The selective vulnerability of nigrostriatal dopaminergic neurons is a hallmark of Parkinson’s disease and underlies its progressive motor decline.These neurons are uniquely susceptible to degeneration due to their e...The selective vulnerability of nigrostriatal dopaminergic neurons is a hallmark of Parkinson’s disease and underlies its progressive motor decline.These neurons are uniquely susceptible to degeneration due to their extensive axonal arborization,high energy demands,sustained pacemaking activity,and cytosolic dopamine metabolism,which collectively promote oxidative stress and mitochondrial dysfunction.Advances in single-nucleus RNA sequencing and spatial transcriptomics have revealed transcriptionally distinct dopaminergic subtypes within the human substantia nigra pars compacta,such as AGTR1+/SOX6+and RIT2+populations,which exhibit subtype-specific transcriptional stress signatures and are preferentially lost in Parkinson’s disease.These findings underscore the role of intrinsic vulnerability,influenced by genetic risk loci,mitochondrial stress,and protein misfolding pathways,includingα-synuclein aggregation.Furthermore,neuroinflammation,iron accumulation,and vascular dysfunction act synergistically to amplify neuronal loss.This review integrates molecular,cellular,and systems-level mechanisms contributing to dopaminergic degeneration and evaluates emerging neuroprotective strategies.These include anti-oxidative,anti-inflammatory,mitochondrial therapies,novel biomarkers,gene editing,and cell replacement techniques.Understanding the selective vulnerability of nigrostriatal subtypes offers a promising path toward precision-targeted,disease-modifying treatments for Parkinson’s disease.展开更多
Parkinsonism by unilateral,intranigralβ-sitosterolβ-D-glucoside administration in rats is distinguished in that theα-synuclein insult begins unilaterally but spreads bilaterally and increases in severity over time,...Parkinsonism by unilateral,intranigralβ-sitosterolβ-D-glucoside administration in rats is distinguished in that theα-synuclein insult begins unilaterally but spreads bilaterally and increases in severity over time,thus replicating several clinical features of Parkinson’s disease,a typicalα-synucleinopathy.As Nurr1 repressesα-synuclein,we evaluated whether unilateral transfected of rNurr1-V5 transgene via neurotensin-polyplex to the substantia nigra on day 30 after unilateralβ-sitosterolβ-D-glucoside lesion could affect bilateral neuropathology and sensorimotor deficits on day 30 post-transfection.This study found that rNurr1-V5 expression but not that of the green fluorescent protein(the negative control)reducedβ-sitosterolβ-D-glucoside-induced neuropathology.Accordingly,a bilateral increase in tyrosine hydroxylase-positive cells and arborization occurred in the substantia nigra and increased tyrosine hydroxylase-positive ramifications in the striatum.In addition,tyrosine hydroxylase-positive cells displayed less senescence markerβ-galactosidase and more neuron-cytoskeleton markerβIII-tubulin and brain-derived neurotrophic factor.A significant decrease in activated microglia(positive to ionized calcium-binding adaptor molecule 1)and neurotoxic astrocytes(positive to glial fibrillary acidic protein and complement component 3)and increased neurotrophic astrocytes(positive to glial fibrillary acidic protein and S100 calcium-binding protein A10)also occurred in the substantia nigra.These effects followed the bilateral reduction inα-synuclein aggregates in the nigrostriatal system,improving sensorimotor behavior.Our results show that unilateral rNurr1-V5 transgene expression in nigral dopaminergic neurons mitigates bilateral neurodegeneration(senescence and loss of neuron-cytoskeleton and tyrosine hydroxylase-positive cells),neuroinflammation(activated microglia,neurotoxic astrocytes),α-synuclein aggregation,and sensorimotor deficits.Increased neurotrophic astrocytes and brain-derived neurotrophic factor can mediate the rNurr1-V5 effect,supporting its potential clinical use in the treatment of Parkinson’s disease.展开更多
Overexpression of neurotrophic factors in nigral dopamine neurons is a promising approach to reverse neurodegeneration of the nigrostriatal dopamine system,a hallmark in Parkinson's disease.The human cerebral dopa...Overexpression of neurotrophic factors in nigral dopamine neurons is a promising approach to reverse neurodegeneration of the nigrostriatal dopamine system,a hallmark in Parkinson's disease.The human cerebral dopamine neurotrophic factor(h CDNF)has recently emerged as a strong candidate for Parkinson's disease therapy.This study shows that h CDNF expression in dopamine neurons using the neurotensinpolyplex nanoparticle system reverses 6-hydroxydopamine-induced morphological,biochemical,and behavioral alterations.Three independent electron microscopy techniques showed that the neurotensin-polyplex nanoparticles containing the h CDNF gene,ranging in size from 20 to 150 nm,enabled the expression of a secretable h CDNF in vitro.Their injection in the substantia nigra compacta on day 21 after the 6-hydroxydopamine lesion resulted in detectable h CDNF in dopamine neurons,whose levels remained constant throughout the study in the substantia nigra compacta and striatum.Compared with the lesioned group,tyrosine hydroxylase-positive(TH^(+))nigral cell population and TH+fiber density rose in the substantia nigra compacta and striatum after h CDNF transfection.An increase inβIII-tubulin and growth-associated protein 43 phospho-S41(GAP43 p)followed TH^(+)cell recovery,as well as dopamine and its catabolite levels.Partial reversal(80%)of drugactivated circling behavior and full recovery of spontaneous motor and non-motor behavior were achieved.Brain-derived neurotrophic factor recovery in dopamine neurons that also occurred suggests its participation in the neurotrophic effects.These findings support the potential of nanoparticle-mediated h CDNF gene delivery to develop a disease-modifying treatment against Parkinson's disease.The Institutional Animal Care and Use Committee of Centro de Investigación y de Estudios Avanzados approved our experimental procedures for animal use(authorization No.162-15)on June 9,2019.展开更多
文摘The selective vulnerability of nigrostriatal dopaminergic neurons is a hallmark of Parkinson’s disease and underlies its progressive motor decline.These neurons are uniquely susceptible to degeneration due to their extensive axonal arborization,high energy demands,sustained pacemaking activity,and cytosolic dopamine metabolism,which collectively promote oxidative stress and mitochondrial dysfunction.Advances in single-nucleus RNA sequencing and spatial transcriptomics have revealed transcriptionally distinct dopaminergic subtypes within the human substantia nigra pars compacta,such as AGTR1+/SOX6+and RIT2+populations,which exhibit subtype-specific transcriptional stress signatures and are preferentially lost in Parkinson’s disease.These findings underscore the role of intrinsic vulnerability,influenced by genetic risk loci,mitochondrial stress,and protein misfolding pathways,includingα-synuclein aggregation.Furthermore,neuroinflammation,iron accumulation,and vascular dysfunction act synergistically to amplify neuronal loss.This review integrates molecular,cellular,and systems-level mechanisms contributing to dopaminergic degeneration and evaluates emerging neuroprotective strategies.These include anti-oxidative,anti-inflammatory,mitochondrial therapies,novel biomarkers,gene editing,and cell replacement techniques.Understanding the selective vulnerability of nigrostriatal subtypes offers a promising path toward precision-targeted,disease-modifying treatments for Parkinson’s disease.
文摘Parkinsonism by unilateral,intranigralβ-sitosterolβ-D-glucoside administration in rats is distinguished in that theα-synuclein insult begins unilaterally but spreads bilaterally and increases in severity over time,thus replicating several clinical features of Parkinson’s disease,a typicalα-synucleinopathy.As Nurr1 repressesα-synuclein,we evaluated whether unilateral transfected of rNurr1-V5 transgene via neurotensin-polyplex to the substantia nigra on day 30 after unilateralβ-sitosterolβ-D-glucoside lesion could affect bilateral neuropathology and sensorimotor deficits on day 30 post-transfection.This study found that rNurr1-V5 expression but not that of the green fluorescent protein(the negative control)reducedβ-sitosterolβ-D-glucoside-induced neuropathology.Accordingly,a bilateral increase in tyrosine hydroxylase-positive cells and arborization occurred in the substantia nigra and increased tyrosine hydroxylase-positive ramifications in the striatum.In addition,tyrosine hydroxylase-positive cells displayed less senescence markerβ-galactosidase and more neuron-cytoskeleton markerβIII-tubulin and brain-derived neurotrophic factor.A significant decrease in activated microglia(positive to ionized calcium-binding adaptor molecule 1)and neurotoxic astrocytes(positive to glial fibrillary acidic protein and complement component 3)and increased neurotrophic astrocytes(positive to glial fibrillary acidic protein and S100 calcium-binding protein A10)also occurred in the substantia nigra.These effects followed the bilateral reduction inα-synuclein aggregates in the nigrostriatal system,improving sensorimotor behavior.Our results show that unilateral rNurr1-V5 transgene expression in nigral dopaminergic neurons mitigates bilateral neurodegeneration(senescence and loss of neuron-cytoskeleton and tyrosine hydroxylase-positive cells),neuroinflammation(activated microglia,neurotoxic astrocytes),α-synuclein aggregation,and sensorimotor deficits.Increased neurotrophic astrocytes and brain-derived neurotrophic factor can mediate the rNurr1-V5 effect,supporting its potential clinical use in the treatment of Parkinson’s disease.
基金supported by the Consejo Nacional de Ciencia Tecnología(Conacyt)de México(Grant#254686,to DMF)。
文摘Overexpression of neurotrophic factors in nigral dopamine neurons is a promising approach to reverse neurodegeneration of the nigrostriatal dopamine system,a hallmark in Parkinson's disease.The human cerebral dopamine neurotrophic factor(h CDNF)has recently emerged as a strong candidate for Parkinson's disease therapy.This study shows that h CDNF expression in dopamine neurons using the neurotensinpolyplex nanoparticle system reverses 6-hydroxydopamine-induced morphological,biochemical,and behavioral alterations.Three independent electron microscopy techniques showed that the neurotensin-polyplex nanoparticles containing the h CDNF gene,ranging in size from 20 to 150 nm,enabled the expression of a secretable h CDNF in vitro.Their injection in the substantia nigra compacta on day 21 after the 6-hydroxydopamine lesion resulted in detectable h CDNF in dopamine neurons,whose levels remained constant throughout the study in the substantia nigra compacta and striatum.Compared with the lesioned group,tyrosine hydroxylase-positive(TH^(+))nigral cell population and TH+fiber density rose in the substantia nigra compacta and striatum after h CDNF transfection.An increase inβIII-tubulin and growth-associated protein 43 phospho-S41(GAP43 p)followed TH^(+)cell recovery,as well as dopamine and its catabolite levels.Partial reversal(80%)of drugactivated circling behavior and full recovery of spontaneous motor and non-motor behavior were achieved.Brain-derived neurotrophic factor recovery in dopamine neurons that also occurred suggests its participation in the neurotrophic effects.These findings support the potential of nanoparticle-mediated h CDNF gene delivery to develop a disease-modifying treatment against Parkinson's disease.The Institutional Animal Care and Use Committee of Centro de Investigación y de Estudios Avanzados approved our experimental procedures for animal use(authorization No.162-15)on June 9,2019.
