Rho GTPases are molecular switches that act as key regulators of a many cellular processes, including cell movement, morphogenesis, host defense, cell division and gene expression. Rho GTPases are found in all eukaryo...Rho GTPases are molecular switches that act as key regulators of a many cellular processes, including cell movement, morphogenesis, host defense, cell division and gene expression. Rho GTPases are found in all eukaryotic kingdoms. Plants lack clear homologs to conventional Rho GTPases found in yeast and animals; instead, they have over time developed a unique subfamily, ROPs, also known as RAC. The origin of ROP-like proteins appears to precede the appearance of land plants. This review aims to discuss the evolution of ROP/RAC and to compare plant ROP and animal Rho GTPases, focusing on similarities and differences in regulation of the GTPases and their downstream effectors.展开更多
Via the use of Mimedisc~? as a scaffold, the normal human dermal fibroblasts were first seeding into the scaffold to form a dermal equivalent after three weeks, and then seeding normal human epidermal keratinocytes on...Via the use of Mimedisc~? as a scaffold, the normal human dermal fibroblasts were first seeding into the scaffold to form a dermal equivalent after three weeks, and then seeding normal human epidermal keratinocytes on it, followed by immersion and air-liquid interphase culture stage, to finally form a 3 D sponge matrix skin model which has a very similar structure of normal human skin(NHS). The results of Masson staining, and immunohistochemistry(IHC), immunofluorescence(IF) staininccg show that this skin model has a very similar structure and key protein expression of NHS. Meanwhile, this model was used as a tool to investigate the effect of Himalaya cedar extract on Dermal-Epidermal Junction(DEJ) in vitro. Results show that the Himalayan cedar extract can significantly increase the thickness of the epidermis, thus increase the barrier capacity of the skin to resist external environment. Further, this Himalaya cedar extract can promote the expressions of Laminin 5 and Collagen VII of DEJ. The expressions of the Laminin 5 and Collagen VII increased 20% and 47% respectively.So the Himalaya cedar extract displays the potential to be applied in development of anti-aging cosmetics.展开更多
In this study, a gemini-like cationic lipid （CLD） was used as the carrier to study the complexation features of CLD/ siRNA nanoplexes （CLD/siRNA NPs）. Three types of CLD/siRNA nanoplexes （named as AT NPs, HT NPs ...In this study, a gemini-like cationic lipid （CLD） was used as the carrier to study the complexation features of CLD/ siRNA nanoplexes （CLD/siRNA NPs）. Three types of CLD/siRNA nanoplexes （named as AT NPs, HT NPs and MT NPs） were prepared by different processes： AT method （mixing siRNA solution with preformed CLD nanoparticles）, HT method （hydrating a CLD thin film with siRNA solution）, and MT method （dropping an ethanolic solution of CLD into siRNA solution under sonication）. The particle size, zeta potential, morphology, siRNA protection, cytotoxicity, cellular uptake, and targeted mRNA downregulation were studied. At the optimal N/P ratio of 10, the sizes of the three CLD/siRNA NPs were MT NPs （（222.3±19.1） nm）〉 HT NPs （（105.7±1.31） nm）〉AT NPs （（91.8±1.75） nm）. Different nanostructures were formed despite the fact that they were composed of the same components. Furthermore, the TEM images indicated that different morphologies were found in the three NPs, indicating that the nanoplexes were assembled by different mechanisms. Among the three NPs, the cell uptake capacity were as follows： AT NPs〉MT NPs〉HT NPs, whereas the silencing levels on epidermal growth factor receptor （EGFR） in HeLa cells were MT NPs〉AT NPs〉HT NPs. Based on the above results, we hypothesized that the different preparation processes resulted in nanostructures with varying biological effects. Therefore, we believe that structural optimization of siRNA nanoplexes is essential in achieving better siRNA encapsulation, protection, and gene silencing efficiency.展开更多
基金This work was supported by the Bioteclmology and Functional genomics(FUGE)programs of the Norwegian Research Council through grants NFR 159959,164583 and 151991(T B,P W and A M B)by grants from the National Science Foundation,the Department of Energy and the US Department of Agriculture(Z Y).
文摘Rho GTPases are molecular switches that act as key regulators of a many cellular processes, including cell movement, morphogenesis, host defense, cell division and gene expression. Rho GTPases are found in all eukaryotic kingdoms. Plants lack clear homologs to conventional Rho GTPases found in yeast and animals; instead, they have over time developed a unique subfamily, ROPs, also known as RAC. The origin of ROP-like proteins appears to precede the appearance of land plants. This review aims to discuss the evolution of ROP/RAC and to compare plant ROP and animal Rho GTPases, focusing on similarities and differences in regulation of the GTPases and their downstream effectors.
文摘Via the use of Mimedisc~? as a scaffold, the normal human dermal fibroblasts were first seeding into the scaffold to form a dermal equivalent after three weeks, and then seeding normal human epidermal keratinocytes on it, followed by immersion and air-liquid interphase culture stage, to finally form a 3 D sponge matrix skin model which has a very similar structure of normal human skin(NHS). The results of Masson staining, and immunohistochemistry(IHC), immunofluorescence(IF) staininccg show that this skin model has a very similar structure and key protein expression of NHS. Meanwhile, this model was used as a tool to investigate the effect of Himalaya cedar extract on Dermal-Epidermal Junction(DEJ) in vitro. Results show that the Himalayan cedar extract can significantly increase the thickness of the epidermis, thus increase the barrier capacity of the skin to resist external environment. Further, this Himalaya cedar extract can promote the expressions of Laminin 5 and Collagen VII of DEJ. The expressions of the Laminin 5 and Collagen VII increased 20% and 47% respectively.So the Himalaya cedar extract displays the potential to be applied in development of anti-aging cosmetics.
基金National Basic Research Program of China(973 program,Grant No.2013CB932501)the National Natural Science Foundation of China(Grant No.81273455,81473158 and 81573374)Programs of Ministry of Education of China(Grant No.NCET-11-0014 and BMU20110263)
文摘In this study, a gemini-like cationic lipid （CLD） was used as the carrier to study the complexation features of CLD/ siRNA nanoplexes （CLD/siRNA NPs）. Three types of CLD/siRNA nanoplexes （named as AT NPs, HT NPs and MT NPs） were prepared by different processes： AT method （mixing siRNA solution with preformed CLD nanoparticles）, HT method （hydrating a CLD thin film with siRNA solution）, and MT method （dropping an ethanolic solution of CLD into siRNA solution under sonication）. The particle size, zeta potential, morphology, siRNA protection, cytotoxicity, cellular uptake, and targeted mRNA downregulation were studied. At the optimal N/P ratio of 10, the sizes of the three CLD/siRNA NPs were MT NPs （（222.3±19.1） nm）〉 HT NPs （（105.7±1.31） nm）〉AT NPs （（91.8±1.75） nm）. Different nanostructures were formed despite the fact that they were composed of the same components. Furthermore, the TEM images indicated that different morphologies were found in the three NPs, indicating that the nanoplexes were assembled by different mechanisms. Among the three NPs, the cell uptake capacity were as follows： AT NPs〉MT NPs〉HT NPs, whereas the silencing levels on epidermal growth factor receptor （EGFR） in HeLa cells were MT NPs〉AT NPs〉HT NPs. Based on the above results, we hypothesized that the different preparation processes resulted in nanostructures with varying biological effects. Therefore, we believe that structural optimization of siRNA nanoplexes is essential in achieving better siRNA encapsulation, protection, and gene silencing efficiency.
