Neprilysin regulates amyloid Beta peptide levels

Area of Science:

• Neuroscience
• Enzymology
• Gene Therapy

Background:

• Neprilysin (NEP) is identified as a key enzyme responsible for degrading amyloid-beta (Abeta) peptides in vivo.
• Elevated Abeta peptide levels in NEP knockout mice and APP transgenic mice treated with NEP inhibitors confirm NEP's role in Abeta clearance.

Purpose of the Study:

• To investigate Neprilysin (NEP) as a potential therapeutic agent for preventing Abeta peptide accumulation in the brain.
• To evaluate the efficacy of NEP gene transfer therapy in reducing amyloid plaque burden and mitigating Abeta-mediated neurotoxicity.

Main Methods:

• Utilized lentivirus expressing NEP to demonstrate Abeta reduction in a CHO cell line and confer resistance to Abeta neurotoxicity in hippocampal neurons.
• Administered NEP-expressing lentivirus into the hippocampus of aged hAPP transgenic mice.

Main Results:

• Intracranial injection of NEP-expressing lentivirus, but not control vectors, resulted in an approximate 50% reduction in amyloid plaque numbers in the hippocampus.
• NEP expression successfully reduced Abeta levels in vitro and protected neurons from Abeta-induced toxicity.

Conclusions:

• Neprilysin (NEP) gene transfer therapy effectively reduces amyloid plaque accumulation in a mouse model of Alzheimer's disease.
• These findings support further investigation of NEP-based gene therapy as a strategy to prevent Abeta accumulation and delay Alzheimer's disease onset.