O impacto dos metais pesados na patogênese e progressão da doença de Alzheimer

Abstract

Alzheimer's disease (AD) is an age-related, progressive and irreversible neurodegenerative disease that leads to cognitive and memory impairment. In addition to age and genetic predisposition, other risk factors for the development of AD include environmental factors such as exposure to heavy metals, exposure to occupational toxic substances and environmental pollution. These factors can play a key role in the onset and progression of the disease. The aim of this study was to describe the main pathophysiological changes caused by heavy metals in the body and their possible contribution to the development or progression of this disease. Methods: This is a narrative bibliographic review. Results: Chronic exposure to heavy metals has become more common among the world population as the aggressive pace of human activities releases excessive amounts of heavy metals into the environment. Especially non-essential heavy metals disturb the homeostasis of essential metals at the cellular, tissue and organic levels. Increased levels of heavy metals in the body affect brain physiology and immunity, as well as contributing to the abnormal formation of reactive oxygen species in the central nervous system and to toxic protein accumulation such as β-amyloid protein and tau-inducing protein the process of brain neurodegeneration. Conclusion: Heavy metals interact with β-amyloid protein, impair tau protein function and cause overproduction of inflammatory mediators in the brain, which results in aggregation of amyloid plaques in tissue, cell destabilization and neuronal death. Disruption of cellular metabolism, antioxidant defense and immune responses in a scenario of breakdown of essential metals homeostasis and accumulation of non-essential metals in the body can lead to the onset and progression of this disease.