Peroxisomal dysfunctions cause lysosomal storage and axonal Kv1 channel redistribution in peripheral neuropathy

• Main Authors: Sandra Kleinecke, Sarah Richert, Livia de Hoz, Britta Brügger, Theresa Kungl, Ebrahim Asadollahi, Susanne Quintes, Judith Blanz, Rhona McGonigal, Kobra Naseri, Michael W Sereda, Timo Sachsenheimer, Christian Lüchtenborg, Wiebke Möbius, Hugh Willison, Myriam Baes, Klaus-Armin Nave, Celia Michèle Kassmann
• Format: Article
• Language: English
• Published: eLife Sciences Publications Ltd 2017-05-01
• Series: eLife
• Subjects: peripheral neuropathy; peroxisomes; lysosomes; metabolic disorders; axo-glia interaction; myelin
• Online Access: https://elifesciences.org/articles/23332

Impairment of peripheral nerve function is frequent in neurometabolic diseases, but mechanistically not well understood. Here, we report a novel disease mechanism and the finding that glial lipid metabolism is critical for axon function, independent of myelin itself. Surprisingly, nerves of Schwann cell-specific Pex5 mutant mice were unaltered regarding axon numbers, axonal calibers, and myelin sheath thickness by electron microscopy. In search for a molecular mechanism, we revealed enhanced abundance and internodal expression of axonal membrane proteins normally restricted to juxtaparanodal lipid-rafts. Gangliosides were altered and enriched within an expanded lysosomal compartment of paranodal loops. We revealed the same pathological features in a mouse model of human Adrenomyeloneuropathy, preceding disease-onset by one year. Thus, peroxisomal dysfunction causes secondary failure of local lysosomes, thereby impairing the turnover of gangliosides in myelin. This reveals a new aspect of axon-glia interactions, with Schwann cell lipid metabolism regulating the anchorage of juxtaparanodal Kv1-channels.