May 2008
Volume 49, Issue 13
Free
ARVO Annual Meeting Abstract  |   May 2008
Chronic Oxidative Stress Inhibits NF-B Activation in Human Lens Epithelial Cells Partially via Inhibiting the Ubiquitin-Proteasome Pathway
Author Affiliations & Notes
  • M. Wu
    Department of Cataract, Zhongshan Ophthalmic Center, Guangzhou, China
  • Q. Bian
    Department of Cataract, Zhongshan Ophthalmic Center, Guangzhou, China
    Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
  • A. F. Fernandes
    Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
    Center of Ophthalmology, University of Coimbra, Coimbra, Portugal
  • A. Taylor
    Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
  • P. Pereira
    Center of Ophthalmology, University of Coimbra, Coimbra, Portugal
  • F. Shang
    Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
  • Footnotes
    Commercial Relationships  M. Wu, None; Q. Bian, None; A.F. Fernandes, None; A. Taylor, None; P. Pereira, None; F. Shang, None.
  • Footnotes
    Support  CNSF grant 30572002; NIH grant EY11717; USDA CRIS 1950-51000-060-01A; POCI/SAU-OBS/57772/2004
Investigative Ophthalmology & Visual Science May 2008, Vol.49, 2277. doi:https://doi.org/
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      M. Wu, Q. Bian, A. F. Fernandes, A. Taylor, P. Pereira, F. Shang; Chronic Oxidative Stress Inhibits NF-B Activation in Human Lens Epithelial Cells Partially via Inhibiting the Ubiquitin-Proteasome Pathway. Invest. Ophthalmol. Vis. Sci. 2008;49(13):2277. doi: https://doi.org/.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose: : NF-ΚB is important transcription factor for cell survival, proliferation and transformation. Previous work indicates that transient oxidative stress activates NF-ΚB in lens epithelial cells. The objective of this study is to determine the effect of chronic oxidative stress on signaling events of TNFα-induced NF-ΚB activation and the underlying mechanism.

Methods: : HLEC (SRA 01/04) were exposed to a continuous flux of hydrogen peroxide produced by glucose and glucose oxidase for 4 hours. TNFα was then added to trigger the activation of NF-ΚB. DNA binding activity of NF-ΚB was determined using electrophoretic mobility shift assay (EMSA). Phosphorylation and degradation of the inhibitor of NF-ΚB (I-ΚB) were determined by Western blotting. Proteasome activity was determined using fluorogenic peptides as substrates.

Results: : Unlike transient oxidative stress, chronic exposure of HLEC to physiologically relevant levels of H2O2 (50 µM for 4 hours) did not induce the degradation of I-ΚB and activation of NF-ΚB. However, chronic exposure to H2O2 attenuated TNFα-induced degradation of I-ΚB and activation of NF-ΚB. Chronic exposure of HLEC to these levels of H2O2 also inhibited proteasome activity by 40-50%. Consistent with the role of the ubiquitin-proteasome pathway (UPP) in degradation of I-ΚB and activation of NF-ΚB, treatment of HLEC with proteasome inhibitors also attenuated TNFα-induced degradation of I-ΚB and activation of NF-ΚB.

Keywords: oxidation/oxidative or free radical damage • signal transduction • proteolysis 
×
×

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.

×