T14, a 14mer peptide derived from the C-terminus of acetylcholinesterase (AChE) is a signalling molecule that could drive neurodegeneration via the alpha 7 nicotinic acetylcholine receptor. Its levels increase as Alzheimer’s pathology progresses; however, a cyclic variant of the compound, NBP14, can block the effects of the endogenous linear counterpart in-vitro, ex vivo, and in vivo. Here, we explore the antagonistic potential of two 6mer peptides, NBP6A and NBP6B. These are smaller linear versions of NBP14, designed to be more effective by modifying the amino acid residues to enhance receptor blockade alongside other relevant solubility parameters. The peptides were tested in-vitro in PC12 cells on three parameters, calcium influx, cell viability, and AChE release, and ex vivo using voltage sensitive dye imaging (VSDI) in rat brain slices. Neither NBP6A nor NBP6B applied alone had any effect. In PC12 cells, NBP6B was identified as the more potent molecule since it demonstrated more effective blockade of T14 action on calcium influx, cell viability, and AChE release. NBP6B was then further evaluated using VSDI, where it proved twice as potent as NBP14 in blocking the action of T14. The improved effect of NBP6B in blocking the actions of T14, combined with its smaller size suggests that this variant could have even greater therapeutic potential than its original cyclic compound, for treating neurodegenerative disorders.

T14 是一种源自乙酰胆碱酯酶 (AChE) C 末端的 14 聚体肽，是一种信号分子，可通过 α7 烟碱乙酰胆碱受体驱动神经退行性变。随着阿尔茨海默病的病理进展，其水平会增加；然而，该化合物的环状变体 NBP14 可以在体外、离体和体内阻断内源性线性对应物的作用。在这里，我们探索了两种 6mer 肽 NBP6A 和 NBP6B 的拮抗潜力。这些是 NBP14 的较小线性版本，旨在通过修饰氨基酸残基以增强受体阻断以及其他相关溶解度参数来更有效。这些肽在体外 PC12 细胞中测试了三个参数：钙流入、细胞活力和乙酰胆碱酯酶释放，并在大鼠脑切片中使用电压敏感染料成像 (VSDI) 进行离体测试。单独应用NBP6A和NBP6B都没有任何效果。在 PC12 细胞中，NBP6B 被认为是更有效的分子，因为它能更有效地阻断 T14 对钙流入、细胞活力和 AChE 释放的作用。然后使用 VSDI 进一步评估 NBP6B，结果证明它在阻断 T14 作用方面的效力是 NBP14 的两倍。 NBP6B 在阻断 T14 作用方面的效果得到改善，加上其较小的尺寸，表明该变体可能比其原始环状化合物具有更大的治疗潜力，用于治疗神经退行性疾病。