双水杨酸酯通过抑制内质网应激缓解高脂饮食小鼠的高血糖状态

目的：研究并探讨双水杨酸酯（Salsalate,SAL）对高脂饮食喂养的小鼠血糖水平的影响。方法：高脂饮食联合0.5%双水杨酸酯共同饲养8周龄C57BL/6J雄性小鼠40天，行胰岛素耐量试验（ITT）及葡萄糖耐量试验（GTT），提取肝脏总RNA及蛋白，检测内质网应激通路（CHOP、ERDJ4、GRP78和GRP94）的基因蛋白表达水平。结果:SAL组小鼠随机血糖水平低于对照组（pP <0.05），且GTT提示糖耐量更好，但两组空腹胰岛素水平无统计学差异，且ITT提示两者胰岛素刺激后血糖变化未见明显差异；SAL组小鼠肝脏组织GRP78和GRP94的基因表达水平较对照组减低（pP<0.05），SAL组小鼠肝脏组织CHOP、ERDJ4、GRP78和GRP94的蛋白表达水平较对照组减低（pP<0.05）。结论:双水杨酸酯通过抑制内质网应激通路缓解高脂饮食小鼠的高血糖状态，且这一过程不依赖于胰岛素作用。

Salsalate alleviates hyperglycemia by inhibiting endoplasmic reticulum stress in high fat diet induced obese mice

Objective To explore the effect of salsalate on the glucose metabolism of obese mice induced with high fat diet (HFD). Methods Eight week-old male C57BL/6J mice were fed with HFD in combination with 0.5% of salsalate (SAL group, n=5) or normal saline (control group, n=5) for 40 days. The effect of salsalate on serum glucose level was examined by glucose tolerance test (GTT) and insulin tolerance test (ITT). The expressions of endoplasmic reticulumn related proteins, including CCAAT/enhancer-binding protein homologous protein (CHOP), endoplasmic reticulum-localized DnaJ 4 (ERDJ4), glucose regulated protein (GRP)78 and GRP94, were measured by qPCR and Western blotting. Results The random blood glucose level of obese mice were significantly lower in the SAL group than that in the control group (P<0.05), and GTT showed that the mice in the SAL group had better glucose tolerance. However, there was no significant difference in fasting insulin level between the two groups. ITT showed there was no difference in the change of blood glucose after insulin stimulation between the two groups. The mRNA expressions of GRP78 and GRP94 and protein expressions of CHOP, ERDJ4, GRP78 and GRP94 were significantly lower in the SAL group than those in the control group (P<0.05 or P<0.01). Conclusion Salsalate can alleviate the hyperglycemia of obese mice induced with HFD by inhibiting endoplasmic reticulum stress, and the effect is independent of the insulin secretion.