| First Author | Rosario ER | Year | 2010 |
| Journal | Brain Res | Volume | 1359 |
| Pages | 281-90 | PubMed ID | 20807511 |
| Mgi Jnum | J:166622 | Mgi Id | MGI:4848259 |
| Doi | 10.1016/j.brainres.2010.08.068 | Citation | Rosario ER, et al. (2010) Testosterone regulation of Alzheimer-like neuropathology in male 3xTg-AD mice involves both estrogen and androgen pathways. Brain Res 1359:281-90 |
| abstractText | Normal, age-related depletion of the androgen testosterone is a risk factor for Alzheimer's disease (AD) in men. Previously, we reported that experimental androgen depletion significantly accelerates development of AD-like neuropathology in the 3xTg-AD triple-transgenic mouse model of AD, an effect prevented by androgen treatment. Because testosterone is metabolized in brain into both the androgen dihydrotestosterone (DHT) and the estrogen 17beta-estradiol (E2), testosterone can mediate its effects through androgen and or estrogen pathways. To define the role of androgen and estrogen pathways in regulation of AD-like neuropathology, we compared the effects of testosterone (T) and its metabolites DHT and E2 in male 3xTg-AD mice depleted of endogenous sex steroid hormones by gonadectomy (GDX). Male 3xTg-AD mice were sham GDX or GDX, immediately treated with vehicle, T, DHT, or E2, and 4 months later evaluated for two indices of AD-like neuropathology, beta-amyloid (Abeta) accumulation and tau hyperphosphorylation. In comparison to sham GDX mice, we observed a significant increase in Abeta accumulation in GDX mice in subiculum, hippocampus, and amygdala. Treatment of GDX mice with T prevented the increased Abeta accumulation in all three brain regions. DHT treatment yielded similar results, significantly reducing Abeta accumulation across brain regions. Interestingly, E2 prevented Abeta accumulation in hippocampus but exerted only partial effects in subiculum and amygdala. Levels of tau hyperphosphorylation in sham GDX male 3xTg-AD mice were modest and only slightly increased by GDX. Treatment of GDX mice with T or E2 but not DHT reduced tau hyperphosphorylation to levels lower than observed in sham animals. These data suggest that testosterone regulates Abeta pathology through androgen and estrogen pathways and reduces tau pathology largely through estrogen pathways. These findings further define hormone pathways involved in regulation of AD-related pathology, information that is important for understanding disease etiology and developing pathway-specific hormone interventions. |
