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Abstract #12557 Published in IGR 7-3
Existence of heme oxygenase-carbon monoxide-cyclic guanosine monophosphate pathway in human trabecular meshwork cells in vitro
Li T; Zhang H; Liang FChinese Ophthalmic Research 2005; 23: 473-476
OBJECTIVE: To identify the expression of heme oxygenase (HO)-carbon monoxide (CO)-cyclic guanosine monophosphate (cGMP) pathway in the cultured human trabecular meshwork cells (HTMC) in vitro and evaluate the cGMP activation by hemin. METHODS: HTMC of the third to fourth generation were used in the study. 0.1, 1, 10 and 100 μmol/L of hemin was added in B, E, D, C group separately and equal amount of saline was served as control in the A group for 6 hours. Reverse transcripase - polymerase chain reaction (RT-PCR) was employed for the detection of HO-1 or HO-2 mRNA. Immunohistochemical stain was used to detect HO-1 or HO-2 protein. The relative amounts of carbon monoxide releasing into the media were measured with the quantifying carbon monoxide hemoglobin (HbCO) by spectrophotometry. Radioimmunoassay was used to determine the changes of cGMP in HTMC. RESULTS: Cultured cells had the specific characteristic of HTMC. Genes and proteins of HO-1 and HO-2 were stained as brown immunohistochemically in the cytoplasm of cultured HTMC. The expression level of HO-1 mRNA was 0.941 ± 0.072, 1.383 ± 0.107, 1.875 ± 0.093 and 2.150 ± 0.138 in B, E, D, C group respectively with a statistically significant difference in intergroup and remarkable difference in comparison with the A group (0.702 ± 0.065). The level of HbCO in B, E, D, C group was 0.32 ± 0.02, 0.37 ± 0.02, 0.45 ± 0.03 and 0.54 ± 0.03 respectively, showing a significantly intergroup difference and a statistical difference compared to the A group (0.27 ± 0.02). The level of cGMP in HTMC was 0.582 ± 0.116, 0.817 ± 0.124, 1.364 ± 0.152 and 2.193 ± 0.145 in B, E, D, C group and that of A group was 0.331 ± 0.082 pmol/mg. pro with a significant difference among them. CONCLUSION: Hemin induces the expression of HO-1 mRNA, HbCO and cGMP in a dose-dependent manner. HO-CO-cGMP pathway is existed in the cultured HTMC. Pharmacological stimulation of HO-CO-cGMP pathway may provide a novel therapeutic approach to rescuing glaucoma. LA: Chinese
Dr. T. Li, Department of Ophthalmology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030, China
Classification:
2.5.1 Trabecular meshwork (Part of: 2 Anatomical structures in glaucoma > 2.5 Meshwork)
3.3 Immunohistochemistry (Part of: 3 Laboratory methods)
3.8 Pharmacology (Part of: 3 Laboratory methods)
