By screening tobacco cDNA library with MCK1 as a probe, we isolated a cDNA clone NtCPK5 （accession number AY971376）, which encodes a typical calcium-dependent protein kinase. Sequence analyses indicated that NtCPK5 ...By screening tobacco cDNA library with MCK1 as a probe, we isolated a cDNA clone NtCPK5 （accession number AY971376）, which encodes a typical calcium-dependent protein kinase. Sequence analyses indicated that NtCPK5 is related to both CPKs and CRKs superfamilies and has all of the three conserved domains of CPKs. The biochemical activity of NtCPK5 was calcium-dependent. NtCPK5 had Vmax and Km of 526nmol/min/mg and 210μg/ml respectively with calf thymus histone （fraction Ⅲ, abbreviated to histone Ⅲs） as substrate. For substrate syntide-2, NtCPK5 showed a higher Vmax of 2008 nmol/min/mg and a lower Km of 30μM. The K0.5 of calcium activation was 0.04μM or 0.06μM for histone Ⅲs or syntide-2 respectively. The putative myristoylation and palmitoylation consensus sequence of NtCPK5 suggests that it could be a membrane-anchoring protein. Indeed, our transient expression experiments with wild type and mutant forms of NtCPK5/GFP fusion proteins showed that NtCPK5 was localized to the plasma membrane of onion epidermal cells and that the localization required the N-terminal acylation sites of NtCPK5/GFP. Taking together, our data have demonstrated the biochemical characteristics of a novel protein NtCPK5 and its subcellular localization as a membrane-anchoring protein.展开更多
Background Cartilage oligomeric matrix protein （COMP） is mainly found in the skeletal system and vascular smooth muscle cells. Recent researches showed that it had a protective function on blood vessels and could al...Background Cartilage oligomeric matrix protein （COMP） is mainly found in the skeletal system and vascular smooth muscle cells. Recent researches showed that it had a protective function on blood vessels and could also inhibit vascular calcification. We investigated the serum COMPs in coronary heart disease （CHD） patients, and the relationship between serum COMP and the calcification of coronary artery. Methods A total of 233 consecutive chest pain patients who first underwent coronary angiography followed by multi-slice computed to- mography （MSCT） within six months were recruited and divided into two groups according to the coronary angiography luminal diameter narrowing percentages： CHD group （diameter narrowing 〉 50%, n = 194） and control group （diameter narrowing 〈 50%, n = 39）. The Gen- sini score, Syntax score and coronary artery calcium score （CACs） were calculated. The serum COMP level was determined using ELISA. Results The levels of COMP were significantly higher in the CHD group than in the control group 155.7 （124.5-194.5） ng/mL vs. 128.4 （113.0-159.9） ng/mL, P = 0.019. There were no correlation between COMP, Gensini score, Syntax score, severity of coronary stenosis and the number of coronary artery with stenosis 〉 50%. The serum COMP was correlated with age （r = 0.294, P 〈 0.001）, fasting glucose （r = 0.163, P = 0.015）, HbAlc （r = 0.194, P = 0.015） and CACs （r = 0.137, P = 0.037）. Stepwise linear regression analysis showed that COMP level and age were independent predictors of CACs in the CHD patients （fl = 0.402, t = 2.612, P = 0.015; fl = 0.472, t = 3.077, P = 0.005）. Performance of COMP for predicting CHD was shown as area under curve （AUC）： 0.632, 95% CI： 0.549-0.715 and upper tertile CACs was AUC： 0.602, 95% CI： 0.5264）.678 in receiver operating characteristic （ROC） curve analysis. Conclusion Calcification of coronary artery was an independent predictor of serum COMPs.展开更多
AIM： To examine the existence of Nitric oxide/ cGMP sensitive store-operated Ca^2＋ entry in mouse fibroblast NIH/3T3 cells and its influence on matrix metalloproteinase （MMP） production and adhesion ability of fib...AIM： To examine the existence of Nitric oxide/ cGMP sensitive store-operated Ca^2＋ entry in mouse fibroblast NIH/3T3 cells and its influence on matrix metalloproteinase （MMP） production and adhesion ability of fibroblasts. METHODS： NIH/3T3 cells were cultured. Confocal laser scanning microscopy was used to examine the existence of thapsigargin-induced store-operated Ca^2＋ entry in fibroblasts. Gelatin zymography and semiquantitative reverse transcriptase-polymerase chain reaction （RTPCR） were employed to detect the involvement of [Ca^2＋]i and NO/cGMP in MMP secretion. The involvement of NO/ cGMP-sensitive Ca^2＋ entry in adhesion was determined using matrigel-coated culture plates. RESULTS： 8-bromo-cGMP inhibited the thapsigargin-induced Ca^2＋ entry in 3T3 cells. The cGMP-induced inhibition was abolished by an inhibitor of protein kinase G, KT5823 （1μmol/L）. A similar effect on the Ca^2＋ entry was observed in 3T3 cells in response to a NO donor, （±）-S-nitroso-N-acetylpenicillamine （SNAP）. The inhibitory effect of SNAP on the thapsigargin-induced Ca^2＋ entry was also observed, indicating NO/cGMP-regulated Ca^2＋ entry in 3T3 cells. Results of gelatin zymography assay showed that addition of extracellular Ca^2＋ concentration induced MMP release and activation in a dose-dependent manner. RT-PCR also showed that cGMP and SNAP reduced the production of MMP mRNA in 3T3 cells. Experiments investigating adhesion potentials demonstrated that cGMP and SNAP could upgrade 3T3 cell attachment rate to the matrigel-coated culture plates.CONCLUSION： NO/cGMP sensitive store-operated Ca^2＋ entry occurs in fibroblasts, and attenuates their adhesion potentials through its influence on MMP secretion.展开更多
Background Circulating microparticles （MPs） have been reported to be associated with coronary artery disease （CAD）. In this study, we explored the relationship between MPs procoagulant activity and characteristics...Background Circulating microparticles （MPs） have been reported to be associated with coronary artery disease （CAD）. In this study, we explored the relationship between MPs procoagulant activity and characteristics of atherosclerotic plaque detected by 64-slice computed tomography angiography （CTA）. Methods In 127 consecutive patients with CAD but without acute coronary syndrome and who under went 64-slice CTA, MPs procoagulant activity in plasma Coy a thrombin generation test）, soluble form of lectin-like oxidized low-density lipoprotein receptor-1 （sLOX-1） and N（epsilon）-（carboxymethyl） lysine （CML） circulating levels （by ELISA） were measured. A quantitative volumetric analysis of the lumen and plaque burden of the vessel wall （soft and calcific components）, for the three major coronary vessels, was performed. The patients were classified in three groups according to the presence of calcium volume： non-calcified plaque （NCP） group （calcium volume （%） = 0）, moderate calcified plaque （MCP） group （0 〈 calcium volume （%） 〈 1）, and calcified plaque （CP） group （calcium volume （%） 〉 1）. Results MPs procoagulant activity and CML levels were higher in MCP group than in CP or NCP group （P = 0.009 and P = 0.027, respectively）. MPs procoagulant activity was positively associated with CML （r = 0.317, P 〈 0.0001） and sLOX-1 levels （r = 0.216, P = 0.0025）. Conclusions MPs procoagulant activity was higher in the MCP patient group and correlated positively with sLOX-1 and CML levels, suggesting that it may characterize a state of blood vulnerability that may locally precipitate plaque instability and increase the risk of subsequent major cardiovascular events.展开更多
Objective: To study the role of calpain in the mechanism of oxidative cataract through detecting the level of intracellular free Ca2+, the expression and proteolytic activity of calpain in the lens epithelial cells (...Objective: To study the role of calpain in the mechanism of oxidative cataract through detecting the level of intracellular free Ca2+, the expression and proteolytic activity of calpain in the lens epithelial cells (LECs) of H2O2-induced cataract. Methods: Rat lenses were cultured in vitro and cataract was induced by H2O2. The level of intracellular free Ca2+ was measured by fluorescence determination with fura-2/AM. The expression of m-calpain protein in LECs was detected with immunohistochemical method. The proteolytic activity in LECs was measured using a fluorogenic synthetic substrate. Results: There were significant differences of the level of intracellular free Ca2+ (P=0.001, 0.000, 0.000), the expression of m-calpain (P=0.001, 0.000, 0.000) and the proteolytic activity of calpain (P=0.001, 0.000, 0.000) between H2O2-induced and control group at 6, 12 and 24 h, respectively. Conclusions: H2O2 can increase intracellular free Ca2+, then enhance the expression and proteolytic activity of calpain which may play a role in the mechanism of oxidative cataract of rat.展开更多
Extrathoracic solitary fibrous tumors(SFTs) have been described at almost every anatomic location of human body,but reports of SFT in the abdominal cavity are rare.We herein present a rare case of SFT originating from...Extrathoracic solitary fibrous tumors(SFTs) have been described at almost every anatomic location of human body,but reports of SFT in the abdominal cavity are rare.We herein present a rare case of SFT originating from greater omentum.Computed tomography revealed a 15.8 cm × 21.0 cm solid mass located at superior aspect of stomach.Open laparotomy confirmed its mesenchymal origin.Microscopically,its tissue was composed of non-organized and spindle-shaped cells exhibiting atypical nuclei,which were divided up by branching vessel and collagen bundles.Immunohistochemical staining showed that this tumor was negative for CD117,CD99,CD68,cytokeratin,calretinin,desmin,epithelial membrane antigen,F8 and S-100,but positive for CD34,bcl-2,α-smooth muscle actin and vimentin.The patient presented no evidence of recurrence during follow-up.SFT arising from abdominal cavity can be diagnosed by histological findings and immunohistochemical markers,especially for CD34 and bcl-2 positive cases.展开更多
[Objective] This study aimed to investigate the acaricidal lffect of scopo- letin, and provide the biochemical evidences of scopoletin influencus Ca2＋-ATPase activity and gene expressions in the Carmine Spider Mite, ...[Objective] This study aimed to investigate the acaricidal lffect of scopo- letin, and provide the biochemical evidences of scopoletin influencus Ca2＋-ATPase activity and gene expressions in the Carmine Spider Mite, Tetranych＇us cinnabarinus. in increased protein contents; kinetic analysis showed that the catalytic capability of Ca2＋-ATPase was significantly reduced by scopoletin. [Conclusion] Scopoletin exhibits a significant inhibitory effect on Ca2＋-ATPase, and its acaricidal effect against T. cinnabarinus might be due to the direct inhibition of Ca2＋-ATPase.展开更多
P48 is a cytokine which induces monocyte differentia-tion and the induction of cytotoxic activity. In this study,the signal transduction events involved in the stimulation of monocytes with the membrane form of P48 (m...P48 is a cytokine which induces monocyte differentia-tion and the induction of cytotoxic activity. In this study,the signal transduction events involved in the stimulation of monocytes with the membrane form of P48 (mP48) were investigated. Monocyte stimulation with mP48 was found to involve the mobilization of intracellular calcium (Ca2+)and the activation and translocation of PKC from the cy-tosol to the membrane. Membane P48 induced a rapid rise of intracellular Ca2+ in a dose dependent maner. Simi-larly the stimulation of monocytes with P48 was found to involve the activation and translocation of PKC. The translocation of PKC was rapid (within 0-5 min) yet tran-sient with PKC activity returning to control levels by 8 min. The functional role of protein kineses in P48 induced TNF secretion was studied using various kinese inhibitors. The PKC inhibitors, H-7 and sphingosine, were found to inhibit P48 induced TNF secretion with 50% inhibition at 5μM HA1004, which inhibts cyclic nucleotide-dependent kinase (PKA, Ki 1.2μM), did not inhibit TNF secretion. H-8 (PKA inhibitor) was found to be an effective inhibitor of TNF secretion only at high concentrations(30μp. The Calmodulin-dependent kinase inhibitor, W7 (Ki 12μM)was found to be effective at concentration above 5μM.These findings suggest that P48-triggered TNF secretion involves transmembrane Ca2+ signaling and the subse-quent activation of at least two protein kineses, PKC and CaMK.展开更多
We investigated the developmental expression pattern of AmphiCaM in cephalochordate amphioxus （Branchiostoma belcheri tsingtauense）. We cultured and sampled the animals at different developmental stages （eggs and l...We investigated the developmental expression pattern of AmphiCaM in cephalochordate amphioxus （Branchiostoma belcheri tsingtauense）. We cultured and sampled the animals at different developmental stages （eggs and larvae）, and used in-situ hybridization and northern blotting to document the spatial and temporal changes in AmphiCaM expression. The alimentary tract dominates the development from the late neurula stage to the adult stage. AmphiCaM expression increased significantly in the alimentary tract during the late neurula stage and remained elevated in the adults. Our results indicate that AmphiCaM is involved in the differentiation of the alimentary tract in amphioxus; and furthermore, provide an insight into the change in function of CaM genes during evolution.展开更多
基金supported in part by the National Natural Science Foundation of China(Grant No.30230050)the Program for Changjiang Scholars and Innovative Research Team in University to Ying Tang LU.
文摘By screening tobacco cDNA library with MCK1 as a probe, we isolated a cDNA clone NtCPK5 （accession number AY971376）, which encodes a typical calcium-dependent protein kinase. Sequence analyses indicated that NtCPK5 is related to both CPKs and CRKs superfamilies and has all of the three conserved domains of CPKs. The biochemical activity of NtCPK5 was calcium-dependent. NtCPK5 had Vmax and Km of 526nmol/min/mg and 210μg/ml respectively with calf thymus histone （fraction Ⅲ, abbreviated to histone Ⅲs） as substrate. For substrate syntide-2, NtCPK5 showed a higher Vmax of 2008 nmol/min/mg and a lower Km of 30μM. The K0.5 of calcium activation was 0.04μM or 0.06μM for histone Ⅲs or syntide-2 respectively. The putative myristoylation and palmitoylation consensus sequence of NtCPK5 suggests that it could be a membrane-anchoring protein. Indeed, our transient expression experiments with wild type and mutant forms of NtCPK5/GFP fusion proteins showed that NtCPK5 was localized to the plasma membrane of onion epidermal cells and that the localization required the N-terminal acylation sites of NtCPK5/GFP. Taking together, our data have demonstrated the biochemical characteristics of a novel protein NtCPK5 and its subcellular localization as a membrane-anchoring protein.
文摘Background Cartilage oligomeric matrix protein （COMP） is mainly found in the skeletal system and vascular smooth muscle cells. Recent researches showed that it had a protective function on blood vessels and could also inhibit vascular calcification. We investigated the serum COMPs in coronary heart disease （CHD） patients, and the relationship between serum COMP and the calcification of coronary artery. Methods A total of 233 consecutive chest pain patients who first underwent coronary angiography followed by multi-slice computed to- mography （MSCT） within six months were recruited and divided into two groups according to the coronary angiography luminal diameter narrowing percentages： CHD group （diameter narrowing 〉 50%, n = 194） and control group （diameter narrowing 〈 50%, n = 39）. The Gen- sini score, Syntax score and coronary artery calcium score （CACs） were calculated. The serum COMP level was determined using ELISA. Results The levels of COMP were significantly higher in the CHD group than in the control group 155.7 （124.5-194.5） ng/mL vs. 128.4 （113.0-159.9） ng/mL, P = 0.019. There were no correlation between COMP, Gensini score, Syntax score, severity of coronary stenosis and the number of coronary artery with stenosis 〉 50%. The serum COMP was correlated with age （r = 0.294, P 〈 0.001）, fasting glucose （r = 0.163, P = 0.015）, HbAlc （r = 0.194, P = 0.015） and CACs （r = 0.137, P = 0.037）. Stepwise linear regression analysis showed that COMP level and age were independent predictors of CACs in the CHD patients （fl = 0.402, t = 2.612, P = 0.015; fl = 0.472, t = 3.077, P = 0.005）. Performance of COMP for predicting CHD was shown as area under curve （AUC）： 0.632, 95% CI： 0.549-0.715 and upper tertile CACs was AUC： 0.602, 95% CI： 0.5264）.678 in receiver operating characteristic （ROC） curve analysis. Conclusion Calcification of coronary artery was an independent predictor of serum COMPs.
基金Supported by the Major State Basic Research Development Program (973 Program) of China, No.2003CB515507
文摘AIM： To examine the existence of Nitric oxide/ cGMP sensitive store-operated Ca^2＋ entry in mouse fibroblast NIH/3T3 cells and its influence on matrix metalloproteinase （MMP） production and adhesion ability of fibroblasts. METHODS： NIH/3T3 cells were cultured. Confocal laser scanning microscopy was used to examine the existence of thapsigargin-induced store-operated Ca^2＋ entry in fibroblasts. Gelatin zymography and semiquantitative reverse transcriptase-polymerase chain reaction （RTPCR） were employed to detect the involvement of [Ca^2＋]i and NO/cGMP in MMP secretion. The involvement of NO/ cGMP-sensitive Ca^2＋ entry in adhesion was determined using matrigel-coated culture plates. RESULTS： 8-bromo-cGMP inhibited the thapsigargin-induced Ca^2＋ entry in 3T3 cells. The cGMP-induced inhibition was abolished by an inhibitor of protein kinase G, KT5823 （1μmol/L）. A similar effect on the Ca^2＋ entry was observed in 3T3 cells in response to a NO donor, （±）-S-nitroso-N-acetylpenicillamine （SNAP）. The inhibitory effect of SNAP on the thapsigargin-induced Ca^2＋ entry was also observed, indicating NO/cGMP-regulated Ca^2＋ entry in 3T3 cells. Results of gelatin zymography assay showed that addition of extracellular Ca^2＋ concentration induced MMP release and activation in a dose-dependent manner. RT-PCR also showed that cGMP and SNAP reduced the production of MMP mRNA in 3T3 cells. Experiments investigating adhesion potentials demonstrated that cGMP and SNAP could upgrade 3T3 cell attachment rate to the matrigel-coated culture plates.CONCLUSION： NO/cGMP sensitive store-operated Ca^2＋ entry occurs in fibroblasts, and attenuates their adhesion potentials through its influence on MMP secretion.
文摘Background Circulating microparticles （MPs） have been reported to be associated with coronary artery disease （CAD）. In this study, we explored the relationship between MPs procoagulant activity and characteristics of atherosclerotic plaque detected by 64-slice computed tomography angiography （CTA）. Methods In 127 consecutive patients with CAD but without acute coronary syndrome and who under went 64-slice CTA, MPs procoagulant activity in plasma Coy a thrombin generation test）, soluble form of lectin-like oxidized low-density lipoprotein receptor-1 （sLOX-1） and N（epsilon）-（carboxymethyl） lysine （CML） circulating levels （by ELISA） were measured. A quantitative volumetric analysis of the lumen and plaque burden of the vessel wall （soft and calcific components）, for the three major coronary vessels, was performed. The patients were classified in three groups according to the presence of calcium volume： non-calcified plaque （NCP） group （calcium volume （%） = 0）, moderate calcified plaque （MCP） group （0 〈 calcium volume （%） 〈 1）, and calcified plaque （CP） group （calcium volume （%） 〉 1）. Results MPs procoagulant activity and CML levels were higher in MCP group than in CP or NCP group （P = 0.009 and P = 0.027, respectively）. MPs procoagulant activity was positively associated with CML （r = 0.317, P 〈 0.0001） and sLOX-1 levels （r = 0.216, P = 0.0025）. Conclusions MPs procoagulant activity was higher in the MCP patient group and correlated positively with sLOX-1 and CML levels, suggesting that it may characterize a state of blood vulnerability that may locally precipitate plaque instability and increase the risk of subsequent major cardiovascular events.
文摘Objective: To study the role of calpain in the mechanism of oxidative cataract through detecting the level of intracellular free Ca2+, the expression and proteolytic activity of calpain in the lens epithelial cells (LECs) of H2O2-induced cataract. Methods: Rat lenses were cultured in vitro and cataract was induced by H2O2. The level of intracellular free Ca2+ was measured by fluorescence determination with fura-2/AM. The expression of m-calpain protein in LECs was detected with immunohistochemical method. The proteolytic activity in LECs was measured using a fluorogenic synthetic substrate. Results: There were significant differences of the level of intracellular free Ca2+ (P=0.001, 0.000, 0.000), the expression of m-calpain (P=0.001, 0.000, 0.000) and the proteolytic activity of calpain (P=0.001, 0.000, 0.000) between H2O2-induced and control group at 6, 12 and 24 h, respectively. Conclusions: H2O2 can increase intracellular free Ca2+, then enhance the expression and proteolytic activity of calpain which may play a role in the mechanism of oxidative cataract of rat.
文摘Extrathoracic solitary fibrous tumors(SFTs) have been described at almost every anatomic location of human body,but reports of SFT in the abdominal cavity are rare.We herein present a rare case of SFT originating from greater omentum.Computed tomography revealed a 15.8 cm × 21.0 cm solid mass located at superior aspect of stomach.Open laparotomy confirmed its mesenchymal origin.Microscopically,its tissue was composed of non-organized and spindle-shaped cells exhibiting atypical nuclei,which were divided up by branching vessel and collagen bundles.Immunohistochemical staining showed that this tumor was negative for CD117,CD99,CD68,cytokeratin,calretinin,desmin,epithelial membrane antigen,F8 and S-100,but positive for CD34,bcl-2,α-smooth muscle actin and vimentin.The patient presented no evidence of recurrence during follow-up.SFT arising from abdominal cavity can be diagnosed by histological findings and immunohistochemical markers,especially for CD34 and bcl-2 positive cases.
基金Supported by National Natural Science Foundation of China(31272058)Specialized Research Fund for the Doctoral Program of Higher Education(20100182120021)
文摘[Objective] This study aimed to investigate the acaricidal lffect of scopo- letin, and provide the biochemical evidences of scopoletin influencus Ca2＋-ATPase activity and gene expressions in the Carmine Spider Mite, Tetranych＇us cinnabarinus. in increased protein contents; kinetic analysis showed that the catalytic capability of Ca2＋-ATPase was significantly reduced by scopoletin. [Conclusion] Scopoletin exhibits a significant inhibitory effect on Ca2＋-ATPase, and its acaricidal effect against T. cinnabarinus might be due to the direct inhibition of Ca2＋-ATPase.
文摘P48 is a cytokine which induces monocyte differentia-tion and the induction of cytotoxic activity. In this study,the signal transduction events involved in the stimulation of monocytes with the membrane form of P48 (mP48) were investigated. Monocyte stimulation with mP48 was found to involve the mobilization of intracellular calcium (Ca2+)and the activation and translocation of PKC from the cy-tosol to the membrane. Membane P48 induced a rapid rise of intracellular Ca2+ in a dose dependent maner. Simi-larly the stimulation of monocytes with P48 was found to involve the activation and translocation of PKC. The translocation of PKC was rapid (within 0-5 min) yet tran-sient with PKC activity returning to control levels by 8 min. The functional role of protein kineses in P48 induced TNF secretion was studied using various kinese inhibitors. The PKC inhibitors, H-7 and sphingosine, were found to inhibit P48 induced TNF secretion with 50% inhibition at 5μM HA1004, which inhibts cyclic nucleotide-dependent kinase (PKA, Ki 1.2μM), did not inhibit TNF secretion. H-8 (PKA inhibitor) was found to be an effective inhibitor of TNF secretion only at high concentrations(30μp. The Calmodulin-dependent kinase inhibitor, W7 (Ki 12μM)was found to be effective at concentration above 5μM.These findings suggest that P48-triggered TNF secretion involves transmembrane Ca2+ signaling and the subse-quent activation of at least two protein kineses, PKC and CaMK.
基金Supported in part by Shandong Entry-Exit Inspection and Quarantine Bureau （SK200807） We thank Dr. LI Xiangning, who works in the CSR （Center for Scientific Review） of NIH （National Institutes of Health）, USA, for his critical reading of the manuscript.
文摘We investigated the developmental expression pattern of AmphiCaM in cephalochordate amphioxus （Branchiostoma belcheri tsingtauense）. We cultured and sampled the animals at different developmental stages （eggs and larvae）, and used in-situ hybridization and northern blotting to document the spatial and temporal changes in AmphiCaM expression. The alimentary tract dominates the development from the late neurula stage to the adult stage. AmphiCaM expression increased significantly in the alimentary tract during the late neurula stage and remained elevated in the adults. Our results indicate that AmphiCaM is involved in the differentiation of the alimentary tract in amphioxus; and furthermore, provide an insight into the change in function of CaM genes during evolution.
