Alves-Lopes Rhéure, Neves Karla B, Montezano Augusto C, Harvey Adam, Carneiro Fernando S, Touyz Rhian M, Tostes Rita C
From the Ribeirao Preto Medical School (R.A.-L., K.B.N., F.S.C., R.C.T.) and Faculty of Pharmaceutical Sciences of Ribeirao Preto (K.B.N.), University of Sao Paulo, Brazil; and Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (A.C.M., A.H., R.M.T.).
Hypertension. 2016 Oct;68(4):1056-64. doi: 10.1161/HYPERTENSIONAHA.116.07518. Epub 2016 Aug 15.
Oxidative stress plays an important role in diabetes mellitus (DM)-associated vascular injury. DM is an important risk factor for erectile dysfunction. Functional and structural changes in internal pudendal arteries (IPA) can lead to erectile dysfunction. We hypothesized that downregulation of nuclear factor E2-related factor 2 (Nrf2), consequent to increased nicotinamide adenine dinucleotide phosphate oxidase 1 (NOX1)-derived reactive oxygen species (ROS), impairs IPA function in DM. IPA and vascular smooth muscle cells from C57BL/6 (control) and NOX1 knockout mice were used. DM was induced by streptozotocin in C57BL/6 mice. Functional properties of IPA were assessed using a myograph, protein expression and peroxiredoxin oxidation by Western blot, RNA expression by polymerase chain reaction, carbonylation by oxyblot assay, ROS generation by lucigenin, nitrotyrosine, and amplex red, and Rho kinase activity and nuclear accumulation of Nrf2 by ELISA. IPA from diabetic mice displayed increased contractions to phenylephrine (control 138.5±9.5 versus DM 191.8±15.5). ROS scavenger, Nrf2 activator, NOX1 and Rho kinase inhibitors normalized vascular function. High glucose increased ROS generation in IPA vascular smooth muscle cell. This effect was abrogated by Nrf2 activation and not observed in NOX1 knockout vascular smooth muscle cell. High glucose also increased levels of nitrotyrosine, protein oxidation/carbonylation, and Rho kinase activity, but reduced Nrf2 activity and expression of Nrf2-regulated genes (catalase [25.6±0.05%], heme oxygenase-1 [21±0.1%], and
NAD(P)H: quinone oxidoreductase 1 [22±0.1%]) and hydrogen peroxide levels. These effects were not observed in vascular smooth muscle cell from NOX1 knockout mice. In these cells, high glucose increased hydrogen peroxide levels. In conclusion, Rho kinase activation, via NOX1-derived ROS and downregulation of Nrf2 system, impairs IPA function in DM. These data suggest that Nrf2 is vasoprotective in DM-associated erectile dysfunction.
氧化应激在糖尿病（DM）相关的血管损伤中起重要作用。DM是勃起功能障碍的重要危险因素。阴部内动脉（IPA）的功能和结构变化可导致勃起功能障碍。我们假设，由于烟酰胺腺嘌呤二核苷酸磷酸氧化酶1（NOX1）产生的活性氧（ROS）增加，核因子E2相关因子2（Nrf2）下调会损害DM中IPA的功能。使用来自C57BL/6（对照）和NOX1基因敲除小鼠的IPA和血管平滑肌细胞。通过链脲佐菌素诱导C57BL/6小鼠患DM。使用肌张力测定仪评估IPA的功能特性，通过蛋白质印迹法检测蛋白质表达和过氧化物酶氧化，通过聚合酶链反应检测RNA表达，通过氧化印迹法检测羰基化，通过光泽精、硝基酪氨酸和氨基苯甲酰罗丹明检测ROS生成，通过酶联免疫吸附测定法检测Rho激酶活性和Nrf2的核积累。糖尿病小鼠的IPA对去氧肾上腺素的收缩反应增加（对照138.5±9.5对DM 191.8±15.5）。ROS清除剂、Nrf2激活剂、NOX1和Rho激酶抑制剂可使血管功能恢复正常。高糖增加了IPA血管平滑肌细胞中的ROS生成。Nrf2激活可消除这种作用，而在NOX1基因敲除的血管平滑肌细胞中未观察到这种作用。高糖还增加了硝基酪氨酸水平、蛋白质氧化/羰基化和Rho激酶活性，但降低了Nrf2活性以及Nrf2调节基因（过氧化氢酶[25.6±0.05%]、血红素加氧酶-1[21±0.1%]和NAD（P）H：醌氧化还原酶1[22±0.1%]）的表达以及过氧化氢水平。在NOX1基因敲除小鼠的血管平滑肌细胞中未观察到这些作用。在这些细胞中，高糖增加了过氧化氢水平。总之，通过NOX1产生的ROS和Nrf2系统下调，Rho激酶激活损害了DM中IPA的功能。这些数据表明Nrf2在DM相关的勃起功能障碍中具有血管保护作用。
Zotero 插件