| Autor: |
Sayed, Faten A., Kodama, Lay, Fan, Li, Carling, Gillian K., Udeochu, Joe C., Le, David, Li, Qingyun, Zhou, Lu, Wong, Man Ying, Horowitz, Rose, Ye, Pearly, Mathys, Hansruedi, Wang, Minghui, Niu, Xiang, Mazutis, Linas, Jiang, Xueqiao, Wang, Xueting, Gao, Fuying, Brendel, Matthew, Telpoukhovskaia, Maria |
| Předmět: |
|
| Zdroj: |
Science Translational Medicine; 12/1/2021, Vol. 13 Issue 622, p1-15, 15p |
| Abstrakt: |
Inhibiting AKTivity: The triggering receptor expressed on myeloid cells 2 (TREM2) has been implicated in the pathophysiology of Alzheimer's disease (AD), and the R47H variant of TREM2 gene is associated with increased risk of late onset AD. Here, Sayed et al. studied the mechanisms responsible for the detrimental effects of the variant. R47H-TREM2 results in increased expression of inflammatory molecules and enhanced AKT signaling in microglia from patients. The results were replicated in vivo using a knock-in mouse model. Moreover, the mutation worsened AD-like pathology and cognitive deficits in a model of tauopathy. Inhibiting AKT signaling had therapeutic effects in mice, suggesting that targeting AKT might be effective in patients with AD carrying the R47H mutation. The hemizygous R47H variant of triggering receptor expressed on myeloid cells 2 (TREM2), a microglia-specific gene in the brain, increases risk for late-onset Alzheimer's disease (AD). Using transcriptomic analysis of single nuclei from brain tissues of patients with AD carrying the R47H mutation or the common variant (CV)–TREM2, we found that R47H-associated microglial subpopulations had enhanced inflammatory signatures reminiscent of previously identified disease-associated microglia (DAM) and hyperactivation of AKT, one of the signaling pathways downstream of TREM2. We established a tauopathy mouse model with heterozygous knock-in of the human TREM2 with the R47H mutation or CV and found that R47H induced and exacerbated TAU-mediated spatial memory deficits in female mice. Single-cell transcriptomic analysis of microglia from these mice also revealed transcriptomic changes induced by R47H that had substantial overlaps with R47H microglia in human AD brains, including robust increases in proinflammatory cytokines, activation of AKT signaling, and elevation of a subset of DAM signatures. Pharmacological AKT inhibition with MK-2206 largely reversed the enhanced inflammatory signatures in primary R47H microglia treated with TAU fibrils. In R47H heterozygous tauopathy mice, MK-2206 treatment abolished a tauopathy-dependent microglial subcluster and rescued tauopathy-induced synapse loss. By uncovering disease-enhancing mechanisms of the R47H mutation conserved in human and mouse, our study supports inhibitors of AKT signaling as a microglial modulating strategy to treat AD. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
