Feasibility of combining alpha-synuclein aggregation and 6-OHDA in embryonic midbrain culture for modeling dopamine neuron degeneration.

• Currently no in vitro model recapitulating both dopamine neuron loss and aSyn aggregation. • First study to study the effect of PFF + 6-OHDA in primary midbrain cultures. • 6-OHDA results in dopamine neuron loss in primary midbrain cultures. • aSyn PFFs did not cause dose-dependent loss of TH-positive dopamine neurons in culture. • Optimized PFF + 6-OHDA primary midbrain cultures can be promising model for drug screening. Parkinson's disease (PD) is characterized by the loss of nigrostriatal dopamine (DA) neurons and the presence of alpha-synuclein (αSyn)-positive Lewy body (LB) pathology. In this study, we attempted to recapitulate both these features in a novel in vitro model for PD. To achieve this, we combined the αSyn pre-formed fibril (PFF)-seeded LB-like pathology with 6-hydroxydopamine (6-OHDA)-induced mitochondrial toxicity in mouse embryonic midbrain cultures. To pilot the model for therapeutics testing, we assessed the effects of cerebral dopamine neurotrophic factor (CDNF) on αSyn aggregation and neuron survival. PFF-seeded pathology did not lead to DA neuron loss even with the highest dose of PFFs. The combination of PFFs and 6-OHDA did not trigger additional neurodegeneration or LB–like pathology and instead presented DA neuron loss to a similar extent as with 6-OHDA only. CDNF did not affect the PFF-seeded αSyn pathology or the DA neuron survival in the combination model but showed a trend toward neuroprotection in the 6-OHDA-only cultures. [ABSTRACT FROM AUTHOR]