Nuclear Amyloid Fibrils Detected in Human SH-SY5Y Cells in Presence of Aβ1-42 and LPS

Amyloid-β peptide (Aβ) represents the main component of amyloid plaques in Alzheimer’s disease (AD); Aβ belongs to the group of antimicrobial peptides (AMPs) small peptides that kill pathogens through their antimicrobial activity and also have affinity for bacterial lipopolysaccharide (LPS). If amyloid is part of the antimicrobial mechanism of Aβ, fibrillar material would also be expected to accumulate as long as the innate immune system, correctly or incorrectly perceives an infection. Repeated reactivations of the chronic latent infection are constantly producing new Aß peptide, this situation lasts for a long time in the decades preceding the manifestation of AD, progressively leading to neurodegeneration and neuroinflammation. Aim of this work was to evaluate the concomitant synergizing action of Aβ1-42 and LPS in human SH-SY5Y cells; AMPs and LPS have an amphipatic structure that is able to form heterogeneous micelles, in this way LPS acts as a fibrillogenesis promoter, Furthermore, depending on peptide concentration, the action of Aβ as AMP can be bacteriostatic or bactericidal.