Yuqing Shen

Southeast University (China), Nan-ching-hsü, Jiangxi Sheng, China

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Publications (11)27.5 Total impact

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    ABSTRACT: Core-shell mesoporous silica (MPS) materials have been proven to perform multiple simultaneous functions in biological systems and they demonstrate a vast potential for applications in the medical arena. Exploring such extensive potential requires a meticulous evaluation of their interactions with cells. The aim of this study is to investigate the influence of MPS-shells on the viability and activation of human THP-1 macrophages by comparing core-shell MPS with colloidal silica particles. In the present study we find core-shell MPS particles with a solid colloidal silica core and a thin MPS-shell deliver significantly less cytotoxicity than their nonporous counterparts and induce lower expression and release of the pro-inflammatory cytokines in macrophages. Moreover, core-shell MPS particles show no effect on the activation of mitogen-activated protein kinases (MAPKs), while colloidal silica particles do activate MAPKs under identical conditions. The corona of core-shell MPS particles is composed of a greater amount and variety of proteins as compared with colloidal silica particles. The abundant protein composition of the corona may inhibit the cellular toxicity by masking surface silanol groups at the MPS-cellular interface. In conclusion, the MPS-shell significantly alleviates both cytotoxicity and immune responses induced by colloidal silica particles while greatly improving the biocompatibility of colloidal silica materials.
    Colloids and surfaces B: Biointerfaces 01/2014; 116:334–342. · 4.28 Impact Factor
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    ABSTRACT: The major histocompatibility complex (MHC) class I molecules are considered to be important in the immune system. However, the results reported in the past decade indicate that they also play important roles in the central nervous system. Here we examined the expression of MHC I and β2-microglobulin (β2m) in human and mouse cerebellar cortex. The results show that MHC I molecules are expressed both in human and mouse cerebellar cortex during brain development. The expression of H-2K(b)/D(b) is gradually increased with the development of mouse cerebellar cortex, but finally decreased to a very low level. Similarly, the expression of HLA-B/C genes is increased in developing human cerebellar cortex, but decreased after birth. The spatial and temporal expression of β2m overlaps mostly with that of HLA-B/C molecules, and they are co-expressed in Purkinje cells. Our findings provide a fundamental basis to reveal the functions of neuronal MHC class I molecules in the development of human cerebellum.
    Neurochemical Research 11/2013; · 2.13 Impact Factor
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    ABSTRACT: In the immune system, the major histocompatibility complex (MHC) class I molecules mediate both the innate and adaptive immune responses in vertebrates. There has been a dogma that the central nervous system (CNS) is immune privileged and healthy neurons do not express MHC class I molecules. However, recent studies have indicated that the expression and non-immunobiologic roles of MHC class I in mammalian CNS. But data referring to humans are scarce. In this study we report the expression and cellular localization of MHC class I in the human fetal, early postnatal and adult hippocampal formation. The expression of MHC class I was very low in the hippocampus at 20 (gestational weeks) GW and slowly increased at 27-33GW. The gradually increased expression in the somata of some granular cells in dentate gyrus (DG) was observed at 30GW-33GW. Whereas, a rapid increase in MHC class I molecules expression was found in the subiculum and it reached high levels at 31-33GW and maintained at postnatal 55 days. No expression of MHC class I was found in hippocampal formation in adult. MHC class I heavy chain and β2 microglobulin (β2M) showed similar expression in some cells of the hippocampal formation at 30-33GW. Moreover, MHC class I molecules were mainly expressed in neurons and most MHC class I-expressing neurons were glutamatergic. The temporal and spatial patterns of MHC classⅠexpression appeared to follow gradients of pyramidal neurons maturation in the subiculum at prenatal stages and suggested that MHC classⅠmolecules are likely to regulate neuron maturation.
    Brain research 07/2013; · 2.46 Impact Factor
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    ABSTRACT: Aim. To investigate whether HLA class I polymorphisms could influence the clearance of hepatitis B surface antigen (HBsAg) in Qidong Han population. Methods. We genotyped HLA-A, -B, and -C loci of 448 individuals with HBV persistent infection and 140 persons with spontaneous clearance of HBsAg by polymerase chain reaction with sequencing based typing (PCR/SBT). All the individuals were unrelated males enrolled from Qidong Han population and were followed up for 10 years. Results. The frequency of HLA-A∗33:03:01G was increased in persistent HBV infection group (P value is 0.028), while frequency of HLA-B∗13:01:01G was increased in HBsAg clearance group (P value is 0.0004). Conclusion. These findings suggested that the host HLA class I polymorphism is an important factor in determining the outcomes of HBV infection.
    Clinical and Developmental Immunology 01/2013; 2013:145725. · 3.06 Impact Factor
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    ABSTRACT: Classical major histocompatibility complex (MHC) class I, first identified in the immune system, is also expressed in the developing and adult central nervous system (CNS). Although the MHC class I molecules have been found to be expressed in the CNS of different species, a necessary step to elucidate the temporal and spatial expression patterns of MHC class I molecules in the brain development has never been taken. Frozen sections were made from the brains of embryonic and postnatal C57BL/6 J mice, and the expression of H-2D(b) mRNA was examined by in situ hybridization. Immunofluorescence was also performed to define the cell types that express H2-D(b) in P15 mice. At E10.5, the earliest stage we examined, H2-D(b) was expressed in neuroepithelium of the brain vesicles. From E12.5 to P0, H2-D(b) expression was mainly located at cerebral cortex, neuroepithelium of the lateral ventricle, neuroepithelium of aquaeductus and developing cerebellum. From P4 to adult, H2-D(b) mRNA was detected at olfactory bulb, hippocampus, cerebellum and some nerve nuclei. The major cell types expressing H-2D(b) in P15 hippocampus, cerebral cortex and olfactory bulb were neuron. H2-K(b) signal paralleled that of H2-D(b) and the expression levels of the two molecules were comparable throughout the brain. The investigation of the expression pattern of H-2D(b) at both embryonic and postnatal stages is important for further understanding the physiological and pathological roles of H2-D(b) in the developing CNS.
    Neurochemical Research 11/2012; · 2.13 Impact Factor
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    ABSTRACT: It has been considered that healthy neurons in central nervous system (CNS) do not express major histocompatibility complex (MHC) class I molecules. However, recent studies clearly demonstrated the expression of functional MHC class I in the mammalian embryonic, neonatal and adult brain. Until now, it is still unknown whether MHC I molecules are expressed in the development of human brain. We collected nine human brain tissues from fetuses aged from 21 to 31 gestational weeks (GW), one newborn of postnatal 55 days and one adult. The expression of MHC class I molecules was detected during the development of visual system in human brain by immunohistochemistry and immunofluorescence. MHC class I proteins were located at lateral geniculate nucleus (LGN) and the expression was gradually increased from 21 GW to 31 GW and reached high levels at 30-31 GW when fine-scale refinement phase was mediated by neural electric activity. However, there was no expression of MHC class I molecules in the visual cortical cortex during all the developmental stages examined. We also concluded that MHC class I molecules were mainly expressed in neurons but not in astrocytes at LGN. In the developing visual system, the expression of β2M protein on neurons was not found in our study.
    Neurochemical Research 11/2012; · 2.13 Impact Factor
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    ABSTRACT: Tremor disease (TD) has been found to be a lethal epidemic in Chinese mitten crab during recent years. A new species of spiroplasma, Spiroplasma eriocheiris (S. eriocheiris), was identified as the pathogen causing TD. In order to acquire appropriate biological tools for characterizing this newly discovered pathogen, we developed a new S. eriocheiris specific monoclonal antibody (mAb) 6H7. The antibody showed high binding affinity to S. eriocheiris (K(a)=6.25×10(8)M(-1)) and it bound to the adhesin-like protein (ALP41) of S. eriocheiris in Western blot analysis. Screening of a commercially available 12-mer linear peptide library by using 6H7 as bait led to isolation of a consensus sequence (FQGINHYNQMER). The clone displaying this sequence exhibited a significant, dose-dependent binding to 6H7 and inhibited the binding of S. eriocheiris to 6H7, suggesting a similar epitope between the sequence and S. eriocheiris. Homology searches and multiple sequence alignments indicated moderate homology between the consensus peptides and the ALP of S. eriocheiris. Thus, an internal image of 6H7 binding epitope might be buried in ALP41 of S. eriocheiris. In conclusion, 6H7 is a promising mAb to identify S. eriocheiris and the consensus sequence can be used in future research on the characterization of S. eriocheiris and its pathogenesis.
    Veterinary Microbiology 08/2012; · 3.13 Impact Factor
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    ABSTRACT: Current studies are ongoing to find new drugs for the treatment of hepatocellular carcinoma (HCC). The discovery of drugs depends on the identification of molecules that can play essential roles in the development of liver cancer, for example, Notch pathway molecules. γ-Secretase inhibitors (GSIs) can inhibit the cleavage of intramembranous substrates of all Notch receptors and subsequently suppress Notch signaling. However, whether the inhibition of the Notch pathway can suppress or promote HCC growth is still under debate. In this study, we examined the expression of Notch pathway molecules in 20 pairs of HCC tissue with their normal counterparts and a panel of eight HCC cell lines. We also determined the effects of different types of GSI treatments on the cell growth of those HCC cell lines. Our results showed that the molecules of the Notch pathway were expressed in six of the eight HCC cell lines. Those six HCC cell lines were more sensitive to GSI-I treatment than the nonexpression ones. Among the four inhibitors, GSI-X and GSI-XXI exerted no effect on HCC cells growth at all. GSI-IX inhibited the growth of four HCC cell lines at 40 μmol/l. In contrast, most of these HCC cell lines were susceptible to a low concentration of GSI-I (1.2 μmol/l) treatment. The suppressive effect of GSI-I on cell growth was because of the inhibition of C-Myc, a Notch target gene. In addition, 80% (16/20) of the specimens showed either an increased expression of at least one Notch receptor or an augmented expression of Jagged1 compared with their normal counterparts. Our study reports for the first time that different kinds of GSIs can block the growth of several HCC cell lines. Our finding suggests that GSI-I is a potential chemical reagent and warrants additional testing in liver cancer therapeutics.
    Anti-cancer drugs 05/2012; 23(7):683-90. · 2.23 Impact Factor
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    ABSTRACT: The heavy chain protein of HLA-peptide complexes (HLA/HBc(18-27) and HLA/CEA(694-702)) immobilized onto an ion exchange chromatography column and then the dilution-refolded HBc(18-27)-fused or CEA(694-702)-fused β2m protein was able to pass through the column. Using this method, HLA/peptide complexes were prepared within 30 h with a refolding yield of at least 20% (w/w) and purity of over 80% (w/w). This strategy refolds, concentrates, and purifies HLA/peptide complexes in a single integrated step and offers a potential tool to refold multiple-subunit proteins other than the major histocompatibility complex (MHC)/peptide complexes.
    Biotechnology Letters 12/2010; 32(12):1803-8. · 1.85 Impact Factor
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    ABSTRACT: Chronic hepatitis B virus infection is associated with a high risk of developing into hepatocellular carcinoma, while tumor recognition is important during the immune surveillance process that prevents cancer development in humans. The mechanisms of immune evasion and the role of the early immune response in chronic infection caused by hepatitis B virus (HBV) are still unclear. In the present study, 1 copy or 1.2 copies of HBV genome was transfected into a hepatocellular carcinoma cell line BEL7405. RT-PCR, Western blot and flow cytometry analysis were used to evaluate the expression of HLA class I molecules and transporter associated with antigen processing 1 (TAP1). Finally, the cytotoxic activity of natural killer (NK) cells against HBV transfected liver cells was detected by MTT colorimetry method. Following transfection of 1 copy or 1.2 copies of HBV genome, HLA class I expression was up-regulated in BEL7405 cell line in a dose-dependent manner. Furthermore, increased the surface HLA class I expression were caused by enhanced expression of TAP1 at mRNA and protein levels in those transfected cells. Consequently, a significantly down-regulated cytotoxic activity of NK cells against HBV transfected liver cells was observed. These results may demonstrate a way by which HBV avoids recognition by NK cells that might be associated with the establishment of chronic infection and tumor formation.
    Immunological Investigations 01/2010; 39(6):621-34. · 1.47 Impact Factor
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    ABSTRACT: Malignant transformation of hepatocytes is frequently associated with upregulation of HLA-A expression. Currently there is no information available regarding the mechanisms underlying this phenotypic change. We investigated HLA-A expression in 165 paraffin embedded tissues and 21 fresh tissues from liver cancer patients. Utilizing truncated HLA-A promoter-reporter constructs and gel-shift assay we had identified the regulatory elements and transcription factors required for HLA-A upregulation. 54% of the paraffin embedded tissues showed increased HLA-A expression in their cancerous part. 43% of the fresh liver cancer tissues had increased HLA-A complex expression with the HLA-A heavy chain gene demonstrating the highest level of upregulation (62%). Enhanced HLA-A expression in the liver cell lines QGY7701 and BEL7402 was found to be mediated by binding of interferon regulatory factor 1 (IRF-1) to interferon stimulated response element, and of nuclear transcription factor p65 binding to enhancer A element in the HLA-A promoter of these cell lines. The in vivo relevance of these findings was indicated by the association of the enhanced expression of IRF-1 and accumulation of nuclear p65 with HLA-A upregulation in 8 of the 21 liver cancer lesions investigated. Our results indicated that HLA-A upregulation in liver cancer was mediated by both increased nuclear aggregation of transcription factor p65 and upregulation of transcription factor IRF-1.
    Molecular Immunology 07/2009; 46(10):2045-53. · 2.65 Impact Factor