BACKGROUND： The pharmacological action of opioid drugs is related to signal transduction of inhibitory guanine nucleotide binding protein. OBJECTIVE： To quantitatively and qualitatively analyze the influence of morp...BACKGROUND： The pharmacological action of opioid drugs is related to signal transduction of inhibitory guanine nucleotide binding protein. OBJECTIVE： To quantitatively and qualitatively analyze the influence of morphine on levels of type Ⅱ inhibitory guanine nucleotide binding protein （Gi2 protein） in primary cultured hippocampal neurons at different time points. DESIGN, TIME AND SETTING： A randomized controlled study, which was performed at the Department of Neurobiology, Changzheng Hospital, Second Military Medical University of Chinese PLA between September 2002 and March 2004. MATERIALS： Cerebral hippocampal neurons were obtained from newborn SD rats at 1 2 days of age. Biotin-antibody Ⅱ-avidin fluorescein isothiocyanate （Avidin-FITC） was purchased from Sigma Company （USA） and the Gi2 protein polyclonal antibody from Santa Cruz Biochemistry Company （USA）. METHODS： Seven days after culture, mature hippocampal neurons were randomly divided into six groups： 4-, 8-, 16-, 24-, and 48-hour morphine groups, and a blank control group. Neurons in the morphine groups received morphine （10 μ mol/L）, which could cause alterations of G-protein mRNA and cAMP expression in the prefrontal cortex. Neurons in the blank control group were given the same volume of saline. MAIN OUTCOME MEASURES： Gi2 protein levels were detected by an immunofluorescence technique, and were analyzed by the image analytic system with the use of green fluorescence intensity. RESULTS： Gi2 protein levels in hippocampal neurons gradually decreased in the 4-, 8-, 16-, 24-, and 48-hour morphine groups. In particular, Gi2 protein levels in the 16-, 24-, and 48-hour morphine groups were significantly lower than that in the blank control group （P 〈 0.05 0.01）. CONCLUSION： Morphine may decrease Gi2 protein level in primary hippocampal neurons, and the decreasing trend is positively related to morphine-induced time.展开更多
BACKGROUND： Drug addiction involves two main central nervous systems, namely the dopamine and noradrenaline systems. These systems are primarily distributed in five brain regions： the ventral tegmental area, the nuc...BACKGROUND： Drug addiction involves two main central nervous systems, namely the dopamine and noradrenaline systems. These systems are primarily distributed in five brain regions： the ventral tegmental area, the nucleus accumbens, the prefrontal cortex, the hippocampus, and the locus coeruleus. OBJECTIVE： To investigate regional changes of guanine nucleotide binding protein-inhabitant 2 （Gi2） in dopaminergic and noradrenergic neurons in brains of morphine-tolerant and -dependent rats. DESIGN, TIME, AND SETTING： A randomized control study was performed at the Department of Neurobiology in the Second Military Medical University of Chinese PLA （Shanghai, China） between September 2002 and March 2004. MATERIALS： Thirty-six, healthy, male, Sprague-Dawley （SD） rats were used to establish morphine-dependent models. Morphine hydrochloride was a product of Shenyang First Pharmaceutical Factory （China）; naloxone hydrochloride was a product of Beijing Four-Ring Pharmaceutical Factory （China）; and α subunit of Gi2 antibody was offered by Santa Cruz Biotechnology, lnc （USA）. METHODS： Thirty-six SD rats were randomly divided into six groups （n = 6）： （1） acute morphine-dependent group, （2） acute abstinent group, （3） acute control group, （4） chronic morphine-dependent group, （5） chronic abstinent group, and （6） chronic control group. Rats in the acute morphine-dependent and the acute groups were injected with morphine （5 mg/kg）, one injection every two hours, for a total of eight injections. In the acute and chronic morphine-dependent rat models, morphine withdrawal syndrome was precipitated by an injection of naloxone （5 mg/kg）. Rats in the acute control group were given a peritoneal injection of physiological saline at the same administration time as the above two groups. Rats in the chronic morphine-dependent and chronic abstinent groups were injected with morphine three times per day. The administration dose on day 1 was initially 5 mg/kg at 20：00, which increased by 5 mg/kg at 8：00, 12：00, and 20：00 until day 7. On day 13, the dose continuously increased by 10 mg/kg until a chronic morphine-dependent rat model was successfully induced. Afterwards, the rats presented with withdrawal syndromes on naloxone （5 mg/kg） at 8：00 on the same day. Rats in the chronic control group were injected with physiological saline at the same time of the two chronic groups. MAIN OUTCOME MEASURES： The concentration of Gi2 protein in the five brain regions （ventral tegmental area, nucleus accumbens, prefrontal cortex, locus coeruleus, and hippocampus） was detected by immunohistochemistry. RESULTS： In the acute morphine-dependent and acute abstinent groups, Gi2 protein concentration was significantly decreased in the nucleus accumbens, compared to the acute control group （P 〈 0.01）, while no obvious changes were detected in other brain regions. In the chronic morphine-dependent and chronic abstinent groups, Gi2 protein concentration was significantly decreased in the nucleus accumbens, but significantly increased in the locus coeruleus （P 〈 0.01 ） compared to the chronic control group. CONCLUSION： Morphine dependence and tolerance may induce obvious reductions of Gi2 protein levels in the nucleus accumbens of rats. Chronic morphine dependence desensitizes the homologous neurons.展开更多
MgCdc42 （Cdc42 in Magnaporthe grisea）, with high homology to ScCdc42 （Cdc42 in Saccharomyces cerevisiae）, has been demonstrated to involve in the morphogenesis and infection process. To further understand the sign...MgCdc42 （Cdc42 in Magnaporthe grisea）, with high homology to ScCdc42 （Cdc42 in Saccharomyces cerevisiae）, has been demonstrated to involve in the morphogenesis and infection process. To further understand the signaling network, the putative MgCdc42-interacting proteins were analyzed. ScCdc42-interacting protein sequences were first used to BLAST against the M. grisea genome database to retrieve their corresponding analogs. Subsequently, conserved domains of these proteins were compared and expression patterns of their encoding genes in different MgCdc42 mutation states were analyzed by semiquantitative RT-PCR. All retrieved analogs of ScCdc42-interacting proteins from the M. grisea database have conserved domains as those in S. cerevisiae. Expression of their encoding genes increased in MgCdc42CA mutant and decreased in MgCdc42KO mutant. However, MgBeml, Chin1, and MgGicl in MgCdc42DN mutant had the same expression level as that in the wild type, although MgBem4, MgBoi2, MgCdc24, MgGic2, MgRgal, and Mst20 had decreased expression level, as expected. Overall, it is concluded that there may exist a similar Cdc42 signal pathway in M. grisea as in S. cerevisiae and MgCdc42 plays a key role in the pathway.展开更多
Adenine is an essential building block of genetic material and a range of coenzymes.Chemical probes containing an adenine moiety have been used in kinase profiling studies in cell lysates.Here we report that adenine-d...Adenine is an essential building block of genetic material and a range of coenzymes.Chemical probes containing an adenine moiety have been used in kinase profiling studies in cell lysates.Here we report that adenine-derived small-molecule probes with an activated ester reactive group can covalently modify a conserved lysine residue of protein kinases and capture a number of nucleotide-binding proteins within living cells.展开更多
Background:The nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3) inflammasome composed of NLRP3,apoptosis-associated speck-like protein containing CARD (ASC),and caspase-1 is engaged in the...Background:The nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3) inflammasome composed of NLRP3,apoptosis-associated speck-like protein containing CARD (ASC),and caspase-1 is engaged in the inflammatory response of many kidney diseases and can be activated by purinergic 2X7 receptor (P2X7R).This study was conducted to explore whether P2X7R plays a pathogenic role in the podocyte damage of obesity-related glomerulopathy (ORG) and whether this role is mediated by the activation ofNLRP3 inflammasome.Methods:A mouse model of ORG was established by high-fat diet feeding.The conditionally immortalized mouse podocytes were cultured with leptin or with leptin and P2X7R antagonist (KN-62 or A438079).The mRNA and protein expression of the P2X7R and NLRP3 inflammasome components including NLRP3,ASC,and caspase-1,as well as the podocyte-associated molecules including nephrin,podocin,and desmin in mouse renal cortex or cultured mouse podocytes were tested by real-time-polymerase chain reaction and Westem blot analysis,respectively.Results:The significantly upregulated expression of P2X7R and NLRP3 inflammasome components and the NLRP3 inflammasome activation were observed in the renal cortex (in fact their location in podocytes was proved by confocal microscopy) of ORG mice in vivo,which were accompanied with the morphological changes of podocyte damage and the expression changes of podocyte-associated molecules.Similar changes in the expression of P2X7R and NLRP3 inflammasome components as well as in the expression ofpodocyte-associated molecules were also observed in the cultured podocyte studies treated by leptin in vitro,and all of the above changes were significantly attenuated by the P2X7R antagonist KN-62 or A438079.Conclusions:P2X7R could trigger the activation ofNLRP3 inflammasome,and the activated P2X7R/NLRP3 inflammasome in podocytes might be involved in the podocyte damage of ORG.展开更多
目的探讨鸟嘌呤核苷酸交换因子C3G/Rap1酶和鸟嘌呤核苷酸交换因子Dock180/Rac1酶信号通路在卵巢癌浸润中的可能作用。方法 Western blot检测Dock180沉默的卵巢癌细胞SKOV3中C3G的表达,验证上皮性卵巢癌组织中Dock180与C3G的表达相关性;...目的探讨鸟嘌呤核苷酸交换因子C3G/Rap1酶和鸟嘌呤核苷酸交换因子Dock180/Rac1酶信号通路在卵巢癌浸润中的可能作用。方法 Western blot检测Dock180沉默的卵巢癌细胞SKOV3中C3G的表达,验证上皮性卵巢癌组织中Dock180与C3G的表达相关性;免疫组化比较卵巢癌组织中Dock180与C3G的表达趋势;免疫荧光观察SKOV3中Dock180与C3G及它们各自的下游蛋白Rac1/Rap1的定位。结果 Dock180基因沉默的细胞中C3G表达明显增强(P<0.05);Dock180与C3G在卵巢癌组织中的表达呈现相反趋势(P<0.05);C3G/Dock180均主要分布于细胞质,下游效应蛋白Rap1/Rac1在细胞膜和细胞质都有表达,但Rap1以细胞质为主,而Rac1可以伸展至细胞膜及细胞膜皱褶。结论卵巢癌细胞和组织中C3G与Dock180表达呈相反趋势,下游蛋白Rap1与Rac1在细胞内的定位分布差异,可能与C3G/Rap1和Dock180/Rac1信号通路在卵巢肿瘤浸润中的不同作用有关。展开更多
The exsitence of GTP binding regulatory proteins (for short term, often refered as G proteins) in higher plant cells is certain. G proteins are classified into two groups based on their molecular structures, which are...The exsitence of GTP binding regulatory proteins (for short term, often refered as G proteins) in higher plant cells is certain. G proteins are classified into two groups based on their molecular structures, which are the heterotrimeric G proteins (big G proteins) that contain three different subunits and the small G proteins that have only one subunit (monomeric G proteins). All G proteins are characterized by their properties to bind with and hydrolyze GTP, by which G proteins function as transmembrane and intracellular signalling molecules. As a distinguished participant in signal transduction, G proteins directly and/or indirectly regulate a number of physiological processes, such as regulation of phytochrome related physiological processes and gene expression, involvement in blue light response, K + channel regulation, stomatal movement, hormone regulation, protein phosphrylation/dephosphorylation, etc. Although G proteins in plant cells have not been purified, the genes for α subunit of heterotrimeric G proteins have been cloned. More evidences for the importance of G proteins in plant signalling processes are rapidly accumulating.展开更多
文摘BACKGROUND： The pharmacological action of opioid drugs is related to signal transduction of inhibitory guanine nucleotide binding protein. OBJECTIVE： To quantitatively and qualitatively analyze the influence of morphine on levels of type Ⅱ inhibitory guanine nucleotide binding protein （Gi2 protein） in primary cultured hippocampal neurons at different time points. DESIGN, TIME AND SETTING： A randomized controlled study, which was performed at the Department of Neurobiology, Changzheng Hospital, Second Military Medical University of Chinese PLA between September 2002 and March 2004. MATERIALS： Cerebral hippocampal neurons were obtained from newborn SD rats at 1 2 days of age. Biotin-antibody Ⅱ-avidin fluorescein isothiocyanate （Avidin-FITC） was purchased from Sigma Company （USA） and the Gi2 protein polyclonal antibody from Santa Cruz Biochemistry Company （USA）. METHODS： Seven days after culture, mature hippocampal neurons were randomly divided into six groups： 4-, 8-, 16-, 24-, and 48-hour morphine groups, and a blank control group. Neurons in the morphine groups received morphine （10 μ mol/L）, which could cause alterations of G-protein mRNA and cAMP expression in the prefrontal cortex. Neurons in the blank control group were given the same volume of saline. MAIN OUTCOME MEASURES： Gi2 protein levels were detected by an immunofluorescence technique, and were analyzed by the image analytic system with the use of green fluorescence intensity. RESULTS： Gi2 protein levels in hippocampal neurons gradually decreased in the 4-, 8-, 16-, 24-, and 48-hour morphine groups. In particular, Gi2 protein levels in the 16-, 24-, and 48-hour morphine groups were significantly lower than that in the blank control group （P 〈 0.05 0.01）. CONCLUSION： Morphine may decrease Gi2 protein level in primary hippocampal neurons, and the decreasing trend is positively related to morphine-induced time.
文摘BACKGROUND： Drug addiction involves two main central nervous systems, namely the dopamine and noradrenaline systems. These systems are primarily distributed in five brain regions： the ventral tegmental area, the nucleus accumbens, the prefrontal cortex, the hippocampus, and the locus coeruleus. OBJECTIVE： To investigate regional changes of guanine nucleotide binding protein-inhabitant 2 （Gi2） in dopaminergic and noradrenergic neurons in brains of morphine-tolerant and -dependent rats. DESIGN, TIME, AND SETTING： A randomized control study was performed at the Department of Neurobiology in the Second Military Medical University of Chinese PLA （Shanghai, China） between September 2002 and March 2004. MATERIALS： Thirty-six, healthy, male, Sprague-Dawley （SD） rats were used to establish morphine-dependent models. Morphine hydrochloride was a product of Shenyang First Pharmaceutical Factory （China）; naloxone hydrochloride was a product of Beijing Four-Ring Pharmaceutical Factory （China）; and α subunit of Gi2 antibody was offered by Santa Cruz Biotechnology, lnc （USA）. METHODS： Thirty-six SD rats were randomly divided into six groups （n = 6）： （1） acute morphine-dependent group, （2） acute abstinent group, （3） acute control group, （4） chronic morphine-dependent group, （5） chronic abstinent group, and （6） chronic control group. Rats in the acute morphine-dependent and the acute groups were injected with morphine （5 mg/kg）, one injection every two hours, for a total of eight injections. In the acute and chronic morphine-dependent rat models, morphine withdrawal syndrome was precipitated by an injection of naloxone （5 mg/kg）. Rats in the acute control group were given a peritoneal injection of physiological saline at the same administration time as the above two groups. Rats in the chronic morphine-dependent and chronic abstinent groups were injected with morphine three times per day. The administration dose on day 1 was initially 5 mg/kg at 20：00, which increased by 5 mg/kg at 8：00, 12：00, and 20：00 until day 7. On day 13, the dose continuously increased by 10 mg/kg until a chronic morphine-dependent rat model was successfully induced. Afterwards, the rats presented with withdrawal syndromes on naloxone （5 mg/kg） at 8：00 on the same day. Rats in the chronic control group were injected with physiological saline at the same time of the two chronic groups. MAIN OUTCOME MEASURES： The concentration of Gi2 protein in the five brain regions （ventral tegmental area, nucleus accumbens, prefrontal cortex, locus coeruleus, and hippocampus） was detected by immunohistochemistry. RESULTS： In the acute morphine-dependent and acute abstinent groups, Gi2 protein concentration was significantly decreased in the nucleus accumbens, compared to the acute control group （P 〈 0.01）, while no obvious changes were detected in other brain regions. In the chronic morphine-dependent and chronic abstinent groups, Gi2 protein concentration was significantly decreased in the nucleus accumbens, but significantly increased in the locus coeruleus （P 〈 0.01 ） compared to the chronic control group. CONCLUSION： Morphine dependence and tolerance may induce obvious reductions of Gi2 protein levels in the nucleus accumbens of rats. Chronic morphine dependence desensitizes the homologous neurons.
基金the National Natural Science Foundation of China to Wang Zonghua （30070030, 30470066）.
文摘MgCdc42 （Cdc42 in Magnaporthe grisea）, with high homology to ScCdc42 （Cdc42 in Saccharomyces cerevisiae）, has been demonstrated to involve in the morphogenesis and infection process. To further understand the signaling network, the putative MgCdc42-interacting proteins were analyzed. ScCdc42-interacting protein sequences were first used to BLAST against the M. grisea genome database to retrieve their corresponding analogs. Subsequently, conserved domains of these proteins were compared and expression patterns of their encoding genes in different MgCdc42 mutation states were analyzed by semiquantitative RT-PCR. All retrieved analogs of ScCdc42-interacting proteins from the M. grisea database have conserved domains as those in S. cerevisiae. Expression of their encoding genes increased in MgCdc42CA mutant and decreased in MgCdc42KO mutant. However, MgBeml, Chin1, and MgGicl in MgCdc42DN mutant had the same expression level as that in the wild type, although MgBem4, MgBoi2, MgCdc24, MgGic2, MgRgal, and Mst20 had decreased expression level, as expected. Overall, it is concluded that there may exist a similar Cdc42 signal pathway in M. grisea as in S. cerevisiae and MgCdc42 plays a key role in the pathway.
基金funding support from the National Natural Science Foundation of China(No.81872749)Shenzhen Science and Technology Innovation Commission(Nos.20200815000631001 and JCYJ20200109120414564)Peking University。
文摘Adenine is an essential building block of genetic material and a range of coenzymes.Chemical probes containing an adenine moiety have been used in kinase profiling studies in cell lysates.Here we report that adenine-derived small-molecule probes with an activated ester reactive group can covalently modify a conserved lysine residue of protein kinases and capture a number of nucleotide-binding proteins within living cells.
基金grants from the National Natural Science Foundation of China (No.81573745and No.8160140274)Beijing Municipal Natural Science Foundation (No.7172066) Beijing Development Foundation of Traditional Chinese Medicine (QN2016-23).
文摘Background:The nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3) inflammasome composed of NLRP3,apoptosis-associated speck-like protein containing CARD (ASC),and caspase-1 is engaged in the inflammatory response of many kidney diseases and can be activated by purinergic 2X7 receptor (P2X7R).This study was conducted to explore whether P2X7R plays a pathogenic role in the podocyte damage of obesity-related glomerulopathy (ORG) and whether this role is mediated by the activation ofNLRP3 inflammasome.Methods:A mouse model of ORG was established by high-fat diet feeding.The conditionally immortalized mouse podocytes were cultured with leptin or with leptin and P2X7R antagonist (KN-62 or A438079).The mRNA and protein expression of the P2X7R and NLRP3 inflammasome components including NLRP3,ASC,and caspase-1,as well as the podocyte-associated molecules including nephrin,podocin,and desmin in mouse renal cortex or cultured mouse podocytes were tested by real-time-polymerase chain reaction and Westem blot analysis,respectively.Results:The significantly upregulated expression of P2X7R and NLRP3 inflammasome components and the NLRP3 inflammasome activation were observed in the renal cortex (in fact their location in podocytes was proved by confocal microscopy) of ORG mice in vivo,which were accompanied with the morphological changes of podocyte damage and the expression changes of podocyte-associated molecules.Similar changes in the expression of P2X7R and NLRP3 inflammasome components as well as in the expression ofpodocyte-associated molecules were also observed in the cultured podocyte studies treated by leptin in vitro,and all of the above changes were significantly attenuated by the P2X7R antagonist KN-62 or A438079.Conclusions:P2X7R could trigger the activation ofNLRP3 inflammasome,and the activated P2X7R/NLRP3 inflammasome in podocytes might be involved in the podocyte damage of ORG.
文摘目的探讨鸟嘌呤核苷酸交换因子C3G/Rap1酶和鸟嘌呤核苷酸交换因子Dock180/Rac1酶信号通路在卵巢癌浸润中的可能作用。方法 Western blot检测Dock180沉默的卵巢癌细胞SKOV3中C3G的表达,验证上皮性卵巢癌组织中Dock180与C3G的表达相关性;免疫组化比较卵巢癌组织中Dock180与C3G的表达趋势;免疫荧光观察SKOV3中Dock180与C3G及它们各自的下游蛋白Rac1/Rap1的定位。结果 Dock180基因沉默的细胞中C3G表达明显增强(P<0.05);Dock180与C3G在卵巢癌组织中的表达呈现相反趋势(P<0.05);C3G/Dock180均主要分布于细胞质,下游效应蛋白Rap1/Rac1在细胞膜和细胞质都有表达,但Rap1以细胞质为主,而Rac1可以伸展至细胞膜及细胞膜皱褶。结论卵巢癌细胞和组织中C3G与Dock180表达呈相反趋势,下游蛋白Rap1与Rac1在细胞内的定位分布差异,可能与C3G/Rap1和Dock180/Rac1信号通路在卵巢肿瘤浸润中的不同作用有关。
文摘The exsitence of GTP binding regulatory proteins (for short term, often refered as G proteins) in higher plant cells is certain. G proteins are classified into two groups based on their molecular structures, which are the heterotrimeric G proteins (big G proteins) that contain three different subunits and the small G proteins that have only one subunit (monomeric G proteins). All G proteins are characterized by their properties to bind with and hydrolyze GTP, by which G proteins function as transmembrane and intracellular signalling molecules. As a distinguished participant in signal transduction, G proteins directly and/or indirectly regulate a number of physiological processes, such as regulation of phytochrome related physiological processes and gene expression, involvement in blue light response, K + channel regulation, stomatal movement, hormone regulation, protein phosphrylation/dephosphorylation, etc. Although G proteins in plant cells have not been purified, the genes for α subunit of heterotrimeric G proteins have been cloned. More evidences for the importance of G proteins in plant signalling processes are rapidly accumulating.
