title: Effects of glaucoma on Chrna6 expression in the retina.
abstract: OBJECTIVE
  Recent advances in technology now provide tools capable of tracking genome-wide expression changes occurring in progressive pathological processes. The present experiments were carried out to determine if acetylcholine receptor α 6 subunit (Chrna6) is a reliable retinal ganglion cell (RGC) marker in adult mouse eyes and if Chrna6 expression can be used to track progressive loss of RGCs, such as is observed in the DBA/2J glaucoma model.
  
  
  METHODS
  Data sets derived from the BXD strains were used to extract gene expression signatures for RGCs. Pooled retinas from DBA/2J or C57BL/6J cases at 1-3 months, 12 months, and 16-17 months were prepared for gene-array and RT-PCR analysis. Globes were fixed in paraformaldehyde and sectioned for immunofluorescence with antibodies against Chrna6.
  
  
  RESULTS
  Chrna6 has a cellular expression signature for RGCs with high correlation to Thy1 (r = 0.65), a recognized RGC marker. Immunofluorescence experiments confirm that in the young and adult mouse retina, Chrna6 is preferentially expressed by RGCs. We further show that C3H/HeJ retinas, which lack photoreceptors, also express Chrna6 in the RGC layer. Gene expression array analyses, confirmed by RT-PCR, show progressive loss of Chrna6 expression in retinas of the DBA/2J glaucomatous mouse retinas.
  
  
  CONCLUSIONS
  Quantitative trait locus analysis provides support for Chrna6 as a RGC marker. Chrna6 expression decreases with death of RGCs in glaucomatous DBA/2J mice and after optic nerve crush injury, further supporting Chrna6 as a reliable RGC marker. High expression of RGC Chrna6 in the absence of photoreceptors is suggestive that Chrna6 expression by RGCs is independent of photoreceptor-derived stimuli.
authors.affiliation: Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, FL 33136, USA.
authors.forename: Gustavo C
authors.initials: GC
authors.lastname: Munguba
authors.forename: Eldon E
authors.initials: EE
authors.lastname: Geisert
authors.forename: Robert W
authors.initials: RW
authors.lastname: Williams
authors.forename: Mary L
authors.initials: ML
authors.lastname: Tapia
authors.forename: Daisy K
authors.initials: DK
authors.lastname: Lam
authors.forename: Sanjoy K
authors.initials: SK
authors.lastname: Bhattacharya
authors.forename: Richard K
authors.initials: RK
authors.lastname: Lee
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005786:Gene Expression Regulation; D005901:Glaucoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D012313:RNA / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D011978:Receptors, Nicotinic / Q000096:biosynthesis / Q000235:genetics*; D012160:Retina / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: C470410:CHRNA6 protein, human; D011978:Receptors, Nicotinic; D012313:RNA