Tafluprost protects rat retinal ganglion cells from apoptosis in vitro and in vivo.
BACKGROUND
To investigate whether tafluprost, which is a prostaglandin-related compound and an anti-glaucoma drug, has a direct anti-apoptotic effect in cultured retinal ganglion cells (RGCs) and rat RGCs in retinas with optic nerve crush (ONC).


METHODS
RGC-5 cells were induced to undergo apoptosis by a serum deprivation and by exogenous glutamate. The level of cell death with or without tafluprost was monitored by an XTT assay and by immunocytochemistry with activated caspase-3. Changes in intracellular calcium ([Ca(2+)]i) levels were measured with fluo-4 fluorescence. Rat RGCs were degenerated by ONC. After topical instillation of tafluprost for 7 and 14 days, the numbers of retrograde-labeled RGCs were counted. Retinal flatmounts were subjected to terminal dUTP nick end labeling (TUNEL) staining to detect apoptotic cells.


RESULTS
Tafluprost dose-dependently promoted RGC-5 cell viability with an optimum concentration of 3 microM (p = 0.006). Tafluprost significantly reduced caspase-3-positive cells and suppressed [Ca(+2)]i evoked by exogenous glutamate. The cGMP-dependent protein kinase inhibitor and KT-5823 partially blocked the rescue effect of tafluprost (p = 0.002). The survival rate of RGCs significantly increased in eyes treated with tafluprost (p = 0.01), and the prevalence of TUNEL-positive cells was significantly decreased 14 days after ONC (p < 0.001).


CONCLUSIONS
These data suggest that tafluprost has an anti-apoptotic effect in RGCs.
Kanamori
Akiyasu
A
Department of Surgery, Division of Ophthalmology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Japan. kanaaki@med.kobe-u.ac.jp
Naka
Maiko
M
Fukuda
Masahide
M
Nakamura
Makoto
M
Negi
Akira
A
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002227:Carbazoles / Q000494:pharmacology; D053148:Caspase 3 / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D016895:Culture Media, Serum-Free; D017869:Cyclic GMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D018698:Glutamic Acid / Q000494:pharmacology; D066298:In Vitro Techniques; D007322:Instillation, Drug; D007425:Intracellular Membranes / Q000378:metabolism; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D009409:Nerve Crush; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009883:Ophthalmic Solutions; D009900:Optic Nerve; D011460:Prostaglandins F / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D013997:Time Factors
D002121:Calcium Channel Blockers; D002227:Carbazoles; D016895:Culture Media, Serum-Free; D018696:Neuroprotective Agents; D009883:Ophthalmic Solutions; D011460:Prostaglandins F; D047428:Protein Kinase Inhibitors; C073601:KT 5823; C485333:tafluprost; D018698:Glutamic Acid; D017869:Cyclic GMP-Dependent Protein Kinases; D053148:Caspase 3; D002118:Calcium