School of Biotechnology and State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.
Target Oncol. 2014 Jun;9(2):163-70. doi: 10.1007/s11523-013-0282-9. Epub 2013 Jun 6.
Therapeutic peptides have been proven useful for treating various diseases. However, it is difficult for therapeutic peptides to reach their target sites with an effective concentration due to inefficient intracellular delivery. Although Tat transduction peptide is a promising tool to deliver therapeutic peptides into cells, the entrapment within endosomes and the nuclear localization of Tat transduction peptide severely limited the biological effects of Tat-linked cargos. In this study, we designed a novel peptide delivering system, Tat-INF7-ubiquitin (TIU), which consisted of Tat transduction peptide, endosomal escape enhancer peptide INF7, and ubiquitin protein. We found that the TIU system was able to efficiently deliver the mCherry fluorescent proteins and the apoptosis-inducing Bak BH3 peptide into the cytosol. The Bak BH3 peptide transported into the cells by the TIU system increased the apoptotic rate to 46.15 ± 4.86% (p < 0.001) in A549 cells, while Tat-BH3 could result in only 20.45 ± 2.89%. These results demonstrated that the TIU system could enhance the effects of therapeutic peptides by facilitating the transmembrane delivery of peptides into the cells and the escape of target proteins from the endosome efficiently.
治疗性肽已被证明可用于治疗各种疾病。然而，由于细胞内递药效率低下，治疗性肽难以达到有效浓度的靶位。虽然 Tat 转导肽是将治疗性肽递送入细胞的一种很有前途的工具，但 Tat 转导肽被内体捕获和核定位严重限制了 Tat 连接载体的生物学效应。在本研究中，我们设计了一种新型的肽递药系统，Tat-INF7-泛素（TIU），它由 Tat 转导肽、内体逃逸增强肽 INF7 和泛素蛋白组成。我们发现，TIU 系统能够有效地将 mCherry 荧光蛋白和凋亡诱导 Bak BH3 肽递送入细胞质。由 TIU 系统转运入细胞的 Bak BH3 肽可将 A549 细胞的凋亡率提高至 46.15±4.86%（p<0.001），而 Tat-BH3 仅能达到 20.45±2.89%。这些结果表明，TIU 系统可通过促进肽的跨膜递送入细胞和靶蛋白从内体有效逃逸来增强治疗性肽的作用。
