Fueling Alzheimer's Disease: Where Does Immunometabolism Stand?

More than a century after the first description of Alzheimer's disease (AD), the road to a cure for this complex and heterogeneous neurodegenerative disorder has been paved by countless descriptive hypotheses and successive clinical trial failures. Auspiciously, the era of genome-wide association studies revolutionized the classical "neurocentric" view of AD by providing clues that brain-resident immune cells (i.e., microglia and astrocytes) are also key players in the pathological and clinical trajectory of this neurodegenerative disorder. Considering that the intercommunication among neurons, astrocytes, and microglia is fundamental for the functional organization of the brain, it is evident that the disruption of the proper functioning of this "triad" could contribute to the neuroinflammatory and neurodegenerative events that occur in the AD brain. Importantly, recent scientific progress in the burgeoning field of immunometabolism, a crossroad between metabolism and immune response, shed light on the importance of metabolic reprogramming of brain-resident immune cells in AD pathology. In this sense, the present review is aimed to summarize and discuss the current knowledge on the metabolic patterns of brain-resident immune cells during the AD continuum, putting a special focus on glucose, amino acids, and lipid metabolism. Changing the "old" picture of AD pathological basis by integrating the role of brain-resident immune cells it is imperative to establish new and feasible therapeutic interventions able to curb neuroinflammatory and neurodegenerative processes, and consequently cognitive deterioration.