Effect of norfloxacin and clonidine on human trabecular meshwork cells in vitro

Insulin-like growth factor-I gene cloning and protein expression in bovine trabecular meshwork tissue and cells

Whether cultured bovine trabecular meshwork cells and trabecular tissue ex vivo express insulin-like growth factor-I (IGF-I) messenger RNA (mRNA) and protein was investigated. Total RNA of cultured bovine trabecular meshwork cells as well as trabecular meshwork tissue freshly excised from bovine eyes was extracted, and reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect IGF-I mRNA. RT-PCR product was verified by sequencing. Immunohistochemical stain was used to detect IGF-I protein. The results showed that a single PCR amplified product was obtained, and the sequence was homologous to the known sequence.. IGF-I immunostain was positive in the cytoplasm of trabecular meshwork cells. It was concluded that trabecular meshwork cells produce IGF-I and contribute to the presence of IGF-I in trabecular meshwork microenvironment as well as aqueous humor. Trabecular meshwork cells were affected by IGF-I not only through paracrine, but also autocrine action. Whether abnormal down-regulations in IGF-I production may contribute to the pathogenesis of primary open-angle glaucoma and the possibility of promoting the autocrine action of IGF-I by trabecular meshwork cells to treat the disease is worth further investigation.

A study of toxicity of 5-fluorouracil on bovine trabecular meshwork cells in vitro

In order to explore whether the conventional use of 5-fluorouracil (5-Fu) had any toxic effects on trabecular meshwork cells, bovine trabecular meshwork cells were cultured in vitro and exposed to 5-Fu at different concentrations. The cellular morphology, ultrastructure, mortality and phagocytosis were studied under light microscopy, transmission electron microscopy and methods of Wright's stain. It was found that the toxic effects of 5-Fu on the cells were in a dose-dependent mode. 1 x 10(-1) mg/ml of 5-Fu caused a large part of cells rounded up, while 1 x 10(-2) mg/ml of the drug only a rough appearance of the cell surface. Exposure to 1 x 10(-2) mg/ml of 5-Fu made mitochrone swollen and rough endoplasmic reticulum enlarged, with the cell mortality being 50.5%. The latex microspheres engulfed in cytoplasm in cells receiving 1 x 10(-1) and 1 x 10(-2) mg/ml of 5-Fu were significantly decreased as compared with those in the control group (P < 0.01). It was concluded that the safe concentration of 5-Fu on bovine trabecular meshwork cells was 1 x 10(-2) mg/ml and the conventional dosage of 5-Fu in clinical practice would not cause injury to trabecular meshwork cells.

Effect of transforming growth factor-beta 2 on phagocytosis in cultured bovine trabecular meshwork cells

The effect of transforming growth factor-beta 2 (TGF-beta 2) on phagocytosis in bovine trabecular meshwork cells in vitro was investigated. After the cultured bovine trabecular meshwork cells were treated with 0 ng/ml, 0.32 ng/ml, 1 ng/ml, 3.2 ng/ml TGF-beta 2 for 24 h, latex beads were added into the incubation medium, and the numbers of the latex beads in 20 adjacent cells were counted under a microscope 24 h later, after treatment with Wright's stain. Our results showed that the average numbers of the latex beads in the trabecular meshwork cells treated with TGF-beta 2 of different concentrations were 53.1 +/- 1.7 beads/cell, 56.4 +/- 2.9 beads/cell and 77.9 +/- 6.5 beads/cell respectively, in comparison with 45.5 +/- 3.3 beads/cell of the control group. TGF-beta 2 significantly increased the number of the latex beads phagocytosed by cultured bovine trabecular meshwork cells in a dose-dependent manner. TGF-beta 2 could promote the phagocytosis of bovine trabecular meshwork cells in vitro. It may be involved in the cellularity decrease of the trabecular meshwork in the patients of primary open angle glaucoma through promoting the phagocytosis of trabecular meshwork cells.

Effects of hydrostatic pressure on cultured bovine trabecular meshwork cells

In order to explore the effects of pressure on trabecular meshwork cells, bovine trabecular meshwork cells were cultured in vitro and subjected to different levels of hydrostatic pressure. The cellular morphology, ultrastructure and phagocytosis were studied with inverted phase-contrast microscopy, light microscopy and transmission electron microscopy, etc. It was found that the cells subjected to 2.0 kPa or 2.67 kPa for 48 h had no remarkable difference as compared with the controls in terms of parameters observed. Those under 4.0 kPa for 24 h showed slight changes in structure and a mild decrease in phagocytic function. The damage appeared more severe if the pressure was higher or lasted longer. From the above we conclude that trabecular meshwork cells can only bear pressure below a certain level. They may be destroyed structurally or impaired functionally by pressure over this level.