scholarly journals Magnetically-Targeted Nanoparticle-Guided M2 Macrophage Polarization For Fracture Healing Promotion

Author(s):  
Wu Zhou ◽  
Ze Lin ◽  
Yuan Xiong ◽  
Hang Xue ◽  
Wen Song ◽  
...  

Abstract Background: Macrophages are essential for fracture healing, acting mainly through remodeling of the extracellular matrix and promotion of angiogenesis. The role of macrophages in regulating osteogenic differentiation, particularly that of the M2 phenotype, is increasingly researched. Baicalein (BCL) had also been shown to have pro-fracture-healing effects.Results: In this study, we developed mesoporous silica and Fe3O4 composite-targeted nanoparticles loaded with BCL (BCL@MMSNPs-SS-CD-NW), that could be magnetically delivered to the fracture site. These induced macrophage recruitment in a targeted manner, polarizing them towards the M2 phenotype, and thereby inducing MSCs towards osteoblastic differentiation. The mesoporous silicon nanoparticles (MSNs) were prepared with surface sulfhydrylation and amination modification, and the mesoporous channels were blocked with β-cyclodextrin. The outer layer of the mesoporous silicon was added with an amantane-modified NW targeting peptide to obtain the targeted nano-system. After entering macrophages, BCL could be released from nanoparticles since the disulfide linker could be cleaved by intracellular glutathione (GSH) resulting in the removing of CD gatekeeper, which is a key element in the pro-bone-remodeling functions, such as anti-inflammation and induction of M2 macrophage polarization to facilitate osteogenic differentiation.Conclusions: This nano-system passively accumulated in the fracture site, promoting osteogenic differentiation activities, highlighting a potent therapeutic benefit with high biosafety.

2016 ◽  
Vol 36 (4) ◽  
Author(s):  
Yan Zhong ◽  
Chun Yi

Macrophages are highly plastic cells with the ability to differentiate into both M1- and M2-polarized phenotypes. As a distinct M2-polarized population, tumour-associated macrophages (TAMs) promote tumorigenesis owing to their pro-angiogenic and immune-suppressive functions in tumour microenvironment. In the present study, we found that the microRNA-720 (miR-720) was down-regulated in TAMs isolated from breast carcinomas and M2-polarization macrophages. Overexpression of miR-720 attenuated M2 phenotype expression and thus inhibited M2 polarization. We further identified GATA binding protein 3 (GATA3), a transcriptional factor that plays an important role in M2 macrophage polarization, was the downstream target of miR-720. Ectopic expression of GATA3 restored the M2 phenotype in miR-720 overexpressed macrophages. Importantly, overexpression of miR-720 inhibited pro-migration behaviour and phagocytic ability of M2-polarized macrophages. Thus, our data suggest that miR-720 plays an important role in regulating M2 macrophage polarization and function.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1303 ◽  
Author(s):  
Alexandra Pritchard ◽  
Sultan Tousif ◽  
Yong Wang ◽  
Kenneth Hough ◽  
Saad Khan ◽  
...  

Cellular cross-talk within the tumor microenvironment (TME) by exosomes is known to promote tumor progression. Tumor promoting macrophages with an M2 phenotype are suppressors of anti-tumor immunity. However, the impact of tumor-derived exosomes in modulating macrophage polarization in the lung TME is largely unknown. Herein, we investigated if lung tumor-derived exosomes alter transcriptional and bioenergetic signatures of M0 macrophages and polarize them to an M2 phenotype. The concentration of exosomes produced by p53 null H358 lung tumor cells was significantly reduced compared to A549 (p53 wild-type) lung tumor cells, consistent with p53-mediated regulation of exosome production. In co-culture studies, M0 macrophages internalized tumor-derived exosomes, and differentiated into M2 phenotype. Importantly, we demonstrate that tumor-derived exosomes enhance the oxygen consumption rate of macrophages, altering their bioenergetic state consistent with that of M2 macrophages. In vitro co-cultures of M0 macrophages with H358 exosomes demonstrated that exosome-induced M2 polarization may be p53 independent. Murine bone marrow cells and bone marrow-derived myeloid-derived suppressor cells (MDSCs) co-cultured with lewis lung carcinoma (LLC)-derived exosomes differentiated to M2 macrophages. Collectively, these studies provide evidence for a novel role for lung tumor-exosomes in M2 macrophage polarization, which then offers new therapeutic targets for immunotherapy of lung cancer.


Author(s):  
Yunhua Peng ◽  
Qingyuan Wang ◽  
Wei Yang ◽  
Qiqi Yang ◽  
Ynani Pei ◽  
...  

Herein, we unfolded miR-98-5p mechanism in inflammatory bowel disease (IBD). IBD mouse model was established. The severity of colitis was assessed daily using the disease activity index (DAI). Murine peritoneal macrophages were stimulated by lipopolysaccharide (LPS). MiR-98-5p, tribbles homolog 1 (Trib1), M1 and M2 macrophage marker genes mRNA expression was analyzed. The relationship between miR-98-5p and Trib1 was explored using a luciferase reporter assay. The strategy of loss-of-function was used to explore the mechanism of miR-98-5p in macrophage polarization, inflammation and IBD. The results revealed that IBD mice had higher DAI index and miR-98-5p expression when compared to the Sham group. MiR-98-5p and Trib1 displayed a targeted regulation relationship. Knockdown of miR-98-5p transformed LPS-induced M1 macrophage polarization into M2 macrophage polarization and inhibited inflammation via up-regulating Trib1. However, shTrib1 reversed the effects. In vivo experiment, silencing of miR-98-5p, diminished the DAI and promoted M2 macrophage polarization. In conclusion, knockdown of miR-98-5p changed macrophage polarization to the M2 phenotype by increasing Trib1 expression, thereby alleviating IBD symptoms.


2021 ◽  
Vol 22 (3) ◽  
pp. 1109
Author(s):  
Paulina Kazimierczak ◽  
Malgorzata Koziol ◽  
Agata Przekora

Chronic immune response to bone implant may lead to delayed healing and its failure. Thus, newly developed biomaterials should be characterized by high biocompatibility. Moreover, it is well known that macrophages play a crucial role in the controlling of biomaterial-induced inflammatory response. Immune cells synthesize also a great amount of signaling molecules that regulate cell differentiation and tissue remodeling. Non-activated macrophages (M0) may be activated (polarized) into two main types of macrophage phenotype: proinflammatory type 1 macrophages (M1) and anti-inflammatory type 2 macrophages (M2). The aim of the present study was to assess the influence of the newly developed chitosan/agarose/nanohydroxyapatite bone scaffold (Polish Patent) on the macrophage polarization and osteogenic differentiation. Obtained results showed that macrophages cultured on the surface of the biomaterial released an elevated level of anti-inflammatory cytokines (interleukin-4, -10, -13, transforming growth factor-beta), which is typical of the M2 phenotype. Moreover, an evaluation of cell morphology confirmed M2 polarization of the macrophages on the surface of the bone scaffold. Importantly, in this study, it was demonstrated that the co-culture of macrophages-seeded biomaterial with bone marrow-derived stem cells (BMDSCs) or human osteoblasts (hFOB 1.19) enhanced their osteogenic ability, confirming the immunomodulatory effect of the macrophages on the osteogenic differentiation process. Thus, it was proved that the developed biomaterial carries a low risk of inflammatory response and induces macrophage polarization into the M2 phenotype with osteopromotive properties, which makes it a promising bone scaffold for regenerative medicine applications.


Author(s):  
Roberta F.J. Criado ◽  
Paulo Ricardo Criado ◽  
Carla Pagliari ◽  
Mirian N. Sotto ◽  
Carlos D'Apparecida Machado Filho ◽  
...  

Author(s):  
Yuting Tang ◽  
Xiaofang Lin ◽  
Cheng Chen ◽  
Zhongyi Tong ◽  
Hui Sun ◽  
...  

Background: Nucleolin has multiple functions within cell survival and proliferation pathways. Our previous studies have revealed that nucleolin can significantly reduce myocardial ischemia-reperfusion injury by promoting myocardial angiogenesis and reducing myocardial apoptosis. In this study, we attempted to determine the role of nucleolin in myocardial infarction (MI) injury recovery and the underlying mechanism. Methods: Male BALB/c mice aged 6–8 weeks were used to set up MI models by ligating the left anterior descending coronary artery. Nucleolin expression in the heart was downregulated by intramyocardial injection of a lentiviral vector expressing nucleolin-specific small interfering RNA. Macrophage infiltration and polarization were measured by real-time polymerase chain reaction, flow cytometry, and immunofluorescence. Cytokines were detected by enzyme-linked immunosorbent assay. Results: Nucleolin expression in myocardium after MI induction decreased a lot at early phase and elevated at late phase. Nucleolin knockdown impaired heart systolic and diastolic functions and decreased the survival rate after MI. Macrophage infiltration increased in the myocardium after MI. Most macrophages belonged to the M1 phenotype at early phase (2 days) and the M2 phenotype increased greatly at late phase after MI. Nucleolin knockdown in the myocardium led to a decrease in M2 macrophage polarization with no effect on macrophage infiltration after MI. Furthermore, Notch3 and STAT6, key regulators of M2 macrophage polarization, were upregulated by nucleolin in RAW 264.7 macrophages. Conclusions: Lack of nucleolin impaired heart function during recovery after MI by reducing M2 macrophage polarization. This finding probably points to a new therapeutic option for ischemic heart disease.


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