As a dendritic cell-specific C-type lectin receptor, DC-SIGN plays an important role in the early stages of many viral infections, including HIV and Ebola, making it an interesting therapeutic target. It has been foun...As a dendritic cell-specific C-type lectin receptor, DC-SIGN plays an important role in the early stages of many viral infections, including HIV and Ebola, making it an interesting therapeutic target. It has been found that DC-SIGN can recognize both highly mannosylated and branched fucosylated oligosaccharides. Herein, we synthesized a new series of homo-and Man-Fuc heteroglycoclusters with diverse structures. The binding properties of these compounds to tetrameric extracellular DC-SIGN were assessed by surface plasmon resonance(SPR). Heteroglycocluster 17 b showed high DC-SIGN-binding activity(K;= 2.6 μM). The structural determinants of this high affinity of 17 b were rationalized by docking and compared with its much less potent isomer 17 a. Therefore, 17 b might serve as a base for the development of potent inhibitors of DC-SIGN-dependent viral infection.展开更多
文摘目的:探讨富含脯氨酸的酪氨酸激酶2(proline-rich tyrosine kinase 2,Pyk2)在糖尿病(diabetes mellitus,DM)小鼠中的表达和在肾小管上皮细胞的作用,以及α-硫辛酰胺(alpha-lipoamide,ALM)是否通过调控Pyk2延缓糖尿病肾病(diabetic kidney disease,DKD)肾纤维化。方法:选取8周龄野生型(wild-type,WT)小鼠和db/db小鼠各5只,正常饮食饲养至16周,Western blot检测肾组织纤维连接蛋白(fibronectin,FN)、III型胶原α1链(collagen type III alpha 1 chain,COL3A1)、Pyk2和p-Pyk2(Y402)的蛋白水平,免疫组织化学染色观察Pyk2和p-Pyk2(Y402)蛋白分布及表达情况,RT-qPCR检测Pyk2的mRNA水平。体外培养大鼠肾小管上皮细胞系NRK-52E,取对数生长期细胞予以高糖高脂(high glucose and high palmitic acid,HP)、Pyk2抑制剂PF-562271、ALM处理及转染Pyk2过表达质粒后,分为正常糖(normal glucose,NG)组、HP组、HP+PF-562271组、HP+vector组、HP+OE-Pyk2组、HP+ALM组和HP+ALM+OE-Pyk2组,每组重复3次。免疫荧光染色观察Pyk2蛋白定位及表达,Western blot检测FN、COL3A1、Pyk2和p-Pyk2(Y402)的蛋白水平,RT-qPCR检测Pyk2的mRNA水平。结果:与WT组相比,db/db组小鼠纤维化指标(FN和COL3A1)蛋白表达升高,Pyk2和p-Pyk2(Y402)主要在肾小管中表达且蛋白表达水平显著升高,Pyk2的mRNA水平显著升高(P<0.05)。与NG组比较,HP组中纤维化指标、Pyk2和p-Pyk2(Y402)蛋白水平显著升高,Pyk2的mRNA水平显著升高(P<0.05);予PF-562271处理后,与HP组比较,p-Pyk2(Y402)和纤维化指标蛋白水平显著降低,予转染Pyk2过表达质粒后,与HP+vector组比较,纤维化指标蛋白水平显著升高(P<0.05)。经ALM干预后,与HP组比较,Pyk2、p-Pyk2(Y402)及纤维化指标蛋白水平显著降低(P<0.05),与HP+ALM组比较,转染Pyk2过表达质粒后,纤维化指标的变化趋势被逆转(P<0.05)。结论:Pyk2在DM小鼠中表达升高,在肾小管上皮细胞表达可促进DKD肾纤维化进展;ALM可通过下调肾小管上皮细胞中Pyk2的表达及磷酸化延缓DKD肾纤维化进展。
基金National Natural Science Foundation of China(NSFC,Grant No.21172015)Wellcome Trust (UK,Grant No.097354/Z/11/Z)+1 种基金ML acknowledges the Research Project RVO61388963 of the Institute of Organic Chemistry and BiochemistryAcademy of Sciences of the Czech Republic,the Czech Science Foundation (Grant No.P20 8/12/G016)。
文摘As a dendritic cell-specific C-type lectin receptor, DC-SIGN plays an important role in the early stages of many viral infections, including HIV and Ebola, making it an interesting therapeutic target. It has been found that DC-SIGN can recognize both highly mannosylated and branched fucosylated oligosaccharides. Herein, we synthesized a new series of homo-and Man-Fuc heteroglycoclusters with diverse structures. The binding properties of these compounds to tetrameric extracellular DC-SIGN were assessed by surface plasmon resonance(SPR). Heteroglycocluster 17 b showed high DC-SIGN-binding activity(K;= 2.6 μM). The structural determinants of this high affinity of 17 b were rationalized by docking and compared with its much less potent isomer 17 a. Therefore, 17 b might serve as a base for the development of potent inhibitors of DC-SIGN-dependent viral infection.
