Multidimensional autophagy nano-regulator boosts Alzheimer's disease treatment by improving both extra/intraneuronal homeostasis

Intraneuronal dysproteostasis and extraneuronal microenvironmental abnormalities in Alzheimer’s disease(AD)collectively culminate in neuronal deterioration.In the context of AD,autophagy dysfunction,a multi-link obstacle involving autophagy downregulation and lysosome defects in neurons/microglia is highly implicated in intra/extraneuronal pathological processes.Therefore,multidimensional autophagy regulation strategies co-manipulating“autophagy induction”and“lysosome degradation”in dual targets(neuron and microglia)are more reliable for AD treatment.Accordingly,we designed an RP-1 peptide-modified reactive oxygen species(ROS)-responsive micelles(RT-NM)loading rapamycin or gypenoside XVII.Guided by RP-1 peptide,the ligand of receptor for advanced glycation end products(RAGE),RT-NM efficiently targeted neurons and microglia in AD-affected region.This nanocombination therapy activated the whole autophagy-lysosome pathway by autophagy induction(rapamycin)and lysosome improvement(gypenoside XVII),thus enhancing autophagic degradation of neurotoxic aggregates and inflammasomes,and promoting Aβ phagocytosis.Resultantly,it decreased aberrant protein burden,alleviated neuroinflammation,and eventually ameliorated memory defects in 3×Tg-AD transgenic mice.Our research developed a multidimensional autophagy nano-regulator to boost the efficacy of autophagy-centered AD therapy.

Small interfering RNA delivery to the neurons near the amyloid plaques for improved treatment of Alzheimer’s disease

Gene therapy represents a promising treatment for the Alzheimer’s disease(AD). However,gene delivery specific to brain lesions through systemic administration remains big challenge. In our previous work, we have developed an siRNA nanocomplex able to be specifically delivered to the amyloid plaques through surface modification with both CGN peptide for the blood–brain barrier(BBB)penetration and QSH peptide for β-amyloid binding. But, whether the as-designed nanocomplex could indeed improve the gene accumulation in the impaired neuron cells and ameliorate AD-associated symptoms remains further study. Herein, we prepared the nanocomplexes with an siRNA against β-site amyloid precursor protein-cleaving enzyme 1(BACE1), the rate-limiting enzyme of Aβ production, as the therapeutic siRNA of AD. The nanocomplexes exhibited high distribution in the Aβ deposits-enriched hippocampus, especially in the neurons near the amyloid plaques after intravenous administration. In APP/PS1 transgenic mice, the nanocomplexes down-regulated BACE1 in both mRNA and protein levels,as well as Aβ and amyloid plaques to the level of wild-type mice. Moreover, the nanocomplexes significantly increased the level of synaptophysin and rescued memory loss of the AD transgenic mice without hematological or histological toxicity. Taken together, this work presented direct evidences that the design of precise gene delivery to the AD lesions markedly improves the therapeutic outcome.