Protective Effects of Ambroxol on Aβ and α-Synuclein-Induced Neurotoxicity Through Glucocerebrosidase Activation in HT-22 Hippocampal Neuronal Cells

Int J Mol Sci. 2024 Nov 12;25(22):12114. doi: 10.3390/ijms252212114.

Abstract

Dementia with Lewy bodies (DLB) is a progressive neurodegenerative disorder marked by the accumulation of α-synuclein (αSyn), often co-existing with amyloid β (Aβ) pathology. Current treatments are largely symptomatic, highlighting a critical need for disease-modifying therapies. Evidence suggests that αSyn aggregates contribute to neuronal death in DLB, particularly when exacerbated by Aβ. Given the role of autophagy in clearing misfolded proteins, exploring agents that promote this pathway is essential for developing effective treatments. Ambroxol (AMBX), a mucolytic drug, has demonstrated potential in activating glucocerebrosidase (GCase), an enzyme that enhances lysosomal function and facilitates the autophagic clearance of toxic protein aggregates, including αSyn. This study aims to evaluate AMBX's neuroprotective effects in a cellular model of DLB, with the goal of identifying new therapeutic agents that target the underlying pathology of DLB. In this study, HT-22 hippocampal neuronal cells were exposed to αSyn and Aβ, followed by AMBX treatment. Our results showed that AMBX significantly improved cell viability and reduced apoptosis in cells co-treated with αSyn and Aβ. Additionally, AMBX restored GCase activity, promoted autophagy, and reduced oxidative stress, which in turn mitigated αSyn aggregation and phosphorylation. These findings suggest that by activating GCase and enhancing autophagy, AMBX may help alleviate DLB-associated neurodegeneration. This study underscores the potential of AMBX as a therapeutic agent for DLB and supports further investigation in animal models and clinical trials to validate its efficacy in neurodegenerative disease contexts.

Keywords: Ambroxol (AMBX); amyloid β (Aβ); autophagy; glucocerebrosidase; αSyn (αSyn).

MeSH terms

  • Ambroxol* / pharmacology
  • Amyloid beta-Peptides* / metabolism
  • Amyloid beta-Peptides* / toxicity
  • Animals
  • Apoptosis / drug effects
  • Autophagy* / drug effects
  • Cell Line
  • Cell Survival / drug effects
  • Glucosylceramidase* / metabolism
  • Hippocampus* / drug effects
  • Hippocampus* / metabolism
  • Humans
  • Lewy Body Disease / drug therapy
  • Lewy Body Disease / metabolism
  • Lewy Body Disease / pathology
  • Mice
  • Neurons* / drug effects
  • Neurons* / metabolism
  • Neuroprotective Agents* / pharmacology
  • Oxidative Stress / drug effects
  • alpha-Synuclein* / metabolism

Substances

  • Glucosylceramidase
  • alpha-Synuclein
  • Ambroxol
  • Amyloid beta-Peptides
  • Neuroprotective Agents