DLP1‐dependent mitochondrial fragmentation and redistribution mediate prion‐associated mitochondrial dysfunction and neuronal death |
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| Authors: | Chaosi Li Di Wang Wei Wu Wei Yang Syed Zahid Ali Shah Ying Zhao Yuhan Duan Lu Wang Xiangmei Zhou Deming Zhao Lifeng Yang |
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| Affiliation: | National Animal Transmissible Spongiform Encephalopathy Laboratory, State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology and Zoonosis, College of Veterinary Medicine, Ministry of Agriculture, China Agricultural University, Beijing, China |
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| Abstract: | Mitochondrial malfunction is a universal and critical step in the pathogenesis of many neurodegenerative diseases including prion diseases. Dynamin‐like protein 1 (DLP1) is one of the key regulators of mitochondrial fission. In this study, we investigated the role of DLP1 in mitochondrial fragmentation and dysfunction in neurons using in vitro and in vivo prion disease models. Mitochondria became fragmented and redistributed from axons to soma, correlated with increased mitochondrial DLP1 expression in murine primary neurons (N2a cells) treated with the prion peptide PrP106–126 in vitro as well as in prion strain‐infected hamster brain in vivo. Suppression of DLP1 expression by DPL1 RNAi inhibited prion‐induced mitochondrial fragmentation and dysfunction (measured by ADP/ATP ratio, mitochondrial membrane potential, and mitochondrial integrity). We also demonstrated that DLP1 RNAi is neuroprotective against prion peptide in N2a cells as shown by improved cell viability and decreased apoptosis markers, caspase 3 induced by PrP106–126. On the contrary, overexpression of DLP1 exacerbated mitochondrial dysfunction and cell death. Moreover, inhibition of DLP1 expression ameliorated PrP106–126‐induced neurite loss and synaptic abnormalities (i.e., loss of dendritic spine and PSD‐95, a postsynaptic scaffolding protein as a marker of synaptic plasticity) in primary neurons, suggesting that altered DLP1 expression and mitochondrial fragmentation are upstream events that mediate PrP106–126‐induced neuron loss and degeneration. Our findings suggest that DLP1‐dependent mitochondrial fragmentation and redistribution plays a pivotal role in PrPSc‐associated mitochondria dysfunction and neuron apoptosis. Inhibition of DLP1 may be a novel and effective strategy in the prevention and treatment of prion diseases. |
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| Keywords: | dynamin‐like protein 1 mitochondrial dynamics neuronal degeneration prion disease |
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