title: The Expression of Bone Morphogenetic Protein 2 and Matrix Metalloproteinase 2 through Retinoic Acid Receptor Beta Induced by All-Trans Retinoic Acid in Cultured ARPE-19 Cells.
abstract: OBJECTIVE
  All-trans retinoic acid (ATRA) plays an important role in ocular development. Previous studies found that retinoic acid could influence the metabolism of scleral remodeling by promoting retinal pigment epithelium (RPE) cells to secrete secondary signaling factors. The purpose of this study was to investigate whether retinoic acid affected secretion of bone morphogenetic protein 2 (BMP-2) and matrix metalloproteinase 2 (MMP-2) and to explore the signaling pathway of retinoic acid in cultured acute retinal pigment epithelial 19 (ARPE-19) cells.
  
  
  METHODS
  The effects of ATRA (concentrations from 10-9 to 10-5 mol/l) on the expression of retinoic acid receptors (RARs) in ARPE-19 cells were examined at the mRNA and protein levels using reverse transcription-polymerase chain reaction (RT-PCR) and western blot assay, respectively. The effects of treating ARPE-19 cells with ATRA concentrations ranging from 10-9 to 10-5 mol/l for 24 h and 48 h or with 10-6mol/l ATRA at different times ranging from 6h to 72h were assessed using real-time quantitative PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA). The contribution of RARβ-induced activation of ARPE-19 cells was confirmed using LE135, an antagonist of RARβ.
  
  
  RESULTS
  RARβ mRNA levels significantly increased in the ARPE-19 cells treated with ATRA for 24h and 48h. These increases in RARβ mRNA levels were dose dependent (at concentrations of 10-9 to 10-5 mol/l) with a maximum effect observed at 10-6 mol/l. There were no significant changes in the mRNA levels of RARα and RARγ. Western blot assay revealed that RARβ protein levels were increased significantly in a time-dependent manner in ARPE-19 cells treated with 10-6 mol/l ATRA from 12 h to 72 h, with a marked increase observed at 24 h and 48 h. The upregulation of RARβ and the ATRA-induced secretion in ARPE-19 cells could be inhibited by the RARβ antagonist LE135.
  
  
  CONCLUSIONS
  ATRA induced upregulation of RARβ in ARPE-19 cells and stimulated these cells to secrete BMP-2 and MMP-2.
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, SunYat-sen University, No.54 South Xianlie Road, Guangzhou, 510060, P. R. China.
authors.forename: Zhenya
authors.initials: Z
authors.lastname: Gao
authors.affiliation: The First Affiliated Hospital, Sun Yat-sen University, No.58 Zhong Shan Er Road, Guangzhou 510080, P. R. China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Huo
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, SunYat-sen University, No.54 South Xianlie Road, Guangzhou, 510060, P. R. China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, SunYat-sen University, No.54 South Xianlie Road, Guangzhou, 510060, P. R. China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, SunYat-sen University, No.54 South Xianlie Road, Guangzhou, 510060, P. R. China.
authors.forename: Junwen
authors.initials: J
authors.lastname: Zeng
mesh_terms: D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003984:Dibenzazepines / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D018168:Receptors, Retinoic Acid / Q000235:genetics / Q000378:metabolism*; D055213:Retinal Pigment Epithelium / Q000166:cytology* / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D014212:Tretinoin / Q000494:pharmacology*; D015854:Up-Regulation
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D003984:Dibenzazepines; C104182:LE 135; D018168:Receptors, Retinoic Acid; C082925:retinoic acid receptor beta; D014212:Tretinoin; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2