octaarginine and betadex

Niemann-Pick disease type C (NPC) is an autosomal recessive lysosomal storage disorder, which is an inherited disease characterized by the accumulation of unesterified cholesterol in endolysosomes. Recently, 2-hydroxypropyl-β-cyclodextrin (HP-β-CyD) has been used for the treatment of NPC, and ameliorated a hepatosplenomegaly in the patients. However, to obtain the treatment efficacy, a high dose of HP-β-CyD was necessary. Therefore, the decrease in dose by using active intracellular delivery system of β-CyD to NPC cells is expected. In this study, to efficiently deliver β-CyD to NPC-like cells, we newly synthesized octaarginine (R8)-appended β-CyD with a spacer of γ-aminobutyric acid (R8-β-CyD) and evaluated its cytotoxicity, intracellular distribution, endocytosis pathway and cholesterol-lowering effect in Npc1-trap-Chinese hamster ovary (CHO) cells, cholesterol-accumulated cells through the impairment of NPC1 function. R8-β-CyD did not show cytotoxicity in the cells. In addition, Alexa568-labeled R8-β-CyD was actively internalized into Npc1-trap-CHO cells, possibly through micropinocytosis. Notably, R8-β-CyD significantly decreased intracellular cholesterol content compared with HP-β-CyD. These results suggest that R8-β-CyD may be a promising therapeutic agent for ameliorating cholesterol accumulation in NPC.

Topics: Animals; beta-Cyclodextrins; CHO Cells; Cholesterol; Cricetinae; Cricetulus; Endocytosis; gamma-Aminobutyric Acid; Niemann-Pick Disease, Type C; Oligopeptides

This paper describes the synthesis, structural characterization and cellular uptake of a supramolecular 1 : 2 inclusion complex of meso-tetraphenylporphyrin having an octaarginine peptide chain (R8-TPP) and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TMe-β-CD). R8-TPP was synthesized by 2 approaches: (1) on-resin conjugation of the N-terminal of octaarginine with 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin, followed by cleavage from the resin, and (2) Michael addition reaction between 5-[4-(3-maleimidopropylamido)phenyl]-10,15,20-triphenylporphyrin and cysteine-octaarginine peptide (Cys-Arg8). The R8-TPP obtained from both the approaches formed stable inclusion complexes with TMe-β-CD by which non-substituted phenyl groups at the 10- and 20-positions were included to form trans-type 1 : 2 inclusion complexes. The complexation prevented the self-aggregation of R8-TPP, which resulted in the solubilisation of R8-TPP in aqueous media. A cellular uptake study using HeLa cells showed that R8-TPP complexed with TMe-β-CD in a serum-free medium was efficiently taken up by the cells and uniformly dispersed in the cytosol. In the serum-containing medium, the R8-TPP-TMe-β-CD complex dissociated, and the serum protein bound R8-TPP. The R8-TPP-protein complex was localized in the endosomes of the cells. The cytosol-dispersed R8-TPP showed a higher photo-induced cytotoxicity than its endosome-trapped counterpart.

Topics: beta-Cyclodextrins; Cell Death; Cell Survival; Dose-Response Relationship, Drug; HeLa Cells; Humans; Methylation; Molecular Structure; Oligopeptides; Porphyrins; Structure-Activity Relationship