PMID- 20554624
OWN - NLM
STAT- MEDLINE
DCOM- 20101207
LR  - 20131121
IS  - 1552-5783 (Electronic)
IS  - 0146-0404 (Linking)
VI  - 51
IP  - 11
DP  - 2010 Nov
TI  - GTx-822, an ERbeta-selective agonist, protects retinal pigment epithelium 
      (ARPE-19) from oxidative stress by activating MAPK and PI3-K pathways.
PG  - 5934-42
LID - 10.1167/iovs.10-5630 [doi]
AB  - PURPOSE: The goal of this study was to determine whether an estrogen receptor-beta 
      (ERbeta)-selective agonist (GTx-822; GTx, Inc., Memphis, TN) could prevent hydrogen 
      peroxide (H(2)O(2))-induced oxidative stress in ARPE-19 cells and to elucidate 
      the molecular pathways involved in this protection. METHODS: The selectivity of 
      GTx-822 for ERbeta was determined by receptor-binding assay (RBA) and 
      transactivation assay. Cultured ARPE-19 cells were subjected to oxidative stress 
      with t-butyl hydroxide (t-BH) or hydrogen peroxide (H(2)O(2)) in the presence and 
      absence of GTx-822. Reactive oxygen species (ROS) was measured by using H(2)DCFDA 
      fluorescence. Apoptosis was evaluated by cell death ELISA. Mitochondrial membrane 
      potential was measured with the JC-1 assay. Gene expression and protein 
      expression and activation were quantitated with qRT-PCR and Western blot 
      analysis. Phospho-protein arrays elucidated the activation of protein kinases. 
      RESULTS: The RBA and transactivation assay revealed that GTx-822 is an 
      ERbeta-selective agonist (K(i) = 0.53 nM). GTx-822 prevented oxidative stress in 
      ARPE-19 cells. It preserved mitochondrial function and prevented cellular 
      apoptosis. Pretreatment with GTx-822 increased ERbeta gene and protein expression 
      during oxidative stress. Upregulation of the phase II antioxidant genes GPx-2 and 
      HO-1 was also seen in an ERbeta-dependent mechanism. GTx-822 pretreatment induced 
      phosphorylation of ERK1/2, PI3-K, and Bad. CONCLUSIONS: This is the first report 
      to show that GTx-822, an ERbeta agonist, can protect ARPE-19 cells from the cellular 
      apoptosis induced by oxidative stress. GTx-822 mediated cytoprotection was 
      mediated through induction of both genomic and nongenomic pathways. The results 
      of this study open new avenues for the use of a selective ERbeta agonist in 
      treatment of ocular diseases like AMD where oxidative stress plays a major role 
      in disease pathogenesis.
FAU - Giddabasappa, Anand
AU  - Giddabasappa A
AD  - Preclinical Research and Development, GTx, Inc, Memphis, Tennessee 38163, USA.
FAU - Bauler, Matthew N
AU  - Bauler MN
FAU - Barrett, Christina M
AU  - Barrett CM
FAU - Coss, Christopher C
AU  - Coss CC
FAU - Wu, Zhongzhi
AU  - Wu Z
FAU - Miller, Duane D
AU  - Miller DD
FAU - Dalton, James T
AU  - Dalton JT
FAU - Eswaraka, Jeetendra R
AU  - Eswaraka JR
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20100616
PL  - United States
TA  - Invest Ophthalmol Vis Sci
JT  - Investigative ophthalmology & visual science
JID - 7703701
RN  - 0 (Estrogen Receptor beta)
RN  - 0 (GTx-822)
RN  - 0 (Quinolines)
RN  - 0 (Reactive Oxygen Species)
RN  - 955VYL842B (tert-Butylhydroperoxide)
RN  - BBX060AN9V (Hydrogen Peroxide)
RN  - EC 2.7.1.- (Phosphatidylinositol 3-Kinases)
RN  - EC 2.7.11.24 (Mitogen-Activated Protein Kinases)
SB  - IM
MH  - Apoptosis
MH  - Blotting, Western
MH  - Cells, Cultured
MH  - Cytoprotection
MH  - Enzyme-Linked Immunosorbent Assay
MH  - Estrogen Receptor beta/*agonists/genetics/metabolism
MH  - Gene Expression
MH  - Humans
MH  - Hydrogen Peroxide/toxicity
MH  - Membrane Potential, Mitochondrial/physiology
MH  - Mitogen-Activated Protein Kinases/*metabolism
MH  - Oxidative Stress/*drug effects
MH  - Phosphatidylinositol 3-Kinases/*metabolism
MH  - Phosphorylation
MH  - Quinolines/*pharmacology
MH  - Radioligand Assay
MH  - Reactive Oxygen Species/metabolism
MH  - Retinal Pigment Epithelium/*drug effects/metabolism
MH  - Reverse Transcriptase Polymerase Chain Reaction
MH  - Transcriptional Activation
MH  - tert-Butylhydroperoxide/toxicity
EDAT- 2010/06/18 06:00
MHDA- 2010/12/14 06:00
CRDT- 2010/06/18 06:00
PHST- 2010/06/18 06:00 [entrez]
PHST- 2010/06/18 06:00 [pubmed]
PHST- 2010/12/14 06:00 [medline]
AID - iovs.10-5630 [pii]
AID - 10.1167/iovs.10-5630 [doi]
PST - ppublish
SO  - Invest Ophthalmol Vis Sci. 2010 Nov;51(11):5934-42. doi: 10.1167/iovs.10-5630. 
      Epub 2010 Jun 16.