J Korean Ophthalmol Soc.  2005 Mar;46(3):510-520.

Effect of Tranilast on the Proliferation of Human Corneal Keratocytes in Vitro

• Lee JE
• Han HJ
• Lee JS
• Oum BS

Abstract

PURPOSE
To evaluate the inhibitory effect of tranilast on proliferation of cultured human keratocytes, and to investigate the apoptotic response and the cellular morphologic changes associated with tranilast in vitro. METHODS: Human corneal keratocytes were exposed to tranilast at a concentration of 0.05, 0.1, 0.2, 0.4, 0.8, 1.6, and 3.2 mg/ml for a period of 4, 24, and 48 hours. Evaluations were conducted with MTT-based-calorimetric assay for measuring the metabolic activity, flow cytometric analysis and fluorescent micrograph for assessing the apoptotic response, and inverted phase-contrast micrograph and electron microscopy for observing the morphologic changes. RESULTS: The inhibitory effect of human keratocyte proliferation was found to have a dose and time dependent pattern (p<0.05). In flow cytometry, the maximal apoptotic response developed at 0.8 mg/ml concentration after 4 and 24 hours of exposure time, and apoptotic cells were demonstrated in fluorescent micrograph. At higher concentration of Tratnilast, human corneal keratocytes were more swollen rather than having a spindle shape and being detached from the bottom of the dish. The damaged keratocytes had degenerative and apoptotic changes like the formation of phagolysosomal granule, marginal condensation in the nucleus, and bleb formation of the nuclear membrane. CONCLUSIONS: The apoptotic response of tranilast is concerned with the inhibitory effect of human corneal keratocyte proliferation. Therefore, tranilast shows promise in clinical use for the inhibition of postoperative excimer laser induced corneal opacity or haze with fewer side effects.

Keyword

Apoptosis; Flow cytometry; Human corneal keratocyte; Tranilast

MeSH Terms

Apoptosis
Blister
Corneal Keratocytes*
Corneal Opacity
Flow Cytometry
Humans*
Lasers, Excimer
Microscopy, Electron
Nuclear Envelope