title: Endothelin2 Induces Expression of Genes Associated with Reactive Gliosis in Retinal Müller Cells.
abstract: OBJECTIVE
  Photoreceptor degeneration is normally accompanied by reactive gliosis and gene expression changes in Müller (glial) cells. The signaling pathway involved inducing these changes in Müller cells is not known. It has been proposed that endothelin2 (EDN2) released by degenerating photoreceptors might induce gliotic changes in Müller cells. In the present study, we directly tested the hypothesis by determining whether treatment of Müller cell cultures with EDN2 results in upregulation of genes known to be expressed in activated Müller cells in vivo.
  
  
  METHODS
  Experiments were carried using an established rat Müller cell line (rMC-1), and gene expression was assessed by qRT-PCR.
  
  
  RESULTS
  We observed that EDN2 treatment upregulated transcripts for glial fibrillary acidic protein (Gfap), Serpina3n and endothelin receptor B (EdnrB), three genes associated with reactive gliosis in Müller cells. Ciliary neurotrophic factor (CNTF) treatment similarly led to induction of Gfap, Serpina3n and EdnrB transcripts, whereas glutamate treatment had no significant effect.
  
  
  CONCLUSIONS
  The finding supports a role for EDN2 as a signaling agent between photoreceptors and Müller cells.
authors.affiliation: a Department of Ophthalmology , Northwestern University Feinberg School of Medicine , Chicago , IL , USA.
authors.forename: Vijay P
authors.initials: VP
authors.lastname: Sarthy
authors.affiliation: a Department of Ophthalmology , Northwestern University Feinberg School of Medicine , Chicago , IL , USA.
authors.forename: Hari
authors.initials: H
authors.lastname: Sawkar
authors.affiliation: a Department of Ophthalmology , Northwestern University Feinberg School of Medicine , Chicago , IL , USA.
authors.forename: V Joseph
authors.initials: VJ
authors.lastname: Dudley
mesh_terms: D000209:Acute-Phase Proteins / Q000235:genetics*; D000818:Animals; D002460:Cell Line; D019333:Endothelin-2 / Q000494:pharmacology*; D063928:Ependymoglial Cells / Q000187:drug effects* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D005904:Glial Fibrillary Acidic Protein / Q000235:genetics*; D005911:Gliosis / Q000235:genetics*; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D044023:Receptor, Endothelin B / Q000235:genetics*; D015843:Serpins / Q000235:genetics*
chemical_list: D000209:Acute-Phase Proteins; D019333:Endothelin-2; D005904:Glial Fibrillary Acidic Protein; D044023:Receptor, Endothelin B; C403317:Serpina3n protein, rat; D015843:Serpins
keywords: Ciliary neurotrophic factor; endothelin2; gliosis; neuroprotection; photoreceptor loss