Dendrobine inhibits dopaminergic neuron apoptosis via MANF-mediated ER stress suppression in MPTP/MPP+-induced Parkinson's disease models

Background: Parkinson's disease (PD) is an age-related neurodegenerative disorder without effective treatments. Mesencephalic astrocyte-derived neurotrophic factor (MANF) has been suggested to be capable of protecting against PD by inhibiting endoplasmic reticulum (ER) stress-mediated neuronal apoptosis. Purpose: This study was aimed to evaluate the antiparkinsonian effect of dendrobine and reveal its underlying mechanisms from the perspective of MANF-mediated ER stress suppression. Methods: Behavioral assessments of PD mice as well as LDH/CCK-8 assay in SH-SY5Y cells and primary midbrain neurons were carried out to detect the antiparkinsonian effect of dendrobine. Immunofluorescence, western blot, flow cytometry and shRNA-mediated MANF knockdown were used to determine the apoptosis of dopaminergic neurons and the expressions of ER stress-related proteins for investigating the underlying mechanism of dendrobine. Results: Dendrobine significantly ameliorated the motor performance of PD mice and attenuated the injuries of dopaminergic neurons. Dendrobine could also relieve neuronal apoptosis, up-regulate MANF expression and inhibit ER stress, which were largely abolished by shRNA-mediated MANF knockdown in PD model. Conclusion: Dendrobine might protect against PD by inhibiting dopaminergic neuron apoptosis, which was achieved by facilitating MANF-mediated ER stress suppression. Our study suggested that dendrobine could act as a MANF up-regulator to protect against PD, and provided a potential candidate for exploring etiological agents of PD.