title: Expression of Lymphangiogenic Markers in Rejected Human Corneal Buttons after Penetrating Keratoplasty.
abstract: OBJECTIVE
  To investigate the extent and distribution of lymphangiogenesis in the rejected corneal graft, we determined the expression of several lymphangiogenic markers in rejected human corneal buttons.
  
  
  METHODS
  Thirty-four corneal buttons were obtained from patients who underwent re-keratoplasty for graft rejection after penetrating keratoplasty. All corneas showed signs of rejection, such as, sudden mutton-fat keratic precipitates (KPs) or lines before re-keratoplasty. The corneas were halved, and one half was used for immunostaining and the other half was used for RT-PCR. Expression of vascular endothelial growth factor (VEGF)-A, VEGF-C, VEGF-D, VEGFR-2, VEGFR-3, LYVE-1 and podoplanin were measured as lymphangiogenic markers. Four non-operated normal corneas were used as controls.
  
  
  RESULTS
  Numerous podoplanin positive cells were found in the anterior and posterior stroma. However, LYVE-1 positive mature lymphatics were found only in herpetic keratitis (HK)-induced graft rejection, and not in pseudophakic bullous keratopathy (PBK). RT-PCR showed that levels of VEGF-A, VEGF-C, VEGFR-2, and VEGFR-3 mRNAs were elevated in rejected corneal buttons versus the non-operated control corneas. Based upon the pre-keratoplasty pathologic conditions, HK cases showed higher levels of VEGF-A and VEGFR-2 than PBK. The mRNA ratios (keratoplastic cornea/normal cornea) for VEGF-A and VEGFR-2 were 8.9 and 5.8, respectively.
  
  
  CONCLUSIONS
  The results suggested that the VEGF-A and the VEGFR-2 may be a more important pathway for lymphangiogenesis in rejected corneal grafts than the VEGFR-3. In addition, organized lymphangiogenesis is more prominent in HK than PBK.
authors.affiliation: Department of Ophthalmology, Institute of Vision Research, Yonsei University College of Medicine , Seoul , Korea .
authors.forename: Yuri
authors.initials: Y
authors.lastname: Seo
authors.forename: Mee Kum
authors.initials: MK
authors.lastname: Kim
authors.forename: Joon H
authors.initials: JH
authors.lastname: Lee
authors.forename: Eun-Ju
authors.initials: EJ
authors.lastname: Chang
authors.forename: Eung Kweon
authors.initials: EK
authors.lastname: Kim
authors.forename: Hyung Keun
authors.initials: HK
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D003315:Cornea / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation; D006084:Graft Rejection / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D015948:Keratoplasty, Penetrating / Q000009:adverse effects*; D042583:Lymphangiogenesis / Q000235:genetics*; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D012313:RNA / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D042442:Vascular Endothelial Growth Factors / Q000096:biosynthesis / Q000235:genetics*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D042442:Vascular Endothelial Growth Factors; D012313:RNA
keywords: Lymphangiogenesis; VEGF; VEGFR; penetrating keratoplasty; rejection