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Search Results: 1 - 10 of 36661 matches for " XIAO Peigen "
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Prediction of sites under adaptive evolution in flavin-containing monooxygenases: Selection pattern revisited
DaCheng Hao,PeiGen Xiao
Chinese Science Bulletin , 2011, DOI: 10.1007/s11434-011-4380-8
Abstract: Flavin-containing monooxygenase (FMO), like cytochrome P450 (CYP), is a monooxygenase that uses the reducing equivalents of NADPH to reduce one atom of molecular oxygen to water, while the other atom is used to oxidize the substrate. Recently, it was shown that some CYP isoforms have been subject to positive selection. However, it is unknown whether the highly conserved phase I detoxification enzyme, FMO, has undergone similar positive Darwinian selection. We used maximum-likelihood models of codon substitution, evolutionary fingerprinting, and cross species comparison to investigate the occurrence of adaptive evolution in FMO sequences. We used recent genomic data from a range of species, including vertebrates and invertebrates. We present the evidence for the occurrence of adaptive evolution in mammalian FMO 3, 4, 5, and fugu FMOs but not in mammalian FMO 1, FMO 2, frog FMOs, other fish FMOs and invertebrate FMOs. The sites under adaptive evolution were significantly associated with the insertion domain in mammalian FMO 5. We identified specific amino acid sites in FMOs 3–5 that are likely targets for selection based on the patterns of parallel amino acid change. The most likely role of adaptive evolution is the repair of mutations that permitted optimal NADP+ binding and improved catalytic efficiency. The occurrence of positive selection during the evolution of phase I detoxification enzymes such as FMOs 3–5 and fugu FMO suggests the occurrence of both high selection pressure acting on species within their unique habitats and significant changes in intensity and direction (forms of xenobiotics and drugs) resulting from changes in microhabitat and food.
Phenotype prediction of nonsynonymous single nucleotide polymorphisms in human phase II drug/xenobiotic metabolizing enzymes: perspectives on molecular evolution
DaCheng Hao,PeiGen Xiao,ShiLin Chen
Science China Life Sciences , 2010, DOI: 10.1007/s11427-010-4062-9
Abstract: Nonsynonymous single nucleotide polymorphisms (nsSNPs) in coding regions can lead to amino acid changes that might alter the protein’s function and account for susceptibility to disease and altered drug/xenobiotic response. Many nsSNPs have been found in genes encoding human phase II metabolizing enzymes; however, there is little known about the relationship between the genotype and phenotype of nsSNPs in these enzymes. We have identified 923 validated nsSNPs in 104 human phase II enzyme genes from the Ensembl genome database and the NCBI SNP database. Using PolyPhen, Panther, and SNAP algorithms, 44%–59% of nsSNPs in phase II enzyme genes were predicted to have functional impacts on protein function. Predictions largely agree with the available experimental annotations. 68% of deleterious nsSNPs were correctly predicted as damaging. This study also identified many amino acids that are likely to be functionally critical, but have not yet been studied experimentally. There was significant concordance between the predicted results of Panther and PolyPhen, and between SNAP non-neutral predictions and PolyPhen scores. Evolutionarily non-neutral (destabilizing) amino acid substitutions are thought to be the pathogenetic basis for the alteration of phase II enzyme activity and to be associated with disease susceptibility and drug/xenobiotic toxicity. Furthermore, the molecular evolutionary patterns of phase II enzymes were characterized with regards to the predicted deleterious nsSNPs.
Molecular pharmacognosy
LuQi Huang,PeiGen Xiao,LanPing Guo,WenYuan Gao
Science China Life Sciences , 2010, DOI: 10.1007/s11427-010-4006-4
Abstract: This article analyzes the background and significance of molecular pharmacognosy, including the molecular identification of medicinal raw materials, phylogenetic evolution of medicinal plants and animals, evaluation and preservation of germplasm resources for medicinal plants and animals, etiology of endangerment and protection of endangered medicinal plants and animals, biosynthesis and bioregulation of active components in medicinal plants, and characteristics and the molecular bases of top-geoherbs.
Mechanisms of arsenic trioxide induced apoptosis of human cervical cancer HeLa cells and protection by Bcl-2
Youping Deng,Chen Lin,Jie Zheng,Xiao Liang,Jieping Chen,Ming Fu,Peigen Xiao,Min Wu
Science China Life Sciences , 1999, DOI: 10.1007/BF02881582
Abstract: It was recently reported that arsenic trioxide (As2O3) can induce complete remission in patients with acute promyelocytic leukemia (APL). In this present article, the biological effect of (As2O3) on human cervical cancer HeLa cells and HeLa cells overexpressing Bcl-2 is studied. By MTT and colony forming ability assays, morphology alteration, flow cytometric analysis, DNA gel electrophoresis andin situ cell death detection (TUNEL), it was found that As2O3 inhibited the growth of HeLa cells and induced G2/M arrest and apoptosis of the cells. RT-PCR, Northern blot, Western blot analysis revealed that As2O3 induced HeLa cell apoptosis possibly via decreasing the expression of c-myc and viral genes. HeLa cells overexpressing Bcl-2 partly resist As2O3 induced apoptosis, which might be relative to preventing the cells from As2O3 caused G2/M block, downregulation of c-myc gene expression and inhibition of viral gene expression was also noted. However, it was found that As2O3 at a high concentration could also induce apoptosis of HeLa cells overexpressing Bcl-2 possibly mainly via downregulating Bcl-2 expression and slightly inhibiting viral gene expression.
The First Insight into the Tissue Specific Taxus Transcriptome via Illumina Second Generation Sequencing
Da Cheng Hao, GuangBo Ge, PeiGen Xiao, YanYan Zhang, Ling Yang
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0021220
Abstract: Background Illumina second generation sequencing is now an efficient route for generating enormous sequence collections that represent expressed genes and quantitate expression level. Taxus is a world-wide endangered gymnosperm genus and forms an important anti-cancer medicinal resource, but the large and complex genomes of Taxus have hindered the development of genomic resources. The research of its tissue-specific transcriptome is absent. There is also no study concerning the association between the plant transcriptome and metabolome with respect to the plant tissue type. Methodology/Principal Findings We performed the de novo assembly of Taxus mairei transcriptome using Illumina paired-end sequencing technology. In a single run, we produced 13,737,528 sequencing reads corresponding to 2.03 Gb total nucleotides. These reads were assembled into 36,493 unique sequences. Based on similarity search with known proteins, 23,515 Unigenes were identified to have the Blast hit with a cut-off E-value above 10?5. Furthermore, we investigated the transcriptome difference of three Taxus tissues using a tag-based digital gene expression system. We obtained a sequencing depth of over 3.15 million tags per sample and identified a large number of genes associated with tissue specific functions and taxane biosynthetic pathway. The expression of the taxane biosynthetic genes is significantly higher in the root than in the leaf and the stem, while high activity of taxane-producing pathway in the root was also revealed via metabolomic analyses. Moreover, many antisense transcripts and novel transcripts were found; clusters with similar differential expression patterns, enriched GO terms and enriched metabolic pathways with regard to the differentially expressed genes were revealed for the first time. Conclusions/Significance Our data provides the most comprehensive sequence resource available for Taxus study and will help define mechanisms of tissue specific functions and secondary metabolism in non-model plant organisms.
Two New Aryltetralin Lignans from the Roots of Dolomiaea souliei
Hua Wei,Chunnian He,Yong Peng,Sen Zhang,Xiaoguang Chen,Peigen Xiao
Molecules , 2012, DOI: 10.3390/molecules17055544
Abstract: Two new aryltetralin-type lignans, dolomiaeasin A (1) and dolomiaeasin B (2), were isolated from the roots of Dolomiaea souliei. Their structures were elucidated by means of various spectroscopic analyses. The cytotoxicities of 1 and 2 were tested by the MTT method, and both compounds showed no significant cytotoxic activities against the A549 and A2780 human cancer cell lines. This is the first time that aryltetralin-type lignans were isolated from the genus Dolomiaea.
Antitumor activity and mechanisms of action of total glycosides from aerial part of Cimicifuga dahurica targeted against hepatoma
Ze Tian, Jianyong Si, Qi Chang, Liang Zhou, Shilin Chen, Peigen Xiao, Erxi Wu
BMC Cancer , 2007, DOI: 10.1186/1471-2407-7-237
Abstract: The total glycosides from the aerial part (TGA) was extracted and its cytotoxicity was evaluated in HepG2 cells and primary cultured normal mouse hepatocytes by an MTT assay. Morphology observation, Annexin V-FITC/PI staining, cell cycle analysis and western blot were used to further elucidate the cytotoxic mechanism of TGA. Implanted mouse H22 hepatoma model was used to demonstrate the tumor growth inhibitory activity of TGA in vivo.The IC50 values of TGA in HepG2 and primary cultured normal mouse hepatocytes were 21 and 105 μg/ml, respectively. TGA induced G0/G1 cell cycle arrest at lower concentration (25 μg/ml), and triggered G2/M arrest and apoptosis at higher concentrations (50 and 100 μg/ml respectively). An increase in the ratio of Bax/Bcl-2 was implicated in TGA-induced apoptosis. In addition, TGA inhibited the growth of the implanted mouse H22 tumor in a dose-dependent manner.TGA may potentially find use as a new therapy for the treatment of hepatoma.Hepatocellular carcinoma (HCC) is the fifth most common tumor worldwide, and the incidence of HCC has been rising over the past few decades in some areas such as Europe, USA and far eastern Asian countries [1]. Despite advances in diagnosis and standard therapies such as surgery, radiation, and chemotherapy, HCC remains a formidable challenge for clinical therapy [2-5]. In the search for new cancer therapeutics with low toxicity, traditional Chinese medicines are promising candidates.The dried rhizomes of Cimicifuga dahurica (Turcz) Maxim (Ranunculaceae) have been used as cooling, detoxification, antipyretic and analgesic agents for the treatment of some types of headaches and toothaches in Chinese folk medicine and were included in the Chinese Pharmacopoeia [6]. The rhizomes are traditionally the portion of the plant used for medicinal purposes in Cimicifuga species, however the aerial part of the plant is usually discarded. Previous phytochemical studies demonstrated that both the rhizomes and the aerial par
Status Quo of Complementary and Alternative Medicine
补充和替代医学的发展现状

Zhang Yaou,Yang Mengsu,Xiao Peigen,
张雅鸥
,杨梦甦,肖培根

世界科学技术-中医药现代化 , 2002,
Abstract: Recent years,because of the change in medical models and in menu of human diseases,complementary and alternative medicine(CAM)which has been rejected by mainstream medicine,is getting popular in Western countries and gradually accepted by mainstream medicine.In the United States,the National Centre for Complementary and Alternative Medicine(NCCAM)has been established at the National Institute of Health(NIH),courses of CAM have been offered in many medical schools and universities in Western countries,advanced biotech n eology is widely used to the development of natural products of CAM and a number of research papers are emerging in famous medical journals of mainstream medicine.Responding to these changes,NCCAM has developed new models for the development of CAM products.Therefore,the FDA of the United States has amended the Food and Drug Act in accordance with the models and thus the natural products of CAM are easier to gain market than synthetic products and highly purified monomers.With its extensive public foundation CAM has been provided with a healthy environment for its further development in Western countries and a good foundation has been laid for the traditional Chinese medicine to march towards the whole wortd.
Cambogin Is Preferentially Cytotoxic to Cells Expressing PDGFR
Ze Tian, Jie Shen, Fengfei Wang, Peigen Xiao, Junshan Yang, Hetian Lei, Andrius Kazlauskas, Isaac S. Kohane, Erxi Wu
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0021370
Abstract: Platelet-derived growth factor receptors (PDGFRs) have been implicated in a wide array of human malignancies, including medulloblastoma (MB), the most common brain tumor of childhood. Although significant progress in MB biology and therapeutics has been achieved during the past decades, MB remains a horrible challenge to the physicians and researchers. Therefore, novel inhibitors targeting PDGFR signaling pathway may offer great promise for the treatment of MB. In the present study, we investigated the cytotoxicity and mechanisms of cambogin in Daoy MB cells. Our results show that cambogin triggers significant S phase cell cycle arrest and apoptosis via down regulation of cyclin A and E, and activation of caspases. More importantly, further mechanistic studies demonstrated that cambogin inhibits PDGFR signaling in Daoy and genetically defined mouse embryo fibroblast (MEF) cell lines. These results suggest that cambogin is preferentially cytotoxic to cells expressing PDGFR. Our findings may provide a novel approach by targeting PDGFR signaling against MB.
De novo characterization of the root transcriptome of a traditional Chinese medicinal plant Polygonum cuspidatum
DaCheng Hao,Pei Ma,Jun Mu,ShiLin Chen,PeiGen Xiao,Yong Peng,Li Huo,LiJia Xu,Chao Sun
Science China Life Sciences , 2012, DOI: 10.1007/s11427-012-4319-6
Abstract: Various active components have been extracted from the root of Polygonum cuspidatum. However, the genetic basis for their activity is virtually unknown. In this study, 25600002 short reads (2.3 Gb) of P. cuspidatum root transcriptome were obtained via Illumina HiSeq 2000 sequencing. A total of 86418 unigenes were assembled de novo and annotated. Twelve, 18, 60 and 54 unigenes were respectively mapped to the mevalonic acid (MVA), methyl-D-erythritol 4-phosphate (MEP), shikimate and resveratrol biosynthesis pathways, suggesting that they are involved in the biosynthesis of pharmaceutically important anthraquinone and resveratrol. Eighteen potential UDP-glycosyltransferase unigenes were identified as the candidates most likely to be involved in the biosynthesis of glycosides of secondary metabolites. Identification of relevant genes could be important in eventually increasing the yields of the medicinally useful constituents of the P. cuspidatum root. From the previously published transcriptome data of 19 non-model plant taxa, 1127 shared orthologs were identified and characterized. This information will be very useful for future functional, phylogenetic and evolutionary studies of these plants.
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