西红花酸对晚期糖基化终产物诱导牛血管内皮细胞E-选择素表达的抑制作用

目的：研究西红花酸（crocetin）对晚期糖基化终产物（advanced glycation end products,AGEs）诱导牛主动脉血管内皮细胞（bovine Endothelial cells,BECs）E-选择素（E-selectin）表达的抑制作用。方法：分离纯化新生牛全血的中性粒细胞与单核细胞,用虎红染色法测定西红花酸对牛单核细胞/中性粒细胞与BECs黏附的影响,Cell-based ELISA法和sABC免疫细胞化学法测定E-选择素蛋白表达变化。结果：AGEs（100μg/mL）能促进中性粒细胞和单核细胞对BECs的黏附（P〈0.01 vs control）,用西红花酸（1,0.1,0.01μmol/L）预孵内皮细胞12h后,再用AGEs作用24h,中性粒细胞和单核细胞对BECs的黏附较AGEs模型组降低,且呈剂量依赖性关系（P〈0.05或0.01）。Cell-based ELISA测定结果显示,AGEs作用4h内,BECs中的E-selectin表达水平上升,之后E-selectin表达下降,8h时,恢复接近正常水平。而西红花酸（1,0.1μmol/L）能使E-selectin表达下降。sABC免疫化学结果也证实西红花酸对AGEs诱导BECs中E-selectin表达有抑制作用。结论：西红花酸可通过抑制黏附分子E-selcetin蛋白表达,从而抑制中性粒细胞和单核细胞对内皮细胞的黏附作用,这可能是西红花酸减轻糖尿病血管病变的作用机制之一。

Inhibitory action of crocetin on the expression of E-selectin in bovine endothelial cells induced by advanced glycation end products

AIM：To study the inhibitory effect of crocetin on the expression of E-selectin in bovine endothelial cells （BECs） induced by advanced glycation end products （AGEs）. METHODS： Neutrophils and monocytes were separated and purified from the whole blood of new-born calf. The adhesion of neutrophils/ monocytes to endothelial cells was assayed by Fuhong staining method. Cell-based ELISA and sABC immunocytochemistry were adopted to analyze the expression of E-selectin. RESULTS：AGEs（100 μg/mL）could increase the adhesion of neutrophils/monocytes to endothelial cells（P0.01 vs control）. However, after pre-incubation the BECs with crocetin（1,0.1,0.01 μmol/L） for 12 h before exposure to AGEs （100 mg/mL） , the above adhesion rate decreased significantly in a dose-dependent manner（ P0.05 or 0.01 vs AGEs group）. Cell-based ELISA results demonstrated that the expression of E-selectin elevated in BECs treated by AGEs within 4 h, then decreased and regained to the normal level at 8 h, while the protein expression of E-selectin was suppressed by crocetin. sABC immunocytochemistry also confirmed that crocetin could decrease the level of E-selectin. CONCLUSION： These results demonstrate that crocetin could inhibit E-selectin over-expression in BECs exposed to AGEs and then down-regulate the adhesion of neutrophils/monocytes to endothelial cells, which is one of the possible mechanisms for crocetin to attenuate diabetic vascular complications.