Genipin suppresses subconjunctival fibroblast migration, proliferation and myofibroblast transdifferentiation.
OBJECTIVE
Inchin-ko-to is a herbal medicine which has therapeutic effects in ameliorating liver fibrosis or cholestatic liver diseases. Its main bioactive component is genipin, which is an intestinal bacterial metabolite of this medication. Accordingly, we determined whether or not Inchin-ko-to suppresses in a wound healing model subconjunctival fibroblast (SCF) migration proliferation and myofibroblast transdifferentiation since an inhibitory effect could be of value in improving trabeculotomy outcome.


METHODS
Effects of genipin on SCF cell migration were examined subsequent to wounding confluent monolayer cultures. Alamar blue staining evaluated the effects of genipin (0-50 microg/ml) on fibroblast cell proliferation. Immunostaining determined alpha-smooth muscle actin (alphaSMA) expression. Western blotting evaluated (alphaSMA) expression and phospho-Smad2 formation. Real-time RT-PCR evaluated TGFbeta1 and collagen Ialpha2 mRNA expression. Enzyme-immunoassay determined culture medium collagen I content.


RESULTS
Genipin suppressed wound-induced cell migration and proliferation. It also decreased collagen type I TGFbeta1 and alphaSMA mRNA and protein expression. Smad2 signaling was inhibited by genipin in a dose-dependent manner.


CONCLUSIONS
Genipin suppresses injury-induced fibrogenic responses in SCFs. This result suggests that the herbal medicine Inchin-ko-to might have therapeutic value following trabeculotomy.
Kitano
Ai
A
Department of Ophthalmology, Wakayama Medical University, Wakayama, Japan. aikitano@wakayama-med.ac.jp
Saika
Shizuya
S
Yamanaka
Osamu
O
Ikeda
Kazuo
K
Reinach
Peter S
PS
Nakajima
Yuji
Y
Okada
Yuka
Y
Shirai
Kumi
K
Ohnishi
Yoshitaka
Y
D000199:Actins / Q000378:metabolism; D015153:Blotting, Western; D002454:Cell Differentiation / Q000187:drug effects*; D002465:Cell Movement / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D024042:Collagen Type I / Q000235:genetics; D003228:Conjunctiva / Q000166:cytology*; D004365:Drugs, Chinese Herbal / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology*; D006801:Humans; D057889:Iridoid Glycosides; D039823:Iridoids / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051899:Smad2 Protein / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000235:genetics; D014945:Wound Healing / Q000187:drug effects
D000199:Actins; D024042:Collagen Type I; D004365:Drugs, Chinese Herbal; D057889:Iridoid Glycosides; D039823:Iridoids; D012333:RNA, Messenger; C497782:SMAD2 protein, human; D051899:Smad2 Protein; D053773:Transforming Growth Factor beta1; C078038:inchinko-to; C007834:genipin