Abstract
Insulin-like growth factor 2 (IGF2) and autophagy-related genes have been proposed as interesting biomolecules related to idiopathic Parkinson’s disease (PD). The objective of this study was to determine the IGF2 and IGF1 levels in plasma and peripheral blood mononuclear cells (PBMCs) from patients with moderately advanced PD and explore the potential correlation with autophagy-related genes in the same blood samples. IGF1 and IGF2 levels in patients' plasma were measured by ELISA, and the IGF2 expression levels were determined by real-time PCR and Western blot in PBMCs. The expression of autophagy-related genes was evaluated by real-time PCR. The results show a significant decrease in IGF2 plasma levels in PD patients compared with a healthy control group. We also report a dramatic decrease in IGF2 mRNA and protein levels in PBMCs from PD patients. In addition, we observed a downregulation of key components of the initial stages of the autophagy process. Although IGF2 levels were not directly correlated with disease severity, we found a correlation between its levels and autophagy genes expression from the same samples, in a sex-dependent manner. To further explore this correlation, we treated mice macrophages cell culture with α-synuclein and IGF2. While α-synuclein treatment decreased levels of Beclin1 and Atg5, IGF2 treatment reverted these effects. Our results suggest a relationship between IGF2 levels and the autophagy process in PD and its potential application as a multi-biomarkers to determine the PD patients' stages of the disease.
Is insulin-like growth factor-1 involved in Parkinson’s disease development?