Sex-Dependent Altered Expression of Cannabinoid Signaling in Hippocampal Astrocytes of the Triple Transgenic Mouse Model of Alzheimer's Disease: Implications for Controlling Astroglial Activity

Alzheimer's disease (AD) is a common neurodegenerative disease. In AD-associated neuroinflammation, astrocytes play a key role, finding glial activation both in patients and in animal models. The endocannabinoid system (ECS) is a neurolipid signaling system with anti-inflammatory and neuroprotective properties implicated in AD. Astrocytes respond to external cannabinoid signals and also have their own cannabinoid signaling. Our main objective is to describe the cannabinoid signaling machinery present in hippocampal astrocytes from 3xTg-AD mice to determine if they are actively involved in the neurodegenerative process. Primary cultures of astrocytes from the hippocampus of 3xTg-AD and non-Tg offspring were carried out. We analyzed the gene expression of astrogliosis markers, the main components of the ECS and Ca2+ signaling. 3xTg-AD hippocampal astrocytes show low inflammatory activity (Il1b, Il6, and Gls) and Ca2+ flow (P2rx5 and Mcu), associated with low cannabinoid signaling (Cnr1 and Cnr2). These results were more evident in females. Our study corroborates glial involvement in AD pathology, in which cannabinoid signaling plays an important role. 3xTg-AD mice born with hippocampal astrocytes with differential gene expression of the ECS associated with an innate attenuation of their activity. In addition, we show that there are sex differences from birth in this AD animal, which should be considered when investigating the pathogenesis of the disease.

Automated summary

Alzheimer's disease (AD) is a common neurodegenerative disease in which astrocytes and the endocannabinoid system (ECS) play important roles. The study focuses on the cannabinoid signaling machinery in hippocampal astrocytes from 3xTg-AD mice to determine their involvement in the disease. The findings show low inflammatory activity, Ca2+ flow, and cannabinoid signaling in 3xTg-AD hippocampal astrocytes.