title: Immunolocalization of prolyl 4-hydroxylase in fibroblasts cultured from Tenon's capsule of humans.
abstract: BACKGROUND
  The excessive accumulation of extracellular matrix (ECM) with the repopulation of fibroblasts may lead to an unsuccessful outcome of glaucoma filtering surgery. We examined the immunolocalization of ECM components and prolyl 4-hydroxylase, an enzyme involved in collagen biosynthesis, in cultured Tenon's capsule fibroblasts (TCFs) of humans to evaluate the production of ECM in the cells.
  
  
  METHODS
  We used light microscopy to evaluate the immunolocalization of prolyl 4-hydroxylase and ECM components, collagen types I, III, and IV, cellular fibronectin, and laminin in TCFs. Ultrastructural localization of the enzyme was also evaluated by electron microscopy.
  
  
  RESULTS
  Immunoreactivity with monoclonal antibodies against the alpha and beta subunits of the enzyme or with the polyclonal antibody against it was detected in the cytoplasm of the cells in a fine granular pattern, indicating its localization in the endoplasmic reticulum (ER). Immunoreactivity for the enzyme was detected in the cisternae of the ER on electron microscopy. Types I and III collagen reactivities were also observed in the cytoplasm in a fine granular pattern. Type IV collagen reactivity was present diffusely on the cell surface. The distribution of laminin reactivity in the cytoplasm resembled that of types I and III collagen. Cellular fibronectin reactivity was observed in the ECM in a reticular pattern.
  
  
  CONCLUSIONS
  Prolyl 4-hydroxylase was located in the cisternae of the ER. TCFs produced a variety of ECM components in vitro. The results provide insight into the fibrotic process during scar formation at the site of a bleb following filtering surgery.
authors.affiliation: Department of Ophthalmology, Wakayama Medical College, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Saika
authors.forename: A
authors.initials: A
authors.lastname: Ooshima
authors.forename: O
authors.initials: O
authors.lastname: Yamanaka
authors.forename: O
authors.initials: O
authors.lastname: Tonoe
authors.forename: Y
authors.initials: Y
authors.lastname: Okada
authors.forename: Y
authors.initials: Y
authors.lastname: Ohnishi
authors.forename: M
authors.initials: M
authors.lastname: Kimura
mesh_terms: D000368:Aged; D002478:Cells, Cultured; D003094:Collagen / Q000145:classification / Q000378:metabolism; D003238:Connective Tissue / Q000201:enzymology* / Q000378:metabolism; D003239:Connective Tissue Cells; D005109:Extracellular Matrix / Q000378:metabolism; D005123:Eye / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000201:enzymology / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D016253:Microscopy, Immunoelectron; D011393:Procollagen-Proline Dioxygenase / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D003094:Collagen; D011393:Procollagen-Proline Dioxygenase