A ratiometric fluorescent sensor（Hoe-NI） was developed by connecting a nucleus targeted Hoechst unit to a naphthalimide dye via ＂click chemistry＂. The sensor achieves high specific nucleus labeling with wash-free ...A ratiometric fluorescent sensor（Hoe-NI） was developed by connecting a nucleus targeted Hoechst unit to a naphthalimide dye via ＂click chemistry＂. The sensor achieves high specific nucleus labeling with wash-free staining method in various kinds of living cells. The fluorescence ratio of the two emission bands（450 nm for Hoechst and 505 nm for naphthalimide） is changed sensitively to the variation of DNA concentrations, which provides the quantitative information in the processes of DNA damage induced by hydroxyl radicals and antitumor drug. Therefore, Hoe-NI is a recommendable sensor for the monitoring of nuclear DNA damage that reveals the health status of cells.展开更多
To explore the neural mechanisms mediating agingrelated visual function declines, we compared the expressions of brain-derived neurotrophic factor（BDNF） and its high affinity receptor-tyrosine kinase B（Trk B） betw...To explore the neural mechanisms mediating agingrelated visual function declines, we compared the expressions of brain-derived neurotrophic factor（BDNF） and its high affinity receptor-tyrosine kinase B（Trk B） between young and old adult cats. Nissl staining was used to display neurons in each layer of the lateral geniculate nucleus（LGN）. The BDNF- and Trk B receptor-immunoreactive neurons were labeled immunohistochemically, observed under optical microscope and photographed. Their neuronal density and immunoreactive intensity were measured. Results showed that the mean density of the Nissl stained neurons in each LGN layer were comparable between old and young adult cats, and their BDNF and Trk B proteins were widely expressed in all LGN layers. However, compared with young adult cats, both the density and optical absorbance intensity of BDNF- and Trk B-immunoreactive cells in each LGN layer in old cats were significantly decreased. These findings indicate that the decreased expressions of BDNF and Trk B proteins in the LGN may be an important factor inducing the compromised inhibition in the central visual nucleus and the functional visual decline in senescent individuals.展开更多
Substantial evidence has suggested that deep brain stimulation of the cuneiform nucleus has become a remarkable treatment option for intractable pain,but the possible mechanism is poorly understood. Using a melanocort...Substantial evidence has suggested that deep brain stimulation of the cuneiform nucleus has become a remarkable treatment option for intractable pain,but the possible mechanism is poorly understood. Using a melanocortin-4 receptor（MC4R）-green fluorescent protein（GFP） reporter knockin mouse,we showed that a large number of MC4R-GFP-positive neurons were expressed in the cuneiform nucleus. Immunofluorescence revealed that approximately 40%–50% of MC4R-GFP-positive neurons expressed mu opioid receptors,indicating that they were opioidergic signaling. Our findings support the hypothesis that MC4 R expression in the cuneiform nucleus is involved in the modulation of opioidergic signaling.展开更多
Genetic lineage tracing has been widely employed to investigate cell lineages and fate.However,conventional reporting systems often label the entire cytoplasm,making it challenging to discern cell boundaries.Additiona...Genetic lineage tracing has been widely employed to investigate cell lineages and fate.However,conventional reporting systems often label the entire cytoplasm,making it challenging to discern cell boundaries.Additionally,single Cre-lox P recombination systems have limitations in tracing specific cell populations.This study proposes three reporting systems utilizing Cre,Dre,and Dre+Cre mediated recombination.These systems incorporate td Tomato expression on the cell membrane and Phi YFP expression within the nucleus,allowing for clear observation of the nucleus and membrane.The efficacy of these systems is successfully demonstrated by labeling cardiomyocytes and hepatocytes.The potential for dynamic visualization of the cell membrane is showcased using intravital imaging microscopy or threedimensional imaging.Furthermore,by combining this dual recombinase system with the Pro Tracer system,hepatocyte proliferation is traced with enhanced precision.This reporting system holds significant importance for advancing the understanding of cell fate studies in development,homeostasis,and diseases.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 21376038, 21421005 and 21576040)National Basic Research Program of China (No. 2013CB733702)
文摘A ratiometric fluorescent sensor（Hoe-NI） was developed by connecting a nucleus targeted Hoechst unit to a naphthalimide dye via ＂click chemistry＂. The sensor achieves high specific nucleus labeling with wash-free staining method in various kinds of living cells. The fluorescence ratio of the two emission bands（450 nm for Hoechst and 505 nm for naphthalimide） is changed sensitively to the variation of DNA concentrations, which provides the quantitative information in the processes of DNA damage induced by hydroxyl radicals and antitumor drug. Therefore, Hoe-NI is a recommendable sensor for the monitoring of nuclear DNA damage that reveals the health status of cells.
基金This study was supported by the National Natural Science Foundation of China （31171082） the Key Project of Natural Science Research of the Education Bureau of Anhui Province （KJ2014A284） the Foundation of Key Laboratories of Anhui Province and Key Laboratories of Universities of Anhui Province
文摘To explore the neural mechanisms mediating agingrelated visual function declines, we compared the expressions of brain-derived neurotrophic factor（BDNF） and its high affinity receptor-tyrosine kinase B（Trk B） between young and old adult cats. Nissl staining was used to display neurons in each layer of the lateral geniculate nucleus（LGN）. The BDNF- and Trk B receptor-immunoreactive neurons were labeled immunohistochemically, observed under optical microscope and photographed. Their neuronal density and immunoreactive intensity were measured. Results showed that the mean density of the Nissl stained neurons in each LGN layer were comparable between old and young adult cats, and their BDNF and Trk B proteins were widely expressed in all LGN layers. However, compared with young adult cats, both the density and optical absorbance intensity of BDNF- and Trk B-immunoreactive cells in each LGN layer in old cats were significantly decreased. These findings indicate that the decreased expressions of BDNF and Trk B proteins in the LGN may be an important factor inducing the compromised inhibition in the central visual nucleus and the functional visual decline in senescent individuals.
基金supported by a grant from Health and Family Planning Commission of Hubei Province(No.WJ2015MB008)
文摘Substantial evidence has suggested that deep brain stimulation of the cuneiform nucleus has become a remarkable treatment option for intractable pain,but the possible mechanism is poorly understood. Using a melanocortin-4 receptor（MC4R）-green fluorescent protein（GFP） reporter knockin mouse,we showed that a large number of MC4R-GFP-positive neurons were expressed in the cuneiform nucleus. Immunofluorescence revealed that approximately 40%–50% of MC4R-GFP-positive neurons expressed mu opioid receptors,indicating that they were opioidergic signaling. Our findings support the hypothesis that MC4 R expression in the cuneiform nucleus is involved in the modulation of opioidergic signaling.
基金supported by the National Key Research&Development Program of China(2021YFA0805100,2023YFA1800700,2019YFA0110403,2019YFA0802000)the National Science Foundation of China(82088101,32370885,92368103,32370897)the Westlake Education Foundation,and the Benyuan Charity Fund,Research Funds of Hangzhou Institute for Advanced Study(2022ZZ01015 and B04006C01600515)。
文摘Genetic lineage tracing has been widely employed to investigate cell lineages and fate.However,conventional reporting systems often label the entire cytoplasm,making it challenging to discern cell boundaries.Additionally,single Cre-lox P recombination systems have limitations in tracing specific cell populations.This study proposes three reporting systems utilizing Cre,Dre,and Dre+Cre mediated recombination.These systems incorporate td Tomato expression on the cell membrane and Phi YFP expression within the nucleus,allowing for clear observation of the nucleus and membrane.The efficacy of these systems is successfully demonstrated by labeling cardiomyocytes and hepatocytes.The potential for dynamic visualization of the cell membrane is showcased using intravital imaging microscopy or threedimensional imaging.Furthermore,by combining this dual recombinase system with the Pro Tracer system,hepatocyte proliferation is traced with enhanced precision.This reporting system holds significant importance for advancing the understanding of cell fate studies in development,homeostasis,and diseases.
