Astrocytosis in infantile neuronal ceroid lipofuscinosis: friend or foe?

Biochem Soc Trans. 2014 Oct;42(5):1282-5. doi: 10.1042/BST20140188.

Abstract

Infantile neuronal ceroid lipofuscinosis (INCL; infantile Batten disease) is an inherited paediatric neurodegenerative disease. INCL is caused by a deficiency in the lysosomal enzyme palmitoyl-protein thioesterase-1 (PPT1) and is thus classified as a lysosomal storage disease. Pathological examination of both human and murine INCL brains reveals progressive, widespread neuroinflammation. In fact, astrocyte activation appears to be the first histological sign of disease. However, the role of astrocytosis in INCL was poorly understood. The hallmark of astrocyte activation is the up-regulation of intermediate filaments, such as glial fibrillary acidic protein (GFAP) and vimentin. The role of astrocytosis in INCL was studied in a murine model lacking PPT1 and the intermediate filaments GFAP and vimentin (triple-knockout). This murine model of INCL with attenuated astrocytosis had an exacerbated pathological and clinical phenotype. The triple-knockout mouse had a significantly shortened lifespan, and accelerated cellular and humoural neuroinflammatory response compared with the parental PPT1(-/-) mouse. The data obtained from the triple-knockout mouse strongly suggest that astrocyte activation plays a beneficial role in early INCL disease progression. A more thorough understanding of the glial responses to lysosomal enzyme deficiencies and the accumulation of undergraded substrates will be crucial to developing effective therapeutics.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Astrocytes / immunology
  • Astrocytes / metabolism
  • Astrocytes / pathology*
  • Gliosis / etiology*
  • Humans
  • Intermediate Filaments / immunology
  • Intermediate Filaments / metabolism
  • Intermediate Filaments / pathology
  • Membrane Proteins / deficiency
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice, Knockout
  • Mutation
  • Nerve Tissue Proteins / deficiency
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neuronal Ceroid-Lipofuscinoses / immunology
  • Neuronal Ceroid-Lipofuscinoses / metabolism
  • Neuronal Ceroid-Lipofuscinoses / pathology
  • Neuronal Ceroid-Lipofuscinoses / physiopathology*
  • Thiolester Hydrolases / genetics
  • Thiolester Hydrolases / metabolism*

Substances

  • Membrane Proteins
  • Nerve Tissue Proteins
  • Thiolester Hydrolases
  • PPT1 protein, human
  • palmitoyl-protein thioesterase