Center for Human Genetics, Brown Foundation Institute of Molecular Medicine, the University of Texas Health Science Center, Houston, Texas, USA.
Mol Ther Nucleic Acids. 2013 Oct 1;2(10):e125. doi: 10.1038/mtna.2013.53.
Target substrate-specific hammerhead ribozyme cleaves the specific mRNA efficiently and results in the inhibition of gene expression. In humans, overproduction of apolipoprotein B (apoB) is positively associated with premature coronary artery diseases. The goal of this study is to demonstrate that long-term reduction of apoB gene expression using hammerhead ribozyme would result in inhibition of atherosclerosis development. We designed two hammerhead ribozymes targeted at the nucleotides of apoB mRNA GUC(2326) (designated RB1) and GUA(6679) (designated RB15), and we used self-complementary adeno-associated virus 8.2 (scAAV8.2) vector to deliver these active ribozymes of RB1, RB15, combination of RB1/RB15, and an inactive hammerhead ribozyme RB15 mutant to atherosclerosis-prone LDb mice (Ldlr(-/-)Apobec1(-/-)). LDb mice lack both low density lipoproteins (LDL) receptor (Ldlr(-/-)) and apoB mRNA editing enzyme (Apobec1(-/-)) genes and develop atherosclerosis spontaneously. After the RB1, RB15, or combination of RB1/RB15 ribozymes treatment, the LDb mice had significantly decreased plasma triglyceride and apoB levels, resulting in markedly decreased of atherosclerotic lesions, Furthermore, the active ribozymes treatment decreased the levels of diacylglycerol acyltransferase 1 (Dgat1) mRNA and the levels of multiple diacylglycerol (DAG) molecular species. These results provide the first evidence that decreased apoB levels results to reduction of Dgat1 expression and triglyceride levels (TAG), which had a significant impact on the development of atherosclerosis.Molecular Therapy-Nucleic Acids (2013) 2, e125; doi:10.1038/mtna.2013.53; published online 1 October 2013.
靶向特定底物的锤头状核酶能够有效地切割特定的 mRNA，从而抑制基因表达。在人类中，载脂蛋白 B (apoB) 的过度产生与早发冠心病呈正相关。本研究的目的是证明使用锤头状核酶长期降低 apoB 基因表达会抑制动脉粥样硬化的发展。我们设计了两种靶向 apoB mRNA GUC(2326) (命名为 RB1) 和 GUA(6679) (命名为 RB15) 的锤头状核酶，并使用自我互补的腺相关病毒 8.2 (scAAV8.2) 载体将这些活性 RB1、RB15、RB1/RB15 组合和无活性锤头状核酶 RB15 突变体递送到易患动脉粥样硬化的 LDb 小鼠 (Ldlr(-/-)Apobec1(-/-))。 LDb 小鼠缺乏低密度脂蛋白 (LDL) 受体 (Ldlr(-/-)) 和 apoB mRNA 编辑酶 (Apobec1(-/-)) 基因，会自发发展为动脉粥样硬化。在 RB1、RB15 或 RB1/RB15 核酶治疗后， LDb 小鼠的血浆甘油三酯和 apoB 水平显著降低，导致动脉粥样硬化病变明显减少。此外，活性核酶治疗降低了二酰基甘油酰基转移酶 1 (Dgat1) mRNA 的水平和多个二酰基甘油 (DAG) 分子种类的水平。这些结果首次提供了证据，证明降低 apoB 水平会导致 Dgat1 表达和甘油三酯水平 (TAG) 的降低，这对动脉粥样硬化的发展有显著影响。《分子治疗-核酸》（2013 年）2，e125；doi:10.1038/mtna.2013.53；在线出版于 2013 年 10 月 1 日。
