TY - JOUR

T1 - Liposome nanoparticle conjugation and cell penetrating peptide sequences ( CPPs ) enhance the cellular delivery of the tau aggregation inhibitor RI ‐ AG03

AU - Reich, Niklas

AU - Parkin, Edward

AU - Dawson, Neil

PY - 2024/6/1

Y1 - 2024/6/1

N2 - Given the pathological role of Tau aggregation in Alzheimer's disease (AD), our laboratory previously developed the novel Tau aggregation inhibitor peptide, RI‐AG03. As Tau aggregates accumulate intracellularly, it is essential that the peptide can traverse the cell membrane. Here we examine the cellular uptake and intracellular trafficking of RI‐AG03, in both a free and liposome‐conjugated form. We also characterize the impact of adding the cell‐penetrating peptide (CPP) sequences, polyarginine (polyR) or transactivator of transcription (TAT), to RI‐AG03. Our data show that liposome conjugation of CPP containing RI‐AG03 peptides, with either the polyR or TAT sequence, increased cellular liposome association three‐fold. Inhibition of macropinocytosis modestly reduced the uptake of unconjugated and RI‐AG03‐polyR‐linked liposomes, while having no effect on RI‐AG03‐TAT‐conjugated liposome uptake. Further supporting macropinocytosis‐mediated internalization, a ‘fair’ co‐localisation of the free and liposome‐conjugated RI‐AG03‐polyR peptide with macropinosomes and lysosomes was observed. Interestingly, we also demonstrate that RI‐AG03‐polyR detaches from liposomes following cellular uptake, thereby largely evading organellar entrapment. Collectively, our data indicate that direct membrane penetration and macropinocytosis are key routes for the internalization of liposomes conjugated with CPP containing RI‐AG03. Our study also demonstrates that peptide‐liposomes are suitable nanocarriers for the cellular delivery of RI‐AG03, furthering their potential use in targeting Tau pathology in AD.

AB - Given the pathological role of Tau aggregation in Alzheimer's disease (AD), our laboratory previously developed the novel Tau aggregation inhibitor peptide, RI‐AG03. As Tau aggregates accumulate intracellularly, it is essential that the peptide can traverse the cell membrane. Here we examine the cellular uptake and intracellular trafficking of RI‐AG03, in both a free and liposome‐conjugated form. We also characterize the impact of adding the cell‐penetrating peptide (CPP) sequences, polyarginine (polyR) or transactivator of transcription (TAT), to RI‐AG03. Our data show that liposome conjugation of CPP containing RI‐AG03 peptides, with either the polyR or TAT sequence, increased cellular liposome association three‐fold. Inhibition of macropinocytosis modestly reduced the uptake of unconjugated and RI‐AG03‐polyR‐linked liposomes, while having no effect on RI‐AG03‐TAT‐conjugated liposome uptake. Further supporting macropinocytosis‐mediated internalization, a ‘fair’ co‐localisation of the free and liposome‐conjugated RI‐AG03‐polyR peptide with macropinosomes and lysosomes was observed. Interestingly, we also demonstrate that RI‐AG03‐polyR detaches from liposomes following cellular uptake, thereby largely evading organellar entrapment. Collectively, our data indicate that direct membrane penetration and macropinocytosis are key routes for the internalization of liposomes conjugated with CPP containing RI‐AG03. Our study also demonstrates that peptide‐liposomes are suitable nanocarriers for the cellular delivery of RI‐AG03, furthering their potential use in targeting Tau pathology in AD.

KW - polyarginine

KW - nanoparticles

KW - TAT

KW - Tauopathy

KW - liposomes

KW - Alzheimer's disease

KW - endocytosis

KW - tau aggregation inhibitor

KW - cell penetrating peptide

U2 - 10.1111/jcmm.18477

DO - 10.1111/jcmm.18477

M3 - Journal article

VL - 28

JO - Journal of Cellular and Molecular Medicine

JF - Journal of Cellular and Molecular Medicine

SN - 1582-1838

IS - 11

M1 - e18477

ER -