Irisin protect the Dopaminergic neurons of the Substantia nigra in the rat model of Parkinson’s disease

Exercise ameliorates the quality of life and reduces the risk of neurological derangements such as Alzheimer’s (AD) and Parkinson’s disease (PD). Irisin is a product of the physical activity and is a circulating hormone that regulates the energy metabolism in the body. In the nervous system, Irisin influences neurogenesis and neural differentiation in mice. We previously demonstrated that co-treatment of bone marrow stem cells (BMSCs) with a neurotrophic factor reduce Parkinson’s symptoms. Our goal in this project was to evaluate whether Irisin with BMSCs can protect the dopaminergic (DA) neurons in PD. 35 adult male Wistar rat weighing (200-250 g) were chosen. They were separated into five experimental groups (n=7). To create a Parkinson’s model, intranasal (IN) administration of the MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) was used. The BMSCs (2×106) and Irisin (50 nm/ml) was used for 7 days for treatment after creation of the PD model. After completion of the tests (4 weeks), their brains were used for the TUNEL and immunohistochemical (IHC) assays. One of the important results of this study was that the Irisin induce BMSCs transport into the injured area of the brain. Co-treatment of the Irisin with BMSCs increased tyrosine hydroxylase-positive neurons (TH+) in substantia nigra (SN) and striatum of the PD mice brain. In this group, the number of TUNEL-positive cells significantly decreased. Behavioral symptoms were better in the combination group and Irisin simultaneously. Co- treatment of Irisin with BMSCs protects the DA neurons from degeneration and apoptotic process after MPTP injection.