Initial Development of AEG-1 inactivation as a possible strategy for pain treatment

总结 适当的疼痛管理是一个未满足的医疗需求。阿片类药物仍然是一类重要的疼痛 药物，但它们在慢性，非恶性疼痛中的使用导致了现在所谓的 “阿片类药物流行病”显然，迫切需要确定和验证新的目标， 新型非阿片类镇痛药，有效和安全。这项提案的重点是一种新的分子， 星形胶质细胞升高基因-1（AEG-1），作为疼痛的可能靶点。AEG-1，也称为后粘附素（MTDH）， 是通过蛋白质-蛋白质相互作用介导其功能的支架蛋白。AEG-1作为支架发挥作用 在NF-kB信号传导途径中的多个中间信号复合物中的蛋白质，从而作为 NF-κ B活化的基本分子。NF-κ B是调节促炎性细胞因子的关键转录因子 细胞因子和AEG-1是炎症的主要调节剂。AEG-1 KO小鼠表现出对 炎症和AEG-1 KO巨噬细胞显示出对脂多糖（LPS）诱导的 NF-κ B活性和炎症基因表达。NF-kB在慢性炎症中起着重要的调节作用。 炎性疼痛。由于AEG-1调节NF-kB，因此可以假设AEG-1可能作为一个关键因素发挥作用， 调节疼痛机制的分子。我们的初步研究表明，伤害性行为和 炎症反应在两种完全弗氏佐剂（CFA）慢性炎性疼痛中均显著 与AEG-1 WT小鼠相比，AEG-1 KO小鼠中减少，而不影响运动活动和协调 动物们。这些发现确定了AEG-1在调节慢性疼痛中的关键作用和潜在靶点 缓解慢性疼痛我们假设AEG-1是调节疼痛行为的有效靶点， AEG-1抑制可能是开发新的慢性疼痛镇痛药的潜在策略。 我们将通过分析两种慢性神经病理性疼痛模型的疼痛行为来检验我们在目标1中的假设， AEG-1 KO和WT小鼠。目的2探讨巨噬细胞/小胶质细胞AEG-1细胞在体外培养中的作用。 骨髓细胞特异性条件性AEG-1 KO小鼠。在目标3中，我们将评估巨噬细胞靶向的 递送AEG-1 siRNA的纳米颗粒改善慢性炎性疼痛。我们的研究将确定AEG- 1作为一种新的和关键的调节分子调节疼痛反应，并将铺平道路， 疼痛的RNAi策略。多项临床试验正在进行中，以测试siRNA靶向各种基因， 从而建立这种策略在临床中管理疼痛的潜在应用。

Summary Adequate management of pain is an unmet medical need. Opioids remain an important class of pain medications but their use in chronic, non-malignant pain has contributed to what is now referred to as the “opioid epidemic”. There is clearly an urgent need to identify and validate novel targets allowing development of novel non-opioid analgesics that are effective and safe. This proposal focuses on a new molecule, Astrocyte elevated gene-1 (AEG-1), as a possible target for pain. AEG-1, also known as metadherin (MTDH), is a scaffold protein which mediates its function by protein-protein interaction. AEG-1 functions as a scaffold protein in multiple intermediary signaling complexes in NF-kB signaling pathway, thereby functioning as a fundamental molecule in NF-kB activation. NF-kB is a key transcription factor regulating pro-inflammatory cytokines and AEG-1 is a major regulator of inflammation. AEG-1 KO mice show a profound inhibition of inflammation and AEG-1 KO macrophages show profound inhibition of lipopolysaccharide (LPS)-induced NF-kB activity and inflammatory gene expression. NF-kB plays a major regulatory role in chronic inflammatory pain. Since AEG-1 regulates NF-kB it may be hypothesized that AEG-1 might function as a key molecule regulating pain mechanisms. Our preliminary studies demonstrate that nociceptive behaviors and inflammation in both the complete Freund adjuvant (CFA) chronic inflammatory pain were significantly reduced in AEG-1 KO mice compared to AEG-1 WT mice, without affecting motor activity and coordination of the animals. These findings identify a key role of AEG-1 in regulating chronic pain and a potential target for ameliorating chronic pain. We hypothesize that AEG-1 is a valid target regulating pain behaviors and AEG-1 inhibition might be developed as a potential strategy for developing new analgesics for chronic pain. We will test our hypothesis in Aim 1 by analyzing pain behaviors in two chronic neuropathic pain models in AEG-1 KO and WT mice. Aim 2 will investigate the role of macrophage/microglia AEG-1 cells by using myeloid cell-specific conditional AEG-1 KO mouse. In Aim 3 we will evaluate efficacy of macrophage-targeted nanoparticles delivering AEG-1 siRNA to ameliorate chronic inflammatory pain. Our studies will identify AEG- 1 as a novel and crucial regulatory molecule modulating pain response and will pave the way for developing RNAi strategy for pain. Multiple clinical trials are ongoing to test siRNAs targeting diverse genes in a variety of diseases thereby establishing potential application of this strategy to manage pain in the clinics.