Although VEGFR-3 deficiency disrupts blood vascular development during early embryogenesis, the underlying mechanism was not clear. To characterize its function in angiogenesis and lymphangiogenesis, we employed two g...Although VEGFR-3 deficiency disrupts blood vascular development during early embryogenesis, the underlying mechanism was not clear. To characterize its function in angiogenesis and lymphangiogenesis, we employed two genetically modified mouse models in this study, targeting the coding region for the ligand-binding domain （Vegfr△LBD） or the tyrosine kinase domain with an inactivation point mutation （Vegfr3^TKmat）. We show that lymphatic growth was disrupted in Vegfr3△LBD/△LBD and Vegfr3^TKmut3^TKmat mice, but blood vessels developed normally in both embryo and yolk sac. Interestingly, in Vegfr3△LBD/△LBD but not Vegfr3^TKmut3^TKmat mice, lymph sac was present but there was lack of iym- phangiogenic sprouting. We further demonstrate that both the wild-type and mutant forms of VEGFR-3 could form heterodimers with VEGFR-2, and decreased the level of phospho-VEGFR-2 and the downstream phospho-Erk1/2 in endothelial cells when they were treated with VEGF-A. These findings indicate that signaling mediated via VEGFR-3 activation by its cognate ligands （VEGF-C/-D） is not required for angiogenesis, and that VEGFR-3 may play a role in this process by modulating VEGFR-2-mediated signals.展开更多
Interest in ion channels as drug targets for contraception has grown with the realization that certain ion channel subunits are located exclusively in sperm. Selective knockdown of ion channel subunits can lead to inf...Interest in ion channels as drug targets for contraception has grown with the realization that certain ion channel subunits are located exclusively in sperm. Selective knockdown of ion channel subunits can lead to infertility without ill effects, and selective inhibitors and/ or openers of these ion channels could interfere with sperm function. In this study, in vivo electmporation （EP） and rete testis microinjection-mediated plasmid DNA were adopted to silence CatSper2 expression, which is essential in sperm hyperactivation. The results showed that high transfection efficiency and expression were achieved by plasmid DNA that was directly injected into the rete testis. As a result of the expression of CatSper2 being blocked, the treatment group showed significantly lower （P〈0.05） hyperactivation rate, fertilization rate in vitro, migration motility in viscoelastic solution and intracellular Ca2＋ peak. The low hyperactivation and fertilization rates lasted for 60 days. Meanwhile, analysis of the sperm survival rate and testis histology indicated that in vivo EP had no significant effect on the function of the testis, spermatogenesis or sperm activity. The present study demonstrated that it was feasible to achieve male contraception by silencing the expression of CatSper2, the key protein involved in sperm hvoeractivation.展开更多
In order to investigate immunogenicity in the induction of humoral and cellular immune responses, severe acute respiratory syndrome associated coronavirus （SARS-CoV）-N gene recombinant replication-defective adenovir...In order to investigate immunogenicity in the induction of humoral and cellular immune responses, severe acute respiratory syndrome associated coronavirus （SARS-CoV）-N gene recombinant replication-defective adenoviral vector, rAd-N, was generated and immunized BALB/c mice in a pcDNA3.1-N prime-rAd-N boost regimen. After humoral and cellular immune response detection, different levels of SARS-CoV N protein specific antibodies and interferon-γ （IFN-γ） secretion are shown compared to controls. The humoral immune response was induced more effectively by the DNA priming and recombinant adenovirus boosting regimen. There is a significant difference between heterogeneous and homologous vaccinations. The heterogeneous combinations were all higher than those of the homologous combinations in the induction of anti-N antibody response. Among the three heterogeneous combinations, pcDNA3.1-N/pcDNA3.1-N/pcDNA3.1-N/rAd-N induced the strongest antibody response. In the induction of IFN-γ production, the homologous combination of rAd-N/rAd-N/rAd-N/rAd-N was significantly stronger than that of pcDNA3.1-N/pcDNA3.1-N/pcDNA3.1-N/pcDNA3.1-N, but was relatively weaker than the heterogeneous combination of pcDAN3.1-N/pcDAN3.1-N/pcDAN3.1-N/rAd-N. This combination was a most efficient immunization regimen in induction of SARS-CoV-N-specific （IFN-γ） secretion just as the antibody response. These results suggest that DNA immunization followed by recombinant adenovirns boosting could be used as a potential SARS-CoV vaccine.展开更多
基金Acknowledgments We thank Dr Lena Claesson-Welsh （Uppsala University）, and PIs of Model Animal Research Center （MARC, Nanjing University） for the helpful discussion about the work, and Yanlan Cao, Wenting Shi and all the staff in the MARC Animal facility of Nanjing University for excellent technical assistance. This work wasfinancially supported by grants from the National Natural Science Foundation of China （30771069, 30671038, and 30930028）, the Ministry of Science and Technology of China （2006CB943500）, and the Ministry of Education of China （NCET： Program for New Century Excellent Talents in University）.
文摘Although VEGFR-3 deficiency disrupts blood vascular development during early embryogenesis, the underlying mechanism was not clear. To characterize its function in angiogenesis and lymphangiogenesis, we employed two genetically modified mouse models in this study, targeting the coding region for the ligand-binding domain （Vegfr△LBD） or the tyrosine kinase domain with an inactivation point mutation （Vegfr3^TKmat）. We show that lymphatic growth was disrupted in Vegfr3△LBD/△LBD and Vegfr3^TKmut3^TKmat mice, but blood vessels developed normally in both embryo and yolk sac. Interestingly, in Vegfr3△LBD/△LBD but not Vegfr3^TKmut3^TKmat mice, lymph sac was present but there was lack of iym- phangiogenic sprouting. We further demonstrate that both the wild-type and mutant forms of VEGFR-3 could form heterodimers with VEGFR-2, and decreased the level of phospho-VEGFR-2 and the downstream phospho-Erk1/2 in endothelial cells when they were treated with VEGF-A. These findings indicate that signaling mediated via VEGFR-3 activation by its cognate ligands （VEGF-C/-D） is not required for angiogenesis, and that VEGFR-3 may play a role in this process by modulating VEGFR-2-mediated signals.
文摘Interest in ion channels as drug targets for contraception has grown with the realization that certain ion channel subunits are located exclusively in sperm. Selective knockdown of ion channel subunits can lead to infertility without ill effects, and selective inhibitors and/ or openers of these ion channels could interfere with sperm function. In this study, in vivo electmporation （EP） and rete testis microinjection-mediated plasmid DNA were adopted to silence CatSper2 expression, which is essential in sperm hyperactivation. The results showed that high transfection efficiency and expression were achieved by plasmid DNA that was directly injected into the rete testis. As a result of the expression of CatSper2 being blocked, the treatment group showed significantly lower （P〈0.05） hyperactivation rate, fertilization rate in vitro, migration motility in viscoelastic solution and intracellular Ca2＋ peak. The low hyperactivation and fertilization rates lasted for 60 days. Meanwhile, analysis of the sperm survival rate and testis histology indicated that in vivo EP had no significant effect on the function of the testis, spermatogenesis or sperm activity. The present study demonstrated that it was feasible to achieve male contraception by silencing the expression of CatSper2, the key protein involved in sperm hvoeractivation.
文摘In order to investigate immunogenicity in the induction of humoral and cellular immune responses, severe acute respiratory syndrome associated coronavirus （SARS-CoV）-N gene recombinant replication-defective adenoviral vector, rAd-N, was generated and immunized BALB/c mice in a pcDNA3.1-N prime-rAd-N boost regimen. After humoral and cellular immune response detection, different levels of SARS-CoV N protein specific antibodies and interferon-γ （IFN-γ） secretion are shown compared to controls. The humoral immune response was induced more effectively by the DNA priming and recombinant adenovirus boosting regimen. There is a significant difference between heterogeneous and homologous vaccinations. The heterogeneous combinations were all higher than those of the homologous combinations in the induction of anti-N antibody response. Among the three heterogeneous combinations, pcDNA3.1-N/pcDNA3.1-N/pcDNA3.1-N/rAd-N induced the strongest antibody response. In the induction of IFN-γ production, the homologous combination of rAd-N/rAd-N/rAd-N/rAd-N was significantly stronger than that of pcDNA3.1-N/pcDNA3.1-N/pcDNA3.1-N/pcDNA3.1-N, but was relatively weaker than the heterogeneous combination of pcDAN3.1-N/pcDAN3.1-N/pcDAN3.1-N/rAd-N. This combination was a most efficient immunization regimen in induction of SARS-CoV-N-specific （IFN-γ） secretion just as the antibody response. These results suggest that DNA immunization followed by recombinant adenovirns boosting could be used as a potential SARS-CoV vaccine.
