Effect of high glucose on fibronectin expression and cell proliferation in trabecular meshwork cells

Invest Ophthalmol Vis Sci. 2002 Jan;43(1):170-5.


Purpose: Increased fibronectin accumulation in the trabecular meshwork of glaucomatous eyes may contribute to the resistance of aqueous outflow and the development of primary open-angle glaucoma (POAG). Because the glucose level is increased in the aqueous humor of patients with diabetes, this study was conducted to determine whether a high-glucose condition alters fibronectin expression and contributes to cell loss in trabecular meshwork.

Methods: The fibronectin mRNA level was determined using RT-PCR in bovine trabecular meshwork cells grown in normal (5 mM) or high (30 mM)-glucose medium for 7 days, and cell counts were measured during this period. Distribution and the relative amount of fibronectin protein were determined in these cells by immunofluorescence microscopy and Western blot analysis.

Results: Fibronectin mRNA level in cells grown in high-glucose medium was significantly upregulated two- to threefold compared with cells grown in normal medium (P < 0.05). In cells grown in high-glucose medium, fibronectin immunofluorescence was more intense, and the relative amount of fibronectin protein was significantly increased (131% +/- 15% of control, P < 0.05) compared with the amount in cells grown in normal medium. A moderate decrease in cell number was observed in cells grown in high-glucose medium (78% +/- 7% of control, P < 0.05)

Conclusions: These findings indicate that a high glucose level in aqueous humor of patients with diabetes may increase fibronectin syntheses and accumulation in trabecular meshwork and accelerate the depletion of trabecular meshwork cells, a characteristic feature of the outflow system in POAG. The striking similarity between high glucose-induced alterations in trabecular meshwork cells and those of vascular endothelial cells may represent a common biochemical link in the pathogenesis of POAG and diabetic microangiopathy.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Blotting, Western
  • Cattle
  • Cell Count
  • Cell Division / drug effects
  • Cells, Cultured
  • Fibronectins / genetics
  • Fibronectins / metabolism*
  • Glucose / pharmacology*
  • Microscopy, Fluorescence
  • RNA, Messenger / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Trabecular Meshwork / cytology
  • Trabecular Meshwork / drug effects*
  • Trabecular Meshwork / metabolism
  • Up-Regulation


  • Fibronectins
  • RNA, Messenger
  • Glucose