Diabetes Research Group, Department of Internal Medicine, University of Manitoba, 835-715 McDermot Ave, Winnipeg, MB R3E 3P4, Canada.
Human Nutritional Science, University of Manitoba, Winnipeg, Canada.
Inflamm Res. 2017 Sep;66(9):783-792. doi: 10.1007/s00011-017-1057-z. Epub 2017 May 26.
To determine the requirement of plasminogen activator inhibitor-1-knockout (PAI-1) for monocyte adhesion in animals and cells under diabetic conditions.
Monocyte adhesion assay, enzyme-linked immunosorbent assay, and Western blotting were used in analyzing samples from PAI-1-knockout (PAI-1-KO) mice or cultured human umbilical vein endothelial cells (HUVEC).
Diabetes in PAI-1-KO and wild-type mice was induced by intraperitoneal injection of streptozotocin (STZ). HUVEC was transfected with short interference RNA (siRNA) against PAI-1, tumor necrosis factor-α (TNFα), or toll-like receptor (TLR4), and then was treated with glycated low-density lipoproteins (glyLDL).
The adhesion of monocytes to aortic intima was reduced in PAI-1-KO mice, which was associated with decreased levels of TNFα and monocyte chemotactic protein-1 (MCP-1) in plasma and cardiovascular tissue, and increased abundances of urokinase plasminogen activator (uPA) and uPA receptor (uPAR) in cardiovascular tissue compared to wild-type mice. Significant reductions in monocyte adhesion, inflammatory, and fibrinolytic regulators were detected in cardiovascular tissue or plasma in diabetic PAI-1-KO mice compared to wild-type diabetic mice. Transfection of PAI-1, TNFα or TLR4 siRNA to HUVEC inhibited glyLDL-induced monocyte adhesion to EC. PAI-1 siRNA inhibited the abundances of TLR4 and TNFα in EC.
The findings suggest that PAI-1 is required for diabetes-induced monocyte adhesion via interactions with uPA/uPAR, and it also regulates TLR4 and TNFα expression in vascular EC. Inhibition of PAI-1 potentially reduces vascular inflammation under diabetic condition.
确定在糖尿病条件下，纤溶酶原激活物抑制剂-1 敲除（PAI-1）对动物和细胞中单核细胞黏附的需求。
使用单核细胞黏附测定法、酶联免疫吸附测定法和 Western 印迹法分析来自 PAI-1 敲除（PAI-1-KO）小鼠或培养的人脐静脉内皮细胞（HUVEC）的样本。
通过腹腔内注射链脲佐菌素（STZ）诱导 PAI-1-KO 和野生型小鼠的糖尿病。用针对 PAI-1、肿瘤坏死因子-α（TNFα）或 Toll 样受体 4（TLR4）的短发夹 RNA（siRNA）转染 HUVEC，然后用糖化低密度脂蛋白（glyLDL）处理。
与野生型小鼠相比，PAI-1-KO 小鼠主动脉内膜的单核细胞黏附减少，这与血浆和心血管组织中 TNFα 和单核细胞趋化蛋白-1（MCP-1）水平降低以及心血管组织中尿激酶型纤溶酶原激活物（uPA）和 uPA 受体（uPAR）丰度增加有关。与野生型糖尿病小鼠相比，糖尿病 PAI-1-KO 小鼠的心血管组织或血浆中单核细胞黏附、炎症和纤维溶解调节因子的减少更为显著。转染 PAI-1、TNFα 或 TLR4 siRNA 至 HUVEC 可抑制 glyLDL 诱导的单核细胞与 EC 的黏附。PAI-1 siRNA 抑制 EC 中 TLR4 和 TNFα 的丰度。
这些发现表明，PAI-1 通过与 uPA/uPAR 的相互作用，促进糖尿病诱导的单核细胞黏附，并且还调节血管内皮细胞中 TLR4 和 TNFα 的表达。在糖尿病条件下，抑制 PAI-1 可能会减少血管炎症。
