Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; The State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing 100191, China.
Eur J Pharm Biopharm. 2018 Dec;133:188-199. doi: 10.1016/j.ejpb.2018.10.014. Epub 2018 Oct 22.
As a unique macromolecular permeation enhancer, thiolated polymers (thiomers), especially the preactivated thiomers, have demonstrated great merits in oral delivery of protein/peptide drugs by triggering epithelial tight junctions (TJs) opening. However, the underlying molecular mechanism remains unclear. To clarify this issue, preactivated thiomers were synthesized and their TJs opening function as well as signaling pathways on MDCK and Caco-2 cell monolayers was investigated. The results showed that preactivated thiomers could reduce TEER and increase the permeation of Na-Flu and FITC-Insulin over 2-fold and 4-fold on MDCK monolayers, respectively, indicating their huge potential as macromolecular permeation enhancers. The signaling pathway study showed that intracellular PTK Src but not FAK, involved in the TJs opening by claudin-4 disruption. Src activation was based on interaction between thiol group of thiomers and cysteine-riched Src upstream membrane receptors, EGFR and IGFR. The deep comprehension of the thiomers-mediated TJs opening mechanisms provides goodness in application of protein/peptide drugs for the oral delivery.
作为一种独特的高分子渗透增强剂，巯基化聚合物（硫醇），特别是预激活的硫醇，通过触发上皮紧密连接（TJ）的开放，在蛋白质/肽类药物的口服递送中显示出巨大的优势。然而，其潜在的分子机制尚不清楚。为了阐明这一问题，我们合成了预激活的硫醇，并在 MDCK 和 Caco-2 细胞单层上研究了它们的 TJ 开放功能及其信号通路。结果表明，预激活的硫醇可以使 MDCK 单层上的 TEER 降低，并使 Na-Flu 和 FITC-Insulin 的渗透分别增加 2 倍和 4 倍，这表明它们作为高分子渗透增强剂具有巨大的潜力。信号通路研究表明，claudin-4 破坏引起的 TJ 开放涉及细胞内 PTK Src，但不涉及 FAK。Src 的激活是基于巯基化合物与富含半胱氨酸的 Src 上游膜受体 EGFR 和 IGF1R 之间的相互作用。对硫醇介导的 TJ 开放机制的深入理解为蛋白质/肽类药物的口服递送应用提供了更多的可能性。
