PURPOSE: To determine the effect of exogenous nitric oxide (NO) on the migration of trabecular meshwork (TM) cells and its association with expression of matrix metalloproteinases (MMPs). METHODS: Primary human TM cells treated with 1 or 10 microM S-nitroso-N-acetyl-penicillamine (SNAP) and examined for changes in adherence. TM cells were seeded onto transwell culture inserts, and changes in their migratory activity were quantified. Reverse transcription polymerase chain reaction was performed to determine the relative changes in mRNA expression of MMPs and tissue inhibitor of metalloproteinases (TIMPs). RESULTS: Treatment with SNAP did not significantly suppress TM cell adhesion or migration (p > 0.05). Treatment of TM cells with 10 microM SNAP decreased expression of MMP-2 and increased expression of membrane type MMP-1 and TIMP-2. Treatment with interleukin-1alpha triggered MMP-3 expression but did not exert significant effects on MMP-3 activation in response to SNAP. CONCLUSIONS: These data suggest that NO revealed no significant effect on the migration of TM cells because NO decreased MMP-2 and increased TIMP-2 expression. Although expression of certain MMPs and TIMPs change in response to NO donors, NO may modulate trabecular outflow by changing the cellular production of extracellular matrix without having a significant effect on the migration of TM cells.
Cell Movement/*drug effects ; Cell Survival/drug effects ; Cells, Cultured ; DNA Primers/chemistry ; Gene Expression Regulation, Enzymologic/*physiology ; Humans ; Matrix Metalloproteinases/*genetics ; Nitric Oxide Donors/*pharmacology ; RNA, Messenger/genetics ; Real-Time Polymerase Chain Reaction ; S-Nitroso-N-Acetylpenicillamine/*pharmacology ; Tissue Inhibitor of Metalloproteinase-2/*genetics ; Trabecular Meshwork/cytology/*drug effects/enzymology

BACKGROUNDTrabecular meshwork (TM) cell volume may be an important determinant of aqueous humor outflow in the eye. This study aimed to evaluate the role of HepII domain peptides V on corneal permeability, corneal endothelial cells, intraocular pressure (IOP) and morphology of trabecular meshwork in rats.

METHODSThe IOP of rat eyes was measured before and 3, 5, 7 and 8 hours after topical delivery of HepII domain peptides V through intracameral injections. The peptide's concentration in aqueous humor was assessed by high performance liquid chromatography (HPLC). The shape and density of endothelial cells were observed by laser confocal microscopy 8 hours, 3 and 14 days after intracameral injections of HepII domain peptides V. The morphological changes in TM of rat eyes were assessed by transmission electron microscopy (TEM).

RESULTSIntracameral injection of HepII domain peptides V significantly (P < 0.001) decreased IOP by (5.71 ± 2.10) mmHg in rats at 5 hours after injection. There were no obvious changes of the shape and the density of corneal endothelial cells. In addition, morphological changes in the TM of rats were observed including the expansion of intercellular spaces in the juxtacanalicular meshwork, removal of extracellular material, cellular relaxation, and cytoskeleton reorganization.

CONCLUSIONSHepII domain peptides V could not penetrate cornea and was safe to corneal endothelial cells. HepII domain peptides V could significantly decrease IOP in rat probably by disorganizing actin cytoskeleton and cell-junction in the TM.

Animals ; Chromatography, High Pressure Liquid ; Cornea ; cytology ; drug effects ; ultrastructure ; Endothelium, Corneal ; drug effects ; ultrastructure ; Female ; Fibronectins ; chemistry ; pharmacology ; Intraocular Pressure ; drug effects ; Male ; Microscopy, Confocal ; Microscopy, Electron, Transmission ; Rats ; Rats, Sprague-Dawley ; Trabecular Meshwork ; drug effects ; ultrastructure

PURPOSE: To investigate the effect of insulin on the production of nitric oxide (NO) in the trabecular meshwork (TM) cells and the enzymatic synthetic pathway of tetrahydrobiopterin (BH4) synthesis. METHODS: Primarily cultured human TM cells were exposed to 1, 10, and 100 microgram/ml of insulin and 0, 1, 10, 100 and 1000 nM dexamethasone for 3 days. To evaluate the enzymatic pathway of BH4 synthesis, 10 micrometer dexamethasone, 5 mM diaminopyrimidinone, 100 micrometer ascorbic acid, 100 micrometer sepiapterin, or 10 micrometer methotrexate were also co-administered respectively. Cellular survival and NO production were measured with MTT and Griess assay. RESULTS: Insulin enhanced NO production in a dose-dependent manner significantly (p<0.05) without affecting cell viability, whereas dexamethasone inhibited NO production. With co-exposure of insulin, diaminopyrimidinone and sepiapterin inhibited insulin-induced NO production. Ascorbic acid increased NO production independent of insulin and methotrexate did not affect to the action of insulin in NO production. CONCLUSIONS: Insulin increases NO production in TM cells via de novo synthetic pathway for BH4 synthesis. Insulin could be involved in the regulation of trabecular outflow by enhancing NO production in TM cells.
Trabecular Meshwork/cytology/*drug effects/*metabolism/physiology ; Nitric Oxide/*biosynthesis ; Insulin/administration & dosage/*pharmacology ; Humans ; Dose-Response Relationship, Drug ; Cells, Cultured ; Cell Survival/drug effects ; Biopterin/*analogs & derivatives/biosynthesis

PURPOSE: This study investigated the role of ascorbic acid on the production of nitric oxide (NO) in the trabecular meshwork (TM) cells. METHODS: After primarily cultured human TM cells were exposed to 1, 10, and 100 micrometer of L-ascorbic acid (LAA), with or without co-administration of 1 mM sodium nitroprusside or 100 micrometer hydrogen peroxide for 48 hr, cellular survival and NO production were measured with MTT and Griess assay, respectively. RESULTS: LAA significantly potentiated NO production in a dose-dependent manner (p< 0.05) without affecting cell viability. LAA increased cell viability after hydrogen peroxide-induced oxidative stress in a dose-dependent manner. LAA enhanced NO production in TM cells and showed a cytoprotective effect against hydrogen peroxide-induced oxidative stress. CONCLUSIONS: LAA might be involved in the regulation of trabecular outflow by enhancing NO production in TM cells.
Trabecular Meshwork/cytology/*drug effects/*metabolism ; Nitric Oxide/*biosynthesis ; Humans ; Dose-Response Relationship, Drug ; Cells, Cultured ; Cell Survival/drug effects ; Ascorbic Acid/administration & dosage/*pharmacology

Cells, Cultured ; Claudin-1 ; Dexamethasone ; pharmacology ; Electric Impedance ; Gene Expression Regulation ; drug effects ; Glaucoma ; chemically induced ; Humans ; Membrane Proteins ; genetics ; Trabecular Meshwork ; cytology ; drug effects ; metabolism

To evaluate the effect of dexamethasone on the expression of aquaporin-1 (AQP-1) in cultured bovine trabecular meshwork cells, bovine trabecular meshwork cells were cultured in vitro and reproduced to the third and the fourth generation, then treated with dexamethasone at the concentrations of 5, 25, 50, 250 microg/L respectively for 7 days. Immunohistochemical technique-supervision method was employed to measure, and image analysis system to analyze the expression of AQP-1 in normal cultured bovine trabecular meshwork cells and those treated with dexamethasone. In normal bovine trabecular meshwork cells, the grayscale of AQP-1 positive staining was 167.94 +/- 1.18, while it was 168.92 +/- 0.91, 176.72 +/- 1.80, 180.64 +/- 1.31, 185.64 +/- 1.58 in cells treated with 5, 25, 50, 250 microg/L concentrations of dexamethasone. When the concentration of dexamethasone was higher than 25 microg/L, the expression of AQP-1 was significantly inhibited (P < 0.05). The regulation of AQP-1 expression by dexamethasone in cultured bovine trabecular meshwork cells in vitro may be one of causes that retard the aqueous outflow in glucocorticoid- induced glaucoma.
Aquaporin 1/*biosynthesis ; Aquaporin 1/genetics ; Cells, Cultured ; Depression, Chemical ; Dexamethasone/*pharmacology ; Dose-Response Relationship, Drug ; Immunohistochemistry ; Trabecular Meshwork/cytology ; Trabecular Meshwork/*metabolism

To study the effect of tTG fully phosphorothioated antisense oligodeoxynucleotides (tTG-ASDON) on tTG expression in cultured bovine trabecular meshwork cells (BTMCs) in vitro and explore a new treatment alternative for primary open angle glaucoma (POAG), the ASDON1 and ASDON2 complementary to the protein codogram region of tTG were designed, synthesized and phosphorothioated according to the secondary structure of tTG. The ASDON1 and ASDON2 were embedded in Lipofectamine and transfected into BTMCs. The untreated group served as negative controls. The expression of tTG in the mRNA and protein level were measured by semi-quantitative RT-PCR and immunohistochemical technique-Supervision method respectively. Our results showed that both the mRNA and the protein of tTG with tTG-ASDON and tTG-ASDON2 were significantly decreased as compared with that of the controls (P < 0.05). On the other hand, no significant difference was found between the ASDON1 group and the ASDON2 group. It is concluded that the expression of tTG mRNA and protein in cultured BTMC are down-regulated by tTG- ASDON. As a result, tTG-ASDON may be used for the treatment of POAG through the inhibitory effect on the expression of tTG.
Cells, Cultured ; Glaucoma, Open-Angle/metabolism ; Oligonucleotides, Antisense/*pharmacology ; RNA, Messenger/biosynthesis ; RNA, Messenger/genetics ; Trabecular Meshwork/cytology ; Trabecular Meshwork/*metabolism ; Transglutaminases/*biosynthesis ; Transglutaminases/genetics ; Transglutaminases/*pharmacology

Whether tranilast had antagonistic effect on proliferation inhibition and collagen synthesis promotion induced by TGF-beta2 in cultured human trabecular meshwork cells was investigated. Suspension of 1 x 10(4) cultured human trabecular meshwork cells of 3-5 passage was distributed in each well of a 96-well disk and divided into control group and experimental group. After 24 h, 0 microg/ml (control), 12.5 microg/ml, 25 microg/ml, 50 microg/ml tranilast with 3.2 ng/ml TGF-beta2 were added into the incubation medium. Another 24 h later, proliferation and collagen synthesis in cultured human trabecular meshwork cells were examined respectively by using tetrazolium-based semiautomated colormetric (MTT) assay and 3H-proline incorporation with liquid scintillation technique. The results showed absorbance (A) values of the experimental groups were 0.9036 +/- 0.3017, 1.1361 +/-0.1352, 1.2457 +/- 0.1524 according to the different concentrations of tranilast, and 0.8956 +/-0.1903 of the control group. In comparison with the control group, 25 microg/ml (q'= 3.23, P< 0.05), 50 microg/ml (q'=4.70, P<0.01) tranilast significantly antagonized the decrease of the A values induced by TGF-beta2 in the cultured human trabecular meshwork cells. In comparison with the control group [817.37+/-124.21 cpm/10(4) cells], 12.5 microg/ml (620.33+/-80.46 cpm/10(4) cells, q'= 4.26, P<0.05), 25 microg/ml (594.58+/-88.13 cpm/10(4) cells, q'=4.81, P<0.01), 50 microg/ml (418.64+/-67.90 cpm/10(4) cells, q'=8.62, P<0.01) tranilast significantly inhibited the incorporation of 3H-proline into the cultured human trabecular meshwork cells promoted by TGF-beta2 in a dose-dependent manner. It was concluded that tranilast had the antagonistic effect on the proliferation inhibition and collagen synthesis promotion induced by TGF-alpha2 in the cultured human trabecular meshwork cells.
Cell Proliferation ; drug effects ; Cells, Cultured ; Collagen ; biosynthesis ; Humans ; Trabecular Meshwork ; cytology ; metabolism ; Transforming Growth Factor beta ; antagonists & inhibitors ; Transforming Growth Factor beta2 ; ortho-Aminobenzoates ; pharmacology

The effects of suppression of CD44 by CD44-specific antisense oligonucleotide on attachment of human trabecular meshwork cells to hyaluronic acid (HA) were observed and the possible relationship between CD44 and primary open-angle glaucoma (POAG) investigated. CD44-specific antisense oligonucleotide was delivered with cationic lipid to cultured human trabecular meshwork cells. The expression of CD44 suppressed by CD44-specific antisense oligonucleotide was detected by RT-PCR and Western blotting. The effect of CD44 suppression by specific antisense oligonucleotide on attachment of trabecular meshwork cells to HA was measured by MTT assay. Results showed that expression of CD44 was suppressed by CD44-specific antisense oligonucleotide. Antisense oligonucleotide also suppressed the adhesion of human trabecular meshwork cells to HA in a concentration dependent manner. It was concluded that attachment of human trabecular meshwork cells to HA was decreased when CD44 was suppressed by specific antisense oligonucleotide. CD44 might play a role in pathogenesis of POAG by affecting the adhesion of trabecular meshwork cells to HA.
Cell Adhesion ; Cells, Cultured ; Glaucoma, Open-Angle ; metabolism ; pathology ; Humans ; Hyaluronan Receptors ; biosynthesis ; genetics ; Hyaluronic Acid ; metabolism ; Oligonucleotides, Antisense ; pharmacology ; Trabecular Meshwork ; cytology

To explore the biological effects of light on trabecular cells, cultured bovine trabecular cells were exposed to visible light of different wavelength with different energy. Cellular morphology, structure, proliferation, and phagocytosis were observed. The cells showed no remarkable changes when the energy was low. When the exposure energy reached 1.12 mW/cm2, the cytoplasm showed a rough appearance, and cell proliferation and phagocytosis decreased. This phototoxicity was strong with white light (compound chromatic light), moderate with violet light or yellow light, and mild with red light.
Animals ; Cattle ; Cell Proliferation ; radiation effects ; Cells, Cultured ; Light ; Phagocytosis ; radiation effects ; Trabecular Meshwork ; cytology ; radiation effects