scholarly journals The Role of Immune Cells in Post-Stroke Angiogenesis and Neuronal Remodeling: The Known and the Unknown

2021 ◽  
Vol 12 ◽  
Author(s):  
Yinzhong Ma ◽  
Shilun Yang ◽  
Qianyan He ◽  
Dianhui Zhang ◽  
Junlei Chang
Keyword(s):  
Immune Cells ◽  
Inflammatory Responses ◽  
Neuronal Cell ◽  
Neural Tissue ◽  
Experimental Stroke ◽  
Functional Rehabilitation ◽  
Post Stroke ◽  
Repair Processes ◽  
Neuronal Remodeling

Following a cerebral ischemic event, substantial alterations in both cellular and molecular activities occur due to ischemia-induced cerebral pathology. Mounting evidence indicates that the robust recruitment of immune cells plays a central role in the acute stage of stroke. Infiltrating peripheral immune cells and resident microglia mediate neuronal cell death and blood-brain barrier disruption by releasing inflammation-associated molecules. Nevertheless, profound immunological effects in the context of the subacute and chronic recovery phase of stroke have received little attention. Early attempts to curtail the infiltration of immune cells were effective in mitigating brain injury in experimental stroke studies but failed to exert beneficial effects in clinical trials. Neural tissue damage repair processes include angiogenesis, neurogenesis, and synaptic remodeling, etc. Post-stroke inflammatory cells can adopt divergent phenotypes that influence the aforementioned biological processes in both endothelial and neural stem cells by either alleviating acute inflammatory responses or secreting a variety of growth factors, which are substantially involved in the process of angiogenesis and neurogenesis. To better understand the multiple roles of immune cells in neural tissue repair processes post stroke, we review what is known and unknown regarding the role of immune cells in angiogenesis, neurogenesis, and neuronal remodeling. A comprehensive understanding of these inflammatory mechanisms may help identify potential targets for the development of novel immunoregulatory therapeutic strategies that ameliorate complications and improve functional rehabilitation after stroke.

scholarly journals Succinate Is an Inflammation-Induced Immunoregulatory Metabolite in Macrophages

Metabolites ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 372 ◽  
Author(s):  
Karl J. Harber ◽  
Kyra E. de Goede ◽  
Sanne G. S. Verberk ◽  
Elisa Meinster ◽  
Helga E. de Vries ◽  
...  
Keyword(s):  
Immune Responses ◽  
Immune Cells ◽  
Immune Cell ◽  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Cell Phenotype ◽  
Independent Manner ◽  
Inflammatory Macrophages ◽  
Necrosis Factor

Immunometabolism revealed the crucial role of cellular metabolism in controlling immune cell phenotype and functions. Macrophages, key immune cells that support progression of numerous inflammatory diseases, have been well described as undergoing vast metabolic rewiring upon activation. The immunometabolite succinate particularly gained a lot of attention and emerged as a crucial regulator of macrophage responses and inflammation. Succinate was originally described as a metabolite that supports inflammation via distinct routes. Recently, studies have indicated that succinate and its receptor SUCNR1 can suppress immune responses as well. These apparent contradictory effects might be due to specific experimental settings and particularly the use of distinct succinate forms. We therefore compared the phenotypic and functional effects of distinct succinate forms and receptor mouse models that were previously used for studying succinate immunomodulation. Here, we show that succinate can suppress secretion of inflammatory mediators IL-6, tumor necrosis factor (TNF) and nitric oxide (NO), as well as inhibit Il1b mRNA expression of inflammatory macrophages in a SUCNR1-independent manner. We also observed that macrophage SUCNR1 deficiency led to an enhanced inflammatory response without addition of exogenous succinate. While our study does not reveal new mechanistic insights into how succinate elicits different inflammatory responses, it does indicate that the inflammatory effects of succinate and its receptor SUCNR1 in macrophages are clearly context dependent.

scholarly journals Niacin protects against abdominal aortic aneurysm formation via GPR109A independent mechanisms: role of NAD+/nicotinamide

2019 ◽  
Vol 116 (14) ◽  
pp. 2226-2238 ◽  
Author(s):  
Tetsuo Horimatsu ◽  
Andra L Blomkalns ◽  
Mourad Ogbi ◽  
Mary Moses ◽  
David Kim ◽  
...  
Keyword(s):  
Immune Cells ◽  
Inflammatory Cell ◽  
Immune Cell ◽  
Inflammatory Responses ◽  
Aortic Aneurysms ◽  
Cell Infiltration ◽  
Protective Effects ◽  
Abdominal Aortic ◽  
G Protein Coupled

Abstract Aims Chronic adventitial and medial infiltration of immune cells play an important role in the pathogenesis of abdominal aortic aneurysms (AAAs). Nicotinic acid (niacin) was shown to inhibit atherosclerosis by activating the anti-inflammatory G protein-coupled receptor GPR109A [also known as hydroxycarboxylic acid receptor 2 (HCA2)] expressed on immune cells, blunting immune activation and adventitial inflammatory cell infiltration. Here, we investigated the role of niacin and GPR109A in regulating AAA formation. Methods and results Mice were supplemented with niacin or nicotinamide, and AAA was induced by angiotensin II (AngII) infusion or calcium chloride (CaCl2) application. Niacin markedly reduced AAA formation in both AngII and CaCl2 models, diminishing adventitial immune cell infiltration, concomitant inflammatory responses, and matrix degradation. Unexpectedly, GPR109A gene deletion did not abrogate the protective effects of niacin against AAA formation, suggesting GPR109A-independent mechanisms. Interestingly, nicotinamide, which does not activate GPR109A, also inhibited AAA formation and phenocopied the effects of niacin. Mechanistically, both niacin and nicotinamide supplementation increased nicotinamide adenine dinucleotide (NAD+) levels and NAD+-dependent Sirt1 activity, which were reduced in AAA tissues. Furthermore, pharmacological inhibition of Sirt1 abrogated the protective effect of nicotinamide against AAA formation. Conclusion Niacin protects against AAA formation independent of GPR109A, most likely by serving as an NAD+ precursor. Supplementation of NAD+ using nicotinamide-related biomolecules may represent an effective and well-tolerated approach to preventing or treating AAA.

scholarly journals HDL in Immune-Inflammatory Responses: Implications beyond Cardiovascular Diseases

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1061
Author(s):  
Fabrizia Bonacina ◽  
Angela Pirillo ◽  
Alberico L. Catapano ◽  
Giuseppe D. Norata
Keyword(s):  
Immune Cells ◽  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Membrane Lipid ◽  
High Density Lipoproteins ◽  
Protective Effects ◽  
The Road ◽  
Plasma Membrane Lipid ◽  
Inflammatory Burden

High density lipoproteins (HDL) are heterogeneous particles composed by a vast array of proteins and lipids, mostly recognized for their cardiovascular (CV) protective effects. However, evidences from basic to clinical research have contributed to depict a role of HDL in the modulation of immune-inflammatory response thus paving the road to investigate their involvement in other diseases beyond those related to the CV system. HDL-C levels and HDL composition are indeed altered in patients with autoimmune diseases and usually associated to disease severity. At molecular levels, HDL have been shown to modulate the anti-inflammatory potential of endothelial cells and, by controlling the amount of cellular cholesterol, to interfere with the signaling through plasma membrane lipid rafts in immune cells. These findings, coupled to observations acquired from subjects carrying mutations in genes related to HDL system, have helped to elucidate the contribution of HDL beyond cholesterol efflux thus posing HDL-based therapies as a compelling interventional approach to limit the inflammatory burden of immune-inflammatory diseases.

The attenuation of pain behaviour and serum interleukin-6 concentration by nimesulide in a rat model of neuropathic pain

2010 ◽  
Vol 1 (4) ◽  
pp. 229-234 ◽  
Author(s):  
Taraneh Moini Zanjani ◽  
Masoumeh Sabetkasaei ◽  
Behnaz Karimian ◽  
Farzaneh Labibi ◽  
Babak Farokhi ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neuropathic Pain ◽  
Immune System ◽  
Immune Cells ◽  
Interleukin 6 ◽  
Inflammatory Responses ◽  
Pain Behaviour ◽  
Behavioural Tests

AbstractBackgroundEvidence for a role of immune system in hyperalgesic pain states is increasing. Recent work in neuroimmunology suggests that the immune system does more than simply perform its well known functions of recognizing and removing invading pathogens and tumors. Interest in neuroinflammation and neuroimmune activation has grown rapidly in recent years with the recognition of the role of central nervous system inflammatiom and immune responses in the aetiology of pain states. Among various theories, the role of inflammatory responses of the injured nerve has recently received attention. Cytokines are heterogenous group of polypeptides that activate the immune system and mediate inflammatory responses, acting on a variety of tissue, including the peripheral and central nervous system. Interleukin-6 (IL-6) a pro-inflammatory cytokine, is potentially important in pain aetiology, have pronociceptive actions. Neuropathic pain may be due to a primary insult to the peripheral or central nervous system. Substances released during inflammation from immune cells play an important role in the development and maintenance of chronic pain. Nimesulide, a highly selective cox-2 inhibitor, effectively reduces hyperalgesia due to peripherally administration of inflammatory agents like formalin. The safety of nimesulide was reported for some conditions in which other NSAIDs are contraindicated. Here we have determined the effect of nimesulide on pain behaviour and serum IL-6 level in chronic constriction injury (CCI) model of neuropathic pain.MethodsExperiments were carried out on male Wistar rats, (weight 150–200 g, n = 8). Rats were divided into 3 different groups: 1-CCI + saline 0.9% 2Sham + saline 0.9% (control) 3CCI + drug. Nimesulide (1.25, 2.5, 5 mg/kg, i.p.) was injected 1h before surgery and continued daily to day 14 post-ligation. 42 °C water for thermal hyperalgesia, von Frey filaments for mechanical allodynia, acetone test for cool allodynia and 10 °C water for cold hyperalgesia were respectively used as pain behavioural tests. Behavioural tests were recorded before surgery and on postoperative days 1, 3, 5, 7, 10, 14 and the serum concentration of IL-6 was determined at the day 14.ResultsThe results of this study showed a decrease in hyperalgesia and allodynia following nimesulide administration.ConclusionsIt appears that nimesulide was able to reduce pain behaviour due to nerve inflammation and a parallel decrease in the serum IL-6 concentration was observed.ImplicationsThe immune system is an important mediator in the cascade of events that ultimately results in hyperalgesia. Cytokines contribute to the patheogenesis of neuropathic pain, therefore drugs that inhibit cytokine release from immune cells may reduce inflammatory pain states.

scholarly journals RhTrx-1 ameliorates miroglial neuroinflammation after cerebral ischemic stroke

2020 ◽  
Author(s):  
Yang Jiao ◽  
Jianjian Wang ◽  
Huixue Zhang ◽  
Yuze Cao ◽  
Yang Qu ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Inflammatory Response ◽  
Inflammatory Responses ◽  
Inflammatory Factors ◽  
Experimental Stroke ◽  
Inflammasome Activation ◽  
Cerebral Ischemic

Abstract Background Microglia are rapidly activated after ischemic stroke and participate in the occurrence of neuroinflammation, which exacerbates the injury of ischemic stroke. Receptor Interacting Serine Threonine Kinase 1 (RIPK1) is thought to be involved in the development of inflammatory responses, but its role in ischemic microglia remains unclear. Here, we applied recombinant human thioredoxin-1 (rhTrx-1), a potential neuroprotective agent, to explore the role of rhTrx-1 in inhibiting RIPK1-mediated neuroinflammatory responses in microglia. Method Middle cerebral artery occlusion (MCAO) and Oxygen and glucose deprivation (OGD) were conducted for in vivo and in vitro experimental stroke models. The expression of RIPK1 in microglia after ischemia was examined. The inflammatory response of microglia was analyzed after treatment with rhTrx-1 and Necrostatin-1 (Nec-1, inhibitors of RIPK1), and the mechanisms were explored. In addition, the effects of rhTrx-1 on neurobehavioral deficits and cerebral infarct volume were examined. Results RIPK1 expression was detected in microglia after ischemia. Molecular docking results showed that rhTrx-1 could directly bind to RIPK1. In vitro experiments found that rhTrx-1 reduced necroptosis, mitochondrial membrane potential damage, Reactive oxygen species (ROS) accumulation and NLR Family, pyrin domain-containing 3 protein (NLRP3) inflammasome activation by inhibiting RIPK-1 expression, and regulated microglial M1/M2 phenotypic changes, thereby reducing the release of inflammatory factors. Consistently, in vivo experiments found that rhTrx-1 treatment attenuated cerebral ischemic injury by inhibiting the inflammatory response. Conclusion Our study demonstrates the role of RIPK1 in microglia-arranged neuroinflammation after cerebral ischemia. Administration of rhTrx-1 provides neuroprotection in ischemic stroke-induced microglial neuroinflammation by inhibiting RIPK1 expression.

scholarly journals Sex Differences in Otolaryngology: Focus on the Emerging Role of Estrogens in Inflammatory and Pro-Resolving Responses

2021 ◽  
Vol 22 (16) ◽  
pp. 8768
Author(s):  
Sheng-Dean Luo ◽  
Tai-Jan Chiu ◽  
Wei-Chih Chen ◽  
Ching-Shuen Wang
Keyword(s):  
Sex Differences ◽  
Sex Hormones ◽  
Immune Cells ◽  
Vocal Fold ◽  
Hormone Receptors ◽  
Inflammatory Responses ◽  
Proinflammatory Responses ◽  
Males And Females ◽  
Nose And Throat

Otolaryngology (also known as ear, nose, and throat (ENT)) diseases can be significantly affected by the level of sex hormones, which indicates that sex differences affect the manifestation, pathophysiology, and outcomes of these diseases. Recently, increasing evidence has suggested that proinflammatory responses in ENT diseases are linked to the level of sex hormones. The sex hormone receptors are present on a wide variety of immune cells; therefore, it is evident that they play crucial roles in regulating the immune system and hence affect the disease progression of ENT diseases. In this review, we focus on how sex hormones, particularly estrogens, regulate ENT diseases, such as chronic rhinosinusitis, vocal fold polyps, thyroid cancer, Sjögren’s syndrome, and head and neck cancers, from the perspectives of inflammatory responses and specialized proresolving mediator-driven resolution. This paper aims to clarify why considering sex differences in the field of basic and medical research on otolaryngology is a key component to successful therapy for both males and females in the future.

scholarly journals Impacts of Immunometabolism on Male Reproduction

2021 ◽  
Vol 12 ◽  
Author(s):  
Lijun Ye ◽  
Wensi Huang ◽  
Su Liu ◽  
Songchen Cai ◽  
Ling Hong ◽  
...  
Keyword(s):  
Immune Cells ◽  
Inflammatory Responses ◽  
Male Reproduction ◽  
Metabolic Dysfunction ◽  
Potential Significance ◽  
Metabolic Intermediates ◽  
Hpt Axis ◽  
And Control

The physiological process of male reproduction relies on the orchestration of neuroendocrine, immune, and energy metabolism. Spermatogenesis is controlled by the hypothalamic-pituitary-testicular (HPT) axis, which modulates the production of gonadal steroid hormones in the testes. The immune cells and cytokines in testes provide a protective microenvironment for the development and maturation of germ cells. The metabolic cellular responses and processes in testes provide energy production and biosynthetic precursors to regulate germ cell development and control testicular immunity and inflammation. The metabolism of immune cells is crucial for both inflammatory and anti-inflammatory responses, which supposes to affect the spermatogenesis in testes. In this review, the role of immunometabolism in male reproduction will be highlighted. Obesity, metabolic dysfunction, such as type 2 diabetes mellitus, are well documented to impact male fertility; thus, their impacts on the immune cells distributed in testes will also be discussed. Finally, the potential significance of the medicine targeting the specific metabolic intermediates or immune metabolism checkpoints to improve male reproduction will also be reassessed.

scholarly journals The Role of Microglia during West Nile Virus Infection of the Central Nervous System

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 485 ◽  
Author(s):  
Sarah Stonedahl ◽  
Penny Clarke ◽  
Kenneth L. Tyler
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
West Nile Virus ◽  
Immune Cells ◽  
Neuronal Cell ◽  
The United States ◽  
Health Concern ◽  
West Nile ◽  
The Central Nervous System

Encephalitis resulting from viral infections is a major cause of hospitalization and death worldwide. West Nile Virus (WNV) is a substantial health concern as it is one of the leading causes of viral encephalitis in the United States today. WNV infiltrates the central nervous system (CNS), where it directly infects neurons and induces neuronal cell death, in part, via activation of caspase 3-mediated apoptosis. WNV infection also induces neuroinflammation characterized by activation of innate immune cells, including microglia and astrocytes, production of inflammatory cytokines, breakdown of the blood-brain barrier, and infiltration of peripheral leukocytes. Microglia are the resident immune cells of the brain and monitor the CNS for signs of injury or pathogens. Following infection with WNV, microglia exhibit a change in morphology consistent with activation and are associated with increased expression of proinflammatory cytokines. Recent research has focused on deciphering the role of microglia during WNV encephalitis. Microglia play a protective role during infections by limiting viral growth and reducing mortality in mice. However, it also appears that activated microglia are triggered by T cells to mediate synaptic elimination at late times during infection, which may contribute to long-term neurological deficits following a neuroinvasive WNV infection. This review will discuss the important role of microglia in the pathogenesis of a neuroinvasive WNV infection. Knowledge of the precise role of microglia during a WNV infection may lead to a greater ability to treat and manage WNV encephalitis.

Exercise protects from cancer through regulation of immune function and inflammation

2017 ◽  
Vol 45 (4) ◽  
pp. 905-911 ◽  
Author(s):  
Pernille Hojman
Keyword(s):  
Exercise Training ◽  
Immune Cells ◽  
Inflammatory Responses ◽  
Immune Surveillance ◽  
Hallmarks Of Cancer ◽  
Anticancer Treatment ◽  
Underlying Mechanisms ◽  
Cancer Settings ◽  
Target Cancer

Exercise training has been extensively studied in cancer settings as part of prevention or rehabilitation strategies, yet emerging evidence suggests that exercise training can also directly affect tumor-specific outcomes. The underlying mechanisms for this exercise-dependent cancer protection are just starting to be elucidated. To this end, evasion of immune surveillance and tumor-associated inflammation are established as hallmarks of cancer, and exercise may target cancer incidence and progression through regulation of these mechanisms. Here, I review the role of exercise in protection from cancer through mobilization and activation of cytotoxic immune cells, restriction of inflammatory signaling pathways in myeloid immune cells, and regulation of acute and chronic systemic inflammatory responses. In conclusion, I propose that exercise has the potential to target tumor growth through regulation of immune and inflammatory functions, and exercise may be pursued as anticancer treatment through incorporation into standard oncological therapy to the benefit of the cancer patients.

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