Center for Genomics and Proteomics, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea.
Electrophoresis. 2012 Dec;33(24):3756-63. doi: 10.1002/elps.201200345. Epub 2012 Dec 4.
Microglial cells act as the first and main form of active immune defense in the central nervous system related to inflammation and neurodegenerative disease. Lipopolysaccharide (LPS) induces many genes encoding inflammatory mediators, including cytokines such as tumor necrosis factor-α, interleukin-1β, (IL-1β), and IL-6, chemokines, and prostaglandins in microglial cells. Quantitative proteomics methods with isobaric chemical labeling using tandem mass tags and 2D-nano LC-ESI-MS/MS were used to systematically analyze proteomic changes in microglia responding to LPS stimulation. As a result, we found that the expression level of 21 proteins in human microglial cells changed after activation. Among those, one of the strong mitogen-activated protein kinase (MAPK) regulator proteins, CMPK1 was highly upregulated after LPS stimulation in human microglial cells. We detected and validated upregulation of MAPK including ERK1/2, p38, and SAPK/JNK by immunohistochemistry and Western blotting. NFκB, strong transcription factor of CMPK1, was translocated to the nucleus from the cytosol by high contents screening after LPS stimulation. Taken together, we conclude that MAPK signaling plays an important role in LPS-induced human microglial activation related to inflammatory response.
小胶质细胞作为与炎症和神经退行性疾病相关的中枢神经系统中主动免疫防御的第一和主要形式。脂多糖（LPS）诱导许多编码炎症介质的基因表达，包括细胞因子如肿瘤坏死因子-α、白细胞介素-1β（IL-1β）和 IL-6、趋化因子和前列腺素在小胶质细胞中。使用串联质量标签和 2D-nano LC-ESI-MS/MS 的等压化学标记定量蛋白质组学方法用于系统分析 LPS 刺激下小胶质细胞的蛋白质组变化。结果，我们发现人小胶质细胞在激活后 21 种蛋白质的表达水平发生变化。其中，一种强烈的丝裂原活化蛋白激酶（MAPK）调节蛋白 CMPK1 在人小胶质细胞中受到 LPS 刺激后高度上调。我们通过免疫组织化学和 Western blot 检测并验证了 MAPK 的上调，包括 ERK1/2、p38 和 SAPK/JNK。NFκB，CMPK1 的强转录因子，通过 LPS 刺激后的高内涵筛选从细胞质易位到细胞核。综上所述，我们得出结论，MAPK 信号通路在 LPS 诱导的与炎症反应相关的人小胶质细胞激活中起重要作用。
