Institute for Clinical & Experimental Surgery, Saarland University, 66421, Homburg/Saar, Germany.
Sci Rep. 2019 Apr 16;9(1):6119. doi: 10.1038/s41598-019-42465-7.
Ischemia/reperfusion (I/R)-induced inflammation is associated with enhanced leukocyte rolling, adhesion and transmigration within the microcirculation. These steps are mediated by hypoxia-triggered signaling pathways, which upregulate adhesion molecule expression on endothelial cells and pericytes. We analyzed whether these cellular events are affected by maslinic acid (MA). Mitochondrial activity and viability of MA-exposed endothelial cells and pericytes were assessed by water-soluble tetrazolium (WST)-1 and lactate dehydrogenase (LDH) assays as well as Annexin V/propidium iodide (PI) stainings. Effects of MA on hypoxia and reoxygenation-induced expression of E-selectin, intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 were determined by flow cytometry. The subcellular localization of the NFκB subunit p65 was analyzed by immunofluorescence and Western blot. I/R-induced leukocytic inflammation was studied in MA- and vehicle-treated mouse dorsal skinfold chambers by intravital fluorescence microscopy and immunohistochemistry. MA did not affect viability, but suppressed the mitochondrial activity of endothelial cells. Furthermore, MA reduced adhesion molecule expression on endothelial cells and pericytes due to an inhibitory action on NFκB signaling. Numbers of adherent and transmigrated leukocytes were lower in post-ischemic tissue of MA-treated mice when compared to vehicle-treated controls. In addition, MA affected reactive oxygen species (ROS) formation, resulting in a diminished oxidative DNA damage. Hence, MA represents an attractive compound for the establishment of novel therapeutic approaches against I/R-induced inflammation.
缺血/再灌注（I/R）引起的炎症与微循环中白细胞滚动、黏附和迁移增强有关。这些步骤是由缺氧触发的信号通路介导的，这些信号通路上调内皮细胞和周细胞上黏附分子的表达。我们分析了这些细胞事件是否受熊果酸（MA）的影响。通过水溶性四唑盐（WST-1）和乳酸脱氢酶（LDH）测定以及 Annexin V/碘化丙啶（PI）染色评估 MA 暴露的内皮细胞和周细胞的线粒体活性和活力。通过流式细胞术确定 MA 对缺氧和再氧合诱导的 E-选择素、细胞间黏附分子（ICAM）-1 和血管细胞黏附分子（VCAM）-1 表达的影响。通过免疫荧光和 Western blot 分析 NFκB 亚基 p65 的亚细胞定位。通过活体荧光显微镜和免疫组织化学研究 MA 和载体处理的小鼠背部皮褶室中的 I/R 诱导的白细胞炎症。MA 不影响活力，但抑制内皮细胞的线粒体活性。此外，由于对 NFκB 信号的抑制作用，MA 降低了内皮细胞和周细胞上黏附分子的表达。与载体处理的对照组相比，在 MA 处理的小鼠缺血后组织中，黏附和迁移的白细胞数量减少。此外，MA 影响活性氧（ROS）的形成，导致氧化 DNA 损伤减少。因此，MA 代表了一种有吸引力的化合物，可用于建立针对 I/R 诱导的炎症的新的治疗方法。
