Characterisation of functional deficits induced by AAV overexpression of alpha-synuclein in rats

Gubinelli, Francesco; Sarauskyte, Livija; Venuti, Chiara; Kulacz, I; Cazzolla, G; Negrini, Matilde; Anwer, Danish M; Vecchio, Ignazio; Jakobs, F.; Manfredsson, Fredric P.; Davidsson, Marcus; Heuer, Andreas

doi:10.1016/j.crneur.2022.100065

Cited by 7 publications

(4 citation statements)

References 140 publications

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“…Various imaging [ 93 , 94 ] and post-mortem [ 95 – 99 ] studies performed on pre-clinical models of PD as well as on humans samples showed the clear link between inflammation and the disease. In this work, AAV-9 mediated overexpression of h-aSYN produced an increase of IBA1 + cells in the ipsilateral midbrain as compared with the contralateral hemisphere; these results are in accordance with our previously published studies [ 39 , 47 , 100 ]. Interestingly, we observed a slight increase of IBA1 + cells in the ipsilateral midbrain of the AAV-noTG rats compared with the contralateral midbrain receiving no injection.…”

Section: Discussionsupporting

confidence: 94%

A comparison of machine learning approaches for the quantification of microglial cells in the brain of mice, rats and non-human primates

et al. 2023

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Microglial cells are brain-specific macrophages that swiftly react to disruptive events in the brain. Microglial activation leads to specific modifications, including proliferation, morphological changes, migration to the site of insult, and changes in gene expression profiles. A change in inflammatory status has been linked to many neurodegenerative diseases such as Parkinson’s disease and Alzheimer’s disease. For this reason, the investigation and quantification of microglial cells is essential for better understanding their role in disease progression as well as for evaluating the cytocompatibility of novel therapeutic approaches for such conditions. In the following study we implemented a machine learning-based approach for the fast and automatized quantification of microglial cells; this tool was compared with manual quantification (ground truth), and with alternative free-ware such as the threshold-based ImageJ and the machine learning-based Ilastik. We first trained the algorithms on brain tissue obtained from rats and non-human primate immunohistochemically labelled for microglia. Subsequently we validated the accuracy of the trained algorithms in a preclinical rodent model of Parkinson’s disease and demonstrated the robustness of the algorithms on tissue obtained from mice, as well as from images provided by three collaborating laboratories. Our results indicate that machine learning algorithms can detect and quantify microglial cells in all the three mammalian species in a precise manner, equipotent to the one observed following manual counting. Using this tool, we were able to detect and quantify small changes between the hemispheres, suggesting the power and reliability of the algorithm. Such a tool will be very useful for investigation of microglial response in disease development, as well as in the investigation of compatible novel therapeutics targeting the brain. As all network weights and labelled training data are made available, together with our step-by-step user guide, we anticipate that many laboratories will implement machine learning-based quantification of microglial cells in their research.

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Section: Discussionsupporting

confidence: 94%

A comparison of machine learning approaches for the quantification of microglial cells in the brain of mice, rats and non-human primates

et al. 2023

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“…Optical density analysis of the substantia nigra revealed reduced pS129-immunoreactivity in SMM-189-treated animals when normalized against vehicle-treated animals (t(23)=3.353, p=0.0023; Figure 2A,B ). Total and proteinase-K resistant Asyn was also evaluated in the substantia nigra and found that while levels of total human Asyn (Biolegend, clone 4B12) were not different between treatments, SMM-189 decreased PK resistant Asyn compared to vehicle (t(10)=2.303, p=0.044; Figure 2C-F ) when normalized to vehicle nigra measurements. Consistent with histological analyses of pS129 and total Asyn in the nigra, western analysis of the striatum ipsilateral to the overexpression of human Asyn demonstrated reduced pS129 levels in SMM-189-treated rats (t(15)=3.710, p=0.0021), and no differences in total human Asyn levels were found between treatments (p=0.2133; Figure 2G,H ).…”

Section: Resultsmentioning

confidence: 99%

“…In Parkinson's disease (PD), activated microglia have been reported in postmortem brain histopathological analyses and single-cell transcriptomic studies have identified disease-specific increases in midbrain microglia clusters involved in the inflammatory response (3)(4)(5)(6). Findings from animal models demonstrate that overexpression or delivery of fibrillar alpha-synuclein (Asyn) in the brain influences microglial phenotypes and infiltration of peripheral immune cells (5,(7)(8)(9)(10). From a therapeutic perspective, the development of immunomodulatory strategies that dampen overproduction of pro-inflammatory cytokines from chronically activated immune cells and promote a pro-phagocytic phenotype is predicted to protect vulnerable neurons and promote toxic Asyn removal.…”

Section: Introductionmentioning

confidence: 99%

Modulation of cannabinoid receptor 2 alters neuroinflammation and reduces formation of alpha-synuclein aggregates in a rat model of nigral synucleinopathy

Joers,

Murray,

McLaughlin

et al. 2023

Preprint

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There is growing evidence that neuroinflammation accompanies and may promote progression of alpha-synuclein (Asyn)-induced nigral dopaminergic (DA) degeneration. Research into the disequilibrium of microglial phenotypes has become an area of intense focus in neurodegenerative disease as a potential mechanism that contributes to chronic neuroinflammation and neuronal loss in Parkinson’s disease (PD). From a therapeutic perspective, development of immunomodulatory strategies that dampen overproduction of pro-inflammatory cytokines from chronically activated immune cells and induce a pro-phagocytic phenotype is expected to promote Asyn removal and protect vulnerable neurons. Cannabinoid receptor-2 (CB2) is highly expressed on activated microglia and peripheral immune cells, is upregulated in the substantia nigra of PD patients and in mice models of nigral degeneration. Furthermore, modulation of CB2 protects against rotenone-induced nigral degeneration, however CB2 has not been pharmacologically and selectively targeted in an alpha-synuclein focused model of PD. We find that 7 weeks of peripheral SMM-189 treatment reduced phosphorylated (pSer129) alpha-synuclein in the substantia nigra compared to vehicle treatment. Additionally, SMM-189 altered brain immune cell phenotypes with increased CD68 and decreased CD163 protein expression, elevated wound healing immune mediator gene expression and modified leukocyte infiltration kinetics as determined by flow cytometry. Additionally, peripheral immune cells increased wound healing non-classical monocytes and decreased pro-inflammatory classical monocytes. Together, results suggest that targeting CB2 with SMM-189 biased immune cell function toward a phagocytic phenotype and reduced toxic species of alpha-synuclein aggregation. This study highlights that CB2 may be a target for proteinopathies with notable accompanying inflammation.

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“…The release of these neurotransmitters may be disrupted by aggregated forms of α-Syn, causing neurotoxicity [ 46 , 56 ]. The concurrently low levels of the neurotransmitters in the PD flies are traceable to the inhibitory effect of α-Syn on synaptic vesicle re-clustering following endocytosis [ 57 ], leading to motor and non-motor deficits [ 58 ]. Additionally, significant loss of brain dorsomedial dopaminergic neurons has been reported in α-Syn transgenic PD flies [ 14 , 59 ], buttressing the low level of dopamine observed in this study.…”

Section: Discussionmentioning

confidence: 99%

Ribose-cysteine and levodopa abrogate Parkinsonism via the regulation of neurochemical and redox activities in alpha-synuclein transgenic Drosophila melanogaster models

Idowu,

Oremosu,

Dosumu

et al. 2024

Fly

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Parkinson’s disease (PD), the most prevalent type of parkinsonism, is a progressive neurodegenerative condition marked by several non-motor and motor symptoms. PD is thought to have a complex aetiology that includes a combination of age, genetic predisposition, and environmental factors. Increased expression of α-synuclein (α-Syn) protein is central to the evolvement of neuropathology in this devastating disorder, but the potential of ribose-cysteine and levodopa in abating pathophysiologic changes in PD model is unknown. Crosses were set up between flies conditionally expressing a pathological variant of human α-Syn (UAS-α-Syn) and those expressing GAL4 in neurons (elav-GAL4) to generate offspring referred to as PD flies. Flies were randomly assigned to five groups ( n = 40) from the total population of flies, with each group having five replicates. Groups of PD flies were treated with either 500 mg/kg ribose-cysteine diet, 250 mg/kg levodopa diet, or a combination of the two compounds for 21 days, whereas the control group (w 1118 ) and the PD group were exposed to a diet without ribose-cysteine or levodopa. In addition to various biochemical and neurochemical assays, longevity, larval motility, and gravitaxis assays were carried out. Locomotive capability, lifespan, fecundity, antioxidant state, and neurotransmitter systems were all significantly ( p < 0.05) compromised by overexpression of α-Syn. However, flies treated both ribose cysteine and levodopa showed an overall marked improvement in motor functions, lifespan, fecundity, antioxidant status, and neurotransmitter system functions. In conclusion, ribose-cysteine and levodopa, both singly and in combination, potentiated a therapeutic effect on alpha-synuclein transgenic Drosophila melanogaster models of Parkinsonism.

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Characterisation of functional deficits induced by AAV overexpression of alpha-synuclein in rats

Cited by 7 publications

References 140 publications

A comparison of machine learning approaches for the quantification of microglial cells in the brain of mice, rats and non-human primates

A comparison of machine learning approaches for the quantification of microglial cells in the brain of mice, rats and non-human primates

Modulation of cannabinoid receptor 2 alters neuroinflammation and reduces formation of alpha-synuclein aggregates in a rat model of nigral synucleinopathy

Ribose-cysteine and levodopa abrogate Parkinsonism via the regulation of neurochemical and redox activities in alpha-synuclein transgenic Drosophila melanogaster models

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