Rodriguez Monica P, Tsihlis Nick D, Emond Zachary M, Wang Zheng, Varu Vinit N, Jiang Qun, Vercammen Janet M, Kibbe Melina R
Division of Vascular Surgery, Department of Surgery, and Simpson Querrey Institute for BioNanotechnology, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
Division of Vascular Surgery, Department of Surgery, and Simpson Querrey Institute for BioNanotechnology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Division of Vascular Surgery, Department of Surgery, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois.
J Surg Res. 2015 Jun 1;196(1):180-9. doi: 10.1016/j.jss.2015.02.012. Epub 2015 Feb 13.
Nitric oxide (NO) more effectively inhibits neointimal hyperplasia in type 2 diabetic versus nondiabetic and type 1 diabetic rodents. NO also decreases the ubiquitin-conjugating enzyme UbcH10, which is critical to cell-cycle regulation. This study seeks to determine whether UbcH10 levels in the vasculature of diabetic animal models account for the differential efficacy of NO at inhibiting neointimal hyperplasia.
Vascular smooth muscle cells (VSMCs) harvested from nondiabetic lean Zucker (LZ) and type 2 diabetic Zucker diabetic fatty (ZDF) rats were exposed to high glucose (25 mM) and high insulin (24 nM) conditions to mimic the diabetic environment in vitro. LZ, streptozotocin-injected LZ (STZ, type 1 diabetic), and ZDF rats underwent carotid artery balloon injury (±10 mg PROLI/NO), and vessels were harvested at 3 and 14 d. UbcH10 was assessed by Western blotting and immunofluorescent staining.
NO more effectively reduced UbcH10 levels in LZ versus ZDF VSMCs; however, addition of insulin and glucose dramatically potentiated the inhibitory effect of NO on UbcH10 in ZDF VSMCs. Three days after balloon injury, Western blotting showed NO decreased free UbcH10 and increased polyubiquitinated UbcH10 levels by 35% in both STZ and ZDF animals. Fourteen days after injury, immunofluorescent staining showed increased UbcH10 levels throughout the arterial wall in all animal models. NO decreased UbcH10 levels in LZ and STZ rats but not in ZDF.
These data suggest a disconnect between UbcH10 levels and neointimal hyperplasia formation in type 2 diabetic models and contribute valuable insight regarding differential efficacy of NO in these models.
与非糖尿病和1型糖尿病啮齿动物相比，一氧化氮（NO）能更有效地抑制2型糖尿病啮齿动物的内膜增生。NO还能降低泛素结合酶UbcH10，而该酶对细胞周期调控至关重要。本研究旨在确定糖尿病动物模型血管中UbcH10水平是否能解释NO抑制内膜增生的不同效果。
从非糖尿病的瘦型Zucker（LZ）大鼠和2型糖尿病的Zucker糖尿病肥胖（ZDF）大鼠中分离出血管平滑肌细胞（VSMC），在体外将其置于高糖（25 mM）和高胰岛素（24 nM）条件下以模拟糖尿病环境。对LZ大鼠、注射链脲佐菌素的LZ大鼠（STZ，1型糖尿病）和ZDF大鼠进行颈动脉球囊损伤（±10 mg PROLI/NO），并在第3天和第14天采集血管。通过蛋白质免疫印迹法和免疫荧光染色评估UbcH10。
与ZDF VSMC相比，NO能更有效地降低LZ VSMC中的UbcH10水平；然而，添加胰岛素和葡萄糖可显著增强NO对ZDF VSMC中UbcH10的抑制作用。球囊损伤后3天，蛋白质免疫印迹法显示，在STZ和ZDF动物中，NO均可降低游离UbcH10水平，并使多聚泛素化UbcH10水平升高35%。损伤后14天，免疫荧光染色显示，在所有动物模型的动脉壁中，UbcH10水平均升高。NO可降低LZ和STZ大鼠中的UbcH10水平，但对ZDF大鼠无效。
这些数据表明，在2型糖尿病模型中，UbcH10水平与内膜增生形成之间存在脱节，并为NO在这些模型中的不同效果提供了有价值的见解。
