未折叠蛋白质应答(UPR)是对内质网(ER)特异性的应激反应。未折叠(或错误折叠)蛋白在内质网腔内积累后,UPR被激活,通过增加伴侣的合成恢复蛋白折叠能力。此外,UPR还增强未折叠蛋白质的降解并减少整体蛋白质合成以减轻未折叠蛋白质在ER中的额外积累。在这里,我们描述了一项基于细胞的超高通量筛查(uHTS)活动,该活动在细胞和体内疾病模型中鉴定出一种可调节UPR和ER应激的小分子.使用与Cypridina荧光素酶(CLuc)融合的去唾液酸糖蛋白受体1(ASGR)作为折叠能力的报告测定,我们已经筛选了一百万个小分子文库,并鉴定了APC655作为蛋白质折叠的有效激活剂,这似乎是通过促进伴侣表达来发挥作用的。此外,APC655在thapsigargin或细胞因子诱导的ER应激条件下改善胰腺β细胞活力和胰岛素分泌。APC655在瘦素缺乏(ob/ob)小鼠模型的肝脏中也有效地保持β细胞功能和减少脂质积累。这些结果证明了一个成功的uHTS运动,确定了UPR的调节剂,这可以为许多代谢性疾病的潜在治疗开发提供新的候选者。
Unfolded protein response (UPR) is a stress response that is specific to the endoplasmic reticulum (ER). UPR is activated upon accumulation of unfolded (or misfolded) proteins in the ER\'s lumen to restore protein folding capacity by increasing the synthesis of chaperones. In addition, UPR also enhances degradation of unfolded proteins and reduces global protein synthesis to alleviate additional accumulation of unfolded proteins in the ER. Herein, we describe a cell-based ultra-high throughput screening (uHTS) campaign that identifies a small molecule that can modulate UPR and ER stress in cellular and in vivo disease models. Using asialoglycoprotein receptor 1 (ASGR) fused with Cypridina luciferase (CLuc) as reporter assay for folding capacity, we have screened a million small molecule library and identified APC655 as a potent activator of protein folding, that appears to act by promoting chaperone expression. Furthermore, APC655 improved pancreatic β cell viability and insulin secretion under ER stress conditions induced by thapsigargin or cytokines. APC655 was also effective in preserving β cell function and decreasing lipid accumulation in the liver of the leptin-deficient (ob/ob) mouse model. These results demonstrate a successful uHTS campaign that identified a modulator of UPR, which can provide a novel candidate for potential therapeutic development for a host of metabolic diseases.