Lipofuscin

from Wikipedia, the free encyclopedia

Lipofuscin , also spelled lipofuscin and often referred to as age pigment , is a yellow-brown cross-linked aggregate, consisting of oxidized protein (30% to 58%) and lipid clusters (19% to 51%), which is particularly found in heart muscle, hepatocytes and Nerve cells, as well as in the retinal pigment epithelium (RPE), a special layer of cells in the back of the eye, accumulate over time. Lipofuscin is found primarily in the telolysosomes ( residual bodies ), vacuoles from the fusion of lysosomes with organelles or phagosomes .

It is visible microscopically in the cell nucleus as a dark field. With increasing age, this endogenous pigment thickens and discolours the skin brownish in some places. Lipofuscin arises as a waste product that cannot be further processed and is degradable through oxidative stress on proteins ( protein oxidation ) and lipids ( lipid peroxidation ). Among other things, it is stored by the heart muscle cells. The pigment is also the subject of age research .

In the clinical picture of neuronal ceroid lipofuscinosis , an overpowering accumulation of lipofuscin in nerve cells of the brain can be determined, which is regarded as the cause of nerve cell death. It is a neurodegenerative disease. In type 3 of this disease (Batten's disease), however, the majority of the accumulation consists of a lipophilic subunit of ATP synthase .

In age-related macular degeneration (AMD), there is an almost linear accumulation of lipofuszin in the RPE cells with increasing age . An excessive accumulation of lipofuszin in the RPE leads to an impairment of the function and viability of the cells of the RPE and ultimately to their death. The progressive loss of ever larger areas of the RPE ("geographic atrophy") causes the photoreceptors above it to die off. In 2012, it was found that lipofuscin can be removed from RPE cells in monkeys and humans using drugs.

Individual evidence

  1. ↑ T. Jung et al.: Lipofuscin: formation, distribution, and metabolic consequences. In: Ann. NY Acad. Sci. 1119, 2007, pp. 97-111. PMID 18056959 doi: 10.1196 / annals.1404.008 .
  2. ↑ SS Seehafer, DA Pearce: You say lipofuscin, we say ceroid: defining autofluorescent storage material. In: Neurobiol. Aging. 27, 2006, pp. 576-588. PMID 16455164 doi: 10.1016 / j.neurobiolaging.2005.12.006 .
  3. ↑ C. Behl, B. Moosmann: Molecular Mechanisms of Aging About the aging of cells and the influence of oxidative stress on the aging process. In: UM Staudinger, H. Häfner (Ed.): What is age (s)? Verlag Springer, 2008, ISBN 978-3-540-76710-7 , pp. 9-32.
  4. ↑ CLN3.  In: Online Mendelian Inheritance in Man . (English).
  5. ^ S. Julien, U. Schraermeyer: Lipofuscin can be eliminated from the retinal pigment epithelium of monkeys. In: Neurobiol Aging. 2012. (Epub ahead of print) PMID 22244091
  6. ↑ S. Julien, A. Biesemeier, P. Heiduschka, M. Rittgarn, S. Schultheiss, E. Winkler, S. Hofmeister, U. Schraermeyer: Lipofuscin can be eliminated from retinal pigment epithelium after drug treatment. ARVO, Fort Lauderdale USA, May 2010. In: Invest Ophthalmol Vis Sci. Abstract No. 481 / A45 ( Memento from July 4, 2013 in the web archive archive.today )