Villagomez Rodrigo, Hatti-Kaul Rajni, Sterner Olov, Almanza Giovanna, Linares-Pastén Javier A
Centre for Analysis and Synthesis, Lund University, P.O. Box 124, 221 00 Lund, Sweden; Instituto de Investigaciones Químicas, Facultad de Ciencias Puras y Naturales, Universidad Mayor de San Andrés, P.O. Box 303 La Paz, Bolivia.
Biotechnology, Dept. of Chemistry, Lund University, P.O. Box 124, SE-22 100 Lund, Sweden.
PLoS One. 2015 Jan 23;10(1):e0115819. doi: 10.1371/journal.pone.0115819. eCollection 2015.
The nuclear factor κB (NF-κB) is a promising target for drug discovery. NF-κB is a heterodimeric complex of RelA and p50 subunits that interact with the DNA, regulating the expression of several genes; its dysregulation can trigger diverse diseases including inflammation, immunodeficiency, and cancer. There is some experimental evidence, based on whole cells studies, that natural sesquiterpene lactones (Sls) can inhibit the interaction of NF-κB with DNA, by alkylating the RelA subunit via a Michael addition. In the present work, 28 natural and semisynthetic pseudoguianolides were screened as potential inhibitors of NF-κB in a biochemical assay that was designed using pure NF-κB heterodimer, pseudoguianolides and a ~1000 bp palindromic DNA fragment harboring two NF-κB recognition sequences. By comparing the relative amount of free DNA fragment to the NF-κB - DNA complex, in a routine agarose gel electrophoresis, the destabilizing effect of a compound on the complex is estimated. The results of the assay and the following structure-activity relationship study, allowed the identification of several relevant structural features in the pseudoguaianolide skeleton, which are necessary to enhance the dissociating capacity of NF-κB-DNA complex. The most active compounds are substituted at C-3 (α-carbonyl), in addition to having the α-methylene-γ-lactone moiety which is essential for the alkylation of RelA.
核因子κB（NF-κB）是药物研发中一个很有前景的靶点。NF-κB是由RelA和p50亚基组成的异源二聚体复合物，它与DNA相互作用，调控多个基因的表达；其失调会引发多种疾病，包括炎症、免疫缺陷和癌症。基于全细胞研究有一些实验证据表明，天然倍半萜内酯（SLs）可以通过迈克尔加成使RelA亚基烷基化，从而抑制NF-κB与DNA的相互作用。在本研究中，在一项生化检测中筛选了28种天然和半合成的伪愈创木内酯作为NF-κB的潜在抑制剂，该检测使用了纯NF-κB异源二聚体、伪愈创木内酯和一个含有两个NF-κB识别序列的约1000 bp回文DNA片段。通过在常规琼脂糖凝胶电泳中比较游离DNA片段与NF-κB - DNA复合物的相对量，估算化合物对复合物的去稳定作用。检测结果以及后续的构效关系研究，使得能够确定伪愈创木内酯骨架中的几个相关结构特征，这些特征对于增强NF-κB-DNA复合物的解离能力是必要的。除了具有对RelA烷基化至关重要的α-亚甲基-γ-内酯部分外，活性最高的化合物在C-3（α-羰基）处有取代。
