论文部分内容阅读
目的研究多巴胺D_4受体对高糖诱导的血管内皮细胞损伤的保护作用及相关机制。方法构建链脲佐菌素(STZ)诱导的糖尿病大鼠模型,Western blot法检测内皮组织D_4受体表达的变化。以体外培养的人脐静脉内皮细胞(HUVEC)为靶细胞,测定在高糖(33 mmol/L)刺激下细胞的活力,同时检测D_4受体表达变化;用高糖刺激HUVEC后,在D_4受体激动剂PD168077(10-7 mol/L)、磷脂酰肌醇3激酶(PI3K)抑制剂LY294002(5×10~(-5 )mol/L)和内皮型一氧化氮合酶(eNOS)抑制剂左旋硝基精氨酸甲酯(l-NAME)(10-4 mol/L)分别作用的情况下,检测HUVEC细胞活力水平的变化,并检测细胞中蛋白激酶B(Akt)和eNOS的磷酸化水平以及总的Akt和eNOS表达水平。结果 D_4受体在糖尿病大鼠胸主动脉内皮组织和HUVEC的表达下降(均P<0.05)。高糖条件下,HUVEC的细胞活力下降(P<0.05);与高糖组比较,加入PD168077后HUVEC的细胞活力增加(P<0.05)。在LY294002和l-NAME的作用下,HUVEC的细胞活力下降(P<0.05);同时,p-Akt[高糖+LY294002+PD168077组(0.59±0.09),高糖+l-NAME+PD168077组(0.62±0.07),高糖+PD168077组(1.44±0.07),P<0.05]和p-eNOS[高糖+LY294002+PD168077组(0.62±0.05),高糖+l-NAME+PD168077组(0.66±0.08),高糖+PD168077组(1.44±0.08),P<0.05]的蛋白表达水平也降低。结论多巴胺D_4受体可以改善高糖诱导的HUVEC的损伤,该作用可能与PI3K/Akt/eNOS信号通路相关。
Objective To study the protective effect and mechanism of dopamine D_4 receptor on high glucose-induced endothelial cell injury. Methods Streptozotocin (STZ) -induced diabetic rat model was constructed, and the changes of D4 receptor expression in endothelial cells were detected by Western blot. In vitro cultured human umbilical vein endothelial cells (HUVECs) were used as target cells. The viability of cells under high glucose (33 mmol / L) stimulation was measured, and the changes of D4 receptor expression were detected. HUVEC stimulated by high glucose The inhibitory effect of PD168077 (10-7 mol / L), PI3K inhibitor LY294002 (5 × 10 -5 mol / L) and endothelial nitric oxide synthase (eNOS) (L-NAME) (10-4 mol / L) were used to detect the changes of cell viability in HUVECs and the phosphorylation of protein kinase B (Akt) and eNOS As well as the total Akt and eNOS expression levels. Results The expression of D_4 receptor in the thoracic aorta and HUVEC decreased in diabetic rats (all P <0.05). The cell viability of HUVEC decreased in high glucose (P <0.05). Compared with high glucose group, the cell viability of HUVEC increased after addition of PD168077 (P <0.05). The cell viability of HUVEC was decreased by LY294002 and l-NAME (P <0.05), while p-Akt [high glucose + LY294002 + PD168077 group (0.59 ± 0.09), high glucose + l-NAME + PD168077 group 0.62 ± 0.07), high glucose + PD168077 group (1.44 ± 0.07), P <0.05] and p-eNOS [high glucose + LY294002 + PD168077 group (0.62 ± 0.05) 0.08), high glucose + PD168077 group (1.44 ± 0.08), P <0.05]. Conclusion Dopamine D 4 receptor can improve HUVEC induced by high glucose, which may be related to the PI3K / Akt / eNOS signaling pathway.