title: Collagen distribution in the human vitreoretinal interface.
abstract: OBJECTIVE
  To evaluate the presence of collagen types I to VII, IX, XI, and XVIII at the posterior pole, the equator and the pre-equatorial area in human donor eyes, since collagens are important macromolecules that contribute to vitreoretinal adhesion at the vitreoretinal interface.
  
  
  METHODS
  Freshly isolated human retinectomy samples from the equator were used for reverse transcription-polymerase chain reaction to detect mRNA of the above-mentioned collagens. In addition, human donor eyes and equatorial retinectomy samples were embedded in paraffin, stained with antibodies against the collagens and evaluated by light microscopy (LM).
  
  
  RESULTS
  Retinectomy samples expressed mRNA of all tested collagen types. By LM, vitreous cortex was positive for collagen types II, V, IX, and XI. In all three regions within the donor eyes and in the retinectomy samples, the internal limiting membrane (ILM) showed types IV, VI, and XVIII; the retinal vasculature was positive for types I to VI and XVIII in most specimens; and the retinal layers showed condensed spots of type VII. In addition, type VII increased in density and in distribution over the retinal layers toward the posterior pole.
  
  
  CONCLUSIONS
  Staining patterns of collagen types I to V, IX, XI, and XVIII confirmed previous observations. Important new findings include the presence of type VI in the ILM and type VII in several layers of the retina. Both collagens can anchor matrix components, and type VI could be involved in vitreoretinal attachment. Furthermore, the presence of collagen mRNA in human retinectomy samples may be an indication of postnatal collagen production by retinal cells.
authors.affiliation: Department of Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. t.l.ponsioen@ohk.umcg.nl
authors.forename: Theodorus L
authors.initials: TL
authors.lastname: Ponsioen
authors.forename: Marja J A
authors.initials: MJ
authors.lastname: van Luyn
authors.forename: Roelofje J
authors.initials: RJ
authors.lastname: van der Worp
authors.forename: Jan C
authors.initials: JC
authors.lastname: van Meurs
authors.forename: Johanna M M
authors.initials: JM
authors.lastname: Hooymans
authors.forename: Leonoor I
authors.initials: LI
authors.lastname: Los
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003094:Collagen / Q000235:genetics* / Q000378:metabolism*; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D012160:Retina / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014822:Vitreous Body / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D003094:Collagen