatally androgenized (PNA) mice were used to mimic this phenotype in women with PCOS. Using microarray analysis, 1188 differentially expressed genes, including 671 upregulated and 517 downregulated genes, were identified in ovaries from PNA mice. Five differentially expressed genes (Aldh1a7, Bhmt, Mtr, Nrcam, Ptprg) were validated, and decreased MTR expression was shown in ovaries of PNA mice. In addition, results from qRT-PCR showed decreased MTR expression in granulosa cells (GCs) from women with the hyperandrogenic phenotype of PCOS. Serum levels of S-adenosyl methionine (SAM), the downstream product of MTR, were also decreased in PNA mice and women with the hyperandrogenic phenotype of PCOS. Our study provides evidence that the hyperandrogenic phenotype of PCOS is linked to abnormal folate one-carbon metabolism. [ABSTRACT FROM AUTHOR]
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- 2017
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14. Increased microRNA-93-5p inhibits osteogenic differentiation by targeting bone morphogenetic protein-2.
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Zhang, Ying, Wei, Qiu-Shi, Ding, Wei-Bin, Zhang, Lei-Lei, Wang, Hui-Chao, Zhu, Ying-Jie, He, Wei, Chai, Yu-Na, and Liu, You-Wen
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MICRORNA genetics ,OSTEONECROSIS ,TREATMENT of fractures ,MICRORNA ,ANTISENSE RNA ,THERAPEUTICS - Abstract
Background and purpose: Trauma-induced osteonecrosis of the femoral head (TIONFH) is a major complication of femoral neck fractures. Degeneration and necrosis of subchondral bone can cause collapse, which results in hip joint dysfunction in patients. The destruction of bone metabolism homeostasis is an important factor for osteonecrosis. MicroRNAs (miRNAs) have an important role in regulating osteogenic differentiation, but the mechanisms underlying abnormal bone metabolism of TIONFH are poorly understood. In this study, we screened specific miRNAs in TIONFH by microarray and further explored the mechanism of osteogenic differentiation. Design: Blood samples from patients with TIONFH and patients without necrosis after trauma were compared by microarray, and bone collapse of necrotic bone tissue was evaluated by micro-CT and immunohistochemistry. To confirm the relationship between miRNA and osteogenic differentiation, we conducted cell culture experiments. We found that many miRNAs were significantly different, including miR-93-5p; the increase in this miRNA was verified by Q-PCR. Comparison of the tissue samples showed that miR-93-5p expression increased, and alkaline phosphatase (ALP) and osteopontin (OPN) levels decreased, suggesting miR-93-5p may be involved in osteogenic differentiation. Further bioinformatics analysis indicated that miR-93-5p can target bone morphogenetic protein 2 (BMP-2). A luciferase gene reporter assay was performed to confirm these findings. By simulating and/or inhibiting miR-93-5p expression in human bone marrow mesenchymal stem cells, we confirmed that osteogenic differentiation-related indictors, including BMP-2, Osterix, Runt-related transcription factor, ALP and OPN, were decreased by miR-93-5p. Conclusion: Our study showed that increased miR-93-5p in TIONFH patients inhibited osteogenic differentiation, which may be associated with BMP-2 reduction. Therefore, miR-93-5p may be a potential target for prevention of TIONFH. [ABSTRACT FROM AUTHOR]
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- 2017
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15. Identification of a Novel Gene for Biosynthesis of a Bacteroid-Specific Electron Carrier Menaquinone
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Fuli Xie, Zhi Wang, Hui Xu, Lei Lei, Youguo Li, and Guojun Cheng
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Root nodule ,Sequence analysis ,Ubiquinone ,Applied Microbiology ,Mutant ,Protein domain ,Molecular Sequence Data ,Gene Identification and Analysis ,lcsh:Medicine ,Electrons ,Biology ,Real-Time Polymerase Chain Reaction ,Biochemistry ,Microbiology ,Methylation ,Mass Spectrometry ,Molecular Genetics ,Plant Microbiology ,Species Specificity ,Genetics ,Cloning, Molecular ,lcsh:Science ,Symbiosis ,Gene ,Chromatography, High Pressure Liquid ,Regulation of gene expression ,Multidisciplinary ,lcsh:R ,Microbial Mutation ,Genetic Complementation Test ,Mesorhizobium ,Vitamin K 2 ,Astragalus Plant ,Gene Expression Regulation, Bacterial ,Methyltransferases ,Sequence Analysis, DNA ,biology.organism_classification ,Molecular biology ,Biosynthetic Pathways ,Complementation ,Phenotype ,Genes, Bacterial ,Mutation ,Rhizobium ,lcsh:Q ,Root Nodules, Plant ,Research Article - Abstract
Ubiquinone (UQ) has been considered as an electron mediator in electron transfer that generates ATP in Rhizobium under both free-living and symbiosis conditions. When mutated, the dmtH gene has a symbiotic phenotype of forming ineffective nodules on Astragalus sinicus. The gene was isolated from a Mesorhizobium huakuii 7653R transposon-inserted mutant library. The DNA sequence and conserved protein domain analyses revealed that dmtH encodes demethylmenaquinone (DMK) methyltransferase, which catalyzes the terminal step of menaquinone (MK) biosynthesis. Comparative analysis indicated that dmtH homologs were present in only a few Rhizobia. Real-time quantitative PCR showed dmtH is a bacteroid-specific gene. The highest expression was seen at 25 days after inoculation of strain 7653R. Gene disruption and complementation tests demonstrated that the dmtH gene was essential for bacteroid development and symbiotic nitrogen fixation ability. MK and UQ were extracted from the wild type strain 7653R and mutant strain HK116. MK-7 was accumulated under microaerobic condition and UQ-10 was accumulated under aerobic condition in M. huakuii 7653R. The predicted function of DmtH protein was confirmed by the measurement of methyltransferase activity in vitro. These results revealed that MK-7 was used as an electron carrier instead of UQ in M. huakuii 7653R bacteroids.
- Published
- 2011
16. Role of PCSK5 Expression in Mouse Ovarian Follicle Development: Identification of the Inhibin α- and β-Subunits as Candidate Substrates
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Lei Lei, Sarah E. Kiesewetter, Min Xu, Monica Antenos, Anjali Malipatil, and Teresa K. Woodruff
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Anatomy and Physiology ,lcsh:Medicine ,Gene Expression ,Biochemistry ,Substrate Specificity ,Mice ,0302 clinical medicine ,Ovarian Follicle ,Reproductive Physiology ,Gene expression ,Molecular Cell Biology ,Subtilisins ,lcsh:Science ,Furin ,Cells, Cultured ,Inhibin-beta Subunits ,Regulation of gene expression ,0303 health sciences ,Multidisciplinary ,Gene Expression Regulation, Developmental ,Activins ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Proprotein Convertase 5 ,Female ,Folliculogenesis ,Proprotein Convertases ,hormones, hormone substitutes, and hormone antagonists ,Research Article ,endocrine system ,Cell Physiology ,animal structures ,Biology ,03 medical and health sciences ,Growth Factors ,medicine ,Animals ,Humans ,Inhibins ,RNA, Messenger ,Ovarian follicle ,Secretory pathway ,030304 developmental biology ,Messenger RNA ,lcsh:R ,Reproductive System ,Proteins ,Proprotein convertase ,Molecular biology ,Hormones ,Animals, Newborn ,biology.protein ,lcsh:Q ,Protein Translation - Abstract
Inhibin and activin are essential dimeric glycoproteins belonging to the transforming growth factor-beta (TGFβ) superfamily. Inhibin is a heterodimer of α- and β-subunits, whereas activin is a homodimer of β-subunits. Production of inhibin is regulated during the reproductive cycle and requires the processing of pro-ligands to produce mature hormone. Furin is a subtilisin-like proprotein convertase (proconvertase) that activates precursor proteins by cleavage at basic sites during their transit through the secretory pathway and/or at the cell surface. We hypothesized that furin-like proconvertases are central regulators of inhibin α- and β-subunit processing within the ovary. We analyzed the expression of the proconvertases furin, PCSK5, PCSK6, and PCSK7 in the developing mouse ovary by real-time quantitative RT-PCR. The data showed that proconvertase enzymes are temporally expressed in ovarian cells. With the transition from two-layer secondary to pre-antral follicle, only PCSK5 mRNA was significantly elevated. Activin A selectively enhanced expression of PCSK5 mRNA and decreased expression of furin and PCSK6 in cultured two-layer secondary follicles. Inhibition of proconvertase enzyme activity by dec-RVKR-chloromethylketone (CMK), a highly specific and potent competitive inhibitor of subtilisin-like proconvertases, significantly impeded both inhibin α- and β-subunit maturation in murine granulosa cells. Overexpression of PC5/6 in furin-deficient cells led to increased inhibin α- and β(B)-subunit maturation. Our data support the role of proconvertase PCSK5 in the processing of ovarian inhibin subunits during folliculogenesis and suggest that this enzyme may be an important regulator of inhibin and activin bioavailability.
- Published
- 2011
17. Circulating Betatrophin Levels and Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis.
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Kong, Fei-Juan, Ma, Lei-Lei, Li, Ge, Chen, Yi-Xin, and Zhou, Jia-Qiang
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GESTATIONAL diabetes , *BLOOD testing , *THIRD trimester of pregnancy , *BODY mass index , *GLUCOSE tolerance tests - Abstract
Objective: The association between circulating betatrophin levels and gestational diabetes mellitus (GDM) is controversial. The aim of our study was to systematically review available literature linking betatrophin to GDM for a comprehensive understanding of the relationship between circulating betatrophin levels and GDM in human. Methods: PubMed, The Cochrane Library, Medline and CNKI were searched for studies published up to August 2016. Manual searches of references of the relevant original studies were conducted. Pooled estimates were measured using the fixed or random effect model. Overall effect was reported in a standard mean difference (SMD). All data were analyzed with Review Manager 5.3 and Stata 12.0. Results: Of 25 references reviewed, 8 studies met our inclusion criteria and contributed to meta-analysis. All the studies were used to evaluate the relationship between betatrophin levels in blood and GDM. Betatrophin levels were significantly elevated in women with GDM compared with those without GDM (SMD = 1.05; 95% CI: 0.41–1.68, P = 0.001). This evidence was more consistent among women with betatrophin blood draw during the third trimester (SMD = 1.3, 95% CI: 1–1.61, P < 0.001) and for women BMI ≥ 28 kg/m2 (SMD = 1.53, 95% CI: 1.30–1.75, P < 0.001). Conclusions: The evidences from this meta-analysis indicated that the levels of circulating betatrophin were significantly elevated among women with GDM compared with women with normal glucose tolerance, especially with BMI ≥ 28 kg/m2 and in the third trimester. [ABSTRACT FROM AUTHOR]
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- 2017
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18. A Segmentation Method for Lung Parenchyma Image Sequences Based on Superpixels and a Self-Generating Neural Forest.
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Liao, Xiaolei, Zhao, Juanjuan, Jiao, Cheng, Lei, Lei, Qiang, Yan, and Cui, Qiang
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PULMONARY nodules ,LUNG disease diagnosis ,IMAGE segmentation ,COMPUTED tomography ,PIXELS ,CLUSTER analysis (Statistics) - Abstract
Background: Lung parenchyma segmentation is often performed as an important pre-processing step in the computer-aided diagnosis of lung nodules based on CT image sequences. However, existing lung parenchyma image segmentation methods cannot fully segment all lung parenchyma images and have a slow processing speed, particularly for images in the top and bottom of the lung and the images that contain lung nodules. Method: Our proposed method first uses the position of the lung parenchyma image features to obtain lung parenchyma ROI image sequences. A gradient and sequential linear iterative clustering algorithm (GSLIC) for sequence image segmentation is then proposed to segment the ROI image sequences and obtain superpixel samples. The SGNF, which is optimized by a genetic algorithm (GA), is then utilized for superpixel clustering. Finally, the grey and geometric features of the superpixel samples are used to identify and segment all of the lung parenchyma image sequences. Results: Our proposed method achieves higher segmentation precision and greater accuracy in less time. It has an average processing time of 42.21 seconds for each dataset and an average volume pixel overlap ratio of 92.22 ± 4.02% for four types of lung parenchyma image sequences. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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19. Clinicopathological Characteristics of Mucinous Breast Cancer: A Retrospective Analysis of a 10-Year Study.
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Lei, Lei, Yu, Xingfei, Chen, Bo, Chen, Zhanhong, and Wang, Xiaojia
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BREAST cancer prognosis , *BREAST cancer diagnosis , *ESTROGEN receptors , *GENE expression , *LOGISTIC regression analysis , *PROGESTERONE receptors - Abstract
Background: Mucinous breast carcinoma (MC) is a special type of breast cancer that presents with a large amount of extracellular mucin. MC comprises approximately 4% of all invasive breast cancers. This type of tumor has a better prognosis and higher incidence in peri- and post-menopausal patients. Pathologically, there are two main subtypes of MC: pure and mixed. In this study, we describe 10 years of experience with MC at the Zhejiang Cancer Hospital in China, specifically, clinical data, histological findings and immunohistochemical features. Methods: We identified MC patients who were diagnosed as operable and completed clinical treatment from January 2001 to January 2011. The clinicopathological data included the age at diagnosis, tumor size, TNM stage, presence and number of lymph node (LN) metastases, estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2) status and p53 expression. If the tumor was defined as mixed mucinous carcinoma (MMC), IHC was performed on a non-mucinous part, such as invasive ductal and lobular cancer. We evaluated the clinical characteristics of all MC patients using chi-square, one-way ANOVA and LSD tests. We also studied the correlations between all of the clinical parameters and LN metastasis in a binary logistic regression analysis. We used ten consecutive years of data that were collected at Zhejiang Cancer Hospital. Results: We identified 48 cases of pure mucinous carcinoma (PMC) and 77 cases of MMC. The 48 PMC cases consisted of 38 PMC-A and 10 PMC-B subtypes. The MMCs were divided into two groups, those with partial mixed mucinous breast carcinoma (pMMC, 58 cases) and those with main mixed mucinous breast carcinoma (mMMC, 19 cases). pMMC was defined by tumors with less than 50% mucinous components, while mMMC was defined by tumors where the mucinous component accounted for 50% to 90% of the tumor. No significant differences in the clinicopathological characteristics were noted between the patients with PMC-A and those with PMC-B. The tumor size was larger in the mMMC than PMC cases (44.84 mm vs. 30.06 mm, p = 0.021). The number of positive LN metastases was greater in pMMC than PMC patients (p = 0.024). The clinical stages were significantly different among the three groups, with the pMMC group having more stage III-IV patients than the other two groups (p = 0.005). The incidence of LN metastasis was also higher in the pMMC cases (pMMC vs. mMMC and PMC, 50% vs. 31.58% and 18.75%, p = 0.003). The PMC patients had much lower p53 expression than the other two groups (PMC vs. pMMC and mMMC, 27.08% vs. 55.17% and 57.89%, p = 0.007). The tumor size (>30mm), p53 expression and less proportion of the mucinous component are associated with risk of LN metastasis. Conclusion: Based on the results of this study, we conclude that the tumor size, status of LN metastasis, clinical stage, and p53 mutation rate may differ between MMC and PMC patients. The tumor size (>30mm), p53 mutation and less proportion of the mucinous component should be considered risk factors of LN metastasis in MC patients. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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20. Remodeling of Mitochondrial Flashes in Muscular Development and Dystrophy in Zebrafish.
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Zhang, Meiling, Sun, Tao, Jian, Chongshu, Lei, Lei, Han, Peidong, Lv, Quanlong, Yang, Ran, Zhou, Xiaohai, Xu, Jiejia, Hu, Yingchun, Men, Yongfan, Huang, Yanyi, Zhang, Chuanmao, Zhu, Xiaojun, Wang, Xianhua, Cheng, Heping, and Xiong, Jing-Wei
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MUSCULAR dystrophy ,ZEBRA danio ,SKELETAL muscle ,MORPHOGENESIS ,MITOCHONDRIAL enzymes ,NAD(P)H dehydrogenases ,PATHOLOGICAL physiology - Abstract
Mitochondrial flash (mitoflash) is a highly-conserved, universal, and physiological mitochondrial activity in isolated mitochondria, intact cells, and live organisms. Here we investigated developmental and disease-related remodeling of mitoflash activity in zebrafish skeletal muscles. In transgenic zebrafish expressing the mitoflash reporter cpYFP, in vivo imaging revealed that mitoflash frequency and unitary properties underwent multiphasic and muscle type-specific changes, accompanying mitochondrial morphogenesis from 2 to 14 dpf. In particular, short (S)-type mitoflashes predominated in early muscle formation, then S-, transitory (T)- and regular (R)-type mitoflashes coexisted during muscle maturation, followed by a switch to R-type mitoflashes in mature skeletal muscles. In early development of muscular dystrophy, we found accelerated S- to R-type mitoflash transition and reduced mitochondrial NAD(P)H amidst a remarkable cell-to-cell heterogeneity. This study not only unravels a profound functional and morphological remodeling of mitochondria in developing and diseased skeletal muscles, but also underscores mitoflashes as a useful reporter of mitochondrial function in milieu of live animals under physiological and pathophysiological conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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21. Differential Gene Expression Profile in the Rat Caudal Vestibular Nucleus is Associated with Individual Differences in Motion Sickness Susceptibility.
- Author
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Wang, Jun-Qin, Qi, Rui-Rui, Zhou, Wei, Tang, Yi-Fan, Pan, Lei-Lei, and Cai, Yi-Ling
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GENE expression ,LABORATORY rats ,VESTIBULAR apparatus ,INDIVIDUAL differences ,MOTION sickness ,DISEASE susceptibility - Abstract
Objective: To identify differentially expressed genes associated with motion sickness (MS) susceptibility in the rat caudal vestibular nucleus. Methods: We identified MS susceptible (MSS) and insusceptible (inMSS) rats by quantifying rotation-induced MS symptoms: defecation and spontaneous locomotion activity. Microarray analysis was used to screen differentially expressed genes in the caudal vestibular nucleus (CVN) after rotation. Plasma stress hormones were identified by radioimmunoassay. Candidate genes were selected by bioinformatics analysis and the microarray results were verified by real-time quantitative-PCR (RT-qPCR) methods. By using Elvax implantation, receptor antagonists or recombinant adenovirus targeting the candidate genes were applied to the CVN to evaluate their contribution to MS susceptibility variability. Validity of gene expression manipulation was verified by RT-qPCR and western blot analysis. Results: A total of 304 transcripts were differentially expressed in the MSS group compared with the inMSS group. RT-qPCR analysis verified the expression pattern of candidate genes, including nicotinic cholinergic receptor (nAchR) α3 subunit, 5-hydroxytryptamine receptor 4 (5-HT
4 R), tachykinin neurokinin-1 (NK1 R), γ-aminobutyric acid A receptor (GABAA R) α6 subunit, olfactory receptor 81 (Olr81) and homology 2 domain-containing transforming protein 1 (Shc1). In MSS animals, the nAchR antagonist mecamylamine significantly alleviated rotation-induced MS symptoms and the plasma β-endorphin response. The NK1 R antagonist CP99994 and Olr81 knock-down were effective for the defecation response, while the 5-HT4 R antagonist RS39604 and Shc1 over-expression showed no therapeutic effect. In inMSS animals, rotation-induced changes in spontaneous locomotion activity and the plasma β-endorphin level occurred in the presence of the GABAA R antagonist gabazine. Conclusion: Our findings suggested that the variability of the CVN gene expression profile after motion stimulation might be a putative molecular basis for individual differences in MS susceptibility and provide information for the development of new therapeutic strategies for MSS individuals. [ABSTRACT FROM AUTHOR]- Published
- 2015
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22. DNA Methylation Signatures Triggered by Prenatal Maternal Stress Exposure to a Natural Disaster: Project Ice Storm.
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Cao-Lei, Lei, Massart, Renaud, Suderman, Matthew J., Machnes, Ziv, Elgbeili, Guillaume, Laplante, David P., Szyf, Moshe, and King, Suzanne
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DNA methylation , *NATURAL disasters , *T cells , *EPIGENETICS , *PREGNANCY , *PSYCHOLOGICAL stress , *MEDICAL care - Abstract
Background: Prenatal maternal stress (PNMS) predicts a wide variety of behavioral and physical outcomes in the offspring. Although epigenetic processes may be responsible for PNMS effects, human research is hampered by the lack of experimental methods that parallel controlled animal studies. Disasters, however, provide natural experiments that can provide models of prenatal stress. Methods: Five months after the 1998 Quebec ice storm we recruited women who had been pregnant during the disaster and assessed their degrees of objective hardship and subjective distress. Thirteen years later, we investigated DNA methylation profiling in T cells obtained from 36 of the children, and compared selected results with those from saliva samples obtained from the same children at age 8. Results: Prenatal maternal objective hardship was correlated with DNA methylation levels in 1675 CGs affiliated with 957 genes predominantly related to immune function; maternal subjective distress was uncorrelated. DNA methylation changes in SCG5 and LTA, both highly correlated with maternal objective stress, were comparable in T cells, peripheral blood mononuclear cells (PBMCs) and saliva cells. Conclusions: These data provide first evidence in humans supporting the conclusion that PNMS results in a lasting, broad, and functionally organized DNA methylation signature in several tissues in offspring. By using a natural disaster model, we can infer that the epigenetic effects found in Project Ice Storm are due to objective levels of hardship experienced by the pregnant woman rather than to her level of sustained distress. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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23. Selection and Expression Profiles of Reference Genes in Mouse Preimplantation Embryos of Different Ploidies at Various Developmental Stages.
- Author
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Gu, Yanli, Shen, Xinghui, Zhou, Dongjie, Wang, Zhendong, Zhang, Na, Shan, Zhiyan, Jin, Lianhong, and Lei, Lei
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GENE expression ,REVERSE transcriptase polymerase chain reaction ,PREIMPLANTATION genetic diagnosis ,DEVELOPMENTAL biology ,EMBRYOS ,LABORATORY mice - Abstract
Real-time reverse transcription quantitative polymerase chain reaction (qPCR) has become the most frequently used system for studies of gene expression. Manystudies have provided reliable evidence that the transcription levels of reference genes are not constant at different developmental stages and in different experimental conditions. However, suitable reference genes which are stably expressed in polyploid preimplantation embryos of different developmental stages have not yet been identified. Therefore, it is critical to verify candidate reference genes to analyze gene expression accurately in both diploid and polyploid embryos. We examined the expression levels of 12 candidate reference genes in preimplantation embryos of four different ploidies at six developmental stages. Stability analysis of the reference genes was performed by four independent software programs, and the stability of three genes was evaluated by comparison with the Oct4 expression level during preimplantation development in diploid embryos. The expression levels of most genes in the polyploid embryos were higher than that in the diploid embryos, but the increasing degree were disproportionate with the ploidies. There were no significant difference in reference gene expressions among embryos of different ploidies when they reached the morula stage, and the expression level remained flat until the blastocyst stage. Ubc, Ppia, and Pgk1 were the three most stable reference genes in diploid and polyploid embryos. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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24. Acetobixan, an Inhibitor of Cellulose Synthesis Identified by Microbial Bioprospecting.
- Author
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Xia, Ye, Lei, Lei, Brabham, Chad, Stork, Jozsef, Strickland, James, Ladak, Adam, Gu, Ying, Wallace, Ian, and DeBolt, Seth
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CELLULOSE synthase , *ARABIDOPSIS , *BIOPROSPECTING , *MICROBIAL enzymes , *CELL membranes , *BIOTECHNOLOGY - Abstract
In plants, cellulose biosynthesis is an essential process for anisotropic growth and therefore is an ideal target for inhibition. Based on the documented utility of small-molecule inhibitors to dissect complex cellular processes we identified a cellulose biosynthesis inhibitor (CBI), named acetobixan, by bio-prospecting among compounds secreted by endophytic microorganisms. Acetobixan was identified using a drug-gene interaction screen to sift through hundreds of endophytic microbial secretions for one that caused synergistic reduction in root expansion of the leaky AtcesA6prc1-1 mutant. We then mined this microbial secretion for compounds that were differentially abundant compared with Bacilli that failed to mimic CBI action to isolate a lead pharmacophore. Analogs of this lead compound were screened for CBI activity, and the most potent analog was named acetobixan. In living Arabidopsis cells visualized by confocal microscopy, acetobixan treatment caused CESA particles localized at the plasma membrane (PM) to rapidly re-localize to cytoplasmic vesicles. Acetobixan inhibited 14C-Glc uptake into crystalline cellulose. Moreover, cortical microtubule dynamics were not disrupted by acetobixan, suggesting specific activity towards cellulose synthesis. Previous CBI resistant mutants such as ixr1-2, ixr2-1 or aegeus were not cross resistant to acetobixan indicating that acetobixan targets a different aspect of cellulose biosynthesis. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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25. Effects of Huanglian-Jie-Du-Tang and Its Modified Formula on the Modulation of Amyloid-β Precursor Protein Processing in Alzheimer's Disease Models.
- Author
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Durairajan, Siva Sundara Kumar, Huang, Ying-Yu, Yuen, Pui-Yee, Chen, Lei-Lei, Kwok, Ka-Yan, Liu, Liang-Feng, Song, Ju-Xian, Han, Quan-Bin, Xue, Lei, K. Chung, Sookja, Huang, Jian-Dong, Baum, Larry, Senapati, Sanjib, and Li, Min
- Subjects
AMYLOID ,PROTEIN precursors ,ALZHEIMER'S disease diagnosis ,HERBAL medicine ,CEREBRAL ischemia ,MENTAL health - Abstract
Huanglian-Jie-Du-Tang (HLJDT) is a famous traditional Chinese herbal formula that has been widely used clinically to treat cerebral ischemia. Recently, we found that berberine, a major alkaloid compound in HLJDT, reduced amyloid-β (Aβ) accumulation in an Alzheimer’s disease (AD) mouse model. In this study, we compared the effects of HLJDT, four single component herbs of HLJDT (Rhizoma coptidis (RC), Radix scutellariae (RS), Cortex phellodendri (CP) and Fructus gardenia (FG)) and the modified formula of HLJDT (HLJDT-M, which is free of RS) on the regulatory processing of amyloid-β precursor protein (APP) in an in vitro model of AD. Here we show that treatment with HLJDT-M and its components RC, CP, and the main compound berberine on N2a mouse neuroblastoma cells stably expressing human APP with the Swedish mutation (N2a-SwedAPP) significantly decreased the levels of full-length APP, phosphorylated APP at threonine 668, C-terminal fragments of APP, soluble APP (sAPP)-α and sAPPβ-Swedish and reduced the generation of Aβ peptide in the cell lysates of N2a-SwedAPP. HLJDT-M showed more significant APP- and Aβ- reducing effects than berberine, RC or CP treatment alone. In contrast, HLJDT, its component RS and the main active compound of RS, baicalein, strongly increased the levels of all the metabolic products of APP in the cell lysates. The extract from FG, however, did not influence APP modulation. Interestingly, regular treatment of TgCRND8 APP transgenic mice with baicalein exacerbated the amyloid plaque burden, APP metabolism and Aβ production. Taken together, these data provide convincing evidence that HLJDT and baicalein treatment can increase the amyloidogenic metabolism of APP which is at least partly responsible for the baicalein-mediated Aβ plaque increase in the brains of TgCRND8 mice. On the other hand, HLJDT-M significantly decreased all the APP metabolic products including Aβ. Further study of HLJDT-M for therapeutic use in treating AD is warranted. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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26. TaMFT-A1 Is Associated with Seed Germination Sensitive to Temperature in Winter Wheat.
- Author
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Lei, Lei, Zhu, Xinkai, Wang, Shuwen, Zhu, Meirong, Carver, Brett F., and Yan, Liuling
- Subjects
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SEED viability , *GERMINATION , *WINTER wheat , *SEEDLINGS , *PLANT development , *PLANT biomass , *EFFECT of temperature on plants - Abstract
The ability of seed to germinate under favorable environmental conditions is critical for seedling emergence, plant establishment, subsequent development and growth of adult plants, and it is controlled by internal genetic factors and external environmental factors. Winter wheat in the southern Great Plains is often planted six weeks before the optimal planting date to produce more biomass for cattle grazing during the winter season. A high seed germination rate in this higher soil temperature environment is required for this specific management system. In this study, a major QTL for temperature-sensitive germination was mapped on the short arm of chromosome 3A (QTsg.osu-3A) in a RIL population generated from two winter wheat cultivars. Furthermore, TaMFT-A1, previously reported to regulate seed dormancy and pre-harvest sprouting in spring wheat cultivars, was mapped tightly associated with the peak of QTsg.osu-3A. However, allelic variation in TaMFT-A1 between the two winter wheat cultivars differed from that was observed in spring wheat cultivars. There were 87 SNPs (single nucleotide polymorphisms) and 12 indels (insertions/deletions) in TaMFT-A1 between the Jagger allele for high germination and the 2174 allele for low germination in the after-ripened seeds, in comparison with 2 SNPs between the two alleles for differential pre-harvest sprouting in spring wheat cultivars. The Jagger TaMFT-A1 allele is a novel haplotype and appears extensively in winter wheat cultivars. TaMFT-A1 transcript levels were up-regulated by high temperature but down-regulated by low temperature or seed storage time. These findings suggest that TaMFT-A1 may invoke different mechanisms for controlling seed dormancy/germination among winter wheat cultivars. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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27. Identification of a Novel Nuclear Localization Signal Sequence in Chlamydia trachomatis-Secreted Hypothetical Protein CT311
- Author
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Lei, Lei, Dong, Xiaohua, Li, Zhongyu, and Zhong, Guangming
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CELLULAR signal transduction , *AMINO acid sequence , *CHLAMYDIA trachomatis , *CELL nuclei , *GENE expression , *TARGETING (Nuclear strategy) , *MAMMALIAN cell cycle - Abstract
We previously reported that Chlamydia trachomatis hypothetical protein CT311 was secreted out of chlamydial inclusion and into host cell cytosol. We now found that CT311 further entered host cell nucleus at the late stage of infection and continued to accumulate in the nucleus of C. trachomatis-infected cells. When CT311 was expressed via a transgene in mammalian cells, CT311 protein was exclusively detected in the nucleus, suggesting that CT311 by itself is sufficient for nuclear targeting. However, preexisting nuclear CT311 did not affect subsequent chlamydial infection. Using deletion constructs, we mapped a nuclear localization signal sequence of CT311 to residues 21 to 63 (21AVEGKPLSRAAQLRERRKDLHVSGKPSPRYALKKRALEAKKNK63). This sequence was sufficient for targeting a heterologous protein into mammalian cell nucleus and it contains two independent clusters of basic residues (34RERRK38 and 53KKRALEAKKNK63 respectively). Deletion or alanine substitution of the basic residues in either cluster led to loss of nuclear targeting activity, suggesting that both clusters are critical for the nuclear targeting function. These observations have demonstrated that the hypothetical protein CT311 possesses a novel nuclear localization signal sequence with dual modules of basic residues for targeting host cell nucleus during Chlamydia trachomatis infection. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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28. Rottlerin-Mediated Inhibition of Chlamydia trachomatis Growth and Uptake of Sphingolipids Is Independent of p38-Regulated/Activated Protein Kinase (PRAK).
- Author
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Lei Lei, Zhongyu Li, Guangming Zhong, and Ojcius, David M.
- Subjects
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MOLECULES , *CHLAMYDIA trachomatis , *SPHINGOLIPIDS , *LIPIDS , *PROTEIN kinases , *GOLGI apparatus - Abstract
We previously found that rottlerin, a plant-derived small molecule compound, profoundly inhibited Chlamydia trachomatis growth and blocked sphingolipid trafficking from host cell Golgi into chlamydial inclusions. Since the p38-regulated/activated protein kinase (PRAK) is a known target of rottlerin and is activated in Chlamydia trachomatis-infected cells, we investigated the potential role of this kinase in rottlerin-mediated anti-chlamydial activity. However, we found that a PRAK-specific inhibitor failed to inhibit chlamydial growth, suggesting that the kinase activity of PRAK may not be required for chlamydial intracellular replication. This conclusion was supported by the observation that chlamydial organisms replicated equally well in mouse embryonic fibroblast cells with or without PRAK. Moreover, neither the PRAK inhibitor nor PRAK deficiency altered host sphingolipid trafficking into chlamydial inclusions. Finally, rottlerin maintained its anti-chlamydial activity in PRAK-deficient cells. Together, these observations have demonstrated that PRAK is not required for either the rottlerin-mediated anti-chlamydial activity or rottlerin inhibition of sphingolipid trafficking, suggesting that rottlerin may achieve its inhibitory role by targeting other host factors. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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29. RBMS3at 3p24 Inhibits Nasopharyngeal Carcinoma Development via Inhibiting Cell Proliferation, Angiogenesis, and Inducing Apoptosis.
- Author
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Chen, Juan, Dora Lai-Wan Kwong, Cai-Lei Zhu, Lei-Lei Chen, Sui-Sui Dong, Li-Yi Zhang, Jun Tian, Chu-Bo Qi, Ting-Ting Cao, Go Wong, Alissa Michelle, Kar-Lok Kong, Yan Li, Ming Liu, Li Fu, and Xin-Yuan Guan
- Subjects
NASOPHARYNX cancer ,ANTINEOPLASTIC agents ,METASTASIS ,NEOVASCULARIZATION inhibitors ,APOPTOSIS ,TUMOR suppressor genes - Abstract
Deletion of the short arm of chromosome 3 is one of the most frequent genetic alterations in many solid tumors including nasopharyngeal carcinoma (NPC), suggesting the existence of one or more tumor suppressor genes (TSGs) within the frequently deleted region. A putative TSG RBMS3 (RNA binding motif, single stranded interacting protein 3), located at 3p24- p23, has been identified in our previous study. Here, we reported that downregulation of RBMS3 was detected in 3/3 NPC cell lines and 13/15 (86.7%) primary NPC tissues. Functional studies using both overexpression and suppression systems demonstrated that RBMS3 has a strong tumor suppressive role in NPC. The tumor suppressive mechanism of RBMS3 was associated with its role in cell cycle arrest at the G1/S checkpoint by upregulating p53 and p21, downregulating cyclin E and CDK2, and the subsequent inhibition of Rb-ser780. Further analysis demonstrated that RBMS3 had a pro-apoptotic role in a mitochondrial-dependent manner via activation of caspase-9 and PARP. Finally, RBMS3 inhibited microvessel formation, which may be mediated by down-regulation of MMP2 and β-catenin and inactivation of its downstream targets, including cyclin-D1, c-Myc, MMP7, and MMP9. Taken together, our findings define a function for RBMS3 as an important tumor suppressor gene in NPC. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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30. Role of PCSK5 Expression in Mouse Ovarian Follicle Development: Identification of the Inhibin a- and b-Subunits as Candidate Substrates.
- Author
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Antenos, Monica, Lei Lei, Min Xu, Malipatil, Anjali, Kiesewetter, Sarah, and Woodruff, Teresa K.
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- *
OVARIES , *SEX hormones , *GLYCOPROTEINS , *INHIBIN , *ACTIVIN , *GROWTH factors , *PROTEIN precursors , *ENZYMES - Abstract
Inhibin and activin are essential dimeric glycoproteins belonging to the transforming growth factor-beta (TGFb) superfamily. Inhibin is a heterodimer of a- and b-subunits, whereas activin is a homodimer of b-subunits. Production of inhibin is regulated during the reproductive cycle and requires the processing of pro-ligands to produce mature hormone. Furin is a subtilisin-like proprotein convertase (proconvertase) that activates precursor proteins by cleavage at basic sites during their transit through the secretory pathway and/or at the cell surface. We hypothesized that furin-like proconvertases are central regulators of inhibin a- and b-subunit processing within the ovary. We analyzed the expression of the proconvertases furin, PCSK5, PCSK6, and PCSK7 in the developing mouse ovary by real-time quantitative RT-PCR. The data showed that proconvertase enzymes are temporally expressed in ovarian cells. With the transition from two-layer secondary to pre-antral follicle, only PCSK5 mRNA was significantly elevated. Activin A selectively enhanced expression of PCSK5 mRNA and decreased expression of furin and PCSK6 in cultured two-layer secondary follicles. Inhibition of proconvertase enzyme activity by dec-RVKR-chloromethylketone (CMK), a highly specific and potent competitive inhibitor of subtilisin-like proconvertases, significantly impeded both inhibin α- and β-subunit maturation in murine granulosa cells. Overexpression of PC5/6 in furin-deficient cells led to increased inhibin α- and βB-subunit maturation. Our data support the role of proconvertase PCSK5 in the processing of ovarian inhibin subunits during folliculogenesis and suggest that this enzyme may be an important regulator of inhibin and activin bioavailability. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
31. Characterization of the Specific CD4+ T Cell Response against the F Protein during Chronic Hepatitis C Virus Infection.
- Author
-
De-Yong Gao, Gen-Di Jin, Bi-Lian Yao, Dong-Hua Zhang, Lei-Lei Gu, Zhi-Meng Lu, Qiming Gong, Yu-Chun Lone, Qiang Deng, and Xin-Xin Zhang
- Subjects
HEPATITIS C virus ,IMMUNOGLOBULINS ,INTERFERONS ,T cells ,LIVER diseases ,BLOOD vessels ,FERTILIZATION in vitro ,EPITOPES ,TRANSGENIC animals - Abstract
Background: The hepatitis C virus (HCV) Alternate Reading Frame Protein (ARFP or F protein) presents a double-frame shift product of the HCV core gene. We and others have previously reported that the specific antibodies against the F protein could be raised in the sera of HCV chronically infected patients. However, the specific CD4
+ T cell responses against the F protein during HCV infection and the pathological implications remained unclear. In the current study, we screened the MHC class II-presenting epitopes of the F protein through HLA-transgenic mouse models and eventually validated the specific CD4+ T cell responses in HCV chronically infected patients. Methodology: DNA vaccination in HLA-DR1 and-DP4 transgenic mouse models, proliferation assay to test the F protein specific T cell response, genotyping of Chronic HCV patients and testing the F-peptide stimulated T cell response in the peripheral blood mononuclear cell (PBMC) by in vitro expansion and interferon (IFN)- γ intracellular staining. Principal Findings: At least three peptides within HCV F protein were identified as HLA-DR or HLA-DP4 presenting epitopes by the proliferation assays in mouse models. Further study with human PBMCs evidenced the specific CD4+ T cell responses against HCV F protein as well in patients chronically infected with HCV. Conclusion: The current study provided the evidence for the first time that HCV F protein could elicit specific CD4+ T cell response, which may provide an insight into the immunopathogenesis during HCV chronic infection. [ABSTRACT FROM AUTHOR]- Published
- 2010
- Full Text
- View/download PDF
32. The Environment, Not Space, Dominantly Structures the Landscape Patterns of the Richness and Composition of the Tropical Understory Vegetation.
- Author
-
Hu, Yue-Hua, Sheng, Da-Yong, Xiang, Yang-Zhou, Yang, Zeng-Jiang, Xu, Da-Ping, Zhang, Ning-Nan, and Shi, Lei-Lei
- Subjects
UNDERSTORY plants ,PLANT diversity ,TROPICAL plants ,BIODIVERSITY ,ECOLOGICAL niche ,PLANTATIONS ,SPATIAL variation - Abstract
The mechanisms driving the spatial patterns of species richness and composition are essential to the understanding of biodiversity. Numerous studies separately identify the contributions of the environment (niche process) and space (neutral process) to the species richness or composition at different scales, but few studies have investigated the contributions of both types of processes in the two types of data at the landscape scale. In this study, we partitioned the spatial variations in all, exotic and native understory plant species richness and composition constrained by environmental variables and space in 134 plots that were spread across 10 counties in Hainan Island in southern China. The 134 plots included 70 rubber (Hevea brasiliensis) plantation plots, 50 eucalyptus (Eucalyptus urophylla) plantation plots, and 14 secondary forest plots. RDA based variation partitioning was run to assess the contribution of environment and space to species richness and composition. The results showed that the environmental variables alone explained a large proportion of the variations in both the species richness and composition of all, native, and exotic species. The RDA results indicated that overstory composition (forest type here) plays a leading role in determining species richness and composition patterns. The alpha and beta diversities of the secondary forest plots were markedly higher than that of the two plantations. In conclusion, niche differentiation processes are the principal mechanisms that shape the alpha and beta diversities of understory plant species in Hainan Island. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
33. Hypercholesterolemic Myocardium Is Vulnerable to Ischemia-Reperfusion Injury and Refractory to Sevoflurane-Induced Protection.
- Author
-
Xu, Yong, Ma, Lei-Lei, Zhou, Chen, Zhang, Fei-Jiang, Kong, Fei-Juan, Wang, Wen-Na, Qian, Ling-Bo, Wang, Can-Can, Liu, Xian-Bao, Yan, Min, and Wang, Jian-An
- Subjects
- *
HYPERCHOLESTEREMIA , *CORONARY disease , *REPERFUSION injury , *SEVOFLURANE , *ANESTHETICS , *LABORATORY rats , *LEFT heart ventricle , *THERAPEUTICS - Abstract
Recent studies have demonstrated that volatile anesthetic postconditioning confers myocardial protection against ischemia-reperfusion (IR) injury through activation of the reperfusion injury salvage kinase (RISK) pathway. As RISK has been shown to be impaired in hypercholesterolemia. Therefore, we investigate whether anesthetic-induced cardiac protection was maintained in hypercholesterolemic rats. In the present study, normocholesteolemic or hypercholesterolemic rat hearts were subjected to 30 min of ischemia and 2 h of reperfusion. Animals received 2.4% sevoflurane for 5 min or 3 cycles of 10-s ischemia/10-s reperfusion. The hemodynamic parameters, including left ventricular developed pressure, left ventricular end-diastolic pressure and heart rate, were continuously monitored. The infarct size, apoptosis, p-Akt, p-ERK1/2, p-GSK3β were determined. We found that both sevoflurane and ischemic postconditioning significantly improved heart pump function, reduced infarct size and increased the phosphorylation of Akt, ERK1/2 and their downstream target of GSK3β in the healthy rats. In the hypercholesterolemic rats, neither sevoflurane nor ischemic postconditioning improved left ventricular hemodynamics, reduced infarct size and increased the phosphorylated Akt, ERK1/2 and GSK3β. In contrast, GSK inhibitor SB216763 conferred cardioprotection against IR injury in healthy and hypercholesterolemic hearts. In conclusions, hyperchoesterolemia abrogated sevoflurane-induced cardioprotection against IR injury by alteration of upstream signaling of GSK3β and acute GSK inhibition may provide a novel therapeutic strategy to protect hypercholesterolemic hearts against IR injury. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
34. Oviduct Infection and Hydrosalpinx in DBA1/j Mice Is Induced by Intracervical but Not Intravaginal Inoculation with Chlamydia muridarum.
- Author
-
Tang, Lingli, Zhang, Hongbo, Lei, Lei, Gong, Siqi, Zhou, Zhiguang, Baseman, Joel, and Zhong, Guangming
- Subjects
OVIDUCT diseases ,CHLAMYDIA trachomatis ,VAGINAL diseases ,VIRAL replication ,LABORATORY mice ,EPITHELIAL cells ,PREVENTION - Abstract
Intravaginal infection with C. muridarum in mice often results in hydrosalpinx similar to that found in women urogenitally infected with C. trachomatis, making the C. muridarum lower genital tract infection murine model suitable for studying C. trachomatis pathogenesis. To our surprise, DBA1/j mice were highly resistant to hydrosalpinx following an intravaginal infection with C. muridarum although these mice were as susceptible to lower genital tract infection as other mouse strains. A significantly lower level of C. muridarum organisms was recovered from the oviduct of DBA1/j mice, correlating the resistance to hydrosalpinx with reduced ascension of C. muridarum to the oviduct. The DBA1/j resistance to hydrosalpinx was effectively overcome by intracervical inoculation with C. muridarum. The intracervically inoculated DBA1/j mice developed severe hydrosalpinx with the highest levels of live C. muridarum organisms recovered from uterine tissue on day 3 and oviduct tissue on day 7 post inoculation while in intravaginally inoculated DBA1/j mice, the peak of live organism recovery from uterine tissue was delayed to day 7 with no rise in the amount of live organisms recovered from the oviduct. These observations have not only validated the correlation between hydrosalpinx and live organism invasion in the oviduct but also demonstrated that the intracervical inoculation, by promoting rapid chlamydial replication in the uterine epithelial cells and ascension to the oviduct of DBA1/j mice, may be used for further understanding chlamydial pathogenic mechanisms. The above findings also suggest that strategies aimed at reducing tubal infection may be most effective in blocking tubal pathology. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
35. Chlamydia trachomatis GlgA Is Secreted into Host Cell Cytoplasm.
- Author
-
Lu, Chunxue, Lei, Lei, Peng, Bo, Tang, Lingli, Ding, Honglei, Gong, Siqi, Li, Zhongyu, Wu, Yimou, and Zhong, Guangming
- Subjects
- *
CHLAMYDIA trachomatis , *SECRETION , *CYTOPLASM , *GLYCOGEN synthases , *CHLAMYDIA infection diagnosis , *CYTOSOL , *CHIMERIC proteins - Abstract
Glycogen has been localized both inside and outside Chlamydia trachomatis organisms. We now report that C. trachomatis glycogen synthase (GlgA) was detected in both chlamydial organism-associated and -free forms. The organism-free GlgA molecules were localized both in the lumen of chlamydial inclusions and in the cytosol of host cells. The cytosolic GlgA displayed a distribution pattern similar to that of a known C. trachomatis-secreted protease, CPAF. The detection of GlgA was specific since the anti-GlgA antibody labeling was only removed by preabsorption with GlgA but not CPAF fusion proteins. GlgA was detectable at 12h and its localization into host cell cytosol only became apparent at 24h after infection. The cytosolic localization of GlgA was conserved among all C. trachomatis serovars. However, the significance of the GlgA secretion into host cell cytoplasm remains unclear since, while expression of chlamydial GlgA in HeLa cells increased glycogen stores, it did not affect a subsequent infection with C. trachomatis. Similar to several other C. trachomatis-secreted proteins, GlgA is immunogenic in women urogenitally infected with C. trachomatis, suggesting that GlgA is expressed and may be secreted into host cell cytosol during C. trachomatis infection in humans. These findings have provided important information for further understanding C. trachomatis pathogenic mechanisms. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
36. Oviduct Infection and Hydrosalpinx in DBA1/j Mice Is Induced by Intracervical but Not Intravaginal Inoculation with Chlamydia muridarum.
- Author
-
Tang, Lingli, Zhang, Hongbo, Lei, Lei, Gong, Siqi, Zhou, Zhiguang, Baseman, Joel, and Zhong, Guangming
- Subjects
- *
OVIDUCT diseases , *CHLAMYDIA trachomatis , *VAGINAL diseases , *VIRAL replication , *LABORATORY mice , *EPITHELIAL cells , *PREVENTION - Abstract
Intravaginal infection with C. muridarum in mice often results in hydrosalpinx similar to that found in women urogenitally infected with C. trachomatis, making the C. muridarum lower genital tract infection murine model suitable for studying C. trachomatis pathogenesis. To our surprise, DBA1/j mice were highly resistant to hydrosalpinx following an intravaginal infection with C. muridarum although these mice were as susceptible to lower genital tract infection as other mouse strains. A significantly lower level of C. muridarum organisms was recovered from the oviduct of DBA1/j mice, correlating the resistance to hydrosalpinx with reduced ascension of C. muridarum to the oviduct. The DBA1/j resistance to hydrosalpinx was effectively overcome by intracervical inoculation with C. muridarum. The intracervically inoculated DBA1/j mice developed severe hydrosalpinx with the highest levels of live C. muridarum organisms recovered from uterine tissue on day 3 and oviduct tissue on day 7 post inoculation while in intravaginally inoculated DBA1/j mice, the peak of live organism recovery from uterine tissue was delayed to day 7 with no rise in the amount of live organisms recovered from the oviduct. These observations have not only validated the correlation between hydrosalpinx and live organism invasion in the oviduct but also demonstrated that the intracervical inoculation, by promoting rapid chlamydial replication in the uterine epithelial cells and ascension to the oviduct of DBA1/j mice, may be used for further understanding chlamydial pathogenic mechanisms. The above findings also suggest that strategies aimed at reducing tubal infection may be most effective in blocking tubal pathology. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
37. TaMFT-A1 is associated with seed germination sensitive to temperature in winter wheat.
- Author
-
Lei L, Zhu X, Wang S, Zhu M, Carver BF, and Yan L
- Subjects
- Germination genetics, Plant Proteins genetics, Seasons, Temperature, Triticum genetics, Germination physiology, Plant Proteins metabolism, Triticum metabolism, Triticum physiology
- Abstract
The ability of seed to germinate under favorable environmental conditions is critical for seedling emergence, plant establishment, subsequent development and growth of adult plants, and it is controlled by internal genetic factors and external environmental factors. Winter wheat in the southern Great Plains is often planted six weeks before the optimal planting date to produce more biomass for cattle grazing during the winter season. A high seed germination rate in this higher soil temperature environment is required for this specific management system. In this study, a major QTL for temperature-sensitive germination was mapped on the short arm of chromosome 3A (QTsg.osu-3A) in a RIL population generated from two winter wheat cultivars. Furthermore, TaMFT-A1, previously reported to regulate seed dormancy and pre-harvest sprouting in spring wheat cultivars, was mapped tightly associated with the peak of QTsg.osu-3A. However, allelic variation in TaMFT-A1 between the two winter wheat cultivars differed from that was observed in spring wheat cultivars. There were 87 SNPs (single nucleotide polymorphisms) and 12 indels (insertions/deletions) in TaMFT-A1 between the Jagger allele for high germination and the 2174 allele for low germination in the after-ripened seeds, in comparison with 2 SNPs between the two alleles for differential pre-harvest sprouting in spring wheat cultivars. The Jagger TaMFT-A1 allele is a novel haplotype and appears extensively in winter wheat cultivars. TaMFT-A1 transcript levels were up-regulated by high temperature but down-regulated by low temperature or seed storage time. These findings suggest that TaMFT-A1 may invoke different mechanisms for controlling seed dormancy/germination among winter wheat cultivars.
- Published
- 2013
- Full Text
- View/download PDF
38. Oviduct infection and hydrosalpinx in DBA1/j mice is induced by intracervical but not intravaginal inoculation with Chlamydia muridarum.
- Author
-
Tang L, Zhang H, Lei L, Gong S, Zhou Z, Baseman J, and Zhong G
- Subjects
- Animals, Cervix Uteri pathology, Chlamydia Infections microbiology, Chlamydia muridarum physiology, Disease Models, Animal, Fallopian Tube Diseases pathology, Fallopian Tubes pathology, Female, HeLa Cells, Humans, Mice, Mice, Inbred C57BL, Mice, Inbred DBA, Reproductive Tract Infections pathology, Vagina pathology, Cervix Uteri microbiology, Chlamydia Infections pathology, Fallopian Tube Diseases microbiology, Fallopian Tubes microbiology, Reproductive Tract Infections microbiology, Vagina microbiology
- Abstract
Intravaginal infection with C. muridarum in mice often results in hydrosalpinx similar to that found in women urogenitally infected with C. trachomatis, making the C. muridarum lower genital tract infection murine model suitable for studying C. trachomatis pathogenesis. To our surprise, DBA1/j mice were highly resistant to hydrosalpinx following an intravaginal infection with C. muridarum although these mice were as susceptible to lower genital tract infection as other mouse strains. A significantly lower level of C. muridarum organisms was recovered from the oviduct of DBA1/j mice, correlating the resistance to hydrosalpinx with reduced ascension of C. muridarum to the oviduct. The DBA1/j resistance to hydrosalpinx was effectively overcome by intracervical inoculation with C. muridarum. The intracervically inoculated DBA1/j mice developed severe hydrosalpinx with the highest levels of live C. muridarum organisms recovered from uterine tissue on day 3 and oviduct tissue on day 7 post inoculation while in intravaginally inoculated DBA1/j mice, the peak of live organism recovery from uterine tissue was delayed to day 7 with no rise in the amount of live organisms recovered from the oviduct. These observations have not only validated the correlation between hydrosalpinx and live organism invasion in the oviduct but also demonstrated that the intracervical inoculation, by promoting rapid chlamydial replication in the uterine epithelial cells and ascension to the oviduct of DBA1/j mice, may be used for further understanding chlamydial pathogenic mechanisms. The above findings also suggest that strategies aimed at reducing tubal infection may be most effective in blocking tubal pathology.
- Published
- 2013
- Full Text
- View/download PDF
39. Chlamydia trachomatis GlgA is secreted into host cell cytoplasm.
- Author
-
Lu C, Lei L, Peng B, Tang L, Ding H, Gong S, Li Z, Wu Y, and Zhong G
- Subjects
- Bacterial Proteins genetics, Blotting, Western, Chlamydia trachomatis metabolism, Enzyme-Linked Immunosorbent Assay, Fluorescent Antibody Technique, Glycogen, Glycogen Synthase genetics, HeLa Cells, Humans, Bacterial Proteins metabolism, Chlamydia trachomatis enzymology, Glycogen Synthase metabolism
- Abstract
Glycogen has been localized both inside and outside Chlamydia trachomatis organisms. We now report that C. trachomatis glycogen synthase (GlgA) was detected in both chlamydial organism-associated and -free forms. The organism-free GlgA molecules were localized both in the lumen of chlamydial inclusions and in the cytosol of host cells. The cytosolic GlgA displayed a distribution pattern similar to that of a known C. trachomatis-secreted protease, CPAF. The detection of GlgA was specific since the anti-GlgA antibody labeling was only removed by preabsorption with GlgA but not CPAF fusion proteins. GlgA was detectable at 12h and its localization into host cell cytosol only became apparent at 24h after infection. The cytosolic localization of GlgA was conserved among all C. trachomatis serovars. However, the significance of the GlgA secretion into host cell cytoplasm remains unclear since, while expression of chlamydial GlgA in HeLa cells increased glycogen stores, it did not affect a subsequent infection with C. trachomatis. Similar to several other C. trachomatis-secreted proteins, GlgA is immunogenic in women urogenitally infected with C. trachomatis, suggesting that GlgA is expressed and may be secreted into host cell cytosol during C. trachomatis infection in humans. These findings have provided important information for further understanding C. trachomatis pathogenic mechanisms.
- Published
- 2013
- Full Text
- View/download PDF
40. Identification of a novel nuclear localization signal sequence in Chlamydia trachomatis-secreted hypothetical protein CT311.
- Author
-
Lei L, Dong X, Li Z, and Zhong G
- Subjects
- Active Transport, Cell Nucleus, Amino Acid Sequence, Bacterial Proteins chemistry, Cell Nucleus metabolism, HeLa Cells, Host-Pathogen Interactions, Humans, Molecular Sequence Data, Nuclear Localization Signals, Peptide Mapping, Bacterial Proteins metabolism, Chlamydia trachomatis metabolism
- Abstract
We previously reported that Chlamydia trachomatis hypothetical protein CT311 was secreted out of chlamydial inclusion and into host cell cytosol. We now found that CT311 further entered host cell nucleus at the late stage of infection and continued to accumulate in the nucleus of C. trachomatis-infected cells. When CT311 was expressed via a transgene in mammalian cells, CT311 protein was exclusively detected in the nucleus, suggesting that CT311 by itself is sufficient for nuclear targeting. However, preexisting nuclear CT311 did not affect subsequent chlamydial infection. Using deletion constructs, we mapped a nuclear localization signal sequence of CT311 to residues 21 to 63 ((21)AVEGKPLSRAAQLRERRKDLHVSGKPSPRYALKKRALEAKKNK(63)). This sequence was sufficient for targeting a heterologous protein into mammalian cell nucleus and it contains two independent clusters of basic residues ((34)RERRK(38) and (53)KKRALEAKKNK(63) respectively). Deletion or alanine substitution of the basic residues in either cluster led to loss of nuclear targeting activity, suggesting that both clusters are critical for the nuclear targeting function. These observations have demonstrated that the hypothetical protein CT311 possesses a novel nuclear localization signal sequence with dual modules of basic residues for targeting host cell nucleus during Chlamydia trachomatis infection.
- Published
- 2013
- Full Text
- View/download PDF
41. RBMS3 at 3p24 inhibits nasopharyngeal carcinoma development via inhibiting cell proliferation, angiogenesis, and inducing apoptosis.
- Author
-
Chen J, Kwong DL, Zhu CL, Chen LL, Dong SS, Zhang LY, Tian J, Qi CB, Cao TT, Wong AM, Kong KL, Li Y, Liu M, Fu L, and Guan XY
- Subjects
- Adult, Aged, Apoptosis, Carcinoma, Cell Cycle, Cell Line, Tumor, Cell Proliferation, Cell Transformation, Neoplastic, Down-Regulation, Female, Gene Deletion, Gene Expression Profiling, Gene Silencing, Genes, Tumor Suppressor, Humans, Male, Microcirculation, Middle Aged, Nasopharyngeal Carcinoma, Nasopharyngeal Neoplasms pathology, Neovascularization, Pathologic, RNA-Binding Proteins metabolism, Trans-Activators metabolism, Chromosomes, Human, Pair 3, Nasopharyngeal Neoplasms metabolism, RNA-Binding Proteins physiology, Trans-Activators physiology
- Abstract
Deletion of the short arm of chromosome 3 is one of the most frequent genetic alterations in many solid tumors including nasopharyngeal carcinoma (NPC), suggesting the existence of one or more tumor suppressor genes (TSGs) within the frequently deleted region. A putative TSG RBMS3 (RNA binding motif, single stranded interacting protein 3), located at 3p24-p23, has been identified in our previous study. Here, we reported that downregulation of RBMS3 was detected in 3/3 NPC cell lines and 13/15 (86.7%) primary NPC tissues. Functional studies using both overexpression and suppression systems demonstrated that RBMS3 has a strong tumor suppressive role in NPC. The tumor suppressive mechanism of RBMS3 was associated with its role in cell cycle arrest at the G1/S checkpoint by upregulating p53 and p21, downregulating cyclin E and CDK2, and the subsequent inhibition of Rb-ser780. Further analysis demonstrated that RBMS3 had a pro-apoptotic role in a mitochondrial-dependent manner via activation of caspase-9 and PARP. Finally, RBMS3 inhibited microvessel formation, which may be mediated by down-regulation of MMP2 and β-catenin and inactivation of its downstream targets, including cyclin-D1, c-Myc, MMP7, and MMP9. Taken together, our findings define a function for RBMS3 as an important tumor suppressor gene in NPC.
- Published
- 2012
- Full Text
- View/download PDF
42. Identification of a novel gene for biosynthesis of a bacteroid-specific electron carrier menaquinone.
- Author
-
Xie F, Cheng G, Xu H, Wang Z, Lei L, and Li Y
- Subjects
- Astragalus Plant growth & development, Astragalus Plant microbiology, Chromatography, High Pressure Liquid, Cloning, Molecular, Gene Expression Regulation, Bacterial, Genetic Complementation Test, Mass Spectrometry, Methylation, Methyltransferases metabolism, Molecular Sequence Data, Mutation genetics, Phenotype, Real-Time Polymerase Chain Reaction, Root Nodules, Plant cytology, Root Nodules, Plant microbiology, Root Nodules, Plant ultrastructure, Sequence Analysis, DNA, Species Specificity, Symbiosis genetics, Ubiquinone metabolism, Vitamin K 2 chemistry, Biosynthetic Pathways genetics, Electrons, Genes, Bacterial genetics, Mesorhizobium genetics, Vitamin K 2 metabolism
- Abstract
Ubiquinone (UQ) has been considered as an electron mediator in electron transfer that generates ATP in Rhizobium under both free-living and symbiosis conditions. When mutated, the dmtH gene has a symbiotic phenotype of forming ineffective nodules on Astragalus sinicus. The gene was isolated from a Mesorhizobium huakuii 7653R transposon-inserted mutant library. The DNA sequence and conserved protein domain analyses revealed that dmtH encodes demethylmenaquinone (DMK) methyltransferase, which catalyzes the terminal step of menaquinone (MK) biosynthesis. Comparative analysis indicated that dmtH homologs were present in only a few Rhizobia. Real-time quantitative PCR showed dmtH is a bacteroid-specific gene. The highest expression was seen at 25 days after inoculation of strain 7653R. Gene disruption and complementation tests demonstrated that the dmtH gene was essential for bacteroid development and symbiotic nitrogen fixation ability. MK and UQ were extracted from the wild type strain 7653R and mutant strain HK116. MK-7 was accumulated under microaerobic condition and UQ-10 was accumulated under aerobic condition in M. huakuii 7653R. The predicted function of DmtH protein was confirmed by the measurement of methyltransferase activity in vitro. These results revealed that MK-7 was used as an electron carrier instead of UQ in M. huakuii 7653R bacteroids.
- Published
- 2011
- Full Text
- View/download PDF
43. Characterization of the specific CD4+ T cell response against the F protein during chronic hepatitis C virus infection.
- Author
-
Gao DY, Jin GD, Yao BL, Zhang DH, Gu LL, Lu ZM, Gong Q, Lone YC, Deng Q, and Zhang XX
- Subjects
- Amino Acid Sequence, Animals, Epitopes chemistry, HLA Antigens metabolism, Humans, Interferon-gamma metabolism, Leukocytes, Mononuclear metabolism, Mice, Mice, Transgenic, Molecular Sequence Data, Spleen cytology, CD4-Positive T-Lymphocytes metabolism, Hepacivirus metabolism, Hepatitis C virology, Viral Fusion Proteins metabolism
- Abstract
Background: The hepatitis C virus (HCV) Alternate Reading Frame Protein (ARFP or F protein) presents a double-frame shift product of the HCV core gene. We and others have previously reported that the specific antibodies against the F protein could be raised in the sera of HCV chronically infected patients. However, the specific CD4(+) T cell responses against the F protein during HCV infection and the pathological implications remained unclear. In the current study, we screened the MHC class II-presenting epitopes of the F protein through HLA-transgenic mouse models and eventually validated the specific CD4(+) T cell responses in HCV chronically infected patients., Methodology: DNA vaccination in HLA-DR1 and-DP4 transgenic mouse models, proliferation assay to test the F protein specific T cell response, genotyping of Chronic HCV patients and testing the F-peptide stimulated T cell response in the peripheral blood mononuclear cell (PBMC) by in vitro expansion and interferon (IFN)- γ intracellular staining., Principal Findings: At least three peptides within HCV F protein were identified as HLA-DR or HLA-DP4 presenting epitopes by the proliferation assays in mouse models. Further study with human PBMCs evidenced the specific CD4(+) T cell responses against HCV F protein as well in patients chronically infected with HCV., Conclusion: The current study provided the evidence for the first time that HCV F protein could elicit specific CD4(+) T cell response, which may provide an insight into the immunopathogenesis during HCV chronic infection.
- Published
- 2010
- Full Text
- View/download PDF
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