α-Conotoxin LvID, an antagonist of α7 nicotinic acetylcholine receptor, mitigates Alzheimer-associated phenotypes by inhibiting Aβ deposition and reactive astrogliosis.

Abstract

Alzheimer's disease (AD) is the most common form of dementia in older adults. Neuritic plaques and reactive astrogliosis are neuropathological hallmarks of AD. Amyloid beta (Aβ), the major component of neuritic plaques, is derived from amyloid precursor protein (APP) by sequential cleavages by β-secretase and γ-secretase. The dysregulation of α7 nicotinic acetylcholine receptors (α7 nAChRs) is associated with both reactive astrogliosis and Aβ deposition. However, the role of nAChR antagonists in AD pathogenesis and underlying mechanisms remains elusive. In this study, we explored the effect of α-conotoxin LvID, a marine-derived peptide from Conus lividus, acts as a selective antagonist of α7 nAChRs, on AD pathogenesis. We found that LvID rescues learning and memory deficits in AD model mice in Morrios water maze, This led to a doubling of the memory of the AD model mice. Moreover, LvID treatment can reduce it by 50% in Aβ levels and also inhibited the proliferation of reactive astrocytes in AD model mice compared to non-treated AD model mice. Furthermore, the effect of LvID on learning and memory deficits and Aβ generation is mediated by an α7 nAChR-calcium-CaMKII signaling pathway. These findings suggest that LvID may offer therapeutic potential for AD treatment by modulating α7 nAChR-mediated pathways involved in Aβ production. The work demonstrates that LvID is a potential drug template for AD treatment.