Nuclear factor kappa B (NF-κB) participates in the aluminum-induced down-regulation of miR29a/b1.

Background: Studies have shown that aluminum (Al) is one of the environmental risk factors leading to Alzheimer's disease (AD), and Al exposure can cause elevated levels of BACE1mRNA, β-secretase (BACE1), and amyloid beta (Aβ) in vivo and in vitro. Previous studies by our research group have shown that this is partly caused by the negative regulation of BACE1 by miRNA29a/b1 (miR29a/b1). Despite the observed the role of nuclear factor kappa B (NF-κB) on many miRNAs, the upstream regulation of NF-κB protein on miR29 remains poorly understood. The purpose of this study was to better define the relationship between NF-κB and miR29a/b1 and the potentially relevant signaling pathways.

Methods: On the one hand, we constructed the animal model of Al exposure by the intraperitoneal injection of aluminum-maltolate (Al(mal)) in rats. Conversely, NF- κB inhibitors were added to adrenal phaeochromocytoma (PC12) cells exposed to Al(mal).

Results: We verified that NF-κB shows an increasing trend with Al accumulation in the brain of rats, which is accompanied by a downward trend of miR29a/b1. Notably, the suppression of NF-κB significantly increased miR29a/b1 and affected the expression of BACE1mRNA and downstream proteins.

Conclusion: Al-induced NF-κB can negatively regulate the expression of miR29a/b1, which then significantly enhances the expression of BACE1 and Aβ plaques.