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1.
Biomolecules ; 14(7)2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-39062470

RESUMEN

Aggregation of the protein α-Synuclein (αSyn) is a hallmark of Parkinson's disease (PD), dementia with Lewy bodies (DLB) and multiple systems atrophy, and alleviating the extent of αSyn pathology is an attractive strategy against neurodegeneration. The engineered binding protein ß-wrapin AS69 binds monomeric αSyn. AS69 reduces primary and secondary nucleation as well as fibril elongation in vitro. It also mitigates aSyn pathology in a mouse model based on intrastriatal injection of aSyn pre-formed fibrils (PFFs). Since the PFF-based model does not represent all aspects of PD, we tested here whether AS69 can reduce neurodegeneration resulting from αSyn overexpression. Human A53T-αSyn was overexpressed in the mouse Substantia nigra (SN) by using recombinant adeno-associated viral vector (rAAV). AS69 was also expressed by rAAV transduction. Behavioral tests and immunofluorescence staining were used as outcomes. Transduction with rAAV-αSyn resulted in αSyn pathology as reported by phospho-αSyn staining and caused degeneration of dopaminergic neurons in the SN. The co-expression of rAAV-AS69 did not reduce αSyn pathology or the degeneration of dopaminergic neurons. We conclude that αSyn monomer binding by rAAV-AS69 was insufficient to protect from aSyn pathology resulting from αSyn overexpression.


Asunto(s)
Modelos Animales de Enfermedad , Sustancia Negra , alfa-Sinucleína , Animales , alfa-Sinucleína/metabolismo , alfa-Sinucleína/genética , Ratones , Humanos , Sustancia Negra/metabolismo , Sustancia Negra/patología , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/patología , Dependovirus/genética , Neuronas Dopaminérgicas/metabolismo , Neuronas Dopaminérgicas/efectos de los fármacos , Masculino , Ratones Endogámicos C57BL
2.
Exp Neurol ; 347: 113900, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34695425

RESUMEN

During the pathogenesis of Parkinson's disease (PD), aggregation of alpha-synuclein (αSyn) induces a vicious cycle of cellular impairments that lead to neurodegeneration. Consequently, removing toxic αSyn aggregates constitutes a plausible strategy against PD. In this work, we tested whether stimulating the autolysosomal degradation of αSyn aggregates through the Ras-related in brain 7 (Rab7) pathway can reverse αSyn-induced cellular impairment and prevent neurodegeneration in vivo. The disease-related A53T mutant of αSyn was expressed in primary neurons and in dopaminergic neurons of the rat brain simultaneously with wild type (WT) Rab7 or the T22N mutant as negative control. The cellular integrity was quantified by morphological and biochemical analyses. In primary neurons, WT Rab7 rescued the αSyn-induced loss of neurons and neurites. Furthermore, Rab7 decreased the amount of reactive oxygen species and the amount of Triton X-100 insoluble αSyn. In rat brain, WT Rab7 reduced αSyn-induced loss of dopaminergic axon terminals in the striatum and the loss of dopaminergic dendrites in the substantia nigra pars reticulata. Further, WT Rab7 lowered αSyn pathology as quantified by phosphorylated αSyn staining. Finally, WT Rab7 attenuated αSyn-induced DNA damage in primary neurons and rat brain. In brief, Rab7 reduced αSyn-induced pathology, ameliorated αSyn-induced neuronal degeneration, oxidative stress and DNA damage. These findings indicate that Rab7 is able to disrupt the vicious cycle of cellular impairment, αSyn pathology and neurodegeneration present in PD. Stimulation of Rab7 and the autolysosomal degradation pathway could therefore constitute a beneficial strategy for PD.


Asunto(s)
Neuronas Dopaminérgicas/metabolismo , alfa-Sinucleína/biosíntesis , alfa-Sinucleína/toxicidad , Proteínas de Unión a GTP rab7/biosíntesis , Proteínas de Unión a GTP rab7/farmacología , Animales , Células Cultivadas , Daño del ADN/efectos de los fármacos , Daño del ADN/fisiología , Neuronas Dopaminérgicas/efectos de los fármacos , Neuronas Dopaminérgicas/patología , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo
3.
Front Neurosci ; 15: 696440, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34326719

RESUMEN

Reducing α-synuclein pathology constitutes a plausible strategy against Parkinson's disease. As we recently demonstrated, the ß-wrapin protein AS69 binds an N-terminal region in monomeric α-synuclein, interferes with fibril nucleation, and reduces α-synuclein aggregation in vitro and in a fruit fly model of α-synuclein toxicity. The aim of this study was to investigate whether AS69 also reduces α-synuclein pathology in mammalian neurons. To induce α-synuclein pathology, primary mouse neurons were exposed to pre-formed fibrils (PFF) of human α-synuclein. PFF were also injected into the striatum of A30P-α-synuclein transgenic mice. The extent of α-synuclein pathology was determined by phospho-α-synuclein staining and by Triton X-100 solubility. The degeneration of neuronal somata, dendrites, and axon terminals was determined by immunohistochemistry. AS69 and PFF were taken up by primary neurons. AS69 did not alter PFF uptake, but AS69 did reduce PFF-induced α-synuclein pathology. PFF injection into mouse striatum led to α-synuclein pathology and dystrophic neurites. Co-injection of AS69 abrogated PFF-induced pathology. AS69 also reduced the PFF-induced degeneration of dopaminergic axon terminals in the striatum and the degeneration of dopaminergic dendrites in the substantia nigra pars reticulata. AS69 reduced the activation of astroglia but not microglia in response to PFF injection. Collectively, AS69 reduced PFF-induced α-synuclein pathology and the associated neurodegeneration in primary neurons and in mouse brain. Our data therefore suggest that small proteins binding the N-terminus of α-synuclein monomers are promising strategies to modify disease progression in Parkinson's disease.

4.
Cell Rep ; 29(9): 2862-2874.e9, 2019 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-31775051

RESUMEN

Intracellular accumulation of α-synuclein (α-syn) and formation of Lewy bodies are neuropathological characteristics of Parkinson's disease (PD) and related α-synucleinopathies. Oligomerization and spreading of α-syn from neuron to neuron have been suggested as key events contributing to the progression of PD. To directly visualize and characterize α-syn oligomerization and spreading in vivo, we generated two independent conditional transgenic mouse models based on α-syn protein complementation assays using neuron-specifically expressed split Gaussia luciferase or split Venus yellow fluorescent protein (YFP). These transgenic mice allow direct assessment of the quantity and subcellular distribution of α-syn oligomers in vivo. Using these mouse models, we demonstrate an age-dependent accumulation of a specific subtype of α-syn oligomers. We provide in vivo evidence that, although α-syn is found throughout neurons, α-syn oligomerization takes place at the presynapse. Furthermore, our mouse models provide strong evidence for a transsynaptic cell-to-cell transfer of de novo generated α-syn oligomers in vivo.


Asunto(s)
Neuronas/metabolismo , Enfermedad de Parkinson/genética , alfa-Sinucleína/metabolismo , Animales , Modelos Animales de Enfermedad , Humanos , Ratones
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