The pharmacological effects of antisense and siRNA oligonucleotides are hindered by the tendency of these molecules to become entrapped in endomembrane compartments thus failing to reach their targets in the cytosol or nucleus. We have previously used high throughput screening to identify small molecules that enhance the escape of oligonucleotides from intracellular membrane compartments and have termed such molecules OECs (oligonucleotide enhancing compounds). Here, we report on the structure–activity relationships of a family of OECs that are analogs of a hit that emerged from our original screen. These studies demonstrate key roles for the lipophilic aromatic groups, the tertiary nitrogen, and the carbamate moiety of the parent compound. We have also investigated the intracellular site of action of the OECs and have shown that activity is due to the release of oligonucleotides from intermediate endosomal compartments rather than from early endosomes or from highly acidic downstream compartments. At high concentrations of OECs toxicity occurs in a manner that is independent of caspases or of lysosomal cathepsins but instead involves increased plasma membrane permeability. Thus, in addition to describing specific characteristics of this family of OECs, the current study provides insights into basic mechanisms of oligonucleotide trafficking and their implications for oligonucleotide delivery.

中文翻译：

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增强寡核苷酸递送的小分子的构效关系和细胞作用机制

反义寡核苷酸和 siRNA 寡核苷酸的药理作用受到这些分子被困在内膜区室中的趋势的阻碍，因此无法达到它们在细胞质或细胞核中的目标。我们之前使用高通量筛选来鉴定增强寡核苷酸从细胞内膜隔室逃逸的小分子，并将此类分子称为 OEC（寡核苷酸增强化合物）。在这里，我们报告了一个 OEC 家族的结构-活性关系，这些 OEC 类似于从我们的原始屏幕出现的命中。这些研究证明了亲脂芳香基团、叔氮和母体化合物的氨基甲酸酯部分的关键作用。我们还研究了 OEC 的细胞内作用位点，并表明其活性是由于寡核苷酸从中间内体区室而不是早期内体或高酸性下游区室释放。在高浓度的 OEC 下，毒性以不依赖于半胱天冬酶或溶酶体组织蛋白酶的方式发生，而是涉及质膜通透性的增加。因此，除了描述这个 OEC 家族的具体特征外，目前的研究还提供了对寡核苷酸运输的基本机制及其对寡核苷酸递送的影响的见解。在高浓度的 OEC 下，毒性以不依赖于半胱天冬酶或溶酶体组织蛋白酶的方式发生，而是涉及质膜通透性的增加。因此，除了描述这个 OEC 家族的具体特征外，目前的研究还提供了对寡核苷酸运输的基本机制及其对寡核苷酸递送的影响的见解。在高浓度的 OEC 下，毒性以不依赖于半胱天冬酶或溶酶体组织蛋白酶的方式发生，而是涉及质膜通透性的增加。因此，除了描述这个 OEC 家族的具体特征外，目前的研究还提供了对寡核苷酸运输的基本机制及其对寡核苷酸递送的影响的见解。