Microglial overexpression of fALS-linked mutant SOD1 induces SOD1 processing impairment, activation and neurotoxicity and is counteracted by the autophagy inducer trehalose

Publication date: Available online 10 October 2018Source: Biochimica et Biophysica Acta (BBA) - Molecular Basis of DiseaseAuthor(s): Francesca Massenzio, Emiliano Peña-Altamira, Sabrina Petralla, Marco Virgili, Giampaolo Zuccheri, Andrea Miti, Elisabetta Polazzi, Ilaria Mengoni, Deborah Piffaretti, Barbara MontiAbstractAmyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease. Mutations in the gene encoding copper/zinc superoxide dismutase-1 (SOD1) are responsible for most familiar cases, but the role of mutant SOD1 protein dysfunction in non-cell autonomous neurodegeneration, especially in relation to microglial activation, is still unclear. Here, we focused our study on microglial cells, which release SOD1 also through exosomes. We observed that in rat primary microglia the overexpression of the most-common SOD1 mutations linked to fALS (G93A and A4V) leads to SOD1 intracellular accumulation, which correlates to autophagy dysfunction and microglial activation. In primary contact co-cultures, fALS mutant SOD1 overexpression by microglial cells appears to be neurotoxic by itself. Treatment with the autophagy-inducer trehalose reduced mutant SOD1 accumulation in microglial cells, decreased microglial activation and abrogated neurotoxicity in the co-culture model. These data suggest that i) the alteration of the autophagic pathway due to mutant SOD1 overexpression is involved in microglial activation and neurotoxicity; ii) the induction of autophagy with trehalose re...
Source: Biochimica et Biophysica Acta (BBA) Molecular Basis of Disease - Category: Molecular Biology Source Type: research