Cellular senescence is an irreversible form of cell cycle arrest that provides a barrier to neoplastic transformation. The integrity of the Rb （Retinoblastoma） pathway is necessary for the formation of the senescenc...Cellular senescence is an irreversible form of cell cycle arrest that provides a barrier to neoplastic transformation. The integrity of the Rb （Retinoblastoma） pathway is necessary for the formation of the senescence-associated heterochromatin foci （SAHF） that offers a molecular basis for the stability of the senescent state. Surprisingly, although high mobility group A2 protein （HMGA2） can promote tumorigenesis and inhibit Rb function in tumor cells, high-level expression of HMGA2 is sufficient to induce SAHF formation in primary cells. It therefore becomes significant to determine whether Rb protein is necessary in HMGA2-induced SAHF formation. In this study, we established the cellular senescence and SAHF assembly W138 cell model by ectopic expression of HMGA2, in which typical senescent markers were seen, including notable upregulation of p53, p21 and p16, and elevated SA-[3-galactosidase staining together with downregulation of E2F target genes. We then showed that the Rb pathway inhibitor E7 protein was able to partly abolish the ability of SAHF formation alter HMGA2 expression in W138 cells, indicating that Rb is a crucial factor for HMGA2-induced SAHF formation. However. Rb depletion did not completely rescue the cell growth arrest induced by HMGA2, suggesting that Rb is not an exclusive pathway for HMGA2-induced senescence in W138 cells.展开更多
It is of great significance to construct organic circularly polarized luminescence systems(CPL) with large luminescence dissymmetry factors(g_(lum)) for practical applications. Here we report organic CPL systems const...It is of great significance to construct organic circularly polarized luminescence systems(CPL) with large luminescence dissymmetry factors(g_(lum)) for practical applications. Here we report organic CPL systems constructed by merging triplet-triplet annihilation upconversion chromophores in cellulose matrices. The chirality of the matrix is transferred to the achiral chromophores of photon upconversion and then the multistep energy transfer processes of upconversion amplify g_(lum). The g_(lum)value of upconversion CPL in the left-handed ethyl cellulose and the right-handed(acetyl) ethyl cellulose are up to +0.1 and -0.15, respectively. The study provides a straightforward approach for constructing solid organic upconversion CPL materials with large g_(lum), which may expand the application potentials of organic chiroptical materials.展开更多
Objective：To explore the antibacterial effect of Chinese crude drugs against clinical strains of Ureaplasma urealyticum（UU）, including eight pure herbs and three compound herbs, and determine their minimal inhibito...Objective：To explore the antibacterial effect of Chinese crude drugs against clinical strains of Ureaplasma urealyticum（UU）, including eight pure herbs and three compound herbs, and determine their minimal inhibitory concentrations（MICs）. Methods：Isolates were collected from clinical patients with UU infection, and cultured in UU broth. In order to test the different effects on clinical strains of UU, the assays were performed by microdilution inhibition tests, and MICs of the herbs against the clinical strains of UU were calculated. Results：The MICs of eight pure herbs against clinical strains of UU were as follows： Galla Chinensis：0.313-1.25 g/L; Fructus Forsythiae： 1.25-5.00 g/L; Cortex Phellodendri： 1.25-5.00 g/L; Radix Paeoniae Rubra： 1.25-2.50 g/L; Semen Plantaginis：2.50-10.00 g/L; Herba Lysimachiae： 5.00-20.00 g/L; Rhizoma Coptidis： 5.00-20.00g/L, Herba Houttuyniae： 10.00-20.00 g/L. The MICs of compound herbs were： Liuheji： 0.625-2.50 g/L; Bazhengsan： 5.00-20.00 g/L; Wulinsan：2.50-20.0 g/L.Conclusion：Galla Chinensis, Fructus Forsythiae, Cortex Phellodendrim, Radix Paeoniae Rubra, and Semen Plantaginis, exerted the stronger antibacterial effect against clinical strains of UU, whereas Herba Lysimachiae, Rhizoma Coptidis and Herba Houttuyniae, had relatively weaker activity against UU. Compound herbs, Bazhengsan and Wulinsan, and particularly Liuheji, also had antibacterial effects against UU. Further studies of the effects and mechanisms of action of Chinese crude drugs against UU infections are worthwhile.展开更多
基金supported by the grants from the National Natural Science Foundation of China(Nos.31100998 and 31050015)the Fundamental Research Funds for the Central Universities(No.11SSXT132)
文摘Cellular senescence is an irreversible form of cell cycle arrest that provides a barrier to neoplastic transformation. The integrity of the Rb （Retinoblastoma） pathway is necessary for the formation of the senescence-associated heterochromatin foci （SAHF） that offers a molecular basis for the stability of the senescent state. Surprisingly, although high mobility group A2 protein （HMGA2） can promote tumorigenesis and inhibit Rb function in tumor cells, high-level expression of HMGA2 is sufficient to induce SAHF formation in primary cells. It therefore becomes significant to determine whether Rb protein is necessary in HMGA2-induced SAHF formation. In this study, we established the cellular senescence and SAHF assembly W138 cell model by ectopic expression of HMGA2, in which typical senescent markers were seen, including notable upregulation of p53, p21 and p16, and elevated SA-[3-galactosidase staining together with downregulation of E2F target genes. We then showed that the Rb pathway inhibitor E7 protein was able to partly abolish the ability of SAHF formation alter HMGA2 expression in W138 cells, indicating that Rb is a crucial factor for HMGA2-induced SAHF formation. However. Rb depletion did not completely rescue the cell growth arrest induced by HMGA2, suggesting that Rb is not an exclusive pathway for HMGA2-induced senescence in W138 cells.
基金financial support from the National Natural Science Foundation of China(Nos.21673264,21573266,21672226 and 22090012)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Nos.2017032 and 2020035)。
文摘It is of great significance to construct organic circularly polarized luminescence systems(CPL) with large luminescence dissymmetry factors(g_(lum)) for practical applications. Here we report organic CPL systems constructed by merging triplet-triplet annihilation upconversion chromophores in cellulose matrices. The chirality of the matrix is transferred to the achiral chromophores of photon upconversion and then the multistep energy transfer processes of upconversion amplify g_(lum). The g_(lum)value of upconversion CPL in the left-handed ethyl cellulose and the right-handed(acetyl) ethyl cellulose are up to +0.1 and -0.15, respectively. The study provides a straightforward approach for constructing solid organic upconversion CPL materials with large g_(lum), which may expand the application potentials of organic chiroptical materials.
文摘Objective：To explore the antibacterial effect of Chinese crude drugs against clinical strains of Ureaplasma urealyticum（UU）, including eight pure herbs and three compound herbs, and determine their minimal inhibitory concentrations（MICs）. Methods：Isolates were collected from clinical patients with UU infection, and cultured in UU broth. In order to test the different effects on clinical strains of UU, the assays were performed by microdilution inhibition tests, and MICs of the herbs against the clinical strains of UU were calculated. Results：The MICs of eight pure herbs against clinical strains of UU were as follows： Galla Chinensis：0.313-1.25 g/L; Fructus Forsythiae： 1.25-5.00 g/L; Cortex Phellodendri： 1.25-5.00 g/L; Radix Paeoniae Rubra： 1.25-2.50 g/L; Semen Plantaginis：2.50-10.00 g/L; Herba Lysimachiae： 5.00-20.00 g/L; Rhizoma Coptidis： 5.00-20.00g/L, Herba Houttuyniae： 10.00-20.00 g/L. The MICs of compound herbs were： Liuheji： 0.625-2.50 g/L; Bazhengsan： 5.00-20.00 g/L; Wulinsan：2.50-20.0 g/L.Conclusion：Galla Chinensis, Fructus Forsythiae, Cortex Phellodendrim, Radix Paeoniae Rubra, and Semen Plantaginis, exerted the stronger antibacterial effect against clinical strains of UU, whereas Herba Lysimachiae, Rhizoma Coptidis and Herba Houttuyniae, had relatively weaker activity against UU. Compound herbs, Bazhengsan and Wulinsan, and particularly Liuheji, also had antibacterial effects against UU. Further studies of the effects and mechanisms of action of Chinese crude drugs against UU infections are worthwhile.
