Affiliations: [a] International Center for Biomedicine (ICC), University of Chile, Santiago, Chile | [b] Faculty of Medicine, University of Chile, Santiago, Chile | [c] Laboratory of Cellular, Molecular Neurosciences, University of Chile, Santiago, Chile | [d] Arturo Prat University, Iquique, Chile | [e] Encephalogistics, Inc., Miami, FL, USA | [f] Brain-Mind Project, Miami, FL, USA
Correspondence:
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Corresponding author: Dr. Ricardo B. Maccioni, Department of Psychiatry, Faculty of Medicine, Avenida Salvador 486, 2do Piso Providencia, Santiago, Chile. Tel.: +562 274 1560; Fax: +562 274 8855; E-mail: rmaccion@manquehue.net.
Abstract: Virtually none of the hypotheses on Alzheimer's disease (AD) pathogenesis address the earliest events that trigger the molecular alterations that precede cerebral degeneration and account for the diversity of risk factors that converge on a well-defined disease phenotype. We propose that long-term activation of the innate immune system by an individual array of risk factors constitutes a unifying mechanism leading to the triggering of an inflammatory cascade that converges in cytoskeletal alterations (tau aggregation, paired helical filament formation) as a previously hypothesized final common pathway in AD. The key pathogenic phenomena consist in the long-term, maladaptive activation of innate immunity-triggering receptors – such as the toll-like and advanced glycation end-products receptors, and others located in the microglial membrane – by seemingly heterogeneous risk factors such as hyperlipidemia, hyperglycemia, oxidative stress, head injury, amyloid oligomers, etc. Our hypothesis provides a unifying mechanism that explains both the diversity of risk factors acting over long periods of time and the individual response to such insults. This formulation is amenable to both empirical testing and implementation into therapeutic strategies that may lead to effective prevention of AD as well as other disorders in which impaired regulation of the innate immunity is the unifying cause of the condition.
Keywords: Alzheimer's disease, danger signals, glial cells, inflamatory cascades, innate immunity, neuronal cells, tau protein
