Browsing by Subject "brain-derived neurotrophic factor (BDNF)"

Parkinson’s disease (PD) is a progressive neurodegenerative disorder with the neuropathological hallmark of intraneuronal inclusions called Lewy bodies (LB). Accumulation of α-synuclein (α-syn) and cellular components into LBs coincides with degeneration of dopaminergic neurons in the midbrain, substantia nigra. Degeneration of dopaminergic neurons eventually leads to motor dysfunctions. Currently, the treatments for PD are symptomatic. For this reason, new disease-modifying treatments are needed to slow down or prevent the disease progression. Neurotrophic factors (NTFs) have been an interest of research for a couple of decades because of their neuroprotective properties. The main aim of this study was to investigate if brain-derived neurotrophic factor (BDNF) reduces pre-formed fibril (PFF) induced aggregation of α-syn in dopaminergic neurons. PFF-model was used to mimic the accumulation of LBs in neurons, as PFFs induce aggregation of endogenous α-syn in neurons. Additionally, the dose dependence of BDNF was tested. The secondary objective was to investigate the interaction of tropomyosin receptor kinase B (TrkB) signaling pathway and α-syn aggregation using TrkB agonists and antagonists. The cultured dopaminergic neurons isolated from the midbrain of mouse embryos were treated with PFFs on the day in vitro (DIV) 8. BDNF or control treatments were added either 1 hour after the PFF-treatment or on DIV 12. Neurons were fixed on DIV 15 and fluorescent immunohistochemistry was performed. After the detection of fluorescence with automated, high-content imaging, image analysis was done for quantifying dopaminergic neurons, and dopaminergic neurons positive for LB-like aggregates by using unbiased image analysis CellProfilerTM software. Both BDNF and positive control glial cell line-derived neurotrophic factor (GDNF) significantly reduced LB-like aggregates in dopaminergic neurons at both timepoints. GDNF was more effective at both timepoints than BDNF. Both tested doses of BDNF lowered the number of LB-like aggregates, but a more robust effect was seen with the higher dose. The highest tested dose for the TrkB agonists was toxic to the cultured dopaminergic neurons, whereas the lower doses did not affect either the survival or the number of LB-like aggregates. BDNF promoted the survival of the dopaminergic neurons despite the survival-reducing adverse effect of TrkB antagonist K252a. This study provided new information on the effects of exogenously added BDNF on PFF-model with primary neuronal culture. Research on the underlying mechanisms of α-syn aggregation and the protective effects of NTFs can forward the development of new therapies against PD.