Lung sensors in pulmonary diseases

Sensory information in the lung is mainly generated by airway sensors carried by the vagus nerves, yielding multiple reflex responses essential for breathing control and lung defense. When these sensors are activated in lung disease, they produce clinical signs, including cough, bronchoconstriction and mucus secretion, and alter disease course by reflexes and neuroimmune interaction.

Role of CGRP in Neuroimmune Interaction via NF-κB Signaling Genes in Glial Cells of Trigeminal Ganglia

Activation of the trigeminal system causes the release of various neuropeptides, cytokines, and other immune mediators. Calcitonin gene-related peptide (CGRP), which is a potent algogenic mediator, is expressed in the peripheral sensory neurons of trigeminal ganglion (TG). It affects the inflammatory responses and pain sensitivity by modulating the activity of glial cells. The primary aim of this study was to use array analysis to investigate the effect of CGRP on the glial cells of TG in regulating nuclear factor kappa B (NF-κB) signaling genes and to further check if CGRP in the TG can affect neuron-glia activation in the spinal trigeminal nucleus caudalis. The glial cells of TG were stimulated with CGRP or Minocycline (Min) + CGRP. The effect on various genes involved in NF-κB signaling pathway was analyzed compared to no treatment control condition using a PCR array analysis. CGRP, Min + CGRP or saline was directly injected inside the TG and the effect on gene expression of Egr1, Myd88 and Akt1 and protein expression of cleaved Caspase3 (cleav Casp3) in the TG, and c-Fos and glial fibrillary acidic protein (GFAP) in the spinal section containing trigeminal nucleus caudalis was analyzed. Results showed that CGRP stimulation resulted in the modulation of several genes involved in the interleukin 1 signaling pathway and some genes of the tumor necrosis factor pathway. Minocycline pre-treatment resulted in the modulation of several genes in the glial cells, including anti-inflammatory genes, and neuronal activation markers. A mild increase in cleav Casp3 expression in TG and c-Fos and GFAP in the spinal trigeminal nucleus of CGRP injected animals was observed. These data provide evidence that glial cells can participate in neuroimmune interaction due to CGRP in the TG via NF-κB signaling pathway.

Analgesic Mechanism of Sinomenine against Chronic Pain

Purified from the roots of the plant Sinomenium acutum, sinomenine is traditionally used in China and Japan for treating rheumatism and arthritis. Previously, we have demonstrated that sinomenine possessed a broad analgesic spectrum in various chronic pain animal models and repeated administration of sinomenine did not generate tolerance. In this review article, we discussed sinomenine’s analgesic mechanism with focus on its role on immune regulation and neuroimmune interaction. Sinomenine has distinct immunoregulative properties, in which glutamate, adenosine triphosphate, nitric oxide, and proinflammatory cytokines are thought to be involved. Sinomenine may alter the unbalanced neuroimmune interaction and inhibit neuroinflammation, oxidative stress, and central sensitization in chronic pain states. In conclusion, sinomenine has promising potential for chronic pain management in different clinical settings.

Neuroimmune mechanisms of pain: Basic science and potential therapeutic modulators

This narrative review aims to describe the role of peripheral and central immune responses to tissue and nerve damage in animal models, and to discuss the use of immunomodulatory agents in clinical practice and their perioperative implications. Animal models of pain have demonstrated that nerve injury activates immune signalling pathways that drive aberrant sensory processes, resulting in neuropathic and chronic pain. This response involves the innate immune system. T lymphocytes are also recruited. Glial cells surrounding the damaged nerves release cytokines and proinflammatory mediators that activate resident immune cells and recruit circulatory immune cells. Toll-like receptors on the glial cells play a crucial role in the pathogenesis of chronic pain. Animal models indicate an immune mechanism of neuropathic pain. Analgesic drugs and anaesthetic agents have varied effects on the neuroimmune interface. Evidence of a neuroimmune interaction is mainly from animal studies. Human studies are required to evaluate the clinical implications of this neuroimmune interaction.

Catecholamines as mediators of the neuroimmune interaction in multiple sclerosis

Исследование нейроиммунных взаимодействий является одним из наиболее развивающихся направлений в изучении патогенеза рассеянного склероза. Механизмы этого взаимодействия до конца не ясны. Полагают, что ключевое значение в регуляции этого взаимодействия может принадлежать нейротрансмиттерам. Наибольшее внимание привлекают катехоламины, в частности, дофамин и норадреналин, рецепторы к которым экспрессируют клетки как нервной, так иммунной систем. Установлено, что модулируя функции иммунокомпетентных клеток дофамин и норадреналин способны влиять на течение как экспериментального аутоиммунного энцефаломиелита, так и рассеянного склероза. В работе представлен обзор литературы и собственных данных о значении дофамина и норадреналина в регуляции взаимодействия нервной и иммунной систем при рассеянном склерозе. Обсуждаются возможные механизмы, опосредующие влияние дофамина и норадреналина на патогенез рассеянного склероза, в частности, влияние дофамина и норадреналина на функционирование Th17-клеток, а также на опосредованный дендритными клетками Th17-зависимый иммунный ответ, играющий одну из ключевых патогенетических ролей при рассеянном склерозе. The neuroimmune interaction is one of fast developing directions in studying the pathogenesis of multiple sclerosis. The mechanism of this interaction is not sufficiently understood. The key role in regulation of this interaction is assumed to belong to neurotransmitters, among which catecholamines, specifically dopamine and norepinephrine, attract the greatest attention. Cells of both nervous and immune systems express dopaminergic and noradrenergic receptors. Dopamine and norepinephrine can influence the course of experimental autoimmune encephalomyelitis and multiple sclerosis by modulating functions of immune cells. This review presents literature and authors’ own data on the role of dopamine and norepinephrine in regulation of the nervous and immune system interaction in multiple sclerosis and focuses on possible mechanisms mediating the effect of dopamine and norepinephrine on the pathogenesis of multiple sclerosis, particularly the effect of dopamine and norepinephrine on the Th17 cell function and the dendritic cell-mediated Th17 immune response that plays a key role in the pathogenesis of multiple sclerosis.

Novel role of NPY in neuroimmune interaction and lung growth after intrauterine growth restriction

Individuals with intrauterine growth restriction (IUGR) are at risk for chronic lung disease. Using a rat model, we showed in our previous studies that altered lung structure is related to IL-6/STAT3 signaling. As neuropeptide Y (NPY), a coneurotransmitter of the sympathetic nervous system, regulates proliferation and immune response, we hypothesized that dysregulated NPY after IUGR is linked to IL-6, impaired myofibroblast function, and alveolar growth. IUGR was induced in rats by isocaloric low-protein diet; lungs were analyzed on embryonic day (E) 21, postnatal day (P) 3, P12, and P23. Finally, primary neonatal lung myofibroblasts (pnF) and murine embryonic fibroblasts (MEF) were used to assess proliferation, apoptosis, migration, and IL-6 expression. At E21, NPY and IL-6 expression was decreased, and AKT/PKC and STAT3/AMPKα signaling was reduced. Early reduction of NPY/IL-6 was associated with increased chord length in lungs after IUGR at P3, indicating reduced alveolar formation. At P23, however, IUGR rats exhibited a catch-up of body weight and alveolar growth coupled with more proliferating myofibroblasts. These structural findings after IUGR were linked to activated NPY/PKC, IL-6/AMPKα signaling. Complementary, IUGR-pnF showed increased survival, impaired migration, and reduced IL-6 compared with control-pnF (Co-pnF). In contrast, NPY induced proliferation, migration, and increased IL-6 synthesis in fibroblasts. Additionally, NPY−/− mice showed reduced IL-6 signaling and less proliferation of lung fibroblasts. Our study presents a novel role of NPY during alveolarization: NPY regulates 1) IL-6 and lung STAT3/AMPKα signaling, and 2) proliferation and migration of myofibroblasts. These new insights in pulmonary neuroimmune interaction offer potential strategies to enable lung growth.