Astrocytic glycogen accumulation drives the pathophysiology of neurodegeneration in Lafora disease

Brain. 2021 Sep 4;144(8):2349-2360. doi: 10.1093/brain/awab110.

Abstract

The hallmark of Lafora disease, a fatal neurodegenerative disorder, is the accumulation of intracellular glycogen aggregates called Lafora bodies. Until recently, it was widely believed that brain Lafora bodies were present exclusively in neurons and thus that Lafora disease pathology derived from their accumulation in this cell population. However, recent evidence indicates that Lafora bodies are also present in astrocytes. To define the role of astrocytic Lafora bodies in Lafora disease pathology, we deleted glycogen synthase specifically from astrocytes in a mouse model of the disease (malinKO). Strikingly, blocking glycogen synthesis in astrocytes-thus impeding Lafora bodies accumulation in this cell type-prevented the increase in neurodegeneration markers, autophagy impairment, and metabolic changes characteristic of the malinKO model. Conversely, mice that over-accumulate glycogen in astrocytes showed an increase in these markers. These results unveil the deleterious consequences of the deregulation of glycogen metabolism in astrocytes and change the perspective that Lafora disease is caused solely by alterations in neurons.

Keywords: Lafora disease; epilepsy; glycogen; neurodegeneration; neuroinflammation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes / metabolism*
  • Astrocytes / pathology
  • Brain / metabolism*
  • Brain / pathology
  • Disease Models, Animal
  • Glycogen / metabolism*
  • Glycogen Synthase / genetics
  • Glycogen Synthase / metabolism
  • Lafora Disease / genetics
  • Lafora Disease / metabolism*
  • Lafora Disease / pathology
  • Mice
  • Mice, Knockout
  • Nerve Degeneration / genetics
  • Nerve Degeneration / metabolism*
  • Nerve Degeneration / pathology
  • Neurons / metabolism
  • Neurons / pathology
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism

Substances

  • Glycogen
  • NHLRC1 protein, mouse
  • Ubiquitin-Protein Ligases
  • Glycogen Synthase