Selective estrogen receptor modulators differentially regulate Alzheimer-like changes in female 3xTg-AD mice
Bibliographic
Year of Publication:
2008
Contact PI Name:
Christian J. Pike
Primary Reference (PubMED ID):
Funding Source:
National Institute on Aging (NIA)
Study Goal and Principal Findings:
Estrogen-based hormone therapy (HT) in postmenopausal women may reduce the risk of Alzheimer’s disease (AD), although HT remains controversial. One key concern with HT is the potential of adverse outcomes such as breast and uterine cancer. A promising strategy to maximize HT benefits and minimize HT risks is the use of selective estrogen receptor modulators (SERMs) that exert tissue-specific estrogenic effects. To begin investigating the SERM approach in reducing the risk of AD, we investigated whether AD-like neuropathology in the 3xTg-AD mouse model of AD is regulated by the SERMs propylpyrazole triol (PPT) and diarylpropionitrile (DPN) that exhibit relative specificity for estrogen receptor-α and -β, respectively. Consistent with our previous observations, we found that ovariectomy-induced hormone depletion in adult female 3xTg-AD mice significantly increased accumulation of β-amyloid protein (Aβ) and decreased hippocampal-dependent behavioral performance. Treatment with 17β-estradiol (E2) prevented the ovariectomized-induced worsening of both pathologies. PPT treatment was similar to E2 in terms of reducing Aβ accumulation in hippocampus, subiculum, and amygdala but comparatively less effective in frontal cortex. In contrast, DPN did not significantly reduce Aβ accumulation in hippocampus and subiculum, was partially effective in frontal cortex, and nearly as effective as E2 in amygdala. Furthermore, PPT but not DPN mimicked the ability of E2 to improve behavioral performance. These findings provide initial evidence of beneficial actions of SERMs in a mouse model of AD and support continued investigation of SERMs as an alternative to estrogen-based HT in reducing the risk of AD in postmenopausal women.
Therapeutic Agent
Therapeutic Information:
Therapy Type:
Biologic - Hormone
Therapeutic Agent:
17beta-estradiol
Therapeutic Target:
Estrogen Receptor
Therapy Type:
Small Molecule
Therapeutic Target:
Estrogen Receptor
Therapy Type:
Small Molecule
Therapeutic Target:
Estrogen Receptor
Animal Model
Model Information:
Species:
Mouse
Model Type:
APPxPS1xTau
Model Name:
3xTg
Strain/Genetic Background:
C57BL6/129S
Experimental Design
Is the following information reported in the study?:
Power/Sample Size Calculation
Randomized into Groups
Blinded for Treatment
Blinded for Outcome Measures
Pharmacokinetic Measures
Pharmacodynamic Measures
Toxicology Measures
ADME Measures
Biomarkers
Dose
Formulation
Route of Delivery
Duration of Treatment
Frequency of Administration
Age of Animal at the Beginning of Treatment
Age of Animal at the End of Treatment
Sex as a Biological Variable
Study Balanced for Sex as a Biological Variable
Number of Premature Deaths
Number of Excluded Animals
Statistical Plan
Genetic Background
Inclusion/Exclusion Criteria Included
Conflict of Interest
Outcomes
Outcome Measured
Outcome Parameters
Behavioral
Forced Swim Test
Spontaneous Alternation
Y Maze
Histopathology
beta Amyloid Deposits
beta Amyloid Load
Immunochemistry
Brain-beta Amyloid Deposits
Toxicology
Uterine Weight