We recently demonstrated a repurposing beneficial effect of 4-aminopyridine(4-AP),a potassium channel blocker,on functional recove ry and muscle atrophy after sciatic nerve crush injury in rodents.However,this effect ...We recently demonstrated a repurposing beneficial effect of 4-aminopyridine(4-AP),a potassium channel blocker,on functional recove ry and muscle atrophy after sciatic nerve crush injury in rodents.However,this effect of 4-AP is unknown in nerve transection,gap,and grafting models.To evaluate and compare the functional recovery,nerve morphology,and muscle atrophy,we used a novel stepwise nerve transection with gluing(STG),as well as 7-mm irreparable nerve gap(G-7/0)and 7-mm isografting in 5-mm gap(G-5/7)models in the absence and presence of 4-AP treatment.Following surgery,sciatic functional index was determined wee kly to evaluate the direct in vivo global motor functional recovery.After 12 weeks,nerves were processed for whole-mount immunofluorescence imaging,and tibialis anterior muscles were harvested for wet weight and quantitative histomorphological analyses for muscle fiber crosssectional area and minimal Feret's diameter.Average post-injury sciatic functional index values in STG and G-5/7 models were significantly greater than those in the G-7/0 model.4-AP did not affect the sciatic functional index recovery in any model.Compared to STG,nerve imaging revealed more misdirected axons and distorted nerve architecture with isografting.While muscle weight,cross-sectional area,and minimal Feret's diameter were significantly smaller in G-7/0 model compared with STG and G-5/7,4-AP treatment significantly increased right TA muscle mass,cross-sectional area,and minimal Feret's diameter in G-7/0 model.These findings demonstrate that functional recovery and muscle atrophy after peripheral nerve injury are directly related to the intervening nerve gap,and 4-AP exerts diffe rential effects on functional recove ry and muscle atrophy.展开更多
Oral 4-aminopyridine(4-AP)is clinically used for symptomatic relief in multiple sclerosis and we recently demonstrated that systemic 4-AP had previously unknown clinically-relevant effects after traumatic peripheral n...Oral 4-aminopyridine(4-AP)is clinically used for symptomatic relief in multiple sclerosis and we recently demonstrated that systemic 4-AP had previously unknown clinically-relevant effects after traumatic peripheral nerve injury including the promotion of re-myelination,improvement of nerve conductivity,and acceleration of functional recovery.We hypothesized that,instead of oral or injection administration,transdermal 4-AP(TD-4-AP)could also improve functional recovery after traumatic peripheral nerve injury.Mice with surgical traumatic peripheral nerve injury received TD-4AP or vehicle alone and were examined for skin permeability,pharmacokinetics,functional,electrophysiological,and nerve morphological properties.4-AP showed linear pharmacokinetics and the maximum plasma 4-AP concentrations were proportional to TD-4-AP dose.While a single dose of TD-4-AP administration demonstrated rapid transient improvement in motor function,chronic TD-4-AP treatment significantly improved motor function and nerve conduction and these effects were associated with fewer degenerating axons and thicker myelin sheaths than those from vehicle controls.These findings provide direct evidence for the potential transdermal applicability of 4-AP and demonstrate that 4-AP delivered through the skin can enhance in-vivo functional recovery and nerve conduction while decreasing axonal degeneration.The animal experiments were approved by the University Committee on Animal Research(UCAR)at the University of Rochester(UCAR-2009-019)on March 31,2017.展开更多
4-Aminopyridine(4-AP), an FDA-approved drug for the symptomatic treatment of multiple sclerosis, is used to improve neuromuscular function in patients with diverse demyelinating disorders. We recently demonstrated tha...4-Aminopyridine(4-AP), an FDA-approved drug for the symptomatic treatment of multiple sclerosis, is used to improve neuromuscular function in patients with diverse demyelinating disorders. We recently demonstrated that local, transdermal or injectable forms of 4-AP improve myelination, nerve conduction velocity, muscle atrophy, and motor function after traumatic peripheral nerve injury in mice. While oral 4-AP is most commonly used in the clinic, it is unknown whether human equivalent oral doses of 4-AP have effects on traumatic peripheral nerve injury differentiation, myelination, muscle atrophy, functional recovery, and post-injury inflammatory processes in animals. Mice with sciatic nerve crush or denervation injury received oral or intraperitoneal 4-AP(10 μg) or vehicle alone and were examined for pharmacokinetics, motor function, muscle mass, intrinsic muscle force, nerve morphological and gene expression profiles. 4-AP showed linear pharmacokinetics and the maximum plasma 4-AP concentrations were proportional to 4-AP dose. Acute single dose of oral 4-AP administration induced a rapid transient improvement in motor function that was different in traumatic peripheral nerve injury with or without nerve continuity, chronic daily oral 4-AP treatment significantly enhanced post crush injury motor function recovery and this effect was associated with improved myelination, muscle mass, and ex vivo muscle force. Polymerase chain reaction array analysis with crushed nerve revealed significant alterations in gene involved in axonal inflammation and regeneration. These findings provide convincing evidence that regardless of the route of administration, 4-AP can acutely differentiate traumatic peripheral nerve injury with or without nerve continuity and can enhance in vivo functional recovery with better preservation of myelin sheaths, muscle mass, and muscle force. The animal experiments were approved by the University Committee on Animal Research(UCAR) at the University of Rochester(UCAR-2009-019) on March 31, 2017.展开更多
The binding interactions between 4-aminopyridine(4-AP) and a series of cucurbit[n]urils(Q[5], Q[6],TMe Q[6], Q[7], Q[8]) have been studied using1H NMR spectroscopy, UV–vis absorption spectroscopy,isothermal titration...The binding interactions between 4-aminopyridine(4-AP) and a series of cucurbit[n]urils(Q[5], Q[6],TMe Q[6], Q[7], Q[8]) have been studied using1H NMR spectroscopy, UV–vis absorption spectroscopy,isothermal titration calorimetry(ITC) and X-ray crystallography. The data indicates that the Q[5]@4-AP complex exhibits exo binding, which is not observed in the other four host-guest complexes. Furthermore,X-ray crystallography clearly reveals how the Q[n]s bind with 4-AP to form complexes, for example Q[5]forms an outer-surface complex, whilst Q[6], TMe Q[6] and Q[7] formed 1:1 host and guest type complexes, and Q[8] formed a stable 1:2 ternary complex due to its large cavity, which can accommodate two 4-AP molecules.展开更多
三叉神经痛(trigeminal neuralgia)是临床上的顽疾,长期以来为医学界所重视,但其发病机制尚不清晰,临床上也无有效的治疗方法。本研究首先通过免疫荧光化学法和动物行为学测定,对经眶下孔达三叉神经节目标注射给药法的效果进行了评价,...三叉神经痛(trigeminal neuralgia)是临床上的顽疾,长期以来为医学界所重视,但其发病机制尚不清晰,临床上也无有效的治疗方法。本研究首先通过免疫荧光化学法和动物行为学测定,对经眶下孔达三叉神经节目标注射给药法的效果进行了评价,然后行眶下神经慢性缩窄环术(chronic constriction injury of the infraorbital nerve,ION-CCI)建立三叉神经病理性痛大鼠模型,用经眶下孔达三叉神经节目标注射法分别注射BKCa通道激动剂NS1619和Kv通道拮抗剂4-AP,观察药物对大鼠面部机械痛阈的影响。结果显示,通过经眶下孔达三叉神经节目标注射法,药物可以准确到达三叉神经节,并产生了比一般眶下孔注射给药法更为持久的注射效果。ION-CCI术后第6天大鼠术侧面部触须垫部产生了显著的异常性疼痛(allodynia),并可以维持到至少术后第42天。在ION-CCI术后第15天大鼠,运用经眶下孔达三叉神经节目标注射法注射BKCa通道激动剂NS1619可以剂量依赖性地显著提高ION-CCI组大鼠的面部机械痛阈,逆转面部痛觉过敏;而在ION-CCI术后第35天痛阈部分恢复的大鼠,同样方法注射Kv通道拮抗剂4-AP又可以显著降低面部痛阈。以上结果表明,BKCa通道激动剂NS1619和Kv通道拮抗剂4-AP可以显著影响ION-CCI大鼠的面部机械痛阈,提示激活BKCa通道可以抑制由ION-CCI引起的三叉神经病理性痛,而激活Kv通道可能对ION-CCI引起的三叉神经病理痛有紧张性的抑制作用。展开更多
Based on the molecular recognition ability of conductive polymer and the peculiar properties of carbon nanotubes,a novel single wall nanotubes(SWNTs)compound poly(4-aminopyridine)modified electrode(SWNTs/POAPE)is prep...Based on the molecular recognition ability of conductive polymer and the peculiar properties of carbon nanotubes,a novel single wall nanotubes(SWNTs)compound poly(4-aminopyridine)modified electrode(SWNTs/POAPE)is prepared at glass carbon electrode(GCE).The electrochemistry response of nitrophenol isomers is studied at the SWNTs/POAPE.The re-sult indicates that o-,m-and p-nitrophenol are separated entirely at the SWNTs/POAPE interface.The electrode present here can be easily used to determine nitrophenol isomers simultaneously with higher sensitivity.展开更多
Most axons in the vertebral central nervous system are myelinated by oligodendrocytes.Myelin protects and insulates neuronal processes,enabling the fast,saltatory conduction unique to myelinated axons.Myelin disruptio...Most axons in the vertebral central nervous system are myelinated by oligodendrocytes.Myelin protects and insulates neuronal processes,enabling the fast,saltatory conduction unique to myelinated axons.Myelin disruption resulting from trauma and biochemical reaction is a common pathological event in spinal cord injury and chronic neurodegenerative diseases.Myelin damage-induced axonal conduction block is considered to be a significant contributor to the devastating neurological deficits resulting from trauma and illness.Potassium channels are believed to play an important role in axonal conduction failure in spinal cord injury and multiple sclerosis.Myelin damage has been shown to unmask potassium channels,creating aberrant potassium currents that inhibit conduction.Potassium channel blockade reduces this ionic leakage and improves conduction.The present review was mainly focused on the development of this technique of restoring axonal conduction and neurological function of demyelinated axons.The drug 4-aminopyridine has recently shown clinical success in treating multiple sclerosis symptoms.Further translational research has also identified several novel potassium channel blockers that may prove effective in restoring axonal conduction.展开更多
基金supported by grants from the National Institutes of Health,USA(No.K08 AR060164-01A)Department of Defense,USA(Nos.W81XWH-16-1-0725 and W81XWH-19-1-0773)in addition to institutional support from the Pennsylvania State University College of Medicine。
文摘We recently demonstrated a repurposing beneficial effect of 4-aminopyridine(4-AP),a potassium channel blocker,on functional recove ry and muscle atrophy after sciatic nerve crush injury in rodents.However,this effect of 4-AP is unknown in nerve transection,gap,and grafting models.To evaluate and compare the functional recovery,nerve morphology,and muscle atrophy,we used a novel stepwise nerve transection with gluing(STG),as well as 7-mm irreparable nerve gap(G-7/0)and 7-mm isografting in 5-mm gap(G-5/7)models in the absence and presence of 4-AP treatment.Following surgery,sciatic functional index was determined wee kly to evaluate the direct in vivo global motor functional recovery.After 12 weeks,nerves were processed for whole-mount immunofluorescence imaging,and tibialis anterior muscles were harvested for wet weight and quantitative histomorphological analyses for muscle fiber crosssectional area and minimal Feret's diameter.Average post-injury sciatic functional index values in STG and G-5/7 models were significantly greater than those in the G-7/0 model.4-AP did not affect the sciatic functional index recovery in any model.Compared to STG,nerve imaging revealed more misdirected axons and distorted nerve architecture with isografting.While muscle weight,cross-sectional area,and minimal Feret's diameter were significantly smaller in G-7/0 model compared with STG and G-5/7,4-AP treatment significantly increased right TA muscle mass,cross-sectional area,and minimal Feret's diameter in G-7/0 model.These findings demonstrate that functional recovery and muscle atrophy after peripheral nerve injury are directly related to the intervening nerve gap,and 4-AP exerts diffe rential effects on functional recove ry and muscle atrophy.
基金supported by grants from the National Institutes of Health(K08 AR060164-01A)Department of Defense(W81XWH-16-1-0725)to JCE in addition to institutional support from the University of Rochester and Pennsylvania State University Medical Centers
文摘Oral 4-aminopyridine(4-AP)is clinically used for symptomatic relief in multiple sclerosis and we recently demonstrated that systemic 4-AP had previously unknown clinically-relevant effects after traumatic peripheral nerve injury including the promotion of re-myelination,improvement of nerve conductivity,and acceleration of functional recovery.We hypothesized that,instead of oral or injection administration,transdermal 4-AP(TD-4-AP)could also improve functional recovery after traumatic peripheral nerve injury.Mice with surgical traumatic peripheral nerve injury received TD-4AP or vehicle alone and were examined for skin permeability,pharmacokinetics,functional,electrophysiological,and nerve morphological properties.4-AP showed linear pharmacokinetics and the maximum plasma 4-AP concentrations were proportional to TD-4-AP dose.While a single dose of TD-4-AP administration demonstrated rapid transient improvement in motor function,chronic TD-4-AP treatment significantly improved motor function and nerve conduction and these effects were associated with fewer degenerating axons and thicker myelin sheaths than those from vehicle controls.These findings provide direct evidence for the potential transdermal applicability of 4-AP and demonstrate that 4-AP delivered through the skin can enhance in-vivo functional recovery and nerve conduction while decreasing axonal degeneration.The animal experiments were approved by the University Committee on Animal Research(UCAR)at the University of Rochester(UCAR-2009-019)on March 31,2017.
基金supported by grants from the National Institutes of Health(NIHK08 AR060164-01A)+2 种基金the Department of Defense(DoDW81XWH-16-1-0725)to JCEinstitutional support from the University of Rochester and Pennsylvania State University Medical Centers。
文摘4-Aminopyridine(4-AP), an FDA-approved drug for the symptomatic treatment of multiple sclerosis, is used to improve neuromuscular function in patients with diverse demyelinating disorders. We recently demonstrated that local, transdermal or injectable forms of 4-AP improve myelination, nerve conduction velocity, muscle atrophy, and motor function after traumatic peripheral nerve injury in mice. While oral 4-AP is most commonly used in the clinic, it is unknown whether human equivalent oral doses of 4-AP have effects on traumatic peripheral nerve injury differentiation, myelination, muscle atrophy, functional recovery, and post-injury inflammatory processes in animals. Mice with sciatic nerve crush or denervation injury received oral or intraperitoneal 4-AP(10 μg) or vehicle alone and were examined for pharmacokinetics, motor function, muscle mass, intrinsic muscle force, nerve morphological and gene expression profiles. 4-AP showed linear pharmacokinetics and the maximum plasma 4-AP concentrations were proportional to 4-AP dose. Acute single dose of oral 4-AP administration induced a rapid transient improvement in motor function that was different in traumatic peripheral nerve injury with or without nerve continuity, chronic daily oral 4-AP treatment significantly enhanced post crush injury motor function recovery and this effect was associated with improved myelination, muscle mass, and ex vivo muscle force. Polymerase chain reaction array analysis with crushed nerve revealed significant alterations in gene involved in axonal inflammation and regeneration. These findings provide convincing evidence that regardless of the route of administration, 4-AP can acutely differentiate traumatic peripheral nerve injury with or without nerve continuity and can enhance in vivo functional recovery with better preservation of myelin sheaths, muscle mass, and muscle force. The animal experiments were approved by the University Committee on Animal Research(UCAR) at the University of Rochester(UCAR-2009-019) on March 31, 2017.
基金supported by the Innovation Program for Highlevel Talents of Guizhou Province (No. 2016-5657)the University of Hull for support。
文摘The binding interactions between 4-aminopyridine(4-AP) and a series of cucurbit[n]urils(Q[5], Q[6],TMe Q[6], Q[7], Q[8]) have been studied using1H NMR spectroscopy, UV–vis absorption spectroscopy,isothermal titration calorimetry(ITC) and X-ray crystallography. The data indicates that the Q[5]@4-AP complex exhibits exo binding, which is not observed in the other four host-guest complexes. Furthermore,X-ray crystallography clearly reveals how the Q[n]s bind with 4-AP to form complexes, for example Q[5]forms an outer-surface complex, whilst Q[6], TMe Q[6] and Q[7] formed 1:1 host and guest type complexes, and Q[8] formed a stable 1:2 ternary complex due to its large cavity, which can accommodate two 4-AP molecules.
基金supported by the Basic Research Program of Science and Technology Commission of Shanghai MunicipalityChina(No.08JC1405400)
文摘三叉神经痛(trigeminal neuralgia)是临床上的顽疾,长期以来为医学界所重视,但其发病机制尚不清晰,临床上也无有效的治疗方法。本研究首先通过免疫荧光化学法和动物行为学测定,对经眶下孔达三叉神经节目标注射给药法的效果进行了评价,然后行眶下神经慢性缩窄环术(chronic constriction injury of the infraorbital nerve,ION-CCI)建立三叉神经病理性痛大鼠模型,用经眶下孔达三叉神经节目标注射法分别注射BKCa通道激动剂NS1619和Kv通道拮抗剂4-AP,观察药物对大鼠面部机械痛阈的影响。结果显示,通过经眶下孔达三叉神经节目标注射法,药物可以准确到达三叉神经节,并产生了比一般眶下孔注射给药法更为持久的注射效果。ION-CCI术后第6天大鼠术侧面部触须垫部产生了显著的异常性疼痛(allodynia),并可以维持到至少术后第42天。在ION-CCI术后第15天大鼠,运用经眶下孔达三叉神经节目标注射法注射BKCa通道激动剂NS1619可以剂量依赖性地显著提高ION-CCI组大鼠的面部机械痛阈,逆转面部痛觉过敏;而在ION-CCI术后第35天痛阈部分恢复的大鼠,同样方法注射Kv通道拮抗剂4-AP又可以显著降低面部痛阈。以上结果表明,BKCa通道激动剂NS1619和Kv通道拮抗剂4-AP可以显著影响ION-CCI大鼠的面部机械痛阈,提示激活BKCa通道可以抑制由ION-CCI引起的三叉神经病理性痛,而激活Kv通道可能对ION-CCI引起的三叉神经病理痛有紧张性的抑制作用。
基金the Natural Science Foundation of Henan Province,China(Grant No.0311021000)the Key Laboratory of Environmental Science and Engineering,Education Commission of Henan Province.
文摘Based on the molecular recognition ability of conductive polymer and the peculiar properties of carbon nanotubes,a novel single wall nanotubes(SWNTs)compound poly(4-aminopyridine)modified electrode(SWNTs/POAPE)is prepared at glass carbon electrode(GCE).The electrochemistry response of nitrophenol isomers is studied at the SWNTs/POAPE.The re-sult indicates that o-,m-and p-nitrophenol are separated entirely at the SWNTs/POAPE interface.The electrode present here can be easily used to determine nitrophenol isomers simultaneously with higher sensitivity.
基金supported by the Purdue Research Foundation(No. 61133)National Institute of Health,USA(No.1R21 NS050174-01A1)
文摘Most axons in the vertebral central nervous system are myelinated by oligodendrocytes.Myelin protects and insulates neuronal processes,enabling the fast,saltatory conduction unique to myelinated axons.Myelin disruption resulting from trauma and biochemical reaction is a common pathological event in spinal cord injury and chronic neurodegenerative diseases.Myelin damage-induced axonal conduction block is considered to be a significant contributor to the devastating neurological deficits resulting from trauma and illness.Potassium channels are believed to play an important role in axonal conduction failure in spinal cord injury and multiple sclerosis.Myelin damage has been shown to unmask potassium channels,creating aberrant potassium currents that inhibit conduction.Potassium channel blockade reduces this ionic leakage and improves conduction.The present review was mainly focused on the development of this technique of restoring axonal conduction and neurological function of demyelinated axons.The drug 4-aminopyridine has recently shown clinical success in treating multiple sclerosis symptoms.Further translational research has also identified several novel potassium channel blockers that may prove effective in restoring axonal conduction.
