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Cultured porcine trabecular meshwork cells display altered lysosomal function when subjected to chronic oxidative stress.

Publication ,  Journal Article
Liton, PB; Lin, Y; Luna, C; Li, G; Gonzalez, P; Epstein, DL
Published in: Invest Ophthalmol Vis Sci
September 2008

PURPOSE: To investigate the effects of chronic oxidative stress on lysosomal function in trabecular meshwork (TM) cells. METHODS: Confluent cultures of porcine TM cells were grown for 2 weeks in physiological (5% O(2)) or hyperoxic conditions (40% O(2)) in the presence or absence of the protease inhibitor leupeptin (10 microM). The following parameters were quantified using the fluorogenic probes indicated within parentheses: autofluorescence, intracellular reactive oxygen species (ROS; H(2)DCFDA), mitochondrial membrane potential (JC-1), mitochondrial content (Mitotracker Red; Invitrogen-Molecular Probes, Eugene, OR), lysosomal content (acridine orange and Lysotracker Red [Invitrogen-Molecular Probes]), autophagic vacuole content (MDC), SA-beta-galactosidase (FDG), and cathepsin activities (z-FR-AMC). Cathepsin levels were quantified by qPCR and Western blot analysis. Ultrastructural analysis was performed by transmission electron microscopy. RESULTS: Prolonged exposure of porcine TM cells to a hyperoxic environment led to an increase in ROS production and oxidized material. Electron micrographs revealed the cytoplasmic accumulation of lipofuscin-loaded lysosomes. Augmented lysosomal and autophagic vacuole content was confirmed with specific fluorophores. The mRNA and protein levels of several cathepsins were upregulated with oxidative stress. This upregulated expression did not correlate with increased lysosomal activity. CONCLUSIONS: The results indicate that chronic exposure of TM cells to oxidative stress causes the accumulation of nondegradable material within the lysosomal compartment, leading to diminished lysosomal activity. Since the lysosomal system is responsible for the continuous turnover of cellular organelles, impaired lysosomal activity may lead to progressive failure of cellular TM function with age.

Duke Scholars

Published In

Invest Ophthalmol Vis Sci

DOI

EISSN

1552-5783

Publication Date

September 2008

Volume

49

Issue

9

Start / End Page

3961 / 3969

Location

United States

Related Subject Headings

  • Vacuoles
  • Trabecular Meshwork
  • Swine
  • Polymerase Chain Reaction
  • Oxygen
  • Oxidative Stress
  • Ophthalmology & Optometry
  • Mitochondrial Membranes
  • Membrane Potentials
  • Lysosomes
 

Citation

APA
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ICMJE
MLA
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Liton, P. B., Lin, Y., Luna, C., Li, G., Gonzalez, P., & Epstein, D. L. (2008). Cultured porcine trabecular meshwork cells display altered lysosomal function when subjected to chronic oxidative stress. Invest Ophthalmol Vis Sci, 49(9), 3961–3969. https://doi.org/10.1167/iovs.08-1915
Liton, Paloma B., Yizhi Lin, Coralia Luna, Guorong Li, Pedro Gonzalez, and David L. Epstein. “Cultured porcine trabecular meshwork cells display altered lysosomal function when subjected to chronic oxidative stress.Invest Ophthalmol Vis Sci 49, no. 9 (September 2008): 3961–69. https://doi.org/10.1167/iovs.08-1915.
Liton PB, Lin Y, Luna C, Li G, Gonzalez P, Epstein DL. Cultured porcine trabecular meshwork cells display altered lysosomal function when subjected to chronic oxidative stress. Invest Ophthalmol Vis Sci. 2008 Sep;49(9):3961–9.
Liton, Paloma B., et al. “Cultured porcine trabecular meshwork cells display altered lysosomal function when subjected to chronic oxidative stress.Invest Ophthalmol Vis Sci, vol. 49, no. 9, Sept. 2008, pp. 3961–69. Pubmed, doi:10.1167/iovs.08-1915.
Liton PB, Lin Y, Luna C, Li G, Gonzalez P, Epstein DL. Cultured porcine trabecular meshwork cells display altered lysosomal function when subjected to chronic oxidative stress. Invest Ophthalmol Vis Sci. 2008 Sep;49(9):3961–3969.

Published In

Invest Ophthalmol Vis Sci

DOI

EISSN

1552-5783

Publication Date

September 2008

Volume

49

Issue

9

Start / End Page

3961 / 3969

Location

United States

Related Subject Headings

  • Vacuoles
  • Trabecular Meshwork
  • Swine
  • Polymerase Chain Reaction
  • Oxygen
  • Oxidative Stress
  • Ophthalmology & Optometry
  • Mitochondrial Membranes
  • Membrane Potentials
  • Lysosomes