Orexinergic Modulation of Experimental Sepsis

项目摘要 复杂的生物体通过炎症保护自己免受威胁，炎症在一定程度上是由大脑控制的。 涉及神经递质增食欲素的通路。在脓毒症中，炎症变得调节失调，器官 就会出现功能障碍。我们已经证明在实验性脓毒症(盲肠)中食欲素能活动减弱。 结扎和穿刺法(CLP)。该项目的主要目标是确定脓毒症是如何导致 食欲素能活动减弱影响器官功能，改变宿主炎症反应和 导致死亡率，并确定纠正食欲素能活动减少是否逆转这些变化。 我们将通过三个具体目标来解决这些目标。 具体目标1.确定CLP引起的食欲素能活动丧失对器官功能和 病理学和生存论。检查自主神经系统对这些变化的影响。 方法：我们将通过侧脑室注射食欲素逆转CLP引起的食欲素能活动的丧失并检查 这如何改变心脏、肺、肝、肾和免疫功能，以及生存。我们将使用外围设备 β-肾上腺素能和M受体阻滞剂，以确定自主神经系统的贡献。此外， 我们将确定在几个不同的时间点进行脑室注射食欲素是否能提高14天的存活率。 特定目的2.确定CLP引起的食欲素能活动丧失对脑胆碱能的影响 活跃性和炎症反射。 方法：我们将逆转CLP引起的食欲素能活动的丧失，方法是脑室注射增食欲素和 确定这如何影响基底前脑、毒鼠碱和炎症反射活动。为了实现这一目标，我们 将检查脑室注射增食欲素对1)胆碱-乙酰转移酶(ChAT)共定位和 C-fos免疫染色，表明胆碱能活性，2)血清肿瘤坏死因子α水平， 3)采集、刺激的脾细胞培养上清液中肿瘤坏死因子α、IL-6和HMGB1的水平。。 特定目的3.确定CLP引起的脑胆碱能活动丧失对食欲素能的影响 活动，因此，在HR，RR，T和脑下垂体激素分泌的变化。 方法：我们将使用克诺马林逆转CLP引起的脑胆碱能活性丧失，Xonomine是一种中枢M1 激动剂，或icv尼古丁，并确定食欲素能活动和HR、RR、T和垂体激素分泌 被修复了。然后我们将检查食欲素拮抗剂almore xant的效果。 证明CLP诱导的食欲素能系统的改变调节器官功能障碍、炎症 反应和存活率可能会重新引导研究和治疗范式，将重点放在大脑作为 脓毒症的主要驱动力，克服了进展的关键障碍。证明我们可以改变这些 增强大脑胆碱能活性的作用可能提供一种新的、临床上可行的治疗途径 在这种致命的，高度流行的混乱中。

Project Summary Complex organisms protect themselves against threats via inflammation, which is in part controlled by brain pathways involving the neurotransmitter orexin. In sepsis, inflammation becomes dysregulated and organ dysfunction develops. We have shown that orexinergic activity is attenuated in experimental sepsis (cecal ligation and puncture (CLP) in mice). The main objectives of this project are to identify how sepsis-induced attenuation of orexinergic activity effects organ function, alters the host inflammatory response and contributes to mortality, and to determine if correcting decreased orexinergic activity reverses these changes. We will address these objectives via three Specific Aims. Specific Aim 1. Determine the effects of CLP-induced loss of orexinergic activity on organ function and pathology and on survival. Examine the contribution of the autonomic nervous system to these changes. Approach: We will reverse the CLP-induced loss of orexinergic activity with ICV orexin injection and examine how this alters cardiac, pulmonary, hepatic, renal and immune function, and survival. We will use peripheral β-adrenergic and muscarinic blockade to identify the contribution of the autonomic nervous system. Further, we will determine if an ICV orexin infusion delivered at several different time points improves 14-day survival. Specific Aim 2. Determine the effects of the CLP-induced loss of orexinergic activity on brain cholinergic activity and on the inflammatory reflex. Approach: We will reverse the CLP-induced loss of orexinergic activity with an ICV injection of orexin and determine how this effects basal forebrain muscarinic and inflammatory reflex activity. To accomplish this we will examine the effects of an ICV orexin injection on 1) co-localization of choline-acetyltransferase (ChAT) and c-fos immunostaining, indicative of cholinergic activity, in appropriate brain sections, 2) serum levels of TNFα, IL-6 and HMGB1 and 3) TNFα, IL-6 and HMGB1 levels in the medium of harvested, stimulated splenocytes. . Specific Aim 3. Determine the effects of CLP-induced loss of brain cholinergic activity on orexinergic activity and, as a result, on alterations in HR, RR, T and pituitary hormone secretion. Approach: We will reverse the CLP-induced loss of brain cholinergic activity with xanomeline, a central M1 agonist, or ICV nicotine, and determine if orexinergic activity and HR, RR, T and pituitary hormone secretion are restored. We will then examine the effects of the orexin antagonist almorexant Demonstrating that CLP-induced changes in the orexinergic system modulate organ dysfunction, inflammatory responses and survival could re-direct the investigative and therapeutic paradigm to focus on the brain as a primary driver of sepsis, overcoming a critical barrier to progress. Demonstrating that we can alter these effects by enhancing brain cholinergic activity could provide a new, clinically viable therapeutic avenue for use in this deadly, highly prevalent disorder.