淀粉样β(Aβ)肽沉积被认为是阿尔茨海默病(AD)的主要病因。以前,我们已经表明,含锌的中性酞菁(Zn-Pc)抑制Aβ原纤维的形成。
本研究的目的是研究含阳离子镓的Pc(GaCl-Pc)对Aβ原纤维形成过程的影响。
通过在原纤维形成缓冲液中孵育合成的Aβ肽来诱导Aβ原纤维形成,并通过ThT荧光测定法评估原纤维的量。GaCl-Pc剂量依赖性地抑制Aβ1-40和Aβ1-42原纤维的形成。它主要抑制Aβ1-42原纤维形成动力学的伸长阶段,但不是滞后阶段。Westernblotting结果表明,它没有抑制其寡聚化过程,而是增加了它。此外,GaCl-Pc在体外条件下剂量依赖性地使预制Aβ1-42原纤维不稳定,APP转基因AD模型小鼠(J20株)脑片培养物中Aβ水平降低。近红外扫描结果表明,GaCl-Pc具有与Aβ1-42结合的能力。MTT实验表明,GaCl-Pc对培养物中的神经元细胞系(A1)没有毒性,对Aβ诱导的毒性具有保护作用。此外,它剂量依赖性地降低了A1培养物中Aβ诱导的活性氧水平。
因此,我们的结果表明,GaCl-Pc降低了Aβ聚集并使预先形成的原纤维不稳定。由于阳离子分子显示出更好的穿越血脑屏障的能力,阳离子GaCl-Pc对AD的治疗具有重要意义。
Amyloid β (Aβ) peptide deposition is considered as the main cause of Alzheimer\'s disease (AD). Previously, we have shown that a Zn containing neutral phthalocyanine (Zn-Pc) inhibits Aβ fibril formation.
The objective of this study is to investigate the effects of a cationic gallium containing Pc (GaCl-Pc) on Aβ fibril formation process.
Aβ fibril formation was induced by incubating synthetic Aβ peptides in a fibril forming buffer, and the amount of fibril was evaluated by ThT fluorescence assay. GaCl-Pc dosedependently inhibited both Aβ1-40 and Aβ1-42 fibril formation. It mainly inhibited the elongation phase of Aβ1-42 fibril formation kinetics, but not the lag phase. Western blotting results showed that it did not inhibit its oligomerization process, rather increased it. Additionally, GaCl-Pc destabilized preformed Aβ1- 42 fibrils dose-dependently in vitro condition, and decreased Aβ levels in the brain slice culture of APP transgenic AD model mice (J20 strain). Near-infrared scanning results showed that GaCl-Pc had the ability to bind to Aβ1-42. MTT assay demonstrated that GaCl-Pc did not have toxicity towards a neuronal cell line (A1) in culture rather, showed protective effects on Aβ-induced toxicity. Moreover, it dosedependently decreased Aβ-induced reactive oxygen species levels in A1 culture.
Thus, our result demonstrated that GaCl-Pc decreased Aβ aggregation and destabilized the preformed fibrils. Since cationic molecules show a better ability to cross the blood-brain barrier, cationic GaCl-Pc could be important for the therapy of AD.