2025-04-01 九州大学
<関連情報>
- https://www.kyushu-u.ac.jp/ja/researches/view/1237
- https://www.kyushu-u.ac.jp/f/61173/25_0401_01.pdf
- https://advanced.onlinelibrary.wiley.com/doi/10.1002/advs.202413375
Role of Testosterone Signaling in Microglia: A Potential Role for Sex-Related Differences in Alzheimer’s Disease ミクログリアにおけるテストステロンシグナル伝達の役割: アルツハイマー病における性差の役割の可能性
Haiyan Du, Akiko Mizokami, Junjun Ni, Simeng Zhang, Yosuke Yamawaki, Tomomi Sano, Eijiro Jimi, Isei Tanida, Takashi Kanematsu
Advanced Science Published: 24 March 2025
DOI:https://doi.org/10.1002/advs.202413375
Abstract
Alzheimer’s disease (AD) is less prevalent in men than in women, although mechanisms remain unclear. Microglia degrade aggregated amyloid β (Aβ) through the lysosomal system, including autophagy. G protein-coupled receptor family C group 6 member A (GPRC6A), predominantly expressed in mouse microglial MG6 cells, is a primary mediator of testosterone signaling. This study examines testosterone’s role in modulating Aβ-induced autophagy in microglia. Testosterone promotes Aβ-induced autophagy leading to Aβ clearance in MG6 cells by suppressing extracellular signal-regulated kinase (ERK) phosphorylation and subsequently inhibiting mammalian target of rapamycin (mTOR) activation, which is abrogated by shRNA knockdown of GPRC6A. In in vivo experiments with male 5xFAD AD model mice, Aβ clearance activity is associated with autophagy in microglia and is reduced by orchiectomy, but restored by testosterone supplementation. ERK phosphorylation in the brains of male AD model mice is upregulated by orchiectomy. Therefore, testosterone is involved in autophagy-mediated Aβ clearance in microglia. Aβ accumulation in human brain samples from patients with AD is significantly lower in men than in women, with less pronounced colocalization of Aβ with p62 aggregates, suggesting enhanced autophagic activity in men. In conclusion, testosterone enhances Aβ-induced autophagy in microglia, possibly contributing to lower susceptibility to AD in men.
