Prion diseases are a group of neurodegenerative diseases that are fatal. The study of these unique diseases in China is hampered by a lack of resources. Amongst the most important resources for biological study are mo...Prion diseases are a group of neurodegenerative diseases that are fatal. The study of these unique diseases in China is hampered by a lack of resources. Amongst the most important resources for biological study are monoclonal antibodies. Here, we characterize a panel of monoclonal antibodies specific for cellular prion protein by enzyme-linked immunosorbent assay(ELISA), immunofluorescent staining, flow cytometry, and western blotting. We identify several antibodies that can be used for specific applications and we demonstrate that there is no prion protein expression in human pancreatic ductal epithelial cells(HPDC).展开更多
Tumor Necrosis Factor α(TNFα) is best known as a mediator of inflammation and immunity, and also plays important roles in tumor biology. However, the role of TNFα in tumor biology is complex and not completely unde...Tumor Necrosis Factor α(TNFα) is best known as a mediator of inflammation and immunity, and also plays important roles in tumor biology. However, the role of TNFα in tumor biology is complex and not completely understood. In a human melanoma cell line, M2, and a lung carcinoma cell line, A549, TNFα up-regulates prion protein(PrP) level, and promotes tumor cell migration in a PrP dependent manner. Silencing PRNP abrogates TNFα induced tumor cell migration;this phenotype is reversed when PRNP is re-introduced. Treatment with TNFα activates nuclear factor kappa B(NF-κB)signaling, which then mitigates autophagy by reducing the expression of Forkhead Box P3(FOXP3). Down regulation of FOXP3 reduces the transcription of synaptosome associated protein 29(SNAP29), which is essential in the fusion of autophagosome and lysosome creating autolysosome. FOXP3 being a bona fide transcription factor for SNAP29 is confirmed in a promoter binding assay. Accordingly, silencing SNAP29 in these cell lines also up-regulates PrP, and promotes tumor cell migration without TNFα treatment. But, when SNAP29 or FOXP3 is silenced in these cells, they are no longer respond to TNFα. Thus, a reduction in autophagy is the underlying mechanism by which expression of PrP is up-regulated,and tumor cell migration is enhanced upon TNFα treatment. Disrupting the TNFα-NF-κB-FOXP3-SNAP29 signaling axis may provide a therapeutic approach to mitigate tumor cell migration.展开更多
基金the National Natural Sciences Foundation of China(81172376,31270209)the 100 talent-program of the Chinese Academy of Sciencesthe State Key Laboratory of Virology for financial support
文摘Prion diseases are a group of neurodegenerative diseases that are fatal. The study of these unique diseases in China is hampered by a lack of resources. Amongst the most important resources for biological study are monoclonal antibodies. Here, we characterize a panel of monoclonal antibodies specific for cellular prion protein by enzyme-linked immunosorbent assay(ELISA), immunofluorescent staining, flow cytometry, and western blotting. We identify several antibodies that can be used for specific applications and we demonstrate that there is no prion protein expression in human pancreatic ductal epithelial cells(HPDC).
基金supported by grants from the National Science Foundation of China (31670170 & 81560442)from MOST (2018YFA0507201)from the Natural Science Foundation of Guangdong Province (2017ZC0236)。
文摘Tumor Necrosis Factor α(TNFα) is best known as a mediator of inflammation and immunity, and also plays important roles in tumor biology. However, the role of TNFα in tumor biology is complex and not completely understood. In a human melanoma cell line, M2, and a lung carcinoma cell line, A549, TNFα up-regulates prion protein(PrP) level, and promotes tumor cell migration in a PrP dependent manner. Silencing PRNP abrogates TNFα induced tumor cell migration;this phenotype is reversed when PRNP is re-introduced. Treatment with TNFα activates nuclear factor kappa B(NF-κB)signaling, which then mitigates autophagy by reducing the expression of Forkhead Box P3(FOXP3). Down regulation of FOXP3 reduces the transcription of synaptosome associated protein 29(SNAP29), which is essential in the fusion of autophagosome and lysosome creating autolysosome. FOXP3 being a bona fide transcription factor for SNAP29 is confirmed in a promoter binding assay. Accordingly, silencing SNAP29 in these cell lines also up-regulates PrP, and promotes tumor cell migration without TNFα treatment. But, when SNAP29 or FOXP3 is silenced in these cells, they are no longer respond to TNFα. Thus, a reduction in autophagy is the underlying mechanism by which expression of PrP is up-regulated,and tumor cell migration is enhanced upon TNFα treatment. Disrupting the TNFα-NF-κB-FOXP3-SNAP29 signaling axis may provide a therapeutic approach to mitigate tumor cell migration.
