title: Glutathione S-transferase pi isoform (GSTP1) expression in murine retina increases with developmental maturity.
abstract: OBJECTIVE
  Glutathione S-transferase pi isoform (GSTP1) is an intracellular detoxification enzyme that catalyzes reduction of chemically reactive electrophiles and is a zeaxanthin-binding protein in the human macula. We have previously demonstrated that GSTP1 levels are decreased in human age-related macular degeneration (AMD) retina compared to normal controls (Joshi et al., Invest Ophthalmol Vis Sci, e-abstract, 2009). We also showed that GSTP1 levels parallel survival of human retinal pigment epithelial (RPE) cells exposed to ultraviolet (UV) light, and GSTP1 over-expression protects them against UV light damage (Joshi et al., Invest Ophthalmol Vis Sci, e-abstract, 2010). In the present work, we determined the developmental time course of GSTP1 expression in murine retina and in response to light challenge.
  
  
  METHODS
  Eyes from BALB/c mice at postnatal day 20, 1 month, and 2 months of age were prepared for retinal protein extraction and cryo sectioning, and GSTP1 levels in the retina were analyzed by Western blot and immunohistochemistry (IHC). Another group of BALB/c mice with the same age ranges was exposed to 1000 lx of white fluorescent light for 24 h, and their retinas were analyzed for GSTP1 expression by Western blot and IHC in a similar manner.
  
  
  RESULTS
  GSTP1 levels in the murine retina increased in ascending order from postnatal day 20, 1 month, and 2 months of age. Moreover, GSTP1 expression in murine retina at postnatal day 20, 1 month, and 2 months of age increased in response to brief light exposure compared to age-matched controls under normal condition.
  
  
  CONCLUSIONS
  GSTP1 expression in retina increases with developmental age in mice and accompanies murine retinal maturation. Brief exposure to light induces GSTP1 expression in the murine retina across various developmental ages. GSTP1 induction may be a protective response to light-induced oxidative damage in the murine retina.
authors.affiliation: Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA, LWEN@med.miami.edu.
authors.forename: Wen-Hsiang
authors.initials: WH
authors.lastname: Lee
authors.forename: Pratibha
authors.initials: P
authors.lastname: Joshi
authors.forename: Rong
authors.initials: R
authors.lastname: Wen
mesh_terms: D000367:Age Factors; D000818:Animals; D005609:Free Radicals / Q000378:metabolism; D051549:Glutathione S-Transferase pi / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D018384:Oxidative Stress / Q000502:physiology* / Q000528:radiation effects; D010775:Photic Stimulation / Q000009:adverse effects; D012160:Retina / Q000254:growth & development* / Q000378:metabolism* / Q000528:radiation effects
chemical_list: D005609:Free Radicals; D051549:Glutathione S-Transferase pi; C496557:Gstp1 protein, mouse