Recombinant TIGR/MYOC increases outflow resistance in the human anterior segment

Invest Ophthalmol Vis Sci. 2000 Dec;41(13):4163-8.


Purpose: To determine the effect of human recombinant TIGR/myocilin (MYOC) protein on outflow resistance in the human anterior segment.

Methods: A cDNA for MYOC was inserted into a bacterial expression system and purified with nickel ion affinity chromatography. The anterior segments of 12 pairs of human eyes were placed in perfusion organ culture. One eye received an anterior chamber exchange with partially purified recombinant MYOC (25 microgram), whereas the other eye received either heat-denatured recombinant MYOC (25 microgram), partially purified ss-galactosidase (25 or 250 microgram), or partially purified control proteins isolated from a null expression lysate (25 microgram). Eyes were fixed up to 72 hours after infusion, and immunohistochemistry was performed using anti-MYOC polyclonal antibody.

Results: Recombinant MYOC caused an increase in IOP over 12 hours, increasing outflow resistance 94%, whereas the fellow eye infused with null expression sample increased 12% (n = 7; P = 0.0005). When compared with recombinant MYOC, neither heat-denatured MYOC, recombinant ss-galactosidase, bovine serum albumin, nor fetal calf serum caused an increase in outflow resistance. MYOC IOP remained above baseline levels for 48 to 72 hours. Immunohistochemistry results confirmed the presence of recombinant MYOC in the trabecular meshwork.

Conclusions: Recombinant MYOC increased outflow resistance in human anterior segments, whereas control proteins did not. MYOC may increase outflow resistance by specific interactions within the trabecular meshwork.

Publication types

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

MeSH terms

  • Aged
  • Aged, 80 and over
  • Anterior Eye Segment / drug effects*
  • Anterior Eye Segment / metabolism
  • Aqueous Humor / metabolism*
  • Blotting, Western
  • Chromatography, Affinity
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / isolation & purification
  • Cytoskeletal Proteins / pharmacology*
  • Electrophoresis, Polyacrylamide Gel
  • Eye Proteins / genetics
  • Eye Proteins / isolation & purification
  • Eye Proteins / pharmacology*
  • Fluorescent Antibody Technique, Indirect
  • Gene Expression
  • Glycoproteins / genetics
  • Glycoproteins / isolation & purification
  • Glycoproteins / pharmacology*
  • Humans
  • Intraocular Pressure / drug effects*
  • Middle Aged
  • Organ Culture Techniques
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / pharmacology
  • Trabecular Meshwork / drug effects
  • Trabecular Meshwork / metabolism
  • Transfection


  • Cytoskeletal Proteins
  • Eye Proteins
  • Glycoproteins
  • Recombinant Proteins
  • trabecular meshwork-induced glucocorticoid response protein