XBP1-s调控UPR通路参与抗VEGF治疗脉络膜新生血管耐药机制的研究

Anti-VEGF therapy has been regarded as break-through strategies for treating choroidal neovascularization (CNV), however the problem of anti-VEGF resistance is a rising issue in daily practice. Our previous research revealed that integrinα5 can be singled out as one of the primary proteins required for CNV as a VEGF-independent pathway, which may explain why anti-VEGF monothreapy doesn't work in some cases. Recently, it was found that unfolded protein response (UPR) participated into retinal stress process to regulate of the expression of VEGF. So it was suggested that UPR pathway and integrinα5 might play a key role in the mechanism of anti-VEGF resistance. Therefore, we will investigate the expression of molecule chaperone of UPR in vitro and vivo CNV model. Then activation of VEGF/VEGFR and integrinα5 /FAK/vinculin pathway will be investigated by using UPR inhibitors and knockdown techniques to explore whether UPR is the upstream regulatory pathway involving in the anti-VEGF resistance. Lastly, as a key target molecule to regulate UPR pathway, XBP1-s will be investigated whether it plays a critical role in the anti-VEGF resistance by regulating UPR activity. Our research will help to reveal that the novel mechanism of anti-VEGF resistance, which will be helpful to develop new agents in the treatment of CNV.

抗VEGF治疗脉络膜新生血管（CNV）的耐药机制复杂且少有报道。课题组前期研究发现integrinα5能独立于VEGF通路之外单独诱导形成CNV，且不被VEGF抗体所抑制；新近发现未折叠蛋白反应（UPR）参与调控视网膜细胞损伤，介导VEGF分泌，提示integrinα5与UPR可能参与抗VEGF耐药机制。以此为基础，课题组拟在体内外CNV模型中，采用特异性抑制剂/基因沉默技术，研究UPR信号分子表达及其对VEGF/VEGFR及integrinα5 /FAK/vinculin通路表达影响，阐明UPR通路参与抗VEGF耐药的调控机制；并研究XBP1-s过表达/基因沉默时，对UPR通路调控以及对CNV形成干预作用及机制，阐明XBP1-s在抗VEGF耐药机制中调控UPR通路的"分子开关"作用。课题完成将为明确抗VEGF耐药分子机制提供理论依据，为提高临床疗效、或研发新型抗CNV药物提供新思路。

抗 VEGF 治疗脉络膜新生血管（CNV）的耐药机制复杂且少有报道。课题组在前期研究基础上，在本课题中，建立体外A2E联合蓝光致视网膜色素上皮细胞（RPE）损伤模型从而模拟年龄相关性黄斑变性（AMD）病理改变，观察到未折叠蛋白反应参与调控了RPE细胞损伤，UPR关键蛋白GRP78和XBP1s在损伤过程中有表达升高。STF-083010干预XBP1s后，RPE细胞凋亡增加、而坏死性凋亡蛋白表达减少，提示UPR通路关键转录因子XBP1s参与了视网膜细胞损伤的过程，其可能是调控RPE细胞死亡结局的重要分子开关。同时，建立体内大鼠激光诱导的CNV模型中，进一步研究UPR相关整合素α5β1在CNV新生血管形成过程中的机制研究。发现大鼠激光诱导CNV模型中，整合素α5β1表达升高，运用抑制剂抑制整合素α5表达后，CNV面积及荧光渗漏显著减少。上述研究进一步阐明了UPR中XBP1s通路和整合素α5是调节视网膜细胞损伤和新生血管形成的关键机制，本课题研究的完成丰富和完善了未折叠蛋白反应和整合素家族参与调控视网膜细胞损伤和CNV形成的相关理论，具有一定的创新意义，为更好地保护RPE细胞、延缓脉络膜新生血管提供了新的理论依据，也为临床延缓干性、湿性AMD的发展提供了新的治理思路。