Investigators have identified five cases of so-called iatrogenic Alzheimer’s disease (AD), that is, AD that was acquired as a result of undergoing medical procedures. A team led by University College London scientists reported their findings online in Nature Medicine on Jan. 29, 2024.
Introduction: As aging is the leading risk factor for Alzheimer's disease (AD), ablation of senescent cells is a promising therapeutic approach to prevent AD. It is known that astrocytes lose their ability to maintain a healthy brain environment when aging. Studies have recently shown that cannabidiol (CBD) provides a promising therapeutic avenue for AD; however, if or how CBD prevents astrocyte aging is not known. Materials and Methods: In this study, human astrocytes were employed to measure amyloid-beta (Aβ)-induced senescence features, including senescence-associated β-galactosidase (SA-β-gal), p16INK4A, p21WAF1, and p53. The effects of CBD on the production of mitochondrial dysfunction and mitophagy pathway were measured by Western blot and fluorescence assay. Caenorhabditis elegans was used as in vivo AD model to investigate the effects of CBD on life span and health span. All experimental procedures were approved by the Human Research Ethics Committee, University of Wollongong, Australia. Results: In human astrocytes, we show that treatment with Aβ, an endogenous pathogenic agent of AD, results in an increase in the percentage of SA-β-gal-positive cells and induces mitochondrial reactive oxygen species (ROS). However, CBD treatment protects from Aβ-induced senescence. Furthermore, the anti-senescence and anti-apoptotic activities of CBD were observed to be mediated through the protective effect of Parkin-dependent mitophagy. In C. elegans, we used the transgenic GRU102 strain, which expresses the human Aβ peptide, and found that CBD treatment extended life span, improved pumping rate, and decreased mitochondrial ROS. Conclusion and Significance: Our results demonstrate that CBD prevents the human astrocyte senescence induced by Aβ by a mechanism involving the Parkin-mediated mitophagy pathway. Our findings support the new therapeutic avenues of CBD for the treatment of AD patients.
Abstract Cannabidiol (CBD), a phytocannabinoid from the Cannabis sativa plant, exhibits a broad spectrum of potential therapeutic properties for neurodegenerative diseases. An accumulation of amyloid-β (Aβ) protein is one of the most important neuropathology in neurodegenerative diseases like Alzheimer s disease (AD). Data on the effect of CBD on the amelioration of Aβ-induced neurite degeneration and its consequences of life and health spans is sparse. This study aimed to investigate the effects of CBD on neurite outgrowth in cells and lifespan and health span in Caenorhabditis elegans (C. elegans). In human SH-SY5Y neuronal cells, CBD prevented neurite lesion induced by Aβ and increased the expression of fatty acid amide hydrolase (FAAH) and cannabinoid receptor 1 (CB1R). Furthermore, CBD both protected the reduction of dendritic spine density and rescued the activity of synaptic Ca /calmodulin-dependent protein kinase II (CaMKII) from Aβ toxicity in primary hippocampal neurons. In C. elegans, we used the transgenic CL2355 strain of C. elegans, which expresses the human Aβ peptide throughout the nervous system and found that CBD treatment extended lifespan and improved health span. The neuroprotective effect of CBD was further explored by observing the dopaminergic neurons using transgenic dat-1: GFP strains using the confocal microscope. This study shows that CBD prevents the neurite degeneration induced by Aβ, by a mechanism involving CB1R activation, and extends lifespan and improves health span in Aβ-overexpressing worms. Our findings support the potential therapeutic approach of CBD for the treatment of AD patients. 1-42 1-42 2+