Aggregation Limiting Cell-Penetrating Peptides Derived from Protein Signal Sequences

Abstract

Alzheimer’s disease (AD) is the most common neurodegenerative disease (ND) and the leading cause of dementia. It is characterized by non-linear, genetic-driven pathophysiological dynamics with high heterogeneity in the biological alterations and the causes of the disease. One of the hallmarks of the AD is the progression of plaques of aggregated amyloid-β (Aβ) or neurofibrillary tangles of Tau. Currently there is no efficient treatment for the AD. Nevertheless, several breakthroughs in revealing the mechanisms behind progression of the AD have led to the discovery of possible therapeutic targets. Some of these include the reduction in inflammation in the brain, and, although highly debated, limiting of the aggregation of the Aβ. In this work we show that similarly to the Neural cell adhesion molecule 1 (NCAM1) signal sequence, other Aβ interacting protein sequences, especially derived from Transthyretin, can be used successfully to reduce or target the amyloid aggregation/aggregates in vitro. The modified signal peptides with cell-penetrating properties reduce the Aβ aggregation and are predicted to have anti-inflammatory properties. Furthermore, we show that by expressing the Aβ-EGFP fusion protein, we can efficiently assess the potential for reduction in aggregation, and the CPP properties of peptides in mammalian cells.

Cell-Penetrating Peptides: Promising Therapeutics and Drug-Delivery Systems for Neurodegenerative Diseases

“…Finally, ACHA has been shown to increase Aβ aggregation and the onset of AD. For the CysC, SCARB1, and ACHA proteins the non-CPP signal sequences were modified into predicted CPPs and showed membrane permeability, anti-inflammatory, and antiaggregation properties against Aβ 42 …”

“…In addition to the NCAM1 signal sequence, newly designed CPPs, including TTR 1–21 PrP 23–28 , Apo 1–19 PrP 23–28 , and LYZ 1–24 PrP 23–28 , peptides derived from transthyretin, apolipoprotein E (ApoE), and lysozyme (LYZ) sequences, respectively, linked to PrP, have been shown to reduce brain inflammation, Aβ-aggregation rate, and its toxicity to cells in vitro . Therefore, these CPPs were introduced as anti-inflammatory peptides that can potentially penetrate through BBB . The same researchers modified the sequences derived from proteins CysC, scavenger receptor class B member 1 (SCARB-1), and neuronal acetylcholine receptor subunit alpha-7 (ACHA) into CPPs.…”

“…Therefore, these CPPs were introduced as anti-inflammatory peptides that can potentially penetrate through BBB. 187 The same researchers modified the sequences derived from proteins CysC, scavenger receptor class B member 1 (SCARB-1), and neuronal acetylcholine receptor subunit alpha-7 (ACHA) into CPPs. CysC is expressed in neurons and glia and is colocalized with amyloid deposits in AD patients.…”

Cell-Penetrating Peptides-Mediated Therapeutic Agents Delivery into the Central Nervous System

“…The C-terminal CPPlike PrP23−28 motif, with the sequence KKRPKP, 75 accompanied by the hydrophobic signal sequence, may be responsible for the CPP-like property of this domain. 76 Ly Porosk et al 72 used 2 schemes to design peptides. As shown in Figure 3A, they added the mouse prion protein-derived peptide PrP23−28 to the signal sequence of the protein, forming a chimeric peptide.…”

“…Reproduced with permission. Copyright 2023, Ly Porosk et al (B) The TAT-NTS peptide specifically blocked the interaction of ANXA1 with importin β and inhibited the nuclear translocation of ANXA1. Reproduced with permission.…”