MicroRNA alterations in iPSC-derived dopaminergic neurons from Parkinson disease patients

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• MicroRNA (miRNA) dysregulation in Parkinson disease (PD) is known, but its specific role in disease progression within affected neurons is unclear.
• Investigating miRNA expression in dopaminergic neurons (DAn) is crucial for understanding PD pathogenesis.

Purpose of the Study:

• To explore genome-wide miRNA expression in DAn derived from PD patients.
• To identify specific miRNAs associated with sporadic PD (sPD) and leucine-rich repeat kinase 2-associated PD (L2PD).
• To investigate the relationship between miRNA and mRNA expression, and epigenetic changes in PD DAn.

Main Methods:

• Generated DAn from induced pluripotent stem cells of PD patients and healthy controls.
• Quantified expression levels of 377 miRNAs using genome-wide analysis.
• Performed integrative analysis of miRNA/mRNA expression and DNA methylation data.

Main Results:

• Identified differential expression of 10 miRNAs in PD DAn, with 5 upregulated and 5 downregulated.
• Observed similar miRNA expression changes in both sPD and L2PD.
• Found correlations between miRNA and mRNA expression, and linked upregulation of miR-9-5p and miR-135b-5p to downregulation of transcription factors (FOXA1, NR3C1) involved in DNA hypermethylation.

Conclusions:

• miRNA expression profiles are altered in DAn from both monogenic L2PD and sPD patients.
• These miRNA alterations co-occur with epigenetic changes in PD DAn.
• The findings provide insights into molecular mechanisms underlying PD progression.