Orally administered diflunisal stabilizes transthyretin against dissociation required for amyloidogenesis
Orally administered diflunisal stabilizes transthyretin against dissociation required for amyloidogenesis
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DOI：
10.1080/13506120600960882
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发表时间：
2006-12-01
影响因子：
5.5
通讯作者：
Kelly, Jeffery W.
中科院分区：
文献类型：
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作者：
Sekijima, Yoshiki;Dendle, Maria A.;Kelly, Jeffery W.
目标。限速转甲状腺素（TTR）四聚体解离和单体错误折叠使错误组装成许多聚集体形态，包括淀粉样蛋白，这一过程与淀粉样蛋白病理遗传相关，并被认为是导致淀粉样蛋白病理的原因。T119M TTR反式抑制子亚基包含在由疾病相关亚基组成的四聚体中，通过增加四聚体解离屏障改善人类淀粉样变性。双氟尼柳与TTR中99%未占用的l -甲状腺素结合位点结合也增加了四聚体解离屏障；因此，我们在健康志愿者中研究了使用双氟尼松治疗人类TTR淀粉样变的可行性。采用双氟尼柳（125、250或500 mg / bid）口服给药，每组10人，连续7天评估血清双氟尼柳浓度、双氟尼柳与TTR的结合化学计量，以及双氟尼柳对人血清中尿素和酸介导的TTR变性的TTR动力学稳定作用程度。利用上述实验确定的生理相关浓度，我们还在体外评估了脲介导的四聚体解离率和酸介导的聚集率与双氟尼柳浓度的关系。在250 mg bid组，第13次口服剂量12小时后，双氟尼醚的血清浓度为146 +/- 39 μ M，足以使TTR结合化学计量超过0.95 +/- 0.13（校正后接近1.75）。在该剂量下，双氟尼柳与TTR的结合使血清和体外尿素介导的解离和酸介导的TTR聚集至少减缓了3倍（p < 0.05），与TTR的动力学稳定一致。双氟尼拉介导的TTR动力学稳定应改善TTR淀粉样变性，前提是非甾体抗炎药的负担可以在临床上得到控制。
Objective. Rate-limiting transthyretin (TTR) tetramer dissociation and monomer misfolding enable misassembly into numerous aggregate morphologies including amyloid, a process genetically linked to and thought to cause amyloid pathology. T119M TTR trans-suppressor subunit inclusion into tetramers otherwise composed of disease-associated subunits ameliorates human amyloidosis by increasing the tetramer dissociation barrier. Diflunisal binding to the 99% unoccupied L-thyroxine binding sites in TTR also increases the tetramer dissociation barrier; hence, we investigated the feasibility of using diflunisal for the treatment of human TTR amyloidosis using healthy volunteers.Methods. Diflunisal (125, 250 or 500 mg bid) was orally administered to groups of 10 subjects for 7 days to evaluate serum diflunisal concentration, diflunisal binding stoichiometry to TTR, and the extent of diflunisal imposed TTR kinetic stabilization against urea- and acid-mediated TTR denaturation in human serum. The rates of urea-mediated tetramer dissociation and acid-mediated aggregation as a function of diflunisal concentration were also evaluated in vitro, utilizing physiologically relevant concentrations identified by the above experiments.Results. In the 250 mg bid group, 12 h after the 13th oral dose, the diflunisal serum concentration of 146 +/- 39 mu M was sufficient to afford a TTR binding stoichiometry exceeding 0.95 +/- 0.13 (approximate to 1.75 corrected). Diflunisal binding to TTR at this dose slowed urea-mediated dissociation and acid-mediated TTR aggregation at least, threefold (p < 0.05) in serum and in vitro, consistent with kinetic stabilization of TTR.Conclusion. Diflunisal-mediated kinetic stabilization of TTR should ameliorate TTR amyloidoses, provided that the nonsteroidal anti-inflammatory drug liabilities can be managed clinically.