Atrial fibrillation(AF)is the most common cardiac arrhythmia worldwide.The prevalence of the disease increases with age,strongly implying an age-related process underlying the pathology.At a time when people are livin...Atrial fibrillation(AF)is the most common cardiac arrhythmia worldwide.The prevalence of the disease increases with age,strongly implying an age-related process underlying the pathology.At a time when people are living longer than ever before,an exponential increase in disease prevalence is predicted worldwide.Hence unraveling the underlying mechanics of the disease is paramount for the development of innovative treatment and prevention strategies.The role of voltage-gated sodium channels is fundamental in cardiac electrophysiology and may provide novel insights into the arrhythmogenesis of AF.Na_v1.5 is the predominant cardiac isoform,responsible for the action potential upstroke.Recent studies have demonstrated that Na_v1.8(an isoform predominantly expressed within the peripheral nervous system)is responsible for cellular arrhythmogenesis through the enhancement of pro-arrhythmogenic currents.Animal studies have shown a decline in Na_v1.5 leading to a diminished action potential upstroke during phase 0.Furthermore,the study of human tissue demonstrates an inverse expression of sodium channel isoforms;reduction of Na_v1.5 and increase of Na_v1.8 in both heart failure and ventricular hypertrophy.This strongly suggests that the expression of voltage-gated sodium channels play a crucial role in the development of arrhythmias in the diseased heart.Targeting aberrant sodium currents has led to novel therapeutic approaches in tackling AF and continues to be an area of emerging research.This review will explore how voltage-gated sodium channels may predispose the elderly heart to AF through the examination of laboratory and clinical based evidence.展开更多
Neuropathic pain has been hypothesized to be the result of aberrant expression and function of sodium channels at the site of injury. To investigate the effects of NaV1.8 antisense oligonucleotide on the expression of...Neuropathic pain has been hypothesized to be the result of aberrant expression and function of sodium channels at the site of injury. To investigate the effects of NaV1.8 antisense oligonucleotide on the expression of sodium channel mRNA in dorsal root ganglion （DRG） neurons in chronic neuropathic pain. 24 Sprague-Dawley rats weighing 200--260 g were anesthetized with the intraperitoneal injection of 300 mg· kg^-1 choral hydrate. The CCI model was made by loose ligation of sciatic nerve trunk by 4--0 chromic gut. The mechanical and thermal pain threshold were measured before operation and 1, 3, 5, 7, 9, 11, 13 days after operation. A PE-10 catheter was implanted in subarachnoid space at lumbar region. On the 7th postoperative day the animals were randomly divided into 4 groups. The drugs were injected intrathecally twice a day for 5 consecutive days in group 2--4. The animals were decapitated 14 days after the surgery. The L4--L6 DRG of the operated side was removed and crushed, and total RNA was extracted with Trizol reagent. The contralateral side was used as control. The change of NaV1.8 sodium channel transcripts was determined by RT-PCR. Pain threshold was significantly lowered after CCI as compared with that in control group and was elevated 3 days after antisense oligonucleotide injection. Sensory neuron specific TTX-R sodium channel NaV1.8 transcript was down-regulated after antisense oligonucleotide injection at the dosage of 45 μg as compared with that in CCI group （P〈0.01）, and it was even greater at the dosage of 90 μg. The intrathecally injected NaV1.8 antisense oligonucleotide can reduce the mechanical allodynia and thermal hyperalgesia partially by downregulating the SNS transcript expression.展开更多
Voltage-gated sodium(Nav)channels are critical players in the generation and propagation of action potentials by triggering membrane depolarization.Mutations in Nav channels are associated with a variety of channelopa...Voltage-gated sodium(Nav)channels are critical players in the generation and propagation of action potentials by triggering membrane depolarization.Mutations in Nav channels are associated with a variety of channelopathies,which makes them relevant targets for pharmaceutical intervention.Sofar,the cryoelectron microscopic structure of the human Nav 1.2,Nav 1.4,and Nav 1.7 has been reported,which sheds light on the molecular basis of functional mechanism of Nav channels and provides a path toward structure-based drug discovery.In this review,we focus on the recent advances in the structure,molecular mechanism and modulation of Nav channels,and state updated sodium channel blockers for the treatment of pathophysiology disorders and briefly discuss where the blockers may be developed in the future.展开更多
Growth differentiation factor 15(GDF-15)is a member of the transforming growth factor-βsuperfamily.It is widely distributed in the central and peripheral nervous systems.Whether and how GDF-15 modulates nociceptive s...Growth differentiation factor 15(GDF-15)is a member of the transforming growth factor-βsuperfamily.It is widely distributed in the central and peripheral nervous systems.Whether and how GDF-15 modulates nociceptive signaling remains unclear.Behaviorally,we found that peripheral GDF-15 significantly elevated nociceptive response thresholds to mechanical and thermal stimuli in naïve and arthritic rats.Electrophysiologically,we demonstrated that GDF-15 decreased the excitability of small-diameter dorsal root ganglia(DRG)neurons.Furthermore,GDF-15 concentration-dependently suppressed tetrodotoxin-resistant sodium channel Nav1.8 currents,and shifted the steady-state inactivation curves of Nav1.8 in a hyperpolarizing direction.GDF-15 also reduced window currents and slowed down the recovery rate of Nav1.8 channels,suggesting that GDF-15 accelerated inactivation and slowed recovery of the channel.Immunohistochemistry results showed that activin receptor-like kinase-2(ALK2)was widely expressed in DRG medium-and small-diameter neurons,and some of them were Nav1.8-positive.Blockade of ALK2 prevented the GDF-15-induced inhibition of Nav1.8 currents and nociceptive behaviors.Inhibition of PKA and ERK,but not PKC,blocked the inhibitory effect of GDF-15 on Nav1.8 currents.These results suggest a functional link between GDF-15 and Nav1.8 in DRG neurons via ALK2 receptors and PKA associated with MEK/ERK,which mediate the peripheral analgesia of GDF-15.展开更多
Voltage-gated sodium channels play an important role in the generation and propagation of action potentials in excitable cells. They are composed of a pore-forming α subunit and auxiliary β subunits. To date, nine s...Voltage-gated sodium channels play an important role in the generation and propagation of action potentials in excitable cells. They are composed of a pore-forming α subunit and auxiliary β subunits. To date, nine subtypes of the α subunit, designated Nav1.1 to Nav1.9, have been shown to form functional sodium channels. In addition, four different mammalian subunits （β1-β4） isoforms have been cloned from the nervous system. The β subunits are structurally homologous and form single transmembrane glycoproteins with short intracellular loops and immunoglobulin-like extracellular segments. The association of the various α subtypes with different combinations of auxiliary β subunits creates the possibility of additional molecular and functional complexity for neuronal sodium channels.展开更多
Objective:The objective of this study is to investigate the inhibitory effect of peony and licorice decoction and its compatibility components on the Nav1.4 voltage-gated sodium channels(VGSCs).Materials and Methods:W...Objective:The objective of this study is to investigate the inhibitory effect of peony and licorice decoction and its compatibility components on the Nav1.4 voltage-gated sodium channels(VGSCs).Materials and Methods:Writhing test was carried out with ICR mice.Paeonia lactiflora and Glycyrrhiza uralensis group were administrated 0.2 ml of solution of freeze-dried powder dissolved in normal saline with the concentration of 2.94 mg/ml,1.47 mg/ml,and 0.74 mg/ml using intragastric administration,respectively.Peony and licorice decoction groups were administrated 0.2 ml of solution of freeze-dried powder dissolved in normal saline with the concentration of 5.89 mg/ml,2.94 mg/ml,and 1.47 mg/ml using intragastric administration,respectively.For electrophysiology studies,each freeze-dried powder was dissolved in DMSO to make 10 mg/ml and 50 mg/ml stock solutions.The electrophysiological recordings were obtained under visual control of a microscope.For UPLC analysis,the freeze-dried powder was dissolved in methanol and then determines the contents of the nine marker compounds.Results:The effect of G.uralensis on incubation period and writhing frequency was significantly better than that of peony and licorice decoction group and P.lactiflora group.The inhibition rate of 50 mg/ml water extracts of the three samples was significantly higher than that of the 10 mg/ml group.Moreover,the water extract of G.uralensis at 50 mg/ml had the strongest inhibitory effect on I_(Nav) 1.4 of the three.Conclusion:The possible mechanism of peony and licorice decoction in relieving spasm and pain is most likely by inhibiting Voltage-Gated Sodium Channel Subtype 1.4.展开更多
Three novel series of α-aminoamides derivatives were designed and synthesized based on ralfinamide,and their Nav1.7 inhibitory activities were evaluated using manual patch clamp electrophysiology. Active compounds in...Three novel series of α-aminoamides derivatives were designed and synthesized based on ralfinamide,and their Nav1.7 inhibitory activities were evaluated using manual patch clamp electrophysiology. Active compounds inhibited Nav1.7 with half maximal inhibitory concentration(IC_(50)) values ranging from2.9 μmol/L to 21.4 μmol/L. Among them, the most potent compound 19h exhibited about 12-fold potency better than ralfinamide. The investigation of their structure-activity relationship gives a strategy to improve the Nav1.7 inhibition of ralfinamide analogues. Compound 19h was efficacious in antinociception in the mouse spared nerve injury(SNI) model of neuropathic pain without causing sedation in the open field test.展开更多
Objectives This experiment used whole-cell patch-clamp technique to investigate the course of recovery from use- dependent block of Na ＋ channels （Nav 1.5） in human embryonic kidney （HEK） cells, on which to veri...Objectives This experiment used whole-cell patch-clamp technique to investigate the course of recovery from use- dependent block of Na ＋ channels （Nav 1.5） in human embryonic kidney （HEK） cells, on which to verify the effects of volatile oil of Nardostachy chinesis Batal （Gansong）. Methods Two pulses generated by computer followed by a recovery pulse and a test pulse, the interval duration between the two pulses varied from 16 ms to 1 s, and holding potential is -80 mV to - 140 inV. The peak Na^＋ current for a given recovery time was normalized to the tully recovered peak current, and the normalized value was the plot as a function of the recovery time to study the effects of 3 ppm concentration Gansong volatile oil on recovery from use-dependent block of Navl. 5 in HEK. Results It showed that Gansong group, comparing with control group, delayed the time courses of recovery from use-dependent block [ （33.2± 5.77 ） ms for control group and （52.5± 6.08 ） ms for 3 ppm Gansong group, P 〈 0.05 ] In the presence of Gansong, inhibition of the Na^＋ current was enhanced by increasing frequency of depolarizing pulse from 56.5 ms to 16 ms. In the control group, the time course of recovery showed that recovery started at 19.5 ms and finished by 36.5 ms. In the presence of Gansong, the time course of recovery showed that recovery started at 36.5 ms and finished by 56.5 ms. Na^＋ currents recovered from the use-dependent block varying with holding potential （holding potential-dependent）. Conclusions The results suggested that Na ＋ currents recovered from the use-dependent block correlated with persistent time, holding potential. The Gansong volatile oil has inhibitive effect on the Na^＋ current recovery.展开更多
文摘Atrial fibrillation(AF)is the most common cardiac arrhythmia worldwide.The prevalence of the disease increases with age,strongly implying an age-related process underlying the pathology.At a time when people are living longer than ever before,an exponential increase in disease prevalence is predicted worldwide.Hence unraveling the underlying mechanics of the disease is paramount for the development of innovative treatment and prevention strategies.The role of voltage-gated sodium channels is fundamental in cardiac electrophysiology and may provide novel insights into the arrhythmogenesis of AF.Na_v1.5 is the predominant cardiac isoform,responsible for the action potential upstroke.Recent studies have demonstrated that Na_v1.8(an isoform predominantly expressed within the peripheral nervous system)is responsible for cellular arrhythmogenesis through the enhancement of pro-arrhythmogenic currents.Animal studies have shown a decline in Na_v1.5 leading to a diminished action potential upstroke during phase 0.Furthermore,the study of human tissue demonstrates an inverse expression of sodium channel isoforms;reduction of Na_v1.5 and increase of Na_v1.8 in both heart failure and ventricular hypertrophy.This strongly suggests that the expression of voltage-gated sodium channels play a crucial role in the development of arrhythmias in the diseased heart.Targeting aberrant sodium currents has led to novel therapeutic approaches in tackling AF and continues to be an area of emerging research.This review will explore how voltage-gated sodium channels may predispose the elderly heart to AF through the examination of laboratory and clinical based evidence.
文摘Neuropathic pain has been hypothesized to be the result of aberrant expression and function of sodium channels at the site of injury. To investigate the effects of NaV1.8 antisense oligonucleotide on the expression of sodium channel mRNA in dorsal root ganglion （DRG） neurons in chronic neuropathic pain. 24 Sprague-Dawley rats weighing 200--260 g were anesthetized with the intraperitoneal injection of 300 mg· kg^-1 choral hydrate. The CCI model was made by loose ligation of sciatic nerve trunk by 4--0 chromic gut. The mechanical and thermal pain threshold were measured before operation and 1, 3, 5, 7, 9, 11, 13 days after operation. A PE-10 catheter was implanted in subarachnoid space at lumbar region. On the 7th postoperative day the animals were randomly divided into 4 groups. The drugs were injected intrathecally twice a day for 5 consecutive days in group 2--4. The animals were decapitated 14 days after the surgery. The L4--L6 DRG of the operated side was removed and crushed, and total RNA was extracted with Trizol reagent. The contralateral side was used as control. The change of NaV1.8 sodium channel transcripts was determined by RT-PCR. Pain threshold was significantly lowered after CCI as compared with that in control group and was elevated 3 days after antisense oligonucleotide injection. Sensory neuron specific TTX-R sodium channel NaV1.8 transcript was down-regulated after antisense oligonucleotide injection at the dosage of 45 μg as compared with that in CCI group （P〈0.01）, and it was even greater at the dosage of 90 μg. The intrathecally injected NaV1.8 antisense oligonucleotide can reduce the mechanical allodynia and thermal hyperalgesia partially by downregulating the SNS transcript expression.
基金the National Natural Science Foundation of China(Nos.81473254,81773637,81773594,U1703111)the Fundamental Research Fund for the Central Universities(No.2017KFYXJJ151).
文摘Voltage-gated sodium(Nav)channels are critical players in the generation and propagation of action potentials by triggering membrane depolarization.Mutations in Nav channels are associated with a variety of channelopathies,which makes them relevant targets for pharmaceutical intervention.Sofar,the cryoelectron microscopic structure of the human Nav 1.2,Nav 1.4,and Nav 1.7 has been reported,which sheds light on the molecular basis of functional mechanism of Nav channels and provides a path toward structure-based drug discovery.In this review,we focus on the recent advances in the structure,molecular mechanism and modulation of Nav channels,and state updated sodium channel blockers for the treatment of pathophysiology disorders and briefly discuss where the blockers may be developed in the future.
基金This work was supported by the National Natural Science Foundation of China(82021002,31771164,and 31930042)the National Key R&D Program of China(2017YFB0403803)+1 种基金the Innovative Research Team of High-level Local Universities in Shanghai,Shanghai Municipal Science and Technology Major Project(2018SHZDZX01)Zhang Jiang Laboratory.
文摘Growth differentiation factor 15(GDF-15)is a member of the transforming growth factor-βsuperfamily.It is widely distributed in the central and peripheral nervous systems.Whether and how GDF-15 modulates nociceptive signaling remains unclear.Behaviorally,we found that peripheral GDF-15 significantly elevated nociceptive response thresholds to mechanical and thermal stimuli in naïve and arthritic rats.Electrophysiologically,we demonstrated that GDF-15 decreased the excitability of small-diameter dorsal root ganglia(DRG)neurons.Furthermore,GDF-15 concentration-dependently suppressed tetrodotoxin-resistant sodium channel Nav1.8 currents,and shifted the steady-state inactivation curves of Nav1.8 in a hyperpolarizing direction.GDF-15 also reduced window currents and slowed down the recovery rate of Nav1.8 channels,suggesting that GDF-15 accelerated inactivation and slowed recovery of the channel.Immunohistochemistry results showed that activin receptor-like kinase-2(ALK2)was widely expressed in DRG medium-and small-diameter neurons,and some of them were Nav1.8-positive.Blockade of ALK2 prevented the GDF-15-induced inhibition of Nav1.8 currents and nociceptive behaviors.Inhibition of PKA and ERK,but not PKC,blocked the inhibitory effect of GDF-15 on Nav1.8 currents.These results suggest a functional link between GDF-15 and Nav1.8 in DRG neurons via ALK2 receptors and PKA associated with MEK/ERK,which mediate the peripheral analgesia of GDF-15.
基金grants from the National Natural Science Foundation of China(No.30300330)Qimingxing program of Shanghai(No.05QMX1431)
文摘Voltage-gated sodium channels play an important role in the generation and propagation of action potentials in excitable cells. They are composed of a pore-forming α subunit and auxiliary β subunits. To date, nine subtypes of the α subunit, designated Nav1.1 to Nav1.9, have been shown to form functional sodium channels. In addition, four different mammalian subunits （β1-β4） isoforms have been cloned from the nervous system. The β subunits are structurally homologous and form single transmembrane glycoproteins with short intracellular loops and immunoglobulin-like extracellular segments. The association of the various α subtypes with different combinations of auxiliary β subunits creates the possibility of additional molecular and functional complexity for neuronal sodium channels.
基金financial supports from "Study on the Development of Classical Prescriptions of Peony and Liquorice Decoction"(NO:H2016072-03)"Study on the Standard Decoction of Traditional Chinese Medicinal Slices"(NO:H2016021-06)
文摘Objective:The objective of this study is to investigate the inhibitory effect of peony and licorice decoction and its compatibility components on the Nav1.4 voltage-gated sodium channels(VGSCs).Materials and Methods:Writhing test was carried out with ICR mice.Paeonia lactiflora and Glycyrrhiza uralensis group were administrated 0.2 ml of solution of freeze-dried powder dissolved in normal saline with the concentration of 2.94 mg/ml,1.47 mg/ml,and 0.74 mg/ml using intragastric administration,respectively.Peony and licorice decoction groups were administrated 0.2 ml of solution of freeze-dried powder dissolved in normal saline with the concentration of 5.89 mg/ml,2.94 mg/ml,and 1.47 mg/ml using intragastric administration,respectively.For electrophysiology studies,each freeze-dried powder was dissolved in DMSO to make 10 mg/ml and 50 mg/ml stock solutions.The electrophysiological recordings were obtained under visual control of a microscope.For UPLC analysis,the freeze-dried powder was dissolved in methanol and then determines the contents of the nine marker compounds.Results:The effect of G.uralensis on incubation period and writhing frequency was significantly better than that of peony and licorice decoction group and P.lactiflora group.The inhibition rate of 50 mg/ml water extracts of the three samples was significantly higher than that of the 10 mg/ml group.Moreover,the water extract of G.uralensis at 50 mg/ml had the strongest inhibitory effect on I_(Nav) 1.4 of the three.Conclusion:The possible mechanism of peony and licorice decoction in relieving spasm and pain is most likely by inhibiting Voltage-Gated Sodium Channel Subtype 1.4.
基金Financial supports by National Natural Science Foundation of China (Nos. 82003565 and 81973162)the Science and Technology Commission of Shanghai Municipality (No. 20S11902300,China)。
文摘Three novel series of α-aminoamides derivatives were designed and synthesized based on ralfinamide,and their Nav1.7 inhibitory activities were evaluated using manual patch clamp electrophysiology. Active compounds inhibited Nav1.7 with half maximal inhibitory concentration(IC_(50)) values ranging from2.9 μmol/L to 21.4 μmol/L. Among them, the most potent compound 19h exhibited about 12-fold potency better than ralfinamide. The investigation of their structure-activity relationship gives a strategy to improve the Nav1.7 inhibition of ralfinamide analogues. Compound 19h was efficacious in antinociception in the mouse spared nerve injury(SNI) model of neuropathic pain without causing sedation in the open field test.
基金National Natural Science Foundation of People's Republic of China(No.30660060)
文摘Objectives This experiment used whole-cell patch-clamp technique to investigate the course of recovery from use- dependent block of Na ＋ channels （Nav 1.5） in human embryonic kidney （HEK） cells, on which to verify the effects of volatile oil of Nardostachy chinesis Batal （Gansong）. Methods Two pulses generated by computer followed by a recovery pulse and a test pulse, the interval duration between the two pulses varied from 16 ms to 1 s, and holding potential is -80 mV to - 140 inV. The peak Na^＋ current for a given recovery time was normalized to the tully recovered peak current, and the normalized value was the plot as a function of the recovery time to study the effects of 3 ppm concentration Gansong volatile oil on recovery from use-dependent block of Navl. 5 in HEK. Results It showed that Gansong group, comparing with control group, delayed the time courses of recovery from use-dependent block [ （33.2± 5.77 ） ms for control group and （52.5± 6.08 ） ms for 3 ppm Gansong group, P 〈 0.05 ] In the presence of Gansong, inhibition of the Na^＋ current was enhanced by increasing frequency of depolarizing pulse from 56.5 ms to 16 ms. In the control group, the time course of recovery showed that recovery started at 19.5 ms and finished by 36.5 ms. In the presence of Gansong, the time course of recovery showed that recovery started at 36.5 ms and finished by 56.5 ms. Na^＋ currents recovered from the use-dependent block varying with holding potential （holding potential-dependent）. Conclusions The results suggested that Na ＋ currents recovered from the use-dependent block correlated with persistent time, holding potential. The Gansong volatile oil has inhibitive effect on the Na^＋ current recovery.
