June 1995
Volume 36, Issue 7
Free
Articles  |   June 1995
Phagocytosis and H2O2 induce catalase and metallothionein gene expression in human retinal pigment epithelial cells.
Author Affiliations
  • D J Tate, Jr
    Sensory and Electrophysiology Research Unit, Touro Infirmary, New Orleans, LA 70115, USA.
  • M V Miceli
    Sensory and Electrophysiology Research Unit, Touro Infirmary, New Orleans, LA 70115, USA.
  • D A Newsome
    Sensory and Electrophysiology Research Unit, Touro Infirmary, New Orleans, LA 70115, USA.
Investigative Ophthalmology & Visual Science June 1995, Vol.36, 1271-1279. doi:
  • Views
  • PDF
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      D J Tate, M V Miceli, D A Newsome; Phagocytosis and H2O2 induce catalase and metallothionein gene expression in human retinal pigment epithelial cells.. Invest. Ophthalmol. Vis. Sci. 1995;36(7):1271-1279.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

PURPOSE: Reactive oxygen intermediates have been implicated in the aging process and degenerative diseases of the eye, including retinopathy of prematurity, cataractogenesis, and macular degeneration. The purpose of this study was to investigate the effect of phagocytosis of photoreceptor outer segments and the addition of exogenous H2O2 on catalase and metallothionein expression in human retinal pigment epithelial cells. METHODS: Confluent RPE cells were treated with bovine photoreceptor outer segments or H2O2 for either 6 or 18 hours. Slot blot hybridization was used to assess catalase and metallothionein gene expression after 6 hours. Catalase enzyme activity and metallothionein content were measured after 18 hours. RESULTS: Phagocytosis or the addition of H2O2 increased catalase enzyme activity and metallothionein twofold above control levels. The addition of n-acetyl cysteine abrogated the inductive effect caused by either stress. Catalase and metallothionein gene expression, measured by slot blot hybridization, also were measurably induced by either stress. Phagocytosis of photoreceptor outer segments increased extracellular H2O2 concentration nine times above control. CONCLUSIONS: The response of the retinal pigment epithelial cells to phagocytosis was indistinguishable from the response observed after the addition of exogenous H2O2. The generation of H2O2 during phagocytosis may act as an intracellular signal in retinal pigment epithelial cells that leads to increased levels of key antioxidant enzymes and other proteins important for protecting the cells from oxidative damage.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×