RESUMO
OBJECTIVES: Epstein-Barr virus (EBV) C promoter (Cp) hypermethylation, a crucial factor for EBV latent infection of nasopharyngeal epithelial cells, has been recognized as a promising biomarker for nasopharyngeal carcinoma (NPC) detection. In this study, we develop a novel EBV Cp methylation quantification (E-CpMQ) assay and evaluate its diagnostic performance for NPC detection. METHODS: A novel qPCR assay for simultaneous quantification of methylated- and unmethylated EBV Cp was developed by the combinational modification of MethyLight and QASM, with an innovative calibrator to improve the detection accuracy and consistency. The NP swab samples and synthetic standards were used for the analytical validation of the E-CpMQ. The diagnostic efficacy of the developed E-CpMQ assay was validated in 137 NPC patients and 137 non-NPC controls. RESULTS: The E-CpMQ assay can detect the EBV Cp methylation ratio in one reaction system under 10 copies with 100â¯% recognition specificity, which is highly correlated to pyrosequencing with a correlation coefficient over 0.99. The calibrated E-CpMQ assay reduces the coefficient of variation by an average of 55.5â¯% with a total variance of less than 0.06 units standard deviation (SD). Linear methylation ratio detection range from 4.76 to 99.01â¯%. The sensitivity and specificity of the E-CpMQ respectively are 96.4â¯% (95â¯% CI: 91.7-98.8â¯%), 89.8â¯% (95â¯% CI: 83.5-94.3â¯%). CONCLUSIONS: The developed E-CpMQ assay with a calibrator enables accurate and reproducible EBV Cp methylation ratio quantification and offers a sensitive, specific, cost-effective method for NPC early detection.
Assuntos
Infecções por Vírus Epstein-Barr , Neoplasias Nasofaríngeas , Humanos , Carcinoma Nasofaríngeo/diagnóstico , Herpesvirus Humano 4/genética , Infecções por Vírus Epstein-Barr/diagnóstico , Infecções por Vírus Epstein-Barr/genética , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias Nasofaríngeas/genética , DNA Viral/genética , Nasofaringe , Metilação de DNARESUMO
In this study, the expression profiles of miR-148a were constructed in eight different ovine tissues, including mammary gland tissue, during six different developmental periods. The effect of miR-148a on the viability, proliferation, and milk fat synthesis of ovine mammary epithelial cells (OMECs) was investigated, and the target relationship of miR-148a with two predicted target genes was verified. The expression of miR-148a exhibited obvious tissue-specific and temporal-specific patterns. miR-148a was expressed in all eight ovine tissues investigated, with the highest expression level in mammary gland tissue (p < 0.05). Additionally, miR-148a was expressed in ovine mammary gland tissue during each of the six developmental periods studied, with its highest level at peak lactation (p < 0.05). The overexpression of miR-148a increased the viability of OMECs, the number and percentage of Edu-labeled positive OMECs, and the expression levels of two cell-proliferation marker genes. miR-148a also increased the percentage of OMECs in the S phase. In contrast, transfection with an miR-148a inhibitor produced the opposite effect compared to the miR-148a mimic. These results indicate that miR-148a promotes the viability and proliferation of OMECs in Small-tailed Han sheep. The miR-148a mimic increased the triglyceride content by 37.78% (p < 0.01) and the expression levels of three milk fat synthesis marker genes in OMECs. However, the miR-148a inhibitor reduced the triglyceride level by 87.11% (p < 0.01). These results suggest that miR-148a promotes milk fat synthesis in OMECs. The dual-luciferase reporter assay showed that miR-148a reduced the luciferase activities of DNA methyltransferase 1 (DNMT1) and peroxisome proliferator-activated receptor gamma coactivator 1-A (PPARGC1A) in wild-type vectors, suggesting that they are target genes of miR-148a. The expression of miR-148a was highly negatively correlated with PPARGC1A (r = -0.789, p < 0.001) in ovine mammary gland tissue, while it had a moderate negative correlation with DNMT1 (r = -0.515, p = 0.029). This is the first study to reveal the molecular mechanisms of miR-148a underlying the viability, proliferation, and milk fat synthesis of OMECs in sheep.
Assuntos
Proliferação de Células , Sobrevivência Celular , DNA (Citosina-5-)-Metiltransferase 1 , Células Epiteliais , Glândulas Mamárias Animais , MicroRNAs , Leite , Animais , MicroRNAs/genética , MicroRNAs/metabolismo , Células Epiteliais/metabolismo , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/citologia , Feminino , Ovinos , Leite/metabolismo , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , DNA (Citosina-5-)-Metiltransferase 1/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Lactação/genética , Lactação/metabolismo , Regulação da Expressão GênicaRESUMO
BACKGROUND: Asthma is one of the most common chronic diseases among children and adults and can lead to a high health and socioeconomic burden. Allergic rhinitis (AR) often precedes the development of asthma. This study aims to clarify the risk factors for cocurrent asthma in patients with AR in eastern China. METHODS: A cross-sectional study of 3739 patients with AR was performed in eastern China. Patients meeting the criteria for AR were evaluated using a skin-prick test (SPT) of 16 common aeroallergens. A logistic regression analysis was used to assess the risk factors of asthma in patients with AR. RESULTS: The prevalence of asthma in patients with AR was 14.23%. The patients sensitive to dust mites (D. farinae and D. pteronyssinus) had the highest prevalence (76.84% and 73.68%). A significant difference was found in sensitization to four types of allergens (D. farinae, D. pteronyssinus, dog dander, Alternaria alternata) in patients with AR with and without asthma. The strongest risk factor for asthma in patients with AR was an allergy to Aspergillus fumigatus (adjusted OR, 2.42; 95% CI, 1.50-3.90), followed by allergy to D. pteronyssinus (adjusted OR, 2.06; 1.30-3.27), and allergy to dog dander (adjusted OR, 1.92; 1.24-2.97). Various risk factors that are independently associated with asthma in patients with AR were found in different age groups. CONCLUSIONS: We observed a difference in risk factors in patients with AR with and without asthma. Clarifying the risk factors for asthma in patients with AR is important and may be beneficial to the optimal interventions of asthma.
Assuntos
Asma , Rinite Alérgica , Alérgenos/efeitos adversos , Animais , Asma/epidemiologia , Asma/etiologia , China/epidemiologia , Estudos Transversais , Dermatophagoides farinae , Cães , Humanos , Prevalência , Pyroglyphidae , Hipersensibilidade Respiratória/diagnóstico , Hipersensibilidade Respiratória/epidemiologia , Rinite Alérgica/complicações , Rinite Alérgica/epidemiologia , Fatores de Risco , Testes CutâneosRESUMO
MicroRNAs (miRNAs) are small non-coding RNAs that are involved in mammary gland development and lactation in livestock. Little is known about the roles of miRNAs in ovine mammary gland development, hence in this study the expression profiles of miRNAs of the mammary gland tissues of ewes at peak-lactation and during the non-lactating period were investigated using RNA sequencing. A total of 147 mature miRNAs were expressed in the two periods. Compared with peak-lactation, eight miRNAs in the non-lactating ewe mammary gland were significantly up-regulated, whereas fifteen miRNAs were down-regulated. A KEGG analysis revealed that the target genes of the up-regulated miRNAs were significantly enriched in lysosome, Wnt and MAPK signaling pathways, while the target genes of down-regulated miRNAs were significantly enriched in the PI3K-Akt signaling pathway, protein processing in endoplasmic reticulum and axon guidance. These results suggest that further study of the differentially expressed miRNAs could provide a better understanding of the molecular mechanisms of mammary development and lactation in sheep.
Assuntos
Lactação/genética , MicroRNAs/genética , Ovinos/genética , Animais , Feminino , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/fisiologia , Redes e Vias Metabólicas , MicroRNAs/metabolismo , Ovinos/fisiologiaRESUMO
Circular RNAs are a class of noncoding RNA with a widespread occurrence in eukaryote tissues, and with some having been demonstrated to have clear biological function. In sheep, little is known about the role of circular RNAs in mammary gland tissue, and therefore an RNA sequencing approach was used to compare mammary gland tissue expression of circular RNAs in 9 Small Tail Han sheep at peak lactation, and subsequently when they were not lactating. These 9 sheep had their RNA pooled for analysis into 3 libraries from peak lactation and 3 from the nonlactating period. A total of 3,278 and 1,756 circular RNAs were identified in the peak lactation and nonlactating mammary gland tissues, respectively, and the expression and identity of 9 of them was confirmed using reverse transcriptase-polymerase chain reaction analysis and DNA sequencing. The type, chromosomal location and length of the circular RNAs identified were ascertained. Forty upregulated and one downregulated circular RNAs were characterized in the mammary gland tissue at peak lactation compared with the nonlactating mammary gland tissue. Gene ontology enrichment analysis revealed that the parental genes of these differentially expressed circular RNAs were related to molecular function, binding, protein binding, ATP binding, and ion binding. Five differentially expression circular RNAs were selected for further analysis to predict their target microRNAs, and some microRNAs reportedly associated with the development of the mammary gland were found in the constructed circular RNA-microRNA network. This study reveals the expression profiles and characterization of circular RNAs at 2 key stages of mammary gland activity, thereby providing an improved understanding of the roles of circular RNAs in the mammary gland of sheep.
Assuntos
Lactação/genética , Glândulas Mamárias Animais/metabolismo , RNA Circular/análise , Ovinos/genética , Animais , Feminino , Regulação da Expressão Gênica , Lactação/metabolismo , MicroRNAs/genética , RNA Circular/química , Análise de Sequência de RNA/veterináriaRESUMO
Monoclonal antibodies (mAbs) represent an important platform for the development of biotherapeutic products. Most mAbs are produced in mammalian cells, but several mAbs are made in Escherichia coli, including therapeutic fragments. The NISTmAb is a well-characterized reference material made widely available to facilitate the development of both originator biologics and biosimilars. Here, when expressing NISTmAb from codon-optimized constructs in E. coli (eNISTmAb), a truncated variant of its heavy chain was observed. N-terminal protein sequencing and mutagenesis analyses indicated that the truncation resulted from an internal translation initiation from a GTG codon (encoding Val) within eNISTmAb. Using computational and biochemical approaches, we demonstrate that this translation initiates from a weak Shine-Dalgarno sequence and is facilitated by a putative ribosomal protein S1-binding site. We also observed similar internal initiation in the mAb adalimumab (the amino acid sequence of the drug Humira) when expressed in E. coli Of note, these internal initiation regions were likely an unintended result of the codon optimization for E. coli expression, and the amino acid pattern from which it is derived was identified as a Pro-Ser-X-X-X-Val motif. We discuss the implications of our findings for E. coli protein expression and codon optimization and outline possible strategies for reducing the likelihood of internal translation initiation and truncated product formation.
Assuntos
Adalimumab , Escherichia coli , Cadeias Pesadas de Imunoglobulinas , Iniciação Traducional da Cadeia Peptídica , Adalimumab/biossíntese , Adalimumab/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Cadeias Pesadas de Imunoglobulinas/biossíntese , Cadeias Pesadas de Imunoglobulinas/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genéticaRESUMO
Microbial production of antibodies offers the promise of cheap, fast, and efficient production of antibodies at an industrial scale. Limiting this capacity in prokaryotes is the absence of the post-translational machinery, present in dedicated antibody producing eukaryotic cell lines, such as B cells. There has been few and limited success in producing full-length, correctly folded, and assembled IgG in the cytoplasm of prokaryotic cell lines. One such success was achieved by utilizing the genetically engineered Escherichia coli strain SHuffle with an oxidative cytoplasm. Due to the genetic disruption of reductive pathways, SHuffle cells are under constant oxidative stress, including increased levels of hydrogen peroxide (H2O2). The oxidizing capacity of H2O2 was linked to improved disulfide bond formation, by expressing a fusion of two endoplasmic reticulum-resident proteins, the thiol peroxidase GPx7 and the protein disulfide isomerase, PDI. In concert, these proteins mediate disulfide transfer from H2O2 to target proteins via PDI-Gpx7 fusions. The potential of this new strain was tested with Humira, a blockbuster antibody usually produced in eukaryotic cells. Expression results demonstrate that the new engineered SHuffle strain (SHuffle2) could produce Humira IgG four-fold better than the parental strain, both in shake-flask and in high-density fermentation. These preliminary studies guide the field in genetically engineering eukaryotic redox pathways in prokaryotes for the production of complex macromolecules. KEY POINTS: ⢠A eukaryotic redox pathway was engineered into the E. coli strain SHuffle in order to improve the yield of the blockbuster antibody Humira. ⢠The best peroxidase-PDI fusion was selected using bioinformatics and in vivo studies. ⢠Improved yields of Humira were demonstrated at shake-flask and high-density fermenters.
Assuntos
Proteínas de Escherichia coli , Escherichia coli , Adalimumab , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Glutationa Peroxidase , Humanos , Peróxido de Hidrogênio , Peroxidases , Isomerases de Dissulfetos de Proteínas/genéticaRESUMO
BACKGROUND: Although tonsillectomies carry a low-risk for adverse events, postoperative hemorrhage has been reported as the most common complication. AIM: To compare the rates of postoperative secondary hemorrhage for tonsillectomy with or without double-layer suture. MATERIAL AND METHODS: This is a retrospective study of 5087 patients who underwent coblation tonsillectomy with or without suture from 2006 to 2016. All cases had been followed up 3 weeks and severe secondary hemorrhage cases requiring operation were analyzed. RESULTS: The severe secondary hemorrhage rate was statistically higher in group without suture (1.96%) as compared with the group with suture (1.08%). The surgery time (36.55 ± 7.45) was longer in patients with suture as compared to patients without suture (31.50 ± 6.23). In the age between 18 and 49 years group, the higher secondary hemorrhage rate (2.44%) was found in patients without suture. The rate of postoperative hemorrhage (0.96%) was significantly higher in patients without suture as compared with patients with suture (0.36%) on postoperative 5th day. CONCLUSIONS: The risk of severe secondary hemorrhage is reduced in coblation tonsillectomy with suture. The rate of secondary hemorrhage is lower in patients with suture in 18 to 49 years old group and on the 5th day after surgery.
Assuntos
Hemorragia Pós-Operatória/etiologia , Hemorragia Pós-Operatória/prevenção & controle , Técnicas de Sutura , Tonsilectomia/efeitos adversos , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Hemorragia Pós-Operatória/epidemiologia , Estudos Retrospectivos , Tonsilectomia/métodos , Resultado do Tratamento , Adulto JovemRESUMO
OBJECTIVE: To investigate the effect of down-regulation of SND1 expression on senescence of human diploid fibroblasts. METHODS: Western blot and immunohistochemistry were used to detect the expression of SND1 in young or senescent 2BS cells and aged tissues. Immunofluorescence was conducted to detect the localization of SND1 in young 2BS cells. CCK8 and EDU were performed to detect the proliferation of 2BS. Colony formation analysis was used to evaluate the capacity of colony formation of 2BS. Expression chip and RT-qPCR analysis were performed to detect the change of SASP expression level. ß-galactosidase staining was employed to indicate the senescent 2BS cells. RESULTS: The expression of SND1 in the senescent 2BS cells was significantly down-regulated compared with in the younger 2BS cells, and in human colon adenomas, its expression was also significantly down-regulated compared with in non-lesion colon tissues. In young 2BS, knockdown of SND1 inhibited the proliferation and colony formation of 2BS, and led to stronger senescence-associated beta-galactosidase staining (SA-ß-gal). Expression chip and RT-qPCR analysis indicated that knockdown of SND1 up-regulated the expression of senescence-associated secretory phenotype components (SASP). CONCLUSIONS: Our data indicated that down-regulation of SND1 regulated human diploid cell senescence by up-regulating the expression of SASP components.
Assuntos
Senescência Celular , Diploide , Endonucleases , Fibroblastos , Regulação para Baixo , Fibroblastos/metabolismo , Humanos , Proteínas Nucleares/genéticaRESUMO
Vibralactone is isolated from the basidiomycete fungus Boreostereum vibrans as one of the strongest lipase inhibitors. Its unusual ß-lactone-fused bicycle is derived from an aryl ring moiety by an oxidative ring-expansion prior to an intramolecular cyclization. Herein, we report the discovery of the cyclase VibC which belongs to the α/ß-hydrolase superfamily and is involved in the vibralactone biosynthesis. Biochemical and crystal studies suggest that VibC may catalyze an aldol or an electrocyclic reaction initiated by the Ser-His-Asp catalytic triad. For the aldol and pericyclic chemistry in living cells, VibC is a unique hydrolase performing the carbocycle formation of an oxepinone to a fused bicyclic ß-lactone. This presents a naturally occurring, new enzymatic reaction in both aldol and hydrolase (bio)chemistry that will guide future exploitation of these enzymes in synthetic biology for chemical-diversity expansion of natural products.
Assuntos
Basidiomycota/química , Produtos Biológicos/metabolismo , Hidrolases/metabolismo , Lactonas/metabolismo , Biocatálise , Produtos Biológicos/química , Cristalografia por Raios X , Ciclização , Hidrolases/química , Lactonas/química , Lactonas/isolamento & purificação , Modelos Moleculares , Estrutura MolecularRESUMO
Escherichia coli DsbB is a transmembrane enzyme that catalyzes the reoxidation of the periplasmic oxidase DsbA by ubiquinone. Here, we sought to convert membrane-bound DsbB into a water-soluble biocatalyst by leveraging a previously described method for in vivo solubilization of integral membrane proteins (IMPs). When solubilized DsbB variants were coexpressed with an export-defective copy of DsbA in the cytoplasm of wild-type E. coli cells, artificial oxidation pathways were created that efficiently catalyzed de novo disulfide-bond formation in a range of substrate proteins, in a manner dependent on both DsbA and quinone. Hence, DsbB solubilization was achieved with preservation of both catalytic activity and substrate specificity. Moreover, given the generality of the solubilization technique, the results presented here should pave the way to unlocking the biocatalytic potential of other membrane-bound enzymes whose utility has been limited by poor stability of IMPs outside of their native lipid-bilayer context.
Assuntos
Proteínas de Bactérias/química , Dissulfetos/química , Proteínas de Membrana/química , Água/química , Proteínas de Bactérias/genética , Catálise , Variação Genética , Proteínas de Membrana/genética , Modelos Biológicos , Engenharia de Proteínas , Dobramento de Proteína , SolubilidadeRESUMO
A transmission-blocking vaccine targeting the sexual stages of Plasmodium species could play a key role in eradicating malaria. Multiple studies have identified the P. falciparum proteins Pfs25 and Pfs48/45 as prime targets for transmission-blocking vaccines. Although significant advances have been made in recombinant expression of these antigens, they remain difficult to produce at large scale and lack strong immunogenicity as subunit antigens. We linked a self-assembling protein, granule lattice protein 1 (Grl1p), from the ciliated protozoan, Tetrahymena thermophila, to regions of the ectodomains of either Pfs25 or Pfs48/45. We found that resulting protein chimera could be produced in E. coli as nanoparticles that could be readily purified in soluble form. When produced in the E. coli SHuffle strain, fusion to Grl1p dramatically increased solubility of target antigens while at the same time directing the formation of particles with diameters centering on 38 and 25â¯nm depending on the antigen. In a number of instances, co-expression with chaperone proteins and induction at a lower temperature further increased expression and solubility. Based on Western blotting and ELISA analysis, Pfs25 and Pfs48/45 retained their transmission-blocking epitopes within E. coli-derived particles, and the particles themselves elicited strong antibody responses in rabbits when given with an aluminum-based adjuvant. Antibodies against Pfs25-containing nanoparticles blocked parasite transmission in standard membrane-feeding assays. In conclusion, fusion to Grl1p can act as a solubility enhancer for proteins with limited solubility while retaining correct folding, which may be useful for applications such as the production of vaccines and other biologics.
Assuntos
Anticorpos Antiprotozoários/biossíntese , Proteínas de Ligação ao Cálcio/genética , Vacinas Antimaláricas/genética , Malária Falciparum/prevenção & controle , Glicoproteínas de Membrana/genética , Plasmodium falciparum/química , Proteínas de Protozoários/genética , Tetrahymena thermophila/química , Animais , Antígenos de Protozoários/administração & dosagem , Antígenos de Protozoários/química , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Bioensaio , Proteínas de Ligação ao Cálcio/administração & dosagem , Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/imunologia , Clonagem Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Imunogenicidade da Vacina , Vacinas Antimaláricas/administração & dosagem , Malária Falciparum/imunologia , Malária Falciparum/parasitologia , Glicoproteínas de Membrana/administração & dosagem , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/imunologia , Mosquitos Vetores/parasitologia , Nanopartículas , Plasmodium falciparum/imunologia , Dobramento de Proteína , Proteínas de Protozoários/administração & dosagem , Proteínas de Protozoários/química , Proteínas de Protozoários/imunologia , Coelhos , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Solubilidade , Tetrahymena thermophila/imunologiaRESUMO
A phytochemical investigation to obtain chemical components with potential anti-inflammatory activity from E. hylonoma led to the isolation of nine new ent-isopimarane diterpenoids (1 and 3-10), a new ent-rosane diterpenoid (11), along with eight known ones (2 and 12-18) using various chromatographic techniques. Compounds 3, 4, 5, and 10 were rare examples of the epoxy-ent-isopimarane. The structures of these new compounds were confirmed by extensive spectroscopic data, crystal X-ray diffraction analysis, and electronic circular dichroism. And the isolates were evaluated for their inhibitory effects on nitric oxide production induced by lipopolysaccharide in RAW 264.7 cells. The results showed that compounds 2 and 12 exhibited noteworthy inhibitory effects against NO production with IC50 values of 7.12 and 12.73⯵M, respectively, which were better than positive control (IC50â¯=â¯41.41⯵M). The possible mechanism that compounds 2 and 12 could inhibit NO production was investigated by the Western blotting experiments.
Assuntos
Diterpenos/química , Euphorbia/química , Animais , Anti-Inflamatórios , Macrófagos/efeitos dos fármacos , Camundongos , Modelos Moleculares , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Células RAW 264.7 , Relação Estrutura-AtividadeRESUMO
Disulfide bonds influence the stability and activity of many proteins. In Escherichia coli, the DsbA and DsbB enzymes promote disulfide bond formation. Other bacteria, including the Actinobacteria, use instead of DsbB the enzyme vitamin K epoxide reductase (VKOR), whose gene is found either fused to or in the same operon as a dsbA-like gene. Mycobacterium tuberculosis and other Gram-positive actinobacteria secrete many proteins with even numbers of cysteines to the cell envelope. These organisms have predicted oxidoreductases and VKOR orthologs. These findings indicate that such bacteria likely form disulfide bonds in the cell envelope. The M. tuberculosisvkor gene complements an E. colidsbB deletion strain, restoring the oxidation of E. coli DsbA. While we have suggested that the dsbA gene linked to the vkor gene may express VKOR's partner in mycobacteria, others have suggested that two other extracytoplasmic oxidoreductases (DsbE or DsbF) may be catalysts of protein disulfide bond formation. However, there is no direct evidence for interactions of VKOR with either DsbA, DsbE, or DsbF. To identify the actual substrate of VKOR, we identified two additional predicted extracytoplasmic DsbA-like proteins using bioinformatics analysis of the M. tuberculosis genome. Using the five potential DsbAs, we attempted to reconstitute disulfide bond pathways in E. coli and in Mycobacterium smegmatis, a close relative of M. tuberculosis Our results show that only M. tuberculosis DsbA is oxidized by VKOR. Comparison of the properties of dsbA- and vkor-null mutants in M. smegmatis shows parallels to the properties of dsb mutations in E. coliIMPORTANCE Disulfide bond formation has a great impact on bacterial pathogenicity. Thus, disulfide-bond-forming proteins represent new targets for the development of antibacterials, since the inhibition of disulfide bond formation would result in the simultaneous loss of the activity of several classes of virulence factors. Here, we identified five candidate proteins encoded by the M. tuberculosis genome as possible substrates of the M. tuberculosis VKOR protein involved in disulfide bond formation. We then reconstituted the mycobacterial disulfide bond formation pathway in E. coli and showed that of the five candidates, only M. tuberculosis DsbA is efficiently oxidized by VKOR in E. coli We also present evidence for the involvement of VKOR in DsbA oxidation in M. smegmatis.
Assuntos
Proteínas de Bactérias/genética , Dissulfetos/metabolismo , Mycobacterium tuberculosis/genética , Tiorredoxinas/metabolismo , Vitamina K Epóxido Redutases/genética , Proteínas de Bactérias/metabolismo , Cristalografia por Raios X , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Modelos Moleculares , Mycobacterium tuberculosis/enzimologia , Mycobacterium tuberculosis/patogenicidade , Oxirredução , Oxirredutases , Isomerases de Dissulfetos de Proteínas/metabolismo , Vitamina K Epóxido Redutases/metabolismoRESUMO
Ten new triterpenoids, ailanaltiolides A-J (1-10), and three known analogues (11-13) were isolated from the roots of Ailanthus altissima. Compounds 1-7 are apotirucallane-type, compounds 8 and 9 are tirucallane-type, and compound 10 is a trinordammarane-type triterpenoid. This is the first study indicating the genus Ailanthus as a potential source for apotirucallane derivatives, which contain an α,ß-unsaturated-ε-lactone A-ring and diversely modified C-17 side chains. Spectroscopic data interpretation, electronic circular dichroism analysis, and X-ray crystallographic data defined the structures and absolute configurations of these triterpenoids. Compounds 2, 7, and 8 showed cytotoxicity against four tumor cell lines (HeLa, 786-O, HepG2, and A549). In particular, compound 2 exhibited the highest activity against 786-O cells with an IC50 value of 8.2 µM in vitro.
Assuntos
Ailanthus/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Raízes de Plantas/química , Triterpenos/química , Triterpenos/farmacologia , Linhagem Celular Tumoral , Dicroísmo Circular , Humanos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Difração de Raios XRESUMO
In bacteria, disulfide bonds confer stability on many proteins exported to the cell envelope or beyond. These proteins include numerous bacterial virulence factors, and thus bacterial enzymes that promote disulfide bond formation represent targets for compounds inhibiting bacterial virulence. Here, we describe a new target- and cell-based screening methodology for identifying compounds that inhibit the disulfide bond-forming enzymes Escherichia coli DsbB (EcDsbB) or Mycobacterium tuberculosis VKOR (MtbVKOR), which can replace EcDsbB, although the two are not homologs. Initial screening of 51,487 compounds yielded six specifically inhibiting EcDsbB. These compounds share a structural motif and do not inhibit MtbVKOR. A medicinal chemistry approach led us to select related compounds, some of which are much more effective DsbB inhibitors than those found in the screen. These compounds inhibit purified DsbB and prevent anaerobic growth of E. coli. Furthermore, these compounds inhibit all but one of the DsbBs of nine other Gram-negative pathogenic bacteria tested.
Assuntos
Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/química , Escherichia coli/metabolismo , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/química , Mycobacterium tuberculosis/metabolismo , Ágar/química , Antibacterianos/química , Domínio Catalítico , Química Farmacêutica/métodos , Técnicas de Química Combinatória , Dissulfetos , Relação Dose-Resposta a Droga , Desenho de Fármacos , Transporte de Elétrons , Proteínas de Escherichia coli/antagonistas & inibidores , Proteínas de Escherichia coli/química , Espectrometria de Massas , Testes de Sensibilidade Microbiana , Mycobacterium smegmatis/metabolismo , Conformação Proteica , Isomerases de Dissulfetos de Proteínas/antagonistas & inibidores , Isomerases de Dissulfetos de Proteínas/química , Pseudomonas aeruginosa/metabolismoRESUMO
Objective To observe effects of Kangxianling Recipe ( KXLR) on p38MAPK/NF- κBp65 mediated inflammatory factors in chronic renal failure ( CRF) model mice. Methods Totally 56 C57BL/6J male mice (18 -22 g) were recruited in this experiment. Ten were randomly selected as a sham-operation group. The rest 46 mice were used for preparing CRF model by 5/6 nephrectomization. To- tally 33 successfully modeled mice were divided into the model group, the rapamycin (RAP) group, and the KXLR group according to serum creatinine (SCr) level, 11 in each group. Mice in the RAP group were administered with rapamycin (0.13 mg/100 g per day, 0. 5 mL each time) by gastrogavage. Mice in the KXLR group were administered with KXLR (2 g/100 g per day, 0. 5 mL each time) by gastrogavage. Equal volume of distilled water was administered to mice in the model group and the sham-operation group. Mice were sacrificed after 8 weeks of consecutive medication. The expression of neutrophils was ob- served using immunohistochemical assay. Expression levels of p38MAPK/NF-κB p65 protein and TNF-α/ IL-6 mRNA were detected by Western blot and Real-time PCR. Results Compared with the sham-opera- tion group, the number of positive neutrophils increased, expression levels of p38MAPK/NF-κB p65 protein and TNF-α/IL-6 mRNA were enhanced significantly in the model group (P <0. 05, P <0. 01). Com- pared with the model group, the number of neutrophils was reduced, expression levels of p38MAPK/NF- κB p65 protein and TNF-α/IL-6 mRNA were decreased significantly in the KXLR group and the RAP group (P <0. 05, P <0. 01). RAP showed better effect in decreasing p38MAPK protein expression than KXLR (P <0. 05). There was no statistical difference in the rest indices between the KXLR group and the RAP group (P >0. 05). Conclusions KXLR participated the regulation of p38MAPK/NF-κB p65 mediated in- flammation factors. It had certain improvement in renal fibrosis induced renal failure.
Assuntos
Medicamentos de Ervas Chinesas , Nefropatias , Proteínas Quinases p38 Ativadas por Mitógeno , Animais , Medicamentos de Ervas Chinesas/farmacologia , Nefropatias/tratamento farmacológico , Nefropatias/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/efeitos dos fármacos , NF-kappa B/metabolismo , Fator de Necrose Tumoral alfa , Proteínas Quinases p38 Ativadas por Mitógeno/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
UNLABELLED: The use of fluorescent and luminescent proteins in visualizing proteins has become a powerful tool in understanding molecular and cellular processes within living organisms. This success has resulted in an ever-increasing demand for new and more versatile protein-labeling tools that permit light-based detection of proteins within living cells. In this report, we present data supporting the use of the self-labeling HaloTag protein as a light-emitting reporter for protein fusions within the model prokaryote Escherichia coli. We show that functional protein fusions of the HaloTag can be detected both in vivo and in vitro when expressed within the cytoplasmic or periplasmic compartments of E. coli. The capacity to visually detect proteins localized in various prokaryotic compartments expands today's molecular biologist toolbox and paves the path to new applications. IMPORTANCE: Visualizing proteins microscopically within living cells is important for understanding both the biology of cells and the role of proteins within living cells. Currently, the most common tool is green fluorescent protein (GFP). However, fluorescent proteins such as GFP have many limitations; therefore, the field of molecular biology is always in need of new tools to visualize proteins. In this paper, we demonstrate, for the first time, the use of HaloTag to visualize proteins in two different compartments within the model prokaryote Escherichia coli. The use of HaloTag as an additional tool to visualize proteins within prokaryotes increases our capacity to ask about and understand the role of proteins within living cells.
Assuntos
Proteínas de Bactérias/metabolismo , Citoplasma/metabolismo , Escherichia coli/metabolismo , Periplasma/metabolismo , Rhodococcus/enzimologia , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica/fisiologia , Modelos Moleculares , Mutação , Periplasma/química , Plasmídeos , Conformação Proteica , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/química , Rhodococcus/metabolismo , Coloração e RotulagemRESUMO
Objective To evaluate the clinical effectiveness of JianpiQinghua decoction in treating stage 3 chronic kidney disease (CKD3) with syndrome type of dampness-heat due to spleen deficiency. Methods A multicenter, randomized, controlled, prospective, double-blind, and double-simulation study was undertaken. A total of 270 CKD3 patients with syndrome type of dampness-heat due to spleen deficiency from the outpatient departments of six general hospitals were randomly divided into telmisartan+analog traditional Chinese medicine (TA) group, traditional Chinese medicine+analog telmisartan (TCMA) group, and telmisartan+traditional Chinese medicine (TTCM) group, in which the corresponding treatment was applied in addition to basic treatment. Six months later, changes in the traditional Chinese medicine (TCM) clinical symptom scores and renal functions before and after treatment were compared among these three groups. Results Of these 270 CKD3 patients who had been enrolled in this study, 30 cases lost to follow-up. The baseline data were comparable among these three groups. After treatment, the TCM clinical symptom scores of both syndrome of spleen-qi deficiency and dampness-heat in TA group were significantly higher than those in TCMA group and TTCM group (P<0.001). With the treatment time prolonged, the TCM clinical symptom scores showed similar descending trends in TCMA group and TTCM group but were different from that in TA group. After treatment, abnormal creatinine rate decreased (P=0.003), and these three treatments and their interactions with each visit had no effect on serum urea nitrogen value (P=0.270, P=0.520); with prolonged treatment, the estimated glomerular filtration rates in three groups tended to be relatively stable after the first rise. The liver function and abnormal serum potassium rate were not statistically significant before and after treatment (P>0.05). Conclusions JianpiQinghua decoction can improve clinical symptoms of TCM in CKD3 patients with syndrome type of dampness-heat due to spleen deficiency and thus improve the quality of life and prognosis. The clinical efficacy of JianpiQinghua decoction alone or combined with telmisartan is superior to telmisartan monotherapy.