Nagahira A, Nagahira K, Murafuji H, Abe K, Magota K, Matsui M, Oikawa S
Suntory Biomedical Research Limited, 1-1-1 Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka, 618-8503, Japan.
Biochem Biophys Res Commun. 2001 Mar 9;281(4):1030-6. doi: 10.1006/bbrc.2001.4476.
An isoquinoline derivative, 5-methyl-7,8-dimethoxy-1-phenylpyrazolo[5,4-c]isoquinoline (compound 1), was identified as a novel inhibitor of LPS-induced TNF-alpha production by cell-based screening. Compound 1 suppressed LPS-induced TNF-alpha production in RAW264.7 cells and murine peritoneal macrophages in a dose-dependent manner similar to SB203580, known as a specific inhibitor of p38 MAPK. It also inhibited an LPS-induced increase in serum TNF-alpha in a mouse endotoxic shock model with an ED(50) of approximately 10 mg/kg. Compound 1 had little effect on the incorporation of [3H]-leucine into the cells, while it suppressed LPS-induced TNF-alpha mRNA levels in RAW264.7 cells. The results indicate that suppression of TNF-alpha production was not a result of nonspecific inhibition of de novo translation but was based on the decreased TNF-alpha mRNA levels. The in vitro kinase assay revealed that compound 1 did not strongly inhibit p38 MAPK activity, its potency being much lower than that of SB203580, suggesting that the TNF-alpha-suppressive action of compound 1 cannot be attributed to the inhibition of p38 MAPK. Furthermore, in contrast to SB203580, it significantly inhibited the growth of RAW264.7 and THP-1 cells in a cytostatic manner. Compound 1 is likely to have antiinflammatory and antiproliferative effects by acting on some molecule other than p38 MAPK that contributes to both LPS-induced TNF-alpha production and the cell growth of monocyte/macrophages.
一种异喹啉衍生物，5-甲基-7,8-二甲氧基-1-苯基吡唑并[5,4-c]异喹啉（化合物1），通过基于细胞的筛选被鉴定为脂多糖（LPS）诱导的肿瘤坏死因子-α（TNF-α）产生的新型抑制剂。化合物1以剂量依赖性方式抑制RAW264.7细胞和小鼠腹腔巨噬细胞中LPS诱导的TNF-α产生，其作用方式类似于已知的p38丝裂原活化蛋白激酶（MAPK）特异性抑制剂SB203580。在小鼠内毒素休克模型中，它还能抑制LPS诱导的血清TNF-α升高，半数有效剂量（ED50）约为10 mg/kg。化合物1对[3H]-亮氨酸掺入细胞的过程影响很小，但能抑制RAW264.7细胞中LPS诱导的TNF-α mRNA水平。结果表明，TNF-α产生的抑制不是由于对从头翻译的非特异性抑制，而是基于TNF-α mRNA水平的降低。体外激酶分析表明，化合物1对p38 MAPK活性没有强烈抑制作用，其效力远低于SB203580，这表明化合物1的TNF-α抑制作用不能归因于对p38 MAPK的抑制。此外，与SB203580不同，它能以细胞生长抑制的方式显著抑制RAW264.7和THP-1细胞的生长。化合物1可能通过作用于除p38 MAPK之外的某些分子发挥抗炎和抗增殖作用，这些分子既参与LPS诱导的TNF-α产生，也参与单核细胞/巨噬细胞的细胞生长。
