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Updated: Jun 22, 2026
Assessing Cell Cycle Progression of Neural Stem and Progenitor Cells in the Mouse Developing Brain after Genotoxic Stress
Published on: May 7, 2014
Emerging role of LRRK2 in human neural progenitor cell cycle progression, survival and differentiation
Javorina Milosevic1, Sigrid C Schwarz, Vera Ogunlade
1Translational Centre for Regenerative Medicine - Leipzig (TRM-Leipzig), University of Leipzig, Philipp-Rosenthal-Strasse 55, 04103 Leipzig, Germany. jmilosevic@trm.uni-leipzig.de.
Abstract:
Despite a comprehensive mapping of the Parkinson's disease (PD)-related mRNA and protein leucine-rich repeat kinase 2 (LRRK2) in the mammalian brain, its physiological function in healthy individuals remains enigmatic. Based on its structural features and kinase properties, LRRK2 may interact with other proteins involved in signalling pathways. Here, we show a widespread LRRK2 mRNA and/or protein expression in expanded or differentiated human mesencephalic neural progenitor cells (hmNPCs) and in post-mortem substantia nigra PD patients. Using small interfering RNA duplexes targeting LRRK2 in hmNPCs following their differentiation into glia and neurons, we observed a reduced number of dopaminergic neurons due to apoptosis in LRRK2 knockdown samples. LRRK2-deficient hmNPCs exhibited elevated cell cycle- and cell death-related markers. In conclusion, a reduction of LRRK2 expression in hmNPCs severely impaired dopaminergic differentiation and/or survival of dopaminergic neurons most likely via preserving or reactivating the cell cycle.
Insights
Leucine-rich repeat kinase 2 (LRRK2) is crucial for dopaminergic neuron survival. Reduced LRRK2 expression impairs neuron differentiation and survival, potentially by affecting the cell cycle.
Area of Science:
- Neuroscience
- Cell Biology
- Genetics
Background:
- The physiological role of Leucine-rich repeat kinase 2 (LRRK2) in healthy individuals is not well understood, despite its known association with Parkinson's disease (PD).
- LRRK2's structural and kinase properties suggest potential involvement in cellular signaling pathways.
Purpose of the Study:
- To investigate the function of LRRK2 in the differentiation and survival of dopaminergic neurons.
- To explore the impact of LRRK2 deficiency on human mesencephalic neural progenitor cells (hmNPCs).
Main Methods:
- LRRK2 expression was analyzed in hmNPCs and post-mortem substantia nigra from PD patients.
- Small interfering RNA (siRNA) was used to knock down LRRK2 expression in differentiating hmNPCs.
- Cellular markers related to cell cycle and apoptosis were assessed in LRRK2-deficient cells.
Main Results:
- LRRK2 mRNA and protein were widely expressed in hmNPCs and PD patient tissues.
- Knockdown of LRRK2 in hmNPCs led to a significant reduction in dopaminergic neurons due to apoptosis.
- LRRK2-deficient hmNPCs showed increased markers of cell cycle progression and cell death.
Conclusions:
- Reduced LRRK2 expression severely impairs dopaminergic differentiation and survival of dopaminergic neurons.
- The mechanism likely involves the preservation or reactivation of the cell cycle in LRRK2-deficient cells.
- These findings highlight LRRK2's critical role in maintaining dopaminergic neuron homeostasis.
