Construction of fluorescent fusion expression vector for rat LC3B and its application of autophagy detection in Osteosarcoma cells / 中华骨科杂志

Objective To monitor the autophagy in osteosarcoma cells by constructing three rLC3B fusion expression vectors,respectively.Methods Rat LC3B gene sequence was amplified by PCR and cloned into pEGFP-C 1 and pmCherry-C1 to construct the fusion expression vector of pEGFP-rLC3B and pmCherry-rLC3B.Subsequently,the EGFP-rLC3B sequence was obtained by PCR with the pEGFP-rLC3B as a template,and cloned into pmCherry-C 1,so the pmCherry-EGFP-rLC3B fusion expression vector was constructed.Three plasmids were transfected into U-2OS cells,and the starvation or Rapamycin was adopted to induce autophagy or the chloroquine or Baf-A1 was used to inhibit autophagy,to verify the above plasmids' function in autophagy detection by laser scanning confocal microscopy.Western blot was used to detect the endogenous LC3B and exogenous EGFPrLC3B,pmCherry-rLC3B and mCherry-EGFP-rLC3B,and to verify the correct expression of exogenous rLC3B and their function of autophagy detection.Finally,cleaved free EGFP was detected by western blot to evaluate the level of autophagic degradation.Results Three fusion expression vectors were constructed successfully through sequencing and restriction enzyme digestion validation.The starvation or Rapamycin was adopted to induce autophagy or the chloroquine or Baf-A 1 was used to inhibit autophagy in transfected U-2OS cells.Clear autophagosomes and autolysosomes were observed by laser scanning confocal microscopy.Endogenous LC3B and exogenous EGFP-rLC3B,pmCherry-rLC3B and mCherry-EGFP-rLC3B were detected through western blot.Finally,western blot verified that the expression of cleaved free EGFP was significantly up-regulated with the increase of starvation time.12 h group increased 1.05 times than the control group and 24 h group increased 1.56 times,showing that the levels of autophagic degradation increased.Conclusion EGFP-rLC3B can be used to detect autophagosome and evaluate the level of autophagic degradation.mCherry-rLC3B can be used to detect autophagosome and autolysosome,but can't distinguish autophagosome from autolysosome.The pmCherry-EGFP-rLC3B has an advantage in the detection of autophagic flux which can distinguish autophagosome from autolysosome.

Clonación de secuencias de alfavirus y flavivirus para su uso como controles positivos en el diagnóstico molecular / Cloning alphavirus and flavivirus sequences for use as positive controls in molecular diagnostics

RESUMEN El objetivo de la investigación fue obtener controles positivos para la validación de técnicas moleculares (RT-PCR) utilizadas en diagnóstico e investigación de infecciones virales. A partir de cepas de CHIKV, Zika, DENV-1, DENV-2, DENV-3 y DENV-4, se extrajeron ARN virales para obtener por RT-PCR los ADN complementarios (ADNc) de las secuencias nsP4 (CHIKV), NS5 (virus Zika), C/prM-M y 5´UTR-C (DENV-1, DENV-2, DENV-3, DENV-4) que fueron clonados en pGEM®-T Easy. La clonación se confirmó mediante PCR de colonias, de las cuales se extrajo el ADN plasmídico para la verificación de la clonación de los fragmentos. Se logró la clonación de ADNc correspondientes a nsP4, NS5, C/prM-M y 5´UTR-C de los distintos agentes virales. En conclusión se obtuvieron los plásmidos recombinantes con cada una de las secuencias especificadas para su posterior valoración como controles positivos en técnicas moleculares, evitando el uso de cultivos celulares que pueden resultar costosos, laboriosos y potencialmente peligrosos.

ABSTRACT The purpose of the study was to obtain a positive control to validate molecular techniques (reverse transcription- polymerase chain reaction [RT-PCR]) used in the diagnosis and research of viral infections. From strains of Chikungunya virus (CHIKV), Zika virus, and Dengue virus (DENV-1, DENV-2, DENV- 3, and DENV-4) viral RNAs were extracted to obtain complementary DNA using RT-PCR from the nsP4 (CHIKV), NS5 (Zika virus), C/prM-M, and 5′UTR-C (DENV-1, DENV-2, DENV-3, DENV-4) sequences, which were cloned into pGEM®-T Easy. Cloning was confirmed through colony PCR, from which plasmid DNA was extracted for fragment cloning verification. Cloning of cDNA corresponding to nsP4, NS5, C/prM-M, and 5′UTR-C of the different viral agents was achieved. In conclusion, recombinant plasmids were obtained with each of the sequences specified for further assessment as positive controls in molecular techniques in an effort to avoid the use of cell cultures, which can be costly, time-consuming, and potentially dangerous.

Bacterial diversity of symptomatic primary endodontic infection by clonal analysis

Abstract The aim of this study was to explore the bacterial diversity of 10 root canals with acute apical abscess using clonal analysis. Samples were collected from 10 patients and submitted to bacterial DNA isolation, 16S rRNA gene amplification, cloning, and sequencing. A bacterial genomic library was constructed and bacterial diversity was estimated. The mean number of taxa per canal was 15, ranging from 11 to 21. A total of 689 clones were analyzed and 76 phylotypes identified, of which 47 (61.84%) were different species and 29 (38.15%) were taxa reported as yet-uncultivable or as yet-uncharacterized species. Prevotella spp., Fusobacterium nucleatum, Filifactor alocis, and Peptostreptococcus stomatis were the most frequently detected species, followed by Dialister invisus, Phocaeicola abscessus, the uncharacterized Lachnospiraceae oral clone, Porphyromonas spp., and Parvimonas micra. Eight phyla were detected and the most frequently identified taxa belonged to the phylum Firmicutes (43.5%), followed by Bacteroidetes (22.5%) and Proteobacteria (13.2%). No species was detected in all studied samples and some species were identified in only one case. It was concluded that acute primary endodontic infection is characterized by wide bacterial diversity and a high intersubject variability was observed. Anaerobic Gram-negative bacteria belonging to the phylum Firmicutes, followed by Bacteroidetes, were the most frequently detected microorganisms.

Polymorphic membrane protein I of Chlamydia trachomatis：prokaryotic expression, purification, antibody preparation and identification / 中华皮肤科杂志

Objective To clone and express the polymorphic membrane protein I(PmpI)gene of Chlamydia trachomatis(Ct), and to assess the immunogenicity and biological characteristics of PmpI. Methods A bioinformatic software was used to analyze the sequence of the PmpI gene of Ct, and to predict B cell epitopes in PmpI. With Ct serovar D DNA as the template, PCR was performed to amplify the N?terminal region(from position 90 to 1464)of the PmpI gene, which was cloned into a prokaryotic expression vector pET28a to express the recombinant protein PmpI. A Ni?ion affinity chromatography column was used to purify the recombinant protein, which was used to immunize New Zealand rabbits for preparation of polyclonal antibodies. Western blot analysis was conducted to evaluate the immunogenicity of this protein. Results A comprehensive analysis was carried out on the secondary structure, flexible regions, hydrophilicity plot, antigenic index and surface probability plot of the protein, which suggested that PmpI had 8 dominant B?cell epitopes. The product of PCR targeting the PmpI gene of Ct serovar D showed a total length of 1 375 bp. The recombinant prokaryotic expression vector pET28a?PmpI was successfully constructed. A recombi?nant protein with a relative molecular mass of approximately 50 000 was successfully expressed after isopropylβ?d?1?thiogalactopyranoside (IPTG) induction, and purified by affinity chromatography. Polyclonal antibodies against the recombinant protein were successfully prepared. Conclusion The N?PmpI protein of Ct serovar D is cloned and expressed successfully, laying a foundation for further studies on its biological functions.

Expression of GRP78 in the radiated survival subclones of nasopharyngeal carcinoma C666-1 cells / 中国医师杂志

Objective To investigate radio-sensitivity and expression of GRP78 protein in the survival subclones of nasopharyngeal carcinoma (NPC) C666-1 cells.Methods NPC C666-1 cells were first irradiated with X-ray at a large dose of 8Gy.Three survival subclones were selected and named as C666-1-R1, C666-1-R2, and C666-1-R3.The radio-sensitivity was analyzed for the radiated survival subclones and their parent control C666-1 cells with Methyl Thiazolyl Tetrazolium assay(MTT) and Trypan blue dye methods.The expression of GRP78 was analyzed for three survival subclones and control C666-1 with Western blot.Results After 6 Gy irradiation, the cell survival rate of three subclones was higher than that of the control cells, especially a significant difference for C666-1-R2 cells (P ＜ 0.05), which suggested a radioresistance in C666-1-R2 cells.Moreover, GRP78 expression in each subclone was significantly higher than that of parent C666-1 cells (P ＜ 0.05).Conclusions The irradiated-survival subclone C666-1-R2 was radio-resistant.GRP78 was overexpressed in the irradiated-survival subclones.GRP78 might be an ideal target for treatment of a nasopharyngeal carcinoma.

Cloning and prokaryotic expression of human Cyclin D1 gene / 中国医师杂志

Objective To obtain the Cyclin D1 through cloning and prokaryotic expression of Cyclin D 1 gene.Methods The total RNA was extracted from liver cancer tissue .The Cyclin D1 cDNA was obtained by reverse transcriptase polymerase chain reaction (RT-PCR).The Cyclin D1 cDNA was sequenced, and sub-cloned to the PET32a+.The prokaryotic expressed was used to obtain the Cyclin D1.Results The 483 bp Cyclin D1 cDNA was obtained.The sequence of Cyclin D1 was corrected.The 36 KD CyclinD1 was obtained by prokaryotic expression .Conclusions The Cyclin D1 cDNA was obtained.Cyclin D1 was expressed in BL21.

Cloning and characterization of the heavy chain variable region gene of monoclonal antibody 2F2 against Japanese encephalitis virus / 中国医师杂志

Objective To obtain the heavy chain variable region (VH) gene of monoclonal antibody 2F2 against Japanese encephalitis virus (JEV).Methods Total RNA was isolated with Trizol from hybridoma 2F2 cells,and cDNA of VH was amplified with reverse transcription polymerase chain reaction (RT-PCR) and sequenced.The putative VH gene was expressed in E.coli,and the expressed products was detected with enzyme linked immunosorbent assay (ELISA) to determine the activity to bind JEV.Results The VH gene was 354 bp in length which encodes 118 amino acids.Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the VH gene was successfully expressed and purified from inclusion bodies.ELISA result also demonstrated that VH gene expressed products bind purified JEV.Conclusions The VH gene of monoclonal antibody 2F2 against JEV had been cloned.

Bioterrorismo e a facilidade de acesso à biotecnologia e seus insumos / Bioterrorism and easy access to biotechnology and its inputs

Os fundamentalismos surgiram no Ocidente a partir de questões religiosas e posteriormente difundiram-se para outras partes do mundo tomando outras conotações, principalmente políticas. As técnicas de manipulação genética difundiram-se pelas universidades, que formam mestres e doutores com os conhecimentos básicos sobre clonagem gênica, que se tornou de domínio público. Todos os insumos para clonagem gênica podem ser adquiridos por meio de catálogos via internet. Podem-se recrutar profissionais fanáticos e com a competência para a manipulação genética de organismos patogênicos, lado perverso da biotecnologia. Os conflitos étnicos, culturais e religiosos estão associados a um cenário de contrastes entre os países ricos e carentes de matéria-prima e aqueles pobres, mas detentores de insumos básicos e energia, e atingem a sua forma mais aguda nos fundamentalismos. Grupos de fanáticos têm pleno acesso a essa biotecnologia. Estariam assim as populações civis vulneráveis aos ataques do bioterrorismo com armas biológicas geneticamente modificadas?.

Fundamentalism arose in the West based in religious matters and afterward diffused to other parts of theworld with other connotations, especially political. Genetic manipulation techniques spread to universities,which has given masters and doctors the basic knowledge on gene cloning, which has become public domain.All inputs for gene cloning may be obtained through online catalogs. Fanatic professionals may be recruited,with qualification for genetic manipulation of pathogenic organisms, the negative side of biotechnology. Eth-nic, cultural and religious conflicts are linked to a series of contrasts between countries that are rich but witha lack of raw materials and the poor countries that possess basic input and energy sources, when it reachesthe highest fundamentalist form. Fanatic groups have complete access to this biotechnology. Are civilian po-pulations in vulnerable to bioterrorist attacks involving genetically modified biological weapons?

Gene cloning and expression of the Tp0453 antigen immuno-dominant epitope fragment of Treponema pallidum and its potential use in serodiagnosis of syphilis / 中华传染病杂志

Objective To clone and express the Tp0453 antigen immuno-dominant epitope fragment of Treponema pallidum (Tp) in Escherichia coli,in an effort to develop serological tests with increased specificity for the diagnosis of syphilis.Methods The gene encoding Tp0453 recombinant outer membrane protein fragment was amplified by polymerase chain reaction (PCR),and inserted into expression vector pQE30 after T-A cloning,then confirmed by restriction map.The constructed recombinant plasmid pQE30-Tp0453 was transformed to E.coli M15 for expression induced by isopropyl β-D-1-thiogalactopyranoside.The expressed product was identified by Western blot,and purified by Ni2+-NTA agarose column chromatography.A double antigen sandwich enzymelinked immunosorbent assays (ELISA) was established by using the recombinant Tp0453 protein to test sera from 48 patients with positive Treponema pallidum particle agglutination test (TPPA),and 40 negative sera as control.Results The PCR amplicon of the target gene was about 490 bp.The recombinant plasmid pQE30-Tp0453 was correctly constructed and successfully expressed in E.coli M15.The expressed product,with a relative molecular of about 21 000,existed in a form of inclusion body,accounting for about 18％ of total somatic protein,and reached a purity of more than 95％ after purification.Western blot showed specific reaction of the expressed protein with Tp positive serum.The ELISA tests with the 88 clinical samples yielded a sensitivity of 97.9％ (47/48),and specificity of 100.0 ％ (40/40).The consistency of results between the ELISA test and the TPPA test was 98.9 ％ (87/88).Conclusion The expressed Tp0453 fragment has showed good immunoreactivity with serum from patients with syphilis,providing the foundation of further development of serological diagnostic kit with increased specificity for the diagnosis of TP infection.

Purification of bone marrow mesenchymal stem cells by a Colony-Forming system / 中国医师杂志

Objective To purify BMSCs by a simple Colony-Forming system and identify BMSCs in vitro.Methods BMSCs were planted at low-density ( 10/cm2 ) in the early stage of isolation,additional cells were scraped until a colony formed,secondly seeded those Colony-Forming cells at low-density.This process was repeat again when passaged cells formed another colony.This so called Colony-Forming selection was repeated several times until highly purified cells were obtained.Biological characters of BMSCs were observed.The surface antigens of BMSCs were identified by flow cytometry.The multipotentiality of BMSCs was assayed for differentiation into either osteoblasts or adipocytes.Results Homogeneous cells were obtained after BMSCs were passaged twice to thrice by Colony-Forming system.These BMSCs highly expressed positive surface antigens of BMSCs ( CD29 in 98.8％,CD90 in 98.4％ ) meanwhile seldom expressed negative surface antigens of BMSCs (CD31 in 2.6％,CD45 in 3％ ).BMSCs efficiently differentiated into osteoblasts and adipocytes.Conclusions Colony-Forming system is a simple and effective way to get highly purified BMSCs in a short time.

Selection of the treatment strategies of myelodysplastic syndromes based on clone category / 白血病·淋巴瘤

Myelodysplastic syndromes(MDS) are heterogeneous clonal stem cell disorders.There are about 40 ％-60 ％ MDS patients with abnormal karyotype.To analyze the clone category is not only useful for diagnosis and evaluating prognosis,but also helpful for the selection of optimal therapy strategies to improve the treatment efficacy.

Clonaje y caracterización molecular in silico de un transcrito de fosfolipasa A2 aislado del veneno de la serpiente peruana Lachesis muta / Molecular cloning and characterization in silico of phospholipase A2 transcripto isolated from Lachesis muta peruvian snake venom

Objetivo. Aislar y caracterizar in silico un transcrito del gen de fosfolipasa A2 (PLA2) aislado del veneno de Lachesis muta de la Amazonía peruana. Materiales y métodos. Se amplificó el transcrito del gen sPLA2 mediante la técnica de RT-PCR a partir de RNA total utilizando cebadores específicos, el producto de DNA amplificado se insertó en el vector pGEM para su posterior secuenciación. Mediante análisis bioinformático de la secuencia nucleotídica se determinó un marco de lectura abierta de 414 nucleótidos que codifica 138 aminoácidos, incluyendo16 aminoácidos del péptido señal, el peso molecular y el pI fueron de 13 976 kDa y 5,66 respectivamente. Resultados. La secuencia aminoacídica denominada Lm-PLA2- Perú, contiene Asp49, así como Tyr-28, Gly-30, Gly-32, His-48, Tyr52, Asp99 importantes para la actividad enzimática. La comparación de Lm-PLA2-Perú con las secuencias aminoacídicas de los bancos de datos mostró 93 por ciento de similitud con las sPLA2 de Lachesis stenophrys y más del 80 por ciento con otras sPLA2 de venenos de la familia Viperidae. El análisis filogenético de la secuencia nucleotídica del transcrito del gen sPLA2 indica que Lm-PLA2-Perú se agrupa con otras sPLA2 [Asp49] ácidas previamente aisladas del veneno de Bothriechis schlegelii con un 89 por ciento de identidad. El modelaje tridimensional de Lm-PLA2-Perú, presenta una estructura característica de sPLA2 del Grupo II formada por tres hélices-α, una lámina-β, una hélice corta y un lazo de unión con calcio. Conclusión. La secuencia nucleotídica corresponde al primer transcripto del gen de PLA2 clonado a partir del veneno de la serpiente Lachesis muta, que habita en la selva del Perú.

Objective. Isolate and characterize in silico gene phospholipase A2 (PLA2) isolated from Lachesis muta venom of the Peruvian Amazon. Material and methods. Technique RT-PCR from total RNA was using specific primers, the amplified DNA product was inserted into the pGEM vector for subsequent sequencing. By bioinformatic analysis identified an open reading frame of 414 nucleotides that encoded 138 amino acids including a signal peptide of 16 aminoacids, molecular weight and pI were 13 976 kDa and 5.66 respectively. Results. The aminoacid sequence was called Lm-PLA2-Peru, contains an aspartate at position 49, this aminoacid in conjunction with other conserved residues such as Tyr-28, Gly-30, Gly-32, His-48, Tyr52, Asp99 are important for enzymatic activity. The comparison with the amino acid sequence data banks showed of similarity between PLA2 from Lachesis stenophrys (93 percent) and other PLA2 snake venoms and over 80 percent of other sPLA2 family Viperidae venoms. A phylogenetic analysis showed that Lm-PLA2-Peru grouped with other acidic [Asp49] sPLA2 previously isolated from Bothriechis schlegelii venom showing 89 percent nucleotide sequence identity. Finally, the computer modeling indicated that enzyme had the characteristic structure of sPLA2 group II that consisted of three α-helices, a β-wing, a short helix and a calcium-binding loop. Conclusion. The nucleotide sequence corresponding to the first transcript of gene from PLA2 cloned of Lachesis muta venom, snake from the Peruvian rainforest.

Screening for specific membrane protein of Schistosoma japonicum and cloning of sequence encoding protein sj15 / 第二军医大学学报

Objective: To screen for the potential specific membrane protein from the protein database built by our Lab and to clone the encoding sequence of a potential immunoprotective protein according to the screening result, so as to search for new vaccine candidate or drug targets for Schistosomiasis control. Methods: The related data were retrieved using the key words "Schistosoma japonicum" and "membrane or tegument" from the NCBI database to construct local database of membrane protein of S. japonicum. The specific membrane proteins were screened by multi-alignment with the protein sequences from our local database of Schistosoma mansoni, Homo sapiens, Rattus norvegicus and Mus musculus. Meanwhile, the character and function of the predicted membrane protein were analyzed with public software in the website CBS. The specific primer for the sequence of the predicted protein with potential immuno-protective function were designed and synthetized; the coding sequence was then amplified from the adult worm of S. japonicum by PCIZ and was cloned into rokaryotic expression vector pGEX-4T-1. Results: A total of 153 predicted membrane protein of S. japonicum were retrieved and 28 potentially specific for S. japonicum were screened out. The coding sequence of the predicted protein, with a relative molecular weight of about 15 000, was successfully amplified from the adult worm of S. japonicum and was temporarily named gene sj15; the recombinant plasmid pGEX-4T-1-sjl5 was also successfully constructed. Conclusion: Many specific membrane proteins of S. japonicum have been successfully screened out. The predicted sjl5 gene (announced as AY223457 in GenBank) has been successfully cloned, proving the existence of sj15 gene in adult worm of S. japonicum. The prokaryotic expression vector pGEX-4T-1 for sj15 has also been successfully constructed, providing a foundation for further study of sj15 function.

Expression of Recombinant Human Thyroid Stimulating Hormone Subunit α in Escherichia Coli / 天津医药

Objective:To construct pGEX-3X/hTSHa Escherichia coli(E.coli)expression system and prepare purified recombinant GST-recombinant human thyroid stimulating hormone(rhTSH)α protein.Methods:The complete coding sequence of hTSHα was obtained by RT-PCR with total RNA extracted from fresh chorial tissue as the template,and thereafter cloned into expression vector pGEX-3X by EcoRl and BamHI digestion.The recombinant plasmid was transformed into E.coli Mach1-T1 and then induced expression by WrG.The GST-rhTSHα fusion protein was identified by SDS-PAGE and its antigenicity was verified by a modified competitive ELISA.Results:A specific protein band of 36 ku,in accordance with predicted molecular weight,could be visualized in SDS-PAGE.As the result of ELISA,the recombinant GST-hTSHα protein can inhibit the intact TSH molecular binding with anti-TSHα antibody in a dose dependent manner.Conclusion:The cDNA of hTSHα was cloned and the recombinant expression vector pGEX-3X/hTSHα was constructed successfully.The recombinant GST-rhTSHα protein could be highly expressed in E.coli Machl-T1 and was approved of possessing antigenicity.

Molecular cloning, sequencing and function of extracellular signal regulated kinase of Echinococcus granulosus / 中华传染病杂志

Objective To perform molecular cloning and sequencing, bioinformatics analysis,protein expression and function of extracellular signal regulated kinase (EgERK1) of Echinococcus granulosus in Xinjiang. Methods The specific primers of EgERK1 were designed and total RNA was extracted from Echinococcus granulosus in Xinjiang. EgERK1 gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and prokaryotic expression plasmid pET28a-EgERK1 was constructed and sequenced. The sequences were analyzed by DNA sequencing and bioinformatics technology. The recombinant EgERK1 protein was induced and expressed. The biological function was detected using sodium dodecyl sulfate polyacrylamide gel electropheresis and Western blot. Results The sequence of RT-PCR product was 1125 bp, encoding 374 amino acids with isoelectric point of 6.34.This gene was a new ERK-homologues gene indicated by BLAST, named EgERK1(EU701008).Homology comparisons indicated that the homology of EgERK1 and EmMPK1from Echinococcus multilocularis was 95.45%, and was 43.04%-61.88% to ERK from Caenorhabditis elegans, S. cerevisiae, D. melanogaster and human. Phylogenetic analysis showed that EgERK1 clustered with EmMPK1. Bioinformatics analysis predicted that EgERK1 contained a highly conserved T-X-Y motif and activation loop segment of ERK-like kinase.Western blot results showed the EgERK1 recombinant protein could reacted specifically with anti-human ERK monoclonal antibody. Conclusion A new EgERK1 gene of Echinococcus granulosus is successfully cloned and its recombinant protein could reacted specifically with ERK1/2 antibody, which provides the basis for further study of EgERK1 function in the host-parasite interaction.

Cloning, expression, purification and identification of Chlamydia trachomatis polymorphic membrane protein G / 中华皮肤科杂志

Objective To clone, express and purify Chlamydia trachomatis polymorphic membrane protein (Pmp G), and to identify its immunogenicity. Methods The Pmp G gene of C. trachomatis serotype E was amplified by PCR, cloned into prokaryotic expression vector PET30a (+). The positive recombinant was transformed into the bacterium E coli (BL-21), identified by enzyme digestion, PCR amplification and gene sequencing. Then, it was induced to express followed by the identification of expression product with SDS-PAGE and Western blotting. The purified protein was used to immunize BALB/C mice to test its immunogenicity. Results PCR produced a 1092 bp-sized DNA fragment, which had a sequence consistent with that of PmpG gene of C. trachomatis E type in the GenBank database. The molecular weight of expression product was 55 kD, which was proved to be the expected size, and Western Blotting confirmed it to be the specific protein. Moreover, special antibodies to PmpG were induced to be generated by mice immunized with the purified protein. Conclusions The constructed prokaryotic expression vector for PmpG is expressed successfully in E. coli, and the expression product shows immunogenicity.

Clonal analysis of endometriotic lesions using human androgen receptor gene / 中华妇产科杂志

Objective To investigate characteristics of endometriotic lesions clone with various pathological subtypes by analyzing the polymorphism of X chromosome linked human androgen receptor allele (HUMARA). Methods Eight frozen tissues of endometriotic leisons were collected from 6 patients who received laparotomy or laparoscopy surgery in Peking Union Medical College Hospital from Nov. 2008 to Jun. 2009. Fifty specimens of epithelial cells from single endometrial glands were isolated and collected from endometriotic lesions by using laser capture microdissection. HUMARA was applied as the gene marker of clonal analysis. Nested palymerase chain reaction, double-enzyme digestion reaction with two methylationsensitive restriction endonuclease (Hha Ⅰ and Hpa Ⅱ), and the automated gene sequencing technique were utilized in this study to evaluate the characteristics of endometriotic lesions clone. Results Of 50 specimens of isolated glands, 34 were informative for clonal analysis, and all of which showed monoclonality. Of 3 ovarian endometriotic tissues, one tissue of HUMARA showed unuseful information, the other 2 ovarian endometriotic tissues respectively had 4 and 7 informative specimens of gland epithelial cells, and all of the glands from each tissue showed uniform clonal pattern. Two peritoneal endometriotic tissues had 1 and 5 informative specimens from individual glands, respectively; and the clonal patterns in 5 glands from the single lesion were divergent. Two abdominal wall endometriotic tissues had 7 and 6 informative specimens,respectively; and variable clonal patterns were seen in different glands from each lesion. One deep infiltrating endometriotic lesion had 4 informative specimens of isolated glands, and all of them showed unique clonal pattern. The disparate clonal patterns were found in endometriotic lesions with variable pathological subtypes, even arising from the same patient. Conclusions The epithelial cells from individual endometriotic gland showed monoclonality , and different glands from the same endometriotic lesion might show divergent patterns.

The reliability of cloning-sequencing to detect the number of trinucleotide repeats / 中华神经科杂志

Objective Cloning-sequencing is a common method to detect the number of trinucleotide repeats.The aim of the present study is to discuss its reliability.Methods One clinically diagnosed SCA1 patient was recruited in the study.The numbers of CAG repeats in ATXN1 gene were estimated via polymerase chain reaction (PCR) and denaturing polyacrylamide gel electrophoresis (DPAGE).To verify accuracy of CAG numbers estimated, the PCR products were electrophoresed on a 2.5% agarose ge] and separated bands were excised for direct sequencing.Also, the longer separated band underwent cloning-sequencing using a TA cloning kit.Results The patient was identified as SCA1 by DPAGE.After direct sequencing, the numbers of CAG repeats were 26 and 47 in the shorter and longer bands, respectively.However, after cloning-sequencing of the longer band, there are 10 different numbers of CAG repeats, including 50, 47, 46, 41,32, 28, 27, 26, 25 and 24.Furthermore, there are other kinds of trinucleotide repeats, such as CCG, CGG, CTG, CAA and TAT scattered among the CAG repeats.Conclusions It is not reliable to identify the number of trinucleotide repeats by cloning-sequencing alone.To improve the reliability, it is better to combine cloning-sequencing with other methods.

Sequence analysis of secretory antigen P53 and immunological identification of the recombinant product of Trichinella spiralis / 中华传染病杂志

Objective To analyze the immunological characteristics of Trichinella spiralis secretory antigen P53 and to evaluate its value in diagnosis of trichinellosis. Methods An open read frame of secretory antigen P53 was cloned from Trichinella spiralis by reverse transcriptasepolymerase chain reaction (RT-PCR) and then sequenced. Bioinformatics analysis was performed to search for its homologues in other helminths and predict its potential linear B cell epitopes and T cell epitopes. The sequence coding mature peptide was inserted into prokaryotic expression vector pET28a(+) and the purified recombinant product was identified by Western blot using serum samples of patients infected with Trichinella spiralis or other helminth. Results Bioinformaties analysis results showed that there was no P53 homologue in other helminths, which indicated that there were many linear B cell epitopes and T cell epitopes in TsP53. The recombinant P53 antigen only reacted with the serum samples of patients infected with Trichinella spiralis without any cross-reaction with the serum of patients infected with other helminths. Conclusion P53 has strong immunogenicity and immunoreactivity, which may be a promising candidate for developing Trichinella spiralis specific diagnostic method.

Expression, purification of epitope peptide of human melanin-concentrating hormone receptor 1 and its antigenicity detection in vitiligo patients / 中华皮肤科杂志

Objective To express and purify the epitope peptide of human melanin-concentrating hormone receptor 1, and to evaluate its performance in the detection of autoantibodies in vitiligo patients. Methods The target gene encoding the epitope peptide of human melanin-concentrating hormone receptor 1 was synthesized, cloned to prokaryotic expression vector pGEX-4T-2 which was then transferred to E. coli BL21. The protein expression was induced by isopropy-β-D-thiogalactoside (IPTG) and identified with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot. Blocking ELISA was carried out with membrane proteins extracted from melanocytes as the blocking antigen. The antigenicity of the peptide was detected in sera from 100 patients with progressive vitiligo and 30 healthy human controls. Results The recombinant expression vector was successfully constructed, and the target protein was successfully expressed in E.coli, which was evidenced by SDS-PAGE and Western blot. With the glutathione S-transferase (GST) purification kit, the purity of the recombinant protein reached 100% when the sampling weight was less than 0.625 μg.The binding of the target protein with serum IgG antibodies from vitiligo patients could be blocked by natural membrane antigen of melanocytes. Of the 100 sera from patients with progressive vitiligo, 36 were reactive with the target protein. Conclusions The epitope peptide of human melanin-concentrating hormone receptor 1 has been successfully expressed and purified. The purified protein can bind with serum IgG antibodies from vitiligo patients, and may be applied to the detection of autoantibodies against human melanin-concentrating hormone receptor 1.