Paradoxical Effects of NF-kB in Ischemia; Novel Polymeric Gene Silencing in vivo

描述(由申请人提供)：尽管基因在心脏病中的作用得到了认可，但目前对转录因子NF-kB在心脏保护和缺血/再灌注(I/R)损伤的相反过程中的作用机制知之甚少。这一关键的知识差距阻碍了在心血管疾病中使用核因子-kB抑制或细胞因子阻断的治疗方法的成功开发。该提案的目的是填补这一知识空白；全面了解NF-kB及其依赖的基因表达网络影响I/R损伤、心脏保护、I/R后功能障碍和心力衰竭的机制。我们提出的中心假设是，核因子-kB通过调节不同组依赖于核因子-kB的基因来调节对不同刺激的不同反应。我们提出了三个具体的目标：1)阐明了核因子-kB对I/R和PO后细胞死亡的拮抗作用所依赖的一组基因；2)确定了核因子-kB调节基因表达以引起I/R后细胞死亡和PO后细胞存活的转录机制；3)确定了PGAA复合体在体内急、慢性缺血后疾病中的生物学效应和治疗潜力。该方法是采用假设驱动的微阵列策略，利用我们的IkBDN小鼠(阻断NF-kB)来描绘与NF-kB依赖的前损伤和心脏保护作用相关的功能相关的NF-kB依赖的基因。我们还将使用一种创新的非病毒聚合核酸传递技术(PGAA)来阻断体内的NF-kB激活(诱骗)和沉默NF-kB依赖的基因(SiRNA)。我们希望这些结果将提供一个机制上的理解，即依赖于核因子-kB的基因是如何在心脏中形成差异反应的。公共卫生相关性：这项拟议的研究具有重要意义，因为它将导致确定新的治疗目标和开发新的缺血性心脏病治疗方法。该提案开发了一套新颖而创新的基础科学试剂，可用于体内DNA和siRNA的传递。该提案具有很高的翻译性，因为它开发了PGAA介导的诱骗和siRNA传递在临床前研究中的治疗用途。

DESCRIPTION (provided by applicant): Though the role of genes in heart disease is appreciated, there is currently little understanding of the mechanism by which the transcription factor NF-kB contributes to the antithetical processes of cardioprotection and ischemia/reperfusion (I/R) injury. This Critical Gap In Knowledge prevents the successful development of therapies employing NF-kB inhibition or cytokine blockade in cardiovascular disease. The objective of the proposal is to fill this knowledge gap; to develop a comprehensive understanding of the mechanism by which NF-kB and NF-kB-dependent gene expression networks affect I/R injury, cardioprotection, post-I/R dysfunction and heart failure. We offer the central hypothesis that NF-kB mediates differential responses to different stimuli by regulating distinct sets of NF-kB-dependent genes. We propose three specific aims; 1) Delineate the sets of NF-kB-dependent genes that underlie the antithetical effects of NF-kB upon cell death after I/R and PO, 2) Determine the transcriptional mechanism by which NF-kB modulates gene expression to evoke cell death after I/R and cell survival after PO, 3) Determine the biological effects and therapeutic potential of PGAA polyplexes during acute and chronic post-ischemic disease in vivo. The approach is to employ an hypothesis-driven microarray strategy that takes advantage of our IkBDN mice (block NF-kB) to delineate NF-kB-dependent genes functionally associated with NF-kB-dependent pro-injury and cardioprotective effects. We will also employ an innovative non-viral polymeric nucleic acid delivery technology (PGAA) to block NF-kB activation (decoys) and to silence NF-kB-dependent genes (siRNA) in vivo. We expect that the results will provide a mechanistic understanding of how NF-kB-dependent genes underlie differential responses in the heart. Public Health Relevance: The proposed research is significant because it will lead to identification of new therapeutic targets and development of novel therapies for ischemic heart disease. The proposal develops a novel and innovative set of reagents for basic science that can be used for DNA and siRNA delivery in vivo. The proposal is highly translational in that it develops the therapeutic use of PGAA-mediated decoy and siRNA delivery in pre- clinical studies.