Induced Pluripotent Stem Cell-Derived Dopaminergic Neurons from Familial Parkinson’s Disease Patients Display α-Synuclein Pathology and Abnormal Mitochondrial Morphology

Abstract

Accumulation of α-synuclein (α-syn) into Lewy bodies (LBs) and mitochondrial abnormalities are the two cardinal pathobiological features of Parkinson’s disease (PD), which are associated with the loss of dopaminergic neurons. Although α-syn accumulates in many different cellular and mouse models, these models generally lack LB features. Here, we generated midbrain dopaminergic (mDA) neuronal cultures from induced pluripotent stem cells (iPSCs) derived from familial PD (fPD) patients and healthy controls. We show that mDA neuronal cultures from fPD patients with A53T mutation and α-syn gene (SNCA) triplication display pathological α-syn deposits, which spatially and morphologically resemble LBs. Importantly, we did not find any apparent accumulation of pathological α-syn in mDA neuronal culture derived from a healthy donor. Furthermore, we show that there are morphological abnormalities in the mitochondrial network in mDA neuronal cultures from fPD patients. Consequently, these cells were more susceptible to mitochondrial damage compared with healthy donor-derived mDA neuronal cultures. Our results indicate that the iPSC-derived mDA neuronal culture platform can be used to investigate the spatiotemporal appearance of LBs, as well as their composition, architecture, and relationship with mitochondrial abnormalities.

Mitochondrial fitness influences neuronal excitability of dopaminergic neurons from patients with idiopathic form of Parkinson’s disease

“…We did not observe major differences in differentiation potential between IPD and HV derived DA neurons, which is contrary to previously published studies that observed changes in biology of DA neurons including proliferation and differentiation 17 . However, these studies were carried on predominantly using iPS cells derived from familial form of PD 18 or YOPD 13 , whereas we used IPD derived iPS cells. Accordingly, we did not observe statistically significant differences in production of DA and its metabolite derivatives, whereas previous studies suggested different DA production levels in neurons derived from iPS cells 19 .…”

Identification of DOT1L inhibitor in a screen for factors that promote dopaminergic neuron survival

“…The efficiency of DA neuron induction in vitro with these modified protocols has been shown to be similar across different cell lines of different genetic backgrounds including those carrying mutations in genes associated with PD such as the SNCA triplication (α-synuclein triplication) cell liner. When iPSCderived DA neurons from PD-affected individuals are probed further, independent of genetic cause, they have been shown to display cardinal features of neurodegeneration including formation of α-synuclein aggregates, dysregulation of neurotransmission, and increased susceptibility of DA neurons, relative to non-DA neurons, to diverse neurotoxins as indicated by cell death and overexpression of markers of oxidative stress, culminating in cell death (Byers et al, 2011;Nguyen et al, 2011;Baena-Montes et al, 2021;Diao et al, 2021;Fukusumi et al, 2021;Lin et al, 2021;Drouin-Ouellet et al, 2022). Whether the PD features observed correspond to changes in vivo in the midbrain was also addressed, at least in part, in studies that compared transcriptional profiles of human induced and primary midbrain dopaminergic neurons (Xia et al, 2016).…”