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

描述（由申请人提供）：虽然基因在心脏病中的作用已得到认可，但目前对转录因子NF-kB参与心脏保护和缺血/再灌注（I/R）损伤的对立过程的机制知之甚少。这一关键的知识缺口阻碍了利用NF-kB抑制或细胞因子阻断治疗心血管疾病的成功发展。该提案的目的是填补这一知识空白；全面了解NF-kB和NF-kB依赖性基因表达网络影响I/R损伤、心脏保护、I/R后功能障碍和心力衰竭的机制。我们提出了一个中心假设，即NF-kB通过调节不同的NF-kB依赖基因来调节对不同刺激的不同反应。我们提出三个具体目标；1)阐明NF-kB对I/R和PO后细胞死亡的拮抗作用的NF-kB依赖性基因；2)确定NF-kB调控基因表达诱导I/R后细胞死亡和PO后细胞存活的转录机制；3)确定体内急性和慢性缺血性疾病期间PGAA复合物的生物学效应和治疗潜力。该方法采用假设驱动的微阵列策略，利用我们的IkBDN小鼠（阻断NF-kB）来描述NF-kB依赖基因在功能上与NF-kB依赖的促损伤和心脏保护作用相关。我们还将采用一种创新的非病毒聚合核酸递送技术（PGAA）来阻断NF-kB激活（诱饵），并在体内沉默NF-kB依赖基因（siRNA）。我们期望这些结果将为nf - kb依赖性基因在心脏差异反应中的机制理解提供依据。公共卫生相关性：拟议的研究具有重要意义，因为它将导致缺血性心脏病的新治疗靶点的确定和新疗法的发展。该提案为基础科学开发了一套新颖和创新的试剂，可用于DNA和siRNA的体内递送。该建议是高度翻译的，因为它在临床前研究中开发了pgaa介导的诱饵和siRNA递送的治疗用途。

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.