Effect of Melatonin on Alpha Synuclein and Autophagy in Dopaminergic Neuronal Differentiation of Adipose Mesenchymal Stem Cells

The current work investigated the effect of melatonin on differentiation of adipose mesenchymal stem cells (AD-MSCs) into dopamine producing cells and its effect on autophagy process and alpha-Synuclein (α-Syn) secretion. 

AD-MSCs were characterized by flow cytometry and divided into 4 groups; i) control group (AD-MSCs without any treatment), ii) M+MSCs group (MSCs treated with 1 µM melatonin for 12 days), iii) DN group (MSCs cultured in neurobasal A medium and essential neuronal growth factors for 12 days) and iv) DN+M group (MSCs cultured in neurobasal A medium and 1µM melatonin for 12 days. By the end of experiments, the dopamine and α-Syn levels using ELISA, the expression of MAP-2, m-TOR and α-Syn genes at the level of mRNA and detection of autophagosomes formation using transmission electron microscope were performed. 

We found that the isolated cells were MSCs due to their positivity expression for CD105 and CD90 and negativity expression for CD34 and CD45. The concentration of dopamine was significantly higher and α-Syn concentration was significantly lower in DN+M group when compared to other groups (P< 0.005). Also, this group showed the highly expression for MAP-2 gene and less expression for m-TOR and α-Syn genes (P< 0.005). Moreover, there was significantly increase in autophagosomes formation in this group than another group (P< 0.005). 

It is concluded that the melatonin promotes the differentiation of rat AD-MSCs into dopaminergic cells via induction of autophagy process and reduction of α-Syn secretion.