MicroRNA-124 contributes to neurogenesis through regulating its targets, but its expression both in the brain of Huntington＇s disease mouse models and patients is decreased. However, the effects of microRNA-124 on th...MicroRNA-124 contributes to neurogenesis through regulating its targets, but its expression both in the brain of Huntington＇s disease mouse models and patients is decreased. However, the effects of microRNA-124 on the progression of Huntington＇s disease have not been reported. Results from this study showed that microRNA-124 increased the latency to fall for each R6/2 Hunting- ton＇s disease transgenic mouse in the rotarod test. 5-Bromo-2＇-deoxyuridine （BrdU） staining of the striatum shows an increase in neurogenesis. In addition, brain-derived neurotrophic factor and peroxisome proliferator-activated receptor gamma coactivator 1-alpha protein levels in the striatum were increased and SRY-related HMG box transcription factor 9 protein level was de- creased. These findings suggest that microRNA-124 slows down the progression of Huntington＇s disease possibly through its important role in neuronal differentiation and survival.展开更多
Paralysis following spinal cord injury （SCI） is due to failure of axonal regeneration. It is believed that the capacities of neurons to regrow their axons are due partly to their intrinsic characteristics, which in ...Paralysis following spinal cord injury （SCI） is due to failure of axonal regeneration. It is believed that the capacities of neurons to regrow their axons are due partly to their intrinsic characteristics, which in turn are greatly influenced by several types of inhibitory molecules that are present, or even increased in the extracellular environment of the injured spinal cord. Many of these inhibitory molecules have been studied extensively in recent years. It has been suggested that the small GTPase RhoA is an intracellular convergence point for signaling by these extracellular inhibitory molecules, but due to the complexity of the central nervous system （CNS） in mammals, and the limitation of pharmacological tools, the specific roles of RhoA are unclear. By exploiting the anatomical and technical advantages of the lamprey CNS, we recently demonstrated that RhoA knockdown promotes true axon regeneration through the lesion site after SCI. In addition, we found that RhoA knockdown protects the large, identified reticulospinal neurons from apoptosis after their axons were axotomized in spinal cord. Therefore, manipulation of the RhoA signaling pathway may be an important approach in the development of treatments that are both neuroprotective and axon regeneration-promoting, to enhance functional recovery after SCI.展开更多
Although alpha-synuclein is generally thought to have a pathological role in Parkinson＇s disease, accumulative evidence exists that alpha-synuclein has a neuroprotective effect. The aim of this study was to evaluate ...Although alpha-synuclein is generally thought to have a pathological role in Parkinson＇s disease, accumulative evidence exists that alpha-synuclein has a neuroprotective effect. The aim of this study was to evaluate the effect of extracellular alpha-synuclein on dopaminergic cell survival. We assessed cell viability using the 3-（4,5-dimethyt-thiazol-2-yt）-2,5-diphenyltertazolium bromide （MTT） assay both in undifferentiated SH-SY5Y （SHSY） cells and neuronally-differentiated SH-SY5Y （ndSHSY） cells after 24 hour treatment with monomeric alpha-synuclein at various concentrations （0 [control], 50, 100 nmol/L, 1 IJmol/L）. To determine whether cell viability assessed by MTT assay was affected by cell proliferation, 5-bromo-2＇-deoxyuridine （BrdU） incorporation assay was per- formed. Level of both Akt and phosphorylated Akt was measured using western blot method in ndSHSY cells with or without 24 hour alpha-synuclein treatment. Cell viability was increased in ndSHSY cells at the nanomolar concentration of alpha-synuclein, but not in SHSY cells. Proportion of BrdU-positive ndSHSY cells was decreased in alpha-synuclein-treated group compared with control group. Level of phosphorylated Akt in alpha-synuclein-treated group was higher compared with the control group. Our study shows that extracellular alpha-synuclein at nanomolar concentra- tion benefits dopaminergic cell survival via Akt pathway.展开更多
Oxidative stress contributes to the pathogenesis of neurodegenerative diseases.With the aim to find reagents that reduce oxidative stress,a phage display library was screened for peptides mimicking a2,6-sialyllactose(...Oxidative stress contributes to the pathogenesis of neurodegenerative diseases.With the aim to find reagents that reduce oxidative stress,a phage display library was screened for peptides mimicking a2,6-sialyllactose(6'-SL),which is known to beneficially influence neural functions.Using Sambucus nigra lectin,which specifically binds to 6'-SL,we screened a phage display library and found a peptide comprising identical sequences of 12 amino acids.Mimetic peptide,reverse peptide and scrambled peptide were tested for inhibition of 6'-SL binding to the lectin.Indeed,lectin binding to 6'-SL was inhibited by the most frequently identified mimetic peptide,but not by the reverse or scrambled peptides,showing that this peptide mimics 6'-SL.Functionally,mimetic peptide,but not the reverse or scrambled peptides,increased viability and expression of neural cell adhesion molecule L1 in SK-N-SH human neuroblastoma cells,and promoted survival and neurite outgrowth of cultured mouse cerebellar granule neurons challenged by H_20_2-induced oxidative stress.The combined results indicate that the 6'-SL mimetic peptide promotes neuronal survival and neuritogenesis,thus raising hopes for the treatment of neurodegenerative diseases.This study was approved by the Medical Ethics Committee of Shantou University Medical College,China(approval No.SUMC 2014-004)on February 20,2014.展开更多
盐诱导激酶(salt-inducible kinase,SIK)是属于单磷酸腺苷激活蛋白激酶/蔗糖非酵解1(adenosine monophosphate-activated protein kinase and sucrose non-fermenting 1,AMPK/SNF1)家族的丝氨酸/苏氨酸蛋白激酶。SIK自1998年被发现以来...盐诱导激酶(salt-inducible kinase,SIK)是属于单磷酸腺苷激活蛋白激酶/蔗糖非酵解1(adenosine monophosphate-activated protein kinase and sucrose non-fermenting 1,AMPK/SNF1)家族的丝氨酸/苏氨酸蛋白激酶。SIK自1998年被发现以来,越来越多的功能被人们证实和认可。现已发现,SIK在能量代谢、细胞信号转导、细胞周期、肿瘤、黑素原生成等诸多方面有重要作用。通过查阅近些年相关文献,在此重点总结一下SIK2功能的研究进展。展开更多
基金supported by a grant(A121911 and HI14C2348)of the Korean Health Technology R&D Project,Ministry of Health&WelfareNational Research Foundation of Korea(NRF)(2011-0012728 and 2014R1A2A1A11051520)
文摘MicroRNA-124 contributes to neurogenesis through regulating its targets, but its expression both in the brain of Huntington＇s disease mouse models and patients is decreased. However, the effects of microRNA-124 on the progression of Huntington＇s disease have not been reported. Results from this study showed that microRNA-124 increased the latency to fall for each R6/2 Hunting- ton＇s disease transgenic mouse in the rotarod test. 5-Bromo-2＇-deoxyuridine （BrdU） staining of the striatum shows an increase in neurogenesis. In addition, brain-derived neurotrophic factor and peroxisome proliferator-activated receptor gamma coactivator 1-alpha protein levels in the striatum were increased and SRY-related HMG box transcription factor 9 protein level was de- creased. These findings suggest that microRNA-124 slows down the progression of Huntington＇s disease possibly through its important role in neuronal differentiation and survival.
基金supported by R01-NS092876(NIH,MES,PI)SHC-85400(Shriners Research Foundation,MES,PI)+1 种基金SHC-85220(Shriners Research Foundation,MES,PI)SHC-84293(Shriners Research Foundation,JH,PI)
文摘Paralysis following spinal cord injury （SCI） is due to failure of axonal regeneration. It is believed that the capacities of neurons to regrow their axons are due partly to their intrinsic characteristics, which in turn are greatly influenced by several types of inhibitory molecules that are present, or even increased in the extracellular environment of the injured spinal cord. Many of these inhibitory molecules have been studied extensively in recent years. It has been suggested that the small GTPase RhoA is an intracellular convergence point for signaling by these extracellular inhibitory molecules, but due to the complexity of the central nervous system （CNS） in mammals, and the limitation of pharmacological tools, the specific roles of RhoA are unclear. By exploiting the anatomical and technical advantages of the lamprey CNS, we recently demonstrated that RhoA knockdown promotes true axon regeneration through the lesion site after SCI. In addition, we found that RhoA knockdown protects the large, identified reticulospinal neurons from apoptosis after their axons were axotomized in spinal cord. Therefore, manipulation of the RhoA signaling pathway may be an important approach in the development of treatments that are both neuroprotective and axon regeneration-promoting, to enhance functional recovery after SCI.
基金supported by the Seoul National University Hospital(SNUH)Research Fund,No.03-2010-0240
文摘Although alpha-synuclein is generally thought to have a pathological role in Parkinson＇s disease, accumulative evidence exists that alpha-synuclein has a neuroprotective effect. The aim of this study was to evaluate the effect of extracellular alpha-synuclein on dopaminergic cell survival. We assessed cell viability using the 3-（4,5-dimethyt-thiazol-2-yt）-2,5-diphenyltertazolium bromide （MTT） assay both in undifferentiated SH-SY5Y （SHSY） cells and neuronally-differentiated SH-SY5Y （ndSHSY） cells after 24 hour treatment with monomeric alpha-synuclein at various concentrations （0 [control], 50, 100 nmol/L, 1 IJmol/L）. To determine whether cell viability assessed by MTT assay was affected by cell proliferation, 5-bromo-2＇-deoxyuridine （BrdU） incorporation assay was per- formed. Level of both Akt and phosphorylated Akt was measured using western blot method in ndSHSY cells with or without 24 hour alpha-synuclein treatment. Cell viability was increased in ndSHSY cells at the nanomolar concentration of alpha-synuclein, but not in SHSY cells. Proportion of BrdU-positive ndSHSY cells was decreased in alpha-synuclein-treated group compared with control group. Level of phosphorylated Akt in alpha-synuclein-treated group was higher compared with the control group. Our study shows that extracellular alpha-synuclein at nanomolar concentra- tion benefits dopaminergic cell survival via Akt pathway.
基金supported by the National Basic Research Development Program of China(No.2006CB5008052007CB512205)+4 种基金the National Natural Science Foundation of China(No.308708033093003430900427)Pujiang Talent Project of the Shanghai Scienceand Technology Committee(No.08PJ14016)the 211 Project of the Ministry of Education of China
基金supported by the National Natural Science Foundation of China,No.81471279 and No.81171138(to WJZ)Talent Support Grant from Shantou University Medical College,China,No.2501220118(to WJZ)the Li Kashing Foundation,No.LD030302(to MS)
文摘Oxidative stress contributes to the pathogenesis of neurodegenerative diseases.With the aim to find reagents that reduce oxidative stress,a phage display library was screened for peptides mimicking a2,6-sialyllactose(6'-SL),which is known to beneficially influence neural functions.Using Sambucus nigra lectin,which specifically binds to 6'-SL,we screened a phage display library and found a peptide comprising identical sequences of 12 amino acids.Mimetic peptide,reverse peptide and scrambled peptide were tested for inhibition of 6'-SL binding to the lectin.Indeed,lectin binding to 6'-SL was inhibited by the most frequently identified mimetic peptide,but not by the reverse or scrambled peptides,showing that this peptide mimics 6'-SL.Functionally,mimetic peptide,but not the reverse or scrambled peptides,increased viability and expression of neural cell adhesion molecule L1 in SK-N-SH human neuroblastoma cells,and promoted survival and neurite outgrowth of cultured mouse cerebellar granule neurons challenged by H_20_2-induced oxidative stress.The combined results indicate that the 6'-SL mimetic peptide promotes neuronal survival and neuritogenesis,thus raising hopes for the treatment of neurodegenerative diseases.This study was approved by the Medical Ethics Committee of Shantou University Medical College,China(approval No.SUMC 2014-004)on February 20,2014.
文摘盐诱导激酶(salt-inducible kinase,SIK)是属于单磷酸腺苷激活蛋白激酶/蔗糖非酵解1(adenosine monophosphate-activated protein kinase and sucrose non-fermenting 1,AMPK/SNF1)家族的丝氨酸/苏氨酸蛋白激酶。SIK自1998年被发现以来,越来越多的功能被人们证实和认可。现已发现,SIK在能量代谢、细胞信号转导、细胞周期、肿瘤、黑素原生成等诸多方面有重要作用。通过查阅近些年相关文献,在此重点总结一下SIK2功能的研究进展。
