May 2003
Volume 44, Issue 13
Free
ARVO Annual Meeting Abstract  |   May 2003
Interaction of Lumican with Aggrecan in the Aging Human Sclera
Author Affiliations & Notes
  • J.R. Dunlevy
    Anatomy & Cell Biology, UND School of Medicine, Grand Forks, ND, United States
  • J.A. Rada
    Anatomy & Cell Biology, UND School of Medicine, Grand Forks, ND, United States
  • Footnotes
    Commercial Relationships  J.R. Dunlevy, None; J.A. Rada, None.
  • Footnotes
    Support  NIH #EYO9391 (JAR)
Investigative Ophthalmology & Visual Science May 2003, Vol.44, 413. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      J.R. Dunlevy, J.A. Rada; Interaction of Lumican with Aggrecan in the Aging Human Sclera . Invest. Ophthalmol. Vis. Sci. 2003;44(13):413.

      Download citation file:


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

      ×
  • Supplements
Abstract

Abstract: : Purpose:To characterize changes in the scleral extracellular matrix with increasing age, the lumican (keratan sulfate proteoglycan) core protein was examined in different regions of the human sclera from donors aged 6 – 89 years. Methods: Lumican was immunoaffinity purified from 4 M guanidine-HCL extracts of human sclera using antisera specific for a c-terminal region of human lumican (generously supplied by Dr. Peter J. Roughley, Shriner’s Hospitals for Children, Montreal, Canada), and characterized by western blot analysis with and without prior digestion with chondroitinase ABC, keratanase I, II, and/or endo-B-galactosidase. Additionally, lumican was characterized in scleral extracts of human donors 6 – 89 years old. The presence of aggrecan was evaluated in purified lumican fractions and in scleral extracts by western blotting with antisera specific for regions of the human aggrecan core protein (Robin Poole, and John Sandy). Results:Lumican was present in the human sclera as an ~66 kDa core protein with short low or unsulfated keratan sulfate side chains. Additionally, a larger >200 kDa species was apparent on western blots that was immunologically related to lumican. This high molecular weight material increased in amount in scleral extracts with increasing age of the donor. This high molecular weight complex was most abundant in unreduced samples, and about 2/3rds of the ~66 kDa lumican core protein could be released from the complex upon reduction of the scleral extract with 0.49 M DTT. Further characterization of the >200 kDa lumican-immunopurified complex indicated that aggrecan (the cartilage proteoglycan) was covalently associated with lumican. Conclusions:Reducible and nonreducible lumican-aggrecan interactions occur in the scleral extracellular matrix and result in the formation of high molecular weight complexes that increase with age. These results represent the first report showing lumican-aggrecan interactions, and suggest they may play a role in age-related scleral extracellular matrix changes.

Keywords: extracellular matrix • sclera • protein structure/function 
×
×

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.

×