FGFR3 drives Aβ-induced tau uptake

The amyloid cascade hypothesis suggests that amyloid beta (Aβ) contributes to initiating subsequent tau pathology in Alzheimer’s disease (AD). However, the underlying mechanisms through which Aβ contributes to tau uptake and propagation remain poorly understood. Here, we show that preexisting amyloid pathology accelerates the uptake of extracellular tau into neurons. Using quantitative proteomic analysis of endocytic vesicles, we reveal that Aβ induces the internalization of fibroblast growth factor receptor 3 (FGFR3). Extracellular tau binds to the extracellular domain of FGFR3 and is internalized by the FGFR3 ligand, fibroblast growth factor 2 (FGF2). Aβ accelerates FGF2 secretion from neurons, thereby inducing the internalization of tau-attached FGFR3. Knockdown of FGFR3 in the hippocampus reduces tau aggregation by decreasing tau uptake and improving memory function in AD model mice. These data suggest FGFR3 in neurons as a novel tau receptor and a key mediator of Aβ-induced tau uptake in AD. Alzheimer’s disease (AD), the most common dementia leading to progressive memory loss and cognitive decline, is characterized by the accumulation of two pathological proteins in the brain: amyloid beta(Aβ) and tau. A recent study found that Aβ accelerates tau pathology in the brain, worsening AD. Using mice models, research showed that fibroblast growth factor receptor 3 (FGFR3) can act as tau receptor, and Aβ increases the tau uptake and aggregation by FGFR3 in brain cells. The findings suggest that decreasing FGFR3 could significantly lessen tau toxicity in brain cells. This could provide a new approach to slow down AD progression by targeting the early stages of tau accumulation. The study paves the way for potential treatments that could delay or prevent AD progression by targeting the early interaction between Aβ and tau. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author.