scholarly journals The Role of Macrophages in the Pathogenesis of ALI/ARDS

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaofang Huang ◽  
Huiqing Xiu ◽  
Shufang Zhang ◽  
Gensheng Zhang

Despite development in the understanding of the pathogenesis of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), the underlying mechanism still needs to be elucidated. Apart from leukocytes and endothelial cells, macrophages are also essential for the process of the inflammatory response in ALI/ARDS. Notably, macrophages play a dual role of proinflammation and anti-inflammation based on the microenvironment in different pathological stages. In the acute phase of ALI/ARDS, resident alveolar macrophages, typically expressing the alternatively activated phenotype (M2), shift into the classically activated phenotype (M1) and release various potent proinflammatory mediators. In the later phase, the M1 phenotype of activated resident and recruited macrophages shifts back to the M2 phenotype for eliminating apoptotic cells and participating in fibrosis. In this review, we summarize the main subsets of macrophages and the associated signaling pathways in three different pathological phases of ALI/ARDS. According to the current literature, regulating the function of macrophages and monocytes might be a promising therapeutic strategy against ALI/ARDS.

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 394.1-394
Author(s):  
A. Hukara ◽  
M. Rudnik ◽  
C. B. Rufer ◽  
O. Distler ◽  
P. Blyszczuk ◽  
...  

Background:Fos-like 2 (Fosl-2) is a transcription factor of the AP-1 family and has a broad range in inducing cellular changes affecting fibrosis and inflammatory responses. Pathological effects of Fosl-2 have been associated with systemic sclerosis (SSc). In addition, increased expression of Fosl-2 has been detected in human SSc monocyte-derived macrophages [1]. Monocytes and macrophages play a central role in activating and propagating acute inflammation followed by pathological fibrosis and organ dysfunction. The classification of the macrophage polarization phenotype can be assigned based on the stimulus, for example into classically-activated M(LPS), and alternatively-activated M(IL-4) macrophages [2]. However, the role of the Fosl-2 transcription factor in macrophage polarization remains elusive.Objectives:To investigate the role of Fosl-2 in macrophage polarization in SSc using Fosl-2 overexpressing transgenic (Fosl-2 tg) mice and human blood-derived macrophages from SSc patients.Methods:Thiogylcolate-elicited peritoneal macrophages were isolated from wild-type (wt) and Fosl-2 tg mice. Human peripheral CD14+ blood-derived monocytes were isolated and differentiated to macrophages (hMDM) from healthy controls and SSc patients. Murine and human macrophages were polarized with LPS (10 ng/ml), LPS + recombinant mouse IFN-γ (10 ng/ml), recombinant mouse, resp. human IL-4 (10 ng/ml) or remained untreated. Macrophage surface marker expression was assessed by flow cytometry using a mouse (F4/80, CD11b, CD86, CD80, CD38, MHCII, CD206, PD-L1, PD-L2, CD36) or human (CD38, CD40, CD86, PD-L2, PD-L1, CD163, CD206) designed polarization panel. Phagocytic activity was detected with pHrodo Red E.coli particles by flow cytometry. Gene expression and secretion of pro- and anti-inflammatory markers were measured by RT-qPCR, standard ELISAs and Griess Assay for nitric oxide production.Results:After LPS stimulation, mRNA levels of IL-1β (p<0.01, n=11-12), TNF-α (p=0.05, n=11-12) and IFN-γ (p<0.05, n=7) were reduced, whereas expression of IL-10 (p<0.05, n=11-12) was enhanced in Fosl-2 tg peritoneal macrophages in comparison to wt cells. Secretion of TNF-α (p<0.01, n=9-11) and nitric oxide (p<0.01, n=9) was impaired in Fosl-2 tg peritoneal macrophages compared to wt cells after LPS stimulation. Peritoneal macrophages were analyzed directly after isolation for macrophage polarization cell surface marker expression. Fosl-2 tg peritoneal macrophages showed an increase in the F4/80+CD11b+PD-L2+CD36+ cell population (p<0.01, n=3-6) compared to peritoneal macrophages from wt mice.The expression of cell surface markers of non-polarized and IL-4 stimulated SSc hMDM (n=17) showed an increased percentage of CD40+CD86+CD206+PD-L2+CD163+ cells (p<0.05) compared to healthy control hMDM (n=7). Phagocytic activity was enhanced in SSc hMDM (n=7) compared to healthy untreated (p<0.05), LPS (p=0.05) and IL-4 (p<0.05) hMDM (n=5).Conclusion:Our animal data indicates a role of Fosl-2 in regulating macrophage polarization with a shift from a classically-activated to an alternatively-activated phenotype. Similarly, SSc hMDM resemble a functional M(IL-4) alternative macrophage phenotype.Thus, maintaining a balanced proportion of classically- and alternatively-activated macrophage phenotypes may be an effective tool to control macrophage function in SSc.References:[1]Moreno-Moral, A., et al., Changes in macrophage transcriptome associate with systemic sclerosis and mediate GSDMA contribution to disease risk. Ann Rheum Dis, 2018. 77(4): p. 596-601.[2]Kania, G., M. Rudnik, and O. Distler, Involvement of the myeloid cell compartment in fibrogenesis and systemic sclerosis. Nat Rev Rheumatol, 2019. 15(5): p. 288-302.Disclosure of Interests:Amela Hukara: None declared, Michal Rudnik: None declared, Chantal Brigitta Rufer: None declared, Oliver Distler Speakers bureau: Actelion, Bayer, Boehringer Ingelheim, Medscape, Novartis, Roche, Menarini, Mepha, MSD, iQone, Pfizer, Consultant of: Abbvie, Actelion, Acceleron Pharma, Amgen, AnaMar, Arxx Therapeutics, Bayer, Baecon Discovery, Blade Therapeutics, Boehringer, CSL Behring, ChemomAb, Corpuspharma, Curzion Pharmaceuticals, Ergonex, Galapagos NV, GSK, Glenmark Pharmaceuticals, Inventiva, Italfarmaco, iQvia, Kymera, Medac, Medscape, Mitsubishi Tanabe Pharma, MSD, Roche, Sanofi, UCB, Lilly, Target BioScience, Pfizer, Grant/research support from: Actelion, Bayer, Boehringer Ingelheim, Kymera Therapeutics, Mitsubishi Tanabe, Przemyslaw Blyszczuk: None declared, Gabriela Kania: None declared


2019 ◽  
Vol 20 (10) ◽  
pp. 2474 ◽  
Author(s):  
Jonathan Yap ◽  
Hector A. Cabrera-Fuentes ◽  
Jason Irei ◽  
Derek J. Hausenloy ◽  
William A. Boisvert

Cardiovascular diseases are the leading cause of mortality worldwide. It is widely known that non-resolving inflammation results in atherosclerotic conditions, which are responsible for a host of downstream pathologies including thrombosis, myocardial infarction (MI), and neurovascular events. Macrophages, as part of the innate immune response, are among the most important cell types in every stage of atherosclerosis. In this review we discuss the principles governing macrophage function in the healthy and infarcted heart. More specifically, how cardiac macrophages participate in myocardial infarction as well as cardiac repair and remodeling. The intricate balance between phenotypically heterogeneous populations of macrophages in the heart have profound and highly orchestrated effects during different phases of myocardial infarction. In the early “inflammatory” stage of MI, resident cardiac macrophages are replaced by classically activated macrophages derived from the bone marrow and spleen. And while the macrophage population shifts towards an alternatively activated phenotype, the inflammatory response subsides giving way to the “reparative/proliferative” phase. Lastly, we describe the therapeutic potential of cardiac macrophages in the context of cell-mediated cardio-protection. Promising results demonstrate innovative concepts; one employing a subset of yolk sac-derived, cardiac macrophages that have complete restorative capacity in the injured myocardium of neonatal mice, and in another example, post-conditioning of cardiac macrophages with cardiosphere-derived cells significantly improved patient’s post-MI diagnoses.


2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Chitra Rawat ◽  
Samiksha Kukal ◽  
Ujjwal Ranjan Dahiya ◽  
Ritushree Kukreti

Abstract Epilepsy, a common multifactorial neurological disease, affects about 69 million people worldwide constituting nearly 1% of the world population. Despite decades of extensive research on understanding its underlying mechanism and developing the pharmacological treatment, very little is known about the biological alterations leading to epileptogenesis. Due to this gap, the currently available antiepileptic drug therapy is symptomatic in nature and is ineffective in 30% of the cases. Mounting evidences revealed the pathophysiological role of neuroinflammation in epilepsy which has shifted the focus of epilepsy researchers towards the development of neuroinflammation-targeted therapeutics for epilepsy management. Markedly increased expression of key inflammatory mediators in the brain and blood-brain barrier may affect neuronal function and excitability and thus may increase seizure susceptibility in preclinical and clinical settings. Cyclooxygenase-2 (COX-2), an enzyme synthesizing the proinflammatory mediators, prostaglandins, has widely been reported to be induced during seizures and is considered to be a potential neurotherapeutic target for epilepsy management. However, the efficacy of such therapy involving COX-2 inhibition depends on various factors viz., therapeutic dose, time of administration, treatment duration, and selectivity of COX-2 inhibitors. This article reviews the preclinical and clinical evidences supporting the role of COX-2 in seizure-associated neuroinflammation in epilepsy and the potential clinical use of COX-2 inhibitors as a future strategy for epilepsy treatment.


2002 ◽  
Vol 283 (6) ◽  
pp. E1123-E1134 ◽  
Author(s):  
Itzhak Nissim ◽  
Oksana Horyn ◽  
Yevgeny Daikhin ◽  
Ilana Nissim ◽  
Adam Lazarow ◽  
...  

Administration of arginine or a high-protein diet increases the hepatic content of N-acetylglutamate (NAG) and the synthesis of urea. However, the underlying mechanism is unknown. We have explored the hypothesis that agmatine, a metabolite of arginine, may stimulate NAG synthesis and, thereby, urea synthesis. We tested this hypothesis in a liver perfusion system to determine 1) the metabolism ofl-[ guanidino-15N2]arginine to either agmatine, nitric oxide (NO), and/or urea; 2) hepatic uptake of perfusate agmatine and its action on hepatic N metabolism; and 3) the role of arginine, agmatine, or NO in regulating NAG synthesis and ureagenesis in livers perfused with15N-labeled glutamine and unlabeled ammonia or15NH4Cl and unlabeled glutamine. Our principal findings are 1) [ guanidino-15N2]agmatine is formed in the liver from perfusatel-[ guanidino-15N2]arginine (∼90% of hepatic agmatine is derived from perfusate arginine); 2) perfusions with agmatine significantly stimulated the synthesis of 15N-labeled NAG and [15N]urea from 15N-labeled ammonia or glutamine; and 3) the increased levels of hepatic agmatine are strongly correlated with increased levels and synthesis of 15N-labeled NAG and [15N]urea. These data suggest a possible therapeutic strategy encompassing the use of agmatine for the treatment of disturbed ureagenesis, whether secondary to inborn errors of metabolism or to liver disease.


2021 ◽  
Vol 12 ◽  
Author(s):  
Natália S. Vellozo ◽  
Thaís S. Rigoni ◽  
Marcela F. Lopes

In the innate immunity to Leishmania infection tissue-resident macrophages and inflammatory monocytes accumulate host-cell, effector, and efferocytosis functions. In addition, neutrophils, as host, effector, and apoptotic cells, as well as tissue-resident and monocyte-derived dendritic cells (DCs) imprint innate and adaptive immunity to Leishmania parasites. Macrophages develop phenotypes ranging from antimicrobial M1 to parasite-permissive M2, depending on mouse strain, Leishmania species, and T-cell cytokines. The Th1 (IFN-γ) and Th2 (IL-4) cytokines, which induce classically-activated (M1) or alternatively-activated (M2) macrophages, underlie resistance versus susceptibility to leishmaniasis. While macrophage phenotypes have been well discussed, new developments addressed the monocyte functional phenotypes in Leishmania infection. Here, we will emphasize the role of inflammatory monocytes to access how potential host-directed therapies for leishmaniasis, such as all-trans-retinoic acid (ATRA) and the ligand of Receptor Activator of Nuclear Factor-Kappa B (RANKL) might modulate immunity to Leishmania infection, by directly targeting monocytes to develop M1 or M2 phenotypes.


2019 ◽  
Author(s):  
Fangjia Tong ◽  
Siwei Zhang ◽  
Huanhuan Xie ◽  
Bingqing Yan ◽  
Lianhao Song ◽  
...  

AbstractHuman papillomavirus (HPV) is an etiological risk factor for a subset of head and neck squamous cell carcinoma (HNSCC). HPV+ HNSCC is significant more radiosensitive than HPV-HNSCC, but the underlying mechanism is still unknown. Tumor microenvironment can affect tumor response to radiation therapy. Cancer secreted exosomes are emerging as crosstalk mediators between tumor cells and the tumor microenvironment. The main objectives of this study were to determine the role of HPV+ HNSCC-derived exosomes in increased radiation sensitivity. Here, we found that exosomes derived from HPV+ HNSCC cells activate macrophages into the M1 phenotype, which then increases the radiosensitivity of HNSCC cells. miR-9 was enriched in exosomes released from HPV+ HNSCC cells and it could be transported to macrophages, leading to altered cellular functions. Overexpression of miR-9 in macrophages induced polarization into the M1 phenotype via downregulation of PPARδ. Increased radiosensitivity was observed for HNSCC cells co-cultured with macrophages in which miR-9 was upregulated or treated with M1 macrophages. These observations suggest that HPV+ HNSCC cells secrete miR-9-rich exosomes, which then polarize macrophages into M1 phenotype and lead to increased radiosensitivity of HNSCC cells. Hence, miR-9 may be a potential treatment strategy for HNSCC.Statement of significanceHPV+ HNSCC through the release of miR-9-rich exosomes polarize macrophages into M1 phenotype and lead to increased radiosensitivity of HNSCC.


2021 ◽  
Vol 1 (4) ◽  
pp. 260-272
Author(s):  
Priyanka Mishra ◽  
Nikhil Pandey ◽  
Ratna Pandey ◽  
Yamini B Tripathi

Acute Respiratory Distress Syndrome is a familiar and destructive clinical condition characterized by progressive, swift and impaired pulmonary state. It leads to mortality if not managed in a timely manner. Recently the role of imbalanced macrophage polarization has been reported in ARDS. Macrophages are known for their heterogeneity and plasticity. Under different microenvironmental stimuli, they (M0) can switch between classically activated macrophage (M1) and alternatively activated (M2) states. This switch is regulated by several signaling pathways and epigenetic changes. In this review, the importance of macrophage M1 and M2 has been discussed in the arena of ARDS citing the phase-wise impact of macrophage polarization. This will provide a further understanding of the molecular mechanism involved in ARDS and will help in developing novel therapeutic targets. Various biomarkers that are currently used concerning this pathophysiological feature have also been summarized.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaonan Qiu ◽  
Lin Zheng ◽  
Xiuting Liu ◽  
Dan Hong ◽  
Mintong He ◽  
...  

Psoriasis is a common inflammatory skin disease resulting from an interplay of keratinocytes and immune cells. Previous studies have identified an essential role of autophagy in the maintenance of epidermal homeostasis including proliferation and differentiation. However, much less is known about the role of autophagy-related proteins in the cutaneous immune response. Herein, we showed that ULK1, the key autophagic initiator, and its phosphorylation at Ser556 were distinctively decreased in the epidermis from lesional skin of psoriasis patients. Topical application of SBI0206965, a selective ULK1 inhibitor, significantly attenuated epidermal hyperplasia, infiltration of neutrophils, and transcripts of the psoriasis-related markers in imiquimod (IMQ)-induced psoriasiform dermatitis (PsD). In vitro, ULK1 impairment by siRNA and SBI0206965 arrested cell proliferation and promoted apoptosis of keratinocytes but had a marginal effect on the expression of proinflammatory mediators under steady status. Surprisingly, SBI0206965 blocked the production of chemokines and cytokines in keratinocytes stimulated by neutrophils. Of interest, the pro-apoptotic and anti-inflammatory effects of ULK1 inhibition cannot be fully replicated by autophagic inhibitors. Our findings suggest a self-regulatory process by downregulating ULK1 to maintain the immune homeostasis of psoriatic skin via regulating keratinocytes and their crosstalk with neutrophils, possibly through both autophagy-dependent and independent mechanisms. ULK1 might be a potential target for preventing or treating psoriasis.


2015 ◽  
Vol 24 (2) ◽  
pp. 203-213 ◽  
Author(s):  
Federica Furfaro ◽  
Cristina Bezzio ◽  
Sandro Ardizzone ◽  
Alessandro Massari ◽  
Roberto De Franchis ◽  
...  

The treatment of ulcerative colitis (UC) has changed over the last decade. It is extremely important to optimize the therapies which are available nowadays and commonly used in daily clinical practice, as well as to stimulate the search for more powerful drugs for the induction and maintenance of sustained and durable remission, thus preventing further complications. Therefore, it is mandatory to identify the patients' prognostic variables associated with an aggressive clinical course and to test the most potent therapies accordingly.To date, the conventional therapeutic approach based on corticosteroids, salicylates (sulfasalazine, 5-aminosalicylic acid) or immunosuppressive agents is commonly used as a first step to induce and to maintain remission. However, in recent years, knowledge of new pathogenetic mechanisms of ulcerative colitis have allowed us to find new therapeutic targets leading to the development of new treatments that directly target proinflammatory mediators, such as TNF-alpha, cytokines, membrane migration agents, cellular therapies.The aim of this review is to provide the most significant data regarding the therapeutic role of drugs in UC and to give an overview of biological and experimental drugs that will become available in the near future. In particular, we will analyse the role of these drugs in the treatment of acute flare and maintenance of UC, as well as its importance in mucosal healing and in treating patients at a high risk of relapse.


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