i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
IBMC-Instituto de Biologia Molecular e Celular, Parasite Disease Group, Porto, Portugal.
PLoS Negl Trop Dis. 2018 Jan 22;12(1):e0006180. doi: 10.1371/journal.pntd.0006180. eCollection 2018 Jan.
Chagas disease remains one of the most neglected diseases in the world despite being the most important parasitic disease in Latin America. The characteristic chronic manifestation of chagasic cardiomyopathy is the region's leading cause of heart-related illness, causing significant mortality and morbidity. Due to the limited available therapeutic options, new drugs are urgently needed to control the disease. Sirtuins, also called Silent information regulator 2 (Sir2) proteins have long been suggested as interesting targets to treat different diseases, including parasitic infections. Recent studies on Trypanosoma cruzi sirtuins have hinted at the possibility to exploit these enzymes as a possible drug targets. In the present work, the T. cruzi Sir2 related protein 1 (TcSir2rp1) is genetically validated as a drug target and biochemically characterized for its NAD+-dependent deacetylase activity and its inhibition by the classic sirtuin inhibitor nicotinamide, as well as by bisnaphthalimidopropyl (BNIP) derivatives, a class of parasite sirtuin inhibitors. BNIPs ability to inhibit TcSir2rp1, and anti-parasitic activity against T. cruzi amastigotes in vitro were investigated. The compound BNIP Spermidine (BNIPSpd) (9), was found to be the most potent inhibitor of TcSir2rp1. Moreover, this compound showed altered trypanocidal activity against TcSir2rp1 overexpressing epimastigotes and anti-parasitic activity similar to the reference drug benznidazole against the medically important amastigotes, while having the highest selectivity index amongst the compounds tested. Unfortunately, BNIPSpd failed to treat a mouse model of Chagas disease, possibly due to its pharmacokinetic profile. Medicinal chemistry modifications of the compound, as well as alternative formulations may improve activity and pharmacokinetics in the future. Additionally, an initial TcSIR2rp1 model in complex with p53 peptide substrate was obtained from low resolution X-ray data (3.5 Å) to gain insight into the potential specificity of the interaction with the BNIP compounds. In conclusion, the search for TcSir2rp1 specific inhibitors may represent a valuable strategy for drug discovery against T. cruzi.
恰加斯病仍然是世界上最被忽视的疾病之一，尽管它是拉丁美洲最重要的寄生虫病。克氏锥虫性心肌病的特征性慢性表现是该地区导致与心脏相关疾病的主要原因，造成了重大的死亡率和发病率。由于可用的治疗选择有限，迫切需要新的药物来控制这种疾病。沉默信息调节因子 2（Sir2）蛋白，也称为沉默信息调节因子 2 蛋白，长期以来一直被认为是治疗包括寄生虫感染在内的各种疾病的有趣靶点。最近对克氏锥虫沉默信息调节因子 2 蛋白的研究表明，这些酶可能被用作潜在的药物靶点。在本工作中，克氏锥虫 Sir2 相关蛋白 1（TcSir2rp1）通过遗传验证作为药物靶点，并对其 NAD+依赖性去乙酰化酶活性以及经典沉默信息调节因子抑制剂烟酰胺、双萘甲酰基丙二酰胺（BNIP）衍生物进行了生化表征，这是一类寄生虫沉默信息调节因子抑制剂。研究了 BNIP 抑制 TcSir2rp1 的能力以及对体外克氏锥虫无鞭毛体的抗寄生虫活性。发现化合物 BNIP spermidine（BNIPSpd）（9）是 TcSir2rp1 的最强抑制剂。此外，该化合物对 TcSir2rp1 过表达的滋养体表现出改变的杀锥虫活性，并且对医学上重要的无鞭毛体的抗寄生虫活性与参考药物苯并硝唑相似，而在测试的化合物中具有最高的选择性指数。不幸的是，BNIPSpd 未能治疗恰加斯病的小鼠模型，可能是由于其药代动力学特征。化合物的药物化学修饰以及替代配方可能会在未来提高活性和药代动力学。此外，还从低分辨率 X 射线数据（3.5 Å）获得了与 p53 肽底物复合物的初始 TcSIR2rp1 模型，以深入了解与 BNIP 化合物相互作用的潜在特异性。总之，寻找 TcSir2rp1 特异性抑制剂可能是针对 T. cruzi 的药物发现的有价值策略。
