Wu Jianghong, Wang Yuren, Liang Shuguang, Ma Haiching
Reaction Biology Corp, Malvern, PA, USA.
Drug Des Devel Ther. 2014 May 24;8:583-600. doi: 10.2147/DDDT.S60283. eCollection 2014.
Caspases are currently known as the central executioners of the apoptotic pathways. Inhibition of apoptosis and promotion of normal cell survival by caspase inhibitors would be a tremendous benefit for reducing the side effects of cancer therapy and for control of neurodegenerative disorders such as Parkinson's, Alzheimer's, and Huntington's diseases. The objective of this study was to discover small-molecule caspase inhibitors with which to achieve cytoprotective effect. We completed the high-throughput screening of Bionet's 37,500-compound library (Key Organics Limited, Camelford, Cornwall, UK) against caspase-1, -3, and -9 and successfully identified 43 initial hit compounds. The 43 hit compounds were further tested for cytoprotective activity against staurosporine-induced cell death in NIH3T3 cells. Nineteen compounds were found to have significant cytoprotective effects in cell viability assays. One of the compounds, RBC1023, was demonstrated to protect NIH3T3 cells from staurosporine-induced caspase-3 cleavage and activation. RBC1023 was also shown to protect against staurosporine-induced impairment of mitochondrial membrane potential. DNA microarray analysis demonstrated that staurosporine treatment induced broad global gene expression alterations, and RBC1023 co-treatment significantly restored these changes, especially of the genes that are related to cell growth and survival signaling such as Egr1, Cdc25c, cdkn3, Rhob, Nek2, and Taok1. Collectively, RBC1023 protects NIH3T3 cells against staurosporine-induced apoptosis via inhibiting caspase activity, restoring mitochondrial membrane potential, and possibly upregulating some cell survival-related gene expressions and pathways.
半胱天冬酶目前被认为是细胞凋亡途径的核心执行者。半胱天冬酶抑制剂抑制细胞凋亡并促进正常细胞存活，这对于减少癌症治疗的副作用以及控制神经退行性疾病（如帕金森病、阿尔茨海默病和亨廷顿病）将带来巨大益处。本研究的目的是发现具有细胞保护作用的小分子半胱天冬酶抑制剂。我们完成了针对生物网络公司的37500种化合物文库（英国康沃尔郡卡梅尔福德的Key Organics Limited公司）对半胱天冬酶-1、-3和-9的高通量筛选，并成功鉴定出43种初始活性化合物。对这43种活性化合物进一步测试其对NIH3T3细胞中星形孢菌素诱导的细胞死亡的细胞保护活性。在细胞活力测定中发现有19种化合物具有显著的细胞保护作用。其中一种化合物RBC1023被证明可保护NIH3T3细胞免受星形孢菌素诱导的半胱天冬酶-3切割和激活。RBC1023还显示可防止星形孢菌素诱导的线粒体膜电位损伤。DNA微阵列分析表明，星形孢菌素处理诱导了广泛的全基因组表达改变，而RBC1023联合处理显著恢复了这些变化，尤其是与细胞生长和存活信号相关的基因，如Egr1、Cdc25c、cdkn3、Rhob、Nek2和Taok1。总体而言，RBC1023通过抑制半胱天冬酶活性、恢复线粒体膜电位以及可能上调一些细胞存活相关基因的表达和信号通路来保护NIH3T3细胞免受星形孢菌素诱导的细胞凋亡。
