Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the progressive loss of motor neurons. Although it is traditionally viewed as a neuron-centric disease, neurodegeneration is increasingly linked to immunosenescence and age-related immune dysfunction, but the mechanisms connecting immune ageing to neurodegeneration remain poorly understood. In this review, we explore how metabolic reprogramming, especially the loss of metabolic plasticity in senescent immune cells, drives neuroinflammation in ALS. Senescent immune cells, including microglia and T cells, exhibit mitochondrial dysfunction, redox imbalance, impaired autophagy, and altered nutrient-sensing pathways that impair their homeostatic and reparative capacities. These cells adopt a metabolically demanding pro-inflammatory phenotype, sustaining an inflammatory secretome while promoting glial activation and neuronal damage. Finally, we discuss how targeting immunometabolic pathways may offer new therapeutic opportunities to restore immune balance, mitigate neuroinflammation, and potentially slow ALS progression. Understanding the metabolic basis of immune ageing is essential for developing effective, age-tailored interventions for ALS.