Regulation of MicroRNA-4697-3p by Parkinson's disease-associated SNP rs329648 and its impact on SNCA112 mRNA

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by a multifaceted genetic foundation. Genome-Wide Association Studies (GWAS) have played a crucial role in pinpointing genetic variants linked to PD susceptibility. Current study aims to delve into the mechanistic aspects through which the PD-associated Single Nucleotide Polymorphism (SNP) rs329648, identified in prior GWAS, influences the pathogenesis of PD.

Employing the CRISPR/Cas9-mediated genome editing mechanism, we demonstrated the association of the disease-associated allele of rs329648 with increased expression of miR-4697-3p in differentiated SH-SY5Y cells. We revealed that miR-4697-3p contributes to the formation of high molecular weight complexes of α-Synuclein (α-Syn), indicative of α-Syn aggregate formation, as evidenced by Western blot analysis. Furthermore, our study unveiled that miR-4697-3p elevates SNCA112 mRNA levels. The resultant protein product, α-Syn 112, a variant of α-Syn with 112 amino acids, is recognized for augmenting α-Syn aggregation. Notably, this regulatory effect minimally impacts the levels of full-length SNCA140 mRNA, as evidenced by qRT-PCR. Additionally, we observed a correlation between the disease-associated allele and miR-4697-3p with increased cell death, substantiated by assessments including cell viability assays, alterations in cell morphology, and TUNEL assays.

Our research reveals that the disease-associated allele of rs329648 is linked to higher levels of miR-4697-3p. This increase in miR-4697-3p leads to elevated SNCA112 mRNA levels, consequently promoting the formation of α-Syn aggregates. Furthermore, miR-4697-3p appears to play a role in increased cell death, potentially contributing to the pathogenesis of PD.