The Na^+/Ca^(2+) exchanger(NCX) protein family is a part of the cation/Ca^(2+) exchanger superfamily and participates in the regulation of cellular Ca^(2+) homeostasis. NCX1, the most important subtype in the NCX fami...The Na^+/Ca^(2+) exchanger(NCX) protein family is a part of the cation/Ca^(2+) exchanger superfamily and participates in the regulation of cellular Ca^(2+) homeostasis. NCX1, the most important subtype in the NCX family, is expressed widely in various organs and tissues in mammals and plays an especially important role in the physiological and pathological processes of nerves and the cardiovascular system. In the past few years, the function of NCX1 in the digestive system has received increasing attention; NCX1 not only participates in the healing process of gastric ulcer and gastric mucosal injury but also mediates the development of digestive cancer, acute pancreatitis, and intestinal absorption.This review aims to explore the roles of NCX1 in digestive system physiology and pathophysiology in order to guide clinical treatments.展开更多
以细菌纤维素为原料,合成2-羟基-3-磺酸基丙基细菌纤维素醚,采用红外光谱仪对产物结构进行了分析,用正交设计法研究了2-羟基-3-磺酸基丙基细菌纤维素醚合成的最佳工艺条件。结果表明,在优化条件下合成的2-羟基-3-磺酸基丙基细菌纤维素...以细菌纤维素为原料,合成2-羟基-3-磺酸基丙基细菌纤维素醚,采用红外光谱仪对产物结构进行了分析,用正交设计法研究了2-羟基-3-磺酸基丙基细菌纤维素醚合成的最佳工艺条件。结果表明,在优化条件下合成的2-羟基-3-磺酸基丙基细菌纤维素醚交换容量为0.481 mm ol/g。展开更多
Powered by the mitochondrial membrane potential,Ca2+ permeates the mitochondria via a Ca2+ channel termed Ca2+ uniporter and is pumped out by a Na+/Ca2+ exchanger,both of which are located on the inner mitochondrial m...Powered by the mitochondrial membrane potential,Ca2+ permeates the mitochondria via a Ca2+ channel termed Ca2+ uniporter and is pumped out by a Na+/Ca2+ exchanger,both of which are located on the inner mitochondrial membrane.Mitochondrial Ca2+ transients are critical for metabolic activity and regulating global Ca2+ responses.On the other hand,failure to control mitochondrial Ca2+ is a hallmark of ischemic and neurodegenerative diseases.Despite their importance,identifying the uniporter and exchanger remains elusive and their inhibitors are non-specific.This review will focus on the mitochondrial exchanger,initially describing how it was molecularly identified and linked to a novel member of the Na+/Ca2+ exchanger superfamily termed NCLX.Molecular control of NCLX expression provides a selective tool to determine its physiological role in a variety of cell types.In lymphocytes,NCLX is essential for refilling the endoplasmic reticulum Ca2+ stores required for antigen-dependent signaling.Communication of NCLX with the store-operated channel in astroglia controls Ca2+ influx and thereby neuro-transmitter release and cell proliferation.The refilling of the Ca2+ stores in the sarcoplasmic reticulum,which is controlled by NCLX,determines the frequency of action potential and Ca2+ transients in cardiomyocytes.NCLX is emerging as a hub for integrating glucose-dependent Na+ and Ca2+ signaling in pancreatic β cells,and the specific molecular control of NCLX expression resolved the controversy regarding its role in neurons and β cells.Future studies on an NCLX knockdown mouse model and identification of human NCLX mutations are expected to determine the role of mitochondrial Ca2+ efflux in organ activity and whether NCLX inactivation is linked to ischemic and/or neurodegenerative syndromes.Structure-function analysis and protein analysis will identify the NCLX mode of regulation and its partners in the inner membrane of the mitochondria.展开更多
Background： Na^＋/Ca^2＋ exchanger （NCX） plays a crucial role in pentylenetetrazol-induced convulsion. However, it is unclear whether NCX is critically involved in hyperthermia-induced convulsion. In this study, we...Background： Na^＋/Ca^2＋ exchanger （NCX） plays a crucial role in pentylenetetrazol-induced convulsion. However, it is unclear whether NCX is critically involved in hyperthermia-induced convulsion. In this study, we examined the potential changes in NCX3 in the hippocampus and cerebrocortex of rats with hyperthermia-induced convulsion. Methods： Twenty-one Sprague Dawley rats were randomly assigned to control group, convulsion-prone group and convulsion-resistant group （n = 7 in each group）. Whole-cell patch-clamp method was used to record NCX currents. Both the Western blotting analysis and immunofluorescence labeling techniques were used to examine the expression of NCX3. Results： NCX currents were decreased in rats after febrile convulsion. Compared to the control group, NCX3 expression was decreased by about 40% and 50% in the hippocampus and cerebrocortex of convulsion-prone rats, respectively. Furthermore, the extent of reduction in NCX3 expression seemed to correlate with the number of seizures. Conclusions： There is a significant reduction in NCX3 expression in rats with febrile convulsions. Our findings also indicate a potential link between NCX3 expression, febrile convulsion in early childhood, and adult onset of epilepsy.展开更多
Background：Calcium regulatory proteins-L-type Ca^2＋ channels （LTCCs）,ryanodine receptor 2 （RyR2）,and Na^＋/Ca^2＋ exchanger isoform 1 （NCX1） have been recognized as important protective mechanisms during myoca...Background：Calcium regulatory proteins-L-type Ca^2＋ channels （LTCCs）,ryanodine receptor 2 （RyR2）,and Na^＋/Ca^2＋ exchanger isoform 1 （NCX1） have been recognized as important protective mechanisms during myocardial ischemia-reperfusion injury （I/RI）.Both sevofturane postconditioning （SevoPoC） and delayed remote ischemic preconditioning （DRIPC） have been shown to protect the heart against I/RI.In this study,we aimed to compare the effects of SevoPoC and DRIPC on the expression of the three calcium regulatory proteins in an isolated rat heart model.Methods：After 30-min balanced perfusion,isolated hearts from rats were subjected to 30-min ischemia followed by 60-min reperfusion.Totally 40 isolated hearts were randomly assigned to four groups （n =10/group）：time control group,I/RI group,SevoPoC group,and DRIPC group.The effect of SevoPoC （3% v/v） and DRIPC were observed.Myocardial infarct size （IS）,cardiac troponin I level,and heart function were measured.The protein and messenger RNA levels of LTCCs,RyR2,and NCX1 were determined.Results：Both SevoPoC and DRIPC improved the recovery of myocardial function,and reduced cardiac troponin Ⅰ release after I/RI.The decrease in IS was more significant in the SevoPoC group than that in the DRIPC group （16.50% ± 4.54% in the SevoPoC group [P =0.0006],and 22.34% ± 4.02% in the DRIPC group [P =0.0007] vs.35.00% ± 5.24% in the I/RI group,respectively）.SevoPoC,but not DRIPC significantly inhibited the activity of NCX 1 （0.59 ＋ 0.09 in the I/RI group vs.0.32 ± 0.16 in the SevoPoC group,P =0.006;vs.0.57 ± 0.14 in the DRIPC group,P =0.072）.No statistical significant differences were observed in the expression of LTCCs and RyR2 between SevoPoC and DRIPC.In addition,subsequent correlation analysis showed a significantly positive relationship between the cardiac troponin Ⅰ level and the protein expression ofNCX1 （r =0.505,P =0.023）.Conclusion：SevoPoC may be more effective in the cardioprotection than DRIPC partly due to the deactivation of NCX1.展开更多
基金Supported by the National Natural Science Foundation of China,No.816660412 to Xie R and No.81160265 to Xu JY
文摘The Na^+/Ca^(2+) exchanger(NCX) protein family is a part of the cation/Ca^(2+) exchanger superfamily and participates in the regulation of cellular Ca^(2+) homeostasis. NCX1, the most important subtype in the NCX family, is expressed widely in various organs and tissues in mammals and plays an especially important role in the physiological and pathological processes of nerves and the cardiovascular system. In the past few years, the function of NCX1 in the digestive system has received increasing attention; NCX1 not only participates in the healing process of gastric ulcer and gastric mucosal injury but also mediates the development of digestive cancer, acute pancreatitis, and intestinal absorption.This review aims to explore the roles of NCX1 in digestive system physiology and pathophysiology in order to guide clinical treatments.
文摘Powered by the mitochondrial membrane potential,Ca2+ permeates the mitochondria via a Ca2+ channel termed Ca2+ uniporter and is pumped out by a Na+/Ca2+ exchanger,both of which are located on the inner mitochondrial membrane.Mitochondrial Ca2+ transients are critical for metabolic activity and regulating global Ca2+ responses.On the other hand,failure to control mitochondrial Ca2+ is a hallmark of ischemic and neurodegenerative diseases.Despite their importance,identifying the uniporter and exchanger remains elusive and their inhibitors are non-specific.This review will focus on the mitochondrial exchanger,initially describing how it was molecularly identified and linked to a novel member of the Na+/Ca2+ exchanger superfamily termed NCLX.Molecular control of NCLX expression provides a selective tool to determine its physiological role in a variety of cell types.In lymphocytes,NCLX is essential for refilling the endoplasmic reticulum Ca2+ stores required for antigen-dependent signaling.Communication of NCLX with the store-operated channel in astroglia controls Ca2+ influx and thereby neuro-transmitter release and cell proliferation.The refilling of the Ca2+ stores in the sarcoplasmic reticulum,which is controlled by NCLX,determines the frequency of action potential and Ca2+ transients in cardiomyocytes.NCLX is emerging as a hub for integrating glucose-dependent Na+ and Ca2+ signaling in pancreatic β cells,and the specific molecular control of NCLX expression resolved the controversy regarding its role in neurons and β cells.Future studies on an NCLX knockdown mouse model and identification of human NCLX mutations are expected to determine the role of mitochondrial Ca2+ efflux in organ activity and whether NCLX inactivation is linked to ischemic and/or neurodegenerative syndromes.Structure-function analysis and protein analysis will identify the NCLX mode of regulation and its partners in the inner membrane of the mitochondria.
基金This study wassupported by grants from the Natural Science Foundation Project of Hubei Province （No. 2004ABA234）, Wuhan Morning Program Project （No. 200850731390）, and Project of Wuhan Clinical Medical Research Center in Children＇s Neural Disease （No. 2014-160）.
文摘Background： Na^＋/Ca^2＋ exchanger （NCX） plays a crucial role in pentylenetetrazol-induced convulsion. However, it is unclear whether NCX is critically involved in hyperthermia-induced convulsion. In this study, we examined the potential changes in NCX3 in the hippocampus and cerebrocortex of rats with hyperthermia-induced convulsion. Methods： Twenty-one Sprague Dawley rats were randomly assigned to control group, convulsion-prone group and convulsion-resistant group （n = 7 in each group）. Whole-cell patch-clamp method was used to record NCX currents. Both the Western blotting analysis and immunofluorescence labeling techniques were used to examine the expression of NCX3. Results： NCX currents were decreased in rats after febrile convulsion. Compared to the control group, NCX3 expression was decreased by about 40% and 50% in the hippocampus and cerebrocortex of convulsion-prone rats, respectively. Furthermore, the extent of reduction in NCX3 expression seemed to correlate with the number of seizures. Conclusions： There is a significant reduction in NCX3 expression in rats with febrile convulsions. Our findings also indicate a potential link between NCX3 expression, febrile convulsion in early childhood, and adult onset of epilepsy.
文摘Background：Calcium regulatory proteins-L-type Ca^2＋ channels （LTCCs）,ryanodine receptor 2 （RyR2）,and Na^＋/Ca^2＋ exchanger isoform 1 （NCX1） have been recognized as important protective mechanisms during myocardial ischemia-reperfusion injury （I/RI）.Both sevofturane postconditioning （SevoPoC） and delayed remote ischemic preconditioning （DRIPC） have been shown to protect the heart against I/RI.In this study,we aimed to compare the effects of SevoPoC and DRIPC on the expression of the three calcium regulatory proteins in an isolated rat heart model.Methods：After 30-min balanced perfusion,isolated hearts from rats were subjected to 30-min ischemia followed by 60-min reperfusion.Totally 40 isolated hearts were randomly assigned to four groups （n =10/group）：time control group,I/RI group,SevoPoC group,and DRIPC group.The effect of SevoPoC （3% v/v） and DRIPC were observed.Myocardial infarct size （IS）,cardiac troponin I level,and heart function were measured.The protein and messenger RNA levels of LTCCs,RyR2,and NCX1 were determined.Results：Both SevoPoC and DRIPC improved the recovery of myocardial function,and reduced cardiac troponin Ⅰ release after I/RI.The decrease in IS was more significant in the SevoPoC group than that in the DRIPC group （16.50% ± 4.54% in the SevoPoC group [P =0.0006],and 22.34% ± 4.02% in the DRIPC group [P =0.0007] vs.35.00% ± 5.24% in the I/RI group,respectively）.SevoPoC,but not DRIPC significantly inhibited the activity of NCX 1 （0.59 ＋ 0.09 in the I/RI group vs.0.32 ± 0.16 in the SevoPoC group,P =0.006;vs.0.57 ± 0.14 in the DRIPC group,P =0.072）.No statistical significant differences were observed in the expression of LTCCs and RyR2 between SevoPoC and DRIPC.In addition,subsequent correlation analysis showed a significantly positive relationship between the cardiac troponin Ⅰ level and the protein expression ofNCX1 （r =0.505,P =0.023）.Conclusion：SevoPoC may be more effective in the cardioprotection than DRIPC partly due to the deactivation of NCX1.
