Design of cyclic RGD-conjugated Aib-containing amphipathic helical peptides for targeted delivery of small interfering RNA. Issue 18 (15th September 2016)

• Record Type: Journal Article
• Authors: Wada, Shun-ichi; Iwata, Masashi; Ozaki, Yuka; Ozaki, Takashi; Hayashi, Junsuke; Urata, Hidehito
• Is Part Of: Bioorganic & medicinal chemistry. Volume 24:Issue 18(2016)
• Page Start: 4478
• Page End: 4485
• Publication Date: 2016-09-15
• Subjects: Amphipathic helical peptide -- MAP(Aib) -- α-Aminoisobutyric acid (Aib) -- Cell-penetrating peptide (CPP) -- RGD -- Targeted delivery -- siRNA; Bioorganic chemistry -- Periodicals; Pharmaceutical chemistry -- Periodicals; Biochemistry -- Periodicals; Chemistry, Clinical -- Periodicals; Chemistry, Organic -- Periodicals; Chimie bio-organique -- Périodiques; Chimie pharmaceutique -- Périodiques; 615.19
• DOI: 10.1016/j.bmc.2016.07.040
• Languages: English
• ISSNs: 0968-0896

Abstract

Graphical abstract: Abstract: To achieve the targeted delivery of siRNA, five conjugates of Aib-containing amphipathic helical peptides with mono-, di-, and trivalent cRGDfC [cyclo(-Arg-Gly-Asp-d -Phe-Cys-)], which is known to bind to αV β3 integrin, at several positions of the amphipathic helical peptide were designed and synthesized. Among the five conjugates, the monovalent cRGDfC conjugating at position 20 of the amino acid sequence of the helical peptide through the formation of a disulfide bond (PI ) and the divalent cRGDfC conjugating at positions 2 and 14 of the amino acid sequence of the helical peptide through the formation of disulfide bonds (PIII ) significantly enhanced the delivery of fluorescence-labeled siRNA into A549 cells as the peptide/siRNA complex formed by electrostatic interaction. The cellular uptake of thePI /siRNA complex was mediated by both endocytic and non-endocytic pathways, whereas that of thePIII /siRNA complex was enabled by endocytosis. Furthermore, the cellular uptake of thePI /siRNA complex might involve specific interactions of the RGD group with the αV β3 integrin receptor. Next, the RNAi effect of the peptide/siRNA complex on luciferase expression in A549-Luc cells was examined. Luciferase expression was significantly decreased in the presence of the complex at the concentration of 1.0 μMPI /10 nM siRNA. In contrast, thePIII /siRNA complex did not show the RNAi effect under the same conditions. However, extending the incubation time led to the suppression of the luciferase expression in the presence of thePIII /siRNA complex. Considering that the cellular uptake of thePIII /siRNA complex is mediated by the endocytic pathway, the release of siRNA from the endosome into the cytosol might require a long time. We present herein a useful and unique tool for the delivery of siRNA.