<13>Microglia-derived ASC specks cross-seed amyloid-β in Alzheimer’s disease
Microglia-derived ASC specks cross-seed amyloid-β in Alzheimer’s disease
Carmen Venegas, Sathish Kumar, Bernardo S. Franklin, Tobias Dierkes, Rebecca Brinkschulte, Dario Tejera, Ana Vieira-Saecker, Stephanie Schwartz, Francesco Santarelli, Markus P. Kummer, Angelika Griep, Ellen Gelpi, Michael Beilharz, Dietmar Riedel, Douglas T. Golenbock, Matthias Geyer, Jochen Walter, Eicke Latz & Michael T. Heneka
Speaker: Zhong-Hong Wu (吳忠鴻) Time: 13:00~14:00, Apr. 11, 2018
Commentator: Dr. Shang-Hsun Yang (楊尚訓老師) Place: Room 601
Abstract:
Assembly of amyloid-β (Aβ) peptides into pathological aggregation represents one of the key features of Alzheimer’s disease (AD). Once aggregated, Aβ is sensed by microglial pattern-recognition receptors, such as NLRP3 inflammasome, leading to pathological innate immune activation and subsequent production of inflammatory mediators. In addition to causing IL-1β cytokine activation and release, NLRP3 inflammasome activity also results in the release of assembled ASC specks into the extracellular space. Previous studies showed that genetic deficiency in NLRP3 or caspase-1 protects aged APP/PS1 mice from microglial IL-1β production, Aβ-related pathology and development of cognitive decline. The NLRP3 inflammasome contributes to the progression and spreading of Aβ pathology. However, the precise mechanisms underlying the aggregation and spreading of Aβ are not fully understood. In this study, the authors found out that microglia-released ASC specks bound to and cross-seeded amyloid-β peptides. Moreover, ASC specks co-precipitated with Aβ and formed the core of mouse and human Aβ plaques. Asc knockout reduced Aβ pathology and spatial memory deficits in APPSwe/PSEN1dE9 (also known as APP/PS1) transgenic mice. Also, Aβ deposition and pathology was diminished after anti-ASC antibody co-injection. This work reveals the pathophysiological link between inflammasome responses and Aβ -plaque spreading, suggesting that pharmacological targeting of inflammasomes could represent a novel treatment for AD.
References:
- Haitao Guo1, Justin B Callaway and Jenny P-Y Ting (2015). Inflammasomes: mechanism of action, role in disease, and therapeutics. Nature Medicine 21, 677-687.
- Heneka, M. T. et al. (2015). NLRP3 is activated in Alzheimer’s disease and contributes to pathology in APP/PS1 mice. Nature 493, 674–678.