Abstract
Background: Melanoma-associated antigen D1 (Maged1) is expressed in most adult tissues, predominantly in the brain, and has critical functions in the central nervous system in both developmental and adult stages. Loss of Maged1 in mice has been linked to depression, cognitive disorder, circadian rhythm, and drug addiction. However, the role of Maged1 in Parkinson’s disease (PD) remains unclear.Methods: Immunostaining was performed to investigate the expression of Maged1 in the samples from mice and human. To make the acute mice model of PD, C57BL/6 mice and Maged1 knockout mice were injected with 20 mg/kg 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) four times, every 2-hour intervals. SY5Y cells were treated by 200 μM 1-Methyl-4-phenylpyridinium iodide (MPP+). To examine motor balance and coordination, the rotarod test and pole test were used. Then we further investigated the role of Maged1 deficiency in DA neurons by high-performance liquid chromatography, immunohistochemistry, western blot, CCK8 assay, and gene transfection in vivo or in vitro.Results: Maged1 was expressed in DA neurons of samples from mice and human. And the expression of Maged1 was time-dependently upregulated by the treatment with MPTP or MPP+ in vivo or in vitro. Knockout of Maged1 in mice partly rescued the motor deficits and the reduced levels of striatal dopamine and its metabolites by MPTP treatment. Moreover, Maged1 deficiency protected primary DA neurons and differentiated ReNcell VM cells from MPP+ toxicity. Furthermore, along with the overexpression or downregulation of Maged1 in cultured SH-SY5Y cells, the reduced the cell viability by MPP+ treatment was relatively aggerated or attenuated. The effect of Maged1 deficiency may be attributed to the upregulated Akt signaling pathway and the downregulated mTOR signaling pathway, which further attenuated the MPTP or MPP+ -induced cell apoptosis and impairment of autophagy. Consistent with the above data, the degeneration of midbrain and striatum among 15-m Maged1 knockout mice was relatively mild compared to those in 15-m wild-type mice under physiological conditions.Conclusions: Maged1 deficiency-mediated apoptosis inhibition and autophagy enhancement may be a potential pro-survival mechanism during the progression of PD.
Neuroprotective effects of protocatechuic aldehyde through PLK2/p-GSK3β/Nrf2 signaling pathway in both in vivo and in vitro models of Parkinson's disease
