PURPOSE: The goal of this study was to characterize the morphology of the mucinous layer on rabbit, bovine, owl, and human corneal endothelial cells. METHODS: Corneoscleral buttons were fixed using cetylpyridinium chloride to stabilize "mucus" and the tissue was prepared for transmission electron microscopy. Photomicrographs were measured to determine the thickness of the endothelial and epithelial mucinous layer in the central cornea. RESULTS: The endothelial mucinous layer was seen as a nearly uniform electrodense region on the apical aspect of the endothelium. It was found to be 0.9 microm, 0.9 microm, 0.9 microm, and 0.5 microm thick in rabbit, bovine, owl, and human, respectively. The owl endothelium had an additional less electrodense layer with a granular appearance and a thickness of about 200 microm. The mucinous layer on the epithelium was similar in appearance to that on the endothelium and across species. CONCLUSIONS: The morphologic similarity of the endothelial and epithelial mucinous layers is a serendipitous finding that should prove valuable in experimental design. Ultimately, it is hoped that studies of the posterior corneal surface will deepen our knowledge of endothelial protection.
Adult ; Animal ; Cytokines/pharmacology ; Endothelium, Corneal/ultrastructure ; Endothelium, Corneal/metabolism* ; Endothelium, Corneal/cytology ; Human ; Microscopy, Electron ; Mucins/ultrastructure ; Mucins/metabolism* ; Owls ; Rabbits ; Staining and Labeling

Normally the cornea has a water content varying between 76-78%, a state of relative dehydration maintained through its own metabolism by the active transport of water and ions across its limiting membrane, the epithelium and endothelium. If the metabolism is grossly disturbed or if the effectivity of the limiting membrane is impaired, the living cornea will swell by the absorption of the fluid. Corneal edema are developed due to trauma, inflammation, glaucoma, degeneration, and neuropathic and metabolic conditions. Essential corneal edema are encountered for which no cause can be found, the condition apparantly occuring without other ocular pathology. A 29 years old Korean lady has been found to have bilateral essential edema of the cornea.
Absorption ; Adult ; Biological Transport, Active ; Cornea ; Corneal Edema* ; Dehydration ; Edema ; Endothelium ; Epithelium ; Glaucoma ; Humans ; Inflammation ; Ions ; Membranes ; Metabolism ; Pathology ; Water

The healing mechanism of corneal endothelium after alkali burn was not completely understood. Rabbit cornea was burned with 1N sodium hydxoside for 1 minute. Endothelial F-actin was stained with NBD-phallacidin in regular sequence to find out the details of endothelial healing after alkali burn. F-actin was completely destroyed leaving a sharp margin against the unaffected area 1 hour after the burn. In the 3, 5 and 7 day specimens, highly active F-actin reactions were noted at the wound margin. New multiple F-actin layers, arising from the intact endothelium near the wound margin, were noted in the 9 day specimen. In the 8 1/2 month specimen, the endothelial defected area was covered by large primitive cells, each of which showed F-actin fiber bundles in the cytoplasm with a large nuclear shadow. Nearly all of the large primitive cells showed F-actin fibers arranged in shapes of cell junctions. Twelve months after the burn, endothelial defects were not found. Nearly all of the endothelial cells were normal in size and shape except for some mushroom-like projections toward the anterior chamber in some areas. Nineteen months after the burn, the endothelial cells were normal. Endothelial wound healing process can be continued even 1 year after the alkali burn in rabbit cornea.
Actins/*metabolism ; Animal ; Burns, Chemical/*metabolism ; Endothelium, Corneal/injuries/*metabolis ; Eye Burns/chemically induced/*metabolism ; Female ; Male ; Rabbits ; Sodium Hydroxide/*adverse effects ; Support, Non-U.S. Gov't ; Wound Healing

Primary and secondary corneal endothelial decompensation leads to stromal edema, corneal opacity and loss of visual acuity. The pathogenesis of corneal endothelial decompensation is that adult corneal endothelium in vivo lacks of a robust proliferative response to injury, does not divide sufficiently to replace the lost cells. Previous studies indicate that cell-cell contact inhibition and transforming growth factor-beta2 (TGF-β2) in aqueous humor may be responsible for maintaining human endothelial cells in a non-replicative state in vivo. The results of the experimental investigation by using immunofluorescent staining of the cell cycle-associated proteins and cell proliferation marker Ki67 in corneal endothelium indicate that human corneal endothelial cells in vivo are arrested in the G1-phase and have not exited from the cell cycle. Successful outgrowth in culture of human corneal endothelial cells in vitro and the establishment of the immortalized human endothelial cell line, provide strong evidence that corneal endothelial cells retain proliferative capacity. Experiments with cell culture ex vivo demonstrate that corneal endothelial cells cultured from young donors grow more robustly than those from older donors, and cells cultured from peripheral area of corneas show greater cell density than central regions. Studies have demonstrated that in vitro human corneal endothelia undergo mitotic changes in response to stimulation of growth promoting agents, such as growth factors, EDTA and extracellular matrix. Identification of corneal endothelial stem cells and isolation and culture of human endothelial precursor cells in vitro will be beneficial for further investigation regarding the mechanism of corneal endothelial regeneration as well as corneal endothelial cells in vitro culture.
Aqueous Humor ; metabolism ; Cell Count ; Cell Culture Techniques ; Cell Cycle ; Cell Proliferation ; Cells, Cultured ; Contact Inhibition ; Endothelium, Corneal ; cytology ; Humans ; Stem Cells ; Transforming Growth Factor beta2 ; metabolism

OBJECTIVETo demonstrate the molecular expression of carbonic anhydrase IV (CA IV) in rabbit corneal endothelium.

METHODSReverse transcriptase polymerase chain reaction (RT-PCR) was performed using cultured and fresh rabbit corneal endothelial total RNA and specific primers for CA IV. The RT-PCR product was subcloned and sequenced. Immunoblotting and indirect immunofluorescence staining were performed to detect protein expression and distribution of CA IV using fresh and cultured rabbit corneal endothelium and rat anti-CA IV polyclonal antibody.

RESULTSRT-PCR screening gave positive bands at the predicted size for CA IV from fresh and cultured rabbit corneal endothelium. Sequencing further confirmed the identity of CA IV in corneal endothelium. Immunoblotting analysis showed a single band at 52 kDa for freshly isolated and cultured endothelial cells. Indirect immunofluorescence staining revealed an apparent positive staining in cultured endothelial cells.

CONCLUSIONCarbonic anhydrase IV is expressed in rabbit corneal endothelium, which could contribute to the transendothelial HCO(3)(-) flux that is necessary to maintain corneal hydration and transparency.

Animals ; Base Sequence ; Bicarbonates ; metabolism ; Carbonic Anhydrase IV ; analysis ; genetics ; Cells, Cultured ; Endothelium, Corneal ; cytology ; enzymology ; Fluorescent Antibody Technique, Indirect ; Molecular Sequence Data ; RNA, Messenger ; analysis ; Rabbits

The goal of this study was to evaluate the function of hyaluronic acid (HA) on the active oxygen release from polymorphonuclear leukocytes (PMNs) and the protective effect of bovine corneal endothelial cells (BCEC) from activated PMNs. We used HA with three different molecular weights (MW 700, 000, 2, 000, 000, and 4, 000, 000) and five different concentrations (0, 0.1, 1, 2, and 3 mg/ml). We evaluated the amount of released superoxide from activated PMNs by using dismutase-inhibitable ferricytochrome C reduction. To compare the property and protective effect of HA with those of other viscoelastic substances, we used the same concentration of methylcellulose. HA suppressed superoxide release from PMNs and protected BCEC from activated PMNs in a dose-dependent, rather than a molecular weight-dependent, manner. The effect of HA reached almost a plateau at concentration above 2 mg/ml. However, methylcellulose, another viscoelastic substance, showed a similar effect. Therefore, it seems that the suppression of superoxide released from PMNs is not a property that is unique to HA, but is a general property of viscoelastic substances. Our results indicate that the action mechanism of HA proceeds not only through cell surface HA-receptor. We think that HA also acts as a physical barrier and/or a scavenger of superoxide.
Animals ; Cattle ; Cell Survival ; Cells, Cultured ; Comparative Study ; Cytochromes c/metabolism ; Cytoprotection ; Dose-Response Relationship, Drug ; Endothelium, Corneal/cytology/*drug effects ; Humans ; Hyaluronic Acid/*pharmacology ; Methylcellulose ; Molecular Weight ; *Neutrophil Activation ; Neutrophils/*drug effects/metabolism ; Superoxides/*metabolism

Porcine to rat corneal xenotransplantation resulted in severe inflammation and rejection of the corneal stroma, whereas an allograft showed mainly endothelial cell-associated rejection. We, therefore, investigated and compared the gene expression between porcine keratocytes and corneal endothelial cells. RNA was isolated from primary cultured porcine or human keratocytes and porcine corneal endothelial cells. Gene expression was comparatively analyzed after normalization with microarray method using Platinum pig 13 K oligo chip (GenoCheck Co., Ltd., Ansan, Korea). Real-time polymerase chain reaction (PCR) was performed for C1R, CCL2, CXCL6, and HLA-A in porcine keratocytes and corneal endothelial cells. As a result, upregulated expression more than 2 folds was observed in 1,162 genes of porcine keratocytes versus porcine endothelial cells. Among the immune-regulatory genes, SEMA3C, CCL2, CXCL6, F3, HLA-A, CD97, IFI30, C1R, and G1P3 were highly expressed in porcine keratocytes, compared to porcine corneal endothelial cells or human keratocytes. When measured by real-time PCR, the expression of C1R, CCL2, and HLA-A was higher in porcine keratocytes compared to that in porcine corneal endothelial cells. In conclusion, the increased expression of C1R, CCL2, and HLA-A genes in porcine keratocytes might be responsible for the stromal rejection observed in a porcine to rat corneal xenotransplantation.
Animals ; Cells, Cultured ; Chemokine CCL2/metabolism ; Complement C1r/metabolism ; Corneal Transplantation/*immunology/pathology ; Endothelium, Corneal/*metabolism/pathology ; *Gene Expression Profiling ; Graft Rejection/*immunology/pathology ; HLA-A Antigens/metabolism ; Humans ; Keratinocytes/*metabolism ; Oligonucleotide Array Sequence Analysis ; Rats ; Reverse Transcriptase Polymerase Chain Reaction ; Swine ; Transplantation, Heterologous ; Up-Regulation

PURPOSE: To establish the immortalized human corneal endothelial cell line (IHCEn) by transducing human papilloma virus (HPV) 16 E6/E7 oncogenes, and to identify their characteristics when cultivated on a lyophilized human amniotic membrane (LAM). METHODS: Primary human corneal endothelial cells (PHCEn) were infected using a retroviral vector with HPV 16 E6/E7, and transformed cells were clonally selected by G418. Growth properties and characteristics of IHCEn were compared with PHCEn by cell counting and RT-PCR of VDAC3, SLC4A4, CLCN3, FGF-1, Col IV, and Na+/K+ ATPase. IHCEn were cultured on LAM. Messenger RNA expressions of VDAC3, CLCN3, and Na+/K+ ATPase, and protein expressions of Na+/K+ ATPase and Col IV in IHCEn cultivated on LAM were investigated by RT-PCR, immunofluorescence, and immunohistochemical staining, respectively. RESULTS: Successful immortalization was confirmed by stable expression of HPV 16 E6/E7 mRNA by RT-PCR, and IHCEn exhibited typical corneal endothelial morphology. Doubling time of IHCEn was 30.15+/-10.96 hrs. Both IHCEn and PHCEn expressed VDAC3, CLCN3, SLC4A4, FGF-1, Col IV, and Na+/K+ ATPase. IHCEn cultivated on LAM showed stronger expression of VDAC3, CLCN4, and Na+/K+ ATPase mRNA than on plastic culture dish. Immunohistochemical staining and immunofluorescence revealed the positive expression of Na+/K+ ATPase and Col IV. CONCLUSIONS: IHCEn were successfully established, and LAM is a good substrate for the culture of human corneal endothelial cells.
Transfection ; Reverse Transcriptase Polymerase Chain Reaction ; Repressor Proteins/genetics/*pharmacology ; RNA, Messenger/genetics ; Protein-Tyrosine Kinases ; Oncogene Proteins, Viral/genetics/*pharmacology ; Immunohistochemistry ; Humans ; Gene Expression Regulation, Viral ; Freeze Drying ; Endothelium, Corneal/*cytology/drug effects/metabolism ; Cell Line, Transformed ; Cell Count ; Amnion

Fabry's disease, angiokeratoma corporis diffusum, is a rare X-linked inborn error of glycosphingolipid metabolism due to the lack of the lysosomal enzyme, alpha-galactosidase A, resulting in a progressive intracellular deposition of neutral glycosphingolipids in various tissues, including the dorsal root ganglia, autonomic nervous system, vascular endothelial, and smooth muscle cells. Clinical manifestations of Fabry's disease result predominantly from the progressive deposition of globotriaocylceramide in the nervous system or vascular endothelium, and are characterized by acro-paresthesia, angiokeratoma, corneal opacity, TIA or stroke, ischemic heart disease, and renal failure. We report a case of a 19-year-old man presenting with a 12-year history of severe distal pain, acroparesthesia, short stature, and delayed puberty. An enzymatic assay disclosed substantially diminished alpha-galactosidase A activity and an electron microscopy of the peripheral nerve showed lipid inclusions which were composed of concentrically laminated, ovoid osmiophilic bodies in the perineural fibroblast and endothelial cells. These findings are typical of Fabry's disease and additional genetic study revealed deletion mutation(TTAG) at the 6th exon of the alpha-galactosidase A gene, which is a novel mutation that had never been reported in literatures. Symptomatic treatment with carbamazepine and clonazepam was tried with a good response.
alpha-Galactosidase ; Angiokeratoma ; Autonomic Nervous System ; Carbamazepine ; Clonazepam ; Corneal Opacity ; Endothelial Cells ; Endothelium, Vascular ; Enzyme Assays ; Exons* ; Fabry Disease* ; Fibroblasts ; Ganglia, Spinal ; Humans ; Metabolism ; Microscopy, Electron ; Myocardial Ischemia ; Myocytes, Smooth Muscle ; Nervous System ; Neutral Glycosphingolipids ; Peripheral Nerves ; Puberty, Delayed ; Renal Insufficiency ; Stroke ; Young Adult