The loss of dopaminergic neurons in DEC1 deficient mice potentially involves the decrease of PI3K/Akt/GSK3β signaling

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Differentiated embryonic chondrocyte gene 1 (DEC1) plays a role in cellular processes.
• Midbrain dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc) are crucial for motor control.
• Parkinson's disease (PD) is characterized by the progressive loss of these DA neurons.

Purpose of the Study:

• To investigate the impact of DEC1 deficiency on DA neurons in the SNpc.
• To explore the potential mechanisms underlying DA neuron loss in DEC1-deficient mice.
• To assess the therapeutic potential of targeting related signaling pathways.

Main Methods:

• Behavioral analysis (locomotor activity, motor coordination, spatial learning/memory) in DEC1 knockout (KO) and wild-type (WT) mice.
• Histological examination of SNpc for DA neuron counts and cell death markers (activated caspase-3, TH/TUNEL+, NeuN/TUNEL+).
• Molecular analysis of dopamine and its metabolites in the striatum and assessment of the PI3K/Akt/GSK3β signaling pathway.

Main Results:

• DEC1 KO mice exhibited decreased locomotor activity and motor coordination, resembling PD symptoms, but normal spatial memory.
• Significant loss of DA neurons in the SNpc and reduced dopamine levels were observed in DEC1 KO mice.
• Increased markers of apoptosis (activated caspase-3, TH/TUNEL+) in the SNpc of DEC1 KO mice, alongside inhibited PI3K/Akt/GSK3β signaling.

Conclusions:

• DEC1 deficiency leads to progressive loss of midbrain DA neurons and motor deficits, characteristic of Parkinson's disease.
• The observed DA neuron loss is associated with the downregulation of the PI3K/Akt/GSK3β signaling pathway.
• Pharmacological intervention with LiCl showed potential to rescue DA neuron loss, suggesting a therapeutic target.