Key Laboratory of Structure-Based Drug Design and Discovery (Shenyang Pharmaceutical University), Ministry of Education, Shenyang 110016, PR China; Institute of Drug Research in Medicine Capital of China, Benxi 117000, PR China.
Department of Pharmacy, Liaoning Vocational College of Medicine, Shenyang 110101, PR China.
Bioorg Chem. 2020 Jan;94:103417. doi: 10.1016/j.bioorg.2019.103417. Epub 2019 Nov 11.
In previous work, the target of asperphenamate as a natural product was successfully determined as cathepsin by the natural product consensus pharmacophore strategy. In order to develop accurate SAR (structure-activity relationship) of asperphenamate-type cathepsin inhibitor, we chose several novel analogs with heterocyclic moiety to perform further study. The molecular simulation showed that 4-pyridyl derivative 3 with the greatest cathepsin inhibitory activity presented new interaction modes with protein utilizing its B-ring moiety. And then molecular dynamics (MD) simulation further revealed that 3 and cathepsin kept stable interaction in the binding site, which validated the molecular docking results. In view that cathepsins play an important role in fibrosis and some cathepsin inhibitors display the therapeutic ability for fibrosis, we investigated the anti-fibrotic effect of 3in vitro and in vivo. The results indicated that 3 displayed the strongest inhibitory effect on the formation of α-SMA and collagen I as the protein markers of fibrosis among all tested derivatives. Further in vivo assay confirmed that 3 indeed showed significant inhibitory ability against pulmonary fibrosis by the method of H&E and Masson staining as well as immunohistochemical staining for characteristic α-SMA proteins.
在之前的工作中，我们成功地通过天然产物共识药效团策略将 Asperphenamate 确定为组织蛋白酶的天然产物靶标。为了进一步研究 Asperphenamate 型组织蛋白酶抑制剂的准确构效关系（SAR），我们选择了几种具有杂环部分的新型类似物。分子模拟表明，具有最大组织蛋白酶抑制活性的 4-吡啶基衍生物 3 利用其 B 环部分呈现与蛋白质的新相互作用模式。然后分子动力学（MD）模拟进一步表明，3 和组织蛋白酶在结合部位保持稳定的相互作用，这验证了分子对接的结果。鉴于组织蛋白酶在纤维化中起重要作用，并且一些组织蛋白酶抑制剂显示出对纤维化的治疗能力，我们研究了 3 在体外和体内的抗纤维化作用。结果表明，在所有测试的衍生物中，3 对纤维化的蛋白标志物 α-SMA 和胶原蛋白 I 的形成表现出最强的抑制作用。进一步的体内试验通过 H&E 和 Masson 染色以及特征性 α-SMA 蛋白的免疫组织化学染色证实，3 确实对肺纤维化表现出显著的抑制能力。
