AIM To investigate the role of calmodulin-dependent protein kinase Ⅱ(Ca MKⅡ) in colon cancer growth,migration and invasion.METHODS Ca MKⅡ expression in colon cancer and paracancerous tissues was evaluated via immun...AIM To investigate the role of calmodulin-dependent protein kinase Ⅱ(Ca MKⅡ) in colon cancer growth,migration and invasion.METHODS Ca MKⅡ expression in colon cancer and paracancerous tissues was evaluated via immunochemistry. Transcriptional and posttranscriptional levels of Ca MKⅡin tissue samples and MMP2,MMP9 and TIMP-1 expression in the human colon cancer cell line HCT116 were assessed by q RTPCR and western blot. Cell proliferation was detected with the MTT assay. Cancer cell migration and invasion were investigated with the Transwell culture system and woundhealing assay.RESULTS We first demonstrated that CaMK Ⅱ was ove rexpressed in human colon cancers and was associated with cancer differentiation. In the human colon cancer cell line HCT116,the Ca MKII-specific inhibitor KN93,but not its inactive analogue KN92,decreased cancer cell proliferation. Furthermore,KN93 also significantly prohibited HCT116 cell migration and invasion. The specific inhibition of ERK1/2 or p38 decreased the proliferation and migration of colon cancer cells.CONCLUSION Our findings highlight Ca MKⅡ as a potential critical mediator in human colon tumor development and metastasis.展开更多
Cardiac hypertrophy is an independent risk factor for sudden cardiac death in clinical settings and the incidence of sudden cardiac death and ventricular arrhythmias are closely related.The aim of this study was to de...Cardiac hypertrophy is an independent risk factor for sudden cardiac death in clinical settings and the incidence of sudden cardiac death and ventricular arrhythmias are closely related.The aim of this study was to determine the effects of the calmodulin-dependent protein kinase(CaMK) Ⅱ inhibitor,KN-93,on L-type calcium current(I Ca,L) and early after-depolarizations(EADs) in hypertrophic cardiomyocytes.A rabbit model of myocardial hypertrophy was constructed through abdominal aortic coarctation(LVH group).The control group(sham group) received a sham operation,in which the abdominal aortic was dissected but not coarcted.Eight weeks later,the degree of left ventricular hypertrophy(LVH) was evaluated using echocardiography.Individual cardiomyocyte was isolated through collagenase digestion.Action potentials(APs) and I Ca,L were recorded using the perforated patch clamp technique.APs were recorded under current clamp conditions and I Ca,L was recorded under voltage clamp conditions.The incidence of EADs and I ca,L in the hypertrophic cardiomyocytes were observed under the conditions of low potassium(2 mmol/L),low magnesium(0.25 mmol/L) Tyrode’s solution perfusion,and slow frequency(0.25-0.5 Hz) electrical stimulation.The incidence of EADs and I ca,L in the hypertrophic cardiomyocytes were also evaluated after treatment with different concentrations of KN-92(KN-92 group) and KN-93(KN-93 group).Eight weeks later,the model was successfully established.Under the conditions of low potassium,low magnesium Tyrode’s solution perfusion,and slow frequency electrical stimulation,the incidence of EADs was 0/12,11/12,10/12,and 5/12 in sham group,LVH group,KN-92 group(0.5 μmol/L),and KN-93 group(0.5 μmol/L),respectively.When the drug concentration was increased to 1 μmol/L in KN-92 group and KN-93 group,the incidence of EADs was 10/12 and 2/12,respectively.At 0 mV,the current density was 6.7±1.0 and 6.3±0.7 PA·PF-1 in LVH group and sham group,respectively(P>0.05,n=12).When the drug concentration was 0.5 μmol/L in KN-92 and KN-93 groups,the peak I Ca,L at 0 mV was decreased by(9.4±2.8)% and(10.5±3.0)% in the hypertrophic cardiomyocytes of the two groups,respectively(P>0.05,n=12).When the drug concentration was increased to 1 μmol/L,the peak I Ca,L values were lowered by(13.4±3.7)% and(40±4.9)%,respectively(P<0.01,n=12).KN-93,a specific inhibitor of CaMKII,can effectively inhibit the occurrence of EADs in hypertrophic cardiomyocytes partially by suppressing I Ca,L,which may be the main action mechanism of KN-93 antagonizing the occurrence of ventricular arrhythmias in hypertrophic myocardium.展开更多
In this study, primary cultured cerebral cortical neurons of Sprague-Dawley neonatal rats were treated with 0.25, 0.5, and 1.0 μM calmodulin-dependent protein kinase II inhibitor KN-93 after 50 μM N-methyI-D-asparti...In this study, primary cultured cerebral cortical neurons of Sprague-Dawley neonatal rats were treated with 0.25, 0.5, and 1.0 μM calmodulin-dependent protein kinase II inhibitor KN-93 after 50 μM N-methyI-D-aspartic acid-induced injury. Results showed that, compared with N-methyi-D- aspartic acid-induced injury neurons, the activity of cells markedly increased, apoptosis was significantly reduced, leakage of lactate dehydrogenase decreased, and intracellular Ca2＋ concentrations in neurons reduced after KN-93 treatment. The expression of caspase-3, phosphorylated calmodulin-dependent protein kinase II and total calmodulin-dependent protein kinase II protein decreased after KN-93 treatment. And the effect was apparent at a dose of 1.0 pM KN-93. Experimental findings suggest that KN-93 can induce a dose-dependent neuroprotective effect, and that the underlying mechanism may be related to the down-regulation of caspase-3 and calmodulin- dependent protein kinase II expression.展开更多
Septic encephalopathy is a frequent complication of sepsis,but there are few studies examining the role of micro RNAs（mi Rs） in its pathogenesis.In this study,a mi R-219 mimic was transfected into rat hippocampal ne...Septic encephalopathy is a frequent complication of sepsis,but there are few studies examining the role of micro RNAs（mi Rs） in its pathogenesis.In this study,a mi R-219 mimic was transfected into rat hippocampal neurons to model mi R-219 overexpression.A protective effect of mi R-219 was observed for glutamate-induced neurotoxicity of rat hippocampal neurons,and an underlying mechanism involving calmodulin-dependent protein kinase II γ（Ca MKIIγ） was demonstrated.mi R-219 and Ca MKIIγ m RNA expression induced by glutamate in hippocampal neurons was determined by quantitative real-time reverse transcription-polymerase chain reaction（q RT-PCR）.After neurons were transfected with mi R-219 mimic,effects on cell viability and apoptosis were measured by 3-（4,5-dimethylthiazolyl-2）-2,5-diphenyltetrazolium bromide（MTT） assay and flow cytometry.In addition,a luciferase reporter gene system was used to confirm Ca MKIIγ as a target gene of mi R-219.Western blot assay and rescue experiments were also utilized to detect Ca MKIIγ expression and further verify that mi R-219 in hippocampal neurons exerted its effect through regulation of Ca MKIIγ.MTT assay and q RT-PCR results revealed obvious decreases in cell viability and mi R-219 expression after glutamate stimulation,while Ca MKIIγ m RNA expression was increased.MTT,flow cytometry,and caspase-3 activity assays showed that mi R-219 overexpression could elevate glutamate-induced cell viability,and reduce cell apoptosis and caspase-3 activity.Moreover,luciferase Ca MKIIγ-reporter activity was remarkably decreased by co-transfection with mi R-219 mimic,and the results of a rescue experiment showed that Ca MKIIγ overexpression could reverse the biological effects of mi R-219.Collectively,these findings verify that mi R-219 expression was decreased in glutamate-induced neurons,Ca MKIIγ was a target gene of mi R-219,and mi R-219 alleviated glutamate-induced neuronal excitotoxicity by negatively controlling Ca MKIIγ expression.展开更多
AIM: To examine the role of p38 during acute experimental cerulein pancreatitis. METHODS: Rats were treated with cerulein with or without a specific JNK inhibitor (CEP1347) and/or a specific p38 inhibitor (SB203580) a...AIM: To examine the role of p38 during acute experimental cerulein pancreatitis. METHODS: Rats were treated with cerulein with or without a specific JNK inhibitor (CEP1347) and/or a specific p38 inhibitor (SB203580) and pancreatic stress kinase activity was determined. Parameters to assess pancreatitis included trypsin, amylase, lipase, pancreatic weight and histology. RESULTS: JNK inhibition with CEP1347 ameliorated pancreatitis, reducing pancreatic edema. In contrast, p38 inhibition with SB203580 aggravated pancreatitis with higher trypsin levels and, with induction of acinar necrosis not normally found after cerulein hyperstimulation. Simultaneous treatment with both CEP1347 and SB203580 mutually abolished the effects of either compound on cerulein pancreatitis. CONCLUSION: Stress kinases modulate pancreatitis differentially. JNK seems to promote pancreatitis development, possibly by supporting inflammatory reactions such as edema formation while its inhibition ameliorates pancreatitis. In contrast, p38 may help reduce organ destruction while inhibition of p38 during induction of cerulein pancreatitis leads to the occurrence of acinar necrosis.展开更多
Using nystatin-perforated whole-cell recording configuration, the modulatory effect of N-methyl-D-aspartate (NMDA) on γ-aminobutyric acid (GABA)-activated whole-cell currents was investigated in neurons freshly disso...Using nystatin-perforated whole-cell recording configuration, the modulatory effect of N-methyl-D-aspartate (NMDA) on γ-aminobutyric acid (GABA)-activated whole-cell currents was investigated in neurons freshly dissociated from the rat sacral dorsal commissural nucleus (SDCN). The results showed that: (i) NMDA suppressed GABA- and muscimol (Mus)-activated currents (IGABA and IMUS), respectively in the Mg2+-free external solution containing 1 μmol/L glycine at a holding potential (VH) of -40 mV in SDCN neurons. The selective NMDA receptor antagonist, D-2-amino-5-phosphonovaleric acid (APV, 100 μmol/L), inhibited the NMDA-evoked currents and blocked the NMDA-induced suppression of IGABA; (ii) when the neurons were incubated in a Ca2+-free bath or pre-loaded with a membrane-permeable Ca2+ chelator, BAPTA AM (10 nmol/L), the inhibitory effect of NMDA on IGABA disappeared. Cd2+ (10 μmol/L) or La3+(30 μmol/L), the non-selective blockers of voltage-dependent calcium channels, did not affect the suppression of IGABA by NMDA application; (iii) the suppression of IGABA by NMDA was inhibited by KN-62, a cal-cium/calmodulin-dependent protein kinase II (CaMKII) inhibitor. These results indicated that the inhibition of GABA response by NMDA is Ca2+-dependent and CaMKII is involved in the process of the Ca2+-dependent inhibition.展开更多
A calmodulin-dependent protein kinase (MCK1) appeared important in regulating flowering in tobacco. The expression of modified MCK1 that lacks the C-terminal including calmodulin-binding domain upsets the flowering de...A calmodulin-dependent protein kinase (MCK1) appeared important in regulating flowering in tobacco. The expression of modified MCK1 that lacks the C-terminal including calmodulin-binding domain upsets the flowering developmental program, leading to the abortion of flower primordia initiated on the main axis of the plant and, as well, caused the prolongation of the vegetative phase in axillary buds. The abortion process of flowers began first in the developing anthers and subsequently the entire flower senesces. In axillary buds the prolonged vegetative phase was characterized by atypical elongated, narrow, twisted leaves. These results suggested a role for calmodulin-dependent protein kinase homologs in mediating flowering.展开更多
Many of the effects of Ca^2＋ signaling are mediated through the Ca^2＋/calmodulin complex and its acceptors, the Ca^2＋/calmodulin-dependent protein kinases, including PSKHI. Studies of the proteins involved in the c...Many of the effects of Ca^2＋ signaling are mediated through the Ca^2＋/calmodulin complex and its acceptors, the Ca^2＋/calmodulin-dependent protein kinases, including PSKHI. Studies of the proteins involved in the calcium metabolism in oysters will help elucidate the pearl formation mechanism. This paper describes a full-length PSKH1 cDNA isolated from pearl oyster Pinctada fucata. Oyster PSKH1 shares 65% homology with human PSKH1 and 48% similarity with rat CaM kinase I in the amino acid sequence, and contains a calmodulin-binding domain. The results of semi-quantitative reverse transcription-polymerase chain reaction and in situ hybridization revealed that oyster PSKH1 mRNA is highly expressed in the outer epithelial cells of the mantle pallial and in the gill epithelial cells. These studies provide important information describing the complex Ca^2＋ signaling mechanism in oyster calcium metabolism.展开更多
目的探讨钙调素激酶Ⅳ在心肌肥厚发生中的作用及可能存在的信号转导途径.方法将100只健康雄性SD大鼠(体重150～180g)随机分为对照组(n=50)和心肌肥厚组(n=50),制备腹主动脉缩窄大鼠心肌肥厚模型,模型复制成功后4周以免疫组化法观察左室...目的探讨钙调素激酶Ⅳ在心肌肥厚发生中的作用及可能存在的信号转导途径.方法将100只健康雄性SD大鼠(体重150～180g)随机分为对照组(n=50)和心肌肥厚组(n=50),制备腹主动脉缩窄大鼠心肌肥厚模型,模型复制成功后4周以免疫组化法观察左室心肌钙调素激酶Ⅳ(CaMKⅣ)及磷酸化核转录因子CREB(pCREB)蛋白表达及分布,RT-PCR法检测心肌组织c-fos的mRNA含量.结果 CaMKⅣ及pCREB主要分布于细胞核,心肌肥厚组CaMKⅣ高于对照组(21.63 VS 15.56,P<0.05),pCREB也高于对照组(16.39 VS 11.03,P<0.05);心肌肥厚组心肌组织c-fos的mRNA表达较对照组明显增加(0.58 VS 0.33,P<0.05).结论压力超负荷时CaMKⅣ激活,同时核转录因子CREB磷酸化增加,并引起细胞核内早期基因c-fos表达增加,可能在介导心肌肥厚发生中起重要作用.展开更多
目的:探讨死亡相关蛋白激酶(death-associated protein kinase,DAPK)基因高甲基化与胃癌的发生以及临床病理特征之间的联系。方法:采用甲基化特异性聚合酶链反应(methylation-specific PCR,MSP)法分别检测66例胃癌患者的肿瘤组织、癌旁...目的:探讨死亡相关蛋白激酶(death-associated protein kinase,DAPK)基因高甲基化与胃癌的发生以及临床病理特征之间的联系。方法:采用甲基化特异性聚合酶链反应(methylation-specific PCR,MSP)法分别检测66例胃癌患者的肿瘤组织、癌旁正常组织、手术前外周血浆以及37例术后血浆中DAPK基因启动子的甲基化状况,以20例健康人的外周血浆和胃镜活检正常胃组织作为对照。结果:胃癌组织中有66.7%(44/66)存在DAPK基因的异常甲基化,显著高于相应的癌旁正常组织[10.6%(7/66)],差异有统计学意义(P<0.001)。术前外周血浆中DAPK基因甲基化阳性率为16.7%(11/66);37例同时有胃癌根治术前后血浆标本的患者中,5例术前血浆甲基化阳性,术后全部转阴。而20例健康人的外周血浆和胃镜活检组织中均未检测到该基因甲基化。结论:DAPK基因在胃癌患者肿瘤组织和外周血浆中的高甲基化可能为胃癌的诊断以及临床预后评估提供有益的线索,手术后血浆中DAPK甲基化状态的变化可能与手术治疗有关。展开更多
基金Supported by the National Natural Science Foundation of China,No.81302131
文摘AIM To investigate the role of calmodulin-dependent protein kinase Ⅱ(Ca MKⅡ) in colon cancer growth,migration and invasion.METHODS Ca MKⅡ expression in colon cancer and paracancerous tissues was evaluated via immunochemistry. Transcriptional and posttranscriptional levels of Ca MKⅡin tissue samples and MMP2,MMP9 and TIMP-1 expression in the human colon cancer cell line HCT116 were assessed by q RTPCR and western blot. Cell proliferation was detected with the MTT assay. Cancer cell migration and invasion were investigated with the Transwell culture system and woundhealing assay.RESULTS We first demonstrated that CaMK Ⅱ was ove rexpressed in human colon cancers and was associated with cancer differentiation. In the human colon cancer cell line HCT116,the Ca MKII-specific inhibitor KN93,but not its inactive analogue KN92,decreased cancer cell proliferation. Furthermore,KN93 also significantly prohibited HCT116 cell migration and invasion. The specific inhibition of ERK1/2 or p38 decreased the proliferation and migration of colon cancer cells.CONCLUSION Our findings highlight Ca MKⅡ as a potential critical mediator in human colon tumor development and metastasis.
基金supported by grants from the Fujian Provincial Natural Science Foundation of China (No. 2008J0075)the Fujian Provincial Science and Technology Project of China(No. 2010Y0011)
文摘Cardiac hypertrophy is an independent risk factor for sudden cardiac death in clinical settings and the incidence of sudden cardiac death and ventricular arrhythmias are closely related.The aim of this study was to determine the effects of the calmodulin-dependent protein kinase(CaMK) Ⅱ inhibitor,KN-93,on L-type calcium current(I Ca,L) and early after-depolarizations(EADs) in hypertrophic cardiomyocytes.A rabbit model of myocardial hypertrophy was constructed through abdominal aortic coarctation(LVH group).The control group(sham group) received a sham operation,in which the abdominal aortic was dissected but not coarcted.Eight weeks later,the degree of left ventricular hypertrophy(LVH) was evaluated using echocardiography.Individual cardiomyocyte was isolated through collagenase digestion.Action potentials(APs) and I Ca,L were recorded using the perforated patch clamp technique.APs were recorded under current clamp conditions and I Ca,L was recorded under voltage clamp conditions.The incidence of EADs and I ca,L in the hypertrophic cardiomyocytes were observed under the conditions of low potassium(2 mmol/L),low magnesium(0.25 mmol/L) Tyrode’s solution perfusion,and slow frequency(0.25-0.5 Hz) electrical stimulation.The incidence of EADs and I ca,L in the hypertrophic cardiomyocytes were also evaluated after treatment with different concentrations of KN-92(KN-92 group) and KN-93(KN-93 group).Eight weeks later,the model was successfully established.Under the conditions of low potassium,low magnesium Tyrode’s solution perfusion,and slow frequency electrical stimulation,the incidence of EADs was 0/12,11/12,10/12,and 5/12 in sham group,LVH group,KN-92 group(0.5 μmol/L),and KN-93 group(0.5 μmol/L),respectively.When the drug concentration was increased to 1 μmol/L in KN-92 group and KN-93 group,the incidence of EADs was 10/12 and 2/12,respectively.At 0 mV,the current density was 6.7±1.0 and 6.3±0.7 PA·PF-1 in LVH group and sham group,respectively(P>0.05,n=12).When the drug concentration was 0.5 μmol/L in KN-92 and KN-93 groups,the peak I Ca,L at 0 mV was decreased by(9.4±2.8)% and(10.5±3.0)% in the hypertrophic cardiomyocytes of the two groups,respectively(P>0.05,n=12).When the drug concentration was increased to 1 μmol/L,the peak I Ca,L values were lowered by(13.4±3.7)% and(40±4.9)%,respectively(P<0.01,n=12).KN-93,a specific inhibitor of CaMKII,can effectively inhibit the occurrence of EADs in hypertrophic cardiomyocytes partially by suppressing I Ca,L,which may be the main action mechanism of KN-93 antagonizing the occurrence of ventricular arrhythmias in hypertrophic myocardium.
基金supported by Liaoning Social Development Key Projects of Scientific and Technological Department of Liaoning Province, No. 2012225019
文摘In this study, primary cultured cerebral cortical neurons of Sprague-Dawley neonatal rats were treated with 0.25, 0.5, and 1.0 μM calmodulin-dependent protein kinase II inhibitor KN-93 after 50 μM N-methyI-D-aspartic acid-induced injury. Results showed that, compared with N-methyi-D- aspartic acid-induced injury neurons, the activity of cells markedly increased, apoptosis was significantly reduced, leakage of lactate dehydrogenase decreased, and intracellular Ca2＋ concentrations in neurons reduced after KN-93 treatment. The expression of caspase-3, phosphorylated calmodulin-dependent protein kinase II and total calmodulin-dependent protein kinase II protein decreased after KN-93 treatment. And the effect was apparent at a dose of 1.0 pM KN-93. Experimental findings suggest that KN-93 can induce a dose-dependent neuroprotective effect, and that the underlying mechanism may be related to the down-regulation of caspase-3 and calmodulin- dependent protein kinase II expression.
基金supported by the National Natural Science Foundation of China,No.81101159the Natural Science Foundation of Jiangsu Province of China,No.BK20151268
文摘Septic encephalopathy is a frequent complication of sepsis,but there are few studies examining the role of micro RNAs（mi Rs） in its pathogenesis.In this study,a mi R-219 mimic was transfected into rat hippocampal neurons to model mi R-219 overexpression.A protective effect of mi R-219 was observed for glutamate-induced neurotoxicity of rat hippocampal neurons,and an underlying mechanism involving calmodulin-dependent protein kinase II γ（Ca MKIIγ） was demonstrated.mi R-219 and Ca MKIIγ m RNA expression induced by glutamate in hippocampal neurons was determined by quantitative real-time reverse transcription-polymerase chain reaction（q RT-PCR）.After neurons were transfected with mi R-219 mimic,effects on cell viability and apoptosis were measured by 3-（4,5-dimethylthiazolyl-2）-2,5-diphenyltetrazolium bromide（MTT） assay and flow cytometry.In addition,a luciferase reporter gene system was used to confirm Ca MKIIγ as a target gene of mi R-219.Western blot assay and rescue experiments were also utilized to detect Ca MKIIγ expression and further verify that mi R-219 in hippocampal neurons exerted its effect through regulation of Ca MKIIγ.MTT assay and q RT-PCR results revealed obvious decreases in cell viability and mi R-219 expression after glutamate stimulation,while Ca MKIIγ m RNA expression was increased.MTT,flow cytometry,and caspase-3 activity assays showed that mi R-219 overexpression could elevate glutamate-induced cell viability,and reduce cell apoptosis and caspase-3 activity.Moreover,luciferase Ca MKIIγ-reporter activity was remarkably decreased by co-transfection with mi R-219 mimic,and the results of a rescue experiment showed that Ca MKIIγ overexpression could reverse the biological effects of mi R-219.Collectively,these findings verify that mi R-219 expression was decreased in glutamate-induced neurons,Ca MKIIγ was a target gene of mi R-219,and mi R-219 alleviated glutamate-induced neuronal excitotoxicity by negatively controlling Ca MKIIγ expression.
文摘AIM: To examine the role of p38 during acute experimental cerulein pancreatitis. METHODS: Rats were treated with cerulein with or without a specific JNK inhibitor (CEP1347) and/or a specific p38 inhibitor (SB203580) and pancreatic stress kinase activity was determined. Parameters to assess pancreatitis included trypsin, amylase, lipase, pancreatic weight and histology. RESULTS: JNK inhibition with CEP1347 ameliorated pancreatitis, reducing pancreatic edema. In contrast, p38 inhibition with SB203580 aggravated pancreatitis with higher trypsin levels and, with induction of acinar necrosis not normally found after cerulein hyperstimulation. Simultaneous treatment with both CEP1347 and SB203580 mutually abolished the effects of either compound on cerulein pancreatitis. CONCLUSION: Stress kinases modulate pancreatitis differentially. JNK seems to promote pancreatitis development, possibly by supporting inflammatory reactions such as edema formation while its inhibition ameliorates pancreatitis. In contrast, p38 may help reduce organ destruction while inhibition of p38 during induction of cerulein pancreatitis leads to the occurrence of acinar necrosis.
文摘Using nystatin-perforated whole-cell recording configuration, the modulatory effect of N-methyl-D-aspartate (NMDA) on γ-aminobutyric acid (GABA)-activated whole-cell currents was investigated in neurons freshly dissociated from the rat sacral dorsal commissural nucleus (SDCN). The results showed that: (i) NMDA suppressed GABA- and muscimol (Mus)-activated currents (IGABA and IMUS), respectively in the Mg2+-free external solution containing 1 μmol/L glycine at a holding potential (VH) of -40 mV in SDCN neurons. The selective NMDA receptor antagonist, D-2-amino-5-phosphonovaleric acid (APV, 100 μmol/L), inhibited the NMDA-evoked currents and blocked the NMDA-induced suppression of IGABA; (ii) when the neurons were incubated in a Ca2+-free bath or pre-loaded with a membrane-permeable Ca2+ chelator, BAPTA AM (10 nmol/L), the inhibitory effect of NMDA on IGABA disappeared. Cd2+ (10 μmol/L) or La3+(30 μmol/L), the non-selective blockers of voltage-dependent calcium channels, did not affect the suppression of IGABA by NMDA application; (iii) the suppression of IGABA by NMDA was inhibited by KN-62, a cal-cium/calmodulin-dependent protein kinase II (CaMKII) inhibitor. These results indicated that the inhibition of GABA response by NMDA is Ca2+-dependent and CaMKII is involved in the process of the Ca2+-dependent inhibition.
基金the National Basic Research Program (Grant No. G1999 0116), theNational Science Fund for Outstanding Youth (Grant No. 39725015), the National Natural Science Foundation of China (Grant No. 39780015), the National Fund for Transgenic Project (Grant No.
文摘A calmodulin-dependent protein kinase (MCK1) appeared important in regulating flowering in tobacco. The expression of modified MCK1 that lacks the C-terminal including calmodulin-binding domain upsets the flowering developmental program, leading to the abortion of flower primordia initiated on the main axis of the plant and, as well, caused the prolongation of the vegetative phase in axillary buds. The abortion process of flowers began first in the developing anthers and subsequently the entire flower senesces. In axillary buds the prolonged vegetative phase was characterized by atypical elongated, narrow, twisted leaves. These results suggested a role for calmodulin-dependent protein kinase homologs in mediating flowering.
基金Supported by the National High-Tech Research and Development (863) Program of China (No. 2003AA603430) and the National Natural Science Foundation of China (No. 30371092)
文摘Many of the effects of Ca^2＋ signaling are mediated through the Ca^2＋/calmodulin complex and its acceptors, the Ca^2＋/calmodulin-dependent protein kinases, including PSKHI. Studies of the proteins involved in the calcium metabolism in oysters will help elucidate the pearl formation mechanism. This paper describes a full-length PSKH1 cDNA isolated from pearl oyster Pinctada fucata. Oyster PSKH1 shares 65% homology with human PSKH1 and 48% similarity with rat CaM kinase I in the amino acid sequence, and contains a calmodulin-binding domain. The results of semi-quantitative reverse transcription-polymerase chain reaction and in situ hybridization revealed that oyster PSKH1 mRNA is highly expressed in the outer epithelial cells of the mantle pallial and in the gill epithelial cells. These studies provide important information describing the complex Ca^2＋ signaling mechanism in oyster calcium metabolism.
文摘目的探讨钙调素激酶Ⅳ在心肌肥厚发生中的作用及可能存在的信号转导途径.方法将100只健康雄性SD大鼠(体重150～180g)随机分为对照组(n=50)和心肌肥厚组(n=50),制备腹主动脉缩窄大鼠心肌肥厚模型,模型复制成功后4周以免疫组化法观察左室心肌钙调素激酶Ⅳ(CaMKⅣ)及磷酸化核转录因子CREB(pCREB)蛋白表达及分布,RT-PCR法检测心肌组织c-fos的mRNA含量.结果 CaMKⅣ及pCREB主要分布于细胞核,心肌肥厚组CaMKⅣ高于对照组(21.63 VS 15.56,P<0.05),pCREB也高于对照组(16.39 VS 11.03,P<0.05);心肌肥厚组心肌组织c-fos的mRNA表达较对照组明显增加(0.58 VS 0.33,P<0.05).结论压力超负荷时CaMKⅣ激活,同时核转录因子CREB磷酸化增加,并引起细胞核内早期基因c-fos表达增加,可能在介导心肌肥厚发生中起重要作用.
文摘目的:探讨死亡相关蛋白激酶(death-associated protein kinase,DAPK)基因高甲基化与胃癌的发生以及临床病理特征之间的联系。方法:采用甲基化特异性聚合酶链反应(methylation-specific PCR,MSP)法分别检测66例胃癌患者的肿瘤组织、癌旁正常组织、手术前外周血浆以及37例术后血浆中DAPK基因启动子的甲基化状况,以20例健康人的外周血浆和胃镜活检正常胃组织作为对照。结果:胃癌组织中有66.7%(44/66)存在DAPK基因的异常甲基化,显著高于相应的癌旁正常组织[10.6%(7/66)],差异有统计学意义(P<0.001)。术前外周血浆中DAPK基因甲基化阳性率为16.7%(11/66);37例同时有胃癌根治术前后血浆标本的患者中,5例术前血浆甲基化阳性,术后全部转阴。而20例健康人的外周血浆和胃镜活检组织中均未检测到该基因甲基化。结论:DAPK基因在胃癌患者肿瘤组织和外周血浆中的高甲基化可能为胃癌的诊断以及临床预后评估提供有益的线索,手术后血浆中DAPK甲基化状态的变化可能与手术治疗有关。
