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1.
Biotechnol Appl Biochem ; 70(2): 688-696, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35932185

RESUMO

The bacterium Caulobacter crescentus secretes an adhesive polysaccharide called holdfast, which is the known strongest underwater adhesive in nature. The deacetylase encoded by hfs (holdfast synthesis) H gene is a key factor affecting the adhesion of holdfast. Its structure and function are not yet clear, and whether other polysaccharide deacetylases exist in C. crescentus is still unknown. The screening of both HfsH and its structural analogue as well as their purification from the artificial expression products of Escherichia coli is the first step to clarify these questions. Here, we determined the conserved domains of HfsH via sequence alignment among carbohydrate esterase family 4 enzymes and screened out its structural analogue (CC_2574) in C. crescentus. The recombinant HfsH and CC_2574 were effectively expressed in E. coli. Both of them were purified by chromatography from their corresponding productions in E. coli and were then functionally analyzed. The results indicated that a high deacetylase activity (61.8 U/mg) was observed in recombinant HfsH but not in CC_2574, which suggesting that HfsH might be the irreplaceable gene mediating adhesion of holdfast in C. crescentus. Moreover, the divalent metal ions Zn2+ , Mg2+ , and Mn2+ could promote the activity of recombinant HfsH at the concentration from 0.05 to 1 mM, but inhibit its activity when the concentration exceeds 1 mM. In sum, our study first realized the artificial production of polysaccharide deacetylase HfsH and its structural analogue, and further explored their functions, both of which laid the foundation for the development of new adhesive materials.


Assuntos
Aderência Bacteriana , Caulobacter crescentus , Aderência Bacteriana/genética , Caulobacter crescentus/genética , Caulobacter crescentus/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Hormônio Foliculoestimulante Humano/metabolismo , Polissacarídeos/metabolismo , Proteínas de Bactérias/genética
2.
Mol Genet Genomics ; 294(2): 277-286, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30374564

RESUMO

Gene circuits are constructed to run complex logical operations for the precise regulation of biological metabolic processes. At present, the implementation of most genetic circuits is based on the regulatory mechanism of various circuit components, but we hope to realize complex logic gates through biological metabolic pathways of organisms. In this study, we matched the regulatory elements of different functional mechanisms to build a Boolean logic gate model by means of a dual-vector circuit. In Escherichia coli, we made 12 circuit logic gate modules and validated the functions of four of the logic gates, including "AND", "NAND", "OR" and "NOR" by the expression and analysis of a reporter gene. The inputs were converted into outputs by an intermediate product of the host metabolism. The results indicated that these logic gate circuits had the expected efficacy and regulatory characteristics. Our study provides new ideas for designing genetic circuits and precisely controlling metabolic pathways.


Assuntos
Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica/genética , Redes Reguladoras de Genes/genética , Redes e Vias Metabólicas/genética , Interações Hospedeiro-Patógeno/genética
3.
J Neuroinflammation ; 15(1): 16, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29334965

RESUMO

BACKGROUND: Current options to treat clinical relapse in inflammatory central nervous system (CNS) conditions such as cerebral ischemia-reperfusion injury are limited, and agents that are more effective are required. Disruption of the blood-brain barrier is an early feature of lesion formation that correlates with clinical exacerbation and facilitates the entry of inflammatory medium and inflammatory cells. Interleukin-1 receptor antagonist (IL-1RA) is a naturally occurring anti-inflammatory antagonist of the interleukin-1 (IL-1) family. The broad-spectrum anti-inflammatory effects of IL-1RA have been investigated against various forms of neuroinflammation. However, the effect of IL-1RA on blood-brain barrier disruption following ischemia-reperfusion has not been reported. METHODS: In this study, we investigated the effects of IL-1RA and a novel protein (IL-1RA-PEP) that was fused to IL-1RA with a cell penetrating peptide, on blood-brain barrier integrity, in male rats subjected to transient middle cerebral artery occlusion. RESULTS: After intravenous administration, IL-1RA-PEP (50 mg/kg) penetrated cerebral tissues more effectively than IL-1RA. Moreover, it preserved blood-brain barrier integrity, attenuated changes in expression and localization of tight junction proteins and matrix metalloproteinases, and enhanced angiogenesis in ischemic brain tissue. Further study suggested that the effects of IL-1RA-PEP on preserving blood-brain barrier integrity might be closely correlated with the p65/NF-κB pathway, as evidenced by the effects of the inhibitor JSH-23. CONCLUSIONS: Collectively, our results demonstrated that IL-1RA-PEP could effectively penetrate the brain of rats with middle cerebral artery occlusion and ameliorate blood-brain barrier disruption. This finding might represent its novel therapeutic potential in the treatment of the cerebral ischemia-reperfusion injury.


Assuntos
Barreira Hematoencefálica/metabolismo , Isquemia Encefálica/metabolismo , Cisteamina/análogos & derivados , Proteína Antagonista do Receptor de Interleucina 1/metabolismo , Peptídeos/metabolismo , Traumatismo por Reperfusão/metabolismo , Administração Intravenosa , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Isquemia Encefálica/tratamento farmacológico , Cisteamina/administração & dosagem , Cisteamina/metabolismo , Proteína Antagonista do Receptor de Interleucina 1/administração & dosagem , Masculino , Peptídeos/administração & dosagem , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/tratamento farmacológico
4.
BMC Infect Dis ; 17(1): 164, 2017 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-28222680

RESUMO

BACKGROUND: Current diagnostic methods for Schistosoma japonicum infection are insensitive for low-density infections. Therefore, a new diagnostic assay based on recombinase polymerase amplification (RPA) technology was established and assessed for field applification. METHODS: The S.japonicum RPA assay was developed to target highly repetitive retrotransposon SjR2 gene of S japonicum, and its sensitivity and specificity were assessed by serial dilution of S. japonicum genomic DNA and other related worm genomic DNA respectively. The RPA diagnostic validity was first evaluated in 60 fecal samples from healthy people and patients, and then compared with other diagnostic tests in 200 high-risk individuals living in endemic areas. RESULTS: The real time RPA assay could detect 0.9 fg S. japonicum DNA within 15 min and distinguish S. japonicum from other worms. The validity analysis of RPA for the detection of S. japonicum in stool samples from 30 S. japonicum-infected patients and 30 healthy persons indicated 100% sensitivity and specificity. When testing 200 fecal or serum samples from a high-risk population, the percentage sensitivity of RPA was 100%, whereas that of indirect hemagglutination assay (IHA) and enzyme-linked immunosorbent assay (ELISA) were 80.3% and 85.2% respectively. In addition, the RPA presented better consistency with the stool-based tests than IHA and ELISA. Overall, the RPA was superior to other detection methods with respect to detection time, sensitivity, and convenience. CONCLUSIONS: This is the first time we applied the RPA technology to the field evaluation of S. japonicum infection. And the results suggest that RPA-based assays can be used as a promising point-of-care test for the diagnosis of schistosomiasis.


Assuntos
Sistemas Automatizados de Assistência Junto ao Leito , Reação em Cadeia da Polimerase/métodos , Schistosoma japonicum/isolamento & purificação , Esquistossomose Japônica/diagnóstico , Adolescente , Adulto , Idoso , Animais , Estudos de Casos e Controles , China/epidemiologia , DNA de Helmintos/análise , Ensaio de Imunoadsorção Enzimática , Feminino , Testes de Hemaglutinação , Humanos , Masculino , Pessoa de Meia-Idade , Recombinases , Schistosoma japonicum/genética , Sensibilidade e Especificidade , Adulto Jovem
5.
Int J Mol Sci ; 18(4)2017 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-28422048

RESUMO

SAK-HV is an anti-atherosclerosis recombinant fusion protein developed by our lab. Our study determined that SAK-HV promoted macrophage proliferation, of which the mechanism was explored by both RAW264.7 cells and primary macrophages. Mass spectrometric analysis and co-immunoprecipitation were combined to screen the SAK-HV-interacting proteins in RAW264.7 cells. Confocal microscopy was adopted to detect the localization of SAK-HV in cells. The results indicated that SAK-HV triggered macrophage proliferation via the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinases (ERK) and c-Jun N-terminal kinases (JNK) pathways by its SAK-mutant functional domain. We screened out Uba1 as the SAK-HV-interacting protein in the RAW264.7 cells and discovered their co-localization in the cytoplasm and nucleus. Inhibiting Uba1 significantly decreased the SAK-HV-induced macrophage proliferation. Thus, we postulated an attractive model of ubiquitination, in which the interactions between Uba1 and specific E2 enzymes are blocked by its interaction with SAK-HV. Based on this model, we detected the decreased self-ubiquitination of MEKK1 after SAK-HV treatment and concluded that SAK-HV inhibits the self-ubiquitination of MEKK1 via its SAK-mutant functional domain to activate MAPK/ERK and JNK pathways, promoting macrophage proliferation. This conclusion highly supported our hypothesized model of ubiquitination at the level of Uba1, which may represent a novel paradigm to promote macrophage proliferation by using the E1 enzyme (Uba1) as a switch.


Assuntos
MAP Quinase Quinase Quinase 1/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Camundongos , Mutação , Fosforilação , Domínios e Motivos de Interação entre Proteínas/genética , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Ubiquitinação/efeitos dos fármacos
6.
Int J Mol Sci ; 18(7)2017 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-28714941

RESUMO

Epidemiological and clinical studies have increasingly shown that fine particulate matter (PM2.5) is associated with cardiovascular morbidity and mortality, which share the common feature of PM2.5-induced vascular inflammation; however, the underlying mechanisms of how PM2.5 triggers increased inflammatory response in vascular endothelial cells are not well understood. After treating mouse aortic endothelial cells (MAECs) with different concentrations of PM2.5, we assessed interleukin (IL)-6 and four and a half LIM domains 2 (FHL2) expression in cell supernatant by enzyme-linked immunosorbent assay and Western blot, respectively, as well as activation of nuclear factor (NF)-κB and immune-response signaling pathways. Additionally, changes in pathway activation, IL-6 expression, and autophagy were evaluated under PM2.5 exposure, following FHL2 knockdown with small interfering RNA. Our results indicated that PM2.5 exposure induced FHL2 expression and IL-6 secretion, as well as activation of pathways associated with immune response. Additionally, following FHL2 knockdown, the activation of NF-κB-related pathways and IL-6 secretion was inhibited under PM2.5 exposure, although the Akt- and p38-signaling pathways were not affected. Furthermore, PM2.5 exposure induced autophagy, whereas autophagy inhibition eventually inhibited PM2.5-induced FHL2 expression. These findings suggested a novel link between autophagy induced FHL2 upregulation and IL-6 production in MAECs under PM2.5 exposure.


Assuntos
Aorta/citologia , Interleucina-6/metabolismo , Proteínas com Homeodomínio LIM/metabolismo , Proteínas Musculares/metabolismo , NF-kappa B/metabolismo , Material Particulado/toxicidade , Fatores de Transcrição/metabolismo , Regulação para Cima , Animais , Aorta/efeitos dos fármacos , Aorta/imunologia , Autofagia , Sobrevivência Celular/efeitos dos fármacos , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/imunologia , Técnicas de Silenciamento de Genes , Proteínas com Homeodomínio LIM/genética , Camundongos , Proteínas Musculares/genética , Transdução de Sinais , Fatores de Transcrição/genética , Ativação Transcricional
7.
Epigenetics Chromatin ; 17(1): 26, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39118189

RESUMO

Poly (ADP-ribose) polymerase 1 (PARP1) is a multifunctional nuclear enzyme that catalyzes poly-ADP ribosylation in eukaryotic cells. In addition to maintaining genomic integrity, this nuclear enzyme is also involved in transcriptional regulation. PARP1 can trigger and maintain changes in the chromatin structure and directly recruit transcription factors. PARP1 also prevents DNA methylation. However, most previous reviews on PARP1 have focused on its involvement in maintaining genome integrity, with less focus on its transcriptional regulatory function. This article comprehensively reviews the transcriptional regulatory function of PARP1 and its application in disease treatment, providing new ideas for targeting PARP1 for the treatment of diseases other than cancer.


Assuntos
Poli(ADP-Ribose) Polimerase-1 , Transcrição Gênica , Humanos , Poli(ADP-Ribose) Polimerase-1/metabolismo , Animais , Neoplasias/genética , Neoplasias/metabolismo , Regulação da Expressão Gênica , Metilação de DNA , Cromatina/metabolismo
8.
Int J Biol Macromol ; 275(Pt 2): 133720, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38987000

RESUMO

Tick-borne encephalitis virus (TBEV), a zoonotic pathogen, can cause severe neurological complications and fatal outcomes in humans. Early diagnosis of TBEV infection is crucial for clinical practice. Although serological assays are frequently employed for detection, the lack of antibodies in the early stages of infection and the cross-reactivity of antibodies limit their efficacy. Conventional molecular diagnostic methods such as RT-qPCR can achieve early and accurate identification but require specialized instrumentation and professionals, hindering their application in resource-limited areas. Our study developed a rapid and visual TBEV molecular detection method by combining RT-recombinase-aided amplification, the CRISPR/Cas13a system, and lateral flow dipsticks. The diagnostic sensitivity of this method is 50 CFU/ml, with no cross-reactivity with a variety of viruses. The detection can be carried out within 1 h at a temperature between 37 and 42 °C, and the results can be visually determined without the need for complex instruments and professionals. Subsequently, this assay was used to analyze clinical samples from 15 patients suspected of TBEV infection and 10 healthy volunteers, and its sensitivity and specificity reached 100 %, which was consistent with the results of RT-qPCR. These results indicate that this new method can be a promising point-of-care test for the diagnosis of tick-borne encephalitis.


Assuntos
Sistemas CRISPR-Cas , Vírus da Encefalite Transmitidos por Carrapatos , Recombinases , Vírus da Encefalite Transmitidos por Carrapatos/genética , Humanos , Recombinases/metabolismo , Técnicas de Amplificação de Ácido Nucleico/métodos , Encefalite Transmitida por Carrapatos/diagnóstico , Encefalite Transmitida por Carrapatos/virologia , Encefalite Transmitida por Carrapatos/sangue , Sensibilidade e Especificidade , RNA Viral/genética , Técnicas de Diagnóstico Molecular/métodos
9.
J Asthma ; 50(2): 209-14, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23294145

RESUMO

BACKGROUND: The presence of transient receptor potential vanilloid 2 (TRPV2) in human peripheral blood cells may suggest a role under pathological conditions. The aim of this study was to explore the relationship between the expression profile of TRPV2 gene and childhood asthma in the north of China. The effects of allergens exposure on the expression of TRPV2 gene were also investigated. METHODS: Sixty asthmatics children confirmed by physician diagnosis and 60 healthy children as a control group were recruited. Serum total IgE and specific IgE were measured. Using quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR), TRPV2 was detected in total RNA extracted from peripheral blood lymphocytes. Student's t-test and chi-square test were used to analyze the relationship between TRPV2 transcript and different parameter variables on susceptibility of childhood asthma. Multiple logistic regression was used to analyze the associations between TRPV2 gene and allergens. RESULTS: The expression level of TRPV2 gene was increased 2.6 times in asthmatic children compared with controls (p < .01). The up-regulation of TRPV2 gene and sensitization to one of three the allergens-spring pollen, dust mite, and dog and cat hair-were correlated with childhood asthma. In addition, the hypersensitivity to spring pollen, cockroach, and dust mite and up-regulation of TRPV2 gene expression may be the risk factors for the childhood asthma in Beijing. CONCLUSIONS: The increased expression of TRPV2 gene in peripheral lymphocytes is closely correlated with childhood asthma in the north of China. This study provides a potential new biomarker of childhood asthma and lays the basis for further clarification of the pathogenesis underlying asthma.


Assuntos
Asma/metabolismo , Canais de Cátion TRPV/metabolismo , Alérgenos/imunologia , Asma/sangue , Asma/genética , Asma/imunologia , Biomarcadores/sangue , Estudos de Casos e Controles , Criança , Pré-Escolar , China , Feminino , Regulação da Expressão Gênica , Humanos , Imunoglobulina E/sangue , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Modelos Logísticos , Masculino , RNA/química , RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Canais de Cátion TRPV/sangue , Canais de Cátion TRPV/genética , Canais de Cátion TRPV/imunologia , População Urbana
10.
Microbiol Spectr ; 11(3): e0517022, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37022182

RESUMO

Human adenoviruses (HAdVs) are common viruses that can cause local outbreaks in schools, communities and military camps, posing a huge threat to public health. An ideal POCT device for adenovirus detection in resource-limited settings is critical to control the spread of the virus. In this study, we developed an integrated and electricity-independent sample-to-answer system that can complete nucleic acid extraction, amplification, and detection at room temperature. This system is suitable for field and on-site detection because of its rapidity, sensitivity, lack of contamination, and lack of requirements of high-precision instruments and skilled technicians. It consists of two separate modules, ALP FINA (alkaline lysis with the paper-based filtration isolation of nucleic acid) and SV RPA (sealed and visual recombinase polymerase amplification). The extraction efficiency of ALP FINA can reach 48 to 84%, which is close to that of the conventional centrifuge column. The detection sensitivity of SV RPA is close to 10 copies/µL of AdvB and AdvE without aerosol contamination after repeated operations. When SV RPA was applied to the detection of nasopharyngeal swab samples of 19 patients who were infected with AdvB or AdvE as well as 10 healthy volunteers, its sensitivity and specificity reached 100%, respectively. IMPORTANCE HAdV infections are readily transmittable and, in some instances, highly contagious. Early and rapid diagnosis is essential for disease control. In this work, we developed a portable, disposable, and modularized sample-to-answer detection system for AdvB and AdvE, which rendered the entire test to be completely independent of electricity and other laboratory infrastructure. Thus, this detection system can be applied in resource-limited settings, and it has the potential to be further developed as an early diagnosis method in the field.


Assuntos
Adenovírus Humanos , Ácidos Nucleicos , Humanos , Técnicas de Amplificação de Ácido Nucleico/métodos , Adenoviridae , Sensibilidade e Especificidade , Adenovírus Humanos/genética , Recombinases
11.
Biosci Biotechnol Biochem ; 76(7): 1384-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22785483

RESUMO

The potential of angiogenin (Ang) for clinical use has been highlighted in view of its important roles in inducing angiogenesis, facilitating cell proliferation, and inhibiting cell apoptosis. To produce soluble, correctly folded recombinant protein with a high yield, a DNA fragment encoding human Ang was inserted into eukaryotic expression vector pPIC9 and transformed into Pichia pastoris. The expression of recombinant human Ang (rhAng) accounted for about 70% of total secreted proteins. Purifying the Ang from the culture supernatant yielded 30 mg/L at 90% purity by chromatography with a SP Sepharose FF column. Biological assays indicated that rhAng can induce new blood-vessel formation, promote HeLa cell proliferation, increase Erk1/2 phosphorylation, and upregulate c-myc expression. Preparation of bioactive rhAng might lay the basis for further functional study, and might provide an effective strategy for large-scale production of soluble human Ang.


Assuntos
Membrana Corioalantoide/irrigação sanguínea , Expressão Gênica , Pichia/genética , Proteínas Recombinantes/isolamento & purificação , Ribonuclease Pancreático/isolamento & purificação , Animais , Bioensaio , Proliferação de Células/efeitos dos fármacos , Embrião de Galinha , Membrana Corioalantoide/efeitos dos fármacos , Cromatografia , Vetores Genéticos , Células HeLa , Humanos , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Neovascularização Fisiológica , Fosforilação/efeitos dos fármacos , Fosforilação/genética , Pichia/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/farmacologia , Ribonuclease Pancreático/biossíntese , Ribonuclease Pancreático/farmacologia , Transformação Genética
12.
World J Microbiol Biotechnol ; 28(2): 523-31, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22806847

RESUMO

This study was aimed to rapidly identify and differentiate two main pathogens of the Mycobacterium tuberculosis complex: Mycobacterium tuberculosis subsp. tuberculosis and Mycobacterium bovis by a modified loop-mediated isothermal amplification (LAMP) assay. The reaction results could be evaluated by naked eye with two optimized closed tube detection methods as follows: adding the modified fluorescence dye in advance into the reaction mix so as to observe the color changes or putting a tinfoil in the tube and adding the SYBR Green I dye on it, then making the dye drop into the bottom of the tube by centrifuge after reaction. The results showed that the two groups of primers used jointly in this assay could successfully identify and differentiate Mycobacterium tuberculosis subsp. tuberculosis and Mycobacterium tuberculosis bovis. Sensitivity test displayed that the modified LAMP assay with the closed tube system could determine the minimal template concentration of 1 copy/µl, which was more sensitive than that of routine PCR. The advantages of this LAMP method for detection of the Mycobacterium tuberculosis complex included high specificity, high sensitivity, simplicity, and superiority in avoidance of aerosol contamination. The modified LAMP assay would provide a potential for clinical diagnosis and therapy of tuberculosis in the developing countries and the resource-limited areas.


Assuntos
Mycobacterium bovis/genética , Mycobacterium tuberculosis/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas Bacteriológicas/métodos , DNA Bacteriano/genética , Humanos , Mycobacterium bovis/classificação , Mycobacterium tuberculosis/classificação
13.
China CDC Wkly ; 4(26): 577-581, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35919456

RESUMO

Air pollution is a significant risk factor contributing to the burden of disease in China. Health risk assessment and management are important to reduce the impact of air pollution on public health. To help formulate standardized health risk assessment techniques, a series of studies were conducted from 2006 to 2019. Through systematic review, study of molecular mechanisms, epidemiological investigation, and health effect monitoring, the overall project established a monitoring and evaluation indicator system, a comprehensive information platform, software for automatic data cleaning, and standardized health risk assessment techniques. Technical specifications have been issued by the National Health Commission for promoting health risk assessments across China. This paper introduces the project, the research approach, its main research accomplishments, innovations, and public health significance, and describes directions for further research.

14.
Mol Biol Rep ; 37(8): 3909-13, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20229016

RESUMO

Angiopoietin-2 (Ang2) is a member of the Ang family. Its potential in clinical use has been highlighted for its important roles in angiogenesis during the individual development and the growth of tumors. Ang2 is difficult to be expressed in E. coli for its unique structure. The expressions of Ang2 in insect cells (Sf9) and Chinese hamster ovary (CHO) cell line have been reported, however, the large-scale production of Ang2 for application is still pendent. In this study, the expression of Ang2 in Pichia pastoris expression system was described for the first time. The cDNA encoding Ang2 was cloned from the rat vascular tissue by RT-PCR, and inserted in the eukaryotic expression vector pPIZαA, and then transformed into P. pastoris KM71H cells. The expression of recombinant rat Ang2 (rrAng2) was induced by methanol and accounted for about 75% of the total secreted proteins. The recombinant protein was subsequently purified by HisTrap FF crude with a purity of 90%. Functional analysis of the purified rrAng2 demonstrated a specific activity in promoting the survival of ECV304 cells and binding to the Tie2 receptor. Preparation of bioactive rrAng2 not only lays the basis for further functional study but also provides a new strategy for soluble and large-scale production of human Ang2.


Assuntos
Angiopoietina-2/isolamento & purificação , Angiopoietina-2/metabolismo , Pichia/metabolismo , Animais , Bioensaio , Linhagem Celular , Humanos , Plasmídeos , Ratos , Receptor TIE-2/metabolismo , Proteínas Recombinantes/metabolismo
15.
Mol Biol Rep ; 37(6): 2609-13, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19760099

RESUMO

Interleukin-22 (IL-22) is a member of the IL-10 family. Its potential in clinical use has been highlighted for its important roles in promoting antimicrobial defense and preventing epithelial damages. Previous studies have reported that IL-22 can be expressed using prokaryotic systems and purified from inclusion bodies, however the recovery rate was poor. To produce functional IL-22 with a high yield, human IL-22 was inserted into the eukaryotic expression vector pPICZalphaA and transformed into Pichia pastoris. The expression of recombinant human IL-22 (rhIL-22) was induced by methanol and accounted for about 85% of the total secreted proteins. A simple purification strategy was established to purify the rhIL-22 from the culture supernatant, yielding 100 mg/l at 90% purity by chromatography with a SP Sepharose FF column. Bioactivity analysis showed the purified rhIL-22 demonstrated a specific activity that was comparable with the commercial one. This study provides a new strategy for large-scale production of bioactive IL-22 for use in basic studies and therapeutic applications.


Assuntos
Interleucinas/isolamento & purificação , Interleucinas/metabolismo , Pichia/metabolismo , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Bioensaio , Células Hep G2 , Humanos , Interleucinas/farmacologia , Pichia/efeitos dos fármacos , Plasmídeos/genética , Proteínas Recombinantes/farmacologia , Transformação Genética/efeitos dos fármacos , Interleucina 22
16.
Int J Biol Macromol ; 146: 781-789, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31730959

RESUMO

The heterologous nature of SAK, a thrombolytic drug, elicits high titers of neutralizing antibodies, which limits its clinical use. Here, we aim to establish a SAK mutant with equivalent activity to the wild type but reduced antigenicity, which may allow for multiple injections. Biosun software was used to predict SAK antigenic epitopes, and several main epitopes were modified by gene deletion and mutation. Ten SAK mutants were constructed, and their thrombolytic activity and immunogenicity were analyzed in vitro. SAK6, with a high expression level (45%), similar thrombolytic activity, and lower antibody reaction, was chosen for in vivo analysis in rhesus monkey. In the nearly 8-month experimental period, the antibody level of the SAK6 group was significantly lower than that of the SAK group. Moreover, only 5% of SAK activity was retained, whereas 75.6% of SAK6 activity was retained after incubating with respective antiserum. Overall, these results demonstrated that SAK6, established through comprehensive site-directed mutagenesis program, had identical thrombolytic activity to SAK, low immunogenicity, and less side effects, demonstrating its efficient clinical potential for thrombus disease.


Assuntos
Fibrinolíticos/química , Fibrinolíticos/imunologia , Metaloendopeptidases/química , Metaloendopeptidases/genética , Metaloendopeptidases/imunologia , Animais , Anticorpos , Modelos Animais de Doenças , Epitopos , Feminino , Fibrinolíticos/farmacologia , Macaca mulatta , Masculino , Metaloendopeptidases/farmacologia , Mutagênese , Mutagênese Sítio-Dirigida , Mutação , Ratos , Ratos Wistar , Trombose
17.
Environ Pollut ; 256: 113342, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31676093

RESUMO

PM2.5 exposure aggravates type 2 diabetes, in which inflammatory factors play an important role. In this study, we aimed to explore the mechanisms responsible for aggravating diabetes after PM2.5 exposure, and study the roles of inflammatory factors in insulin-resistant type 2 diabetes. Our study indicated that short-time PM2.5 exposure enhances insulin resistance in type 2 diabetic rats and significantly raises inflammatory factors, including IL-6, TNF-α, and MCP-1, in lungs. However, we found that of these inflammatory factors only IL-6 levels are elevated in blood, liver, adipose tissue, and macrophages, but not in skeletal muscle. IL-6 induced activation of the STAT3/SOCS3 pathway in liver, but not other downstream pathways including STAT1, ERK1/2, and PI3K. Both STAT3 inhibition and IL-6 neutralization effectively alleviated the disorders of glucose metabolism after PM2.5 exposure. Taken together, this suggests that the systemic increase in IL-6 may play an important role in the deterioration of the type 2 diabetes via IL-6/STAT3/SOCS3 pathway in liver after short-time exposure to PM2.5. Besides, we unexpectedly found a stronger resistance to the PM2.5 exposure-induced increase in IL-6 in skeleton muscle than those of many other tissues.


Assuntos
Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Tipo 2/imunologia , Interleucina-6/sangue , Material Particulado/toxicidade , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Animais , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/metabolismo , Resistência à Insulina , Fígado/efeitos dos fármacos , Fígado/imunologia , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Masculino , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/imunologia , Material Particulado/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais
18.
Int J Biol Sci ; 16(1): 49-60, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31892845

RESUMO

PM2.5 exposure exacerbates cardiovascular diseases via oxidative stress and inflammation, the detailed mechanism of which is unclear. In this study, the effects of oxidative stress and inflammation, as well as vascular structure and function were studied by multiple PM2.5 exposure model of ApoE-/- mice. The results indicated that NO produced by iNOS not cNOS might play important roles in inducing vascular dysfunction after PM2.5 exposure. The occurrence order and causality among NO, other oxidative stress indicators and inflammation is explored by single PM2.5 exposure. The results showed that NO generated by iNOS occurred earlier than that of other oxidative stress indicators, which was followed by the increased inflammation. Inhibition of NOS could effectively block the raise of NO, oxidative stress and inflammation after PM2.5 exposure. All in all, we firstly confirmed that NO was the initiation factor of PM2.5 exposure-induced oxidative stress, which led to inflammation and the following vascular dysfunction.


Assuntos
Apolipoproteínas E/metabolismo , Inflamação/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Material Particulado/toxicidade , Animais , Apolipoproteínas E/genética , Western Blotting , Imuno-Histoquímica , Inflamação/genética , Interleucina-6/sangue , Masculino , Camundongos , Camundongos Mutantes , Óxido Nítrico Sintase Tipo II/genética , Estresse Oxidativo/efeitos dos fármacos , Fator de Necrose Tumoral alfa/sangue
19.
Neuro Oncol ; 22(12): 1797-1808, 2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-32492707

RESUMO

BACKGROUND: Glioblastoma stem cells (GSCs) are a subpopulation of glioblastoma (GBM) cells that are critical for tumor invasion and treatment resistance. However, little is known about the function and mechanism of tripartite motif-containing 24 (TRIM24) in GSCs. METHODS: Immunofluorescence, flow cytometry, and western blot analyses were used to evaluate TRIM24 and cluster of differentiation (CD)133 expression profiles in GBM surgical specimens and GSC tumorspheres. Different TRIM24 expression levels in patients' tumors, as measured by both immunohistochemistry and western blot, were related to their corresponding MRI data. Wound healing, Matrigel invasion, and xenograft immunohistochemistry were conducted to determine GBM cell invasion. RESULTS: We identified that TRIM24 was coexpressed with CD133 and Nestin in GBM tissues and tumorsphere cells. Limiting dilution assays and xenotransplantation experiments illustrated that knockdown of TRIM24 expression reduced GSC self-renewal capacity and invasive growth. TRIM24 expression levels were positively associated with the volumes of peritumoral T2 weighted image abnormality. Rescue experiments indicated TRIM24 participation in GBM infiltrative dissemination. Chromatin immunoprecipitation, reporter gene assay, PCR, western blot, and immunohistochemistry demonstrated that TRIM24 activated the expression of the pluripotency transcription factor sex determining region Y-box 2 (Sox2) to regulate GBM stemness and invasion in vitro and in vivo. Finally, the close relationship between TRIM24 and Sox2 was validated by testing samples enrolled in our study and exploring external databases. CONCLUSIONS: Our findings uncover essential roles of the TRIM24-Sox2 axis in GBM stemness and invasiveness, suggesting TRIM24 as a potential target for effective GBM management.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Neoplasias Encefálicas/genética , Proteínas de Transporte , Diferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Humanos , Células-Tronco Neoplásicas , Fatores de Transcrição SOXB1/genética
20.
Wei Sheng Yan Jiu ; 38(5): 516-21, 2009 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-19877503

RESUMO

OBJECTIVE: To explore TRPV1 UTR-3 polymorphism and susceptibility of childhood asthma of Han Nationality in Beijing. METHODS: 177 asthmatics, 44 atopy, and 151 control children less than 14-years-old were enrolled in case-control study, and all subjects were investigated by ISSAC questionnaires. Dominant, recessive, co-dominant, over-dominant, and log additive model were used to do genotype analysis, and LD analysis and haplotypes of SNPs were tested by Haploview 4.1. Hardy-Weinberg equilibrium test, Person chis-square test, linkage disequilibrium analysis, and logistic analysis were performed by SAS 9.1 software to determine the association between polymorphisms of TRPV1 and susceptibility of childhood asthma. RESULTS: Polymorphisms were found in rs402369, rs4790521, and rs4790522, Hardy-Weinberg P > 0.05. As to allele frequencies, frequency of SNP rs4790521 T/C in asthmatics were significantly increased (P < 0.05), no significant difference were found in MAF of rs402369 and rs4790522 (P > 0.05). Genotype analysis showed that rs4790521 C/C and rs4790522 A/C were associated with childhood asthma (P < 0.05), and odd ratios were 2.94 (1.32 - 6.53) and 0.588 (0.376 - 0.920) respectively. LD were found between rs4790521 and rs4790522, 3 haplotypes were built. Adjusted by age, gender, parent asthma history, and smoking exposure, logistic stepwise analysis showed that MAF of rs4790521, allozygote C/C of rs4790521, and haplotype C/C were associated with susceptibility to childhood asthma in Chinese Han Nationality in Beijing (P < 0.05). CONCLUSION: TRPV1 UTR-3 polymorphisms could be associated with the susceptibility to childhood asthma of Han Nation a city in Beijing.


Assuntos
Regiões 3' não Traduzidas/genética , Asma/genética , Predisposição Genética para Doença , Polimorfismo Genético , Canais de Cátion TRPV/genética , Estudos de Casos e Controles , Criança , China/etnologia , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino
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