New activators of eIF2α Kinase Heme-Regulated Inhibitor (HRI) with improved biophysical properties.
New activators of eIF2α Kinase Heme-Regulated Inhibitor (HRI) with improved biophysical properties.
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eIF2α 激酶血红素调节抑制剂 (HRI) 的新型激活剂，具有改进的生物物理特性。
DOI：
10.1016/j.ejmech.2019.111973
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发表时间：
2020
影响因子：
6.7
通讯作者：
Aktas,BertalH
中科院分区：
文献类型：
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作者：
Zhang,Qingwen;Du,Ronghui;ReisMonteiroDosSantos,GuilhermeRodrigo;Yefidoff-Freedman,Revital;Bohm,Andrew;Halperin,Jose;Chorev,Michael;Aktas,BertalH
血红素调节抑制剂（HRI）是一种真核生物翻译起始因子2 α（eIF 2 α）激酶，在网织红细胞蛋白质合成与血红素利用率的偶联以及所有细胞对各种环境应激的适应中起着至关重要的作用。HRI改变了包括β-地中海贫血在内的几种血红蛋白错误折叠疾病的严重程度。HRI的小分子活化剂对于研究该激酶的正常和病理生物学以及治疗HRI活化或eIF 2 α磷酸化可能有益的各种人类疾病至关重要。我们先前报道了1-（（1，4-反式）-4-芳氧基环己基）-3-芳基脲（cHAU）作为特异性HRI激活剂的发展，并证明了它们作为研究HRI生物学的分子探针和作为治疗各种人类疾病的先导化合物的潜力。为了开发更多的类药cHAU用于体内研究和药物开发，并扩大化学空间，我们进行了生物测定指导的构效关系研究，用各种4-6元环取代环己基环，并探索N-苯环上的进一步取代。我们在替代eIF 2 α磷酸化和细胞增殖试验中检测了所有类似物，并在二级机制试验中检测了一部分类似物，包括内源性eIF 2 α磷酸化和下游效应物C/EBP同源蛋白（CHOP）的表达。最后，我们通过测试这些化合物在用靶向HRI的siRNA转染的细胞或模拟物中的抗增殖活性来确定这些化合物对HRI的特异性。这些化合物显著改善了cLogP而没有效力损失，使其成为开发有效和特异性激活HRI的研究性新药的先导优化的优秀候选物。
Heme-regulated inhibitor (HRI), a eukaryotic translation initiation factor 2 alpha (eIF2α) kinase, is critically important for coupling protein synthesis to heme availability in reticulocytes and adaptation to various environmental stressors in all cells. HRI modifies the severity of several hemoglobin misfolding disorders including β-thalassemia. Small molecule activators of HRI are essential for studying normal- and patho-biology of this kinase as well as for the treatment of various human disorders for which activation of HRI or phosphorylation of eIF2α may be beneficial. We previously reported development of 1-((1,4-trans)-4-aryloxycyclohexyl)-3-arylureas (cHAUs) as specific HRI activators and demonstrated their potential as molecular probes for studying HRI biology and as lead compounds for treatment of various human disorders. To develop more druglike cHAUs forin vivostudies and drug development and to expand the chemical space, we undertook bioassay guided structure–activity relationship studies replacing cyclohexyl ring with various 4-6-membered rings and explored further substitutions on theN-phenyl ring. We tested all analogs in the surrogate eIF2α phosphorylation and cell proliferation assays, and a subset of analogs in secondary mechanistic assays that included endogenous eIF2α phosphorylation and expression of C/EBP homologous protein (CHOP), a downstream effector. Finally, we determined specificity of these compounds for HRI by testing their anti-proliferative activity in cells transfected with siRNA targeting HRI or mock. These compounds have significantly improved cLogPs with no loss of potencies, making them excellent candidates for lead optimization for development of investigational new drugs that potently and specifically activate HRI.