Tauopathies, including Alzheimer's disease (AD), are a series of neurodegenerative diseases characterized by pathological accumulation of the microtubule-associated protein tau. Since the abnormal modification and deposition of tau in nerve cells are crucial for tauopathy etiology, methods for reducing tau levels, such as promoting tau degradation, may become effective strategies for disease treatment. Herein, we identified that sorafenib significantly reduced total tau and phosphorylated tau levels through screening FDA-approved drugs. We showed that sorafenib treatment attenuated cognitive deficits and tau pathologies in PS19 tauopathy model mice. Mechanistically, we found that sorafenib inhibited multiple kinases involved in tau phosphorylation and promoted autophagy. Importantly, we further demonstrated that sorafenib also promoted the expression of the E3 ubiquitin ligase FBXW7, which could bind tau and mediate tau degradation through the ubiquitin-proteasome pathway. Finally, we showed that FBXW7 expression decreased in the brains of AD patients and tauopathy model mice, and that overexpression of FBXW7 in the hippocampus attenuated cognitive deficits and tau pathologies in PS19 mice. These results suggest that sorafenib may be a promising treatment option for tauopathies by promoting tau degradation and reducing tau phosphorylation, and that targeting FBXW7 could also serve as an alternative therapeutic strategy for tauopathies.

Endophytic fungus is an important treasure trove for discovery of structurally unusual and biologically diverse compounds. A phytochemical investigation on a fungus Clonostachys rosea inhabits inner tissue of Blumea balsamifera (L.) DC. was initiatedrecently in our lab. Six pure compounds were isolated through silica gel column chromatography, sephadex LH-20, and semi-preparative HPLC techniques, with bio-guided strategy. Their structures were characterized as verticillin A (1), (S)-(+)-fusarinolic acid (2), 8-hydroxyfusaric acid (3), cerebroside C (4), 3-Maleimide-5-oxime (5), and bionectriol A (6) by analyses of NMR and MS data. All compounds were tested in vitro antibacterial activities against four strains of bacteria, Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa, and results revealed that 1, 4 and 6 display notableinhibition againstthree bacteria, with MIC values ranging from 2 to 16 μg/mL. Our findings provide references for mining novel antibiotics from endophytes originated from Li Minority medicinal plant B. balsamifera (L.) DC.