Dataset Information

Untargeted Mass Spectrometry Metabolomic Profiles of iPSC-derived Dopaminergic Neurons from Clinically Discordant Brothers with Identical PRKN Deletions

ABSTRACT: We have previously reported on two brothers, PM and SM, who carry identical compound heterozygous PRKN mutations but present with very different clinical Parkinson’s disease (PD) phenotypes, with PM, but not SM having been diagnosed with early onset disease. The occurrence of juvenile cases demonstrates that PD is not necessarily an age-associated disease, indeed evidence is accumulating that there is a developmental component to PD pathogenesis. We hypothesize that additional genetic modifiers, potentially including genetic loci relevant to mesencephalic dopamine neuron development may play a role. We differentiated human-induced pluripotent stem cells (hiPSCs) derived from SM and PM into mitotically active mesencephalic neural precursor cells and early postmitotic dopaminergic neurons and performed whole exome sequencing, transcriptomic- and metabolomic analyses. No significant differences in canonical markers of differentiation were observed between SM and PM. Yet our transcriptomic analysis revealed a significant down regulation of three neurodevelopmentally relevant cell adhesion molecules, CNTN6, CNTN4 and CHL1 in PM- compared to SM cultures on days 11 and 25 of differentiation. In addition, several HLA genes, known to play a role in neurodevelopment, independent of their well-established function in immunity, were differentially regulated in PM and SM developing dopamine neurons. EN2, a transcription factor crucial for mesencephalic dopamine neuron development, was also differentially regulated. We further observed differences in cellular processes relevant to dopamine homeostasis. Lastly, our whole exome sequencing, transcriptomics and metabolomics data of SM and PM neurons revealed differences in GSH homeostasis, the dysregulation of which has been associated with PD.

ORGANISM(S): Human Homo Sapiens

TISSUE(S): Skin

DISEASE(S): Parkinsons Disease

SUBMITTER: SIMONA CODREANU

PROVIDER: ST001957 | MetabolomicsWorkbench | Wed Oct 13 00:00:00 BST 2021

REPOSITORIES: MetabolomicsWorkbench

ACCESS DATA

Dataset's files

Source:

			Action	DRS
	mwtab	Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:We have previously reported on two brothers, PM and SM, that carry identical compound heterozygous PRKN mutations but show significantly different clinical Parkinson disease (PD) phenotypes. The occurrence of juvenile cases demonstrates that PD is not necessarily an age-associated disease; indeed, evidence is accumulating that there is a developmental component to PD pathogenesis. The divergence in the clinical presentations between PM and SM lead us to hypothesize that an additional genetic modifier(s) may influence the risk conferred by PRKN. To test our hypothesis, we differentiated human induced pluripotent stem cells (iPSCs) from SM and PM into mitotically active mesencephalic neural precursor cells (floor plate cells) and early postmitotic dopaminergic neurons, and performed whole exome sequencing, and transcriptomic and metabolomics analysis. Our transcriptomic analysis revealed a significant down regulation of three known neurodevelopmentally relevant cell adhesion molecules in PM compared to SM cultures on days 11 and 25 of differentiation, CNTN4, CNTN6, and CHL1. In addition, several HLA genes, known to play a role in neurodevelopment, independent of their well-established function in immunity, were differentially regulated in developing dopamine neurons. EN2, a transcription factor crucial for mesencephalic dopamine neuron development, was also differentially regulated. We further report on a single nucleotide polymorphism in DBH, a gene encoding an enzyme involved in dopamine metabolism, as well as differential expression. Our metabolomics data reveal differential biosynthesis of tyrosine, the precursor for dopamine synthesis. Lastly, our whole exome sequencing revealed the homozygous deletion in SM of two glutathione S-transferases, GSTM1 and GSTT1, which encode enzymes involved in glutathione (GSH) metabolism. Moreover, our RNA sequencing analysis shows a lack of expression of these two enzymes in SM cells and our metabolomics analysis indicates differences in GSH homeostasis between SM and PM neurons. This finding builds on previous evidence of glutathione dysregulation being implicated in PD pathogenesis. Our data support our hypothesis that additional genetic differences at least partially underlie the differential clinical PD presentation between PM and SM.

Project description:The gain-of-function mutation of c.G6055A (p.G2019S) in Leucine-rich repeat kinase 2 (LRRK2) gene is the most prevalent genetic cause of Parkinson’s disease (PD). Although clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-based genome editing has been used to generate isogenic control lines, there are risks of creating indels and genomic instability together with a lower efficiency in non-dividing cells. The recent advance of adenine base editors (ABEs) could convert targeted A•T base pairs to G•C base pairs without double-strand DNA breaks or donor DNA templates and function in post-mitotic cells. Here, we demonstrate a complete correction of an induced pluripotent stem cell (iPSC) line derived from a PD patient having LRRK2 p.G2019S mutation using variable genome editing methods, including CRISPR/Cas9-based homology-directed repair (HDR) and ABEs. The corrected isogenic iPSCs derived dopaminergic neurons showed a down-regulated LRRK2 kinase activity, decreased phospho-a-synuclein accumulations, reduced apoptosis and restored neurite shrinkage phenotypes. The mutation correction efficacy, off-target and indels rates between CRISPR/Cas9-HDR and ABE were compared. Among the 47 clones generated by HDR, 3 clones (6.4%) were on-targeted corrected, while ABE showed a much higher correction rate (13 of 53 clones, 24.5%). Whole genome sequencing analysis revealed that there are 27 clones of HDR (57.4%) having deletions but none in clones of ABE, albeit ABE created 14 clones (26.4%) having off-target missense mutations. RNA sequencing and proteomic analysis of the mutant line identified 2220 differentially expressed genes compared with its isogenic control. Enrichment analysis demonstrated an over-representation of PD relevant pathways, including calcium ion dependent exocytosis, synaptic transports well as potential novel targets relevant to PD pathophysiology. These results envision that ABE could directly correct the pathogenic PD mutation in iPSCs for exploring the earliest events in PD pathophysiology and providing dopaminergic neurons for future cell therapies.

Dataset Information

Untargeted Mass Spectrometry Metabolomic Profiles of iPSC-derived Dopaminergic Neurons from Clinically Discordant Brothers with Identical PRKN Deletions

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets