title: The novel Rho kinase (ROCK) inhibitor K-115: a new candidate drug for neuroprotective treatment in glaucoma.
abstract: OBJECTIVE
  To investigate the effect of K-115, a novel Rho kinase (ROCK) inhibitor, on retinal ganglion cell (RGC) survival in an optic nerve crush (NC) model. Additionally, to determine the details of the mechanism of K-115's neuroprotective effect in vivo and in vitro.
  
  
  METHODS
  ROCK inhibitors, including K-115 and fasudil (1 mg/kg/d), or vehicle were administered orally to C57BL/6 mice. Retinal ganglion cell death was then induced with NC. Retinal ganglion cell survival was evaluated by counting surviving retrogradely labeled cells and measuring RGC marker expression with quantitative real-time polymerase chain reaction (qRT-PCR). Total oxidized lipid levels were assessed with a thiobarbituric acid-reactive substances (TBARS) assay. Reactive oxygen species (ROS) levels were assessed by co-labeling with CellROX and Fluorogold. Expression of the NADPH oxidase (Nox) family of genes was evaluated with qRT-PCR.
  
  
  RESULTS
  The survival of RGCs after NC was increased 34 ± 3% with K-115, a significantly protective effect. Moreover, a similar effect was revealed by the qRT-PCR analysis of Thy-1.2 and Brn3a, RGC markers. Levels of oxidized lipids and ROS also increased with time after NC. NC-induced oxidative stress, including oxidation of lipids and production of ROS, was significantly attenuated by K-115. Furthermore, expression of the Nox gene family, especially Nox1, which is involved in the NC-induced ROS production pathway, was dramatically reduced by K-115.
  
  
  CONCLUSIONS
  The results indicated that oral K-115 administration delayed RGC death. Although K-115 may be mediated through Nox1 downregulation, we found that it did not suppress ROS production directly. Our findings show that K-115 has a potential use in neuroprotective treatment for glaucoma and other neurodegenerative diseases.
authors.affiliation: Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Kazuichi
authors.initials: K
authors.lastname: Maruyama
authors.affiliation: Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Himori
authors.affiliation: Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Kazuko
authors.initials: K
authors.lastname: Omodaka
authors.affiliation: Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yokoyama
authors.affiliation: Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Shiga
authors.affiliation: Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Ryu
authors.initials: R
authors.lastname: Morin
authors.affiliation: Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Nakazawa
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002470:Cell Survival; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation; D005901:Glaucoma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D007546:Isoquinolines / Q000627:therapeutic use*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018384:Oxidative Stress / Q000235:genetics; D012313:RNA / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012165:Retinal Ganglion Cells / Q000378:metabolism / Q000473:pathology*; D013449:Sulfonamides / Q000627:therapeutic use*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D018800:Thy-1 Antigens / Q000096:biosynthesis / Q000235:genetics; D050819:Transcription Factor Brn-3A / Q000096:biosynthesis / Q000235:genetics; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors*
chemical_list: D007546:Isoquinolines; C584679:K-115; C494189:Pou4f1 protein, mouse; D013449:Sulfonamides; D017392:Thiobarbituric Acid Reactive Substances; D018800:Thy-1 Antigens; D050819:Transcription Factor Brn-3A; D012313:RNA; D054460:rho-Associated Kinases
keywords: Nox; ROCK; glaucoma; neuroprotection; oxidative stress; retinal ganglion cell