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
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.