Related Experiment Video
Updated: Apr 28, 2026
Primary Culture of Mouse Dopaminergic Neurons
Published on: September 8, 2014
DYRK1A promotes dopaminergic neuron survival in the developing brain and in a mouse model of Parkinson's disease
M J Barallobre1, C Perier2, J Bové2
1Department of Developmental Biology, Instituto de Biología Molecular de Barcelona, CSIC, and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Spain.
Abstract:
In the brain, programmed cell death (PCD) serves to adjust the numbers of the different types of neurons during development, and its pathological reactivation in the adult leads to neurodegeneration. Dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A) is a pleiotropic kinase involved in neural proliferation and cell death, and its role during brain growth is evolutionarily conserved. Human DYRK1A lies in the Down syndrome critical region on chromosome 21, and heterozygous mutations in the gene cause microcephaly and neurological dysfunction. The mouse model for DYRK1A haploinsufficiency (the Dyrk1a(+/-) mouse) presents neuronal deficits in specific regions of the adult brain, including the substantia nigra (SN), although the mechanisms underlying these pathogenic effects remain unclear. Here we study the effect of DYRK1A copy number variation on dopaminergic cell homeostasis. We show that mesencephalic DA (mDA) neurons are generated in the embryo at normal rates in the Dyrk1a haploinsufficient model and in a model (the mBACtgDyrk1a mouse) that carries three copies of Dyrk1a. We also show that the number of mDA cells diminishes in postnatal Dyrk1a(+/-) mice and increases in mBACtgDyrk1a mice due to an abnormal activity of the mitochondrial caspase9 (Casp9)-dependent apoptotic pathway during the main wave of PCD that affects these neurons. In addition, we show that the cell death induced by 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP), a toxin that activates Casp9-dependent apoptosis in mDA neurons, is attenuated in adult mBACtgDyrk1a mice, leading to an increased survival of SN DA neurons 21 days after MPTP intoxication. Finally, we present data indicating that Dyrk1a phosphorylation of Casp9 at the Thr125 residue is the mechanism by which this kinase hinders both physiological and pathological PCD in mDA neurons. These data provide new insight into the mechanisms that control cell death in brain DA neurons and they show that deregulation of developmental apoptosis may contribute to the phenotype of patients with imbalanced DYRK1A gene dosage.
Insights
Dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A) copy number affects dopaminergic neuron survival. DYRK1A regulates programmed cell death (PCD) by phosphorylating caspase-9, impacting neurodevelopment and neurodegeneration.
Area of Science:
- Neuroscience
- Developmental Biology
- Genetics
Background:
- Programmed cell death (PCD) is crucial for neural development and its dysregulation causes neurodegeneration.
- Dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A) is vital for brain growth and is implicated in neural proliferation and cell death.
- DYRK1A gene dosage variations are linked to neurological dysfunction, particularly in Down syndrome.
Purpose of the Study:
- To investigate the impact of DYRK1A copy number variations on dopaminergic neuron homeostasis.
- To elucidate the role of DYRK1A in regulating programmed cell death pathways in midbrain dopaminergic (mDA) neurons.
- To understand the mechanism by which DYRK1A influences neuronal survival in both physiological and pathological contexts.
Main Methods:
- Utilized mouse models with altered Dyrk1a gene dosage (haploinsufficiency and triplication).
- Assessed the generation and survival rates of midbrain dopaminergic (mDA) neurons during embryonic and postnatal development.
- Investigated the involvement of the mitochondrial caspase-9 (Casp9)-dependent apoptotic pathway.
- Examined the effects of MPTP (1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine) intoxication on dopaminergic neuron survival in Dyrk1a-altered mice.
- Analyzed Dyrk1a phosphorylation of Casp9 at the Thr125 residue.
Main Results:
- Dyrk1a haploinsufficiency led to a decrease, while Dyrk1a triplication increased, the number of postnatal mDA neurons.
- DYRK1A copy number variations altered the activity of the Casp9-dependent apoptotic pathway during critical PCD waves.
- Adult mice with Dyrk1a triplication exhibited reduced cell death and increased survival of substantia nigra (SN) DA neurons following MPTP intoxication.
- Dyrk1a directly phosphorylates Casp9 at Thr125, inhibiting both physiological and pathological PCD in mDA neurons.
Conclusions:
- DYRK1A copy number is a critical determinant of dopaminergic neuron survival.
- Dysregulation of DYRK1A-mediated control over the Casp9 apoptotic pathway contributes to neurodevelopmental and neurodegenerative processes.
- Imbalanced DYRK1A gene dosage can lead to neurological phenotypes through altered developmental apoptosis in dopaminergic neurons.
More Related Videos
Related Concept Videos
01:24Parkinson Disease ll: Pathophysiology
01:24Parkinson's Disease: Treatment
Parkinson's Disease is primarily a result of the loss of dopaminergic neurons in the substantia nigra pars compacta. The cornerstone of...
01:24Parkinson Disease l: Introduction
01:15Parkinson's Disease: Overview
01:37Neural Regulation