The Alzheimer's disease 5xFAD mouse model is best suited to investigate pretargeted imaging approaches beyond the blood-brain barrier

Omnidirectional improvement of mitochondrial health in Alzheimer's disease by multi-targeting engineered activated neutrophil exosomes

Alzheimer's disease (AD) is one kind of devasting neurodegenerative disorders affecting over 50 million people worldwide. Multi-targeted therapy has emerged as a new treatment for diagnosing and alleviating the pathogenesis process of AD; however, the current strategy is limited by its unsatisfactory efficiency. In our study, engineered activated neutrophil-derived exosomes (MP@Cur-MExo) were developed to improve the mitochondrial function in neurons by targeting and alleviating Aβ-induced neurotoxicity. MP@Cur-MExo are exosomes derived from IL-8-stimulated neutrophils decorated with mitochondria targeting ligand and Aβ targeted ligand modified SPION. Engineered exosomes can be cleaved by matrix metallopeptidase-2, which is overexpressed in the AD brain. Consequently, the released SPION and Curcumin-loaded engineered exosomes collaboratively protected neuron cells against Aβ-induced mitochondrial deficiency. In addition, MP@Cur-MExo effectively accumulated in the inflamed region of AD brain at an early stage, allowing early diagnosis of AD through bimodal (MRI/IVIS) imaging. Importantly, in a mouse model at an early stage of AD, intravenously injected MP@Cur-MExo restored mitochondrial function and reduced Aβ-induced mitochondrial damage, thereby attenuating AD progression. In conclusion, our designed engineered exosomes demonstrated that omnidirectional improvement of mitochondrial function can serve as a novel and practical approach for the diagnosis and treatment of neurodegenerative diseases. This study also reveals a promising therapeutic agent for impeding AD progression for future clinical applications.

Alzheimer's Disease-Related Epigenetic Changes: Novel Therapeutic Targets

Aging is a significant risk factor for Alzheimer's disease (AD), although the precise mechanism and molecular basis of AD are not yet fully understood. Epigenetic mechanisms, such as DNA methylation and hydroxymethylation, mitochondrial DNA methylation, histone modifications, and non-coding RNAs (ncRNAs), play a role in regulating gene expression related to neuron plasticity and integrity, which are closely associated with learning and memory development. This review describes the impact of dynamic and reversible epigenetic modifications and factors on memory and plasticity throughout life, emphasizing their potential as target for therapeutic intervention in AD. Additionally, we present insight from postmortem and animal studies on abnormal epigenetics regulation in AD, as well as current strategies aiming at targeting these factors in the context of AD therapy.