AIM： To explore the possibility of using the Noninvasive Micro-test Technique （NMT） to investigate the role of Transient Receptor Potential Canonical 1 （TRPC1） in regulating Ca^2＋ influxes in HL-7702 cells, a no...AIM： To explore the possibility of using the Noninvasive Micro-test Technique （NMT） to investigate the role of Transient Receptor Potential Canonical 1 （TRPC1） in regulating Ca^2＋ influxes in HL-7702 cells, a normal human liver cell line.METHODS： Net Ca^2＋ fluxes were measured with NMT, a technology that can obtain dynamic information of specific/selective ionic/molecular activities on material surfaces, non-invasively. The expression levels of TRPCl were increased by liposomal transfection, whose effectiveness was evaluated by Western-blotting and single cell reverse transcription-polymerase chain reaction.RESULTS： Ca^2＋ influxes could be elicited by adding 1 mmol/L CaCl2 to the test solution of HL-7702 cells. They were enhanced by addition of 20 μmol/L noradrenalin and inhibited by 100 μmol/L LaCl3 （a non-selective Ca^2＋ channel blocker）; 5 μmol/L nifedipine did not induce any change. Overexpression of TRPCl caused increased Ca^2＋ influx. Five micromoles per liter nifedipine did not inhibit this elevation, whereas 100 μmol/L LaCI3 did.CONCLUSION： In HL-7702 cells, there is a type of TRPCl-dependent Ca^2＋ channel, which could be detected v/a NMT and inhibited by La^3＋.展开更多
Ion channels modulate cellular excitability by regulating ionic fluxes across biological membranes.Pathogenic mutations in ion channel genes give rise to epileptic disorders that are among the most frequent neurologic...Ion channels modulate cellular excitability by regulating ionic fluxes across biological membranes.Pathogenic mutations in ion channel genes give rise to epileptic disorders that are among the most frequent neurological diseases affecting millions of individuals worldwide.Epilepsies are trigge red by an imbalance between excitatory and inhibitory conductances.However,pathogenic mutations in the same allele can give rise to loss-of-function and/or gain-of-function va riants,all able to trigger epilepsy.Furthermore,certain alleles are associated with brain malformations even in the absence of a clear electrical phenotype.This body of evidence argues that the underlying epileptogenic mechanisms of ion channels are more diverse than originally thought.Studies focusing on ion channels in prenatal cortical development have shed light on this apparent paradox.The picture that emerges is that ion channels play crucial roles in landmark neurodevelopmental processes,including neuronal migration,neurite outgrowth,and synapse formation.Thus,pathogenic channel mutants can not only cause epileptic disorders by alte ring excitability,but further,by inducing morphological and synaptic abnormalities that are initiated during neocortex formation and may persist into the adult brain.展开更多
On September 10, 2015, unprecedented flood was occurred in Kinugawa River basin located on eastern Japan. It inundated 40 km2 of flood plain in Joso city, Ibaraki Prefecture, and more than 4000 people there called for...On September 10, 2015, unprecedented flood was occurred in Kinugawa River basin located on eastern Japan. It inundated 40 km2 of flood plain in Joso city, Ibaraki Prefecture, and more than 4000 people there called for help despite supposedly having sufficient time to evacuate. Some said that small initial flood before main severe flood arrived made them make a mistake in deciding whether to evacuate or stay there, despite having to actually evacuate in reality. This study focused on flood behaviour in this area, in particular, the effect of a small drainage channel lying on the flood plain which caused fast flood diffusion in case of occurring huge overflowing. Field investigations starting on time of the disaster with high-resolution positioning system were conducted to obtain spatial maps of flood depth and height. For appropriate modelling of the effect of small channel, we applied simulation model coupling 1-dimensional (1D) and 2-dimensional (2D) hydraulic scheme on the field and compared results from the 1D/2D coupled model and model without 1D scheme. The models provided information that the flood could reach 4 hours earlier to the city central of Joso city comparing in case of model without 1D scheme. The water depth rose irregularly and it was more confusing and difficult for the victims to make appropriate evacuation act.展开更多
Expression of transient receptor potential （TRP） channels is widespread with transcripts distributed throughout the brain. All TRP channel subunits are activated following phospholipase C activation and form cation-...Expression of transient receptor potential （TRP） channels is widespread with transcripts distributed throughout the brain. All TRP channel subunits are activated following phospholipase C activation and form cation-selective ion channels. Previous studies examining the existence of TRP channels in hippocampal CA1 pyramidal neurons were based on cultured neurons. Therefore, their relevance for living tissue remains unclear. In the present study, patch-clamp recordings were conducted from CA1 pyramidal neurons in hippocampal slices from 7-day-old rats. Whole-cell currents were obtained from CA1 hippocampal neurons with potentiation effects of 2-aminoethoxydiphenyl borate and lanthanum, revealing that recorded experimental currents were characteristic TRP-like channel currents. Identification of rat hippocampal mRNA transcripts of TRPC4, TRPC5, TRPV1, TRPV2, and TRPV3 channels further verified the expression of characteristic TRP-like channels on rat CA1 hippocampal neurons.展开更多
Previous voltage clamp studies have demonstrated the modulation of sperm Ca 2+ activated K + (KCa) channels expressed in Xenopus oocytes by angiotensin II (Ang II) and extracellular ATP via AT 1 receptor and ...Previous voltage clamp studies have demonstrated the modulation of sperm Ca 2+ activated K + (KCa) channels expressed in Xenopus oocytes by angiotensin II (Ang II) and extracellular ATP via AT 1 receptor and P 2U receptor, respectively. In the present study, we investigated the involvement of KCa channels in receptor regulated sperm motility of the rat using a computer aided sperm analysis system, HTM IVOS, in conjunction with Ca 2+ mobilizing agents, receptor agonists/antagonists and KCa channels blockers. The percentage of motile sperm was increased by ionomycin (0.5 μmol/L), which could be inhibited by K + channel blockers, tetraethylammonium (TEA 1 μmol/L ) or charybdotoxin (ChTX, 300 nmol/L) indicating the presence of KCa channels. Ang II, at low concentration, 10 nmol/L, was found to increase motility, however, at higher concentration, 1 μmol/L, percentage of motility was found to be suppressed. Both stimulatory and inhibitory effects of Ang II could be reversed by losartan, a specific antagonist of AT 1 receptors, but not AT 2 antagonist PD123177, indicating the involvement of AT 1 but not AT2 receptor in mediating both effects. ChTX also abolished both stimulatory and inhibitory effects of Ang II, suggesting the involvement of KCa channels. The percentage of motility was also enhanced by extracellular ATP, a factor known to be involved in sperm activation. The ATP enhanced sperm motility was mimicked by UTP, and inhibited by ChTX and reactive blue, an antagonist of P 2 receptor, indicating the involvement of both P 2U and KCa channels. RT PCR study was also conducted to confirm the expression of KCa channels, AT 1 receptors and P 2U receptor, but not AT 2 receptor, in rat caudal epididymal sperm. The present findings suggest an important role of KCa channels in the regulation of sperm motility by AT 1 and P 2U receptors.展开更多
BACKGROUND： The onset of focal cerebral ischemia activates extracellular signal-regulated kinases 1 and 2, regulates cell cycle, promotes cell proliferation and differentiation, and affects the normal stage and funct...BACKGROUND： The onset of focal cerebral ischemia activates extracellular signal-regulated kinases 1 and 2, regulates cell cycle, promotes cell proliferation and differentiation, and affects the normal stage and function of brain cells. OBJECTIVE： To observe the effects of electroacupuncture at the Ren channel on extracellular signal-regulated kinases 1/2 expression in the lateral cerebral ventricle wall of rats with focal cerebral ischemia. The effects were analyzed at different time points after intervention. DESIGN： Randomized controlled study. SETTING： Department of Anatomy, Sun Yat-Sen University. MATERIALS： A total of 60 healthy adult male Wistar rats weighing （250±10） g were provided by the Experimental Animal Center, Medical College of Sun Yat-Sen University. The animal experiment was conducted with confirmed consent by the local ethics committee. The GB6805-Ⅱ electric acupuncture apparatus was provided by Shanghai Medical Equipment High-techno Company. METHODS： The experiment was performed at the Laboratory of Anatomy, Sun Yat-Sen University, from February to July 2007. All experimental animals were randomly divided into the following groups： normal group （n = 6）, sham operation group （n = 18）, model group （n = 18）, and electroacupuncture group （n = 18）. Middle cerebral artery occlusion （MCAO） was performed in the model group and electroacupuncture group. Zea Longa＇s grading standard was used to assess neurological impairment after reperfusion; animals whose grades were between l and 4 were included in this study. The normal control group was not exposed to MCAO. In sham operation animals, the right common carotid artery （CCA） was isolated, and the external carotid artery （ECA） was damaged, but no embolism was induced. The electroacupuncture group was given acupuncture on the second day after surgery. The acupoint locations were chosen according to Experimental Acupuncture （People＇s Publishing House; 1997; First Edition）. The Chengjiang, Qihai, and Guanyuan acupoints were labeled and connected to a G6805 electroacupuncture apparatus with sparse-dense waves （sparse waves were 30 Hz, dense waves were 100 Hz）, with a frequency of 6-15 V. The duration was 20 minutes. Two days after surgery, the model and sham operation groups were placed with their backs on the operating table, but they received no acupuncture. However, the normal group received acupuncture. The experimental animals under anesthesia were sacrificed on days 7, 14, and 28 post-surgery. Western blot analysis was used to measure expression of extracellular signal-regulated kinases 1/2 in the inferior region of the lateral cerebral ventricle wall. Expression was measured in the normal group at time points corresponding to the sham operation group. MAIN OUTCOME MEASURES： Expression of extracellular signal-regulated kinases 1/2 in the inferior region of the lateral cerebral ventricle wall at different time points after intervention. RESULTS： All 60 rats were included in the final analysis, without any loss. Seven days after MCAO, there was no significant difference in extracellular signal-regulated kinases 1/2 expression in the electroacupuncture group compared to the model group （P 〉 0.05）. However, extracellular signal-regulated kinases 1/2 expression significantly increased in the model group at 14 and 28 days after treatment （P 〈 0.05）. CONCLUSION： Electroacupuncture at the Ren channel can enhance extracellular signal-regulated kinasesl/2 expression in the inferior region of the lateral cerebral ventricle wall of rats with focal cerebral ischemia. However, this effect is not apparent until 14 days after electroacupuncture intervention.展开更多
Type 2 diabetes mellitus(T2DM)is a lifelong condition and a threat to human health.Thorough understanding of its pathogenesis is acutely needed in order to devise innovative,preventative,and potentially curative pharm...Type 2 diabetes mellitus(T2DM)is a lifelong condition and a threat to human health.Thorough understanding of its pathogenesis is acutely needed in order to devise innovative,preventative,and potentially curative pharmacological interventions.MicroRNAs(miRNA),are small,non-coding,one-stranded RNA molecules,that can target and silence around 60%of all human genes through translational repression.MiR-155 is an ancient,evolutionarily well-conserved miRNA,with distinct expression profiles and multifunctionality,and a target repertoire of over 241 genes involved in numerous physiological and pathological processes including hematopoietic lineage differentiation,immunity,inflammation,viral infections,cancer,cardiovascular conditions,and particularly diabetes mellitus.MiR-155 Levels are progressively reduced in aging,obesity,sarcopenia,and T2DM.Thus,the loss of coordinated repression of multiple miR-155 targets acting as negative regulators,such as C/EBPβ,HDAC4,and SOCS1 impacts insulin signaling,deteriorating glucose homeostasis,and causing insulin resistance(IR).Moreover,deranged regulation of the renin angiotensin aldosterone system(RAAS)through loss of Angiotensin II Type 1 receptor downregulation,and negated repression of ETS-1,results in unopposed detrimental Angiotensin II effects,further promoting IR.Finally,loss of BACH1 and SOCS1 repression abolishes cytoprotective,anti-oxidant,anti-apoptotic,and anti-inflam matory cellular pathways,and promotesβ-cell loss.In contrast to RAAS inhibitor treatments that further decrease already reduced miR-155 Levels,strategies to increase an ailing miR-155 production in T2DM,e.g.,the use of metformin,mineralocorticoid receptor blockers(spironolactone,eplerenone,finerenone),and verapamil,alone or in various combinations,represent current treatment options.In the future,direct tissue delivery of miRNA analogs is likely.展开更多
基金Supported by The National Natural Science Foundation of China,No.30270532 and No.30670774Tsinghua-Yue-Yuen Medical Science Foundation,No.20240000531 and No.20240000547
文摘AIM： To explore the possibility of using the Noninvasive Micro-test Technique （NMT） to investigate the role of Transient Receptor Potential Canonical 1 （TRPC1） in regulating Ca^2＋ influxes in HL-7702 cells, a normal human liver cell line.METHODS： Net Ca^2＋ fluxes were measured with NMT, a technology that can obtain dynamic information of specific/selective ionic/molecular activities on material surfaces, non-invasively. The expression levels of TRPCl were increased by liposomal transfection, whose effectiveness was evaluated by Western-blotting and single cell reverse transcription-polymerase chain reaction.RESULTS： Ca^2＋ influxes could be elicited by adding 1 mmol/L CaCl2 to the test solution of HL-7702 cells. They were enhanced by addition of 20 μmol/L noradrenalin and inhibited by 100 μmol/L LaCl3 （a non-selective Ca^2＋ channel blocker）; 5 μmol/L nifedipine did not induce any change. Overexpression of TRPCl caused increased Ca^2＋ influx. Five micromoles per liter nifedipine did not inhibit this elevation, whereas 100 μmol/L LaCI3 did.CONCLUSION： In HL-7702 cells, there is a type of TRPCl-dependent Ca^2＋ channel, which could be detected v/a NMT and inhibited by La^3＋.
基金NJ Governor’s Council for Medical Research and Treatment of Autism predoctoral fellowship (CAUT23AFP015) to ABNational Science Foundation grant (2030348) to FS。
文摘Ion channels modulate cellular excitability by regulating ionic fluxes across biological membranes.Pathogenic mutations in ion channel genes give rise to epileptic disorders that are among the most frequent neurological diseases affecting millions of individuals worldwide.Epilepsies are trigge red by an imbalance between excitatory and inhibitory conductances.However,pathogenic mutations in the same allele can give rise to loss-of-function and/or gain-of-function va riants,all able to trigger epilepsy.Furthermore,certain alleles are associated with brain malformations even in the absence of a clear electrical phenotype.This body of evidence argues that the underlying epileptogenic mechanisms of ion channels are more diverse than originally thought.Studies focusing on ion channels in prenatal cortical development have shed light on this apparent paradox.The picture that emerges is that ion channels play crucial roles in landmark neurodevelopmental processes,including neuronal migration,neurite outgrowth,and synapse formation.Thus,pathogenic channel mutants can not only cause epileptic disorders by alte ring excitability,but further,by inducing morphological and synaptic abnormalities that are initiated during neocortex formation and may persist into the adult brain.
文摘On September 10, 2015, unprecedented flood was occurred in Kinugawa River basin located on eastern Japan. It inundated 40 km2 of flood plain in Joso city, Ibaraki Prefecture, and more than 4000 people there called for help despite supposedly having sufficient time to evacuate. Some said that small initial flood before main severe flood arrived made them make a mistake in deciding whether to evacuate or stay there, despite having to actually evacuate in reality. This study focused on flood behaviour in this area, in particular, the effect of a small drainage channel lying on the flood plain which caused fast flood diffusion in case of occurring huge overflowing. Field investigations starting on time of the disaster with high-resolution positioning system were conducted to obtain spatial maps of flood depth and height. For appropriate modelling of the effect of small channel, we applied simulation model coupling 1-dimensional (1D) and 2-dimensional (2D) hydraulic scheme on the field and compared results from the 1D/2D coupled model and model without 1D scheme. The models provided information that the flood could reach 4 hours earlier to the city central of Joso city comparing in case of model without 1D scheme. The water depth rose irregularly and it was more confusing and difficult for the victims to make appropriate evacuation act.
基金the Medical Scientific Research Foundation of Guangdong Province,No.A2006372the National Natural Science Foundation of China,No.U0632007+3 种基金the Natural Science Foundation of Guangdong Province,No.9351051501000003the Major Program of Natural Science Research of Higher Learning School of Guangdong Province,No.06Z007the Key Project of Science and Technology of Guangzhou City,No.2007zl-E0081the Program for Changjiang Scholars and Innovative Research Team,No.IRT0731
文摘Expression of transient receptor potential （TRP） channels is widespread with transcripts distributed throughout the brain. All TRP channel subunits are activated following phospholipase C activation and form cation-selective ion channels. Previous studies examining the existence of TRP channels in hippocampal CA1 pyramidal neurons were based on cultured neurons. Therefore, their relevance for living tissue remains unclear. In the present study, patch-clamp recordings were conducted from CA1 pyramidal neurons in hippocampal slices from 7-day-old rats. Whole-cell currents were obtained from CA1 hippocampal neurons with potentiation effects of 2-aminoethoxydiphenyl borate and lanthanum, revealing that recorded experimental currents were characteristic TRP-like channel currents. Identification of rat hippocampal mRNA transcripts of TRPC4, TRPC5, TRPV1, TRPV2, and TRPV3 channels further verified the expression of characteristic TRP-like channels on rat CA1 hippocampal neurons.
基金Direct Grant of the Chinese University of Hong Kong to Dr. HC Chan
文摘Previous voltage clamp studies have demonstrated the modulation of sperm Ca 2+ activated K + (KCa) channels expressed in Xenopus oocytes by angiotensin II (Ang II) and extracellular ATP via AT 1 receptor and P 2U receptor, respectively. In the present study, we investigated the involvement of KCa channels in receptor regulated sperm motility of the rat using a computer aided sperm analysis system, HTM IVOS, in conjunction with Ca 2+ mobilizing agents, receptor agonists/antagonists and KCa channels blockers. The percentage of motile sperm was increased by ionomycin (0.5 μmol/L), which could be inhibited by K + channel blockers, tetraethylammonium (TEA 1 μmol/L ) or charybdotoxin (ChTX, 300 nmol/L) indicating the presence of KCa channels. Ang II, at low concentration, 10 nmol/L, was found to increase motility, however, at higher concentration, 1 μmol/L, percentage of motility was found to be suppressed. Both stimulatory and inhibitory effects of Ang II could be reversed by losartan, a specific antagonist of AT 1 receptors, but not AT 2 antagonist PD123177, indicating the involvement of AT 1 but not AT2 receptor in mediating both effects. ChTX also abolished both stimulatory and inhibitory effects of Ang II, suggesting the involvement of KCa channels. The percentage of motility was also enhanced by extracellular ATP, a factor known to be involved in sperm activation. The ATP enhanced sperm motility was mimicked by UTP, and inhibited by ChTX and reactive blue, an antagonist of P 2 receptor, indicating the involvement of both P 2U and KCa channels. RT PCR study was also conducted to confirm the expression of KCa channels, AT 1 receptors and P 2U receptor, but not AT 2 receptor, in rat caudal epididymal sperm. The present findings suggest an important role of KCa channels in the regulation of sperm motility by AT 1 and P 2U receptors.
基金the National Natural Science Foundation of China, No. 30371808Post-doctor's Project of Guangzhou University of Traditional Chinese Medicine, No.106B3YH0411
文摘BACKGROUND： The onset of focal cerebral ischemia activates extracellular signal-regulated kinases 1 and 2, regulates cell cycle, promotes cell proliferation and differentiation, and affects the normal stage and function of brain cells. OBJECTIVE： To observe the effects of electroacupuncture at the Ren channel on extracellular signal-regulated kinases 1/2 expression in the lateral cerebral ventricle wall of rats with focal cerebral ischemia. The effects were analyzed at different time points after intervention. DESIGN： Randomized controlled study. SETTING： Department of Anatomy, Sun Yat-Sen University. MATERIALS： A total of 60 healthy adult male Wistar rats weighing （250±10） g were provided by the Experimental Animal Center, Medical College of Sun Yat-Sen University. The animal experiment was conducted with confirmed consent by the local ethics committee. The GB6805-Ⅱ electric acupuncture apparatus was provided by Shanghai Medical Equipment High-techno Company. METHODS： The experiment was performed at the Laboratory of Anatomy, Sun Yat-Sen University, from February to July 2007. All experimental animals were randomly divided into the following groups： normal group （n = 6）, sham operation group （n = 18）, model group （n = 18）, and electroacupuncture group （n = 18）. Middle cerebral artery occlusion （MCAO） was performed in the model group and electroacupuncture group. Zea Longa＇s grading standard was used to assess neurological impairment after reperfusion; animals whose grades were between l and 4 were included in this study. The normal control group was not exposed to MCAO. In sham operation animals, the right common carotid artery （CCA） was isolated, and the external carotid artery （ECA） was damaged, but no embolism was induced. The electroacupuncture group was given acupuncture on the second day after surgery. The acupoint locations were chosen according to Experimental Acupuncture （People＇s Publishing House; 1997; First Edition）. The Chengjiang, Qihai, and Guanyuan acupoints were labeled and connected to a G6805 electroacupuncture apparatus with sparse-dense waves （sparse waves were 30 Hz, dense waves were 100 Hz）, with a frequency of 6-15 V. The duration was 20 minutes. Two days after surgery, the model and sham operation groups were placed with their backs on the operating table, but they received no acupuncture. However, the normal group received acupuncture. The experimental animals under anesthesia were sacrificed on days 7, 14, and 28 post-surgery. Western blot analysis was used to measure expression of extracellular signal-regulated kinases 1/2 in the inferior region of the lateral cerebral ventricle wall. Expression was measured in the normal group at time points corresponding to the sham operation group. MAIN OUTCOME MEASURES： Expression of extracellular signal-regulated kinases 1/2 in the inferior region of the lateral cerebral ventricle wall at different time points after intervention. RESULTS： All 60 rats were included in the final analysis, without any loss. Seven days after MCAO, there was no significant difference in extracellular signal-regulated kinases 1/2 expression in the electroacupuncture group compared to the model group （P 〉 0.05）. However, extracellular signal-regulated kinases 1/2 expression significantly increased in the model group at 14 and 28 days after treatment （P 〈 0.05）. CONCLUSION： Electroacupuncture at the Ren channel can enhance extracellular signal-regulated kinasesl/2 expression in the inferior region of the lateral cerebral ventricle wall of rats with focal cerebral ischemia. However, this effect is not apparent until 14 days after electroacupuncture intervention.
文摘Type 2 diabetes mellitus(T2DM)is a lifelong condition and a threat to human health.Thorough understanding of its pathogenesis is acutely needed in order to devise innovative,preventative,and potentially curative pharmacological interventions.MicroRNAs(miRNA),are small,non-coding,one-stranded RNA molecules,that can target and silence around 60%of all human genes through translational repression.MiR-155 is an ancient,evolutionarily well-conserved miRNA,with distinct expression profiles and multifunctionality,and a target repertoire of over 241 genes involved in numerous physiological and pathological processes including hematopoietic lineage differentiation,immunity,inflammation,viral infections,cancer,cardiovascular conditions,and particularly diabetes mellitus.MiR-155 Levels are progressively reduced in aging,obesity,sarcopenia,and T2DM.Thus,the loss of coordinated repression of multiple miR-155 targets acting as negative regulators,such as C/EBPβ,HDAC4,and SOCS1 impacts insulin signaling,deteriorating glucose homeostasis,and causing insulin resistance(IR).Moreover,deranged regulation of the renin angiotensin aldosterone system(RAAS)through loss of Angiotensin II Type 1 receptor downregulation,and negated repression of ETS-1,results in unopposed detrimental Angiotensin II effects,further promoting IR.Finally,loss of BACH1 and SOCS1 repression abolishes cytoprotective,anti-oxidant,anti-apoptotic,and anti-inflam matory cellular pathways,and promotesβ-cell loss.In contrast to RAAS inhibitor treatments that further decrease already reduced miR-155 Levels,strategies to increase an ailing miR-155 production in T2DM,e.g.,the use of metformin,mineralocorticoid receptor blockers(spironolactone,eplerenone,finerenone),and verapamil,alone or in various combinations,represent current treatment options.In the future,direct tissue delivery of miRNA analogs is likely.
