Related Experiment Video
Updated: Nov 12, 2025
Studying Cell Cycle-regulated Gene Expression by Two Complementary Cell Synchronization Protocols
Published on: June 6, 2017
Comprehensive miRNome-Wide Profiling in a Neuronal Cell Model of Synucleinopathy Implies Involvement of Cell Cycle
Elisabeth Findeiss1,2, Sigrid C Schwarz1, Valentin Evsyukov1,2,3
1Department of Translational Neurodegeneration, German Center for Neurodegenerative Diseases, Munich, Germany.
Abstract:
Growing evidence suggests that epigenetic mechanisms like microRNA-mediated transcriptional regulation contribute to the pathogenesis of parkinsonism. In order to study the influence of microRNAs (miRNAs), we analyzed the miRNome 2 days prior to major cell death in α-synuclein-overexpressing Lund human mesencephalic neurons, a well-established cell model of Parkinson's disease (PD), by next-generation sequencing. The expression levels of 23 miRNAs were significantly altered in α-synuclein-overexpressing cells, 11 were down- and 12 upregulated (P < 0.01; non-adjusted). The in silico analysis of known target genes of these miRNAs was complemented by the inclusion of a transcriptome dataset (BeadChip) of the same cellular system, revealing the G0/G1 cell cycle transition to be markedly enriched. Out of 124 KEGG-annotated cell cycle genes, 15 were present in the miRNA target gene dataset and six G0/G1 cell cycle genes were found to be significantly altered upon α-synuclein overexpression, with five genes up- (CCND1, CCND2, and CDK4 at P < 0.01; E2F3, MYC at P < 0.05) and one gene downregulated (CDKN1C at P < 0.001). Additionally, several of these altered genes are targeted by miRNAs hsa-miR-34a-5p and hsa-miR-34c-5p, which also modulate α-synuclein expression levels. Functional intervention by siRNA-mediated knockdown of the cell cycle gene cyclin D1 (CCND1) confirmed that silencing of cell cycle initiation is able to substantially reduce α-synuclein-mediated cytotoxicity. The present findings suggest that α-synuclein accumulation induces microRNA-mediated aberrant cell cycle activation in post-mitotic dopaminergic neurons. Thus, the mitotic cell cycle pathway at the level of miRNAs might offer interesting novel therapeutic targets for PD.
Insights
Parkinson's disease involves microRNAs (miRNAs) affecting cell cycle genes. Targeting these cell cycle pathways offers potential new therapies for Parkinson's disease.
Area of Science:
- Neuroscience
- Epigenetics
- Molecular Biology
Background:
- Parkinson's disease (PD) pathogenesis is increasingly linked to epigenetic mechanisms, particularly microRNA (miRNA)-mediated transcriptional regulation.
- α-synuclein accumulation is a key pathological hallmark in Parkinson's disease.
- Understanding miRNA dysregulation in PD is crucial for identifying novel therapeutic targets.
Purpose of the Study:
- To investigate the role of miRNAs in the pathogenesis of Parkinson's disease using an α-synuclein overexpression model.
- To identify specific miRNAs and their target genes involved in cellular processes during PD progression.
- To explore the therapeutic potential of targeting miRNA-mediated cell cycle dysregulation in PD.
Main Methods:
- Analyzed the miRNome in α-synuclein-overexpressing Lund human mesencephalic neurons using next-generation sequencing.
- Integrated miRNA expression data with transcriptome (BeadChip) and KEGG pathway analysis to identify dysregulated genes and pathways.
- Utilized siRNA-mediated knockdown of cyclin D1 (CCND1) to assess its effect on α-synuclein-mediated cytotoxicity.
Main Results:
- Significant alterations in the expression of 23 miRNAs were observed in α-synuclein-overexpressing neurons.
- The G0/G1 cell cycle transition was markedly enriched, with six key cell cycle genes showing altered expression.
- Knockdown of cyclin D1 (CCND1) significantly reduced α-synuclein-induced cytotoxicity, implicating cell cycle activation in PD pathogenesis.
Conclusions:
- α-synuclein accumulation triggers microRNA-mediated aberrant cell cycle activation in post-mitotic dopaminergic neurons.
- Specific miRNAs, including hsa-miR-34a-5p and hsa-miR-34c-5p, are involved in modulating α-synuclein levels and cell cycle genes.
- The mitotic cell cycle pathway regulated by miRNAs represents a promising novel therapeutic target for Parkinson's disease.
