Department of Surgery, Mackay Memorial Hospital, Taipei, Taiwan.
J Surg Res. 2011 May 15;167(2):e299-305. doi: 10.1016/j.jss.2009.11.738. Epub 2009 Dec 22.
We previously have shown that platonin, a potent antioxidant, significantly attenuated inflammatory molecules up-regulation in RAW264.7 cells, a murine macrophage-like cell line. Inflammatory molecules expression is under the regulation of activator protein-1 (AP-1), a crucial transcription factor and a heterodimeric protein that composes of proteins from c-Jun and c-Fos families. AP-1 expression is regulated by mitogen-activated protein kinases (MAPKs). We sought to elucidate the effects of platonin on MAPKs and AP-1 up-regulation in activated RAW264.7 cells.
RAW264.7 cells were allocated to receive phosphate buffered saline, lipopolysaccharide (LPS, 100 ng/mL), platonin (100 μM), or platonin plus LPS and designated as the PBS, LPS, platonin, or LPS + platonin group, respectively. After harvesting, expression of the investigated molecules was evaluated.
The cytosolic protein concentrations of MAPKs, including extracellular regulated kinase (ERK), c-jun N-terminal kinase (JNK), and p38 MAPK, of the LPS group were significantly higher than those of the PBS and platonin groups. The nuclear protein concentrations of AP-1, including c-Jun and c-Fos, and the AP-1-DNA binding activity of the LPS group were also significantly higher than those of the PBS and platonin groups. In contrast, the concentrations of ERK, JNK, and p38 MAPK of the LPS + platonin group were significantly lower than those of the LPS group. Moreover, the concentrations of c-Jun and c-Fos and the AP-1-DNA binding activity of the LPS + platonin group were significantly lower than those of the LPS group.
Platonin significantly attenuated MAPKs and AP-1 upregulation in activated RAW264.7 cells.
我们之前已经表明，褪黑素是一种有效的抗氧化剂，可显著减轻 RAW264.7 细胞（一种鼠源巨噬细胞样细胞系）中炎症分子的上调。炎症分子的表达受激活蛋白-1（AP-1）的调控，AP-1 是一种关键的转录因子，由 c-Jun 和 c-Fos 家族的蛋白质组成。AP-1 的表达受丝裂原激活蛋白激酶（MAPKs）的调控。我们试图阐明褪黑素对激活的 RAW264.7 细胞中 MAPKs 和 AP-1 上调的影响。
将 RAW264.7 细胞分为磷酸盐缓冲液（PBS）、脂多糖（LPS，100ng/mL）、褪黑素（100μM）或褪黑素加 LPS 组，分别命名为 PBS、LPS、褪黑素和 LPS+褪黑素组。收获后，评估所研究分子的表达。
LPS 组的 MAPKs 细胞浆蛋白浓度，包括细胞外调节激酶（ERK）、c-Jun N 端激酶（JNK）和 p38 MAPK，明显高于 PBS 和褪黑素组。LPS 组的核蛋白浓度 AP-1，包括 c-Jun 和 c-Fos，以及 AP-1-DNA 结合活性也明显高于 PBS 和褪黑素组。相比之下，LPS+褪黑素组的 ERK、JNK 和 p38 MAPK 浓度明显低于 LPS 组。此外，LPS+褪黑素组的 c-Jun 和 c-Fos 浓度以及 AP-1-DNA 结合活性明显低于 LPS 组。
褪黑素可显著减轻激活的 RAW264.7 细胞中 MAPKs 和 AP-1 的上调。
