Human Amniotic Membrane, Like Corneal Epithelial Basement Membrane, Manifests the α5 Chain of Type IV Collagen

Ken-ichi Endo, Takahiro Nakamura, Satoshi Kawasaki, Shigeru Kinoshita
2004 Investigative Ophthalmology and Visual Science  
PURPOSE. To reexamine whether the ␣5 chain of type IV (␣5 [IV]) collagen, thought to be absent, is in fact present in human amniotic membrane. METHODS. Cryosections of human amniotic membrane obtained at Cesarean section were immunohistochemically examined for the presence of ␣5(IV), with or without inclusion of the denaturing step. Amniotic membrane was digested with collagenase to release the noncollagenous NC1 domain from the ␣-chain. The NC1 domain of ␣5(IV) was then assayed on Western blot
more » ... yed on Western blot analysis. Identical experiments were performed with human corneas and conjunctivae obtained from an American eye bank. RESULTS. The basement membrane of denatured samples of amniotic membrane and cornea stained positive for ␣5(IV). Without the denaturing step, only corneal samples were positive. With or without denaturing, conjunctival epithelium did not stain. Western blot analysis detected NC1 domains of ␣5(IV) in amniotic membrane and corneal samples. CONCLUSIONS. The basement membrane of amniotic membrane resembles that of corneal epithelium but not conjunctiva. Amniotic membrane may be an excellent substrate for corneal epithelial cells. (Invest Ophthalmol Vis Sci.
doi:10.1167/iovs.03-0952 pmid:15161839 fatcat:zv6gdep755a3jgz3xgf5sxywqy