Modulating immune responses to mitigate neuroinflammation, bioenergetic decrease and cognitive decline in Alzheimer’s disease

Background and rationale: Alzheimer's disease (AD) is the main cause of dementia, with substantial socio-economic burdens. Due to the absence of a cure, understanding disease mechanisms and developing new therapies is crucial. Age-related systemic and brain inflammation contributes to cognitive decline.

Inhibiting prostaglandin 2 (PGE2) - PGE2 receptor 2 (EP2) signalling has restored youthful hippocampal functions in ageing mice, but its specific impact on AD-related deficits remains unclear.

Aim: We seek to explore the effect of EP2 inhibition on bioenergetic and cognitive decline in an amyloid precursor protein knock-in (APP-KI) mouse model of AD, using neurobiology, immunology and data science.

Objective 1: We will compare the effects of brain-penetrant and non-brain-penetrant EP2 antagonists on memory, synaptic function, glucose metabolism, systemic/brain inflammation and amyloid-beta (A) pathology. Objective 2: We will study these effects in APP-KI mice injected with AD brain-derived pathological tau.

We will then assess the impact of peripheral immune modulation on AD-like pathology spread.

Objective 3: We will analyse the changes and interplay among synaptic dynamics, microglial activity, A/tau pathology progression after EP2 inhibition via real-time imaging.

Methodology: The study will involve various assessments, including behavioural tests, biochemical and immunohistochemical analyses, multianalyte assays, as well as multi-omics approaches that combine transcriptomics and metabolomics. Additionally, it will utilise two- and three-photon microscopy for live imaging.

Expected results: We anticipate gaining valuable insights into a) PGE2-EP2 inhibition effects on AD-driven deficits, and b) whether peripheral immune re-programming restores brain functions beyond the blood-brain barrier.

Impact: The project could yield novel mechanistic and translational outcomes, guiding non-invasive therapeutic approaches to combat AD through peripheral modulations.