title: Decreased pigment epithelium-derived factor and increased vascular endothelial growth factor levels in pterygia.
abstract: OBJECTIVE
  Pterygia are histologically composed of proliferating fibrovascular tissue. This study compared expression levels of an angiogenic inhibitor, pigment epithelium-derived factor (PEDF), in pterygia with those in normal corneal and conjunctival tissues.
  
  
  METHODS
  The normal human conjunctival and corneal tissues were obtained from surgery or from donor eyes without ocular diseases. Pterygia were excised by therapeutic surgery under a microscope. Pigment epithelium-derived factor and vascular endothelial growth factor (VEGF) were measured by Western blot analysis. Their cellular localizations were determined by immunohistochemistry.
  
  
  RESULTS
  Intensive PEDF immunostaining was detected in all the normal corneal and conjunctival samples analyzed, predominantly in the epithelium and endothelium of the cornea and in the epithelium of the limbus and conjunctiva. Under the same immunostaining conditions, pterygial samples showed negative or faint PEDF staining. In contrast, the same pterygial samples all showed intensive VEGF staining, predominantly in the epithelium and in blood vessels. Western blot analysis confirmed that the average PEDF level in pterygia was drastically lower than those in normal corneal and conjunctival tissues, respectively. In contrast, the VEGF level in pterygia was significantly higher than in the normal tissues.
  
  
  CONCLUSIONS
  Pterygia exhibit significantly lower PEDF but higher VEGF levels than those in normal corneas and conjunctivae. The decreased PEDF level in pterygia may play a role in the formation and progression of pterygia.
authors.affiliation: Department of Ophthalmology, The Jinhua Central Hospital, Zhejiang, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Jin
authors.forename: Ming
authors.initials: M
authors.lastname: Guan
authors.forename: Jing
authors.initials: J
authors.lastname: Sima
authors.forename: Guoquan
authors.initials: G
authors.lastname: Gao
authors.forename: Mei
authors.initials: M
authors.lastname: Zhang
authors.forename: Zhuguo
authors.initials: Z
authors.lastname: Liu
authors.forename: James
authors.initials: J
authors.lastname: Fant
authors.forename: Jian-xing
authors.initials: JX
authors.lastname: Ma
mesh_terms: D016022:Case-Control Studies; D016228:Endothelial Growth Factors / Q000378:metabolism*; D005136:Eye Proteins; D006801:Humans; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D008222:Lymphokines / Q000378:metabolism*; D009414:Nerve Growth Factors; D011506:Proteins / Q000378:metabolism*; D011625:Pterygium / Q000378:metabolism*; D015843:Serpins / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D000099174:Pigment Epithelium-Derived Factor
chemical_list: D016228:Endothelial Growth Factors; D005136:Eye Proteins; D036341:Intercellular Signaling Peptides and Proteins; D008222:Lymphokines; D009414:Nerve Growth Factors; D011506:Proteins; D015843:Serpins; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D000099174:Pigment Epithelium-Derived Factor