莪术抑制晶状体上皮细胞增殖的信号转导机制

目的 探讨天然药物莪术（rhizoma curcumae，RC）对体外培养的晶状体上皮细胞（1ensepithelial cell，LEC）增殖的抑制作用，并从信号转导方面研究其抑制LEC增殖的作用机制，为寻求防治后发性白内障（after cataract）的确切有效药物提供实验依据。方法 用牛LEC进行原代和传代培养，取第三代细胞。用10ng／ml重组人碱性成纤维细胞生长因子（recombinant human basic fibroblast growth factor，rhbFGF）诱导LEC增殖。同时分别将5mg／ml、10mg／ml、20mg／ml的莪术作用于增殖状态下的LEC72小时。（1）通过四甲基偶氮唑蓝（methyl thiazolyl tetrazolium，MTT）比色测定法检测莪术对LEC增殖的抑制程度；（2）用钙荧光指示剂Fura-2／AM测定莪术抑制LEC增殖时细胞内游离钙离子浓度（Ca^2＋]i）变化;（3）用放射免疫分析法测定莪术抑制LEC增殖时细胞内环化腺苷酸（cyclic adenosine monophosphate，cAMP）和环化鸟苷酸（cyclicguanosine monophosphate，cGMP）浓度变化。结果 莪术可明显抑制LEC增殖。抑制LEC增殖时细胞内游离钙离子浓度（Ca^2＋]i）升高，细胞内cAMP浓度显著升高，细胞内cGMP浓度显著降低，cAMP／cGMP比值升高，并具有剂量依赖关系。结论 诱导Ca^2＋]i升高，激活细胞内Ca^2＋信号转导途径；上调细胞内cAMP水平，下调细胞内cGMP水平，使cAMP／cGMP比值升高，激活细胞内cAMP-PKA、cGMP-PKG信号转导途径可能是莪术抑制LEC增殖的作用机制之一。莪术能够明显抑制LEC增殖的作用，有望成为防治后发性白内障的有效药物。

Mechanism of signal transduction about proliferative inhibition of rhizoma curcumae on lens epithelial cell

OBJECTIVE To investigate the proliferative inhibition of lens epithelial cell(LEC)by rhizoma curcumae(RC)and to further study their mechanism of signal transduction,in order to provide scientific basis for pursuing safe and effective natural drugs to prevent and cure after cataract.METHODS Bovine LEC were cultured and were used for experiment at generation 3.LEC proliferation were induced by 10ng/ml recombinant human basic fibroblast growth factor(rhbFGF),in the same time,5mg/ml,10mg/ml,20mg/ml RC were added to the LEC separately.The following studies were made after 72 hour incubation.(1)The effects of proliferative inhibition by RC on the LEC were measured with methyl thiazolyl tetrazolium(MTT)assay method.(2)The changes of the intracellular free calcium concentration(Ca~ 2+ i)induced by RC were detected by fluometry probed with fluorescent indicator fura-2 acecoxymethl ester(fura-2/AM).(3)The changes of the intracellular cAMP and cGMP concentration induced by RC were observed by radioimmunoassay techniques.RESULTS (1)RC can significantly inhibit the proliferation of LEC induced by rhbFGF and these effects were dose dependent.(2)Ca~ 2+ i in LEC treated by RC was markedly increased and this increase was dose dependent.(3)The intracellular cAMP concentration was greatly increased and the intracellular cGMP concentration was greatly decreased,cAMP/cGMP was greatly increased treated by RC and the change was dose dependent.CONCLUSIONS (1)RC can markedly inhibit the LEC proliferation.(2)Ca~ 2+ signal pathway may play a significant role in inhibiting proliferation of LEC by RC.(3)There are close relationship between cAMP-PKA,cGMP-PKG signal pathway and the proliferative inhibition of LEC by RC.(4)The inhibitive effects of RC on the LEC proliferation make it probably become reliable and effective drugs to prevent and cure after cataract.