Antisense oligonucleotides modified with phosphorothioate linkages (PS-ASOs) can enter cells via endocytic pathways and must escape from membraned organelles to reach target RNAs. We recently found that membrane destabilization induced by different lipid species contributes to PS-ASO release from late endosomes (LEs). In this study, we characterized intracellular uptake, trafficking, and activities of PS-ASOs conjugated with different lipid species. We found that palmitic acid-, tocopherol-, and cholesterol-conjugated PS-ASOs have increased protein binding and enhanced intracellular uptake compared to unconjugated PS-ASOs. Similar to the parental PS-ASO, the lipid-conjugated PS-ASOs traffic from early to LEs without incorporation into lipid droplets. Unlike parental PS-ASOs, the lipid-conjugated PS-ASOs tend to remain associated with plasma or endosomal membranes, and this appears to influence their release from endosomes. The lipid-conjugated PS-ASOs were released more rapidly than parental PS-ASO. These results suggest that lipid conjugation enhances the interactions of PS-ASOs with proteins or membranes, in turn facilitating intracellular trafficking and endosomal release.

中文翻译：

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脂质缀合物增强了反义寡核苷酸向细胞内的内体释放。

用硫代磷酸酯键（PS-ASO）修饰的反义寡核苷酸可以通过内吞途径进入细胞，必须从膜细胞器逃逸才能到达靶RNA。我们最近发现，由不同脂质种类引起的膜不稳定会导致PS-ASO从晚期内体（LEs）释放。在这项研究中，我们表征了与不同脂质物种结合的PS-ASO的细胞内摄取，运输和活性。我们发现，与未结合的PS-ASO相比，棕榈酸，生育酚和胆固醇结合的PS-ASO具有增加的蛋白质结合力和增强的细胞内摄取。与亲代PS-ASO相似，脂质结合的PS-ASO从早期运输到LE，而没有掺入脂质液滴。与父母的PS-ASO不同，脂质缀合的PS-ASO倾向于保持与质膜或内体膜结合，这似乎影响它们从内体的释放。脂质缀合的PS-ASO比亲代PS-ASO释放更快。这些结果表明脂质结合增强了PS-ASO与蛋白质或膜的相互作用，进而促进了细胞内运输和内体释放。