Animal models of synucleinopathies and how they could impact future drug discovery and delivery efforts

Synucleinopathies: Intrinsic and Extrinsic Factors

α-Synucleinopathies are a group of neurodegenerative disorders characterized by alterations in α-synuclein (α-syn), a protein associated with membrane phospholipids, whose precise function in normal cells is still unknown. These kinds of diseases are caused by multiple factors, but the regulation of the α-syn gene is believed to play a central role in the pathology of these disorders; therefore, the α-syn gene is one of the most studied genes. α-Synucleinopathies are complex disorders that derive from the interaction between genetic and environmental factors. Here, we offer an update on the landscape of the epigenetic regulation of α-syn gene expression that has been linked with α-synucleinopathies. We also delve into the reciprocal influence between epigenetic modifications and other factors related to these disorders, such as posttranslational modifications, microbiota participation, interactions with lipids, neuroinflammation and oxidative stress, to promote α-syn aggregation by acting on the transcription and/or translation of the α-syn gene.

Neuropathology of multiple system atrophy: Kurt Jellinger`s legacy

Multiple System Atrophy (MSA) is a rare, fatal neurodegenerative disorder. Its etiology and exact pathogenesis still remain poorly understood and currently no disease-modifying therapy is available to halt or slow down this detrimental neurodegenerative process. Hallmarks of the disease are α-synuclein rich glial cytoplasmic inclusions (GCIs). Neuropathologically, various degrees of striatonigral degeneration (SND) and olivopontocerebellar atrophy (OPCA) can be observed. Since the original descriptions of this multifaceted disorder, several steps forward have been made to clarify its neuropathological hallmarks and key pathophysiological mechanisms. The Austrian neuropathologist Kurt Jellinger substantially contributed to the understanding of the underlying neuropathology of this disease, to its standardized assessment and to a broad systematical clinic-pathological correlation. On the occasion of his 90th birthday, we reviewed the current state of the art in the field of MSA neuropathology, highlighting Prof. Jellinger’s substantial contribution.

Mesenchymal stem cell secretome protects against alpha-synuclein-induced neurodegeneration in a Caenorhabditis elegans model of Parkinson's disease

BACKGROUND AIMS

The capacity of the secretome from bone marrow-derived mesenchymal stem cells (BMSCs) to prevent dopaminergic neuron degeneration caused by overexpression of alpha-synuclein (α-syn) was explored using two Caenorhabditis elegans models of Parkinson's disease (PD).

METHODS

First, a more predictive model of PD that overexpresses α-syn in dopamine neurons was subjected to chronic treatment with secretome. This strain displays progressive dopaminergic neurodegeneration that is age-dependent. Following chronic treatment with secretome, the number of intact dopaminergic neurons was determined. Following these initial experiments, a C. elegans strain that overexpresses α-syn in body wall muscle cells was used to determine the impact of hBMSC secretome on α-syn inclusions. Lastly, in silico analysis of the components that constitute the secretome was performed.

RESULTS

The human BMSC (hBMSC) secretome induced a neuroprotective effect, leading to reduced dopaminergic neurodegeneration. Moreover, in animals submitted to chronic treatment with secretome, the number of α-syn inclusions was reduced, indicating that the secretome of MSCs was possibly contributing to the degradation of those structures. In silico analysis identified possible suppressors of α-syn proteotoxicity, including growth factors and players in the neuronal protein quality control mechanisms.

CONCLUSIONS

The present findings indicate that hBMSC secretome has the potential to be used as a disease-modifying strategy in future PD regenerative medicine approaches.