Division of Biochemistry, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Hokkaido, Japan.
Division of Clinical Cariology and Endodontology, Department of Oral Rehabilitation, School of Dentistry, Health Sciences University of Hokkaido, Hokkaido, Japan.
Biomed Res Int. 2018 Feb 20;2018:2370438. doi: 10.1155/2018/2370438. eCollection 2018.
To analyze the effect of three mitogen-activated protein kinase (MAPK) inhibitors, namely, SB202190 (p38 inhibitor), SP600125 (JNK inhibitor), and PD98059 (ERK inhibitor) in Dex-stimulated MDPC-23 cell differentiation and mineralization.
Experiment was divided into five groups, control (cells without Dex and inhibitors treatment), Dex (cells with Dex treatment but without inhibitors), Dex + SB202190, Dex + SP600125, and Dex + PD98059. Cell differentiation was assessed by alkaline phosphatase (ALP) activity assay and real time RT-PCR. Cell mineralization was investigated by alizarin red staining.
Exposure to SB202190 (20 M) significantly decreased the mineral deposition in Dex-treated cells as demonstrated by alizarin red staining. Treatment of SP600125 (20 M) attenuated the mineralization as well, albeit at a lower degree as compared to SB202190 (20 M). Similarly, SB202190 (20 M) completely abrogated the ALP activity stimulated by Dex at six days in culture, while no changes were observed with regard to ALP activity in SP600125 (20 M) and PD98059 (20 M) treated cells. The upregulation of bone sialoprotein (BSP), ALP, and osteopontin (OPN) in Dex challenged cells was completely inhibited by SB202190.
Blockade of p38-MAPK signaling pathway resulted in significant inhibition of ALP activity, mineralization, and downregulation of osteogenic markers. The data implicated that p38 signaling pathway plays a critical role in the regulation of MDPC-23 cells differentiation and mineralization.
分析三种丝裂原活化蛋白激酶（MAPK）抑制剂，即 SB202190（p38 抑制剂）、SP600125（JNK 抑制剂）和 PD98059（ERK 抑制剂）在 Dex 刺激的 MDPC-23 细胞分化和矿化中的作用。
实验分为五组，对照组（无 Dex 和抑制剂处理的细胞）、Dex 组（有 Dex 处理但无抑制剂组）、Dex+SB202190 组、Dex+SP600125 组和 Dex+PD98059 组。通过碱性磷酸酶（ALP）活性测定和实时 RT-PCR 评估细胞分化。通过茜素红染色研究细胞矿化。
暴露于 20μM 的 SB202190 显著减少了 Dex 处理细胞的矿化沉积，如茜素红染色所示。20μM 的 SP600125 处理也减弱了矿化，尽管程度低于 20μM 的 SB202190。同样，SB202190（20μM）完全阻断了 Dex 刺激的六天培养物中的 ALP 活性，而 SP600125（20μM）和 PD98059（20μM）处理的细胞中未观察到 ALP 活性的变化。骨涎蛋白（BSP）、ALP 和骨桥蛋白（OPN）在 Dex 刺激的细胞中的上调完全被 SB202190 抑制。
阻断 p38-MAPK 信号通路导致 ALP 活性、矿化和成骨标志物的下调显著抑制。数据表明，p38 信号通路在调节 MDPC-23 细胞分化和矿化中起关键作用。
