Time filter

Source Type

Xiao W.,Second Clinical Medical College | Xiao W.,Jiangsu Key Laboratory of Integrated Traditional Chinese | Wu K.,Second Clinical Medical College | Wu K.,Jiangsu Key Laboratory of Integrated Traditional Chinese | And 12 more authors.
Journal of Immunotherapy | Year: 2015

Wogonin exerts effective antitumor activities through direct cytotoxicity against cancer cells and indirect immune modulation. However, the molecular mechanisms of these activities remain poorly understood and need further study. We found that wogonin could efficiently downregulate the expression of B7H1, retinoic acid early induced transcript-1ε (RAE-1ε), and vascular endothelial growth factor in gastric cancer cells. Wogonin also promoted the secretion of calreticulin and high-mobility group protein 1 by tumor cells. Apoptotic bodies from dying tumor cells treated with wogonin were susceptible for uptake by neighboring dendritic cells (DCs). With the xenograft tumor model, wogonin inhibited tumor growth and promoted the recruitment of DC, T, and NK cells into tumor tissues. Infiltrated frequencies of DC, T, and NK cells in tumors were inversely correlated with expression levels of vascular endothelial growth factor, B7H1, and RAE-1ε of tumor tissues. Wogonin directly inhibited the activation of STAT3 on tyrosine 705 in tumor cells. The dephosphorylation of STAT3 contributed to the decreased expression of B7H1 and MHC class I chain-related protein A, and the enhancement of calreticulin on the cell membrane. Our study confirmed the immune-enhancing function of wogonin, and indicated that wogonin could be used in collaboration with DC vaccine or activated lymphocytes for tumor therapy. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. Source

Qian L.,Yangzhou University | Qian L.,Jiangsu Electric Power Company | Qian L.,Jiangsu Key Laboratory of Integrated Traditional Chinese | Chen W.,Yangzhou University | And 7 more authors.
Microbiology and Immunology | Year: 2015

Because inappropriate activation of Toll-like receptor9 (TLR9) may induce pathological damage, negative regulation of the TLR9-triggered immune response has attracted considerable attention. Nonpathogenic immune complex (IC) has been demonstrated to have beneficial therapeutic effects in some kinds of autoimmune diseases. However, the role of IC in the regulation of TLR9-triggered immune responses and the underlying mechanisms remain unclear. In this study, it was demonstrated that IC stimulation of B cells not only suppresses CpG-oligodeoxynucleotide (CpG-ODN)-induced pro-inflammatory IL-6 and IgM κ production, but also attenuates CD40 and CD80 expression. Furthermore, our results suggest that the receptor for the Fc portion of IgG (FcγR) IIb is involved in the suppressive effect of IC on TLR9-mediated CD40, CD80 and IL-6 expression. Finally, it was found that IC down-regulates TLR9 expression in CpG-ODN activated B cells. Our results provide an outline of a new pathway for the negative regulation of TLR9-triggered immune responses in B cells via FcγRIIb. A new mechanistic explanation of the therapeutic effect of nonpathogenic IC on inflammatory and autoimmune diseases is also provided. © 2015 The Societies and Wiley Publishing Asia Pty Ltd. Source

Li Q.,Yangzhou University | Li X.,Yangzhou University | Wang C.,Yangzhou University | Wang C.,Jiangsu Key Laboratory of Integrated Traditional Chinese | Wang C.,Jiangsu Electric Power Company
Neoplasma | Year: 2016

Ultraconserved regions (UCRs) are non-protein coding gene sequences with strict conserved across among different species. Emerging evidence demonstrates that UCRs encoding noncoding RNAs (ncRNAs) serve as regulators of gene expression. In recent decades, increasing evidence implicates the involvement of UCRs in carcinogenesis. Previous studies showed RNA expression of uc.206 was increased in colorectal cancer. Until now, the role of uc.206 in cervical cancers remains undefined. This study revealed that uc.206 is significantly up-regulated in cervical cancer (CC) tissue and negatively correlates with the expression of the pro-apoptotic gene P53 in RNA level. We show that uc.206 specifically targets the 3’ untranslated region (3’UTR) of P53 and regulates its expression. Inhibition of uc.206 effectively delays cervical cells proliferation and promotes apoptosis, accompanied by increased expression of P53 protein. Thus, these findings suggested that uc.206 acts as a novel oncogene by targeting the P53 gene and promoting CC cell growth, which might be beneficial for cervical cancer therapy. © 2016, Cancer Research Institute Slovak Acad. of Sciences. All rights reserved. Source

Wan Q.,Jiangsu Key Laboratory of Integrated Traditional Chinese | Wan Q.,Jiangsu Electric Power Company | Wan Q.,Yangzhou University | Bennett B.C.,University of Virginia | And 5 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014

Dihydrofolate reductase (DHFR) catalyzes the NADPH-dependent reduction of dihydrofolate (DHF) to tetrahydrofolate (THF). An important step in the mechanism involves proton donation to the N5 atom of DHF. The inability to determine the protonation states of active site residues and substrate has led to a lack of consensus regarding the catalytic mechanism involved. To resolve this ambiguity, we conducted neutron and ultrahigh-resolution X-ray crystallographic studies of the pseudo-Michaelis ternary complex of Escherichia coli DHFR with folate and NADP+. The neutron data were collected to 2.0-A˚ resolution using a 3.6-mm3 crystal with the quasi-Laue technique. The structure reveals that the N3 atom of folate is protonated, whereas Asp27 is negatively charged. Previous mechanisms have proposed a keto-to-enol tautomerization of the substrate to facilitate protonation of the N5 atom. The structure supports the existence of the keto tautomer owing to protonation of the N3 atom, suggesting that tautomerization is unnecessary for catalysis. In the 1.05-A˚ resolution X-ray structure of the ternary complex, conformational disorder of the Met20 side chain is coupled to electron density for a partially occupied water within hydrogen-bonding distance of the N5 atom of folate; this suggests direct protonation of substrate by solvent. We propose a catalytic mechanism for DHFR that involves stabilization of the keto tautomer of the substrate, elevation of the pKa value of the N5 atom of DHF by Asp27, and protonation of N5 by water that gains access to the active site through fluctuation of the Met20 side chain even though the Met20 loop is closed. © 2014, National Academy of Sciences. All rights reserved. Source

Wang C.,Yangzhou University | Wu X.,Yangzhou University | Shen F.,Yangzhou University | Li Y.,Yangzhou University | And 4 more authors.
Development Growth and Differentiation | Year: 2015

Long noncoding RNAs (LncRNAs) are longer than 200 nucleotide noncoding RNAs without apparent functional coding capacity that function as regulators of cell growth and development. In recent years, increasing evidence implicates the involvement of LncRNAs in erythropoiesis. shlnc-EC6 is a LncRNA associated with erythroid differentiation but the mechanism remains undefined. In this study, we found that knockdown of shlnc-EC6 in purified mouse fetal liver erythroid progenitor and hematopoietic stem cells (FLEPHSCs) significantly blocked erythroid enucleation. We also showed that Rac1 was negatively regulated by shlnc-EC6 at the posttranscriptional level via specific binding to sites within the 3'UTR of Rac1 mRNA. Moreover, we found that knockdown of shlnc-EC6 led to upregulation of Rac1, followed by the activation of the downstream protein PIP5K, and subsequently resulted in the inhibition of enucleation in cultured mouse fetal erythroblasts. Thus, our findings suggest that shlnc-EC6 acts as a novel modulator to regulate mouse erythropoiesis via Rac1/PIP5K signaling pathway. © 2015 Japanese Society of Developmental Biologists. Source

Discover hidden collaborations