Dekigai H, Nakamura H, Bai J, Tanito M, Masutani H, Hirota K, Matsui H, Murakami M, Yodoi J
Department of Geriatric Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan.
Free Radic Res. 2001 Jul;35(1):23-30. doi: 10.1080/10715760100300561.
Thioredoxin (TRX) is a redox-active protein which is induced by oxidative stresses and shows a variety of biological activities including cytoprotection against oxidative stress. We recently reported that geranylgeranylacetone (GGA), an anti-ulcer drug, induces TRX in rat hepatocytes. In this study, we demonstrate that GGA promotes induction and secretion of TRX in rat gastric mucosal cells and human peripheral blood lymphocytes (PBLs). Western blotting and a sensitive sandwich ELISA showed that TRX was induced by GGA in the cell lysates and culture supernatants of rat gastric mucosal RGM-1 cells and human PBLs. LDH releasing assay showed that GGA protected rat gastric mucosal RGM-1 cells from ethanol-induced cytotoxicity. Moreover, exogenous recombinant wild type TRX decreased 51Cr release from primary cultured rat gastric mucosal cells incubated with ethanol or hydrogen peroxide in a dose-dependent manner, whereas recombinant mutant TRX (C32S/C35S), in which the two cysteines were replaced with serines in its active site, did not. These results indicate that GGA promotes the induction and secretion of TRX in a variety of types of cells and suggest that induced or secreted TRX may play an important role in the cytoprotective action of GGA on gastric mucosal cells.
硫氧还蛋白（TRX）是一种具有氧化还原活性的蛋白质，它可由氧化应激诱导产生，并具有多种生物学活性，包括对氧化应激的细胞保护作用。我们最近报道，抗溃疡药物香叶基香叶基丙酮（GGA）可在大鼠肝细胞中诱导TRX的产生。在本研究中，我们证明GGA可促进大鼠胃黏膜细胞和人外周血淋巴细胞（PBLs）中TRX的诱导和分泌。蛋白质免疫印迹法和灵敏的夹心酶联免疫吸附测定法表明，GGA可在大鼠胃黏膜RGM-1细胞和人PBLs的细胞裂解物及培养上清液中诱导TRX的产生。乳酸脱氢酶释放试验表明，GGA可保护大鼠胃黏膜RGM-1细胞免受乙醇诱导的细胞毒性作用。此外，外源性重组野生型TRX可使原代培养的大鼠胃黏膜细胞在与乙醇或过氧化氢孵育后，以剂量依赖的方式降低51Cr的释放，而在其活性位点两个半胱氨酸被丝氨酸取代的重组突变型TRX（C32S/C35S）则无此作用。这些结果表明，GGA可促进多种类型细胞中TRX的诱导和分泌，并提示诱导或分泌的TRX可能在GGA对胃黏膜细胞的细胞保护作用中发挥重要作用。
