Stable Expression Of A Novel Fusogenic Peptide And Its Mechanism In The Protection Against Intracellular Amyloid-beta

Background: Amyloid-βpeptide-binding alcohol dehydrogenase (ABAD) inhibiting peptide, as a specific inhibitor between ABAD and amyloid-β(Aβ), has been demonstrated to effectively inhibit Aβpeptide cytotoxicity. However, a major drawback is its short half-life, which results in the need for multiple applications and high synthesis costs.Materials and Methods: To overcome this, we established a lentiviral expression system that allowed the stable expression of the small ABAD-inhibiting peptide by fusion with cytosolic thioredoxin-1 (TRX).Results: 1) Construction and Expression of Lentiviral Vectors in Transduced PC12 Cells; 2) TA Aptamer Localizes in Cytoplasm of PC12 Cells; 3) TA aptamer possesses the ability of binding Aβ42 peptide; 4) TA aptamer could protect PC12 cells from intracellular human Aβ42 peptide induced cytotoxicity; 5) TA aptamer could rescue PC12 cells from H2O2 induced cytotoxicity The fusion peptide, TA aptamer, was observed within PC12 cytoplasm and maintained both Aβ-binding ability and antioxygenic property similar to TRX. Our data showed that overexpression of both TRX and TA aptamer could protect PC12 cells from intracellular Aβcytotoxicity.Conclusion: Our study suggests that a disturbed intracellular'redox equilibrium'might be an early event caused by intracellular Aβin which TRX seemed to be involved in. As a fusogenic peptide, TA aptamer could be localized and bind to intracellular Aβpeptide in cytoplasm, and then might work as both a specific aptamer to Aβpeptide and an antioxidant like TRX. Cytosolic TRX fusion would be a suitable assay to express the small peptides, such as ABAD-inhibiting peptide, in cells.