Neuronal pigmented autophagic vacuoles: lipofuscin, neuromelanin, and ceroid as macroautophagic responses during aging and disease

J Neurochem. 2008 Jul;106(1):24-36. doi: 10.1111/j.1471-4159.2008.05385.x. Epub 2008 Apr 1.

Abstract

The most striking morphologic change in neurons during normal aging is the accumulation of autophagic vacuoles filled with lipofuscin or neuromelanin pigments. These organelles are similar to those containing the ceroid pigments associated with neurologic disorders, particularly in diseases caused by lysosomal dysfunction. The pigments arise from incompletely degraded proteins and lipids principally derived from the breakdown of mitochondria or products of oxidized catecholamines. Pigmented autophagic vacuoles may eventually occupy a major portion of the neuronal cell body volume because of resistance of the pigments to lysosomal degradation and/or inadequate fusion of the vacuoles with lysosomes. Although the formation of autophagic vacuoles via macroautophagy protects the neuron from cellular stress, accumulation of pigmented autophagic vacuoles may eventually interfere with normal degradative pathways and endocytic/secretory tasks such as appropriate response to growth factors.

Publication types

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

MeSH terms

  • Aging / metabolism*
  • Animals
  • Autophagy / physiology*
  • Brain / metabolism*
  • Brain / pathology
  • Brain / ultrastructure
  • Brain Diseases / metabolism*
  • Brain Diseases / pathology
  • Ceroid / metabolism
  • Coloring Agents / metabolism
  • Humans
  • Lipofuscin / metabolism
  • Melanins / metabolism
  • Neurons / metabolism*
  • Neurons / pathology
  • Neurons / ultrastructure
  • Vacuoles / metabolism*
  • Vacuoles / pathology
  • Vacuoles / ultrastructure

Substances

  • Ceroid
  • Coloring Agents
  • Lipofuscin
  • Melanins
  • neuromelanin