BACKGROUND: The endostatin domain of type XVIII collagen (ColXVIII) inhibits neovascularization and regulates cell migration and matrix turnover. This study was designed to demonstrate the protein and gene expression patterns of ColXVIII/endostatin in the human eye and to ascertain whether endostatin is detectable in ocular fluid samples. METHODS: Twenty human eyes enucleated on account of choroidal melanoma were used for immunohistochemical stainings with antibodies against ColXVIII and endostatin. In situ hybridization was used to localize cells responsible for the production of mRNA for ColXVIII. Tear fluid, aqueous humor, and vitreous gel samples were used for Western immunoblotting to detect endostatin fragments in these samples. RESULTS: ColXVIII was immunolocalized to almost all ocular structures, namely the basement membranes (BMs) of the corneal and conjunctival epithelia, Descement's membrane, the anterior border layer and posterior pigmented epithelium of the iris, the BMs of the pigmented and non-pigmented ciliary epithelia, the internal wall of Schlemm's canal and trabeculae, the ciliary and iris muscle cells, the BMs of the pigment epithelium of the retina, and the internal limiting membrane. Universal expression was seen in the BMs of vascular endothelial cells, and in fibroblasts located in the conjunctiva, the iris, and the ciliary body. Endostatin showed a corresponding pattern, but additional immunostaining was present in the corneal and conjunctival epithelial cells. Most epithelial and mesenchymal cells expressed the mRNA for ColXVIII. Endostatin-containing fragments varying in size were detected in tear fluid, aqueous humor and vitreous gel samples. CONCLUSIONS: Practically all structures of the human eye contain ColXVIII/endostatin, emphasizing its possible important structural and functional role in the human eye. Furthermore, ocular fluid samples contain endostatin fragments, which may contribute to the antiangiogenic properties of the eye.
BACKGROUND: The endostatin domain of type XVIII collagen (ColXVIII) inhibits neovascularization and regulates cell migration and matrix turnover. This study was designed to demonstrate the protein and gene expression patterns of ColXVIII/endostatin in the human eye and to ascertain whether endostatin is detectable in ocular fluid samples. METHODS: Twenty human eyes enucleated on account of choroidal melanoma were used for immunohistochemical stainings with antibodies against ColXVIII and endostatin. In situ hybridization was used to localize cells responsible for the production of mRNA for ColXVIII. Tear fluid, aqueous humor, and vitreous gel samples were used for Western immunoblotting to detect endostatin fragments in these samples. RESULTS: ColXVIII was immunolocalized to almost all ocular structures, namely the basement membranes (BMs) of the corneal and conjunctival epithelia, Descement's membrane, the anterior border layer and posterior pigmented epithelium of the iris, the BMs of the pigmented and non-pigmented ciliary epithelia, the internal wall of Schlemm's canal and trabeculae, the ciliary and iris muscle cells, the BMs of the pigment epithelium of the retina, and the internal limiting membrane. Universal expression was seen in the BMs of vascular endothelial cells, and in fibroblasts located in the conjunctiva, the iris, and the ciliary body. Endostatin showed a corresponding pattern, but additional immunostaining was present in the corneal and conjunctival epithelial cells. Most epithelial and mesenchymal cells expressed the mRNA for ColXVIII. Endostatin-containing fragments varying in size were detected in tear fluid, aqueous humor and vitreous gel samples. CONCLUSIONS: Practically all structures of the human eye contain ColXVIII/endostatin, emphasizing its possible important structural and functional role in the human eye. Furthermore, ocular fluid samples contain endostatin fragments, which may contribute to the antiangiogenic properties of the eye.
Authors: Alberto Auricchio; Kathryn C Behling; Albert M Maguire; Erin M O'Connor; Jean Bennett; James M Wilson; Michael J Tolentino Journal: Mol Ther Date: 2002-10 Impact factor: 11.454
Authors: R Valtola; P Salven; P Heikkilä; J Taipale; H Joensuu; M Rehn; T Pihlajaniemi; H Weich; R deWaal; K Alitalo Journal: Am J Pathol Date: 1999-05 Impact factor: 4.307
Authors: Naomi Fukai; Lauri Eklund; Alexander G Marneros; Suk Paul Oh; Douglas R Keene; Lawrence Tamarkin; Merja Niemelä; Mika Ilves; En Li; Taina Pihlajaniemi; Bjorn R Olsen Journal: EMBO J Date: 2002-04-02 Impact factor: 11.598
Authors: Ritva Ylikärppä; Lauri Eklund; Raija Sormunen; Antti I Kontiola; Aino Utriainen; Marko Määttä; Naomi Fukai; Björn R Olsen; Taina Pihlajaniemi Journal: FASEB J Date: 2003-10-02 Impact factor: 5.191
Authors: Magali M Le Goff; Hongbin Lu; Marta Ugarte; Stephen Henry; Masamine Takanosu; Richard Mayne; Paul N Bishop Journal: Invest Ophthalmol Vis Sci Date: 2012-01-25 Impact factor: 4.799
Authors: Paramananda Saikia; Carla S Medeiros; Shanmugapriya Thangavadivel; Steven E Wilson Journal: Cell Tissue Res Date: 2018-10-03 Impact factor: 5.249
Authors: Magali M Le Goff; Matthew J Sutton; Mark Slevin; Ayse Latif; Martin J Humphries; Paul N Bishop Journal: J Biol Chem Date: 2012-06-05 Impact factor: 5.157
Authors: Saumya S VanderWyst; Kristin M Perkumas; A Thomas Read; Darryl R Overby; W Daniel Stamer Journal: Mol Vis Date: 2011-01-19 Impact factor: 2.367
Authors: Andrew E Pouw; Mark A Greiner; Razek G Coussa; Chunhua Jiao; Ian C Han; Jessica M Skeie; John H Fingert; Robert F Mullins; Elliott H Sohn Journal: Cells Date: 2021-03-20 Impact factor: 7.666