目的探讨钙离子敏感受体(CaSR)与肾结石发生风险的关系。方法运用关键词在Pubmed, Web of Science和OVID等学术搜索引擎上进行检索相关文献,根据入选标准纳入符合要求的文献。采用stata 10.0软件进行统计分析。结果基于9篇文章的12个病...目的探讨钙离子敏感受体(CaSR)与肾结石发生风险的关系。方法运用关键词在Pubmed, Web of Science和OVID等学术搜索引擎上进行检索相关文献,根据入选标准纳入符合要求的文献。采用stata 10.0软件进行统计分析。结果基于9篇文章的12个病例对照,包含2 269个病例和2 637个对照。分析结果汇总显示Arg990Gly基因多态性而非Ala986Ser或Glu1011Gln基因多态性与肾结石发生风险存在相关性。分层分析中,Arg990Gly基因多态性能够增加高加索人群、健康对照的研究人群的肾结石发生风险。Ala986Ser基因多态性能够增加亚洲人群、健康对照的研究人群的肾结石发生风险,降低原发性甲状旁腺功能亢进患者的肾结石发生风险。结论Arg990Gly能够增加人群中肾结石发生风险,尤其在高加索人群、健康对照的研究人群。而Ala986Ser基因多态性能够增加亚洲人群、健康对照的研究人群的肾结石发生风险,降低原发性甲状旁腺功能亢进患者的肾结石发生风险。展开更多
This study focused on the influences of opioids on the generation of antibody against sheep erythrocyte in vitro, It was found that morphine. a-CAO, DADLE, MENK were able to inhibit the capacity of murine spleen cell...This study focused on the influences of opioids on the generation of antibody against sheep erythrocyte in vitro, It was found that morphine. a-CAO, DADLE, MENK were able to inhibit the capacity of murine spleen cells to generate antibody and leukotriene C4 and conversely. dynorphin was able to stimulate the capacity of murine spleen cells to generate antibody and leukotriene C4. Morphine, a-CAO, MENK, DADLE, dynorphin decreased intracellular cAMP level, increased [Ca(2+)]i and calmodulin activity. The effects were completely blocked by naloxone, the specific opioid antagonist. Our results showed that opioids regulate the production of antibody in murine spleen cells, and alter intracellular cAMP, [Ca(2+)]i calmodulin activity. and leukotriene C4 production by way of binding to different receptor types.展开更多
Objective To investigate the effect of D-AP5 (D-2-amino-5-phosphonopentanoate, a specific NMDA-antagonist) on the increase of intracellular free Ca 2+ concentration ([Ca 2+ ] i) induced by glutamate in isol...Objective To investigate the effect of D-AP5 (D-2-amino-5-phosphonopentanoate, a specific NMDA-antagonist) on the increase of intracellular free Ca 2+ concentration ([Ca 2+ ] i) induced by glutamate in isolated cochlear inner hair cells (IHCs), and to detect the autoreceptors of the IHC membrane. Methods When a laser scanning confocal microscope (LSCM) was used, the exogenous glutamate (Glu)-induced changes in [Ca 2+ ] i of isolated IHCs and OHCs of guinea pig cochlea were observed with fluo-3, a fluorescent probe for [Ca 2+ ] i. After D-AP5 or CNQX (6--cyano--7--nitroguinoxaline--2, 3--dione, a specific AMPA- antagonist) was administrated, the exogenous glutamate (Glu)-induced changes in [Ca 2+ ] i of isolated IHCs were recorded. Results In the presence of a low concentration Glu (3.85?μmol/L), there was an increase of [Ca 2+ ] i in IHCs, whereas there was no change in OHCs. When 50?μmol/L of D-AP5 was administrated in advance, Glu did not induce a corresponding increase in [Ca 2+ ] i in IHCs, and 50?μmol/L of CNQX did not completely block the increase of [Ca 2+ ] i in IHCs. Conclusions These results suggest that the autoreceptors existing in the IHC membrane are mainly of NMDA type, while there are relatively few AMPA receptors. Exogenous Glu is capable of increasing [Ca 2+ ] i in IHCs by acting on the NMDA autoreceptor of IHCs in a positive feedback manner.展开更多
As a crucial signaling molecule, calcium plays a critical role in many physiological and pathological processes by regulating ion channel activity. Recently, one study resolved the structure of the transient receptor ...As a crucial signaling molecule, calcium plays a critical role in many physiological and pathological processes by regulating ion channel activity. Recently, one study resolved the structure of the transient receptor potential melastatin 2(TRPM2) channel from Nematostella vectensis(nvTRPM2). This identified a calcium-binding site in the S2–S3 loop, while its effect on channel gating remains unclear. Here, we investigated the role of this calcium-binding site in both nvTRPM2 and human TRPM2(hTRPM2) by mutagenesis and patch-clamp recording. Unlike hTRPM2, nvT RPM2 cannot be activated by calcium alone. Moreover, the inactivation rate of nvTRPM2 was decreased as intracellular calcium concentration was increased. In addition, our results showed that the four key residues in the calcium-binding site of S2–S3 loop have similar effects on the gating processes of nvTRPM2 and hTRPM2. Among them, the mutations at negatively charged residues(glutamate and aspartate) substantially decreased the currents of nvT RPM2 and hTRPM2. This suggests that these sites are essential for calcium-dependent channel gating. For the charge-neutralizing residues(glutamine and asparagine) in the calcium-binding site, our data showed that glutamine mutating to alanine or glutamate did not affect the channel activity, but glutamine mutating to lysine caused loss of function. Asparagine mutating to aspartate still remained functional, while asparagine mutating to alanine or lysine led to little channel activity. These results suggest that the side chain of glutamine has a less contribution to channel gating than does asparagine. However, our data indicated that both glutamine mutating to alanine or glutamate and asparagine mutating to aspartate accelerated the channel inactivation rate, suggesting that the calcium-binding site in the S2–S3 loop is important for calcium-dependent channel inactivation. Taken together, our results uncovered the effect of four key residues in the S2–S3 loop of TRPM2 on the TRPM2 gating process.展开更多
文摘目的探讨钙离子敏感受体(CaSR)与肾结石发生风险的关系。方法运用关键词在Pubmed, Web of Science和OVID等学术搜索引擎上进行检索相关文献,根据入选标准纳入符合要求的文献。采用stata 10.0软件进行统计分析。结果基于9篇文章的12个病例对照,包含2 269个病例和2 637个对照。分析结果汇总显示Arg990Gly基因多态性而非Ala986Ser或Glu1011Gln基因多态性与肾结石发生风险存在相关性。分层分析中,Arg990Gly基因多态性能够增加高加索人群、健康对照的研究人群的肾结石发生风险。Ala986Ser基因多态性能够增加亚洲人群、健康对照的研究人群的肾结石发生风险,降低原发性甲状旁腺功能亢进患者的肾结石发生风险。结论Arg990Gly能够增加人群中肾结石发生风险,尤其在高加索人群、健康对照的研究人群。而Ala986Ser基因多态性能够增加亚洲人群、健康对照的研究人群的肾结石发生风险,降低原发性甲状旁腺功能亢进患者的肾结石发生风险。
文摘This study focused on the influences of opioids on the generation of antibody against sheep erythrocyte in vitro, It was found that morphine. a-CAO, DADLE, MENK were able to inhibit the capacity of murine spleen cells to generate antibody and leukotriene C4 and conversely. dynorphin was able to stimulate the capacity of murine spleen cells to generate antibody and leukotriene C4. Morphine, a-CAO, MENK, DADLE, dynorphin decreased intracellular cAMP level, increased [Ca(2+)]i and calmodulin activity. The effects were completely blocked by naloxone, the specific opioid antagonist. Our results showed that opioids regulate the production of antibody in murine spleen cells, and alter intracellular cAMP, [Ca(2+)]i calmodulin activity. and leukotriene C4 production by way of binding to different receptor types.
文摘Objective To investigate the effect of D-AP5 (D-2-amino-5-phosphonopentanoate, a specific NMDA-antagonist) on the increase of intracellular free Ca 2+ concentration ([Ca 2+ ] i) induced by glutamate in isolated cochlear inner hair cells (IHCs), and to detect the autoreceptors of the IHC membrane. Methods When a laser scanning confocal microscope (LSCM) was used, the exogenous glutamate (Glu)-induced changes in [Ca 2+ ] i of isolated IHCs and OHCs of guinea pig cochlea were observed with fluo-3, a fluorescent probe for [Ca 2+ ] i. After D-AP5 or CNQX (6--cyano--7--nitroguinoxaline--2, 3--dione, a specific AMPA- antagonist) was administrated, the exogenous glutamate (Glu)-induced changes in [Ca 2+ ] i of isolated IHCs were recorded. Results In the presence of a low concentration Glu (3.85?μmol/L), there was an increase of [Ca 2+ ] i in IHCs, whereas there was no change in OHCs. When 50?μmol/L of D-AP5 was administrated in advance, Glu did not induce a corresponding increase in [Ca 2+ ] i in IHCs, and 50?μmol/L of CNQX did not completely block the increase of [Ca 2+ ] i in IHCs. Conclusions These results suggest that the autoreceptors existing in the IHC membrane are mainly of NMDA type, while there are relatively few AMPA receptors. Exogenous Glu is capable of increasing [Ca 2+ ] i in IHCs by acting on the NMDA autoreceptor of IHCs in a positive feedback manner.
基金Project supported by the National Natural Science Foundation oX f China(Nos.81371302,81571127,and 31872796)the National Basic Research Program(973)of China(No.2014CB910300)+1 种基金the National Major New Drugs Innovation and Development(No.2018ZX X09711001-004-005)the Zhejiang Provincial Natural Science Foundation of China(Nos.LR16H090001 and LY19B020013)
文摘As a crucial signaling molecule, calcium plays a critical role in many physiological and pathological processes by regulating ion channel activity. Recently, one study resolved the structure of the transient receptor potential melastatin 2(TRPM2) channel from Nematostella vectensis(nvTRPM2). This identified a calcium-binding site in the S2–S3 loop, while its effect on channel gating remains unclear. Here, we investigated the role of this calcium-binding site in both nvTRPM2 and human TRPM2(hTRPM2) by mutagenesis and patch-clamp recording. Unlike hTRPM2, nvT RPM2 cannot be activated by calcium alone. Moreover, the inactivation rate of nvTRPM2 was decreased as intracellular calcium concentration was increased. In addition, our results showed that the four key residues in the calcium-binding site of S2–S3 loop have similar effects on the gating processes of nvTRPM2 and hTRPM2. Among them, the mutations at negatively charged residues(glutamate and aspartate) substantially decreased the currents of nvT RPM2 and hTRPM2. This suggests that these sites are essential for calcium-dependent channel gating. For the charge-neutralizing residues(glutamine and asparagine) in the calcium-binding site, our data showed that glutamine mutating to alanine or glutamate did not affect the channel activity, but glutamine mutating to lysine caused loss of function. Asparagine mutating to aspartate still remained functional, while asparagine mutating to alanine or lysine led to little channel activity. These results suggest that the side chain of glutamine has a less contribution to channel gating than does asparagine. However, our data indicated that both glutamine mutating to alanine or glutamate and asparagine mutating to aspartate accelerated the channel inactivation rate, suggesting that the calcium-binding site in the S2–S3 loop is important for calcium-dependent channel inactivation. Taken together, our results uncovered the effect of four key residues in the S2–S3 loop of TRPM2 on the TRPM2 gating process.
