Human embryonic fibroblasts （hEFs） can well maintain the pluripotency in human embryonic stem cells （hESs）. However, recent research and reports indicated that a few of hES cell lines acquired genomic alteration d...Human embryonic fibroblasts （hEFs） can well maintain the pluripotency in human embryonic stem cells （hESs）. However, recent research and reports indicated that a few of hES cell lines acquired genomic alteration during long-term culture of hES cells in vitro. This will directly restrict the therapy use of hES cells. Wnts are secreted lipid-modified signaling proteins that influence multiple processes ranging from cell proliferation to stem cell loss. Activation of Wnt signaling in many tissues has also been associated with cancer. Unchecked Wnt signaling and loss of cadherin expression can promote tumorigenesis. In this study, we found the caryotype of one hES cell line chHES-3 changed with duplication of 1 p32-1p36 area after 34 passages. The results of RT-PCR indicated Wnt7a was expressed in hEFs after culture normal karyotype hES cells, but not expressed in control and abnormal karyotype hES cells. Wnt3 was expressed in hEFs after culture abnormal karyotype hES cells, not expressed in control and normal karyotype hES cells. Wnt3, Wnt9a and WntlOb were detected weakly expression in normal hES cells, but higher in abnormal hES cells. At the same time, Wnt3a, Wnt4, Wnt5b, Wnt7a, Wnt8b and Wnt11 were expressed and E-cadherin was not tested in abnormal hES cells compared with normal hES cells. All that indicated Wnt7a was need for culture normal karyotype hES cells and Wnt3 was need for culture abnormal karyotype hES cells on hEFs. Wnt3, Wnt9a and WntlOb high expression in hES cells and absence of E-cadherin may cause hES cells karyotype change.展开更多
Influenza C virus, a member of the Orthomyxoviridae family, causes flu-like disease but typically only with mild symptoms. Humans are the main reservoir of the virus, but it also infects pigs and dogs. Very recently, ...Influenza C virus, a member of the Orthomyxoviridae family, causes flu-like disease but typically only with mild symptoms. Humans are the main reservoir of the virus, but it also infects pigs and dogs. Very recently, influenza C-like viruses were isolated from pigs and cattle that differ from classical influenza C virus and might constitute a new influenza virus genus. Influenza C virus is unique since it contains only one spike protein, the hemagglu- tinin-esterase-fusion glycoprotein HEF that possesses receptor binding, receptor destroying and membrane fusion activities, thus combining the functions of Hemaggiutinin （HA） and Neuraminidase （NA） of influenza A and B viruses. Here we briefly review the epidemiology and pathology of the virus and the morphology of virus particles and their genome. The main focus is on the structure of the HEF protein as well as on its co- and post- translational modification, such as N-glycosylation, disulfide bond formation, S-acylation and proteolytic cleavage into HEF1 and HEF2 subunits. Finally, we describe the functions of HEF： receptor binding, esterase activity and membrane fusion.展开更多
基金Acknowledgment This work was supported by grants from the National Nature Science Foundation of China （No.31071091 No.30971570） and Department of Education key project of Hunan Province, China （09A035 and 07B029）.
文摘Human embryonic fibroblasts （hEFs） can well maintain the pluripotency in human embryonic stem cells （hESs）. However, recent research and reports indicated that a few of hES cell lines acquired genomic alteration during long-term culture of hES cells in vitro. This will directly restrict the therapy use of hES cells. Wnts are secreted lipid-modified signaling proteins that influence multiple processes ranging from cell proliferation to stem cell loss. Activation of Wnt signaling in many tissues has also been associated with cancer. Unchecked Wnt signaling and loss of cadherin expression can promote tumorigenesis. In this study, we found the caryotype of one hES cell line chHES-3 changed with duplication of 1 p32-1p36 area after 34 passages. The results of RT-PCR indicated Wnt7a was expressed in hEFs after culture normal karyotype hES cells, but not expressed in control and abnormal karyotype hES cells. Wnt3 was expressed in hEFs after culture abnormal karyotype hES cells, not expressed in control and normal karyotype hES cells. Wnt3, Wnt9a and WntlOb were detected weakly expression in normal hES cells, but higher in abnormal hES cells. At the same time, Wnt3a, Wnt4, Wnt5b, Wnt7a, Wnt8b and Wnt11 were expressed and E-cadherin was not tested in abnormal hES cells compared with normal hES cells. All that indicated Wnt7a was need for culture normal karyotype hES cells and Wnt3 was need for culture abnormal karyotype hES cells on hEFs. Wnt3, Wnt9a and WntlOb high expression in hES cells and absence of E-cadherin may cause hES cells karyotype change.
文摘Influenza C virus, a member of the Orthomyxoviridae family, causes flu-like disease but typically only with mild symptoms. Humans are the main reservoir of the virus, but it also infects pigs and dogs. Very recently, influenza C-like viruses were isolated from pigs and cattle that differ from classical influenza C virus and might constitute a new influenza virus genus. Influenza C virus is unique since it contains only one spike protein, the hemagglu- tinin-esterase-fusion glycoprotein HEF that possesses receptor binding, receptor destroying and membrane fusion activities, thus combining the functions of Hemaggiutinin （HA） and Neuraminidase （NA） of influenza A and B viruses. Here we briefly review the epidemiology and pathology of the virus and the morphology of virus particles and their genome. The main focus is on the structure of the HEF protein as well as on its co- and post- translational modification, such as N-glycosylation, disulfide bond formation, S-acylation and proteolytic cleavage into HEF1 and HEF2 subunits. Finally, we describe the functions of HEF： receptor binding, esterase activity and membrane fusion.
