resolvin-d1 and Parkinson-Disease

Neuroinflammation is one of the hallmarks of Parkinson's disease (PD) and may contribute to midbrain dopamine (DA) neuron degeneration. Recent studies link chronic inflammation with failure to resolve early inflammation, a process operated by specialized pro-resolving mediators, including resolvins. However, the effects of stimulating the resolution of inflammation in PD - to modulate disease progression - still remain unexplored. Here we show that rats overexpressing human α-synuclein (Syn) display altered DA neuron properties, reduced striatal DA outflow and motor deficits prior to nigral degeneration. These early alterations are coupled with microglia activation and perturbations of inflammatory and pro-resolving mediators, namely IFN-γ and resolvin D1 (RvD1). Chronic and early RvD1 administration in Syn rats prevents central and peripheral inflammation, as well as neuronal dysfunction and motor deficits. We also show that endogenous RvD1 is decreased in human patients with early-PD. Our results suggest there is an imbalance between neuroinflammatory and pro-resolving processes in PD.

Topics: alpha-Synuclein; Animals; Disease Models, Animal; Docosahexaenoic Acids; Dopaminergic Neurons; Humans; Inflammation; Male; Microglia; Nerve Degeneration; Parkinson Disease; Rats; Rats, Sprague-Dawley; Rats, Transgenic; Substantia Nigra

BACKGROUND We investigated the influence of Resolvin D1 (RvD1) on the inflammatory response in PC12 cells (a cell model of Parkinson disease, PD). MATERIAL AND METHODS 4 mmol/L 1-methyl-4-phenylpyridinium ion (Mpp+) was used in PC12 cells for an in vitro PD model. 3-(4,5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay was used to explore PC12 cell viability. Western blot (WB) experiments were used to identify nuclear factor-κB (NF-κB), phosphorylated extracellular signal-regulated kinase (p-ERK)/p-Jun N-terminal kinase (JNK)/p-P38 mitogen-activated protein kinase (MAPK), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 protein levels. Transcription levels of inflammatory factors, for instance, TNF-α and IL-6, were explored by real-time quantitative polymerase chain reaction (RT-QPCR). Lactic dehydrogenase (LDH) level was detected by enzyme-linked immunosorbent (ELISA). Cell apoptosis was assessed by Annexin-V Fluorescein (FITC) kit. RESULTS RvD1 dose-dependently inhibited MPP+ induced upregulation of PC12 cell apoptosis/cellular damage/TNF-α and p-P38/p-ERK/NF-κB as well as downregulation of PC12 cell viability. CONCLUSIONS We can draw the conclusion that RvD1 attenuates PD via inhibiting Mpp+-induced inflammation in PC12 cells.

Topics: 1-Methyl-4-phenylpyridinium; Animals; Apoptosis; Disease Models, Animal; Docosahexaenoic Acids; Extracellular Signal-Regulated MAP Kinases; Flow Cytometry; Inflammation; Interleukin-6; MAP Kinase Kinase 4; MAP Kinase Signaling System; NF-kappa B; p38 Mitogen-Activated Protein Kinases; Parkinson Disease; PC12 Cells; Phosphorylation; Rats; Tumor Necrosis Factor-alpha; Up-Regulation