Combinational Regulation of Inflammation in Otitis Media

描述（由申请人提供）：中耳炎（OM）是最常见的儿童细菌感染，也是儿童传导性听力损失的主要原因。炎症是OM的标志。开发高效疫苗仍然是一个巨大的挑战。不适当的抗生素治疗大大增加了抗生素耐药性。目前，由于对炎症的致病机制和有效的治疗靶点缺乏了解，没有有效的治疗方法，包括抗炎药。虽然适当的炎症对于根除病原体是必不可少的，但过度的炎症显然对宿主有害。因此，必须严格控制炎症。然而，炎症是如何被严格调控的仍然是未知的。我们的长期目标是了解炎症在OM中受到严格调控的分子机制，并确定有效的治疗靶点。在之前的资助期间，我们鉴定了一种新的去泛素化酶CYLD作为严格控制NTHi细菌诱导的OM炎症的关键负调节因子。鉴于过去在开发抗炎剂方面的努力，大多数策略集中于直接靶向阳性途径，例如，我？B激酶（IKK），以抑制炎症。虽然这些药物通常显示出合理的功效，但它们确实表现出显著的副作用，例如，增加了对感染和细胞凋亡的易感性，这阻碍了它们的进一步临床应用。因此，我们假设通过药理学抑制其自身的负调节因子来上调CYLD（炎症的关键负调节因子）可能代表用于治疗OM中的过度活动性炎症的新型且有利的抗炎策略，而不会引起靶向炎症正调节因子常见的严重不良反应（假设和创新）。事实上，我们的初步研究表明，CYLD本身进一步受到PDE 4的负控制; PDE 4的药理学抑制可能通过JNK上调CYLD表达而抑制炎症。因此，这些初步数据为我们研究PDE 4 B-JNK 2通路负调节CYLD的分子机制以及评估通过抑制其自身负调节剂上调CYLD在NTHi诱导的OM炎症中的治疗效果（短期目标）奠定了坚实的基础。我们的具体目标是：目标1。确定PDE 4 B是否是通过在体外和体内抑制CYLD介导NTHi诱导的炎症的关键。目标二。确定PDE 4 B如何在体外和体内通过选择性激活JNK 2抑制CYLD来调节NTHi诱导的炎症。目标3.在小鼠OM模型中确定TOE 4 B抑制对NTHi诱导的炎症的治疗效果。总体而言，拟议的研究将促进我们对OM分子发病机制的理解，并导致确定OM的新治疗靶点和新的抗炎剂。 公共卫生相关性：中耳炎（OM）是最常见的儿童细菌感染，每年就诊2450万人次，花费超过50亿美元，也是儿童传导性听力损失的主要原因。开发高效的OM疫苗仍然是一个巨大的挑战，不适当的抗生素治疗大大增加了抗生素耐药性，目前没有有效的治疗药物，包括抗炎药，由于对炎症的致病机制和有效的治疗靶点的了解不足。目前提出的研究将促进我们对OM分子发病机制的理解，并导致识别新的治疗靶点和开发新的抗炎治疗策略来抑制OM中的炎症。

DESCRIPTION (provided by applicant): Otitis media (OM) is the most common childhood bacterial infection and also the leading cause of conductive hearing loss in children. Inflammation is a hallmark of OM. Developing highly effective vaccines still remains a great challenge. Inappropriate antibiotic treatment increased antibiotic resistance substantially. Currently, there are no effective therapeutics including anti-inflammatory agents available for OM due to poor understanding of the pathogenic mechanism underlying inflammation and the effective therapeutic targets. Although appropriate inflammation is essential for eradicating pathogens, excessive inflammation is clearly detrimental to the host. Thus, inflammation must be tightly regulated. However, how inflammation is tightly regulated remains unknown. Our long-term objective is to understand the molecular mechanisms by which inflammation is tightly regulated in OM and to identify effective therapeutic targets. During previous grant period, we identified a novel deubiquitinase CYLD as the key negative regulator for tightly controlling NTHi bacteria-induced inflammation in OM. In view of the past effort in developing anti-inflammatory agents, most strategies have focused on directly targeting the positive pathways, e.g., the I?B kinase (IKK), to suppress inflammation. While these agents often showed reasonable efficacy, they did exhibit significant adverse effects, e.g., increased susceptibility to infection and apoptosis, which prevented their further clinical use. Thus, we hypothesized that up-regulating CYLD, the key negative regulator of inflammation, by pharmacological inhibition of its own negative regulator, may represent a novel and advantageous anti-inflammatory strategy for treating overactive inflammation in OM without causing serious adverse effects often seen with targeting positive regulator of inflammation (hypothesis & innovation). Indeed, our preliminary studies demonstrate that CYLD itself is further negatively controlled by PDE4; Pharmacological inhibition of PDE4 led to the suppression of inflammation by up-regulating CYLD expression likely via JNK. These preliminary data have thus laid a solid foundation for us to investigate the molecular mechanisms underlying negative regulation of CYLD by PDE4B-JNK2 pathway and evaluate the therapeutic effect of up-regulating CYLD by inhibiting its own negative regulator in NTHi-induced inflammation in OM (short-term objective). Our specific aims are: Aim 1. Determine if PDE4B is critical for mediating NTHi-induced inflammation by inhibiting CYLD in vitro & in vivo. Aim 2. Determine how PDE4B regulates NTHi-induced inflammation by inhibiting CYLD via selective activation of JNK2 in vitro & in vivo. Aim 3. Determine the therapeutic effect of PDE4B inhibition on NTHi-induced inflammation in a mouse OM model. Overall, the proposed studies will advance our understanding of molecular pathogenesis of OM and lead to identifying novel therapeutic targets and new anti-inflammatory agents for OM. PUBLIC HEALTH RELEVANCE: - Relevance to Public Health Otitis media (OM), inflammation of middle ear, is the most common childhood bacterial infection, accounting for 24.5 million visits and costing over $5 billion annually, and is also the leading cause of conductive hearing loss in children. Developing highly effective OM vaccines still remains a great challenge, inappropriate antibiotic treatment increased antibiotic resistance substantially and currently there are no effective therapeutics including anti-inflammatory agents available for OM due to poor understanding of the pathogenic mechanism underlying inflammation and the effective therapeutic targets. The currently proposed studies will advance our understanding of molecular pathogenesis of OM and lead to the identification of novel therapeutic targets and development of new anti-inflammatory therapeutic strategy for inhibiting inflammation in OM.