scholarly journals Melittin Regulates Iron Homeostasis as a Key Mediator of Macrophage Polarization in Rat Lumbar Spinal Stenosis

2021 ◽  
Author(s):  
Hyunseong Kim ◽  
Jin Young Hong ◽  
Wan-Jin Jeon ◽  
Junseon Lee ◽  
Yoon Jae Lee ◽  
...  
Keyword(s):  
Spinal Stenosis ◽  
Iron Metabolism ◽  
Iron Homeostasis ◽  
Macrophage Polarization ◽  
M2 Macrophages ◽  
Iron Release ◽  
Locomotor Recovery ◽  
Lumbar Spinal

Abstract BackgroundLumbar spinal stenosis (LSS) is defined as the narrowing of the spinal canal, which compresses the nerves traveling through the lower back into the legs. Inflammation is the most common cause of LSS. Chronic pain induced by nerve damage results from chronic inflammation, and the inflammation response worsens with elevated iron stores. Furthermore, macrophage polarization to the M1 (inflammatory) or M2 (anti-inflammatory) type is essential for controlling host defense or repairing tissues. However, the precise function of macrophage polarization in iron release or retention in LSS pathophysiology is not well-understood. Here, we introduce melittin to modulate macrophage polarization related to iron metabolism for LSS treatment.MethodsPrimary peritoneal macrophage were cultured in 200 or 500 ng/mL of melittin and FeSO4-containing medium for 24 h. Macrophage polarization was assessed by Immunofluorescence staining to CD86 or Arg1 antibodies. In an in vivo rat model of LSS, melittin were administered at 100 and 250 µg/kg, and in vivo effects of melittin on iron deposition-induced macrophage polarization was evaluated by immunochemistry, real time-PCR, western blot, and flow-cytometry. The locomotor functions were assessed by BBB, ladder scoring, and Von Frey test for up to 3 weeks. ResultsIn vitro experiments demonstrated that macrophages can be polarized toward an M2 phenotype after melittin treatment in iron-insulted primary macrophages. Treatment with 100 and 250 μg/kg melittin in a rat LSS model increased the proportion of M2 macrophages in the damaged spinal cord. Moreover, we found that melittin attenuated iron overload-induced M1 polarization via regulating iron metabolism-related genes in LSS rats. As a result, melittin improved locomotor recovery and stimulated axonal growth following LSS.ConclusionsMelittin can promote functional recovery in LSS models by activating M2 macrophages via controlling macrophage iron metabolism, suggesting the potential applications of melittin for treating LSS.

scholarly journals Montelukast, a Cysteinyl Leukotriene Receptor 1 Antagonist, Induces M2 Macrophage Polarization and Inhibits Murine Aortic Aneurysm Formation

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Yohei Kawai ◽  
Yuji Narita ◽  
Aika Yamawaki-Ogata ◽  
Akihiko Usui ◽  
Kimihiro Komori
Keyword(s):  
Aortic Aneurysm ◽  
Macrophage Polarization ◽  
Enzyme Linked Immunosorbent Assay ◽  
M2 Macrophage ◽  
M2 Macrophages ◽  
Gene Expressions ◽  
Arginase 1 ◽  
M2 Macrophage Polarization

Background. The pathogenesis of abdominal aortic aneurysm (AAA) is characterized by atherosclerosis with chronic inflammation in the aortic wall. Montelukast is a selective cys-LT 1 receptor antagonist that can suppress atherosclerotic diseases. We evaluated the in vitro properties of montelukast and its in vivo activities in an angiotensin II–infused apolipoprotein E–deficient (apoE−/−) AAA mouse model. Methods. The mouse monocyte/macrophage cell line J774A.1 was used in vitro. M1 macrophages were treated with montelukast, and gene expressions of inflammatory cytokines were measured. Macrophages were cultured with montelukast, then gene expressions of arginase-1 and IL (interleukin)-10 were assessed by quantitative polymerase chain reaction, arginase-1 was measured by fluorescence-activated cell sorting, and IL-10 concentration was analyzed by enzyme-linked immunosorbent assay. In vivo, one group (Mont, n=7) received oral montelukast (10 mg/kg/day) for 28 days, and the other group (Saline, n=7) was given normal Saline as a control for the same period. Aortic diameters, activities of matrix metalloproteinases (MMPs), cytokine concentrations, and the number of M2 macrophages were analyzed. Results. Relative to control, montelukast significantly suppressed gene expressions of MMP-2, MMP-9, and IL-1β, induced gene expressions of arginase-1 and IL-10, enhanced the expression of the arginase-1 cell surface protein, and increased the protein concentration of IL-10. In vivo, montelukast significantly decreased aortic expansion (Saline vs Mont; 2.44 ± 0.15 mm vs 1.59 ± 0.20 mm, P<.01), reduced MMP-2 activity (Saline vs Mont; 1240 μM vs 755 μM, P<.05), and induced infiltration of M2 macrophages (Saline vs Mont; 7.51 % vs 14.7 %, P<.05). Conclusion. Montelukast induces M2 macrophage polarization and prevents AAA formation in apoE−/− mice.

scholarly journals Three-Dimensionally Printed Ti2448 With Low Stiffness Enhanced Angiogenesis and Osteogenesis by Regulating Macrophage Polarization via Piezo1/YAP Signaling Axis

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhen Tang ◽  
Xinghui Wei ◽  
Tian Li ◽  
Hao Wu ◽  
Xin Xiao ◽  
...  
Keyword(s):  
Bone Repair ◽  
Macrophage Polarization ◽  
Stress Shielding ◽  
Biological Properties ◽  
Future Application ◽  
M2 Macrophages ◽  
Low Elastic Modulus ◽  
Signaling Axis

Previous studies have found that the novel low-elastic-modulus Ti2448 alloy can significantly reduce stress shielding and contribute to better bone repair than the conventional Ti6Al4V alloy. In this study, the promotion of osteogenesis and angiogenesis by three-dimensionally printed Ti2448 were also observed in vivo. However, these were not significant in a series of in vitro tests. The stiffness of materials has been reported to greatly affect the response of macrophages, and the immunological regulation mediated by macrophages directly determines the fate of bone implants. Therefore, we designed more experiments to explore the role of three-dimensionally printed Ti2448 in macrophage activation and related osteogenesis and angiogenesis. As expected, we found a significant increase in the number of M2 macrophages around Ti2448 implants, as well as better osteogenesis and angiogenesis in vivo. In vitro studies also showed that macrophages pre-treated with Ti2448 alloy significantly promoted angiogenesis and osteogenic differentiation through increased PDGF-BB and BMP-2 secretion, and the polarization of M2 macrophages was enhanced. We deduced that Ti2448 promotes angiogenesis and osteogenesis through Piezo1/YAP signaling axis-mediated macrophage polarization and related cytokine secretion. This research might provide insight into the biological properties of Ti2448 and provide a powerful theoretical supplement for the future application of three-dimensionally printed Ti2448 implants in orthopaedic surgery.

scholarly journals Iron Overload contributes to General Anesthesia-induced Neurotoxicity and Cognitive Deficits

2019 ◽  
Author(s):  
Jing Wu ◽  
Shuofei Yang ◽  
Yan Cao ◽  
Huihui Li ◽  
Hongting Zhao ◽  
...  
Keyword(s):  
Iron Overload ◽  
General Anesthesia ◽  
Iron Metabolism ◽  
Cognitive Deficits ◽  
Hippocampal Neurons ◽  
Iron Homeostasis ◽  
Novel Therapy ◽  
The Impact

Abstract Background Increasing evidence suggests that exposure to general anesthesia (GA) could be detrimental to cognitive development in young subjects, and might also contribute to accelerated neurodegeneration in the elderly. Iron is essential for normal neuronal function and excess iron in brain is a hallmark of neuroinflammation and is implicated in several neurodegenerative diseases. However, the role of iron in GA-induced neurotoxicity and cognitive deficits has not been studied.Methods We used the primary hippocampal neurons and rodents including young rats and aged mice to examine whether GA impacts iron metabolism and whether the impact contributed to neuronal outcomes. In addition, a pharmacological suppression of iron metabolism was performed to explore the molecular mechanism underlying GAs-mediated iron overload in the brain.Results Our results demonstrated that GA, induced by intravenous ketamine or inhalational sevoflurane, disturbed iron homeostasis and caused iron overload in both in vitro hippocampal neuron culture and in vivo hippocampus. Interestingly, ketamine or sevoflurane-induced cognitive deficits, very likely, result from a novel regulated iron-dependent cell death, ferroptosis. Notably, iron chelator deferiprone attenuated the GA-induced mitochondrial dysfunctions, ferroptosis, and further cognitive deficits. Moreover, we found that GA-induced iron overload was activated by NMDAR-RASD1 signalling via DMT1 action in the brain.Conclusion We conclude that disturbed iron metabolism may be involved in the pathogenesis of GA-induced neurotoxicity and cognitive deficits. Our study provides new insights into a potential novel therapy for prevention in GA-associated neurological disorders.

scholarly journals Angelicin Alleviates Post-Trauma Osteoarthritis Progression by Regulating Macrophage Polarization via STAT3 Signaling Pathway

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhansong Tian ◽  
Fanchun Zeng ◽  
Chunrong Zhao ◽  
Shiwu Dong
Keyword(s):  
Side Effects ◽  
Macrophage Polarization ◽  
Critical Factor ◽  
Molecular Medicine ◽  
M2 Macrophages ◽  
Stat3 Pathway ◽  
M2 Polarization ◽  
Ifn Γ

Post-trauma osteoarthritis (PTOA) is the most common articular disease characterized by degeneration and destruction of articular cartilage (Bultink and Lems, Curr. Rheumatol Rep., 2013, 15, 328). Inflammatory response of local joint tissue induced by trauma is the most critical factor accelerating osteoarthritis (OA) progression (Sharma et al., 2019; Osteoarthritis. Cartilage, 28, 658–668). M1/M2 macrophages polarization and repolarization participates in local inflammation, which plays a major role in the progression of OA (Zhang et al., 2018; Ann. Rheum. Dis., 77, 1524–1534). The regulating effect of macrophage polarization has been reported as a potential therapy to alleviate OA progression. Synovitis induced by polarized macrophages could profoundly affect the chondrocyte and cartilage matrix (Zhang et al., 2018; Ann. Rheum. Dis., 77, 1524–1534). Generally, anti-inflammatory medications widely used in clinical practice have serious side effects. Therefore, we focus on exploring a new therapeutic strategy with fewer side effects to alleviate the synovitis. Angelicin (ANG) is traditional medicine used in various folk medicine. Previous studies have revealed that angelicin has an inhibitory effect on inflammation (Wei et al., 2016; Inflammation, 39, 1876–1882), tumor growth (Li et al., 2016; Oncology reports, 36, 3,504–3,512; Wang et al., 2017; Molecular Medicine Reports, 16, 5441–5449), DNA damage (Li et al., 2019; Exp. Ther. Med., 18, 1899–1906), and virus proliferation (Li et al., 2018; Front. Cell. Infect. Microbiol., 8, 178). But its specific effects on influencing the process of OA were rarely reported. In this study, the molecular mechanism of angelicin in vivo and in vitro was clearly investigated. Results showed that angelicin could regulate the M1/M2 ratio and function and alleviate the development of PTOA in the meanwhile. Bone marrow monocytes were isolated and induced by macrophage colony-stimulating factor (M-CSF), lipopolysaccharide (LPS) and interferon (IFN)-γ for M1 polarization and interleukin (IL)-4/IL-13 for M2 polarization. Subsequently, repolarization intervention was performed. The results indicate that angelicin can repolarize M1 toward M2 macrophages by upregulating the expression of CD9. Besides, angelicin can also protect and maintain M2 polarization in the presence of LPS/IFN-γ, and subsequently downregulate the expression of inflammatory mediators such as IL-1β and TNF-α. Mechanistically, angelicin can activate the p-STAT3/STAT3 pathway by conducting CD9/gp130 to repolarize toward M2 macrophages. These results suggest angelicin can alleviate the progression of OA by regulating M1/M2 polarization via the STAT3/p-STAT3 pathway. Therefore, angelicin may have a promising application and potential therapeutic value in OA clinical treatment.

scholarly journals Iron Overload contributes to General Anesthesia-induced Neurotoxicity and Cognitive Deficits

2020 ◽  
Author(s):  
Jing Wu ◽  
Jian-Jun Yang ◽  
Yan Cao ◽  
Huihui Li ◽  
Hongting Zhao ◽  
...  
Keyword(s):  
Iron Overload ◽  
General Anesthesia ◽  
Iron Metabolism ◽  
Cognitive Deficits ◽  
Hippocampal Neurons ◽  
Iron Homeostasis ◽  
The Impact ◽  
The Brain

Abstract Background: Increasing evidence suggests that multiple or long-time exposure to general anesthesia (GA) could be detrimental to cognitive development in young subjects, and might also contribute to accelerated neurodegeneration in the elderly. Iron is essential for normal neuronal function and excess iron in brain is implicated in several neurodegenerative diseases. However, the role of iron in GA-induced neurotoxicity and cognitive deficits remains elusive. Methods: We used the primary hippocampal neurons and rodents including young rats and aged mice to examine whether GA impacted iron metabolism and whether the impact contributed to neuronal outcomes. In addition, a pharmacological suppression of iron metabolism was performed to explore the molecular mechanism underlying GAs-mediated iron overload in the brain. Results: Our results demonstrated that GA, induced by intravenous ketamine or inhalational sevoflurane, disturbed iron homeostasis and caused iron overload in both in vitro hippocampal neuron culture and in vivo hippocampus. Interestingly, ketamine or sevoflurane-induced cognitive deficits, very likely, resulted from a novel iron-dependent regulated cell death, ferroptosis. Notably, iron chelator deferiprone attenuated the GA-induced mitochondrial dysfunction, ferroptosis, and further cognitive deficits. Moreover, we found that GA-induced iron overload was activated by NMDAR-RASD1 signalling via DMT1 action in the brain. Conclusion: We conclude that disturbed iron metabolism may be involved in the pathogenesis of GA-induced neurotoxicity and cognitive deficits. Our study provides new vision for consideration in GA-associated neurological disorders.

scholarly journals Hypoxic glioma-derived exosomes promote M2-like macrophage polarization by enhancing autophagy induction

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Jianye Xu ◽  
Jian Zhang ◽  
Zongpu Zhang ◽  
Zijie Gao ◽  
Yanhua Qi ◽  
...  
Keyword(s):  
Macrophage Polarization ◽  
Autophagy Induction ◽  
Antitumor Immunotherapy ◽  
Novel Biomarkers ◽  
And Migration ◽  
Immunosuppressive Microenvironment ◽  
Proliferation And Migration ◽  
Glioma Progression

AbstractExosomes participate in intercellular communication and glioma microenvironment modulation, but the exact mechanisms by which glioma-derived exosomes (GDEs) promote the generation of the immunosuppressive microenvironment are still unclear. Here, we investigated the effects of GDEs on autophagy, the polarization of tumor-associated macrophages (TAMs), and glioma progression. Compared with normoxic glioma-derived exosomes (N-GDEs), hypoxic glioma-derived exosomes (H-GDEs) markedly facilitated autophagy and M2-like macrophage polarization, which subsequently promoted glioma proliferation and migration in vitro and in vivo. Western blot and qRT-PCR analyses indicated that interleukin 6 (IL-6) and miR-155-3p were highly expressed in H-GDEs. Further experiments showed that IL-6 and miR-155-3p induced M2-like macrophage polarization via the IL-6-pSTAT3-miR-155-3p-autophagy-pSTAT3 positive feedback loop, which promotes glioma progression. Our study clarifies a mechanism by which hypoxia and glioma influence autophagy and M2-like macrophage polarization via exosomes, which could advance the formation of the immunosuppressive microenvironment. Our findings suggest that IL-6 and miR-155-3p may be novel biomarkers for diagnosing glioma and that treatments targeting autophagy and the STAT3 pathway may contribute to antitumor immunotherapy.

scholarly journals Loss of ferroportin induces memory impairment by promoting ferroptosis in Alzheimer’s disease

2021 ◽  
Author(s):  
Wen-Dai Bao ◽  
Pei Pang ◽  
Xiao-Ting Zhou ◽  
Fan Hu ◽  
Wan Xiong ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Memory Impairment ◽  
Iron Homeostasis ◽  
Critical Role ◽  
Gene Set Enrichment Analysis ◽  
Molecular Characteristics ◽  
Intracellular Iron

AbstractIron homeostasis disturbance has been implicated in Alzheimer’s disease (AD), and excess iron exacerbates oxidative damage and cognitive defects. Ferroptosis is a nonapoptotic form of cell death dependent upon intracellular iron. However, the involvement of ferroptosis in the pathogenesis of AD remains elusive. Here, we report that ferroportin1 (Fpn), the only identified mammalian nonheme iron exporter, was downregulated in the brains of APPswe/PS1dE9 mice as an Alzheimer’s mouse model and Alzheimer’s patients. Genetic deletion of Fpn in principal neurons of the neocortex and hippocampus by breeding Fpnfl/fl mice with NEX-Cre mice led to AD-like hippocampal atrophy and memory deficits. Interestingly, the canonical morphological and molecular characteristics of ferroptosis were observed in both Fpnfl/fl/NEXcre and AD mice. Gene set enrichment analysis (GSEA) of ferroptosis-related RNA-seq data showed that the differentially expressed genes were highly enriched in gene sets associated with AD. Furthermore, administration of specific inhibitors of ferroptosis effectively reduced the neuronal death and memory impairments induced by Aβ aggregation in vitro and in vivo. In addition, restoring Fpn ameliorated ferroptosis and memory impairment in APPswe/PS1dE9 mice. Our study demonstrates the critical role of Fpn and ferroptosis in the progression of AD, thus provides promising therapeutic approaches for this disease.

scholarly journals CBIO-10. REDUCED IRON EXPORT FUNCTIONS IN A CELL INTRINSIC MANNER TO DRIVE GLIOBLASTOMA GROWTH

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii17-ii17
Author(s):  
Katie Troike ◽  
Erin Mulkearns-Hubert ◽  
Daniel Silver ◽  
James Connor ◽  
Justin Lathia
Keyword(s):  
Tumor Cells ◽  
Iron Uptake ◽  
Iron Homeostasis ◽  
Iron Status ◽  
Tumor Grade ◽  
Hfe Gene ◽  
Iron Release ◽  
Female Patients ◽  
Cellular Iron

Abstract Glioblastoma (GBM), the most common primary malignant brain tumor in adults, is characterized by invasive growth and poor prognosis. Iron is a critical regulator of many cellular processes, and GBM tumor cells have been shown to modulate expression of iron-associated proteins to enhance iron uptake from the surrounding microenvironment, driving tumor initiation and growth. While iron uptake has been the central focus of previous investigations, additional mechanisms of iron regulation, such as compensatory iron efflux, have not been explored in the context of GBM. The hemochromatosis (HFE) gene encodes a transmembrane glycoprotein that aids in iron homeostasis by limiting cellular iron release, resulting in a sequestration phenotype. We find that HFE is upregulated in GBM tumors compared to non-tumor brain and that expression of HFE increases with tumor grade. Furthermore, HFE mRNA expression is associated with significantly reduced survival specifically in female patients with GBM. Based on these findings, we hypothesize that GBM tumor cells upregulate HFE expression to augment cellular iron loading and drive proliferation, ultimately leading to reduced survival of female patients. To test this hypothesis, we generated Hfe knockdown and overexpressing mouse glioma cell lines. We observed significant alterations in the expression of several iron handling genes with Hfe knockdown or overexpression, suggesting global disruption of iron homeostasis. Additionally, we show that knockdown of Hfe in these cells increases apoptosis and leads to a significant impairment of tumor growth in vivo. These findings support the hypothesis that Hfe is a critical regulator of cellular iron status and contributes to tumor aggression. Future work will include further exploration of the mechanisms that contribute to these phenotypes as well as interactions with the tumor microenvironment. Elucidating the mechanisms by which iron effulx contributes to GBM may inform the development of next-generation targeted therapies.

scholarly journals Targeting Toll-Like Receptor 2: Polarization of Porcine Macrophages by a Mycoplasma-Derived Pam2cys Lipopeptide

Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 692
Author(s):  
Giulia Franzoni ◽  
Antonio Anfossi ◽  
Chiara Grazia De Ciucis ◽  
Samanta Mecocci ◽  
Tania Carta ◽  
...  
Keyword(s):  
Mhc Class Ii ◽  
Macrophage Polarization ◽  
Surface Protein ◽  
Antimicrobial Activities ◽  
Toll Like Receptor ◽  
Activation Markers ◽  
Class I Mhc ◽  
Toll Like Receptor 2

Toll-like receptor 2 (TLR2) ligands are attracting increasing attention as prophylactic and immunotherapeutic agents against pathogens and tumors. We previously observed that a synthetic diacylated lipopeptide based on a surface protein of Mycoplasma agalactiae (Mag-Pam2Cys) strongly activated innate immune cells, including porcine monocyte-derived macrophages (moMΦ). In this study, we utilized confocal microscopy, flow cytometry, multiplex cytokine ELISA, and RT-qPCR to conduct a comprehensive analysis of the effects of scalar doses of Mag-Pam2Cys on porcine moMΦ. We observed enhanced expression of activation markers (MHC class I, MHC class II DR, CD25), increased phagocytotic activity, and release of IL-12 and proinflammatory cytokines. Mag-Pam2Cys also upregulated the gene expression of several IFN-α subtypes, p65, NOS2, and molecules with antimicrobial activities (CD14, beta defensin 1). Overall, our data showed that Mag-Pam2Cys polarized porcine macrophages towards a proinflammatory antimicrobial phenotype. However, Mag-Pam2Cys downregulated the expression of IFN-α3, six TLRs (TLR3, -4, -5, -7, -8, -9), and did not interfere with macrophage polarization induced by the immunosuppressive IL-10, suggesting that the inflammatory activity evoked by Mag-Pam2Cys could be regulated to avoid potentially harmful consequences. We hope that our in vitro results will lay the foundation for the further evaluation of this diacylated lipopeptide as an immunopotentiator in vivo.

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