Investigation of Plasma PGC1-α, Irisin, BDNF, GAL, and GALP Levels in Parkinson's Disease

Abstract

The roles of novel peptides such as transcription cofactor peroxisome proliferator 1-alpha (PGC1-α), irisin, brain-derived neurotrophic factor (BDNF), galanin (GAL) and galanin-like peptide (GALP) in Parkinson's disease (PD) are not fully known. This study, plasma levels of the novel peptides that may affect the pathophysiology of PD were examined. The study was conducted as a cross-sectional. The study consisted of two groups, including 45 newly diagnosed patients with idiopathic PD and 45 healthy individuals. The peptide levels in plasma samples collected from the groups were measured by the ELISA method. The means ages of both groups were over 65 years old and the age difference was insignificant. When plasma PGC1-α, irisin, BDNF, GAL, and GALP levels between the groups were examined, it was determined that the median levels of the patient group (3.38[2.60-4.43]ng/mL, 12.77[9.70-15.04]ng/mL, 1.61[1.35-2.01]ng/mL, 15.46[12.98-17.77]ng/L, and 47.68[32.5-65.86]pg/mL, respectively) were lower compared to the control group (5.98[4.99-7.03]ng/mL, 18.77[15.01- 20.53]ng/mL, 4.39[3.70-4.95]ng/mL, 21.32[16.70-25.87]ng/L, and 48.92[28.66-69.68]pg/mL, respectively). While significant positive low correlations were found between plasma BDNF levels and GAL and irisin, significant positive moderate correlations were found between plasma PGC1-α levels and BDNF, irisin and GAL. A significant negative correlation was found between age and BNDF levels. As far as we know, the study is the first report in the literature in which the aforementioned peptides associated with PD were examined together. We consider that more detailed studies are needed to shed light on the roles and mechanisms of these peptides in PD.