脾脏交感神经活性:非致病性驱动的慢性免疫介导炎症性疾病(IMIDs)的原因?
Sympathetic Nerve Hyperactivity in the Spleen: Causal for Nonpathogenic-Driven Chronic Immune-Mediated Inflammatory Diseases (IMIDs)?
机构信息
Department of Pathology and Human Anatomy, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA.
College of Arts and Sciences, Kent State University, Kent, OH 44304, USA.
出版信息
Int J Mol Sci. 2018 Apr 13;19(4):1188. doi: 10.3390/ijms19041188.
Immune-Mediated Inflammatory Diseases (IMIDs) is a descriptive term coined for an eclectic group of diseases or conditions that share common inflammatory pathways, and for which there is no definitive etiology. IMIDs affect the elderly most severely, with many older individuals having two or more IMIDs. These diseases include, but are not limited to, type-1 diabetes, obesity, hypertension, chronic pulmonary disease, coronary heart disease, inflammatory bowel disease, and autoimmunity, such as rheumatoid arthritis (RA), Sjőgren's syndrome, systemic lupus erythematosus, psoriasis, psoriatic arthritis, and multiple sclerosis. These diseases are ostensibly unrelated mechanistically, but increase in frequency with age and share chronic systemic inflammation, implicating major roles for the spleen. Chronic systemic and regional inflammation underlies the disease manifestations of IMIDs. Regional inflammation and immune dysfunction promotes targeted end organ tissue damage, whereas systemic inflammation increases morbidity and mortality by affecting multiple organ systems. Chronic inflammation and skewed dysregulated cell-mediated immune responses drive many of these age-related medical disorders. IMIDs are commonly autoimmune-mediated or suspected to be autoimmune diseases. Another shared feature is dysregulation of the autonomic nervous system and hypothalamic pituitary adrenal (HPA) axis. Here, we focus on dysautonomia. In many IMIDs, dysautonomia manifests as an imbalance in activity/reactivity of the sympathetic and parasympathetic divisions of the autonomic nervous system (ANS). These major autonomic pathways are essential for allostasis of the immune system, and regulating inflammatory processes and innate and adaptive immunity. Pathology in ANS is a hallmark and causal feature of all IMIDs. Chronic systemic inflammation comorbid with stress pathway dysregulation implicate neural-immune cross-talk in the etiology and pathophysiology of IMIDs. Using a rodent model of inflammatory arthritis as an IMID model, we report disease-specific maladaptive changes in β₂-adrenergic receptor (AR) signaling from protein kinase A (PKA) to mitogen activated protein kinase (MAPK) pathways in the spleen. Beta₂-AR signal "shutdown" in the spleen and switching from PKA to G-coupled protein receptor kinase (GRK) pathways in lymph node cells drives inflammation and disease advancement. Based on these findings and the existing literature in other IMIDs, we present and discuss relevant literature that support the hypothesis that unresolvable immune stimulation from chronic inflammation leads to a maladaptive disease-inducing and perpetuating sympathetic response in an attempt to maintain allostasis. Since the role of sympathetic dysfunction in IMIDs is best studied in RA and rodent models of RA, this IMID is the primary one used to evaluate data relevant to our hypothesis. Here, we review the relevant literature and discuss sympathetic dysfunction as a significant contributor to the pathophysiology of IMIDs, and then discuss a novel target for treatment. Based on our findings in inflammatory arthritis and our understanding of common inflammatory process that are used by the immune system across all IMIDs, novel strategies to restore SNS homeostasis are expected to provide safe, cost-effective approaches to treat IMIDs, lower comorbidities, and increase longevity.
免疫介导的炎症性疾病(IMIDs)是一个描述性术语,用于描述一组具有共同炎症途径的疾病或病症,这些疾病或病症没有明确的病因。IMIDs 对老年人的影响最为严重,许多老年人患有两种或两种以上的 IMIDs。这些疾病包括但不限于 1 型糖尿病、肥胖症、高血压、慢性肺部疾病、冠心病、炎症性肠病和自身免疫性疾病,如类风湿关节炎(RA)、干燥综合征、系统性红斑狼疮、银屑病、银屑病关节炎和多发性硬化症。这些疾病在机制上表面上没有关联,但随着年龄的增长而增加频率,并具有慢性全身炎症,暗示脾脏起着重要作用。慢性全身和局部炎症是 IMIDs 疾病表现的基础。局部炎症和免疫功能障碍导致靶向终末器官组织损伤,而全身炎症通过影响多个器官系统增加发病率和死亡率。慢性炎症和失调的细胞介导免疫反应导致许多与年龄相关的医学疾病。IMIDs 通常是自身免疫介导的,或被怀疑是自身免疫性疾病。另一个共同特征是自主神经系统和下丘脑-垂体-肾上腺(HPA)轴的失调。在这里,我们专注于自主神经功能障碍。在许多 IMIDs 中,自主神经功能障碍表现为自主神经系统(ANS)的交感和副交感分支的活动/反应性失衡。这些主要的自主途径对于免疫系统的全身适应、调节炎症过程以及先天和适应性免疫至关重要。自主神经病理学是所有 IMIDs 的特征和因果特征。慢性全身炎症伴应激通路失调提示神经-免疫相互作用在 IMIDs 的病因和发病机制中起作用。我们使用炎症性关节炎的啮齿动物模型作为 IMID 模型,报告了脾脏中蛋白激酶 A(PKA)到丝裂原激活蛋白激酶(MAPK)途径的β₂-肾上腺素能受体(AR)信号从蛋白激酶 A(PKA)到丝裂原激活蛋白激酶(MAPK)途径的疾病特异性适应性变化。脾脏中β₂-AR 信号的“关闭”以及淋巴结细胞中从 PKA 到 G 蛋白偶联受体激酶(GRK)途径的转换驱动炎症和疾病进展。基于这些发现和其他 IMIDs 中的现有文献,我们提出并讨论了相关文献,这些文献支持这样一种假设,即慢性炎症引起的不可解决的免疫刺激导致适应性疾病诱导和持续的交感反应,试图维持全身适应。由于交感神经功能障碍在 IMIDs 中的作用在 RA 和 RA 的啮齿动物模型中研究得最好,因此这种 IMID 是用于评估与我们假设相关的数据的主要模型。在这里,我们回顾了相关文献,并讨论了交感神经功能障碍作为 IMIDs 病理生理学的重要贡献者,然后讨论了一种新的治疗靶点。基于我们在炎症性关节炎中的发现以及我们对免疫系统在所有 IMIDs 中使用的常见炎症过程的理解,恢复 SNS 平衡的新策略有望为治疗 IMIDs、降低合并症和提高寿命提供安全、经济有效的方法。