title: Unoprostone isopropyl rescues retinal progenitor cells from apoptosis in vitro.
abstract: OBJECTIVE
  Unoprostone isopropyl is an ocular hypotensive that was originally produced as a prostaglandin F2alpha analogue and is eventually recognized as a synthetic docosanoid. The compound is recently suggested to have potent neuroprotective ability in the retina. The purpose of this study is to test whether and how the biologically active metabolites of unoprostone isopropyl rescue retinal neuro-glial progenitor cells from apoptosis.
  
  
  METHODS
  R28 cells were deprived of serum for 24 hr with or without varying concentrations of unoprostone metabolite M1 or M2 or vehicle in the presence or absence of specific inhibitors against several types of signal transduction proteins. Immunocytochemistry against activated caspase-3 with Hoechst nuclear staining was performed.
  
  
  RESULTS
  Up to 15%of R28 cells became pyknotic and activated caspase-3 immunoreactive after 24-hr serum withdrawal. M1, but not M2, significantly reduced apoptotic cells in a dose-dependent fashion with a maximal effect at 100 microM (p < .0001). LY294002, the phosphatidylinositol 3-OH kinase (PI3K) inhibitor, and KT5823, the protein kinase G (PKG) inhibitor, reversed the antiapoptotic effect of M1.
  
  
  CONCLUSIONS
  The unoprostone metabolite M1 protects retinal neuro-glial progenitor R28 cells from apoptosis induced by serum deprivation via the PI3K and PKG pathways.
authors.affiliation: Department of Organ Therapeutics, Division of Ophthalmology, Kobe University Graduate School of Medicine, Chuo-Ku, Kobe, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Mukuno
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakamura
authors.forename: Akiyasu
authors.initials: A
authors.lastname: Kanamori
authors.forename: Azusa
authors.initials: A
authors.lastname: Nagai
authors.forename: Akira
authors.initials: A
authors.lastname: Negi
authors.forename: Gail
authors.initials: G
authors.lastname: Seigel
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002227:Carbazoles / Q000494:pharmacology; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002867:Chromones / Q000494:pharmacology; D017869:Cyclic GMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D019610:Cytoprotection / Q000187:drug effects; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019084:Fluorescent Antibody Technique, Indirect; D007211:Indoles / Q000494:pharmacology; D009025:Morpholines / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051381:Rats; D012160:Retina / Q000166:cytology* / Q000201:enzymology; D013234:Stem Cells / Q000166:cytology* / Q000201:enzymology
chemical_list: D002227:Carbazoles; D053148:Caspase 3; D020169:Caspases; D002867:Chromones; D017869:Cyclic GMP-Dependent Protein Kinases; D015237:Dinoprost; D004791:Enzyme Inhibitors; D007211:Indoles; D009025:Morpholines; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; C073601:KT 5823; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C072630:isopropyl unoprostone; C505410:Casp3 protein, rat