Alves Ana Catarina, Ribeiro Daniela, Horta Miguel, Lima José L F C, Nunes Cláudia, Reis Salette
UCIBIO, REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira no. 228, 4050-313 Porto, Portugal.
UCIBIO, REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira no. 228, 4050-313 Porto, Portugal
J R Soc Interface. 2017 Aug;14(133). doi: 10.1098/rsif.2017.0408.
Daunorubicin is extensively used in chemotherapy for diverse types of cancer. Over the years, evidence has suggested that the mechanisms by which daunorubicin causes cytotoxic effects are also associated with interactions at the membrane level. The aim of the present work was to study the interplay between daunorubicin and mimetic membrane models composed of different ratios of 1,2-dimyristoyl--glycero--phosphocholine (DMPC), sphingomyelin (SM) and cholesterol (Chol). Several biophysical parameters were assessed using liposomes as mimetic model membranes. Thereby, the ability of daunorubicin to partition into lipid bilayers, its apparent location within the membrane and its effect on membrane fluidity were investigated. The results showed that daunorubicin has higher affinity for lipid bilayers composed of DMPC, followed by DMPC : SM, DMPC : Chol and lastly by DMPC : SM : Chol. The addition of SM or Chol into DMPC membranes not only increases the complexity of the model membrane but also decreases its fluidity, which, in turn, reduces the amount of anticancer drug that can partition into these mimetic models. Fluorescence quenching studies suggest a broad distribution of the drug across the bilayer thickness, with a preferential location in the phospholipid tails. The gathered data support that daunorubicin permeates all types of membranes to different degrees, interacts with phospholipids through electrostatic and hydrophobic bonds and causes alterations in the biophysical properties of the bilayers, namely in membrane fluidity. In fact, a decrease in membrane fluidity can be observed in the acyl region of the phospholipids. Ultimately, such outcomes can be correlated with daunorubicin's biological action, where membrane structure and lipid composition have an important role. In fact, the results indicate that the intercalation of daunorubicin between the phospholipids can also take place in rigid domains, such as rafts that are known to be involved in different receptor processes, which are important for cellular function.
柔红霉素广泛用于多种癌症的化疗。多年来，有证据表明柔红霉素产生细胞毒性作用的机制也与膜水平的相互作用有关。本研究的目的是研究柔红霉素与由不同比例的1,2 - 二肉豆蔻酰 - sn - 甘油 - 3 - 磷酸胆碱（DMPC）、鞘磷脂（SM）和胆固醇（Chol）组成的模拟膜模型之间的相互作用。使用脂质体作为模拟模型膜评估了几个生物物理参数。由此，研究了柔红霉素分配到脂质双层中的能力、其在膜内的表观位置及其对膜流动性的影响。结果表明，柔红霉素对由DMPC组成的脂质双层具有更高的亲和力，其次是DMPC:SM、DMPC:Chol，最后是DMPC:SM:Chol。向DMPC膜中添加SM或Chol不仅增加了模型膜的复杂性，还降低了其流动性，这反过来又减少了可分配到这些模拟模型中的抗癌药物量。荧光猝灭研究表明药物在双层厚度上分布广泛，在磷脂尾部有优先定位。收集的数据支持柔红霉素以不同程度渗透所有类型的膜，通过静电和疏水键与磷脂相互作用，并导致双层生物物理性质的改变，即膜流动性的改变。事实上，在磷脂的酰基区域可以观察到膜流动性的降低。最终，这些结果可以与柔红霉素的生物学作用相关联，其中膜结构和脂质组成起着重要作用。实际上，结果表明柔红霉素在磷脂之间的嵌入也可以发生在刚性结构域中，例如已知参与不同受体过程的脂筏，这些过程对细胞功能很重要。
