Amyotrophic lateral syndrome(ALS)is a progressive degenerative disorder characterized by motor neuron death and axon degeneration.Mitochondrial dysfunction plays a key role in the pathogenesis of ALS,the mechanism of ...Amyotrophic lateral syndrome(ALS)is a progressive degenerative disorder characterized by motor neuron death and axon degeneration.Mitochondrial dysfunction plays a key role in the pathogenesis of ALS,the mechanism of which remains poorly understood.The B-cell lymphoma-2(Bcl-2)family of proteins that control and mediate mitochondrial function and apoptosis,including the pro-apoptotic members Bcl2-Associated X(Bax),are involved in ALS development.The death receptor 6(DR6)regulates motor neuron death in ALS,and DR6 antibodies can prevent axon degeneration and motor neuron damage by blocking DR6.Previous studies demonstrated that PSAP localized to mitochondria and was required for DR6-induced apoptosis.In this study,SOD1^(G93A) was transfected into the motor neuron cell line NSC-34 to serve as an ALS cell model in vitro.The data assessed the role of PSAP in SOD1^(G93A)induced apoptosis and demonstrated that the overexpression of SOD1^(G93A),but not wtSOD1,induced PARP cleavage,caspase-3 activation,cytochrome c release,and Bax translocation.PSAP,Bax,and Bak were necessary for SOD1^(G93A)induced apoptosis,as silencing PSAP inhibited SOD1^(G93A)-mediated cell death that was dependent on Bax-Bak interaction.展开更多
Heterogenous nuclear ribonucleoprotein G is down-regulated in the spinal cord of the Tg(SOD1*G93A)1Gur(TG)amyotrophic lateral sclerosis mouse model.However,most studies have only examined heterogenous nuclear ribonucl...Heterogenous nuclear ribonucleoprotein G is down-regulated in the spinal cord of the Tg(SOD1*G93A)1Gur(TG)amyotrophic lateral sclerosis mouse model.However,most studies have only examined heterogenous nuclear ribonucleoprotein G expression in the amyotrophic lateral sclerosis model and heterogenous nuclear ribonucleoprotein G effects in amyotrophic lateral sclerosis pathogenesis such as in apoptosis are unknown.In this study,we studied the potential mechanism of heterogenous nuclear ribonucleoprotein G in neuronal death in the spinal cord of TG and wild-type mice and examined the mechanism by which heterogenous nuclear ribonucleoprotein G induces apoptosis.Heterogenous nuclear ribonucleoprotein G in spinal cord was analyzed using immunohistochemistry and western blotting,and cell proliferation and proteins(TAR DNA binding protein 43,superoxide dismutase 1,and Bax)were detected by the Cell Counting Kit-8 and western blot analysis in heterogenous nuclear ribonucleoprotein G siRNA-transfected PC12 cells.We analyzed heterogenous nuclear ribonucleoprotein G distribution in spinal cord in the amyotrophic lateral sclerosis model at various time points and the expressions of apoptosis and proliferation-related proteins.Heterogenous nuclear ribonucleoprotein G was mainly localized in neurons.Amyotrophic lateral sclerosis mice were examined at three stages:preonset(60-70 days),onset(90-100 days)and progression(120-130 days).The number of heterogenous nuclear ribonucleoprotein G-positive cells was significantly higher in the anterior horn of the lumbar spinal cord segment of TG mice at the preonset stage than that of control group but lower than that of the control group at the onset stage.The number of heterogenous nuclear ribonucleoprotein G-positive cells in both central canal and surrounding gray matter of the whole spinal cord of TG mice at the onset stage was significantly lower than that in the control group,whereas that of the lumbar spinal cord segment of TG mice was significantly higher than that in the control group at preonset stage and significantly lower than that in the control group at the progression stage.The numbers of heterogenous nuclear ribonucleoprotein G-positive cells in the posterior horn of cervical and thoracic segments of TG mice at preonset and progression stages were significantly lower than those in the control group.The expression of heterogenous nuclear ribonucleoprotein G in the cervical spinal cord segment of TG mice was significantly higher than that in the control group at the preonset stage but significantly lower at the progression stage.The expression of heterogenous nuclear ribonucleoprotein G in the thoracic spinal cord segment of TG mice was significantly increased at the preonset stage,significantly decreased at the onset stage,and significantly increased at the progression stage compared with the control group.heterogenous nuclear ribonucleoprotein G expression in the lumbar spinal cord segment of TG mice was significantly lower than that of the control group at the progression stage.After heterogenous nuclear ribonucleoprotein G gene silencing,PC12 cell survival was lower than that of control cells.Both TAR DNA binding protein 43 and Bax expressions were significantly increased in heterogenous nuclear ribonucleoprotein G-silenced cells compared with control cells.Our study suggests that abnormal distribution and expression of heterogenous nuclear ribonucleoprotein G might play a protective effect in amyotrophic lateral sclerosis development via preventing neuronal death by reducing abnormal TAR DNA binding protein 43 generation in the spinal cord.展开更多
The development of amyotrophic lateral sclerosis(ALS)may be related to the abnormal alterations of multiple proteins.Our previous study revealed that the expression of phosphoinositide-3-kinase regulatory subunit 4(PI...The development of amyotrophic lateral sclerosis(ALS)may be related to the abnormal alterations of multiple proteins.Our previous study revealed that the expression of phosphoinositide-3-kinase regulatory subunit 4(PIK3R4)was decreased in ALS.However,the role of PIK3R4 in ALS pathogenesis remains unknown.This study was the first to find that transfection of PC12 cells with small interfering RNA against the PIK3R4 gene significantly decreased the expression levels of PIK3R4 and the autophagy-related proteins p62 and LC3.Additionally,in vivo experiments revealed that the PIK3R4 protein was extensively expressed in the anterior horn,posterior horn,central canal,and areas surrounding the central canal in cervical,thoracic,and lumbar segments of the spinal cord in adult mice.PIK3R4 protein was mainly expressed in the neurons within the spinal lumbar segments.PIK3R4 and p62 expression levels were significantly decreased at both the pre-onset and onset stages of ALS disease in Tg(SOD1*G93A)1 Gur mice compared with control mice,but these proteins were markedly increased at the progression stage.LC3 protein expression did not change during progression of ALS.These findings suggest that PIK3R4 likely participates in the prevention of ALS progression.This study was approved by the Ethics Committee for Animal Care and Use of Jiangxi Provincial People’s Hospital,Affiliated People’s Hospital of Nanchang University(approval No.2020025)on March 26,2020.展开更多
Background:Neuron-microglia communication plays a crucial role in the motor neurons(MNs)death in amyotrophic lateral sclerosis(ALS).Neurons can express chemokine(C-X3-C motif)ligand 1(CX3CL1),which mediates microglial...Background:Neuron-microglia communication plays a crucial role in the motor neurons(MNs)death in amyotrophic lateral sclerosis(ALS).Neurons can express chemokine(C-X3-C motif)ligand 1(CX3CL1),which mediates microglial activation via interacting with its sole receptor CX3CR1 in microglia.In the present study,we aimed to investigate the dynamic changes of CX3CL1/CX3CR1 axis during microglial activation and MNs loss in SOD1G93A mouse model of ALS.Methods:qPCR,western blot and immunofluorescent staining were used to examine the mRNA and protein levels and localization of CX3CL1/CX3CR1 in the anterior horn region of spinal cord in both SOD1G93A mice and their agematched wild type(WT)littermates at 40,60,90 and 120 days of age.The M1/M2 microglial activation in the spinal cord tissues of SOD1G93A mice and WT mice were evaluated by immunofluorescent staining of M1/M2 markers and further confirmed by qPCR analysis of M1/M2-related cytokines.Results:The immunofluorescent staining revealed that CX3CL1 was predominately expressed in MNs,while CX3CR1 was highly expressed in microglia in the anterior horn region of spinal cord.Compared with age-matched WT mice,CX3CL1 mRNA level was elevated at 40 days but decreased at 90 and 120 days in the anterior horn region of spinal cords in ALS mice.Consistently,CX3CR1 mRNA level was increased at 90 and 120 days.Western blot assay further confirmed the dynamic changes of CX3CL1/CX3CR1 axis in ALS mice.Additionally,the levels of M1/M2 markers of microglia and their related cytokines in the anterior horn region of spinal cord in ALS mice were increased at 90 and 120 days.Moreover,while M1-related cytokines in ALS mice were persistently increased at 120 days,the upregulated M2-related cytokines started to decline at 120 days,suggesting an altered microglial activation.Conclusions:Our data revealed the dynamic changes of CX3CL1/CX3CR1 axis and an imbalanced M1/M2 microglial activation during ALS pathological progression.These findings may help identify potential molecular targets for ALS therapy.展开更多
基金supported by grants from the National Natural Science Foundation of China[Grant No.81701076,Linlin Zeng]the Science and Technology Department of Jilin Province[Grant No.20190701037GH,Fuqiang Zhang+2 种基金Grant No.20190701036GH,Linlin Zengand Grant No.20200201386JC,Guodong Li]the Education Department of Jilin Province[Grant No.JJKH20200948KJ,Linlin Zeng]。
文摘Amyotrophic lateral syndrome(ALS)is a progressive degenerative disorder characterized by motor neuron death and axon degeneration.Mitochondrial dysfunction plays a key role in the pathogenesis of ALS,the mechanism of which remains poorly understood.The B-cell lymphoma-2(Bcl-2)family of proteins that control and mediate mitochondrial function and apoptosis,including the pro-apoptotic members Bcl2-Associated X(Bax),are involved in ALS development.The death receptor 6(DR6)regulates motor neuron death in ALS,and DR6 antibodies can prevent axon degeneration and motor neuron damage by blocking DR6.Previous studies demonstrated that PSAP localized to mitochondria and was required for DR6-induced apoptosis.In this study,SOD1^(G93A) was transfected into the motor neuron cell line NSC-34 to serve as an ALS cell model in vitro.The data assessed the role of PSAP in SOD1^(G93A)induced apoptosis and demonstrated that the overexpression of SOD1^(G93A),but not wtSOD1,induced PARP cleavage,caspase-3 activation,cytochrome c release,and Bax translocation.PSAP,Bax,and Bak were necessary for SOD1^(G93A)induced apoptosis,as silencing PSAP inhibited SOD1^(G93A)-mediated cell death that was dependent on Bax-Bak interaction.
基金supported by the National Natural Science Foundation of China,Nos.30560042,81160161,81360198,82160255Education Department of Jiangxi Province,Nos.GJJ13198 and GJJ170021+1 种基金Jiangxi Provincial Department of Science and Technology,Nos.[2014]-47,20142BBG70062,20171BAB215022,20192BAB205043Health and Family Planning Commission of Jiangxi Province,No.20181019(all to RSX).
文摘Heterogenous nuclear ribonucleoprotein G is down-regulated in the spinal cord of the Tg(SOD1*G93A)1Gur(TG)amyotrophic lateral sclerosis mouse model.However,most studies have only examined heterogenous nuclear ribonucleoprotein G expression in the amyotrophic lateral sclerosis model and heterogenous nuclear ribonucleoprotein G effects in amyotrophic lateral sclerosis pathogenesis such as in apoptosis are unknown.In this study,we studied the potential mechanism of heterogenous nuclear ribonucleoprotein G in neuronal death in the spinal cord of TG and wild-type mice and examined the mechanism by which heterogenous nuclear ribonucleoprotein G induces apoptosis.Heterogenous nuclear ribonucleoprotein G in spinal cord was analyzed using immunohistochemistry and western blotting,and cell proliferation and proteins(TAR DNA binding protein 43,superoxide dismutase 1,and Bax)were detected by the Cell Counting Kit-8 and western blot analysis in heterogenous nuclear ribonucleoprotein G siRNA-transfected PC12 cells.We analyzed heterogenous nuclear ribonucleoprotein G distribution in spinal cord in the amyotrophic lateral sclerosis model at various time points and the expressions of apoptosis and proliferation-related proteins.Heterogenous nuclear ribonucleoprotein G was mainly localized in neurons.Amyotrophic lateral sclerosis mice were examined at three stages:preonset(60-70 days),onset(90-100 days)and progression(120-130 days).The number of heterogenous nuclear ribonucleoprotein G-positive cells was significantly higher in the anterior horn of the lumbar spinal cord segment of TG mice at the preonset stage than that of control group but lower than that of the control group at the onset stage.The number of heterogenous nuclear ribonucleoprotein G-positive cells in both central canal and surrounding gray matter of the whole spinal cord of TG mice at the onset stage was significantly lower than that in the control group,whereas that of the lumbar spinal cord segment of TG mice was significantly higher than that in the control group at preonset stage and significantly lower than that in the control group at the progression stage.The numbers of heterogenous nuclear ribonucleoprotein G-positive cells in the posterior horn of cervical and thoracic segments of TG mice at preonset and progression stages were significantly lower than those in the control group.The expression of heterogenous nuclear ribonucleoprotein G in the cervical spinal cord segment of TG mice was significantly higher than that in the control group at the preonset stage but significantly lower at the progression stage.The expression of heterogenous nuclear ribonucleoprotein G in the thoracic spinal cord segment of TG mice was significantly increased at the preonset stage,significantly decreased at the onset stage,and significantly increased at the progression stage compared with the control group.heterogenous nuclear ribonucleoprotein G expression in the lumbar spinal cord segment of TG mice was significantly lower than that of the control group at the progression stage.After heterogenous nuclear ribonucleoprotein G gene silencing,PC12 cell survival was lower than that of control cells.Both TAR DNA binding protein 43 and Bax expressions were significantly increased in heterogenous nuclear ribonucleoprotein G-silenced cells compared with control cells.Our study suggests that abnormal distribution and expression of heterogenous nuclear ribonucleoprotein G might play a protective effect in amyotrophic lateral sclerosis development via preventing neuronal death by reducing abnormal TAR DNA binding protein 43 generation in the spinal cord.
基金supported by the National Natural Science Foundation of China(Nos.30560042,81160161 and 81360198)Education Department of Jiangxi Province(No.GJJ170021)+1 种基金Jiangxi Provincial Department of Science and Technology(Nos.[2014]-47,20142BBG70062,20171BAB215022,20192BAB205043)Health Commission of Jiangxi Province(No.20181019)(all to RSX)。
文摘The development of amyotrophic lateral sclerosis(ALS)may be related to the abnormal alterations of multiple proteins.Our previous study revealed that the expression of phosphoinositide-3-kinase regulatory subunit 4(PIK3R4)was decreased in ALS.However,the role of PIK3R4 in ALS pathogenesis remains unknown.This study was the first to find that transfection of PC12 cells with small interfering RNA against the PIK3R4 gene significantly decreased the expression levels of PIK3R4 and the autophagy-related proteins p62 and LC3.Additionally,in vivo experiments revealed that the PIK3R4 protein was extensively expressed in the anterior horn,posterior horn,central canal,and areas surrounding the central canal in cervical,thoracic,and lumbar segments of the spinal cord in adult mice.PIK3R4 protein was mainly expressed in the neurons within the spinal lumbar segments.PIK3R4 and p62 expression levels were significantly decreased at both the pre-onset and onset stages of ALS disease in Tg(SOD1*G93A)1 Gur mice compared with control mice,but these proteins were markedly increased at the progression stage.LC3 protein expression did not change during progression of ALS.These findings suggest that PIK3R4 likely participates in the prevention of ALS progression.This study was approved by the Ethics Committee for Animal Care and Use of Jiangxi Provincial People’s Hospital,Affiliated People’s Hospital of Nanchang University(approval No.2020025)on March 26,2020.
基金This work was supported by funding from the National Natural Sciences Foundation of China(NSFC 81430021 and 81370470)the Program for Liaoning Innovative Research Team in University(LT2015009)Liaoning Science and Technology Project(2015225008).
文摘Background:Neuron-microglia communication plays a crucial role in the motor neurons(MNs)death in amyotrophic lateral sclerosis(ALS).Neurons can express chemokine(C-X3-C motif)ligand 1(CX3CL1),which mediates microglial activation via interacting with its sole receptor CX3CR1 in microglia.In the present study,we aimed to investigate the dynamic changes of CX3CL1/CX3CR1 axis during microglial activation and MNs loss in SOD1G93A mouse model of ALS.Methods:qPCR,western blot and immunofluorescent staining were used to examine the mRNA and protein levels and localization of CX3CL1/CX3CR1 in the anterior horn region of spinal cord in both SOD1G93A mice and their agematched wild type(WT)littermates at 40,60,90 and 120 days of age.The M1/M2 microglial activation in the spinal cord tissues of SOD1G93A mice and WT mice were evaluated by immunofluorescent staining of M1/M2 markers and further confirmed by qPCR analysis of M1/M2-related cytokines.Results:The immunofluorescent staining revealed that CX3CL1 was predominately expressed in MNs,while CX3CR1 was highly expressed in microglia in the anterior horn region of spinal cord.Compared with age-matched WT mice,CX3CL1 mRNA level was elevated at 40 days but decreased at 90 and 120 days in the anterior horn region of spinal cords in ALS mice.Consistently,CX3CR1 mRNA level was increased at 90 and 120 days.Western blot assay further confirmed the dynamic changes of CX3CL1/CX3CR1 axis in ALS mice.Additionally,the levels of M1/M2 markers of microglia and their related cytokines in the anterior horn region of spinal cord in ALS mice were increased at 90 and 120 days.Moreover,while M1-related cytokines in ALS mice were persistently increased at 120 days,the upregulated M2-related cytokines started to decline at 120 days,suggesting an altered microglial activation.Conclusions:Our data revealed the dynamic changes of CX3CL1/CX3CR1 axis and an imbalanced M1/M2 microglial activation during ALS pathological progression.These findings may help identify potential molecular targets for ALS therapy.
