Vision depends on accurate signal conduction from the retina to the brain through the optic nerve,an important part of the central nervous system that consists of bundles of axons originating from retinal ganglion cel...Vision depends on accurate signal conduction from the retina to the brain through the optic nerve,an important part of the central nervous system that consists of bundles of axons originating from retinal ganglion cells.The mammalian optic nerve,an important part of the central nervous system,cannot regenerate once it is injured,leading to permanent vision loss.To date,there is no clinical treatment that can regenerate the optic nerve and restore vision.Our previous study found that the mobile zinc(Zn^(2+))level increased rapidly after optic nerve injury in the retina,specifically in the vesicles of the inner plexiform layer.Furthermore,chelating Zn^(2+)significantly promoted axonal regeneration with a long-term effect.In this study,we conditionally knocked out zinc transporter 3(ZnT3)in amacrine cells or retinal ganglion cells to construct two transgenic mouse lines(VGAT^(Cre)ZnT3^(fl/fl)and VGLUT2^(Cre)ZnT3^(fl/fl),respectively).We obtained direct evidence that the rapidly increased mobile Zn^(2+)in response to injury was from amacrine cells.We also found that selective deletion of ZnT3 in amacrine cells promoted retinal ganglion cell survival and axonal regeneration after optic nerve crush injury,improved retinal ganglion cell function,and promoted vision recovery.Sequencing analysis of reginal ganglion cells revealed that inhibiting the release of presynaptic Zn^(2+)affected the transcription of key genes related to the survival of retinal ganglion cells in postsynaptic neurons,regulated the synaptic connection between amacrine cells and retinal ganglion cells,and affected the fate of retinal ganglion cells.These results suggest that amacrine cells release Zn^(2+)to trigger transcriptomic changes related to neuronal growth and survival in reginal ganglion cells,thereby influencing the synaptic plasticity of retinal networks.These results make the theory of zinc-dependent retinal ganglion cell death more accurate and complete and provide new insights into the complex interactions between retinal cell networks.展开更多
[Objective] This study aimed to perform the bioinformatics analysis of Zinc transporter （ZnT） from Baoding Alfalfa. [Method] Based on the amino acid sequence, the physical and chemical properties, hydrophilicity/hyd...[Objective] This study aimed to perform the bioinformatics analysis of Zinc transporter （ZnT） from Baoding Alfalfa. [Method] Based on the amino acid sequence, the physical and chemical properties, hydrophilicity/hydrophobicity, secondary structure of ZnT from Baoding alfalfa were predicted by a series of bioinformatics software. And the transmembrane domains were predicted by using different online tools. [Result] ZnT is a hydrophobic protein containing 408 amino acids with the theoretical pl of 5.94, and it has 7 potential transmembrane hydrophobic regions. In the sec- ondary structure, co-helix （Hh） accounted for 48.04%, extended strand （Ee） for 9.56%, random coil （Cc） for 42.40%, which was accored with the characteristic of transmembrane protein. [Conclusion] mZnT is a member of CDF family, responsible for transporting Zn^2＋ out of the cell membrane to reduce the concentration and toxicity of Zn^2＋.展开更多
A study on the transport characteristics of zinc in lou soil with phosphate at different concentrations was carried out by the method of step input. The effects of phosphate and temperature on zinc transport were stud...A study on the transport characteristics of zinc in lou soil with phosphate at different concentrations was carried out by the method of step input. The effects of phosphate and temperature on zinc transport were studied through analysing the diffusion-dispersion coefficients (D) and the retardation factor (R) obtained by the program CXTFIT. The results showed that D decreased and R increased with increasing concentration of phosphate so that it was difficult for zinc to break through the soil column, and zinc stopped to break through the column at high temperature. One order equation, double constant equation and the Elovich equation were all suitable for the description of zinc dynamica. Effects of phosphate and temperature on zinc transport were further confirmed by the analysis on pseudo-thermodynamic parameters of zinc transport.展开更多
BACKGROUND： Developmental seizures are pathologically characterized by regenerative sprouting of hippocampal mossy fibers rich in Zn^2＋. Zn^2＋ metabolism in the mossy fiber pathway, and Zn^2＋ accumulation in presy...BACKGROUND： Developmental seizures are pathologically characterized by regenerative sprouting of hippocampal mossy fibers rich in Zn^2＋. Zn^2＋ metabolism in the mossy fiber pathway, and Zn^2＋ accumulation in presynaptic membrane vesicles, are dependent on zinc transporter 1 （ZnT1） and glutamate receptor subunit 2 （GluR2）. OBJECTIVE： To investigate the effects of long-term recurrent neonatal seizure, in the presence and absence of physical exercise, on the developmental expression of hippocampal zinc transporter 1 （ZnT1） and GluR2, and on cognitive function in rats. DESIGN, TIME AND SETTING： Based on behavioral examination and molecular biological research, a randomized, controlled animal experiment was performed at the Department of Neurobiology, Medical College of Soochow University, between January 2007 and April 2008. MATERIALS： Twenty-one 6-day-old Sprague Dawley rats of either gender were employed in this study. ZnT1 mRNA in situ hybridization kit was provided by Tianjin Haoyang Biological Manufacture Co.,Ltd., China. Rabbit anti-GluR2 was purchased from Santa Cruz Biotech, Inc, USA. METHODS： Rats were randomly divided into a recurrent seizure group （n = 11） and a control group （n = 10）. In the recurrent seizure group, 30-minute seizure was induced by flurothyl gas inhalation for a total of 6 consecutive days. Rats from the control group underwent experimental procedures similar to the recurrent seizure group, with the exception of flurothyl gas inhalation. Thirty minutes of treadmill exercise was performed daily by all rats at postnatal days 51–56. MAIN OUTCOME MEASURES： At postnatal day 82, rat hippocampal tissue was harvested for analysis of hippocampal ZnT1 and GluR2 expression by in situ hybridization and immunohistochemistry, respectively. Rat learning and memory capabilities were examined using the Y-maze test. RESULTS： In the recurrent seizure group, the gray scale value of ZnT1 in situ hybridization positive neurons in the hippocampal CA3 region was significantly greater （P 〈 0.05）, while the gray scale value of GluR2 immunoreactive neurons in the hippocampal hilus and dentate gyrus was significantly lower （P 〈 0.05）, than in the control group. At postnatal days 29–35, numbers of trials to criteria for successful learning were greater in the recurrent seizure group than in the control group （P 〈 0.05）; at postnatal days 61–67, the numbers of trials to criteria for successful learning were similar between the two groups （P 〉 0.05）. At postnatal days 29–35 and 61–67, there was no significant difference in memory capability between the recurrent seizure and control groups （P 〉 0.05）. CONCLUSION： Physical exercise likely improves the learning deficits caused by recurrent neonatal seizure in rats during brain development by modulating ZnT1 and GluR2 expression.展开更多
BACKGROUND： Developmental seizures, which are pathologically characterized by regenerative sprouting of hippocampal mossy fibers, cause long-term damaging effects to synaptic plasticity. Zn^2＋ metabolism has been sh...BACKGROUND： Developmental seizures, which are pathologically characterized by regenerative sprouting of hippocampal mossy fibers, cause long-term damaging effects to synaptic plasticity. Zn^2＋ metabolism has been shown to contribute to the regenerative sprouting of hippocampal mossy fibers Furthermore, zinc transporter-3 （ZnT3） is responsible for Zn^2＋ transport in the hippocampal mossy fiber pathway. OBJECTIVE： To investigate the effects of long-term recurrent neonatal seizures on learning, memory formation and hippocampal ZnT3 expression in rats. DESIGN, TIME AND SETTING： Based on molecular biological research and behavioral examination a randomized, controlled, animal experiment was performed at the Laboratory Animal Center, Peking University Health Science Center, between October 2004 and July 2005. MATERIALS： Flurothyl was purchased from Aldrich Chemical Co., USA. ZnT3 mRNA in situ hybridization kits were provided by Tianjin Haoyang Biological Manufacture Co., Ltd., China. Morris water maze was produced by Shanghai Jiliang Science and Technology Co., Ltd., China. METHODS： Sixty, 6-day old, Wistar rats were randomly divided into three groups： single seizure （n = 21）, recurrent seizure （n = 21, one seizure daily for 6 consecutive days）, and control （n = 18）. Seizures were induced by flurothyl gas inhalation, in the single seizure and recurrent seizure groups. MAIN OUTCOME MEASURES： At postnatal days 12, 46 and 90, rat hippocampal ZnT3 mRNA expression was detected by RT-PCR; at postnatal days 46 and 90, ZnT3 mRNA expression was determined by in situ hybridization; and at postnatal days 41-46 and 85 90, rat spatial learning and memory formation were examined by the Morris water maze test. RESULTS： RT-PCR results revealed that at postnatal day 12, ZnT3 expression was significantly greater in the recurrent seizure group than in the control and single seizure groups, and at day 46, it was also significantly greater in the recurrent seizure group compared with the control group （P 〈 0.05）. In situ hybridization results showed that at postnatal day 46, the recurrent seizure group exhibited increased hippocampal ZnT3 expression over the control and single seizure groups （P〈0.05）. Morris water maze test results displayed that, in the first place navigation test at postnatal day 44, and the second test at days 87-88, the recurrent seizure group exhibited significantly higher value of average escape latency compared with the control group （P 〈 0.05）. In the two spatial probe tests, the search strategies were significantly inferior in the recurrent seizure group than in the control and single seizure groups （P 〈 0.05）. CONCLUSION： Neonatal concurrent seizures produce long-term damaging effects on hippocampal ZnT3 expression and cognitive function, while both of which have no parallel correlation.展开更多
We demonstrate that the electroluminescent performances of organic light-emitting diodes are significantly improved by employing a zinc phthalocyanine （ZnPc）-based composite hole transport layer （c-HTL）. The optim...We demonstrate that the electroluminescent performances of organic light-emitting diodes are significantly improved by employing a zinc phthalocyanine （ZnPc）-based composite hole transport layer （c-HTL）. The optimum ris-（8-hydroxyquinoline）aluminum （Alq3）-based organic light-emitting diode with a c-HTL exhibits a lower turn-on voltage of 2.8 V, a higher maximum current efficiency of 3.40 cd/A and a higher maximum power efficiency of 1.91 lm/W, which are superior to those of the conventional device （turn-on voltage of 3.8 V, maximum current efficiency of 2.60 cd/A, and maximum power efficiency of 1.21 lm/W）. We systematically studied the effects of different kinds of N’-diphenyl-N,N’-bis（1-naphthyl）（1,1’-biphenyl）-4,4’diamine （NPB）：ZnPc c-HTL. Meanwhile, we also investigate their mechanisms different from that in the case of using ZnPc as buffer layer. The specific analysis is based on the absorption spectra of the hole transporting material and current density–voltage characteristics of the corresponding hole-only devices.展开更多
Zinc(Zn) is an essential mineral element for plant growth and development. Zn deficiency in crops frequently occurs in many types of soils. It is therefore crucial to identify genetic resources linking Zn acquisition ...Zinc(Zn) is an essential mineral element for plant growth and development. Zn deficiency in crops frequently occurs in many types of soils. It is therefore crucial to identify genetic resources linking Zn acquisition traits and development of crops with improved Zn-use efficiency for sustainable crop production. In this study, we functionally identified a rice uncharacterized ABCG(ATP-binding cassette G-subfamily) gene encoding a PDR20(pleiotropic drug resistance 20) metal transporter for mediation of rice growth, seed development and Zn accumulation. OsPDR20 was localized to the plasma membrane, but it was not transcriptionally induced under Zn deficiency, rather was sufficiently up-regulated under high level of Zn stress. Yeast(Saccharomyces cerevisiae) transformed with OsPDR20 displayed a relatively lower Zn accumulation with attenuated cellular growth, suggesting that OsPDR20 had an activity for Zn transport. Knocking-down OsPDR20 by RNA interference(RNAi) compromised rice growth with shorter plant height and decreased biomass in rice plantlets grown under hydroponic media. Zn concentration in the roots of OsPDR20 knocked-down rice lines declined under Zn deficiency, while they remained unchanged compared with the wild type under normal Zn supply. A rice lifelong field trial demonstrated that OsPDR20 mutation impaired the capacity of seed development, with shortened panicle and seed length, compromised spikelet fertility, and reduced grain number per plant or grain weight per unit area. Interestingly, OsPDR20 mutation elevated the accumulation of Zn in husk and brown rice over the wild type. Overall, this study pointed out that OsPDR20 is fundamentally required for rice growth and seed development through Zn transport and homeostasis.展开更多
基金the National Key R&D Project of China,No.2020YFA0112701(to YZ)the National Natural Science Foundation of China,Nos.82171057(to YZ),81870657(to YL)+1 种基金Science and Technology Program of Guangzhou of China,No.202206080005(to YZ)the Natural Science Foundation of Guangdong Province of China,No.2022A1515012168(to YL)。
文摘Vision depends on accurate signal conduction from the retina to the brain through the optic nerve,an important part of the central nervous system that consists of bundles of axons originating from retinal ganglion cells.The mammalian optic nerve,an important part of the central nervous system,cannot regenerate once it is injured,leading to permanent vision loss.To date,there is no clinical treatment that can regenerate the optic nerve and restore vision.Our previous study found that the mobile zinc(Zn^(2+))level increased rapidly after optic nerve injury in the retina,specifically in the vesicles of the inner plexiform layer.Furthermore,chelating Zn^(2+)significantly promoted axonal regeneration with a long-term effect.In this study,we conditionally knocked out zinc transporter 3(ZnT3)in amacrine cells or retinal ganglion cells to construct two transgenic mouse lines(VGAT^(Cre)ZnT3^(fl/fl)and VGLUT2^(Cre)ZnT3^(fl/fl),respectively).We obtained direct evidence that the rapidly increased mobile Zn^(2+)in response to injury was from amacrine cells.We also found that selective deletion of ZnT3 in amacrine cells promoted retinal ganglion cell survival and axonal regeneration after optic nerve crush injury,improved retinal ganglion cell function,and promoted vision recovery.Sequencing analysis of reginal ganglion cells revealed that inhibiting the release of presynaptic Zn^(2+)affected the transcription of key genes related to the survival of retinal ganglion cells in postsynaptic neurons,regulated the synaptic connection between amacrine cells and retinal ganglion cells,and affected the fate of retinal ganglion cells.These results suggest that amacrine cells release Zn^(2+)to trigger transcriptomic changes related to neuronal growth and survival in reginal ganglion cells,thereby influencing the synaptic plasticity of retinal networks.These results make the theory of zinc-dependent retinal ganglion cell death more accurate and complete and provide new insights into the complex interactions between retinal cell networks.
基金Supported by the General Project of Qujing Normal University(2010MS007)~~
文摘[Objective] This study aimed to perform the bioinformatics analysis of Zinc transporter （ZnT） from Baoding Alfalfa. [Method] Based on the amino acid sequence, the physical and chemical properties, hydrophilicity/hydrophobicity, secondary structure of ZnT from Baoding alfalfa were predicted by a series of bioinformatics software. And the transmembrane domains were predicted by using different online tools. [Result] ZnT is a hydrophobic protein containing 408 amino acids with the theoretical pl of 5.94, and it has 7 potential transmembrane hydrophobic regions. In the sec- ondary structure, co-helix （Hh） accounted for 48.04%, extended strand （Ee） for 9.56%, random coil （Cc） for 42.40%, which was accored with the characteristic of transmembrane protein. [Conclusion] mZnT is a member of CDF family, responsible for transporting Zn^2＋ out of the cell membrane to reduce the concentration and toxicity of Zn^2＋.
文摘A study on the transport characteristics of zinc in lou soil with phosphate at different concentrations was carried out by the method of step input. The effects of phosphate and temperature on zinc transport were studied through analysing the diffusion-dispersion coefficients (D) and the retardation factor (R) obtained by the program CXTFIT. The results showed that D decreased and R increased with increasing concentration of phosphate so that it was difficult for zinc to break through the soil column, and zinc stopped to break through the column at high temperature. One order equation, double constant equation and the Elovich equation were all suitable for the description of zinc dynamica. Effects of phosphate and temperature on zinc transport were further confirmed by the analysis on pseudo-thermodynamic parameters of zinc transport.
基金the National Natural Science Foundation of China, No. 30470555, 30571909, 30870808the Natural Science Foundation of Jiangsu Province, No. BK2007509Natural Science Foundation for Colleges and Universities in Jiangsu Province, No. 07KJB320103
文摘BACKGROUND： Developmental seizures are pathologically characterized by regenerative sprouting of hippocampal mossy fibers rich in Zn^2＋. Zn^2＋ metabolism in the mossy fiber pathway, and Zn^2＋ accumulation in presynaptic membrane vesicles, are dependent on zinc transporter 1 （ZnT1） and glutamate receptor subunit 2 （GluR2）. OBJECTIVE： To investigate the effects of long-term recurrent neonatal seizure, in the presence and absence of physical exercise, on the developmental expression of hippocampal zinc transporter 1 （ZnT1） and GluR2, and on cognitive function in rats. DESIGN, TIME AND SETTING： Based on behavioral examination and molecular biological research, a randomized, controlled animal experiment was performed at the Department of Neurobiology, Medical College of Soochow University, between January 2007 and April 2008. MATERIALS： Twenty-one 6-day-old Sprague Dawley rats of either gender were employed in this study. ZnT1 mRNA in situ hybridization kit was provided by Tianjin Haoyang Biological Manufacture Co.,Ltd., China. Rabbit anti-GluR2 was purchased from Santa Cruz Biotech, Inc, USA. METHODS： Rats were randomly divided into a recurrent seizure group （n = 11） and a control group （n = 10）. In the recurrent seizure group, 30-minute seizure was induced by flurothyl gas inhalation for a total of 6 consecutive days. Rats from the control group underwent experimental procedures similar to the recurrent seizure group, with the exception of flurothyl gas inhalation. Thirty minutes of treadmill exercise was performed daily by all rats at postnatal days 51–56. MAIN OUTCOME MEASURES： At postnatal day 82, rat hippocampal tissue was harvested for analysis of hippocampal ZnT1 and GluR2 expression by in situ hybridization and immunohistochemistry, respectively. Rat learning and memory capabilities were examined using the Y-maze test. RESULTS： In the recurrent seizure group, the gray scale value of ZnT1 in situ hybridization positive neurons in the hippocampal CA3 region was significantly greater （P 〈 0.05）, while the gray scale value of GluR2 immunoreactive neurons in the hippocampal hilus and dentate gyrus was significantly lower （P 〈 0.05）, than in the control group. At postnatal days 29–35, numbers of trials to criteria for successful learning were greater in the recurrent seizure group than in the control group （P 〈 0.05）; at postnatal days 61–67, the numbers of trials to criteria for successful learning were similar between the two groups （P 〉 0.05）. At postnatal days 29–35 and 61–67, there was no significant difference in memory capability between the recurrent seizure and control groups （P 〉 0.05）. CONCLUSION： Physical exercise likely improves the learning deficits caused by recurrent neonatal seizure in rats during brain development by modulating ZnT1 and GluR2 expression.
基金the National Natural Science Foundation of China,No.30470555, 30870808the Natural Science Foundation of Jiangsu Province of China, No.BK2007509the Natural Science Foundation for Higher Education Institutions in Jiangsu Province, No.07KJB320103
文摘BACKGROUND： Developmental seizures, which are pathologically characterized by regenerative sprouting of hippocampal mossy fibers, cause long-term damaging effects to synaptic plasticity. Zn^2＋ metabolism has been shown to contribute to the regenerative sprouting of hippocampal mossy fibers Furthermore, zinc transporter-3 （ZnT3） is responsible for Zn^2＋ transport in the hippocampal mossy fiber pathway. OBJECTIVE： To investigate the effects of long-term recurrent neonatal seizures on learning, memory formation and hippocampal ZnT3 expression in rats. DESIGN, TIME AND SETTING： Based on molecular biological research and behavioral examination a randomized, controlled, animal experiment was performed at the Laboratory Animal Center, Peking University Health Science Center, between October 2004 and July 2005. MATERIALS： Flurothyl was purchased from Aldrich Chemical Co., USA. ZnT3 mRNA in situ hybridization kits were provided by Tianjin Haoyang Biological Manufacture Co., Ltd., China. Morris water maze was produced by Shanghai Jiliang Science and Technology Co., Ltd., China. METHODS： Sixty, 6-day old, Wistar rats were randomly divided into three groups： single seizure （n = 21）, recurrent seizure （n = 21, one seizure daily for 6 consecutive days）, and control （n = 18）. Seizures were induced by flurothyl gas inhalation, in the single seizure and recurrent seizure groups. MAIN OUTCOME MEASURES： At postnatal days 12, 46 and 90, rat hippocampal ZnT3 mRNA expression was detected by RT-PCR; at postnatal days 46 and 90, ZnT3 mRNA expression was determined by in situ hybridization; and at postnatal days 41-46 and 85 90, rat spatial learning and memory formation were examined by the Morris water maze test. RESULTS： RT-PCR results revealed that at postnatal day 12, ZnT3 expression was significantly greater in the recurrent seizure group than in the control and single seizure groups, and at day 46, it was also significantly greater in the recurrent seizure group compared with the control group （P 〈 0.05）. In situ hybridization results showed that at postnatal day 46, the recurrent seizure group exhibited increased hippocampal ZnT3 expression over the control and single seizure groups （P〈0.05）. Morris water maze test results displayed that, in the first place navigation test at postnatal day 44, and the second test at days 87-88, the recurrent seizure group exhibited significantly higher value of average escape latency compared with the control group （P 〈 0.05）. In the two spatial probe tests, the search strategies were significantly inferior in the recurrent seizure group than in the control and single seizure groups （P 〈 0.05）. CONCLUSION： Neonatal concurrent seizures produce long-term damaging effects on hippocampal ZnT3 expression and cognitive function, while both of which have no parallel correlation.
基金Project supported by the National Key Basic Research and Development Program of China(Grant No.2010CB327701)the National Natural Science Foundation of China(Grant No.61275033)
文摘We demonstrate that the electroluminescent performances of organic light-emitting diodes are significantly improved by employing a zinc phthalocyanine （ZnPc）-based composite hole transport layer （c-HTL）. The optimum ris-（8-hydroxyquinoline）aluminum （Alq3）-based organic light-emitting diode with a c-HTL exhibits a lower turn-on voltage of 2.8 V, a higher maximum current efficiency of 3.40 cd/A and a higher maximum power efficiency of 1.91 lm/W, which are superior to those of the conventional device （turn-on voltage of 3.8 V, maximum current efficiency of 2.60 cd/A, and maximum power efficiency of 1.21 lm/W）. We systematically studied the effects of different kinds of N’-diphenyl-N,N’-bis（1-naphthyl）（1,1’-biphenyl）-4,4’diamine （NPB）：ZnPc c-HTL. Meanwhile, we also investigate their mechanisms different from that in the case of using ZnPc as buffer layer. The specific analysis is based on the absorption spectra of the hole transporting material and current density–voltage characteristics of the corresponding hole-only devices.
基金financially supported by the National Natural Science Foundation of China(Grant No.21777072)。
文摘Zinc(Zn) is an essential mineral element for plant growth and development. Zn deficiency in crops frequently occurs in many types of soils. It is therefore crucial to identify genetic resources linking Zn acquisition traits and development of crops with improved Zn-use efficiency for sustainable crop production. In this study, we functionally identified a rice uncharacterized ABCG(ATP-binding cassette G-subfamily) gene encoding a PDR20(pleiotropic drug resistance 20) metal transporter for mediation of rice growth, seed development and Zn accumulation. OsPDR20 was localized to the plasma membrane, but it was not transcriptionally induced under Zn deficiency, rather was sufficiently up-regulated under high level of Zn stress. Yeast(Saccharomyces cerevisiae) transformed with OsPDR20 displayed a relatively lower Zn accumulation with attenuated cellular growth, suggesting that OsPDR20 had an activity for Zn transport. Knocking-down OsPDR20 by RNA interference(RNAi) compromised rice growth with shorter plant height and decreased biomass in rice plantlets grown under hydroponic media. Zn concentration in the roots of OsPDR20 knocked-down rice lines declined under Zn deficiency, while they remained unchanged compared with the wild type under normal Zn supply. A rice lifelong field trial demonstrated that OsPDR20 mutation impaired the capacity of seed development, with shortened panicle and seed length, compromised spikelet fertility, and reduced grain number per plant or grain weight per unit area. Interestingly, OsPDR20 mutation elevated the accumulation of Zn in husk and brown rice over the wild type. Overall, this study pointed out that OsPDR20 is fundamentally required for rice growth and seed development through Zn transport and homeostasis.
