Glycogen accumulation underlies neurodegeneration and autophagy impairment in Lafora disease.
Lafora disease is a fatal neurodegenerative condition characterized by the accumulation of abnormal glycogen inclusions known as Lafora bodies. It is an autosomal recessive disorder caused by mutations in either the laforin or malin gene. To study whether glycogen is primarily responsible for the neurodegeneration in Lafora disease, we generated malin knockout mice with impaired (totally or partially) glycogen synthesis. These animals did not show the increase in markers of neurodegeneration, the impairments in electrophysiological properties of hippocampal synapses, nor the susceptibility to kainate-induced epilepsy seen in the malin knockout model. Interestingly, the autophagy impairment that has been described in malin knockout animals was also rescued in this double knockout model. Conversely, two other mouse models in which glycogen is over-accumulated in the brain independently of the lack of malin showed impairment in autophagy. Our findings reveal that glycogen accumulation accounts for the neurodegeneration and functional consequences seen in the malin knockout model, as well as the impaired autophagy. These results identify the regulation of glycogen synthesis as a key target for the treatment of Lafora disease.
Institute for Research in Biomedicine (IRB Barcelona), Barcelona 08028, Spain Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona 08017, Spain.
Jordi
J
Duran
Division of Neurosciences, Pablo de Olavide University, Seville 41013, Spain.
Agnès
A
Gruart
Institute for Research in Biomedicine (IRB Barcelona), Barcelona 08028, Spain.
Mar
M
García-Rocha
Division of Neurosciences, Pablo de Olavide University, Seville 41013, Spain.
José M
JM
Delgado-García
Institute for Research in Biomedicine (IRB Barcelona), Barcelona 08028, Spain Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona 08017, Spain Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona 08028, Spain guinovart@irbbarcelona.org.
Joan J
JJ
Guinovart
D000818:Animals; D001343:Autophagy; D015415:Biomarkers / Q000378:metabolism; D004195:Disease Models, Animal; D054637:Dual-Specificity Phosphatases / Q000378:metabolism*; D054351:Electrical Synapses / Q000378:metabolism; D004827:Epilepsy / Q000139:chemically induced / Q000473:pathology; D006003:Glycogen / Q000378:metabolism*; D006006:Glycogen Synthase / Q000235:genetics* / Q000378:metabolism; D006624:Hippocampus / Q000502:physiology; D006801:Humans; D002479:Inclusion Bodies / Q000235:genetics / Q000378:metabolism; D007608:Kainic Acid / Q000494:pharmacology; D020192:Lafora Disease / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation; D054558:Protein Tyrosine Phosphatases, Non-Receptor; D044767:Ubiquitin-Protein Ligases / Q000235:genetics* / Q000378:metabolism
D015415:Biomarkers; D006003:Glycogen; C572596:NHLRC1 protein, mouse; D044767:Ubiquitin-Protein Ligases; D006006:Glycogen Synthase; D054637:Dual-Specificity Phosphatases; C491989:Epm2a protein, mouse; D054558:Protein Tyrosine Phosphatases, Non-Receptor; D007608:Kainic Acid