Purpose: Large conductance, voltage- and Ca2+-activated K+ (BK) channel is thought to have a central role to regulate urinary bladder smooth muscle functions, and its dysfunction may lead to increase of urination freq...Purpose: Large conductance, voltage- and Ca2+-activated K+ (BK) channel is thought to have a central role to regulate urinary bladder smooth muscle functions, and its dysfunction may lead to increase of urination frequency and overactive bladder. The present study aims to investigate the expression pattern of BK channel subunits in the human urinary bladder, and how it changes in association with bladder outlet obstruction (BOO). Materials and Methods: Human bladders were obtained from 7 controls without prostatic enlargement and lower urinary tract symptoms and 4 BPH patients with clinically diagnosed overactive bladder who were verified by the International Prostate Symptom Score (IPSS) and prostate volume. The expression and location of BK channel protein complex was examined using immunohistochemistry with affinity-purified anti-BKα antibodies. A real-time RT-PCR was used to quantify the expression of each BK channel subunit (α and β1 - 4) gene in the mucosal and muscle layers of human urinary bladder. Results: Immunohistochemical staining for BK-α protein complex was localized in the muscle and submucosal regions of urinary bladder. RT-PCR analysis revealed the presence of α-, β1-, and β4-subunit genes of BK channel in the mucosal layer, α- and β1-subunit in the muscle layer. The expressions of α- and β1-subunit genes in the muscle (α: p = 0.0003, β1: p = 0.0003) and mucosal (α: p = 0.03, β1: p = 0.02) layers significantly decreased in BOO bladders compared with controls. The expression levels of α- and β1-subunit in mucosal layer were statistically correlated with storage score of IPSS (α;r = 0.84, p = 0.002, β1;r = 0.84, p = 0.002), and so were in muscle layer (α;r = 0.934, p 0.0001, β1;r = 0.917, p = 0.00018). Conclusions: BK channels, which are mainly composed of α- and β1-subunits, are expressed in both the mucosal and muscle layers of human urinary bladder. Decreased expression of BK channel in BOO might be implicated in the mechanisms underlying the development of overactive bladder.展开更多
Dravet syndrome is a rare epileptic encephalopathy characterized by frequent seizures beginning in the first year of life and behavioral disorders. Mutations in the sodium channel α1 subunit gene are the main cause o...Dravet syndrome is a rare epileptic encephalopathy characterized by frequent seizures beginning in the first year of life and behavioral disorders. Mutations in the sodium channel α1 subunit gene are the main cause of this disease. We report two patients with refractory seizures and psychomotor retardation in whom the final diagnosis was Dravet syndrome with confirmed mutations in the sodium channel α1 subunit gene. The mutation identified in the second patient was a novel frame shift mutation, which resulted from the deletion of five nucleotides in exon 24.展开更多
[Objectives] To study the effects of Tiaomaiyin and its disassembled prescription on expression of L-type calcium channel β2 subunit in rat model of tachyarrhythmia. [Methods] Sixty Wistar rats were randomly divided ...[Objectives] To study the effects of Tiaomaiyin and its disassembled prescription on expression of L-type calcium channel β2 subunit in rat model of tachyarrhythmia. [Methods] Sixty Wistar rats were randomly divided into model group,Tiaomaiyin prescription group( whole prescription group),main efficacy group of removing heat to cool blood( blood cooling group),and auxiliary drug efficacy group of benefiting qi and nourishing heart( qi benefiting group),auxiliary efficacy group of promoting flow of qi and blood circulation( qi flow promoting group),and amiodarone group( western medicine group). Aconitine was given 7 d after the intragastric administration of the corresponding drugs,and the time of occurrence of arrhythmia in each group was observed. The left ventricular myocardium was subjected to reverse transcription-polymerase chain reaction and Western blotting. [Results] The ventricular premature beats( VPB) time in the whole prescription group and western medicine group was significantly longer than that in the model group. Ventricular tachycardia( VT),ventricular fibrillation( VF),and cardiac arrest( CA) were longer in the whole prescription group,blood cooling group,and western medicine group. The mRNA and protein expression of L-type calcium channel β2 subunit in the whole prescription group,blood cooling group and western medicine group were significantly decreased. [Conclusions] Tiaomaiyin whole prescription group and blood cooling group can reduce the occurrence time of tachyarrhythmia and reduce the expression of LTCC β2 in myocardium.展开更多
BK channels are widely expressed in both excitable and non-excitable cells and known to be involved in many physiological processes,such as vascular smooth tone regulation,neuronal firing and endocrine cell secretion[...BK channels are widely expressed in both excitable and non-excitable cells and known to be involved in many physiological processes,such as vascular smooth tone regulation,neuronal firing and endocrine cell secretion[1].Recently, the BK channels have展开更多
Aim Large conductance Ca2^＋ -activated potassium channel （BK） , expressed in the distal nephron, me- diates potassium secretion. Loss-of-function of renal BK channel is closely related with aldosteronism resulting ...Aim Large conductance Ca2^＋ -activated potassium channel （BK） , expressed in the distal nephron, me- diates potassium secretion. Loss-of-function of renal BK channel is closely related with aldosteronism resulting from renal potassium retention and hyperkalemia. Natural products affecting BK functions are still scarce, especially ac- tivators. Here, the pharmacological characterization of curcumin, one of the compounds isolated from the herb Cur- cuma longa. , on B K channels have been investigated. Methods B K currents were recorded by whole-cell patch- clamp, mRNA expressions of BK were measured by quantitative real-time PCR. The surface and total protein ex- pressions of B K were assessed by surface biotinylation and Western blot. Functional study was performed on aortic rings. Results Curcumin potently increased B K currents in transfected HEK293 cells as well as the current densi- ty in A7r5 cells （ endogenous expressed BK （ α ＋ β1） channels） with ECs0 - （6.76 ± 2.24） μmol · L^-1 and （7.19 ± 0.07） μmol · L^-1, respectively. Curcumin up-regulated B K protein abundance without affecting its mR- NA expression in A7r5 cells. Surface expression and half-life of B K channels were increased by curcumin in HEK293 cells, which were abolished by MG-132, a proteasome inhibitor. Simultaneously, ERK 1/2 phosphoryla- tion was also increased by curcumin. U0126, an inhibitor of ERK, attenuate the curcumin-induced up-regulation of BK protein level. Curcumin-induced relaxation in isolated rat aortic rings was significantly attenuated by paxilline, a BK channel specific blocker. Conclusion Curcumin increased BK currents and protein abundance by inhibiting proteasomal degradation and activating ERK signaling pathway. These findings suggest that curcumin is a potential BK channel activator and provide novel insight into its complicated pharmacological effects and mechanisms.展开更多
文摘Purpose: Large conductance, voltage- and Ca2+-activated K+ (BK) channel is thought to have a central role to regulate urinary bladder smooth muscle functions, and its dysfunction may lead to increase of urination frequency and overactive bladder. The present study aims to investigate the expression pattern of BK channel subunits in the human urinary bladder, and how it changes in association with bladder outlet obstruction (BOO). Materials and Methods: Human bladders were obtained from 7 controls without prostatic enlargement and lower urinary tract symptoms and 4 BPH patients with clinically diagnosed overactive bladder who were verified by the International Prostate Symptom Score (IPSS) and prostate volume. The expression and location of BK channel protein complex was examined using immunohistochemistry with affinity-purified anti-BKα antibodies. A real-time RT-PCR was used to quantify the expression of each BK channel subunit (α and β1 - 4) gene in the mucosal and muscle layers of human urinary bladder. Results: Immunohistochemical staining for BK-α protein complex was localized in the muscle and submucosal regions of urinary bladder. RT-PCR analysis revealed the presence of α-, β1-, and β4-subunit genes of BK channel in the mucosal layer, α- and β1-subunit in the muscle layer. The expressions of α- and β1-subunit genes in the muscle (α: p = 0.0003, β1: p = 0.0003) and mucosal (α: p = 0.03, β1: p = 0.02) layers significantly decreased in BOO bladders compared with controls. The expression levels of α- and β1-subunit in mucosal layer were statistically correlated with storage score of IPSS (α;r = 0.84, p = 0.002, β1;r = 0.84, p = 0.002), and so were in muscle layer (α;r = 0.934, p 0.0001, β1;r = 0.917, p = 0.00018). Conclusions: BK channels, which are mainly composed of α- and β1-subunits, are expressed in both the mucosal and muscle layers of human urinary bladder. Decreased expression of BK channel in BOO might be implicated in the mechanisms underlying the development of overactive bladder.
基金Acknowledgments We thank Ms Mekie Takahashi, Ms Ritsuko Kanda （Nagaya University, Japan）, Dr Changliang Fu and Dr Shouqing Lu （Institute of Mechanics, Chinese Academy of Sciences） for technical assistance. This work was partly supported by research grants from the National Natural Science Foundation of China （10602031） and Grants-in-aid for Scientific Research on Priority Areas （#15086270 to M.S.） and Creative Research （# 16GS0308 to M.S.） from the Ministry of Education Science Sports and Culture, Japan.
文摘Dravet syndrome is a rare epileptic encephalopathy characterized by frequent seizures beginning in the first year of life and behavioral disorders. Mutations in the sodium channel α1 subunit gene are the main cause of this disease. We report two patients with refractory seizures and psychomotor retardation in whom the final diagnosis was Dravet syndrome with confirmed mutations in the sodium channel α1 subunit gene. The mutation identified in the second patient was a novel frame shift mutation, which resulted from the deletion of five nucleotides in exon 24.
基金Supported by the Project of Beijing Municipal Natural Science Foundation(7173261)
文摘[Objectives] To study the effects of Tiaomaiyin and its disassembled prescription on expression of L-type calcium channel β2 subunit in rat model of tachyarrhythmia. [Methods] Sixty Wistar rats were randomly divided into model group,Tiaomaiyin prescription group( whole prescription group),main efficacy group of removing heat to cool blood( blood cooling group),and auxiliary drug efficacy group of benefiting qi and nourishing heart( qi benefiting group),auxiliary efficacy group of promoting flow of qi and blood circulation( qi flow promoting group),and amiodarone group( western medicine group). Aconitine was given 7 d after the intragastric administration of the corresponding drugs,and the time of occurrence of arrhythmia in each group was observed. The left ventricular myocardium was subjected to reverse transcription-polymerase chain reaction and Western blotting. [Results] The ventricular premature beats( VPB) time in the whole prescription group and western medicine group was significantly longer than that in the model group. Ventricular tachycardia( VT),ventricular fibrillation( VF),and cardiac arrest( CA) were longer in the whole prescription group,blood cooling group,and western medicine group. The mRNA and protein expression of L-type calcium channel β2 subunit in the whole prescription group,blood cooling group and western medicine group were significantly decreased. [Conclusions] Tiaomaiyin whole prescription group and blood cooling group can reduce the occurrence time of tachyarrhythmia and reduce the expression of LTCC β2 in myocardium.
基金supported by Natural Science Foundation of China grants10732070,10602031
文摘BK channels are widely expressed in both excitable and non-excitable cells and known to be involved in many physiological processes,such as vascular smooth tone regulation,neuronal firing and endocrine cell secretion[1].Recently, the BK channels have
文摘Aim Large conductance Ca2^＋ -activated potassium channel （BK） , expressed in the distal nephron, me- diates potassium secretion. Loss-of-function of renal BK channel is closely related with aldosteronism resulting from renal potassium retention and hyperkalemia. Natural products affecting BK functions are still scarce, especially ac- tivators. Here, the pharmacological characterization of curcumin, one of the compounds isolated from the herb Cur- cuma longa. , on B K channels have been investigated. Methods B K currents were recorded by whole-cell patch- clamp, mRNA expressions of BK were measured by quantitative real-time PCR. The surface and total protein ex- pressions of B K were assessed by surface biotinylation and Western blot. Functional study was performed on aortic rings. Results Curcumin potently increased B K currents in transfected HEK293 cells as well as the current densi- ty in A7r5 cells （ endogenous expressed BK （ α ＋ β1） channels） with ECs0 - （6.76 ± 2.24） μmol · L^-1 and （7.19 ± 0.07） μmol · L^-1, respectively. Curcumin up-regulated B K protein abundance without affecting its mR- NA expression in A7r5 cells. Surface expression and half-life of B K channels were increased by curcumin in HEK293 cells, which were abolished by MG-132, a proteasome inhibitor. Simultaneously, ERK 1/2 phosphoryla- tion was also increased by curcumin. U0126, an inhibitor of ERK, attenuate the curcumin-induced up-regulation of BK protein level. Curcumin-induced relaxation in isolated rat aortic rings was significantly attenuated by paxilline, a BK channel specific blocker. Conclusion Curcumin increased BK currents and protein abundance by inhibiting proteasomal degradation and activating ERK signaling pathway. These findings suggest that curcumin is a potential BK channel activator and provide novel insight into its complicated pharmacological effects and mechanisms.
