Macrophages In Microenvironment Research Articles

Zhuyu Pills promote polarization of macrophages toward M2 phenotype to prevent atherosclerosis via PPARγ/NF-κB signaling pathway

This article aims to investigate the effect of Zhuyu Pills on atherosclerosis and decipher the underlying mechanism. The mouse model of atherosclerosis was induced by a high-fat diet, and the total modeling period was 12 weeks. A total of 47 ApoE~(-/-) mice successfully modeled were randomized into 5 groups, including 10 in the model group, 9 in each of low-, medium-, and high-dose(130.54, 261.08 and 522.16 mg·kg~(-1)·d~(-1), respectively) Zhuyu Pills groups, and 10 in the atorvastatin calcium(10.40 mg·kg~(-1)·d~(-1)) group. In addition, 10 C57BL/6J mice were included as the normal group. The mice in the normal group and model group were administrated with an equal volume of sterile distilled water, and those in other groups with corresponding agents by gavage once a day for 12 weeks. At the end of drug intervention, the levels of total cholesterol(TC), triglyceride(TG), high-density lipoprotein cholesterol(HDL-C), and low-density lipoprotein cholesterol(LDL-C) were measured by the biochemical method. Hematoxylin-eosin(HE) staining was employed to observe the plaque distribution in the aortic region. The serum levels of pro-inflammatory cytokines tumor necrosis factor-α(TNF-α) and interleukin(IL)-6 in M1 macrophages and anti-inflammatory cytokines IL-13 and IL-4 in M2 macrophages were determined by enzyme-linked immunosorbent assay(ELISA). The expression levels of inducible nitric oxide synthase(iNOS) and arginase-1(Arg-1) were examined by immunofluorescence. Real-time fluorescence quantitative polymerase chain reaction(real-time PCR) was employed to measure the mRNA levels of peroxisome proliferator-activated receptor γ(PPARγ), nuclear factor-κB(NF-κB), Arg-1, and iNOS in the aorta. Western blot was employed to determine the protein levels of PPARγ and NF-κB in the aorta. The results showed that compared with the normal group, the modeling elevated the TC, TG, and LDL-C levels, lowered the HDL-C level, caused large area thickening of the aortic intima, elevated the TNF-α and IL-6 levels, lowered the IL-4 and IL-13 levels, down-regulated the mRNA and protein levels of PPARγ and Arg-1, and up-regulated the mRNA and protein levels of iNOS and NF-κB in the aorta(P<0.01). Compared with the model group, low-, medium-, and high-dose Zhuyu Pills and atorvastatin calcium lowered the TC, TG, and LDL-C levels, elevated the HDL-C level, reduced the plaque area in a concentration-dependent manner, lowered the TNF-α and IL-6 levels, elevated the IL-4 and IL-13 levels, up-regulated the mRNA and protein levels of PPARγ and Arg-1, and down-regulated the mRNA and protein levels of NF-κB and iNOS in the aorta(P<0.05 or P<0.01). In conclusion, Zhuyu Pills may play an anti-atherosclerosis role by regulating PPARγ/NF-κB signaling pathway, inhibiting the polarization of macrophages toward the M1 phenotype, promoting the polarization of macrophages toward the M2 phenotype, and improving the inflammatory microenvironment of macrophages.

Long Noncoding RNA Metastasis-Associated Lung Adenocarcinoma Transcript 1 Promotes HIV-1 Replication through Modulating microRNAs in Macrophages.

Macrophages can serve as a reservoir for human immunodeficiency-1 (HIV-1) virus in host cells, constituting a barrier to eradication, even in patients who are receiving antiretroviral therapy. Although many noncoding RNAs have been characterized as regulators in HIV-1/AIDS-induced immune response and pathogenesis, only a few long noncoding RNAs (lncRNAs) have demonstrated a close association with HIV-1 replication, and the molecular mechanisms remain unknown. In this study, we investigated how lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), related microRNAs, and key inflammatory genes alter HIV-1 replication in macrophages. Our data show that HIV-1 infection modulates the expression of miR-155 and miR-150-5p in a time-dependent manner, which is regulated by MALAT1. MALAT1 induced suppressor of cytokine signaling 1 (SOCS1) expression by sponging miR-150-5p in HIV-1-infected macrophages and stimulated inflammatory mediators triggering receptor expressed on myeloid cells/cold inducible RNA binding protein (TREM 1/CIRP) ligand/receptor. The RNA immunoprecipitation (RIP) assay validated the direct interaction within the MALAT1/miR-150-5p/SOCS1 axis. HIV-1 infection-mediated upregulation of MALAT1, SOCS1, and HIV-1 Gag was attenuated by SN50 (an NF-кB p50 inhibitor). MALAT1 antisense oligonucleotides (ASOs) suppressed HIV-1 p24 production and HIV-1 Gag gene expression and decreased expression of miR-155 and SOCS1, as well as the production of proinflammatory cytokines by HIV-1-infected macrophages. In conclusion, HIV-1 infection induces MALAT1, which attenuates miR-150-5p expression and increases SOCS1 expression, promoting HIV-1 replication and reactivation. These data provide new insights into how MALAT1 alters the macrophage microenvironment and subsequently promotes viral replication and suggest a potential role for targeting MALAT1 as a therapeutic approach to eliminate HIV-1 reservoirs. IMPORTANCE Viral reservoirs constitute an obstacle to curing HIV-1 diseases, despite antiretroviral therapy. Macrophages serve as viral reservoirs in HIV infection by promoting long-term replication and latency. Recent studies have shown that lncRNAs can modulate virus-host interactions, but the underlying mechanisms are not fully understood. In this study, we demonstrate how lncRNA MALAT1 contributes to HIV-1 replication through modulation of the miR-150/SOCS1 axis in human macrophages. Our findings have the potential to identify new therapies for eliminating HIV-1 reservoirs in immune cells.

β-catenin inhibition in tumor microenvironment macrophages promotes immunogenicity

Abstract Melanoma cells activate Wnt/β-catenin signaling in the tumor microenvironment (TME) to promote tumor progression and suppress dendritic cell-mediated anti-tumor immunity. However, the role of β-catenin in macrophages and its effect on anti-tumor immunity is largely undefined. In this study, using XAV939, a tankyrase inhibitor encapsulated in nanoparticles, we explored whether targeting β-catenin in macrophages can promote immunogenicity in TME. Our data show that the co-culture of macrophages with melanoma cell supernatants or melanoma cells in the presence of XAV939 nanoparticles significantly promotes the expression of CD80 and CD86, and suppresses the expression of PD-L1 and CD206 compared to macrophages treated with control nanoparticles. Similarly, XAV939 nanoparticle treatment of macrophages in co-culture conditions resulted in significantly increased TNF-α and IL-6 and reduced IL-10 production by macrophages compared to control groups. Our data suggest that targeted inhibition of β-catenin in tumor associated macrophages could overcome tolerance and promote anti-tumor immunity.

Prognostic value of macrophage vasculiform mimicry in the evaluation of uveal melanoma progression

Introduction Uveal melanoma (UM) is a malignant neoplasm of the vascular tract of the eye, prone to hematogenous metastasis, regardless of the type of treatment performed. Prediction and probability of UM metastasis is one of the main tasks of onco-ophthalmology. We decribed an alternative method of tumor blood supply due to the process of vasculo-like mimicry (VM) with the formation of pseudovascular structures of tumor cells is described. At the same time, the participation of the microenvironment in the processes of VM and metastasis is currently debatable and relevant.Purpose of the work was to evaluate the prognostic role of macrophage vasculiform mimicry in the progression of chorioid melanoma based on the histological and immunohistochemical characteristics of surgical material.Materials and methods The surgical material of choroidal melanoma after enucleation for the period 2013-2018 was studied. Histological, histochemical (PAS reaction) and immunohistochemical studies were carried out using markers CD68 (macrophages), CD 34, CD31, D2-40 for the purpose of qualitative and quantitative assessment of macrophages in the stroma of tumors, large vessels and pseudovessels in the tumor.Results The ability of macrophages to form vasculo-like spaces in choroidal melanoma has been discovered and described. In growth with macrometastases, more phage representatives are recorded than in tissue samples of non-metastasizing melanoma. the volume of the macroscopic mass of the ulcer and the growth rate of phages were registered as the inverse average in terms of the strength of the correlation. In group studies with metastases, an increase in the volume of pseudovascular volumes and the number of phages is recorded.Discussion The macrophage microenvironment in a tumor can play a dual role: antitumor and protumor. The ability of macrophages for VM in UM has been described. The results of our macrostudy confirm the protumor activity of phages and their important role in tumor metastasis.Conclusion In-depth study of the ways of pseudovascular space formation not only by the cells of the tumor itself, but also by its microenvironment, helps to open new directions in the study of predictors of UM metastasis and outline approaches to the development of new directions of anti-tumortherapy.

Differences in responses to the intracellular macrophage environment between Mycobacterium bovis BCG vaccine strains Moreau and Pasteur.

The Bacille Calmette-Guérin (BCG) vaccine comprises a family of strains with variable protective efficacy against pulmonary tuberculosis (TB) and leprosy, partly due to genetic differences between strains. Previous data highlighting differences between the genomes and proteomic profiles of BCG strains Moreau and Pasteur led us to evaluate their behaviour in the macrophage microenvironment, capable of stimulating molecular responses that can impact the protective effect of the vaccine. Strain infectivity, viability, co-localisation with acidified vesicles, macrophage secretion of IL-1 and MCP-1 and lipid droplet biogenesis were evaluated after infection. We found that BCG Moreau is internalised more efficiently, with significantly better intracellular survival up to 96 h p.i., whereas more BCG Pasteur bacilli were found co-localised in acidified vesicles up to 6 h p.i. IL-1β and MCP-1 secretion and lipid droplet biogenesis by infected macrophages were more prominent in response to BCG Pasteur. Overall, our results show that, compared to Pasteur, BCG Moreau has increased fitness and better endurance in the harsh intracellular environment, also regulating anti-microbial responses (lower IL-1b and MCP-1). These findings contribute to the understanding of the physiology of BCG Moreau and Pasteur in response to the intraphagosomal environment in a THP-1 macrophage model.

Influence of the Immune Microenvironment Provided by Implanted Biomaterials on the Biological Properties of Masquelet-Induced Membranes in Rats: Metakaolin as an Alternative Spacer.

Macrophages play a key role in the inflammatory phase of wound repair and foreign body reactions-two important processes in the Masquelet-induced membrane technique for extremity reconstruction. The macrophage response depends largely on the nature of the biomaterials implanted. However, little is known about the influence of the macrophage microenvironment on the osteogenic properties of the induced membrane or subsequent bone regeneration. We used metakaolin, an immunogenic material, as an alternative spacer to standard polymethylmethacrylate (PMMA) in a Masquelet model in rats. Four weeks after implantation, the PMMA- and metakaolin-induced membranes were harvested, and their osteogenic properties and macrophage microenvironments were investigated by histology, immunohistochemistry, mass spectroscopy and gene expression analysis. The metakaolin spacer induced membranes with higher levels of two potent pro-osteogenic factors, transforming growth factor-β (TGF-β) and bone morphogenic protein-2 (BMP-2). These alternative membranes thus had greater osteogenic activity, which was accompanied by a significant expansion of the total macrophage population, including both the M1-like and M2-like subtypes. Microcomputed tomographic analysis showed that metakaolin-induced membranes supported bone regeneration more effectively than PMMA-induced membranes through better callus properties (+58%), although this difference was not significant. This study provides the first evidence of the influence of the immune microenvironment on the osteogenic properties of the induced membranes.

Dysfunction of macrophages leads to diabetic bone regeneration deficiency

Insufficient bone matrix formation caused by diabetic chronic inflammation can result in bone nonunion, which is perceived as a worldwide epidemic, with a substantial socioeconomic and public health burden. Macrophages in microenvironment orchestrate the inflammation and launch the process of bone remodeling and repair, but aberrant activation of macrophages can drive drastic inflammatory responses during diabetic bone regeneration. In diabetes mellitus, the proliferation of resident macrophages in bone microenvironment is limited, while enhanced myeloid differentiation of hematopoietic stem cells (HSCs) leads to increased and constant monocyte recruitment and thus macrophages shift toward the classic pro-inflammatory phenotype, which leads to the deficiency of bone regeneration. In this review, we systematically summarized the anomalous origin of macrophages under diabetic conditions. Moreover, we evaluated the deficit of pro-regeneration macrophages in the diabetic inflammatory microenvironment. Finally, we further discussed the latest developments on strategies based on targeting macrophages to promote diabetic bone regeneration. Briefly, this review aimed to provide a basis for modulating the biological functions of macrophages to accelerate bone regeneration and rescue diabetic fracture healing in the future.

Injectable immunomodulation-based porous chitosan microspheres/HPCH hydrogel composites as a controlled drug delivery system for osteochondral regeneration

The inappropriate regenerated fibrous cartilage and subchondral bone of the injured chondral defect ultimately cause degeneration of the regenerated cartilage, which eventually leads to the failure of cartilage repair. In this study, we developed a macrophage-modulated and injectable ‘building block’ drug delivery system comprised of porous chitosan (CS) microspheres and hydroxypropyl chitin (HPCH) hydrogel, where the dimethyloxallyl glycine (DMOG) was encapsulated in the thermosensitive HPCH hydrogel (HD) while kartogenin (KGN) was conjugated on the porous CS microspheres (CSK-PMS). The developed HD/CSK-PMS composite scaffold effectively modulated the microenvironment at the defect site, achieved local macrophage M2 polarization and promoted cartilage regeneration. The fast-degradable HD favored hyaline cartilage regeneration, while the highly stable CSK-PMS supported the endochondral ossification and regenerated the subchondral bone. In vitro and in vivo evaluations revealed that the newly developed HD/CSK-PMS as a controlled drug delivery system could effectively create M2 macrophage microenvironment and orchestrate osteochondral (OC) regeneration. These findings indicate the importance of the immune microenvironment and subchondral bone for high-quality cartilage repair, and thus the immunomodulation-based hydrogel/PMS composite system could be a promising candidate for OC regeneration.

Lactate metabolism coordinates macrophage response and regeneration in zebrafish.

Rationale: Macrophages are multifunctional cells with a pivotal role on tissue development, homeostasis and regeneration. Indeed, in response to tissue injury and the ensuing regeneration process, macrophages are challenged and undergo massive metabolic adaptations and changes. However, the control of this metabolic reprogramming by macrophage microenvironment has never been deciphered in vivo.Methods: In this study, we used zebrafish model and caudal fin resection as a robust regeneration system. We explored specific changes in gene expression after tissue amputation via single-cell RNA sequencing analysis and whole-tissue transcriptomic analysis. Based on the identification of key modifications, we confirmed the role of the lactate pathway in macrophage response and fin regeneration, through the combination of chemical and genetic inhibitors of this pathway.Results: Single cell RNA sequencing revealed the upregulation of different genes associated with glycolysis and lactate metabolism in macrophages, upon fin regeneration. Hence, using chemical inhibitors of the LDH enzyme, we confirmed the role of lactate in macrophage recruitment and polarization, to promote a pro-inflammatory phenotype and enhance fin regeneration. The genetic modulation of monocarboxylate transporters illustrated a complex regulation of lactate levels, based on both intracellular and extracellular supplies. Commonly, the different sources of lactate resulted in macrophage activation with an increased expression level of inflammatory cytokines such as TNFa during the first 24 hours of regeneration. Transcriptomic analyses confirmed that lactate induced a global modification of gene expression in macrophages.Conclusion: Altogether, our findings highlight the crucial role of lactate at the onset of macrophage differentiation toward a pro-inflammatory phenotype. The deep modifications of macrophage phenotype mediated by lactate and downstream effectors play a key role to coordinate inflammatory response and tissue regeneration.

The effects of different stimulated macrophages on HaCaT proliferation and secretion.

Background-As an important cell of innate immunity, macrophages secrete a large number of inflammatory cytokines, including TNF-α, which may play crucial role in the initiation stage of psoriatic inflammation. Keratinocytes are the effector cells of psoriasis and may produce circulatory stimulation networks with other immune cells in the lesions. Understanding the effect of macrophages induce keratinocytes’ biological function is necessary to understand the mechanisms of psoriasis. Objectives-To evaluate the effects of different polarized macrophages on the proliferation, differentiation, apoptosis and secretion of immortalized human keratinocytes (HaCaT). Materials and Methods-Establish co-culture system of macrophages and HaCaT in vitro to mimic macrophage infiltration microenvironment of psoriasis skin. The proliferation of HaCaT was detectd by CCK8, Cell cycle. Apoptosis of HaCaT was analysed by flow cytometry. The secretion of IL-1β, TNF and IL-6 by HaCaT was analysed by ELISA. Results-The results showed a decreased proliferation of HaCaT when co-cultured with LPS-induced macrophage and upregulated IL-6, IL-1β and TNF-α. While more HaCaT cells were blocked in the G0/G1 phase, the number of mitotic phase cells decreased and apoptotic cells increased. On the contrast, HaCaT showed increased proliferation when co-cultured with IL-4-induced macrophage, while no difference in apotosis of HaCaT. Moreover, proinflammatory cytokine TNF-α and IL-12 production by LPS-induced macrophage were significantly increased. Conclusion-Considering the changes in the biological function of HaCaT cells caused by the infiltration microenvironment of macrophages, these findings indicate that the polarization process of macrophage is a crucial mechanism in the development of psoriasis, and the underlying immunological mechanisms should be understood.

Macrophage Plasticity and Atherosclerosis Therapy.

Atherosclerosis is a chronic disease starting with the entry of monocytes into the subendothelium and the subsequent differentiation into macrophages. Macrophages are the major immune cells in atherosclerotic plaques and are involved in the dynamic progression of atherosclerotic plaques. The biological properties of atherosclerotic plaque macrophages determine lesion size, composition, and stability. The heterogenicity and plasticity of atherosclerotic macrophages have been a hotspot in recent years. Studies demonstrated that lipids, cytokines, chemokines, and other molecules in the atherosclerotic plaque microenvironment regulate macrophage phenotype, contributing to the switch of macrophages toward a pro- or anti-atherosclerosis state. Of note, M1/M2 classification is oversimplified and only represent two extreme states of macrophages. Moreover, M2 macrophages in atherosclerosis are not always protective. Understanding the phenotypic diversity and functions of macrophages can disclose their roles in atherosclerotic plaques. Given that lipid-lowering therapy cannot completely retard the progression of atherosclerosis, macrophages with high heterogeneity and plasticity raise the hope for atherosclerosis regression. This review will focus on the macrophage phenotypic diversity, its role in the progression of the dynamic atherosclerotic plaque, and finally discuss the possibility of treating atherosclerosis by targeting macrophage microenvironment.

Identification of immune microenvironment subtypes that predicted the prognosis of patients with ovarian cancer.

Ovarian cancer (OC) is associated with high mortality rate. However, the correlation between immune microenvironment and prognosis of OC remains unclear. This study aimed to explore prognostic significance of OC tumour microenvironment. The OC data set was selected from the cancer genome atlas (TCGA), and 307 samples were collected. Hierarchical clustering was performed according to the expression of 756 genes. The immune and matrix scores of all immune subtypes were determined, and Kruskal‐Wallis test was used to analyse the differences in the immune and matrix scores between OC samples with different immune subtypes. The model for predicting prognosis was constructed based on the expression of immune‐related genes. TIDE platform was applied to predict the effect of immunotherapy on patients with OC of different immune subtypes. The 307 OC samples were classified into three immune subtypes A‐C. Patients in subtype B had poorer prognosis and lower survival rate. The infiltration of helper T cells and macrophages in microenvironment indicated significant differences between immune subtypes. Enrichment analyses of immune cell molecular pathways showed that JAK–STAT3 pathway changed significantly in subtype B. Furthermore, predictive response to immunotherapy in subtype B was significantly higher than that in subtype A and C. Immune subtyping can be used as an independent predictor of the prognosis of OC patients, which may be related to the infiltration patterns of immune cells in tumour microenvironment. In addition, patients in immune subtype B have superior response to immunotherapy, suggesting that patients in subtype B are suitable for immunotherapy.

The nanomaterial-induced bystander effects reprogrammed macrophage immune function and metabolic profile

Bystander effects in biological systems are the responses shown by nontargeted neighboring cells, and critical to the bio-nano interface interactions. In addition to direct effects, bystander effects also determine the design, applications and safety of nanomaterials, although the related information of nanomaterial-induced bystander effects remain largely unknown. A coculture system of A549 and THP-1 was established to mimic the lung microenvironment to study the bystander effects of WS2 nanosheets (representative transition-metal dichalcogenide nanosheets) on microenvironment macrophages during the inhalation exposure or the nanomaterial biomedical application in the lung. Lung cells exposed to WS2 nanosheet resulted in an increase in reactive oxygen species and the depolarization of mitochondrial membrane potential in neighboring macrophages. Bystander exposure also induced macrophage polarization toward the anti-inflammatory M2 phenotype, which is adverse to disease therapy. Metabolomics showed that WS2 nanosheets disturbed the energy metabolism and amino acid metabolism of macrophages, consistent with the metabolic characteristics of M2 macrophages. Nitric oxide-transforming growth factor-β1 played an important mediator in the bystander effects. Importantly, WS2 nanosheet bystander exposure affected macrophage phagocytosis and migration and altered the macrophage immune response to endotoxin. This study improves the current understanding of bio-nano interactions and highlights the importance of neighboring cell responses, allowing us to use the maximum benefits of nanomaterials while limiting their adverse bystander effects.

Functional Implications of Cathelicidin Antimicrobial Protein in Breast Cancer and Tumor-Associated Macrophage Microenvironment.

It is well-established that tumor-associated macrophages (TAMs) play an important role in breast cancer development. Accumulating evidence suggested that human cathelicidin antimicrobial protein (CAMP), which is mainly expressed in host defense cells such as macrophages, is crucial not only in combating microorganisms but also promoting tumor growth. Here we report the interaction of CAMP with TAMs in breast cancer. CAMP expression was upregulated in cancer tissues and in the circulation of breast cancer patients. Surgical removal of tumor decreased CAMP peptide serum level. Knockdown of CAMP decreased cell proliferation and migration/invasion ability in breast cancer cells. CAMP expression was altered during macrophage M1/M2 polarization and was expressed predominantly in M2 phenotype. In addition, breast cancer cells co-cultured with macrophages upregulated CAMP expression and also increased cancer cell viability. Xenograft tumors reduced significantly upon CAMP receptor antagonist treatment. Our data implicated that CAMP confers an oncogenic role in breast cancer and plays an important role in the tumor microenvironment between TAMs and breast cancer cells, and blocking the interaction between them would provide a novel therapeutic option for this malignant disease.

Metabolomic Characterization of Metabolic Disturbances in the Extracellular Microenvironment of Oleate-Treated Macrophages Using Gas Chromatography–Mass Spectrometry

Abnormal extracellular microenvironment signals of macrophages contribute to the occurrence and progression of metabolic diseases. Macrophage metabolism is a therapeutic target for treating metabolic diseases. However, molecular mechanisms of metabolic disturbances in the extracellular microenvironment of macrophages remain unclear. Here, an untargeted metabolomics approach based on gas chromatography–mass spectrometry revealed significant metabolic disturbances in the extracellular microenvironment of oleate-treated macrophages. Most of above changes were responsive to resveratrol and/or pioglitazone intervention. Notably, the concentration levels of most saccharides and lactate were increased in the extracellular microenvironment of the oleate-treated macrophages. The increased levels of fructose and lactate were abolished by resveratrol and/or pioglitazone treatment. Additionally, the concentrations of isoleucine and metabolites derived from branched-chain amino acids (including 4-methyl-2-oxovalerate, 3-methyl-2-oxobutanoate, and 3-methyl-2-oxovalerate) were increased in the extracellular microenvironment of the oleate-treated macrophages. These effects were alleviated or abolished by both resveratrol and pioglitazone treatments. Moreover, myristate and oleate accumulated in the extracellular microenvironment of the oleate-treated macrophages. The metabolic disturbances in the extracellular microenvironment of oleate-treated macrophages indicated carbohydrate metabolism, glycolysis, branched-chain amino acid metabolism and fatty acid metabolism as potential therapeutic targets for treating metabolic diseases and the intervention effects of resveratrol and pioglitazone. To the best of our knowledge, this study is the first to demonstrate the accumulation of saccharides, lactate, isoleucine and branched-chain amino acid-derived metabolites in the extracellular microenvironment of macrophages.

Rhinovirus-induced IFN\u03b2 expression is NF\u03baB-dependent and regulated by the macrophage microenvironment

Macrophages play an important role in asthma pathogenesis both in the inflammatory and resolution phase of the disease. Macrophages can acquire different polarisation states dependent on their microenvironment. It is yet unclear through which mechanism the microenvironment affects the anti-viral response in macrophages. We hypothesized that the macrophage microenvironment regulates rhinovirus-induced IFNβ expression. Murine bone marrow-derived monocytes and human differentiated THP-1 cells were stimulated with M-CSF or GM-CSF and IFNγ or IL-4/IL-13, respectively, to mimic a Th1 or Th2 environment. Macrophages were infected with rhinovirus and gene and protein levels of IFNβ and pattern recognition receptor expression were measured. In subsequent experiments an IκB kinase inhibitor was used to study the involvement of NFκB. Both murine and human M1-like macrophages exhibited higher levels of IFNβ and pattern recognition receptors after rhinovirus infection than M2-like macrophages. Blockage of NFκB resulted in a lower expression of rhinovirus-induced IFNβ in human M1-like macrophages while inducing a higher expression in M2-like macrophages, suggesting that the interferon response towards viral infection was mediated by NFκB. These findings could contribute to a better understanding of mechanisms causing reduced anti-viral responses at viral-induced exacerbations in asthma.

Macrophages confer resistance to PI3K inhibitor GDC-0941 in breast cancer through the activation of NF-\u03baB signaling

The PI3K pathway is one of the most dysregulated signaling pathways in epithelial cancers and has become an attractive therapeutic target under active preclinical and clinical development. However, recent clinical trial studies revealed that blockade of PI3K activity in advanced cancer often leads to the development of resistance and relapse of the diseases. Intense efforts have been made to elucidate resistance mechanisms and identify rational drug combinations with PI3K inhibitors in solid tumors. In the current study, we found that PI3K inhibition by GDC-0941 increased macrophage infiltration and induced the expression of macrophage-associated cytokines and chemokines in the mouse 4T1 breast tumor model. Using the in vitro co-culture system, we showed that the presence of macrophages led to the activation of NF-κB signaling in 4T1 tumor cells, rendering tumor cells resistant to PI3K inhibition by GDC-0941. Furthermore, we found that Aspirin could block the activation of NF-κB signaling induced by PI3K inhibition, and combined use of GDC-0941 and Aspirin resulted in attenuated cell growth and enhanced apoptosis of 4T1 cells in the in vitro co-culture system with the presence of macrophages. Consistently, the combination treatment also effectively reduced tumor burden, macrophage infiltration and pulmonary metastasis in in vivo 4T1 breast tumor model. Together, our results suggested macrophages in microenvironment may contribute to the resistance of breast cancer cells to PI3K inhibition and reveal a new combination paradigm to improve the efficacy of PI3K-targeted therapy.

Engineering mechanical microenvironment of macrophage and its biomedical applications.

Macrophages are the most plastic cells in the hematopoietic system and can be widely found in almost all tissues. Recently studies have shown that mechanical cues (e.g., matrix stiffness and stress/strain) can significantly affect macrophage behaviors. Although existing reviews on the physical and mechanical cues that regulate the macrophage's phenotype are available, engineering mechanical microenvironment of macrophages in vitro as well as a comprehensive overview and prospects for their biomedical applications (e.g., tissue engineering and immunotherapy) has yet to be summarized. Thus, this review provides an overview on the existing methods for engineering mechanical microenvironment of macrophages in vitro and then a section on their biomedical applications and further perspectives are presented.

Oligo-Fucoidan prevents IL-6 and CCL2 production and cooperates with p53 to suppress ATM signaling and tumor progression

Low-molecular-weight Fucoidan (Oligo-Fucoidan) is a sulfated polysaccharide that has a variety of biological effects and has also been shown to have beneficial health effects. However, the molecular mechanisms underlying the therapeutic effects of Oligo-Fucoidan in patients with cancer remain unclear. Using human colorectal cancer HCT116 cells with (p53+/+) or without (p53−/−) normal p53 expression, we found that Oligo-Fucoidan treatment reduces the occurrence of spontaneous DNA lesions. Etoposide induces double strand DNA breaks. Subsequent administration of Oligo-Fucoidan to etoposide-treated cells promotes p53 accumulation, p21 expression and significant decreases in ataxia-telangiectasia-mutated (ATM), checkpoint kinase 1 (Chk1) and γ-H2AX phosphorylation in p53+/+ cells compared with p53−/− cells. Similarly, co-administration of Oligo-Fucoidan with etoposide inhibits ATM, Chk1 and γ-H2AX phosphorylation, particularly in the presence of p53. Furthermore, Oligo-Fucoidan supplementation increases cancer cell death and attenuates the adverse effects induced by etoposide that decreases production of the pro-inflammatory cytokine IL-6 and chemokine CCL2/MCP-1. Importantly, Oligo-Fucoidan decreases the tumor-promoting M2 macrophages in microenvironment as well as collaborates with p53 and works in combination with etoposide to prevent HCT116 tumorigenicity. Our results first demonstrate that p53 enables Oligo-Fucoidan to effectively inhibit tumor progression, and Oligo-Fucoidan minimizes the side effects of chemotherapy and alters tumor microenvironment.

VEGFR3 inhibition chemosensitizes lung adenocarcinoma A549 cells in the tumor-associated macrophage microenvironment through upregulation of p53 and PTEN.

In lung adenocarcinoma, loss of p53 and PTEN in tumors are associated with decreased response to chemotherapy and decreased survival. A means to pharmacologically upregulate p53 and PTEN protein expression could improve the prognosis of patients with p53- and PTEN-deficient tumors. In the present study we revealed that vascular endothelial growth factor receptor 3 (VEGFR3) inhibition in lung adenocarcinoma cells was associated with improved expression levels of both p53 and PTEN in the tumor-associated macrophage (TAM) microenvironment. Inhibition of VEGFR3 in lung adenocarcinoma cells was associated with growth arrest and decreased migration and invasion. The upregulation of p53 and PTEN protein expression after VEGFR3 inhibition decreased chemotherapy resistance and improved chemosensitivity in co-cultured A549 cells in which p53 and PTEN expression were decreased. Finally, we demonstrated that TAMs promoted the expression of VEGF-C and its receptor VEGFR3. Western blot analysis revealed the co-cultured A549 cells with TAMs are a primary source of VEGF-C and VEGFR3 in the tumor microenvironment. Our studies revealed that VEGFR3 inhibition may be a pharmacological means to upregulate p53 and PTEN protein expression and improve the outcome of patients with p53- and PTEN-deficient tumors.