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1.
Biochim Biophys Acta Mol Basis Dis ; 1864(2): 387-397, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29097259

RESUMO

Chemokines and chemokine receptors play an important role in tumorigenesis. Angiogenesis is a vital part of the occurrence, development and metastasis of cancer. CCR6 is an important factor during tumor progression; however, its function in tumor angiogenesis is not fully understood. In our study, we found that CCR6 was significantly overexpressed in colorectal cancer (CRC) tissues and predicted a poor prognosis in CRC patients. We then verified the function of CCR6 on tumor angiogenesis in vivo and in vitro. We observed that silencing CCR6 could decrease angiogenesis by inhibiting the proliferation and migration of human umbilical vein endothelial cells (HUVECs), whereas overexpression of CCR6 can promote angiogenesis. Additionally, we investigated the molecular mechanisms and demonstrated that activation of the AKT/NF-κB pathway maybe involved in CCR6-mediated tumor angiogenesis, which was able to promote the secretion of vascular endothelial growth factor A (VEGF-A). In conclusion, CCR6 facilitates tumor angiogenesis via the AKT/NF-κB/VEGF pathway in colorectal cancer. CCR6 inhibition may be a novel option for anti-vascular treatment in CRC.


Assuntos
Neoplasias Colorretais/metabolismo , NF-kappa B/metabolismo , Neovascularização Patológica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores CCR6/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Idoso , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Progressão da Doença , Matriz Extracelular/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Células HT29 , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade
2.
Huan Jing Ke Xue ; 37(4): 1330-6, 2016 Apr 15.
Artigo em Chinês | MEDLINE | ID: mdl-27548953

RESUMO

Mercury is harmful to the environment, which has gradually become one of the research hotspots. Sediments, as a main repository of pollutants, have an important impact on water quality and the internal organisms, which deserves our research. In this paper, we focused on Hefei landscape water sediment and tried to investigate the status of inorganic mercury and methylmercury pollutions in the sediment. To study the conversion process from inorganic mercury to methylmercury and their enrichment levels and mechanism, we established the ecological chain of "sediment-water-grass-fish" through analog microcosm examination. The results were as follows: from ten water and sediment samples in Hefei landscape water sediment, we found that the contents of inorganic mercury and methylmercury ranged 11.74-13.12 µg · kg⁻¹ and 0.37-2.23 µg · kg⁻¹, respectively. The microcosm examination showed that: with increasing culture time, inorganic mercury in sediments gradually decreased. There was a phenomenon that the content of methylmercury increased at first and then decreased to reach the balance later. Both the inorganic mercury and methylmercury in water change showed an increasing trend. The enrichment contents of inorganic mercury in Egeria densa Planch, and golden mandarin fish (Siniperca scherzeri Steindachner) were low while their enrichment of methylmercury could he great. In addition, we found that both the bioaccumulation ability and the enrichment coefficient of methylmercury in the body of golden mandarin fish were the maximum during the same period.


Assuntos
Monitoramento Ambiental , Mercúrio/análise , Compostos de Metilmercúrio/análise , Poluentes Químicos da Água/análise , Animais , Peixes , Sedimentos Geológicos/química , Masculino , Poaceae/química , Água/química
3.
Mar Biotechnol (NY) ; 16(5): 538-46, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24763817

RESUMO

Plastids are ideal subcellular hosts for the expression of transgenes and have been successfully used for the production of different biopolymers, therapeutic proteins and industrial enzymes. Phaeodactylum tricornutum is a widely used aquatic feed species. In this study, we focused on developing a high-efficiency plastid expression system for P. tricornutum. In the plastid transformation vector, the site selected for integration was the transcriptionally active intergenic region present between the trnI and trnA genes, located in the IR (inverted repeat) regions of the plastid genome. Initially, a CAT reporter gene (encoding chloramphenicol acetyltransferase) was integrated at this site in the plastid genome. The expression of CAT in the transformed microalgae conferred resistance to the antibiotic chloramphenicol, which enabled growth in the selection media. Overall, the plastid transformation efficiency was found to be approximately one transplastomic colony per 1,000 microalgae cells. Subsequently, a heterologous gene expression cassette for high-level expression of the target gene was created and cloned between the homologous recombination elements. A TA cloning strategy based on the designed XcmI-XcmI sites could conveniently clone the heterologous gene. An eGFP (green fluorescent protein) reporter gene was used to test the expression level in the plastid system. The relatively high-level expression of eGFP without codon optimisation in stably transformed microalgae was determined to account for 0.12 % of the total soluble protein. Thus, this study presents the first and convenient plastid gene expression system for diatoms and represents an interesting tool to study diatom plastids.


Assuntos
Cloroplastos/genética , Diatomáceas/genética , Vetores Genéticos/genética , Transformação Genética/genética , Western Blotting , Cloranfenicol , Mapeamento Cromossômico , Clonagem Molecular , Primers do DNA/genética , Resistência Microbiana a Medicamentos/genética , Eletroporação , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Genes Reporter/genética , Proteínas de Fluorescência Verde/genética , Microscopia Confocal , Reação em Cadeia da Polimerase em Tempo Real
4.
Opt Lett ; 38(17): 3202-4, 2013 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-23988913

RESUMO

A compact fiber tip modal interferometer (FTMI) based on two-wave interference has been demonstrated. Its fabrication process is very simple, just involving fiber tapering by a fusion splicer. The effective sensing area of the FTMI has a small length of ~310 µm. The interference spectra of the fiber tips with different size and profile have been analyzed. The FTMI has a good mechanical strength and high-temperature stability. It can be used for high-temperature and transverse load sensing simultaneously in a harsh environment when two different attenuation peaks are chosen to be monitored.


Assuntos
Interferometria/instrumentação , Fibras Ópticas , Temperatura , Luz
5.
Opt Lett ; 38(8): 1209-11, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23595433

RESUMO

We demonstrate an ultrasensitive temperature sensor based on an isopropanol-sealed optical microfiber taper (OMT) in a capillary. The OMT is highly sensitive to ambient refractive index (RI) with a maximum sensitivity of 18989 nm/RI unit in the range of 1.3955-1.4008. The thermo-optic effect of isopropanol and the thermal expansions of the sealant and sealed liquid turn the OMT into an ultrasensitive temperature sensor with the maximum sensitivity of -3.88 nm/°C in the range of 20°C-50°C. The temperature sensitivity contributions from different mechanisms are also investigated theoretically and experimentally.

6.
Biotechniques ; 52(6)2012 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-26307256

RESUMO

Diatoms are important primary producers in the marine ecosystem. Currently it is difficult to genetically transform diatoms due to the technical limitations of existing methods. The promoter/terminator of the nitrate reductase gene of the model diatom Phaeodactylum tricornutum was cloned and used to drive chloramphenicol acetyltransferase (CAT) reporter gene expression. The construct was transferred by electroporation into P. tricornutum grown in medium lacking silicon. CAT expression was induced in transformed diatoms in the presence of nitrate, enabling growth in selective medium, and was repressed when ammonium was the only nitrogen source. Expression of CAT transcript and protein were demonstrated by RT-PCR and Western blot analysis, respectively. Our study is the first to report a successful genetic transformation of diatom by electroporation in an economical and efficient manner and provides a tightly regulated inducible gene expression system for diatom.


Assuntos
Diatomáceas/enzimologia , Diatomáceas/genética , Eletroporação/métodos , Regiões Promotoras Genéticas/genética , Transformação Genética/genética , Biotecnologia , Cloranfenicol O-Acetiltransferase/metabolismo , Clonagem Molecular , Diatomáceas/metabolismo , Vetores Genéticos/genética , Nitrato Redutase/genética , Nitrato Redutase/metabolismo
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