Effect of the Gc-derived macrophage-activating factor precursor (preGcMAF) on phagocytic activation of mouse peritoneal macrophages.

PubMed

Uto, Yoshihiro; Yamamoto, Syota; Takeuchi, Ryota; Nakagawa, Yoshinori; Hirota, Keiji; Terada, Hiroshi; Onizuka, Shinya; Nakata, Eiji; Hori, Hitoshi

2011-07-01

The 1f1f subtype of the Gc protein (Gc(1f1f) protein) was converted into Gc-derived macrophage-activating factor (GcMAF) by enzymatic processing in the presence of β-galactosidase of an activated B-cell and sialidase of a T-cell. We hypothesized that preGc(1f1f)MAF, the only Gc(1f1f) protein lacking galactose, can be converted to GcMAF in vivo because sialic acid is cleaved by residual sialidase. Hence, we investigated the effect of preGc(1f1f)MAF on the phagocytic activation of mouse peritoneal macrophages. We examined the sugar moiety of preGc(1f1f)MAF with a Western blot using peanut agglutinin (PNA) and Helix pomatia agglutinin (HPA) lectin. We also found that preGc(1f1f)MAF significantly enhanced phagocytic activity in mouse peritoneal macrophages but only in the presence of the mouse peritoneal fluid; the level of phagocytic activity was the same as that observed for GcMAF. PreGc(1f1f)MAF can be used as an effective macrophage activator in vivo.

Adrenomedullin Regulates IL-1β Gene Expression in F4/80+ Macrophages during Synovial Inflammation

PubMed Central

Takano, Shotaro; Miyagi, Masayuki; Inoue, Gen; Aikawa, Jun; Iwabuchi, Kazuya; Takaso, Masashi

2017-01-01

Adrenomedullin (AM) plays an important role in the regulation of inflammatory processes; however, the role and expression of AM in synovial inflammation have not been determined. To investigate the expression and role of AM in inflamed synovial tissue (ST), the gene expression profiles of AM in the ST, including synovial macrophages and fibroblasts, of a murine patellar surgical dislocation model were characterized. In addition, the effects of interleukin- (IL-) 1β and AM in cultured synovial cells were also examined. CD11c+ macrophages were found to be elevated in ST of the surgically dislocated patella. Higher gene expression of CD11c, IL-1β, AM, receptor activity-modifying proteins 2 (RAMP2), and 3 (RAMP3) was also observed in ST obtained from the dislocated side. AM expression was also significantly increased in synovial fibroblasts and macrophages in response to IL-1β treatment. Synovial macrophages also highly expressed RAMP3 compared to fibroblasts and this expression was further stimulated by exogenously added IL-1β. Further, the treatment of the F4/80-positive cell fraction obtained from ST with AM inhibited IL-1β expression. Taken together, these findings demonstrated that AM was produced by synovial fibroblasts and macrophages in inflamed ST and that increased levels of AM may exert anti-inflammatory effects on synovial macrophages. PMID:28299347

Nitric oxide synthase 2 is required for conversion of pro-fibrogenic inflammatory CD133(+) progenitors into F4/80(+) macrophages in experimental autoimmune myocarditis.

PubMed

Blyszczuk, Przemyslaw; Berthonneche, Corrine; Behnke, Silvia; Glönkler, Marcel; Moch, Holger; Pedrazzini, Thierry; Lüscher, Thomas F; Eriksson, Urs; Kania, Gabriela

2013-02-01

Experimental autoimmune myocarditis (EAM) model mirrors important mechanisms of inflammatory dilated cardiomyopathy (iDCM). In EAM, inflammatory CD133(+) progenitors are a major cellular source of cardiac myofibroblasts in the post-inflammatory myocardium. We hypothesized that exogenous delivery of macrophage-colony-stimulating factor (M-CSF) can stimulate macrophage lineage differentiation of inflammatory progenitors and, therefore, prevent their naturally occurring myofibroblast fate in EAM. EAM was induced in wild-type (BALB/c) and nitric oxide synthase 2-deficient (Nos2(-/-)) mice and CD133(+) progenitors were isolated from inflamed hearts. In vitro, M-CSF converted inflammatory CD133(+) progenitors into nitric oxide-producing F4/80(+) macrophages and prevented transforming growth factor-β-mediated myofibroblast differentiation. Importantly, only a subset of heart-infiltrating CD133(+) progenitors expresses macrophage-specific antigen F4/80 in EAM. These CD133(+)/F4/80(hi) cells show impaired myofibrogenic potential compared with CD133(+)/F4/80(-) cells. M-CSF treatment of wild-type mice with EAM at the peak of disease markedly increased CD133(+)/F4/80(hi) cells in the myocardium, and CD133(+) progenitors isolated from M-CSF-treated mice failed to differentiate into myofibroblasts. In contrast, M-CSF was not effective in converting CD133(+) progenitors from inflamed hearts of Nos2(-/-) mice into macrophages, and M-CSF treatment did not result in increased CD133(+)/F4/80(hi) cell population in hearts of Nos2(-/-) mice. Accordingly, M-CSF prevented post-inflammatory fibrosis and left ventricular dysfunction in wild-type but not in Nos2(-/-) mice. Active and NOS2-dependent induction of macrophage lineage differentiation abrogates the myofibrogenic potential of heart-infiltrating CD133(+) progenitors. Modulating the in vivo differentiation fate of specific progenitors might become a novel approach for the treatment of inflammatory heart diseases.

[A histological study and three-dimensional reconstruction of F4/80-positive reticular cells and macrophages at the onset of murine bone marrow hematopoiesis].

PubMed

Notsu, Eiji; Sonoda, Yuji; Sasaki, Kazunobu

2007-06-01

Adult bone marrow consists of two different compartments, a vascular compartment of sinusoid and a hematopoietic compartment consisting of stromal cells and hematopoietic cells. In the hematopoietic compartment, stromal cells play an important role in the formation of the microenvironment for hematopoiesis. To clarify the relationship between hematopoietic cells and stromal cells, particularly reticular cells and macrophages, we examined the femur bone marrow of ICR mouse fetuses and neonates using F4/80 immunostaining and three-dimensional reconstruction under light and electron microscopy. In the fetal femurs, the marrow cavity formed early from 15 days of gestation, and it showed a marked increase in volume thereafter. On the basis of the appearance of hematopoietic cells, marrow development could be classified into two stages, a pre-hematopoietic stage from 15 days of gestation to two days of age, and a beginning stage of hematopoiesis thereafter. The pre-hematopoietic bone marrow contains not only stromal reticular cells but also macrophages, and both types of stromal cells were strongly positive to F4/80 monoclonal antibody. These F4/80-positive reticular cells had a triangular cell profile with long and slender cytoplasmic processes. Reticular cells often contained large lysosomes of not only dying neutrophils but also erythroblast nuclei. A few erythroblasts accumulated around the processes, and the number of erythroblasts around reticular cells increased with bone marrow development. On the other hand, macrophages were located either close to sinusoids or in sinusoid lumen, and a close relationship to hematopoietic cells was hardly noticeable. At the beginning stage of hematopoiesis, F4/80-positive reticular cells extended their long and slender cytoplasmic processes, and the number and length of the processes appeared markedly increased. The three-dimensional cell surface of the F4/80-positive reticular cells became very complex. Numerous erythroblasts

Accumulation of M1-like macrophages in type 2 diabetic islets is followed by a systemic shift in macrophage polarization.

PubMed

Cucak, Helena; Grunnet, Lars Groth; Rosendahl, Alexander

2014-01-01

Human T2D is characterized by a low-grade systemic inflammation, loss of β-cells, and diminished insulin production. Local islet immunity is still poorly understood, and hence, we evaluated macrophage subpopulations in pancreatic islets in the well-established murine model of T2D, the db/db mouse. Already at 8 weeks of disease, on average, 12 macrophages were observed in the diabetic islets, whereas only two were recorded in the nondiabetic littermates. On a detailed level, the islet resident macrophages increased fourfold compared with nondiabetic littermates, whereas a pronounced recruitment (eightfold) of a novel subset of macrophages (CD68+F4/80-) was observed. The majority of the CD68+F4/80+ but only 40% of the CD68+F4/80- islet macrophages expressed CD11b. Both islet-derived macrophage subsets expressed moderate MHC-II, high galectin-3, and low CD80/CD86 levels, suggesting the cells to be macrophages rather than DCs. On a functional level, the vast majority of the macrophages in the diabetic islets was of the proinflammatory, M1-like phenotype. The systemic immunity in diabetic animals was characterized by a low-grade inflammation with elevated cytokine levels and increase of splenic cytokine, producing CD68+F4/80- macrophages. In late-stage diabetes, the cytokine signature changed toward a TGF-β-dominated profile, coinciding with a significant increase of galectin-3-positive macrophages in the spleen. In summary, our results show that proinflammatory M1-like galectin-3+ CD80/CD86(low) macrophages invade diabetic islets. Moreover, the innate immunity matures in a diabetes-dependent manner from an initial proinflammatory toward a profibrotic phenotype, supporting the concept that T2D is an inflammatory disease.

Macrophage origin limits functional plasticity in helminth-bacterial co-infection

PubMed Central

Campbell, Sharon M.; Duncan, Sheelagh; Hewitson, James P.; Barr, Tom A.; Jackson-Jones, Lucy H.; Maizels, Rick M.

2017-01-01

Rapid reprogramming of the macrophage activation phenotype is considered important in the defense against consecutive infection with diverse infectious agents. However, in the setting of persistent, chronic infection the functional importance of macrophage-intrinsic adaptation to changing environments vs. recruitment of new macrophages remains unclear. Here we show that resident peritoneal macrophages expanded by infection with the nematode Heligmosomoides polygyrus bakeri altered their activation phenotype in response to infection with Salmonella enterica ser. Typhimurium in vitro and in vivo. The nematode-expanded resident F4/80high macrophages efficiently upregulated bacterial induced effector molecules (e.g. MHC-II, NOS2) similarly to newly recruited monocyte-derived macrophages. Nonetheless, recruitment of blood monocyte-derived macrophages to Salmonella infection occurred with equal magnitude in co-infected animals and caused displacement of the nematode-expanded, tissue resident-derived macrophages from the peritoneal cavity. Global gene expression analysis revealed that although nematode-expanded resident F4/80high macrophages made an anti-bacterial response, this was muted as compared to newly recruited F4/80low macrophages. However, the F4/80high macrophages adopted unique functional characteristics that included enhanced neutrophil-stimulating chemokine production. Thus, our data provide important evidence that plastic adaptation of MΦ activation does occur in vivo, but that cellular plasticity is outweighed by functional capabilities specific to the tissue origin of the cell. PMID:28334040

Effects of murine leukemia virus env gene proteins on macrophage-mediated cytotoxicity in vitro

NASA Technical Reports Server (NTRS)

Chapes, S. K.; Takemoto, L. J.; Spooner, B. S. (Principal Investigator)

1991-01-01

F5b Tumor cells were incubated with concentrated culture supernatants taken from cells resistant (F5m) or sensitive (F5b) to contact-dependent macrophage cytotoxicity. Macrophage cell line B6MP102 and murine peritoneal macrophages killed targets incubated with supernatants taken from sensitive cells but poorly killed cells incubated in supernatants isolated from resistant cells. Membranes from cells resistant to macrophage killing, F5m, were fused into F5b cells. The fused F5b cells were killed significantly less than F5b cells fused with F5b cell membranes or untreated F5b cells. The decreased killing of F5b cells corresponded to increased concentrations of gp70(a) molecules on F5b cells. Affinity purified gp70(a) was added to cytotoxicity assays but failed to inhibit macrophage cytotoxicity. P15E molecules were detectable on both F5b and F5m cells. In addition, a synthetic peptide found to exhibit the inhibitory properties of p15E was added to cytotoxicity assays. P15E synthetic peptide also did not inhibit macrophage cytotoxicity. Therefore, env gene proteins of murine leukemia virus do not appear responsible for inducing tumor cell resistance to activated macrophage contact-dependent cytotoxicity.

Hyphal growth of phagocytosed Fusarium oxysporum causes cell lysis and death of murine macrophages.

PubMed

Schäfer, Katja; Bain, Judith M; Di Pietro, Antonio; Gow, Neil A R; Erwig, Lars P

2014-01-01

Fusarium oxysporum is an important plant pathogen and an opportunistic pathogen of humans. Here we investigated phagocytosis of F. oxysporum by J774.1 murine cell line macrophages using live cell video microscopy. Macrophages avidly migrated towards F. oxysporum germlings and were rapidly engulfed after cell-cell contact was established. F. oxysporum germlings continued hyphal growth after engulfment by macrophages, leading to associated macrophage lysis and escape. Macrophage killing depended on the multiplicity of infection. After engulfment, F. oxysporum inhibited macrophages from completing mitosis, resulting in large daughter cells fused together by means of a F. oxysporum hypha. These results shed new light on the initial stages of Fusarium infection and the innate immune response of the mammalian host.

Immunohistochemical characterisation of macrophages in human liver and gastrointestinal tract: expression of CD4, HLA-DR, OKM1, and the mature macrophage marker 25F9 in normal and diseased tissue.

PubMed

Hume, D A; Allan, W; Hogan, P G; Doe, W F

1987-11-01

This report describes the immunocytochemical characterisation of macrophages in sections of human liver, gastrointestinal tract, and associated lymphoid tissue and the inflammatory lesions of Crohn's disease. 25F9 is an antigen reported to be induced during the maturation of blood monocytes in vitro. The antigen was concentrated in cytoplasmic vesicular structures of isolated gastrointestinal macrophages. Similar labelled cells were observed in the apical regions of lamina propria in both small and large intestine in vivo. Their numbers and size were greatly increased in specimens of colon from patients with melanosis coli. Mucosal inflammatory lesions in specimens from patients with Crohn's disease did not contain 25F9-positive cells. The antigen was absent from giant cells and epithelioid cells in granulomata but was expressed on histiocytes in submucosal microgranulomata. In lymphoid organs, 25F9-positive cells were found in germinal centres, in the dome region of Peyer's patch, and in the medulla, but were largely excluded from T cell areas. In reactive nodes from Crohn's disease patients, the number of labelled cells in germinal centres and T cell areas was greatly increased. 25F9 was absent from the majority of typical liver Kupffer cells, but was expressed on cytoplasmic granules in a minor subpopulation of larger, more rounded cells in the liver. The results suggest that 25F9 is a marker for endocytosis rather than maturation. In parallel sections, resident macrophages of both liver and gastrointestinal tract labelled with Leu 3a/OKT4 (CD4) and with OKIa (HLA-DR antigen) but did not express OKM1 (type III complement receptor). By contrast, OKM1 was present on inflammatory cells, epithelioid cells, and giant cells in mucosal lesions of Crohn's disease.

Hyphal Growth of Phagocytosed Fusarium oxysporum Causes Cell Lysis and Death of Murine Macrophages

PubMed Central

Schäfer, Katja; Bain, Judith M.

2014-01-01

Fusarium oxysporum is an important plant pathogen and an opportunistic pathogen of humans. Here we investigated phagocytosis of F. oxysporum by J774.1 murine cell line macrophages using live cell video microscopy. Macrophages avidly migrated towards F. oxysporum germlings and were rapidly engulfed after cell-cell contact was established. F. oxysporum germlings continued hyphal growth after engulfment by macrophages, leading to associated macrophage lysis and escape. Macrophage killing depended on the multiplicity of infection. After engulfment, F. oxysporum inhibited macrophages from completing mitosis, resulting in large daughter cells fused together by means of a F. oxysporum hypha. These results shed new light on the initial stages of Fusarium infection and the innate immune response of the mammalian host. PMID:25025395

Terminal differentiation of murine resident peritoneal macrophages is characterized by expression of the STK protein tyrosine kinase, a receptor for macrophage-stimulating protein.

PubMed

Iwama, A; Wang, M H; Yamaguchi, N; Ohno, N; Okano, K; Sudo, T; Takeya, M; Gervais, F; Morissette, C; Leonard, E J; Suda, T

1995-11-01

STK, a new member of the hepatocyte growth factor receptor family, is the receptor for macrophage-stimulating protein (MSP), which acts on murine resident peritoneal macrophages. We established polyclonal and monoclonal antibodies against STK and characterized the structure of STK protein and STK expression on cells of the mononuclear phagocyte system. Western blotting showed that the STK transcript is translated into a single-chain precursor and then cleaved into a 165-kD disulfide-linked heterodimer composed of a 35-kD alpha-chain and a 144-kD beta-chain. Western blotting detected STK protein on resident peritoneal macrophages, a target of MSP, and showed that it was autophosphorylated in cells stimulated by MSP. By flow cytometric analysis using a monoclonal anti-STK antibody, we showed that STK protein is expressed on restricted macrophage populations such as resident peritoneal macrophages, but not on exudate peritoneal macrophages or mononuclear phagocytes of the bone marrow, peripheral blood, spleen, or alveoli. Resident peritoneal macrophages were classified into two fractions according to their reactivity with an anti-STK antibody and a marker antibody for macrophages: STKhigh-F4/80high cells and STKnegative-F4/80low cells. Acute exudative macrophages were all STKnegative-F4/80low, but they gradually became predominantly STKhigh-F4/80high several days after entrance into the peritoneal cavity. These results showed that after monocytes migrate into the peritoneal cavity, they undergo terminal differentiation in the peritoneal microenvironment. This is the first evidence of tissue-specific terminal differentiation of peritoneal macrophages, and this terminal differentiation can be characterized by the expression of STK receptor tyrosine kinase.

Foxp3-positive macrophages display immunosuppressive properties and promote tumor growth

PubMed Central

Zorro Manrique, Soraya; Duque Correa, Maria Adelaida; Hoelzinger, Dominique B.; Dominguez, Ana Lucia; Mirza, Noweeda; Lin, Hsi-Hsien; Stein-Streilein, Joan; Gordon, Siamon

2011-01-01

Regulatory T cells (T reg cells) are characterized by the expression of the forkhead lineage-specific transcription factor Foxp3, and their main function is to suppress T cells. While evaluating T reg cells, we identified a population of Foxp3-positive cells that were CD11b+F4/80+CD68+, indicating macrophage origin. These cells were observed in spleen, lymph nodes, bone marrow, thymus, liver, and other tissues of naive animals. To characterize this subpopulation of macrophages, we devised a strategy to purify CD11b+F4/80+Foxp3+ macrophages using Foxp3-GFP mice. Analysis of CD11b+F4/80+Foxp3+ macrophage function indicated that these cells inhibited the proliferation of T cells, whereas Foxp3− macrophages did not. Suppression of T cell proliferation was mediated through soluble factors. Foxp3− macrophages acquired Foxp3 expression after activation, which conferred inhibitory properties that were indistinguishable from natural Foxp3+ macrophages. The cytokine and transcriptional profiles of Foxp3+ macrophages were distinct from those of Foxp3− macrophages, indicating that these cells have different biological functions. Functional in vivo analyses indicated that CD11b+F4/80+Foxp3+ macrophages are important in tumor promotion and the induction of T reg cell conversion. For the first time, these studies demonstrate the existence of a distinct subpopulation of naturally occurring macrophage regulatory cells in which expression of Foxp3 correlates with suppressive function. PMID:21670203

Tumor development in murine ulcerative colitis depends on MyD88 signaling of colonic F4/80+CD11bhighGr1low macrophages

PubMed Central

Schiechl, Gabriela; Bauer, Bernhard; Fuss, Ivan; Lang, Sven A.; Moser, Christian; Ruemmele, Petra; Rose-John, Stefan; Neurath, Markus F.; Geissler, Edward K.; Schlitt, Hans-Jürgen; Strober, Warren; Fichtner-Feigl, Stefan

2011-01-01

Patients with prolonged ulcerative colitis (UC) frequently develop colorectal adenocarcinoma for reasons that are not fully clear. To analyze inflammation-associated colonic tumorigenesis, we developed a chronic form of oxazolone-induced colitis in mice that, similar to UC, was distinguished by the presence of IL-13–producing NKT cells. In this model, the induction of tumors using azoxymethane was accompanied by the coappearance of F4/80+CD11bhighGr1low M2 macrophages, cells that undergo polarization by IL-13 and are absent in tumors that lack high level IL-13 production. Importantly, this subset of macrophages was a source of tumor-promoting factors, including IL-6. Similar to dextran sodium sulfate–induced colitis, F4/80+CD11bhighGr1intermediate macrophages were present in the mouse model of chronic oxazolone-induced colitis and may influence tumor development through production of TGF-β1, a cytokine that inhibits tumor immunosurveillance. Finally, while robust chronic oxazolone-induced colitis developed in myeloid differentiation primary response gene 88–deficient (Myd88–/–) mice, these mice did not support tumor development. The inhibition of tumor development in Myd88–/– mice correlated with cessation of IL-6 and TGF-β1 production by M2 and F4/80+CD11bhighGr1intermediate macrophages, respectively, and was reversed by exogenous IL-6. These data show that an UC-like inflammation may facilitate tumor development by providing a milieu favoring development of MyD88-dependent tumor-supporting macrophages. PMID:21519141

Cysteamine re-establishes the clearance of Pseudomonas aeruginosa by macrophages bearing the cystic fibrosis-relevant F508del-CFTR mutation.

PubMed

Ferrari, Eleonora; Monzani, Romina; Villella, Valeria R; Esposito, Speranza; Saluzzo, Francesca; Rossin, Federica; D'Eletto, Manuela; Tosco, Antonella; De Gregorio, Fabiola; Izzo, Valentina; Maiuri, Maria C; Kroemer, Guido; Raia, Valeria; Maiuri, Luigi

2017-01-12

Cystic fibrosis (CF), the most common lethal monogenic disease in Caucasians, is characterized by recurrent bacterial infections and colonization, mainly by Pseudomonas aeruginosa, resulting in unresolved airway inflammation. CF is caused by mutations in the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein, which functions as a chloride channel in epithelial cells, macrophages, and other cell types. Impaired bacterial handling by macrophages is a feature of CF airways, although it is still debated how defective CFTR impairs bacterial killing. Recent evidence indicates that a defective autophagy in CF macrophages leads to alterations of bacterial clearance upon infection. Here we use bone marrow-derived macrophages from transgenic mice to provide the genetic proof that defective CFTR compromises both uptake and clearance of internalized Pseudomonas aeruginosa. We demonstrate that the proteostasis regulator cysteamine, which rescues the function of the most common F508del-CFTR mutant and hence reduces lung inflammation in CF patients, can also repair the defects of CF macrophages, thus restoring both bacterial internalization and clearance through a process that involves upregulation of the pro-autophagic protein Beclin 1 and re-establishment of the autophagic pathway. Altogether these results indicate that cysteamine restores the function of several distinct cell types, including that of macrophages, which might contribute to its beneficial effects on CF.

Cysteamine re-establishes the clearance of Pseudomonas aeruginosa by macrophages bearing the cystic fibrosis-relevant F508del-CFTR mutation

PubMed Central

Ferrari, Eleonora; Monzani, Romina; Villella, Valeria R; Esposito, Speranza; Saluzzo, Francesca; Rossin, Federica; D'Eletto, Manuela; Tosco, Antonella; De Gregorio, Fabiola; Izzo, Valentina; Maiuri, Maria C; Kroemer, Guido; Raia, Valeria; Maiuri, Luigi

2017-01-01

Cystic fibrosis (CF), the most common lethal monogenic disease in Caucasians, is characterized by recurrent bacterial infections and colonization, mainly by Pseudomonas aeruginosa, resulting in unresolved airway inflammation. CF is caused by mutations in the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein, which functions as a chloride channel in epithelial cells, macrophages, and other cell types. Impaired bacterial handling by macrophages is a feature of CF airways, although it is still debated how defective CFTR impairs bacterial killing. Recent evidence indicates that a defective autophagy in CF macrophages leads to alterations of bacterial clearance upon infection. Here we use bone marrow-derived macrophages from transgenic mice to provide the genetic proof that defective CFTR compromises both uptake and clearance of internalized Pseudomonas aeruginosa. We demonstrate that the proteostasis regulator cysteamine, which rescues the function of the most common F508del-CFTR mutant and hence reduces lung inflammation in CF patients, can also repair the defects of CF macrophages, thus restoring both bacterial internalization and clearance through a process that involves upregulation of the pro-autophagic protein Beclin 1 and re-establishment of the autophagic pathway. Altogether these results indicate that cysteamine restores the function of several distinct cell types, including that of macrophages, which might contribute to its beneficial effects on CF. PMID:28079883

Specific Macrophage Subtypes Influence the Progression of Rhabdomyolysis-Induced Kidney Injury

PubMed Central

Belliere, Julie; Casemayou, Audrey; Ducasse, Laure; Zakaroff-Girard, Alexia; Martins, Frédéric; Iacovoni, Jason S.; Guilbeau-Frugier, Céline; Buffin-Meyer, Bénédicte; Pipy, Bernard; Chauveau, Dominique

2015-01-01

Rhabdomyolysis can be life threatening if complicated by AKI. Macrophage infiltration has been observed in rat kidneys after glycerol-induced rhabdomyolysis, but the role of macrophages in rhabdomyolysis-induced AKI remains unknown. Here, in a patient diagnosed with rhabdomyolysis, we detected substantial macrophage infiltration in the kidney. In a mouse model of rhabdomyolysis-induced AKI, diverse renal macrophage phenotypes were observed depending on the stage of the disease. Two days after rhabdomyolysis, F4/80lowCD11bhighLy6bhighCD206low kidney macrophages were dominant, whereas by day 8, F4/80highCD11b+Ly6blowCD206high cells became the most abundant. Single-cell gene expression analyses of FACS-sorted macrophages revealed that these subpopulations were heterogeneous and that individual cells simultaneously expressed both M1 and M2 markers. Liposomal clodronate-mediated macrophage depletion significantly reduced the early infiltration of F4/80lowCD11bhighLy6bhighCD206low macrophages. Furthermore, transcriptionally regulated targets potentially involved in disease progression, including fibronectin, collagen III, and chemoattractants that were identified via single-cell analysis, were verified as macrophage-dependent in situ. In vitro, myoglobin treatment induced proximal tubular cells to secrete chemoattractants and macrophages to express proinflammatory markers. At day 30, liposomal clodronate-mediated macrophage depletion reduced fibrosis and improved both kidney repair and mouse survival. Seven months after rhabdomyolysis, histologic lesions were still present but were substantially reduced with prior depletion of macrophages. These results suggest an important role for macrophages in rhabdomyolysis-induced AKI progression and advocate the utility of long-term follow-up for patients with this disease. PMID:25270069

Specific macrophage subtypes influence the progression of rhabdomyolysis-induced kidney injury.

PubMed

Belliere, Julie; Casemayou, Audrey; Ducasse, Laure; Zakaroff-Girard, Alexia; Martins, Frédéric; Iacovoni, Jason S; Guilbeau-Frugier, Céline; Buffin-Meyer, Bénédicte; Pipy, Bernard; Chauveau, Dominique; Schanstra, Joost P; Bascands, Jean-Loup

2015-06-01

Rhabdomyolysis can be life threatening if complicated by AKI. Macrophage infiltration has been observed in rat kidneys after glycerol-induced rhabdomyolysis, but the role of macrophages in rhabdomyolysis-induced AKI remains unknown. Here, in a patient diagnosed with rhabdomyolysis, we detected substantial macrophage infiltration in the kidney. In a mouse model of rhabdomyolysis-induced AKI, diverse renal macrophage phenotypes were observed depending on the stage of the disease. Two days after rhabdomyolysis, F4/80(low)CD11b(high)Ly6b(high)CD206(low) kidney macrophages were dominant, whereas by day 8, F4/80(high)CD11b(+)Ly6b(low)CD206(high) cells became the most abundant. Single-cell gene expression analyses of FACS-sorted macrophages revealed that these subpopulations were heterogeneous and that individual cells simultaneously expressed both M1 and M2 markers. Liposomal clodronate-mediated macrophage depletion significantly reduced the early infiltration of F4/80(low)CD11b(high)Ly6b(high)CD206(low) macrophages. Furthermore, transcriptionally regulated targets potentially involved in disease progression, including fibronectin, collagen III, and chemoattractants that were identified via single-cell analysis, were verified as macrophage-dependent in situ. In vitro, myoglobin treatment induced proximal tubular cells to secrete chemoattractants and macrophages to express proinflammatory markers. At day 30, liposomal clodronate-mediated macrophage depletion reduced fibrosis and improved both kidney repair and mouse survival. Seven months after rhabdomyolysis, histologic lesions were still present but were substantially reduced with prior depletion of macrophages. These results suggest an important role for macrophages in rhabdomyolysis-induced AKI progression and advocate the utility of long-term follow-up for patients with this disease. Copyright © 2015 by the American Society of Nephrology.

Induction of different activated phenotypes of mouse peritoneal macrophages grown in different tissue culture media.

PubMed

Kawakami, Tomoya; Koike, Atsushi; Amano, Fumio

2017-08-01

The role of activated macrophages in the host defense against pathogens or tumor cells has been investigated extensively. Many researchers have been using various culture media in in vitro experiments using macrophages. We previously reported that J774.1/JA-4 macrophage-like cells showed great differences in their activated macrophage phenotypes, such as production of reactive oxygen, nitric oxide (NO) or cytokines depending on the culture medium used, either F-12 (Ham's F-12 nutrient mixture) or Dulbecco modified Eagle's medium (DMEM). To examine whether a difference in the culture medium would influence the functions of primary macrophages, we used BALB/c mouse peritoneal macrophages in this study. Among the activated macrophage phenotypes, the expression of inducible NO synthase in LPS- and/or IFN-γ-treated peritoneal macrophages showed the most remarkable differences between F-12 and DMEM; i.e., NO production by LPS- and/or IFN-γ-treated cells was far lower in DMEM than in F-12. Similar results were obtained with C57BL mouse peritoneal macrophages. Besides, dilution of F-12 medium with saline resulted in a slight decrease in NO production, whereas that of DMEM with saline resulted in a significant increase, suggesting the possibility that DMEM contained some inhibitory factor(s) for NO production. However, such a difference in NO production was not observed when macrophage-like cell lines were examined. These results suggest that phenotypes of primary macrophages could be changed significantly with respect to host inflammatory responses by the surrounding environment including nutritional factors and that these altered macrophage phenotypes might influence the biological host defense.

Cardiac macrophages promote diastolic dysfunction.

PubMed

Hulsmans, Maarten; Sager, Hendrik B; Roh, Jason D; Valero-Muñoz, María; Houstis, Nicholas E; Iwamoto, Yoshiko; Sun, Yuan; Wilson, Richard M; Wojtkiewicz, Gregory; Tricot, Benoit; Osborne, Michael T; Hung, Judy; Vinegoni, Claudio; Naxerova, Kamila; Sosnovik, David E; Zile, Michael R; Bradshaw, Amy D; Liao, Ronglih; Tawakol, Ahmed; Weissleder, Ralph; Rosenzweig, Anthony; Swirski, Filip K; Sam, Flora; Nahrendorf, Matthias

2018-02-05

Macrophages populate the healthy myocardium and, depending on their phenotype, may contribute to tissue homeostasis or disease. Their origin and role in diastolic dysfunction, a hallmark of cardiac aging and heart failure with preserved ejection fraction, remain unclear. Here we show that cardiac macrophages expand in humans and mice with diastolic dysfunction, which in mice was induced by either hypertension or advanced age. A higher murine myocardial macrophage density results from monocyte recruitment and increased hematopoiesis in bone marrow and spleen. In humans, we observed a parallel constellation of hematopoietic activation: circulating myeloid cells are more frequent, and splenic 18 F-FDG PET/CT imaging signal correlates with echocardiographic indices of diastolic dysfunction. While diastolic dysfunction develops, cardiac macrophages produce IL-10, activate fibroblasts, and stimulate collagen deposition, leading to impaired myocardial relaxation and increased myocardial stiffness. Deletion of IL-10 in macrophages improves diastolic function. These data imply expansion and phenotypic changes of cardiac macrophages as therapeutic targets for cardiac fibrosis leading to diastolic dysfunction. © 2018 Hulsmans et al.

Macrophage Pro-Inflammatory Response to Francisella novicida Infection Is Regulated by SHIP

PubMed Central

Parsa, Kishore V. L; Ganesan, Latha P; Rajaram, Murugesan V. S; Gavrilin, Mikhail A; Balagopal, Ashwin; Mohapatra, Nrusingh P; Wewers, Mark D; Schlesinger, Larry S; Gunn, John S; Tridandapani, Susheela

2006-01-01

Francisella tularensis, a Gram-negative facultative intracellular pathogen infecting principally macrophages and monocytes, is the etiological agent of tularemia. Macrophage responses to F. tularensis infection include the production of pro-inflammatory cytokines such as interleukin (IL)-12, which is critical for immunity against infection. Molecular mechanisms regulating production of these inflammatory mediators are poorly understood. Herein we report that the SH2 domain-containing inositol phosphatase (SHIP) is phosphorylated upon infection of primary murine macrophages with the genetically related F. novicida, and negatively regulates F. novicida–induced cytokine production. Analyses of the molecular details revealed that in addition to activating the MAP kinases, F. novicida infection also activated the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in these cells. Interestingly, SHIP-deficient macrophages displayed enhanced Akt activation upon F. novicida infection, suggesting elevated PI3K-dependent activation pathways in absence of SHIP. Inhibition of PI3K/Akt resulted in suppression of F. novicida–induced cytokine production through the inhibition of NFκB. Consistently, macrophages lacking SHIP displayed enhanced NFκB-driven gene transcription, whereas overexpression of SHIP led to decreased NFκB activation. Thus, we propose that SHIP negatively regulates F. novicida–induced inflammatory cytokine response by antagonizing the PI3K/Akt pathway and suppressing NFκB-mediated gene transcription. A detailed analysis of phosphoinositide signaling may provide valuable clues for better understanding the pathogenesis of tularemia. PMID:16848641

Assaying macrophage activity in a murine model of inflammatory bowel disease using fluorine-19 MRI

PubMed Central

Kadayakkara, Deepak K; Ranganathan, Sarangarajan; Young, Won-Bin; Ahrens, Eric T

2012-01-01

Macrophages have an important role in the pathogenesis of most chronic inflammatory diseases. A means of non-invasively quantifying macrophage migration would contribute significantly towards our understanding of chronic inflammatory processes and aid the evaluation of novel therapeutic strategies. We describe the use of a perfluorocarbon tracer reagent and in vivo 19F magnetic resonance imaging (MRI) to quantify macrophage burden longitudinally. We apply these methods to evaluate the severity and three-dimensional distribution of macrophages in a murine model of inflammatory bowel disease (IBD). MRI results were validated by histological analysis, immunofluorescence and quantitative real-time polymerase chain reaction. Selective depletion of macrophages in vivo was also performed, further validating that macrophage accumulation of perfluorocarbon tracers was the basis of 19F MRI signals observed in the bowel. We tested the effects of two common clinical drugs, dexamethasone and cyclosporine A, on IBD progression. Whereas cyclosporine A provided mild therapeutic effect, unexpectedly dexamethasone enhanced colon inflammation, especially in the descending colon. Overall, 19F MRI can be used to evaluate early-stage inflammation in IBD and is suitable for evaluating putative therapeutics. Due to its high macrophage specificity and quantitative ability, we envisage 19F MRI having an important role in evaluating a wide range of chronic inflammatory conditions mediated by macrophages. PMID:22330343

Adipocyte-Macrophage Cross-Talk in Obesity.

PubMed

Engin, Ayse Basak

2017-01-01

Obesity is characterized by the chronic low-grade activation of the innate immune system. In this respect, macrophage-elicited metabolic inflammation and adipocyte-macrophage interaction has a primary importance in obesity. Large amounts of macrophages are accumulated by different mechanisms in obese adipose tissue. Hypertrophic adipocyte-derived chemotactic monocyte chemoattractant protein-1 (MCP-1)/C-C chemokine receptor 2 (CCR2) pathway also promotes more macrophage accumulation into the obese adipose tissue. However, increased local extracellular lipid concentrations is a final mechanism for adipose tissue macrophage accumulation. A paracrine loop involving free fatty acids and tumor necrosis factor-alpha (TNF-alpha) between adipocytes and macrophages establishes a vicious cycle that aggravates inflammatory changes in the adipose tissue. Adipocyte-specific caspase-1 and production of interleukin-1beta (IL-1beta) by macrophages; both adipocyte and macrophage induction by toll like receptor-4 (TLR4) through nuclear factor-kappaB (NF-kappaB) activation; free fatty acid-induced and TLR-mediated activation of c-Jun N-terminal kinase (JNK)-related pro-inflammatory pathways in CD11c+ immune cells; are effective in macrophage accumulation and in the development of adipose tissue inflammation. Old adipocytes are removed by macrophages through trogocytosis or sending an "eat me" signal. The obesity-induced changes in adipose tissue macrophage numbers are mainly due to increases in the triple-positive CD11b+ F4/80+ CD11c+ adipose tissue macrophage subpopulation. The ratio of M1-to-M2 macrophages is increased in obesity. Furthermore, hypoxia along with higher concentrations of free fatty acids exacerbates macrophage-mediated inflammation in obesity. The metabolic status of adipocytes is a major determinant of macrophage inflammatory output. Macrophage/adipocyte fatty-acid-binding proteins act at the interface of metabolic and inflammatory pathways. Both macrophages and

Monoclonal antibody binding to the macrophage-specific receptor sialoadhesin alters the phagocytic properties of human and mouse macrophages.

PubMed

De Schryver, Marjorie; Cappoen, Davie; Elewaut, Dirk; Nauwynck, Hans J; Maes, Louis; Caljon, Guy; Cos, Paul; Delputte, Peter L

2017-02-01

Sialoadhesin (Sn) is a surface receptor expressed on macrophages in steady state conditions, but during inflammation, Sn can be upregulated both on macrophages and on circulating monocytes. It was shown for different species that Sn becomes internalized after binding with monoclonal antibodies. These features suggest that Sn is a potential target for immunotherapies. In this study, human and mouse macrophages were treated with anti-Sn monoclonal antibodies or F(ab') 2 fragments and the effect of their binding to Sn on phagocytosis was analyzed. Binding of antibodies to Sn resulted in delayed and reduced phagocytosis of fluorescent beads. No effect was observed on Fc-mediated phagocytosis or phagocytosis of bacteria by human macrophages. In contrast, an enhanced phagocytosis of bacteria by mouse macrophages was detected. These results showed that stimulation of Sn could have different effects on macrophage phagocytosis, depending both on the type of phagocytosis and cellular background. Copyright © 2016 Elsevier Inc. All rights reserved.

Evidence for differential activation of arachidonic acid metabolism in formylpeptide- and macrophage-activation-factor-stimulated guinea-pig macrophages.

PubMed Central

Homma, Y; Hashimoto, T; Nagai, Y; Takenawa, T

1985-01-01

Alterations of phospholipid and arachidonic acid metabolism were studied by treatment of guinea-pig peritoneal-exudate macrophages with chemotactic peptide, formylmethionyl-leucylphenylalanine (fMet-Leu-Phe) and macrophage activation factor (MAF). The chemotactic peptide caused a rapid rearrangement in inositol phospholipids, including a breakdown of polyphosphoinositides within 30s, followed by a resultant formation of phosphatidylinositol (PI), diacylglycerol, phosphatidic acid and non-esterified arachidonic acid within 5 min. In addition to these sequential alterations, arachidonic acid was released mainly from PI. On the other hand, MAF induced a slow liberation of arachidonic acid, mainly from phosphatidylethanolamine (PE) and phosphatidylcholine (PC) by phospholipase A2 after the incubation period of 30 min, but not any rapid changes in phospholipids. Treatment of macrophages for 15 min with fMet-Leu-Phe produced the leukotrienes (LTs) B4, C4 and D4, prostaglandins (PG) E2 and F2 alpha and thromboxane (TX) B2. In contrast, MAF could not stimulate the production of arachidonic acid metabolites during the incubation period of 15 min, but could enhance that of PGE2, PGF2 alpha, TXB2 and hydroxyeicosatetraenoic acids at 6 h. However, the stimulated formation of LTs was not detected at any time. These results indicate that the effects of fMet-Leu-Phe on both phospholipid and arachidonic acid metabolism are very different from those mediated by MAF. PMID:3931627

Serum from aged F344 rats conditions the activation of young macrophages.

PubMed

Gómez, Christian R; Acuña-Castillo, Claudio; Nishimura, Sumiyo; Pérez, Viviana; Escobar, Alejandro; Salazar-Onfray, Flavio; Sabaj, Valeria; Torres, Claudio; Walter, Robin; Sierra, Felipe

2006-03-01

There is considerable controversy about the molecular mechanisms responsible for the variations in innate immunity associated with age. While in vivo, aged animals and humans react to an inflammatory signal with an excessive production of pro-inflammatory cytokines, studies in vitro generally show that this response is attenuated in macrophages from old individuals. In an effort to examine possible extrinsic factors that might affect the response of macrophages to lipopolysaccharide (LPS), we have challenged peritoneal macrophages obtained from young rats with sera obtained from rats of different ages. Our results indicate that the serum from aged rats significantly impairs the capacity of young macrophages to induce tumor necrosis factor-alpha (TNF-alpha) production, while at the same time it increases the basal levels of interleukin-6 (IL-6). The effect of serum from aged donors on TNF-alpha secretion requires pre-incubation and is sensitive to heat inactivation. In contrast, the stimulating effect on IL-6 is resistant to heat, and thus should not be due to a protein factor. Therefore, our results indicate that the age-related changes in macrophage activity are not only the consequence of intrinsic changes, but there also appears to be a modulatory effect imparted by the external milieu.

Augmented macrophage differentiation and polarization of tumor-associated macrophages towards M1 subtype in listeria-administered tumor-bearing host.

PubMed

Rai, Rakesh K; Vishvakarma, Naveen K; Mohapatra, Tribhuban M; Singh, Sukh Mahendra

2012-09-01

This study investigates the effect of Listeria administration on differentiation of macrophages from precursor bone marrow cells and functional status of tumor-associated macrophages (TAM). Listeria administration not only resulted in an augmented infiltration of tumor by F4/80 macrophages but also repolarized the functional status of TAM displaying features of some M1 macrophage subtype with upregulated phagocytosis and tumoricidal activity accompanied by altered expression of monocarboxylate transporter-1, toll-like receptor-2, surface markers: CD11c, interleukin-2 receptor, CD62L, and secreted molecules: nitric oxide, interleukin (IL)-1, IL-6, tumor necrosis factor-α, and vascular endothelial growth factor. Declined tumor cell survival and modulated repertoire of cytokines: interferon-γ, IL-6, IL-10, and transforming growth factor-β in tumor microenvironment indicated their role in polarization of TAM towards proinflammatory state. Bone marrow cell of Listeria-administered tumor-bearing mice showed augmented survival, declined expression of p53 upregulated modulator of apoptosis with an upregulated differentiation into activation responsive bone marrow-derived macrophages along with altered expression of macrophage-colony stimulating factor, macrophage-colony stimulating factor receptor, and granulocyte macrophage-colony stimulating factor receptor. These findings indicate that Listeria infection is associated with an augmented differentiation of macrophages accompanied by tumoricidal activation of TAM.

Identification of Francisella novicida mutants that fail to induce prostaglandin E2 synthesis by infected macrophages

PubMed Central

Woolard, Matthew D.; Barrigan, Lydia M.; Fuller, James R.; Buntzman, Adam S.; Bryan, Joshua; Manoil, Colin; Kawula, Thomas H.; Frelinger, Jeffrey A.

2013-01-01

Francisella tularensis is the causative agent of tularemia. We have previously shown that infection with F. tularensis Live Vaccine Strain (LVS) induces macrophages to synthesize prostaglandin E2 (PGE2). Synthesis of PGE2 by F. tularensis infected macrophages results in decreased T cell proliferation in vitro and increased bacterial survival in vivo. Although we understand some of the biological consequences of F. tularensis induced PGE2 synthesis by macrophages, we do not understand the cellular pathways (neither host nor bacterial) that result in up-regulation of the PGE2 biosynthetic pathway in F. tularensis infected macrophages. We took a genetic approach to begin to understand the molecular mechanisms of bacterial induction of PGE2 synthesis from infected macrophages. To identify F. tularensis genes necessary for the induction of PGE2 in primary macrophages, we infected cells with individual mutants from the closely related strain F. tularensis subspecies novicida U112 (U112) two allele mutant library. Twenty genes were identified that when disrupted resulted in U112 mutant strains unable to induce the synthesis of PGE2 by infected macrophages. Fourteen of the genes identified are located within the Francisella pathogenicity island (FPI). Genes in the FPI are required for F. tularensis to escape from the phagosome and replicate in the cytosol, which might account for the failure of U112 with transposon insertions within the FPI to induce PGE2. This implies that U112 mutant strains that do not grow intracellularly would also not induce PGE2. We found that U112 clpB::Tn grows within macrophages yet fails to induce PGE2, while U112 pdpA::Tn does not grow yet does induce PGE2. We also found that U112 iglC::Tn neither grows nor induces PGE2. These findings indicate that there is dissociation between intracellular growth and the ability of F. tularensis to induce PGE2 synthesis. These mutants provide a critical entrée into the pathways used in the host for PGE2

Fenspiride and membrane transduction signals in rat alveolar macrophages.

PubMed

Féray, J C; Mohammadi, K; Taouil, K; Brunet, J; Garay, R P; Hannaert, P

1997-07-15

Fenspiride inhibits the calcium signal evoked by the inflammatory peptide formyl-Met-Leu-Phe (fMLP) in peritoneal macrophages, but at concentrations (approximately 1 mM) far above the therapeutic range (approximately 1 microM). Here, in rat alveolar macrophages, high fenspiride concentrations (1 mM) were required to inhibit the calcium signals evoked by the calcium agonist Bay K8644 or by ionomycin. Moreover, fenspiride (1 mM) was a poor inhibitor of the cell membrane depolarization induced by gramicidine D. By contrast, fenspiride blocked Na+-H+ antiport activation by (i) fMLP with an IC50 = 3.1 +/- 1.9 nM and (ii) PMA (phorbol 12-myristate 13-acetate) with an IC50 = 9.2 +/- 3.1 nM. Finally, protein kinase C (PKC) activity of macrophage homogenate was not significantly modified by 10 or 100 microM fenspiride (at 100 microM: 2.57 +/- 1.60 vs. 2.80 +/- 1.71 pmol/10(6) cells/min). In conclusion, fenspiride inhibits fMLP- and PMA-induced pH signals in rat alveolar macrophages, probably by acting distally on the PKC transduction signal. This pH antagonistic action may be relevant for the antiinflammatory mechanism of fenspiride and requires further investigation.

Absence of erythroblast macrophage protein (Emp) leads to failure of erythroblast nuclear extrusion.

PubMed

Soni, Shivani; Bala, Shashi; Gwynn, Babette; Sahr, Kenneth E; Peters, Luanne L; Hanspal, Manjit

2006-07-21

In mammals, the functional unit for definitive erythropoiesis is the erythroblastic island, a multicellular structure composed of a central macrophage surrounded by developing erythroblasts. Erythroblast-macrophage interactions play a central role in the terminal maturation of erythroblasts, including enucleation. One possible mediator of this cell-cell interaction is the protein Emp (erythroblast macrophage protein). We used targeted gene inactivation to define the function of Emp during hematopoiesis. Emp null embryos die perinatally and show profound alterations in the hematopoietic system. A dramatic increase in the number of nucleated, immature erythrocytes is seen in the peripheral blood of Emp null fetuses. In the fetal liver virtually no erythroblastic islands are observed, and the number of F4/80-positive macrophages is substantially reduced. Those present lack cytoplasmic projections and are unable to interact with erythroblasts. Interestingly, wild type macrophages can bind Emp-deficient erythroblasts, but these erythroblasts do not extrude their nuclei, suggesting that Emp impacts enucleation in a cell autonomous fashion. Previous studies have implicated the actin cytoskeleton and its reorganization in both erythroblast enucleation as well as in macrophage development. We demonstrate that Emp associates with F-actin and that this interaction is important in the normal distribution of F-actin in both erythroblasts and macrophages. Thus, Emp appears to be required for erythroblast enucleation and in the development of the mature macrophages. The availability of an Emp null model provides a unique experimental system to study the enucleation process and to evaluate the function of macrophages in definitive erythropoiesis.

Interactions between Leishmania braziliensis and Macrophages Are Dependent on the Cytoskeleton and Myosin Va

PubMed Central

Azevedo, Elisama; Oliveira, Leandro Teixeira; Castro Lima, Ana Karina; Terra, Rodrigo; Dutra, Patrícia Maria Lourenço; Salerno, Verônica P.

2012-01-01

Leishmaniasis is a neglected tropical disease with no effective vaccines. Actin, microtubules and the actin-based molecular motor myosin Va were investigated for their involvement in Leishmania braziliensis macrophage interactions. Results showed a decrease in the association index when macrophages were without F-actin or microtubules regardless of the activation state of the macrophage. In the absence of F-actin, the production of NO in non-activated cells increased, while in activated cells, the production of NO was reduced independent of parasites. The opposite effect of an increased NO production was observed in the absence of microtubules. In activated cells, the loss of cytoskeletal components inhibited the release of IL-10 during parasite interactions. The production of IL-10 also decreased in the absence of actin or microtubules in non-activated macrophages. Only the disruption of actin altered the production of TNF-α in activated macrophages. The expression of myosin Va tail resulted in an acute decrease in the association index between transfected macrophages and L. braziliensis promastigotes. These data reveal the importance of F-actin, microtubules, and myosin-Va suggesting that modulation of the cytoskeleton may be a mechanism used by L. braziliensis to overcome the natural responses of macrophages to establish infections. PMID:22792440

Interactions between Leishmania braziliensis and Macrophages Are Dependent on the Cytoskeleton and Myosin Va.

PubMed

Azevedo, Elisama; Oliveira, Leandro Teixeira; Castro Lima, Ana Karina; Terra, Rodrigo; Dutra, Patrícia Maria Lourenço; Salerno, Verônica P

2012-01-01

Leishmaniasis is a neglected tropical disease with no effective vaccines. Actin, microtubules and the actin-based molecular motor myosin Va were investigated for their involvement in Leishmania braziliensis macrophage interactions. Results showed a decrease in the association index when macrophages were without F-actin or microtubules regardless of the activation state of the macrophage. In the absence of F-actin, the production of NO in non-activated cells increased, while in activated cells, the production of NO was reduced independent of parasites. The opposite effect of an increased NO production was observed in the absence of microtubules. In activated cells, the loss of cytoskeletal components inhibited the release of IL-10 during parasite interactions. The production of IL-10 also decreased in the absence of actin or microtubules in non-activated macrophages. Only the disruption of actin altered the production of TNF-α in activated macrophages. The expression of myosin Va tail resulted in an acute decrease in the association index between transfected macrophages and L. braziliensis promastigotes. These data reveal the importance of F-actin, microtubules, and myosin-Va suggesting that modulation of the cytoskeleton may be a mechanism used by L. braziliensis to overcome the natural responses of macrophages to establish infections.

A cell-ELISA for the quantification of adherent murine macrophages and the surface expression of antigens.

PubMed

Nibbering, P H; Van de Gevel, J S; Van Furth, R

1990-07-20

The present study was performed in order to establish whether a cell-ELISA could be used to determine the expression of antigens by adherent murine peritoneal macrophages and also quantify the numbers of such macrophages. Accurate determination of the number of adherent macrophages proved to be possible with a cell-ELISA designed to assess complement receptor type III (CRIII) expression. Expression of CRIII was considerably more sensitive than determination of the cell-protein or DNA content as a measure of the number of adherent macrophages. For the calculation of the expression of CRIII, Ia antigen, and antigen F4/80 by resident and activated macrophages, use was made of the linear part of the curve obtained when the numbers of macrophages were plotted against the absorbance values for each of the antigens. The values for CRIII expression did not differ significantly between resident macrophages, macrophages activated with recombinant interferon-gamma (rIFN-gamma) and macrophages activated with BCG/PPD. IFN-gamma-activated and BCG/PPD-activated macrophages expressed Ia antigen significantly more intensely than did resident peritoneal macrophages. In contrast the activated macrophages expressed F4/80 significantly less intensely than resident peritoneal macrophages.

miRNA-34b is directly involved in the aging of macrophages.

PubMed

Liang, Wei; Gao, Sheng; Liang, Liu; Huang, Xianing; Hu, Nan; Lu, Xiaoling; Zhao, Yongxiang

2017-08-01

MicroRNAs (miRNAs) are a class of short noncoding RNA that play important regulatory roles in living organisms. These RNA molecules are implicated in the development and progression of malignant diseases such as cancer and are closely associated with cell aging. Findings demonstrating that microRNA is associated with aging in macrophages have nevertheless rarely been reported. This study's objective was to investigate if miRNA-34 is linked to aging process of macrophages. We built a cell aging model in mouse RAW264.7 macrophages using D-galactose and determined the expression levels of miRNA-34a, miRNA-34b, and miRNA-34c in aging and normal macrophages by fluorescence quantitative polymerase chain reaction (q-PCR). We predicted a target gene of miRNA-34 using biological information techniques and constructed the recombinant plasmid pGL3-E2f3 for the putative target gene E2f3. The expression level of miRNA-34b was 5.23 times higher in aging macrophages than in normal macrophages. The luciferase activity decreased by nearly 50 % in cells transfected with miRNA-34b mimics, while no significant decrease in luciferase activity was noted in cells transfected with the miRNA-34b inhibitor or unrelated sequences. Our findings provide the groundwork for further research into the molecular mechanisms whereby miRNA-34b regulates the aging of macrophages. miRNA-34b is associated with the aging of RAW264.7 macrophages, and E2f3 is a target gene of miRNA-34b.

Inactivation of the F4/80 glycoprotein in the mouse germ line.

PubMed

Schaller, Evelyne; Macfarlane, Alison J; Rupec, Rudolf A; Gordon, Siamon; McKnight, Andrew J; Pfeffer, Klaus

2002-11-01

Macrophages play a crucial role in the defense against pathogens. Distinct macrophage populations can be defined by the expression of restricted cell surface proteins. Resident tissue macrophages, encompassing Kupffer cells of the liver and red pulp macrophages of the spleen, characteristically express the F4/80 molecule, a cell surface glycoprotein related to the seven transmembrane-spanning family of hormone receptors. In this study, gene targeting was used to simultaneously inactivate the F4/80 molecule in the germ line of the mouse and to produce a mouse line that expresses the Cre recombinase under the direct control of the F4/80 promoter (F4/80-Cre knock-in). F4/80-deficient mice are healthy and fertile. Macrophage populations in tissues can develop in the absence of F4/80 expression. Functional analysis revealed that the generation of T-cell-independent B-cell responses and macrophage antimicrobial defense after infection with Listeria monocytogenes are not impaired in the absence of F4/80. Interestingly, tissues of F4/80-deficient mice could not be labeled with anti-BM8, another macrophage subset-specific marker with hitherto undefined molecular antigenic structure. Recombinant expression of a F4/80 cDNA in heterologous cells confirmed this observation, indicating that the targets recognized by the F4/80 and BM8 monoclonal antibodies are identical.

Peroxisome proliferator-activated receptor-gamma agonist rosiglitazone attenuates postincisional pain by regulating macrophage polarization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hasegawa-Moriyama, Maiko, E-mail: hase-mai@m3.kufm.kagoshima-u.ac.jp; Ohnou, Tetsuya; Godai, Kohei

Highlights: Black-Right-Pointing-Pointer Rosiglitazone attenuated postincisional pain. Black-Right-Pointing-Pointer Rosiglitazone alters macrophage polarization to F4/80{sup +}CD206{sup +} M2 macrophages at the incisional sites. Black-Right-Pointing-Pointer Transplantation of rosiglitazone-treated macrophages produced analgesic effects. -- Abstract: Acute inflammation triggered by macrophage infiltration to injured tissue promotes wound repair and may induce pain hypersensitivity. Peroxisome proliferator-activated receptor {gamma} (PPAR){gamma} signaling is known to regulate heterogeneity of macrophages, which are often referred to as classically activated (M1) and alternatively activated (M2) macrophages. M1 macrophages have considerable antimicrobial activity and produce a wide variety of proinflammatory cytokines. In contrast, M2 macrophages are involved in anti-inflammatory and homeostatic functionsmore » linked to wound healing and tissue repair. Although it has been suggested that PPAR{gamma} agonists attenuate pain hypersensitivity, the molecular mechanism of macrophage-mediated effects of PPAR{gamma} signaling on pain development has not been explored. In this study, we investigated the link between the phenotype switching of macrophage polarization induced by PPAR{gamma} signaling and the development of acute pain hypersensitivity. Local administration of rosiglitazone significantly ameliorated hypersensitivity to heat and mechanical stimuli, and paw swelling. Consistent with the down-regulation of nuclear factor {kappa}B (NF{kappa}B) phosphorylation by rosiglitazone at the incisional sites, the number of F4/80{sup +}iNOS{sup +} M1 macrophages was decreased whereas numbers of F4/80{sup +}CD206{sup +} M2 macrophages were increased in rosiglitazone-treated incisional sites 24 h after the procedure. In addition, gene induction of anti-inflammatory M2-macrophage-associated markers such as arginase1, FIZZ1 and interleukin (IL)-10 were significantly increased

Primary cilia disruption differentially affects the infiltrating and resident macrophage compartment in the liver.

PubMed

Zimmerman, Kurt A; Song, Cheng Jack; Gonzalez-Mize, Nancy; Li, Zhang; Yoder, Bradley K

2018-06-01

Hepatorenal fibrocystic disease (HRFCD) is characterized by cysts in the kidney and liver with associated fibrosis and is the result of defects in proteins required for cilia function or assembly. Previous reports indicate that macrophages, mainly M2-like macrophages, contribute to HRFCD, although the origin of these cells (yolk sac-derived resident macrophages vs. bone marrow-derived infiltrating macrophages) and their contribution to the observed phenotypes are unknown. We utilize a congenital model of cilia dysfunction (IFT88 Orpk ) to study the importance of macrophages in HRFCD. Our data show a rapid expansion of the bile duct region and development of fibrosis between 2 and 4 wk of age. Immunofluorescence microscopy analysis reveals an accumulation of F4/80 + macrophages in regions exhibiting biliary hyperplasia in IFT88 Orpk mice. Flow cytometry data show that cilia dysfunction leads to an accumulation of infiltrating macrophages (CD11b hi , F4/80 lo ) and a reduction of resident macrophage (CD11b lo , F4/80 hi ) number. A majority of the infiltrating macrophages are Ly6c hi profibrogenic macrophages. Along with the accumulation of immune cells, expression of proinflammatory and profibrotic transcripts, including TGF-β, TNF-α, IL-1β, and chemokine (C-C) motif ligand 2, is increased. Quantitative RT-PCR analysis of flow-sorted cells shows enhanced expression of CCL2 in cholangiocytes and enhanced expression of VEGF-A and IL-6 in Ly6c hi macrophages. Genetic inhibition of Ly6c hi macrophage accumulation in IFT88 Orpk FVB CCR2 -/- mice reduced biliary fibrosis but did not affect epithelial expansion. Collectively, these studies suggest that biliary epithelium with defects in primary cilia preferentially recruits Ly6c hi infiltrating macrophages, which promote fibrotic progression in HRFCD pathogenesis. NEW & NOTEWORTHY These studies are the first to address the contribution of the infiltrating and resident macrophage niche during progression of hepatorenal

Alginic acid cell entrapment: a novel method for measuring in vivo macrophage cholesterol homeostasis

PubMed Central

Sontag, Timothy J.; Chellan, Bijoy; Bhanvadia, Clarissa V.; Getz, Godfrey S.; Reardon, Catherine A.

2015-01-01

Macrophage conversion to atherosclerotic foam cells is partly due to the balance of uptake and efflux of cholesterol. Cholesterol efflux from cells by HDL and its apoproteins for subsequent hepatic elimination is known as reverse cholesterol transport. Numerous methods have been developed to measure in vivo macrophage cholesterol efflux. Most methods do not allow for macrophage recovery for analysis of changes in cellular cholesterol status. We describe a novel method for measuring cellular cholesterol balance using the in vivo entrapment of macrophages in alginate, which retains incorporated cells while being permeable to lipoproteins. Recipient mice were injected subcutaneously with CaCl2 forming a bubble into which a macrophage/alginate suspension was injected, entrapping the macrophages. Cells were recovered after 24 h. Cellular free and esterified cholesterol mass were determined enzymatically and normalized to cellular protein. Both normal and cholesterol loaded macrophages undergo measureable changes in cell cholesterol when injected into WT and apoA-I-, LDL-receptor-, or apoE-deficient mice. Cellular cholesterol balance is dependent on initial cellular cholesterol status, macrophage cholesterol transporter expression, and apolipoprotein deficiency. Alginate entrapment allows for the in vivo measurement of macrophage cholesterol homeostasis and is a novel platform for investigating the role of genetics and therapeutic interventions in atherogenesis. PMID:25465389

Infection with Salmonella enterica Serovar Typhimurium Leads to Increased Proportions of F4/80+ Red Pulp Macrophages and Decreased Proportions of B and T Lymphocytes in the Spleen.

PubMed

Rosche, Kristin L; Aljasham, Alanoud T; Kipfer, James N; Piatkowski, Bryan T; Konjufca, Vjollca

2015-01-01

Infection of mice with Salmonella enterica serovar Typhimurium (Salmonella) causes systemic inflammatory disease and enlargement of the spleen (splenomegaly). Splenomegaly has been attributed to a general increase in the numbers of phagocytes, lymphocytes, as well as to the expansion of immature CD71+Ter119+ reticulocytes. The spleen is important for recycling senescent red blood cells (RBCs) and for the capture and eradication of blood-borne pathogens. Conservation of splenic tissue architecture, comprised of the white pulp (WP), marginal zone (MZ), and red pulp (RP) is essential for initiation of adaptive immune responses to captured pathogens. Using flow cytometry and four color immunofluorescence microscopy (IFM), we show that Salmonella-induced splenomegaly is characterized by drastic alterations of the splenic tissue architecture and cell population proportions, as well as in situ cell distributions. A major cause of splenomegaly appears to be the significant increase in immature RBC precursors and F4/80+ macrophages that are important for recycling of heme-associated iron. In contrast, the proportions of B220+, CD4+ and CD8+ lymphocytes, as well as MZ MOMA+ macrophages decrease significantly as infection progresses. Spleen tissue sections show visible tears and significantly altered tissue architecture with F4/80+ macrophages and RBCs expanding beyond the RP and taking over most of the spleen tissue. Additionally, F4/80+ macrophages actively phagocytose not only RBCs, but also lymphocytes, indicating that they may contribute to declining lymphocyte proportions during Salmonella infection. Understanding how these alterations of spleen microarchitecture impact the generation of adaptive immune responses to Salmonella has implications for understanding Salmonella pathogenesis and for the design of more effective Salmonella-based vaccines.

Ovarian teratoma displaying a wide variety of tissue components in a broiler chicken (Gallus Domesticus): morphological heterogeneity of pluripotential germ cell during tumorigenesis.

PubMed

Ohfuji, S

2016-01-01

Spontaneous ovarian teratoma was found in a seven-week-old female Chunky broiler chicken that was slaughtered for food. On post-mortem inspection, a spherical tumor mass attaching to a juvenile ovary was found in the abdominal cavity. Histopathologically, the tumor was comprised of immature mesenchymal stroma and a variety of mature tissue elements of mesodermal and ectodermal origin. In addition, there were multiple indistinguishable tissue elements, which showed no malignant cytological features but were unidentifiable as to corresponding embryological layer of origin. These heterogeneous teratoma tissues consisted of a variety of glandular, cystic, duct-like, and tubular structures, some of which exhibited a lining by a mixture of both keratinizing/non-keratinizing stratified squamous epithelial cells and cuboidal/columnar epithelial cells. The ovarian tetatoma was considered a benign and congenital one. The highly diverse differentiation of the teratoma might have manifested a morphological aspect of intrinsic character of the pluripotential germ cells during tumorigenesis.

Effect of macrophages on in vitro corrosion behavior of magnesium alloy.

PubMed

Zhang, Jian; Hiromoto, Sachiko; Yamazaki, Tomohiko; Niu, Jialin; Huang, Hua; Jia, Gaozhi; Li, Haiyan; Ding, Wenjiang; Yuan, Guangyin

2016-10-01

The influence of cells on the corrosion behavior of biomedical magnesium alloy is an important but less studied topic, which is helpful for understanding the inconsistent corrosion rates between in vitro and in vivo experiments. In this work, macrophages were directly cultured on Mg-2.1Nd-0.2Zn-0.5Zr (wt %, abbreviated as JDBM) alloy surface for 72 or 168 hours. Macrophages retained good viability and the generation of reactive oxygen species (ROS) was greatly promoted on the alloy. Weight loss, Mg(2+) concentration, and cross-section observation results demonstrated that macrophages accelerated the in vitro corrosion of JDBM. The coverage of cell body did not affect the local thickness of corrosion product layer. The corrosion product layer had a porous inner Mg(OH)2 layer and a dense outer layer mainly composed of O, P, Mg, and Ca. The uniform acceleration of JDBM corrosion was attributed to the omnidirection diffusion of ROS from macrophages. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2476-2487, 2016. © 2016 Wiley Periodicals, Inc.

Alendronate inhalation ameliorates elastase-induced pulmonary emphysema in mice by induction of apoptosis of alveolar macrophages.

PubMed

Ueno, Manabu; Maeno, Toshitaka; Nishimura, Satoshi; Ogata, Fusa; Masubuchi, Hiroaki; Hara, Kenichiro; Yamaguchi, Kouichi; Aoki, Fumiaki; Suga, Tatsuo; Nagai, Ryozo; Kurabayashi, Masahiko

2015-03-10

Alveolar macrophages play a crucial role in the pathogenesis of emphysema, for which there is currently no effective treatment. Bisphosphonates are widely used to treat osteoclast-mediated bone diseases. Here we show that delivery of the nitrogen-containing bisphosphonate alendronate via aerosol inhalation ameliorates elastase-induced emphysema in mice. Inhaled, but not orally ingested, alendronate inhibits airspace enlargement after elastase instillation, and induces apoptosis of macrophages in bronchoalveolar fluid via caspase-3- and mevalonate-dependent pathways. Cytometric analysis indicates that the F4/80(+)CD11b(high)CD11c(mild) population characterizing inflammatory macrophages, and the F4/80(+)CD11b(mild)CD11c(high) population defining resident alveolar macrophages take up substantial amounts of the bisphosphonate imaging agent OsteoSense680 after aerosol inhalation. We further show that alendronate inhibits macrophage migratory and phagocytotic activities and blunts the inflammatory response of alveolar macrophages by inhibiting nuclear factor-κB signalling. Given that the alendronate inhalation effectively induces apoptosis in both recruited and resident alveolar macrophages, we suggest this strategy may have therapeutic potential for the treatment of emphysema.

Oxidized LDL triggers changes in oxidative stress and inflammatory biomarkers in human macrophages.

PubMed

Lara-Guzmán, Oscar J; Gil-Izquierdo, Ángel; Medina, Sonia; Osorio, Edison; Álvarez-Quintero, Rafael; Zuluaga, Natalia; Oger, Camille; Galano, Jean-Marie; Durand, Thierry; Muñoz-Durango, Katalina

2018-05-01

Oxidized low-density lipoprotein (oxLDL) is a well-recognized proatherogenic particle that functions in atherosclerosis. In this study, we established conditions to generate human oxLDL, characterized according to the grade of lipid and protein oxidation, particle size and oxylipin content. The induction effect of the cellular proatherogenic response was assessed in foam cells by using an oxLDL-macrophage interaction model. Uptake of oxLDL, reactive oxygen species production and expression of oxLDL receptors (CD36, SR-A and LOX-1) were significantly increased in THP-1 macrophages. Analyses of 35 oxylipins revealed that isoprostanes (IsoP) and prostaglandins (PGs) derived from the oxidation of arachidonic, dihomo gamma-linolenic and eicosapentaenoic acids were strongly and significantly induced in macrophages stimulated with oxLDL. Importantly, the main metabolites responsible for the THP1-macrophage response to oxLDL exposure were the oxidative stress markers 5-epi-5-F 2t -IsoP, 15-E 1t -IsoP, 8-F 3t -IsoP and 15-keto-15-F 2t -IsoP as well as inflammatory markers PGDM, 17-trans-PGF 3α , and 11β-PGF 2α , all of which are reported here, for the first time, to function in the interaction of oxLDL with THP-1 macrophages. By contrast, a salvage pathway mediated by anti-inflammatory PGs (PGE 1 and 17-trans-PGF 3α ) was also identified, suggesting a response to oxLDL-induced injury. In conclusion, when THP-1 macrophages were treated with oxLDL, a specific induction of biomarkers related to oxidative stress and inflammation was triggered. This work contributes to our understanding of initial atherogenic events mediated by oxLDL-macrophage interactions and helps to generate new approaches for their modulation. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Indirect macrophage responses to ionizing radiation: implications for genotype-dependent bystander signaling.

PubMed

Coates, Philip J; Rundle, Jana K; Lorimore, Sally A; Wright, Eric G

2008-01-15

In addition to the directly mutagenic effects of energy deposition in DNA, ionizing radiation is associated with a variety of untargeted and delayed effects that result in ongoing bone marrow damage. Delayed effects are genotype dependent with CBA/Ca mice, but not C57BL/6 mice, susceptible to the induction of damage and also radiation-induced acute myeloid leukemia. Because macrophages are a potential source of ongoing damaging signals, we have determined their gene expression profiles and we show that bone marrow-derived macrophages show widely different intrinsic expression patterns. The profiles classify macrophages derived from CBA/Ca mice as M1-like (pro-inflammatory) and those from C57BL/6 mice as M2-like (anti-inflammatory); measurements of NOS2 and arginase activity in normal bone marrow macrophages confirm these findings. After irradiation in vivo, but not in vitro, C57BL/6 macrophages show a reduction in NOS2 and an increase in arginase activities, indicating a further M2 response, whereas CBA/Ca macrophages retain an M1 phenotype. Activation of specific signal transducer and activator of transcription signaling pathways in irradiated hemopoietic tissues supports these observations. The data indicate that macrophage activation is not a direct effect of radiation but a tissue response, secondary to the initial radiation exposure, and have important implications for understanding genotype-dependent responses and the mechanisms of the hemotoxic and leukemogenic consequences of radiation exposure.

Cerebral 18F-FDG PET in macrophagic myofasciitis: An individual SVM-based approach.

PubMed

Blanc-Durand, Paul; Van Der Gucht, Axel; Guedj, Eric; Abulizi, Mukedaisi; Aoun-Sebaiti, Mehdi; Lerman, Lionel; Verger, Antoine; Authier, François-Jérôme; Itti, Emmanuel

2017-01-01

Macrophagic myofasciitis (MMF) is an emerging condition with highly specific myopathological alterations. A peculiar spatial pattern of a cerebral glucose hypometabolism involving occipito-temporal cortex and cerebellum have been reported in patients with MMF; however, the full pattern is not systematically present in routine interpretation of scans, and with varying degrees of severity depending on the cognitive profile of patients. Aim was to generate and evaluate a support vector machine (SVM) procedure to classify patients between healthy or MMF 18F-FDG brain profiles. 18F-FDG PET brain images of 119 patients with MMF and 64 healthy subjects were retrospectively analyzed. The whole-population was divided into two groups; a training set (100 MMF, 44 healthy subjects) and a testing set (19 MMF, 20 healthy subjects). Dimensionality reduction was performed using a t-map from statistical parametric mapping (SPM) and a SVM with a linear kernel was trained on the training set. To evaluate the performance of the SVM classifier, values of sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV) and accuracy (Acc) were calculated. The SPM12 analysis on the training set exhibited the already reported hypometabolism pattern involving occipito-temporal and fronto-parietal cortices, limbic system and cerebellum. The SVM procedure, based on the t-test mask generated from the training set, correctly classified MMF patients of the testing set with following Se, Sp, PPV, NPV and Acc: 89%, 85%, 85%, 89%, and 87%. We developed an original and individual approach including a SVM to classify patients between healthy or MMF metabolic brain profiles using 18F-FDG-PET. Machine learning algorithms are promising for computer-aided diagnosis but will need further validation in prospective cohorts.

Myosin Va Bound to Phagosomes Binds to F-Actin and Delays Microtubule-dependent Motility

PubMed Central

Al-Haddad, Ahmed; Shonn, Marion A.; Redlich, Bärbel; Blocker, Ariel; Burkhardt, Janis K.; Yu, Hanry; Hammer, John A.; Weiss, Dieter G.; Steffen, Walter; Griffiths, Gareth; Kuznetsov, Sergei A.

2001-01-01

We established a light microscopy-based assay that reconstitutes the binding of phagosomes purified from mouse macrophages to preassembled F-actin in vitro. Both endogenous myosin Va from mouse macrophages and exogenous myosin Va from chicken brain stimulated the phagosome–F-actin interaction. Myosin Va association with phagosomes correlated with their ability to bind F-actin in an ATP-regulated manner and antibodies to myosin Va specifically blocked the ATP-sensitive phagosome binding to F-actin. The uptake and retrograde transport of phagosomes from the periphery to the center of cells in bone marrow macrophages was observed in both normal mice and mice homozygous for the dilute-lethal spontaneous mutation (myosin Va null). However, in dilute-lethal macrophages the accumulation of phagosomes in the perinuclear region occurred twofold faster than in normal macrophages. Motion analysis revealed saltatory phagosome movement with temporarily reversed direction in normal macrophages, whereas almost no reversals in direction were observed in dilute-lethal macrophages. These observations demonstrate that myosin Va mediates phagosome binding to F-actin, resulting in a delay in microtubule-dependent retrograde phagosome movement toward the cell center. We propose an “antagonistic/cooperative mechanism” to explain the saltatory phagosome movement toward the cell center in normal macrophages. PMID:11553713

Conditional deletion of caspase-8 in macrophages alters macrophage activation in a RIPK-dependent manner.

PubMed

Cuda, Carla M; Misharin, Alexander V; Khare, Sonal; Saber, Rana; Tsai, FuNien; Archer, Amy M; Homan, Philip J; Haines, G Kenneth; Hutcheson, Jack; Dorfleutner, Andrea; Budinger, G R Scott; Stehlik, Christian; Perlman, Harris

2015-10-16

expression of costimulatory CD86 on the Ly6C(high)CD11b(+)F4/80(+) splenic cells, and oral antibiotic treatment to remove microbiota prevents splenomegaly and lymphadenopathy in Cre (LysM) Casp8 (fl/fl) mice. Further, caspase-8-deficient macrophages are hyperresponsive to TLR activation and exhibit aberrant M1 macrophage polarization due to RIPK activity. These data demonstrate that caspase-8 functions uniquely in macrophages by controlling the response to TLR activation and macrophage polarization in an RIPK-dependent manner.

Evaluation of in vitro macrophage differentiation during space flight

NASA Astrophysics Data System (ADS)

Ortega, M. Teresa; Lu, Nanyan; Chapes, Stephen K.

2012-05-01

We differentiated mouse bone marrow cells in the presence of recombinant macrophage colony stimulating (rM-CSF) factor for 14 days during the flight of space shuttle Space Transportation System (STS)-126. We tested the hypothesis that the receptor expression for M-CSF, c-Fms was reduced. We used flow cytometry to assess molecules on cells that were preserved during flight to define the differentiation state of the developing bone marrow macrophages; including CD11b, CD31, CD44, Ly6C, Ly6G, F4/80, Mac2, c-Fos as well as c-Fms. In addition, RNA was preserved during the flight and was used to perform a gene microarray. We found that there were significant differences in the number of macrophages that developed in space compared to controls maintained on Earth. We found that there were significant changes in the distribution of cells that expressed CD11b, CD31, F4/80, Mac2, Ly6C and c-Fos. However, there were no changes in c-Fms expression and no consistent pattern of advanced or retarded differentiation during space flight. We also found a pattern of transcript levels that would be consistent with a relatively normal differentiation outcome but increased proliferation by the bone marrow macrophages that were assayed after 14 days of space flight. There also was a surprising pattern of space flight influence on genes of the coagulation pathway. These data confirm that a space flight can have an impact on the in vitro development of macrophages from mouse bone marrow cells.

Evaluation of in vitro macrophage differentiation during space flight.

PubMed

Ortega, M Teresa; Lu, Nanyan; Chapes, Stephen K

2012-05-15

We differentiated mouse bone marrow cells in the presence of recombinant macrophage colony stimulating (rM-CSF) factor for 14 days during the flight of space shuttle Space Transportation System (STS)-126. We tested the hypothesis that the receptor expression for M-CSF, c-Fms was reduced. We used flow cytometry to assess molecules on cells that were preserved during flight to define the differentiation state of the developing bone marrow macrophages; including CD11b, CD31, CD44, Ly6C, Ly6G, F4/80, Mac2, c-Fos as well as c-Fms. In addition, RNA was preserved during the flight and was used to perform a gene microarray. We found that there were significant differences in the number of macrophages that developed in space compared to controls maintained on Earth. We found that there were significant changes in the distribution of cells that expressed CD11b, CD31, F4/80, Mac2, Ly6C and c-Fos. However, there were no changes in c-Fms expression and no consistent pattern of advanced or retarded differentiation during space flight. We also found a pattern of transcript levels that would be consistent with a relatively normal differentiation outcome but increased proliferation by the bone marrow macrophages that were assayed after 14 days of space flight. There also was a surprising pattern of space flight influence on genes of the coagulation pathway. These data confirm that a space flight can have an impact on the in vitro development of macrophages from mouse bone marrow cells.

The metabolic ER stress sensor IRE1α suppresses alternative activation of macrophages and impairs energy expenditure in obesity.

PubMed

Shan, Bo; Wang, Xiaoxia; Wu, Ying; Xu, Chi; Xia, Zhixiong; Dai, Jianli; Shao, Mengle; Zhao, Feng; He, Shengqi; Yang, Liu; Zhang, Mingliang; Nan, Fajun; Li, Jia; Liu, Jianmiao; Liu, Jianfeng; Jia, Weiping; Qiu, Yifu; Song, Baoliang; Han, Jing-Dong J; Rui, Liangyou; Duan, Sheng-Zhong; Liu, Yong

2017-05-01

Obesity is associated with metabolic inflammation and endoplasmic reticulum (ER) stress, both of which promote metabolic disease progression. Adipose tissue macrophages (ATMs) are key players orchestrating metabolic inflammation, and ER stress enhances macrophage activation. However, whether ER stress pathways underlie ATM regulation of energy homeostasis remains unclear. Here, we identified inositol-requiring enzyme 1α (IRE1α) as a critical switch governing M1-M2 macrophage polarization and energy balance. Myeloid-specific IRE1α abrogation in Ern1 f/f ; Lyz2-Cre mice largely reversed high-fat diet (HFD)-induced M1-M2 imbalance in white adipose tissue (WAT) and blocked HFD-induced obesity, insulin resistance, hyperlipidemia and hepatic steatosis. Brown adipose tissue (BAT) activity, WAT browning and energy expenditure were significantly higher in Ern1 f/f ; Lyz2-Cre mice. Furthermore, IRE1α ablation augmented M2 polarization of macrophages in a cell-autonomous manner. Thus, IRE1α senses protein unfolding and metabolic and immunological states, and consequently guides ATM polarization. The macrophage IRE1α pathway drives obesity and metabolic syndrome through impairing BAT activity and WAT browning.

CSF-1–dependant donor-derived macrophages mediate chronic graft-versus-host disease

PubMed Central

Alexander, Kylie A.; Flynn, Ryan; Lineburg, Katie E.; Kuns, Rachel D.; Teal, Bianca E.; Olver, Stuart D.; Lor, Mary; Raffelt, Neil C.; Koyama, Motoko; Leveque, Lucie; Le Texier, Laetitia; Melino, Michelle; Markey, Kate A.; Varelias, Antiopi; Engwerda, Christian; Serody, Jonathan S.; Janela, Baptiste; Ginhoux, Florent; Clouston, Andrew D.; Blazar, Bruce R.; Hill, Geoffrey R.; MacDonald, Kelli P.A.

2014-01-01

Chronic GVHD (cGVHD) is the major cause of late, nonrelapse death following stem cell transplantation and characteristically develops in organs such as skin and lung. Here, we used multiple murine models of cGVHD to investigate the contribution of macrophage populations in the development of cGVHD. Using an established IL-17–dependent sclerodermatous cGVHD model, we confirmed that macrophages infiltrating the skin are derived from donor bone marrow (F4/80+CSF-1R+CD206+iNOS–). Cutaneous cGVHD developed in a CSF-1/CSF-1R–dependent manner, as treatment of recipients after transplantation with CSF-1 exacerbated macrophage infiltration and cutaneous pathology. Additionally, recipients of grafts from Csf1r–/– mice had substantially less macrophage infiltration and cutaneous pathology as compared with those receiving wild-type grafts. Neither CCL2/CCR2 nor GM-CSF/GM-CSFR signaling pathways were required for macrophage infiltration or development of cGVHD. In a different cGVHD model, in which bronchiolitis obliterans is a prominent manifestation, F4/80+ macrophage infiltration was similarly noted in the lungs of recipients after transplantation, and lung cGVHD was also IL-17 and CSF-1/CSF-1R dependent. Importantly, depletion of macrophages using an anti–CSF-1R mAb markedly reduced cutaneous and pulmonary cGVHD. Taken together, these data indicate that donor macrophages mediate the development of cGVHD and suggest that targeting CSF-1 signaling after transplantation may prevent and treat cGVHD. PMID:25157821

Visualization of macrophage recruitment in head and neck carcinoma model using fluorine-19 magnetic resonance imaging.

PubMed

Khurana, Aman; Chapelin, Fanny; Xu, Hongyan; Acevedo, Joseph R; Molinolo, Alfred; Nguyen, Quyen; Ahrens, Eric T

2018-04-01

To evaluate the role of infiltrating macrophages in murine models of single and double mutation head and neck tumors using a novel fluorine-19 ( 19 F) MRI technology. Tumor cell lines single-hit/SCC4 or double-hit/Cal27, with mutations of TP53 and TP53 & FHIT, respectively, were injected bilaterally into the flanks of (n = 10) female mice. With tumors established, perfluorocarbon nanoemulsion was injected intravenously, which labels in situ predominantly monocytes and macrophages. Longitudinal spin density-weighted 19 F MRI data enabled quantification of the macrophage burden in tumor and surrounding tissue. The average number of 19 F atoms within the tumors was twice as high in the Cal27 group compared with SCC4 (3.9 × 10 19 and 2.0 × 10 19 19 F/tumor, respectively; P = 0.0034) two days after contrast injection, signifying increased tumor-associated macrophages in double-hit tumors. The difference was still significant 10 days after injection. Histology stains correlated with in vivo results, exhibiting numerous perfluorocarbon-labeled macrophages in double-hit tumors and to a lesser extent in single-hit tumors. This study helps to establish 19 F MRI as a method for quantifying immune cells in the tumor microenvironment, allowing distinction between double and single-hit head and neck tumors. This technique would be extremely valuable in the clinic for pretreatment planning, prognostics, and post-treatment surveillance. Magn Reson Med 79:1972-1980, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Quercetin ameliorates kidney injury and fibrosis by modulating M1/M2 macrophage polarization.

PubMed

Lu, Hong; Wu, Lianfeng; Liu, Leping; Ruan, Qingqing; Zhang, Xing; Hong, Weilong; Wu, Shijia; Jin, Guihua; Bai, Yongheng

2018-05-15

Interstitial inflammation is the main pathological feature in kidneys following injury, and the polarization of macrophages is involved in the process of inflammatory injury. Previous studies have shown that quercetin has a renal anti-inflammatory activity, but the potential molecular mechanism remains unknown. In obstructive kidneys, administration of quercetin inhibited tubulointerstitial injury and reduced the synthesis and release of inflammatory factors. Further study revealed that quercetin inhibited the infiltration of CD68+ macrophages in renal interstitium. Moreover, the decrease in levels of iNOS and IL-12, as well as the proportion of F4/80+/CD11b+/CD86+ macrophages, indicated quercetin-mediated inhibition of M1 macrophage polarization in the injured kidneys. In cultured macrophages, lipopolysaccharide-induced inflammatory polarization was suppressed by quercetin treatment, resulting in the reduction of the release of inflammatory factors. Notably, quercetin-induced inhibitory effects on inflammatory macrophage polarization were associated with down-regulated activities of NF-κB p65 and IRF5, and thus led to the inactivation of upstream signaling TLR4/Myd88. Interestingly, quercetin also inhibited the polarization of F4/80+/CD11b+/CD206+ M2 macrophages, and reduced excessive accumulation of extracellular matrix and interstitial fibrosis by antagonizing the TGF-β1/Smad2/3 signaling. Thus, quercetin ameliorates kidney injury via modulating macrophage polarization, and may have therapeutic potential for patients with kidney injury. Copyright © 2018 Elsevier Inc. All rights reserved.

Lymphatic vasculature mediates macrophage reverse cholesterol transport in mice.

PubMed

Martel, Catherine; Li, Wenjun; Fulp, Brian; Platt, Andrew M; Gautier, Emmanuel L; Westerterp, Marit; Bittman, Robert; Tall, Alan R; Chen, Shu-Hsia; Thomas, Michael J; Kreisel, Daniel; Swartz, Melody A; Sorci-Thomas, Mary G; Randolph, Gwendalyn J

2013-04-01

Reverse cholesterol transport (RCT) refers to the mobilization of cholesterol on HDL particles (HDL-C) from extravascular tissues to plasma, ultimately for fecal excretion. Little is known about how HDL-C leaves peripheral tissues to reach plasma. We first used 2 models of disrupted lymphatic drainage from skin--1 surgical and the other genetic--to quantitatively track RCT following injection of [3H]-cholesterol-loaded macrophages upstream of blocked or absent lymphatic vessels. Macrophage RCT was markedly impaired in both models, even at sites with a leaky vasculature. Inhibited RCT was downstream of cholesterol efflux from macrophages, since macrophage efflux of a fluorescent cholesterol analog (BODIPY-cholesterol) was not altered by impaired lymphatic drainage. We next addressed whether RCT was mediated by lymphatic vessels from the aortic wall by loading the aortae of donor atherosclerotic Apoe-deficient mice with [2H]6-labeled cholesterol and surgically transplanting these aortae into recipient Apoe-deficient mice that were treated with anti-VEGFR3 antibody to block lymphatic regrowth or with control antibody to allow such regrowth. [2H]-Cholesterol was retained in aortae of anti-VEGFR3-treated mice. Thus, the lymphatic vessel route is critical for RCT from multiple tissues, including the aortic wall. These results suggest that supporting lymphatic transport function may facilitate cholesterol clearance in therapies aimed at reversing atherosclerosis.

The Role of Macrophages in Acute and Chronic Wound Healing and Interventions to Promote Pro-wound Healing Phenotypes

PubMed Central

Krzyszczyk, Paulina; Schloss, Rene; Palmer, Andre; Berthiaume, François

2018-01-01

Macrophages play key roles in all phases of adult wound healing, which are inflammation, proliferation, and remodeling. As wounds heal, the local macrophage population transitions from predominantly pro-inflammatory (M1-like phenotypes) to anti-inflammatory (M2-like phenotypes). Non-healing chronic wounds, such as pressure, arterial, venous, and diabetic ulcers indefinitely remain in inflammation—the first stage of wound healing. Thus, local macrophages retain pro-inflammatory characteristics. This review discusses the physiology of monocytes and macrophages in acute wound healing and the different phenotypes described in the literature for both in vitro and in vivo models. We also discuss aberrations that occur in macrophage populations in chronic wounds, and attempts to restore macrophage function by therapeutic approaches. These include endogenous M1 attenuation, exogenous M2 supplementation and endogenous macrophage modulation/M2 promotion via mesenchymal stem cells, growth factors, biomaterials, heme oxygenase-1 (HO-1) expression, and oxygen therapy. We recognize the challenges and controversies that exist in this field, such as standardization of macrophage phenotype nomenclature, definition of their distinct roles and understanding which phenotype is optimal in order to promote healing in chronic wounds. PMID:29765329

Macrophages as drug delivery vehicles for photochemical internalization (Conference Presentation)

NASA Astrophysics Data System (ADS)

Madsen, Steen J.; Gonzalez, Jonathan; Molina, Stephanie; Kumar Nair, Rohit; Hirschberg, Henry

2017-02-01

Targeted delivery of chemotherapeutic drugs to tumor sites is a major challenge in cancer chemotherapy. Cell-based vectorization of therapeutic agents has great potential for cancer therapy in that it can target and maintain an elevated concentration of therapeutic agents at the tumor site and prevent their spread into healthy tissue. The use of circulating cells such as monocytes/macrophages (Ma) offers several advantages compared to nanoparticles as targeted drug delivery vehicles. Ma can be easily obtained from the patient, loaded in vitro with drugs and reinjected into the blood stream. Ma can selectively cross the partially compromised blood-brain barrier surrounding brain tumors and are known to actively migrate to tumors, drawn by chemotactic factors, including hypoxic regions where conventional chemo and radiation therapy are least effective. The utility of Ma as targeted drug delivery vehicles for photochemical internalization (PCI) of tumors was investigated in this study. In vitro studies were conducted using a mixture of F98 rat glioma cells and rat macrophages loaded with a variety of chemotherapeutic agents including bleomycin and 5-fluorouracil. Preliminary data show that macrophages are resistant to both chemotherapeutics while significant toxicity is observed for F98 cells exposed to both drugs. Co-incubation of F98 cells with loaded Ma results in significant F98 toxicity suggesting that Ma are releasing the drugs and, hence providing the rationale for their use as delivery vectors for cancer therapies such as PCI.

Novel technique for generating macrophage foam cells for in vitro reverse cholesterol transport studies[S

PubMed Central

Sengupta, Bhaswati; Narasimhulu, Chandrakala Aluganti; Parthasarathy, Sampath

2013-01-01

Generation of foam cells, an essential step for reverse cholesterol transport studies, uses the technique of receptor-dependent macrophage loading with radiolabeled acetylated LDL. In this study, we used the ability of a biologically relevant detergent molecule, lysophosphatidylcholine (lyso-PtdCho), to form mixed micelles with cholesterol or cholesteryl ester (CE) to generate macrophage foam cells. Fluorescent or radiolabeled cholesterol/lyso-PtdCho mixed micelles were prepared and incubated with RAW 264.7 or mouse peritoneal macrophages. Results showed that such micelles were quite stable at 4°C and retained the solubilized cholesterol during one month of storage. Macrophages incubated with cholesterol or CE (unlabeled, fluorescently labeled, or radiolabeled)/lyso-PtdCho mixed micelles accumulated CE as documented by microscopy, lipid staining, labeled oleate incorporation, and by TLC. Such foam cells unloaded cholesterol when incubated with HDL but not with oxidized HDL. We propose that stable cholesterol or CE/lyso-PtdCho micelles would offer advantages over existing methods. PMID:24115226

Effect of mineral trioxide aggregate on cytokine production by peritoneal macrophages.

PubMed

Rezende, T M B; Vargas, D L; Cardoso, F P; Sobrinho, A P R; Vieira, L Q

2005-12-01

To test the effect of two commercial brands of grey mineral trioxide aggregate (ProRoot and MTA-Angelus) on cytokine production by M1 and M2 inflammatory macrophages. M1 (from C57BL/6 mice) and M2 peritoneal inflammatory macrophages (from C57BL/6 IL12p40-/- mice) were obtained and cultured in vitro in the presence of MTA. The cellular viability and the production of tumour necrosis factor-alpha, interleukin (IL)-12 and IL-10 in response to stimulation with interferon-gamma and Fusobacterium nucleatum or Peptostreptococcus anaerobius were evaluated. Data were analysed by Mann-Whitney, Kruskal-Wallis and anova tests. The cements did not interfere with cellular viability or with cytokine production by either type of macrophage. However, M2 macrophages produced higher levels of IL-10 when stimulated with F. nucleatum than M1 macrophages (P < 0.05). The brands of MTA evaluated did not interfere in the cytokine response by M1 or M2 macrophages to the two bacteria tested. However, a difference in cytokine production between the two types of macrophages was found.

Brain 18F-FDG PET Metabolic Abnormalities in Patients with Long-Lasting Macrophagic Myofascitis.

PubMed

Van Der Gucht, Axel; Aoun Sebaiti, Mehdi; Guedj, Eric; Aouizerate, Jessie; Yara, Sabrina; Gherardi, Romain K; Evangelista, Eva; Chalaye, Julia; Cottereau, Anne-Ségolène; Verger, Antoine; Bachoud-Levi, Anne-Catherine; Abulizi, Mukedaisi; Itti, Emmanuel; Authier, François-Jérôme

2017-03-01

The aim of this study was to characterize brain metabolic abnormalities in patients with macrophagic myofascitis (MMF) and the relationship with cognitive dysfunction through the use of PET with 18 F-FDG. Methods: 18 F-FDG PET brain imaging and a comprehensive battery of neuropsychological tests were performed in 100 consecutive MMF patients (age [mean ± SD], 45.9 ± 12 y; 74% women). Images were analyzed with statistical parametric mapping (SPM12). Through the use of analysis of covariance, all 18 F-FDG PET brain images of MMF patients were compared with those of a reference population of 44 healthy subjects similar in age (45.4 ± 16 y; P = 0.87) and sex (73% women; P = 0.88). The neuropsychological assessment identified 4 categories of patients: those with no significant cognitive impairment ( n = 42), those with frontal subcortical (FSC) dysfunction ( n = 29), those with Papez circuit dysfunction ( n = 22), and those with callosal disconnection ( n = 7). Results: In comparison with healthy subjects, the whole population of patients with MMF exhibited a spatial pattern of cerebral glucose hypometabolism ( P < 0.001) involving the occipital lobes, temporal lobes, limbic system, cerebellum, and frontoparietal cortices, as shown by analysis of covariance. The subgroup of patients with FSC dysfunction exhibited a larger extent of involved areas (35,223 voxels vs. 13,680 voxels in the subgroup with Papez circuit dysfunction and 5,453 voxels in patients without cognitive impairment). Nonsignificant results were obtained for the last subgroup because of its small population size. Conclusion: Our study identified a peculiar spatial pattern of cerebral glucose hypometabolism that was most marked in MMF patients with FSC dysfunction. Further studies are needed to determine whether this pattern could represent a diagnostic biomarker of MMF in patients with chronic fatigue syndrome and cognitive dysfunction. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

The ineffectiveness of coumarin treatment on thermal oedema of macrophage-free rats.

PubMed Central

Piller, N. B.

1976-01-01

The administration of silica prevents coumarin-stimulated lysis of accumulated abnormal protein. This impairs the resolution of thermal oedema which is normally increased with coumarin administration. Evidence suggests that there is a rapid differentiation and infiltration of monocytes into the tissues and that these are selectively retained. This is aided by coumarin which increases tissue permeability. Coumarin also injures the vascular endothelium of some vessels, allowing extra protein and fluid into the tissues. Death of recently differentiated macrophages and subsequent release of their lysosomal contents into the extra-cellular spaces may be responsible for the changes in serum enzyme levels. It would seem that macrophages are the only cells in which coumarin stimulates increased phagocytosis, enzyme production and proteolysis. PMID:178336

CCAAT/enhancer-binding protein beta inhibits proliferation in monocytic cells by affecting the retinoblastoma protein/E2F/cyclin E pathway but is not directly required for macrophage morphology.

PubMed

Gutsch, Romina; Kandemir, Judith D; Pietsch, Daniel; Cappello, Christian; Meyer, Johann; Simanowski, Kathrin; Huber, René; Brand, Korbinian

2011-07-01

Monocytic differentiation is orchestrated by complex networks that are not fully understood. This study further elucidates the involvement of transcription factor CCAAT/enhancer-binding protein β (C/EBPβ). Initially, we demonstrated a marked increase in nuclear C/EBPβ-liver-enriched activating protein* (LAP*)/liver-enriched activating protein (LAP) levels and LAP/liver-enriched inhibiting protein (LIP) ratios in phorbol 12-myristate 13-acetate (PMA)-treated differentiating THP-1 premonocytic cells accompanied by reduced proliferation. To directly study C/EBPβ effects on monocytic cells, we generated novel THP-1-derived (low endogenous C/EBPβ) cell lines stably overexpressing C/EBPβ isoforms. Most importantly, cells predominantly overexpressing LAP* (C/EBPβ-long), but not those overexpressing LIP (C/EBPβ-short), exhibited a reduced proliferation, with no effect on morphology. PMA-induced inhibition of proliferation was attenuated in C/EBPβ-short cells. In C/EBPβ(WT) macrophage-like cells (high endogenous C/EBPβ), we measured a reduced proliferation/cycling index compared with C/EBPβ(KO). The typical macrophage morphology was only observed in C/EBPβ(WT), whereas C/EBPβ(KO) stayed round. C/EBPα did not compensate for C/EBPβ effects on proliferation/morphology. Serum reduction, an independent approach known to inhibit proliferation, induced macrophage morphology in C/EBPβ(KO) macrophage-like cells but not THP-1. In PMA-treated THP-1 and C/EBPβ-long cells, a reduced phosphorylation of cell cycle repressor retinoblastoma was found. In addition, C/EBPβ-long cells showed reduced c-Myc expression accompanied by increased CDK inhibitor p27 and reduced cyclin D1 levels. Finally, C/EBPβ-long and C/EBPβ(WT) cells exhibited low E2F1 and cyclin E levels, and C/EBPβ overexpression was found to inhibit cyclin E1 promoter-dependent transcription. Our results suggest that C/EBPβ reduces monocytic proliferation by affecting the retinoblastoma/E2F/cyclin E

LPS-inducible factor(s) from activated macrophages mediates cytolysis of Naegleria fowleri amoebae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cleary, S.F.; Marciano-Cabral, F.

1986-03-01

Soluble cytolytic factors of macrophage origin have previously been described with respect to their tumoricidal activity. The purpose of this study was to investigate the mechanism and possible factor(s) responsible for cytolysis of the amoeba Naegleria fowleri by activated peritoneal macrophages from B6C3F1 mice. Macrophages or conditioned medium (CM) from macrophage cultures were incubated with /sup 3/H-Uridine labeled amoebae. Percent specific release of label served as an index of cytolysis. Bacille Calmette-Guerin (BCG) and Corynebacterium parvum macrophages demonstrated significant cytolysis of amoebae at 24 h with an effector to target ratio of 10:1. Treatment of macrophages with inhibitors of RNAmore » or protein synthesis blocked amoebicidal activity. Interposition of a 1 ..mu..m pore membrane between macrophages and amoebae inhibited killing. Inhibition in the presence of the membrane was overcome by stimulating the macrophages with LPS. CM from SPS-stimulated, but not unstimulated, cultures of activated macrophages was cytotoxic for amoebae. The activity was heat sensitive and was recovered from ammonium sulfate precipitation of the CM. Results indicate that amoebicidal activity is mediated by a protein(s) of macrophage origin induced by target cell contact or stimulation with LPS.« less

Culture of Macrophage Colony-stimulating Factor Differentiated Human Monocyte-derived Macrophages.

PubMed

Jin, Xueting; Kruth, Howard S

2016-06-30

A protocol is presented for cell culture of macrophage colony-stimulating factor (M-CSF) differentiated human monocyte-derived macrophages. For initiation of experiments, fresh or frozen monocytes are cultured in flasks for 1 week with M-CSF to induce their differentiation into macrophages. Then, the macrophages can be harvested and seeded into culture wells at required cell densities for carrying out experiments. The use of defined numbers of macrophages rather than defined numbers of monocytes to initiate macrophage cultures for experiments yields macrophage cultures in which the desired cell density can be more consistently attained. Use of cryopreserved monocytes reduces dependency on donor availability and produces more homogeneous macrophage cultures.

Composition and anti-inflammatory effect of polysaccharides from Sargassum horneri in RAW264.7 macrophages.

PubMed

Wen, Zheng-Shun; Xiang, Xing-Wei; Jin, Huo-Xi; Guo, Xiang-Yang; Liu, Li-Jia; Huang, Yan-Na; OuYang, Xiao-Kun; Qu, You-Le

2016-07-01

Sulfated polysaccharides extracted from brown marine algae have been shown to possess a variety of biological activities. We assessed the potential activity of the sulfated polysaccharide from Sargassum horneri (SP) and its isolated two major components (fraction-1 (F1) and fraction-2 (F2)), on anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. In the present study, analysis of polysaccharide chemical composition found that the constituent ratios of sulfate ester and fucose in SP and F1 were 4.95% vs 7.6%, and 4.48% vs 55.9%, respectively, suggesting that F1 may be a major sulfated polysaccharide containing fucose. Meanwhile, our findings demonstrated that TNF-α secretion levels were significantly (P<0.05) decreased by SP and F1 treatments in LPS-stimulated RAW264.7 cells in a dose-dependent manner under the preventive and repair experimental models. Pro-/anti-inflammatory (TNF-α/IL-10) cytokines secretion ratios by LPS-stimulated RAW264.7 macrophages were significantly (P<0.05) inhibited by SP and F1 treatments, particularly by F1 (at high dose, 200μg/ml). Moreover, NO release and iNOS activity were significantly (P<0.05) inhibited by F1. Collectively, the present study suggested that purified component, F1 from SP, had strong anti-inflammatory effects on LPS-stimulated RAW264.7 macrophages in the preventive and repair manner through inhibiting TNF-α secretion levels and NO release. Copyright © 2016 Elsevier B.V. All rights reserved.

Increased Tim-3 expression alleviates liver injury by regulating macrophage activation in MCD-induced NASH mice.

PubMed

Du, Xianhong; Wu, Zhuanchang; Xu, Yong; Liu, Yuan; Liu, Wen; Wang, Tixiao; Li, Chunyang; Zhang, Cuijuan; Yi, Fan; Gao, Lifen; Liang, Xiaohong; Ma, Chunhong

2018-05-07

As an immune checkpoint, Tim-3 plays roles in the regulation of both adaptive and innate immune cells including macrophages and is greatly involved in chronic liver diseases. However, the precise roles of Tim-3 in nonalcoholic steatohepatitis (NASH) remain unstated. In the current study, we analyzed Tim-3 expression on different subpopulations of liver macrophages and further investigated the potential roles of Tim-3 on hepatic macrophages in methionine and choline-deficient diet (MCD)-induced NASH mice. The results of flow cytometry demonstrated the significantly increased expression of Tim-3 on all detected liver macrophage subsets in MCD mice, including F4/80 + CD11b + , F4/80 + CD68 + , and F4/80 + CD169 + macrophages. Remarkably, Tim-3 knockout (KO) significantly accelerated MCD-induced liver steatosis, displaying higher serum ALT, larger hepatic vacuolation, more liver lipid deposition, and more severe liver fibrosis. Moreover, compared with wild-type C57BL/6 mice, Tim-3 KO MCD mice demonstrated an enhanced expression of NOX2, NLRP3, and caspase-1 p20 together with increased generation of IL-1β and IL-18 in livers. In vitro studies demonstrated that Tim-3 negatively regulated the production of reactive oxygen species (ROS) and related downstream pro-inflammatory cytokine secretion of IL-1β and IL-18 in macrophages. Exogenous administration of N-Acetyl-L-cysteine (NAC), a small molecular inhibitor of ROS, remarkably suppressed caspase-1 p20 expression and IL-1β and IL-18 production in livers of Tim-3 KO mice, thus significantly reducing the severity of steatohepatitis induced by MCD. In conclusion, Tim-3 is a promising protector in MCD-induced steatohepatitis by controlling ROS and the associated pro-inflammatory cytokine production in macrophages.

In Vitro Response of Guinea Pig Peritoneal Macrophages to Legionella pneumophila

DTIC Science & Technology

1981-03-01

In Vitro Responlse of Guinea Pig Peritoneal Macrophages to Legionella pneumophila It. A. KISIIIMi~O~’ .1. Ii.,W11ITE, F. G. SIREY, V. (U.1 Mc(GANN, R...Tlhe inter- act ion between L. lincumnophila andl( peritoneal macrophages front normial guinea pigs or front animials that had survived infection was...roagglujtiniat titer) guinea pig serum to The purp~ose of this study "as to investigate contain approximately 108 organisms per ml. the phagocytic and

Macrophage recruitment, but not interleukin 1 beta activation, enhances noise-induced hearing damage.

PubMed

Mizushima, Yu; Fujimoto, Chisato; Kashio, Akinori; Kondo, Kenji; Yamasoba, Tatsuya

2017-11-18

It has been suggested that macrophages or inflammatory monocytes participate in the pathology of noise-induced hearing loss (NIHL), but it is unclear how extensively these cells contribute to the development of temporary and/or permanent NIHL. To address this question, we used clodronate liposomes to deplete macrophages and monocytes. After clodronate liposome injection, mice were exposed to 4-kHz octave band noise at 121 dB for 4 h. Compared to vehicle-injected controls, clodronate-treated mice exhibited significantly reduced permanent threshold shifts at 4 and 8 kHz and significantly smaller outer hair cell losses in the lower-apical cochlear turn. Following noise exposure, the stria vascularis had significantly more cells expressing the macrophage-specific protein F4/80, and this effect was significantly suppressed by clodronate treatment. These F4/80-positive cells expressed interleukin 1 beta (IL-1β), which noise exposure activated. However, IL-1β deficient mice did not exhibit significant resistance to intense noise when compared to wild-type mice. These findings suggest that macrophages that enter the cochlea after noise exposure are involved in NIHL, whereas IL-1β inhibition does not reverse this cochlear damage. Therefore, macrophages may be a promising therapeutic target in human sensorineural hearing losses such as NIHL. Copyright © 2017 Elsevier Inc. All rights reserved.

Demonstration of early functional compromise of bone marrow derived hematopoietic progenitor cells during bovine neonatal pancytopenia through in vitro culture of bone marrow biopsies.

PubMed

Laming, Eleanor; Melzi, Eleonora; Scholes, Sandra F E; Connelly, Maira; Bell, Charlotte R; Ballingall, Keith T; Dagleish, Mark P; Rocchi, Mara S; Willoughby, Kim

2012-10-30

Bovine neonatal pancytopenia (BNP) is a syndrome characterised by thrombocytopenia associated with marked bone marrow destruction in calves, widely reported since 2007 in several European countries and since 2011 in New Zealand. The disease is epidemiologically associated with the use of an inactivated bovine virus diarrhoea (BVD) vaccine and is currently considered to be caused by absorption of colostral antibody produced by some vaccinated cows ("BNP dams"). Alloantibodies capable of binding to the leukocyte surface have been detected in BNP dams and antibodies recognising bovine MHC class I and β-2-microglobulin have been detected in vaccinated cattle. In this study, calves were challenged with pooled colostrum collected from BNP dams or from non-BNP dams and their bone marrow hematopoietic progenitor cells (HPC) cultured in vitro from sternal biopsies taken at 24 hours and 6 days post-challenge. Clonogenic assay demonstrated that CFU-GEMM (colony forming unit-granulocyte/erythroid/macrophage/megakaryocyte; pluripotential progenitor cell) colony development was compromised from HPCs harvested as early as 24 hour post-challenge. By 6 days post challenge, HPCs harvested from challenged calves failed to develop CFU-E (erythroid) colonies and the development of both CFU-GEMM and CFU-GM (granulocyte/macrophage) was markedly reduced. This study suggests that the bone marrow pathology and clinical signs associated with BNP are related to an insult which compromises the pluripotential progenitor cell within the first 24 hours of life but that this does not initially include all cell types.

Macrophage Activation Mechanisms in Human Monocytic Cell Line-derived Macrophages.

PubMed

Sumiya, Yu; Ishikawa, Mami; Inoue, Takahiro; Inui, Toshio; Kuchiike, Daisuke; Kubo, Kentaro; Uto, Yoshihiro; Nishikata, Takahito

2015-08-01

Although the mechanisms of macrophage activation are important for cancer immunotherapy, they are poorly understood. Recently, easy and robust assay systems for assessing the macrophage-activating factor (MAF) using monocytic cell line-derived macrophages were established. Gene-expression profiles of U937- and THP-1-derived macrophages were compared using gene expression microarray analysis and their responses against several MAFs were examined by in vitro experiments. Activated states of these macrophages could not be assigned to a specific sub-type but showed, however, different unique characteristics. The unique of monocytic cell line-derived macrophages could provide clues to understand the activation mechanism of macrophages and, therefore, help to develop effective cancer immunotherapy with MAFs. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Imaging macrophage distribution and density in mammary tumors and lung metastases using fluorine-19 MRI cell tracking.

PubMed

Makela, Ashley V; Foster, Paula J

2018-09-01

The presence of tumor-associated macrophages (TAMs) correlates with breast cancer progression and metastatic spread. Metastasis-associated macrophages (MAMs) are also recruited to distant sites, where they support metastatic growth. In this study, we demonstrate that in vivo fluorine-19 ( 19 F)-based MRI cell tracking can evaluate the density and distribution of macrophages within murine breast cancer tumors and associated metastases. Three murine breast cancer cell lines with different metastatic potentials (4T1, 168FARN, and 67NR) were implanted into the mammary fat pad in mice. In vivo whole body 19 F MRI was performed on tumor-bearing mice 24 hours post-intravenous injection of a perfluorocarbon (PFC) agent, which was taken up by macrophages in situ. TAMs were detected mainly in the periphery of primary tumors, and higher numbers of TAMs were detected in the more aggressive 4T1 tumors. Tumors had significantly greater 19 F spins/mm 3 when they were smaller, suggesting more TAM infiltration in early-stage tumors. 19 F signal was observed within lung metastases in mice with 4T1 tumors, and fluorescence microscopy confirmed the presence of PFC-positive macrophages. This study shows for the first time proof of the ability to use MRI cell tracking to visualize MAMs in the lungs. The ability to detect and monitor the number of TAMs in individual tumors with 19 F MRI would allow for identification of breast tumors with heavy infiltration of TAMs and could be used as a biomarker for decisions about how to best treat these patients as well as for monitoring responses to therapy. Magn Reson Med 80:1138-1147, 2018. © 2018 International Society for Magnetic Resonance in Medicine. © 2018 International Society for Magnetic Resonance in Medicine.

Emodin Bidirectionally Modulates Macrophage Polarization and Epigenetically Regulates Macrophage Memory.

PubMed

Iwanowycz, Stephen; Wang, Junfeng; Altomare, Diego; Hui, Yvonne; Fan, Daping

2016-05-27

Macrophages are pleiotropic cells capable of performing a broad spectrum of functions. Macrophage phenotypes are classified along a continuum between the extremes of proinflammatory M1 macrophages and anti-inflammatory M2 macrophages. The seemingly opposing functions of M1 and M2 macrophages must be tightly regulated for an effective and proper response to foreign molecules or damaged tissue. Excessive activation of either M1 or M2 macrophages contributes to the pathology of many diseases. Emodin is a Chinese herb-derived compound and has shown potential to inhibit inflammation in various settings. In this study, we tested the ability of emodin to modulate the macrophage response to both M1 and M2 stimuli. Primary mouse macrophages were stimulated with LPS/IFNγ or IL4 with or without emodin, and the effects of emodin on gene transcription, cell signaling pathways, and histone modifications were examined by a variety of approaches, including microarray, quantitative real-time PCR, Western blotting, chromatin immunoprecipitation, and functional assays. We found that emodin bidirectionally tunes the induction of LPS/IFNγ- and IL4-responsive genes through inhibiting NFκB/IRF5/STAT1 signaling and IRF4/STAT6 signaling, respectively. Thereby, emodin modulates macrophage phagocytosis, migration, and NO production. Furthermore, emodin inhibited the removal of H3K27 trimethylation (H3K27m3) marks and the addition of H3K27 acetylation (H3K27ac) marks on genes required for M1 or M2 polarization of macrophages. In conclusion, our data suggest that emodin is uniquely able to suppress the excessive response of macrophages to both M1 and M2 stimuli and therefore has the potential to restore macrophage homeostasis in various pathologies. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Emodin Bidirectionally Modulates Macrophage Polarization and Epigenetically Regulates Macrophage Memory*

PubMed Central

Iwanowycz, Stephen; Wang, Junfeng; Altomare, Diego; Hui, Yvonne; Fan, Daping

2016-01-01

Macrophages are pleiotropic cells capable of performing a broad spectrum of functions. Macrophage phenotypes are classified along a continuum between the extremes of proinflammatory M1 macrophages and anti-inflammatory M2 macrophages. The seemingly opposing functions of M1 and M2 macrophages must be tightly regulated for an effective and proper response to foreign molecules or damaged tissue. Excessive activation of either M1 or M2 macrophages contributes to the pathology of many diseases. Emodin is a Chinese herb-derived compound and has shown potential to inhibit inflammation in various settings. In this study, we tested the ability of emodin to modulate the macrophage response to both M1 and M2 stimuli. Primary mouse macrophages were stimulated with LPS/IFNγ or IL4 with or without emodin, and the effects of emodin on gene transcription, cell signaling pathways, and histone modifications were examined by a variety of approaches, including microarray, quantitative real-time PCR, Western blotting, chromatin immunoprecipitation, and functional assays. We found that emodin bidirectionally tunes the induction of LPS/IFNγ- and IL4-responsive genes through inhibiting NFκB/IRF5/STAT1 signaling and IRF4/STAT6 signaling, respectively. Thereby, emodin modulates macrophage phagocytosis, migration, and NO production. Furthermore, emodin inhibited the removal of H3K27 trimethylation (H3K27m3) marks and the addition of H3K27 acetylation (H3K27ac) marks on genes required for M1 or M2 polarization of macrophages. In conclusion, our data suggest that emodin is uniquely able to suppress the excessive response of macrophages to both M1 and M2 stimuli and therefore has the potential to restore macrophage homeostasis in various pathologies. PMID:27008857

Increased choline uptake in macrophages and prostate cancer cells does not allow for differentiation between benign and malignant prostate pathologies.

PubMed

Schwarz, Timo; Seidl, Christof; Schiemann, Matthias; Senekowitsch-Schmidtke, Reingard; Krause, Bernd Joachim

2016-06-01

Inflammatory cells may contribute to the choline uptake in different prostate pathologies. The aim of this study was (i) to assess if inflammatory cells incorporate choline and (ii) to potentially detect differences compared to FDG uptake. Therefore we investigated the uptake of [(3)H]choline and [(18)F]FDG in human prostate carcinoma cells and human inflammatory cells. Macrophages were cultured from isolated mononuclear cells, gained by density gradient centrifugation of human buffy coats. T-lymphocytes, B-lymphocytes and granulocytes were enriched by density gradient centrifugation before cell sorting by means of flow cytometry was performed. [(3)H]choline and [(18)F]FDG uptake of isolated inflammatory cells as well as of LNCaP and PC-3 human prostate carcinoma cells was assessed simultaneously in dual tracer uptake experiments. Macrophages showed highest [(3)H]choline and [(18)F]FDG uptake compared to the tracer uptake rates of leukocytes. [(3)H]choline uptake of macrophages was in the same range as in prostate cancer cells. Lipopolysaccharide stimulation of macrophages resulted in an increase of [(18)F]FDG uptake in macrophages, but not in an increased [(3)H]choline uptake. The high [(3)H]choline uptake in macrophages may be a source of false-positive PET results in diagnosis of prostate cancer by choline-PET/CT. As already known from FDG-PET, discrimination between tumor and inflammation in prostate cancer patients is not possible via choline-PET. The application of choline-PET for reliable primary prostate cancer detection and delineation has to be queried. Copyright © 2016 Elsevier Inc. All rights reserved.

Nanoparticles Containing Curcumin Useful for Suppressing Macrophages In Vivo in Mice

PubMed Central

Amano, Chie; Minematsu, Hideki; Fujita, Kazuyo; Iwashita, Shinki; Adachi, Masaki; Igarashi, Koichi; Hinuma, Shuji

2015-01-01

To explore a novel method using liposomes to suppress macrophages, we screened food constituents through cell culture assays. Curcumin was one of the strongest compounds exhibiting suppressive effects on macrophages. We subsequently tried various methods to prepare liposomal curcumin, and eventually succeeded in preparing liposomes with sufficient amounts of curcumin to suppress macrophages by incorporating a complex of curcumin and bovine serum albumin. The diameter of the resultant nanoparticles, the liposomes containing curcumin, ranged from 60 to 100 nm. Flow cytometric analyses revealed that after intraperitoneal administration of the liposomes containing curcumin into mice, these were incorporated mainly by macrophages positive for F4/80, CD36, and CD11b antigens. Peritoneal cells prepared from mice injected in vivo with the liposomes containing curcumin apparently decreased interleukin-6-producing activities. Major changes in body weight and survival rates in the mice were not observed after administrating the liposomes containing curcumin. These results indicate that the liposomes containing curcumin are safe and useful for the selective suppression of macrophages in vivo in mice. PMID:26361331

Binding and activation of major histocompatibility complex class II-deficient macrophages by staphylococcal exotoxins

NASA Technical Reports Server (NTRS)

Beharka, A. A.; Armstrong, J. W.; Iandolo, J. J.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

1994-01-01

Macrophages from C2D transgenic mice deficient in the expression of major histocompatibility complex (MHC) class II proteins were used to identify binding sites for superantigens distinct from the MHC class II molecule. Iodinated staphylococcal enterotoxins A and B (SEA and SEB) and exfoliative toxins A and B (ETA and ETB) bound to C2D macrophages in a concentration-dependent and competitive manner. All four toxins increased F-actin concentration within 30 s of their addition to C2D macrophages, indicating that signal transduction occurred in response to toxin in the absence of class II MHC. Furthermore, ETA, ETB, SEA, and, to a lesser extent, SEB induced C2D macrophages to produce interleukin 6. Several molecular species on C2D macrophages with molecular masses of 140, 97, 61, 52, 43, and 37 kDa bound SEA in immunoprecipitation experiments. These data indicate the presence of novel, functionally active toxin binding sites on murine macrophages distinct from MHC class II molecules.

Experimental Study of Dry Granular Flow and Impact Behavior Against a Rigid Retaining Wall

NASA Astrophysics Data System (ADS)

Jiang, Yuan-Jun; Towhata, Ikuo

2013-07-01

Shallow slope failure in mountainous regions is a common and emergent hazard in terms of its damage to important traffic routes and local communities. The impact of dry granular flows consisting of rock fragments and other particles resulting from shallow slope failures on retaining structures has yet to be systematically researched and is not covered by current design codes. As a preliminary study of the impact caused by dry granular flows, a series of dry granular impact experiments were carried out for one model of a retaining wall. It was indirectly verified that the total normal force exerted on a retaining wall consists of a drag force ( F d), a gravitational and frictional force ( F gf), and a passive earth force ( F p), and that the calculation of F d can be based on the empirical formula defined in NF EN Eurocode 1990 ( Eurocode structuraux. Base de calcul des structures, AFNOR La plaine Saint Denis, 2003). It was also indirectly verified that, for flow with Froude number from 6 to 11, the drag coefficient ( C d) can be estimated using the previously proposed empirical parameters.

Infiltrated Macrophages Die of Pneumolysin-Mediated Necroptosis following Pneumococcal Myocardial Invasion.

PubMed

Gilley, Ryan P; González-Juarbe, Norberto; Shenoy, Anukul T; Reyes, Luis F; Dube, Peter H; Restrepo, Marcos I; Orihuela, Carlos J

2016-05-01

Streptococcus pneumoniae (the pneumococcus) is capable of invading the heart. Herein we observed that pneumococcal invasion of the myocardium occurred soon after development of bacteremia and was continuous thereafter. Using immunofluorescence microscopy (IFM), we observed that S. pneumoniae replication within the heart preceded visual signs of tissue damage in cardiac tissue sections stained with hematoxylin and eosin. Different S. pneumoniae strains caused distinct cardiac pathologies: strain TIGR4, a serotype 4 isolate, caused discrete pneumococcus-filled microscopic lesions (microlesions), whereas strain D39, a serotype 2 isolate, was, in most instances, detectable only using IFM and was associated with foci of cardiomyocyte hydropic degeneration and immune cell infiltration. Both strains efficiently invaded the myocardium, but cardiac damage was entirely dependent on the pore-forming toxin pneumolysin only for D39. Early microlesions caused by TIGR4 and microlesions formed by a TIGR4 pneumolysin-deficient mutant were infiltrated with CD11b(+) and Ly6G-positive neutrophils and CD11b(+) and F4/80-positive (F4/80(+)) macrophages. We subsequently demonstrated that macrophages in TIGR4-infected hearts died as a result of pneumolysin-induced necroptosis. The effector of necroptosis, phosphorylated mixed-lineage kinase domain-like protein (MLKL), was detected in CD11b(+) and F4/80(+) cells associated with microlesions. Likewise, treatment of infected mice and THP-1 macrophages in vitro with the receptor-interacting protein 1 kinase (RIP1) inhibitor necrostatin-5 promoted the formation of purulent microlesions and blocked cell death, respectively. We conclude that pneumococci that have invaded the myocardium are an important cause of cardiac damage, pneumolysin contributes to cardiac damage in a bacterial strain-specific manner, and pneumolysin kills infiltrated macrophages via necroptosis, which alters the immune response. Copyright © 2016, American Society for

Infiltrated Macrophages Die of Pneumolysin-Mediated Necroptosis following Pneumococcal Myocardial Invasion

PubMed Central

Gilley, Ryan P.; González-Juarbe, Norberto; Shenoy, Anukul T.; Reyes, Luis F.; Dube, Peter H.; Restrepo, Marcos I.

2016-01-01

Streptococcus pneumoniae (the pneumococcus) is capable of invading the heart. Herein we observed that pneumococcal invasion of the myocardium occurred soon after development of bacteremia and was continuous thereafter. Using immunofluorescence microscopy (IFM), we observed that S. pneumoniae replication within the heart preceded visual signs of tissue damage in cardiac tissue sections stained with hematoxylin and eosin. Different S. pneumoniae strains caused distinct cardiac pathologies: strain TIGR4, a serotype 4 isolate, caused discrete pneumococcus-filled microscopic lesions (microlesions), whereas strain D39, a serotype 2 isolate, was, in most instances, detectable only using IFM and was associated with foci of cardiomyocyte hydropic degeneration and immune cell infiltration. Both strains efficiently invaded the myocardium, but cardiac damage was entirely dependent on the pore-forming toxin pneumolysin only for D39. Early microlesions caused by TIGR4 and microlesions formed by a TIGR4 pneumolysin-deficient mutant were infiltrated with CD11b+ and Ly6G-positive neutrophils and CD11b+ and F4/80-positive (F4/80+) macrophages. We subsequently demonstrated that macrophages in TIGR4-infected hearts died as a result of pneumolysin-induced necroptosis. The effector of necroptosis, phosphorylated mixed-lineage kinase domain-like protein (MLKL), was detected in CD11b+ and F4/80+ cells associated with microlesions. Likewise, treatment of infected mice and THP-1 macrophages in vitro with the receptor-interacting protein 1 kinase (RIP1) inhibitor necrostatin-5 promoted the formation of purulent microlesions and blocked cell death, respectively. We conclude that pneumococci that have invaded the myocardium are an important cause of cardiac damage, pneumolysin contributes to cardiac damage in a bacterial strain-specific manner, and pneumolysin kills infiltrated macrophages via necroptosis, which alters the immune response. PMID:26930705

Comparative analysis of the internalization of the macrophage receptor sialoadhesin in human and mouse primary macrophages and cell lines.

PubMed

De Schryver, Marjorie; Leemans, Annelies; Pintelon, Isabel; Cappoen, Davie; Maes, Louis; Caljon, Guy; Cos, Paul; Delputte, Peter L

2017-06-01

Sialoadhesin (Sn) is a surface receptor expressed on resident macrophages with the ability to bind with sialic acids. During inflammation, an upregulation of Sn is observed. Upon binding of monoclonal antibodies to Sn, the receptor becomes internalized and this has been observed in multiple species. The latter characteristic, combined with the strong upregulation of Sn on inflammatory macrophages and the fact that Sn-positive macrophages contribute to certain inflammatory diseases, makes Sn an interesting entry portal for phenotype-modulating or cytotoxic drugs. Such drugs or toxins can be linked to Sn-specific antibodies which should enable their targeted uptake by macrophages. However, the activity of such drugs depends not only on their internalization but also on the intracellular trafficking and final fate in the endolysosomal system. Although information is available for porcine Sn, the detailed mechanisms of human and mouse Sn internalization and subsequent intracellular trafficking are currently unknown. To allow development of Sn-targeted therapies, differences across species and cellular background need to be characterized in more detail. In the current report, we show that internalization of human and mouse Sn is dynamin-dependent and clathrin-mediated, both in primary macrophages and CHO cell lines expressing a recombinant Sn. In primary macrophages, internalized Sn-specific F(ab') 2 fragments are located mostly in the early endosomes. With Fc containing Sn-specific antibodies, there is a slight shift towards lysosomal localization in mouse macrophages, possibly because of an interaction with Fc receptors. Surprisingly, in CHO cell lines expressing Sn, there is a predominant lysosomal localization. Our results show that the mechanism of Sn internalization and intracellular trafficking is concurrent in the tested species. The cellular background in which Sn is expressed and the type of antibody used can affect the intracellular fate, which in turn can

Renal F4/80+CD11c+ Mononuclear Phagocytes Display Phenotypic and Functional Characteristics of Macrophages in Health and in Adriamycin Nephropathy

PubMed Central

Wang, Yiping; Wang, Xin Maggie; Lu, Junyu; Lee, Vincent W.S.; Ye, Qianling; Nguyen, Hanh; Zheng, Guoping; Zhao, Ye; Alexander, Stephen I.; Harris, David C.H.

2015-01-01

Conventional markers of macrophages (Mфs) and dendritic cells (DCs) lack specificity and often overlap, leading to confusion and controversy regarding the precise function of these cells in kidney and other diseases. This study aimed to identify the phenotype and function of renal mononuclear phagocytes (rMPs) expressing key markers of both Mфs and DCs. F4/80+CD11c+ cells accounted for 45% of total rMPs in normal kidneys and in those from mice with Adriamycin nephropathy (AN). Despite expression of the DC marker CD11c, these double-positive rMPs displayed the features of Mфs, including Mф-like morphology, high expression of CD68, CD204, and CD206, and high phagocytic ability but low antigen-presenting ability. F4/80+CD11c+ cells were found in the cortex but not in the medulla of the kidney. In AN, F4/80+CD11c+ cells displayed an M1 Mф phenotype with high expression of inflammatory mediators and costimulatory factors. Adoptive transfer of F4/80+CD11c+ cells separated from diseased kidney aggravated renal injury in AN mice. Furthermore, adoptive transfer of common progenitors revealed that kidney F4/80+CD11c+ cells were derived predominantly from monocytes, but not from pre-DCs. In conclusion, renal F4/80+CD11c+ cells are a major subset of rMPs and display Mф-like phenotypic and functional characteristics in health and in AN. PMID:25012165

Effects of the Subaleurone Layer of Rice on Macrophage Activation and Protection of Pollen Allergy in a Murine Model.

PubMed

Tamura, Yuki; Inagawa, Hiroyuki; Nakata, Yoko; Kohchi, Chie; Soma, Gen-Ichiro

2015-08-01

Oral intake of lipopolysaccharide (LPS) has been demonstrated to be effective in the prevention of various diseases. We have found that the subaleurone layer of rice contains a large amount of LPS. The aim of this study was to evaluate the role of this layer in innate immunity. Using the Saika-style rice polishing process, a sbaleurone layer and the rice retaining a subaleurone layer and polished white rice were prepared from brown rice. Using hot-water extracts from rice, LPS content was measured by the Limulus reaction and the effect of activation of macrophages was evaluated on the basis of their phagocytic activity and nitric monoxide (NO) and tumor necrosis factor (TNF) production levels. Toll-like receptor (TLR)-2-, TLR-4- and TLR-9-transfected human embryonic kidney (HEK) cells were used to identify the activation pathway. An allergy mouse model was used to evaluate the prevention of pollen allergy. When compared to polished white rice, rice retaining a subaleurone layer had a 6-fold increase in LPS and an increased macrophage activation when phagocytic activity and NO and TNF production were used as indices. TRL4 was the major pathway for such activation. Anti-allergy test by oral intake of subaleurone showed a significant preventive effect for pollen allergy. Compared to polished white rice, rice retaining a subaleurone layer contained a high level of LPS with higher macrophage activation. Furthermore, oral administration of the rice demonstrated a preventive effect for pollen allergy, thus indicating its utility as a functional food that has a regulatory effect on innate immunity. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

The alveolar macrophage.

PubMed

Bowden, D H

1984-04-01

The pulmonary macrophagic system is critical to the defense of the lung, keeping the alveoli clean and sterile and responding on demand with an adaptive outpouring of new cells into the air sacs. Under basal conditions alveolar macrophages, in common with other mononuclear phagocytes, are derived from the bone marrow. A population of macrophage precursors within the pulmonary interstitium provides a reserve pool capable of proliferation and delivery of phagocytes in response to unusually heavy loads of inhaled particles. This reserve system also produces macrophages when monocytic precursors in the bone marrow are depleted by diseases such as leukemia. The alveolar macrophage is destined to ingest particulate matter and to be eliminated along the mucociliary pathway; clearance by lymphatics is of minor importance and macrophages probably do not recross the alveolar epithelium to reach the pulmonary interstitial compartment. Although the protective role of the macrophage is dominant, this cell may participate, directly or indirectly, in the genesis of two major groups of chronic pulmonary disease, interstitial fibrosis and emphysema. Such inappropriate responses involve interactions with fibroblastic cells and tissue injury initiated by proteases secreted by the macrophage.

Heparanase and macrophage interplay in the onset of liver fibrosis.

PubMed

Secchi, Maria Francesca; Crescenzi, Marika; Masola, Valentina; Russo, Francesco Paolo; Floreani, Annarosa; Onisto, Maurizio

2017-11-02

The heparan sulfate endoglycosidase heparanase (HPSE) is involved in tumor growth, chronic inflammation and fibrosis. Since a role for HPSE in chronic liver disease has not been demonstrated to date, the current study was aimed at investigating the involvement of HPSE in the pathogenesis of chronic liver injury. Herein, we revealed that HPSE expression increased in mouse livers after carbon tetrachloride (CCl 4 )-mediated chronic induction of fibrosis, but with a trend to decline during progression of the disease. In mouse fibrotic liver tissues HPSE immunostaining was restricted in necro-inflammatory areas, co-localizing with F4/80 macrophage marker and TNF-α. TNF-α treatment induced HPSE expression as well as HPSE secretion in U937 macrophages. Moreover, macrophage-secreted HPSE regulated the expression of α-SMA and fibronectin in hepatic stellate LX-2 cells. Finally, HPSE activity increased in the plasma of patients with liver fibrosis but it inversely correlated with liver stiffness. Our results suggest the involvement of HPSE in early phases of reaction to liver damage and inflammatory macrophages as an important source of HPSE. HPSE seems to play a key role in the macrophage-mediated activation of hepatic stellate cells (HSCs), thus suggesting that HPSE targeting could be a new therapeutic option in the treatment of liver fibrosis.

Albumin/asparaginase capsules prepared by ultrasound to retain ammonia.

PubMed

Tinoco, Ana; Ribeiro, Artur; Oliveira, César; Parpot, Pier; Gomes, Andreia; Cavaco-Paulo, Artur

2016-11-01

Asparaginase reduces the levels of asparagine in blood, which is an essential amino acid for the proliferation of lymphoblastic malign cells. Asparaginase converts asparagine into aspartic acid and ammonia. The accumulation of ammonia in the bloodstream leads to hyperammonemia, described as one of the most significant side effects of asparaginase therapy. Therefore, there is a need for asparaginase formulations with the potential to reduce hyperammonemia. We incorporated 2 % of therapeutic enzyme in albumin-based capsules. The presence of asparaginase in the interface of bovine serum albumin (BSA) capsules showed the ability to hydrolyze the asparagine and retain the forming ammonia at the surface of the capsules. The incorporation of Poloxamer 407 in the capsule formulation further increased the ratio aspartic acid/ammonia from 1.92 to 2.46 (and 1.10 from the free enzyme), decreasing the levels of free ammonia. This capacity to retain ammonia can be due to electrostatic interactions and retention of ammonia at the surface of the capsules. The developed BSA/asparaginase capsules did not cause significant cytotoxic effect on mouse leukemic macrophage cell line RAW 264.7. The new BSA/asparaginase capsules could potentially be used in the treatment of acute lymphoblastic leukemia preventing hyperammonemia associated with acute lymphoblastic leukemia (ALL) treatment with asparaginase.

Long Noncoding RNA Profiling from Fasciola Gigantica Excretory/Secretory Product-Induced M2 to M1 Macrophage Polarization.

PubMed

Luo, Honglin; Zhang, Yaoyao; Sheng, Zhaoan; Luo, Tao; Chen, Jie; Liu, Junjie; Wang, Huifeng; Chen, Miao; Shi, Yunliang; Li, Lequn

2018-05-22

Long noncoding RNAs (lncRNAs) are well known regulators of gene expression that play essential roles in macrophage activation and polarization. However, the role of lncRNA in Fasciola gigantica excretory/secretory products (ESP)-induced M2 polarization into M1 macrophages is unclear. Herein, we performed lncRNA profiling of lncRNAs and mRNAs during the ESP-induced macrophage polarization process. F. gigantica ESP was used to induce peritoneal cavity M2 macrophages in BALB/c mice (5-6 weeks old) in vivo, and these cells were subsequently isolated and stimulated with IFN-γ + LPS to induce M1 cells in vitro. LncRNA and mRNA profiling was performed via microarray at the end of both polarization stages. In total, 2,844 lncRNAs (1,579 upregulated and 1,265 downregulated) and 1,782 mRNAs (789 upregulated and 993 downregulated) were differentially expressed in M2 macrophages compared to M1 macrophages, and six lncRNAs were identified during polarization. We selected 34 differentially expressed lncRNAs and mRNAs to validate the results of microarray analysis using quantitative real-time PCR (qPCR). Pathway and Gene Ontology (GO) analyses demonstrated that these altered transcripts were involved in multiple biological processes, particularly peptidase activity and carbohydrate metabolism. Furthermore, coding and non-coding gene (CNC) and mRNA-related ceRNA network analyses were conducted to predict lncRNA expression trends and the potential target genes of these lncRNAs and mRNAs. Moreover, we determined that four lncRNAs and four mRNAs might participate in F. gigantica ESP-induced M2 polarization into M1 macrophages. This study illustrates the basic profiling of lncRNAs and mRNAs during F. gigantica ESP-induced M2 polarization into M1 macrophages and deepens our understanding of the mechanism underlying this process. © 2018 The Author(s). Published by S. Karger AG, Basel.

Heterogeneity of macrophages in injured trigeminal nerves: cytokine/chemokine expressing vs. phagocytic macrophages.

PubMed

Lee, SeungHwan; Zhang, Ji

2012-08-01

Macrophages are important immune effector cells in both innate and adaptive immune responses. Injury to peripheral nerves triggers activation of resident macrophages and infiltration of haematogenous macrophages, which they play critical roles in Wallerian degeneration and neuropathic pain. As macrophages are able to change their phenotypes in response to environment cues, we attempt to identify distinct phenotypes of macrophages in injured nerves and to understand the potential contribution of each macrophage subpopulation to the genesis of neuropathic pain associated with nerve injury. Rat mental nerves (terminal branches of trigeminal nerve) were loosely ligated. Sensitivity to mechanical stimuli at the lower lip area was monitored using calibrated von Frey Hairs. We examined the expression pattern of Iba-1, MAC1 and ED1 which allow us to reveal the immunophenotypes of macrophages at different time points post-injury. Functional status of each macrophage subpopulation was further investigated by colocalization with cytokines/chemokines, myelin basic protein and MHC II antigen, which reflect respectively secretory, phagocytic and antigen presentation properties of activated macrophages. Following nerve injury, a burst of Iba-1(+) macrophages was found in injured mental nerves. Among them, we detected two major immunophenotypes: MAC1(+) cytokines/chemokines secreting macrophages and ED1(+) phagocytic macrophages. Small, round shaped MAC1(+) macrophages were distributed essentially around the lesion site and existed only at early time points. Large, irregular and foamy ED1(+) macrophages were found among damaged nerve fibers and they persisted for at least 3 months post-injury. Although ED1(+) macrophages did not secrete inflammatory mediators, they were able to express neurotransmitter CGRP and MHC II at later time points. In parallel, we observed that mechanical allodynia developed after the nerve ligation was at its lowest level within 1 month. Although slightly

Glutamate metabolism in HIV-1 infected macrophages: Role of HIV-1 Vpr.

PubMed

Datta, Prasun K; Deshmane, Satish; Khalili, Kamel; Merali, Salim; Gordon, John C; Fecchio, Chiara; Barrero, Carlos A

2016-09-01

HIV-1 infected macrophages play a significant role in the neuropathogenesis of AIDS. HIV-1 viral protein R (Vpr) not only facilitates HIV-1 infection but also contribute to long-lived persistence in macrophages. Our previous studies using SILAC-based proteomic analysis showed that the expression of critical metabolic enzymes in the glycolytic pathway and tricarboxylic acid (TCA) cycle were altered in response to Vpr expression in macrophages. We hypothesized that Vpr-induced modulation of glycolysis and TCA cycle regulates glutamate metabolism and release in HIV-1 infected macrophages. We assessed the amount of specific metabolites induced by Vpr and HIV-1 in macrophages at the intracellular and extracellular level in a time-dependent manner utilizing multiple reaction monitoring (MRM) targeted metabolomics. In addition, stable isotope-labeled glucose and an MRM targeted metabolomics assay were used to evaluate the de novo synthesis and release of glutamate in Vpr overexpressing macrophages and HIV-1 infected macrophages, throughout the metabolic flux of glycolytic pathway and TCA cycle activation. The metabolic flux studies demonstrated an increase in glucose uptake, glutamate release and accumulation of α-ketoglutarate (α-KG) and glutamine in the extracellular milieu in Vpr expressing and HIV-1 infected macrophages. Interestingly, glutamate pools and other intracellular intermediates (glucose-6-phosphate (G6P), fructose-6-phosphate (F6P), citrate, malate, α-KG, and glutamine) showed a decreased trend except for fumarate, in contrast to the glutamine accumulation observed in the extracellular space in Vpr overexpressing macrophages. Our studies demonstrate that dysregulation of mitochondrial glutamate metabolism induced by Vpr in HIV-1 infected macrophages commonly seen, may contribute to neurodegeneration via excitotoxic mechanisms in the context of NeuroAIDS.

Stimulatory Effects of Polysaccharide Fraction from Solanum nigrum on RAW 264.7 Murine Macrophage Cells

PubMed Central

Razali, Faizan Naeem; Ismail, Amirah; Abidin, Nurhayati Zainal; Shuib, Adawiyah Suriza

2014-01-01

The polysaccharide fraction from Solanum nigrum Linne has been shown to have antitumor activity by enhancing the CD4+/CD8+ ratio of the T-lymphocyte subpopulation. In this study, we analyzed a polysaccharide extract of S. nigrum to determine its modulating effects on RAW 264.7 murine macrophage cells since macrophages play a key role in inducing both innate and adaptive immune responses. Crude polysaccharide was extracted from the stem of S. nigrum and subjected to ion-exchange chromatography to partially purify the extract. Five polysaccharide fractions were then subjected to a cytotoxicity assay and a nitric oxide production assay. To further analyze the ability of the fractionated polysaccharide extract to activate macrophages, the phagocytosis activity and cytokine production were also measured. The polysaccharide fractions were not cytotoxic, but all of the fractions induced nitric oxide in RAW 264.7 cells. Of the five fractions tested, SN-ppF3 was the least toxic and also induced the greatest amount of nitric oxide, which was comparable to the inducible nitric oxide synthase expression detected in the cell lysate. This fraction also significantly induced phagocytosis activity and stimulated the production of tumor necrosis factor-α and interleukin-6. Our study showed that fraction SN-ppF3 could classically activate macrophages. Macrophage induction may be the manner in which polysaccharides from S. nigrum are able to prevent tumor growth. PMID:25299340

Fibronectin induces macrophage migration through a SFK-FAK/CSF-1R pathway.

PubMed

Digiacomo, Graziana; Tusa, Ignazia; Bacci, Marina; Cipolleschi, Maria Grazia; Dello Sbarba, Persio; Rovida, Elisabetta

2017-07-04

Integrins, following binding to proteins of the extracellular matrix (ECM) including collagen, laminin and fibronectin (FN), are able to transduce molecular signals inside the cells and to regulate several biological functions such as migration, proliferation and differentiation. Besides activation of adaptor molecules and kinases, integrins transactivate Receptor Tyrosine Kinases (RTK). In particular, adhesion to the ECM may promote RTK activation in the absence of growth factors. The Colony-Stimulating Factor-1 Receptor (CSF-1R) is a RTK that supports the survival, proliferation, and motility of monocytes/macrophages, which are essential components of innate immunity and cancer development. Macrophage interaction with FN is recognized as an important aspect of host defense and wound repair. The aim of the present study was to investigate on a possible cross-talk between FN-elicited signals and CSF-1R in macrophages. FN induced migration in BAC1.2F5 and J774 murine macrophage cell lines and in human primary macrophages. Adhesion to FN determined phosphorylation of the Focal Adhesion Kinase (FAK) and Src Family Kinases (SFK) and activation of the SFK/FAK complex, as witnessed by paxillin phosphorylation. SFK activity was necessary for FAK activation and macrophage migration. Moreover, FN-induced migration was dependent on FAK in either murine macrophage cell lines or human primary macrophages. FN also induced FAK-dependent/ligand-independent CSF-1R phosphorylation, as well as the interaction between CSF-1R and β1. CSF-1R activity was necessary for FN-induced macrophage migration. Indeed, genetic or pharmacological inhibition of CSF-1R prevented FN-induced macrophage migration. Our results identified a new SFK-FAK/CSF-1R signaling pathway that mediates FN-induced migration of macrophages.

Peculiar macrophagous adaptations in a new Cretaceous pliosaurid

PubMed Central

Arkhangelsky, Maxim S.; Stenshin, Ilya M.; Uspensky, Gleb N.; Zverkov, Nikolay G.

2015-01-01

During the Middle and Late Jurassic, pliosaurid plesiosaurs evolved gigantic body size and a series of craniodental adaptations that have been linked to the occupation of an apex predator niche. Cretaceous pliosaurids (i.e. Brachaucheninae) depart from this morphology, being slightly smaller and lacking the macrophagous adaptations seen in earlier forms. However, the fossil record of Early Cretaceous pliosaurids is poor, concealing the evolution and ecological diversity of the group. Here, we report a new pliosaurid from the Late Hauterivian (Early Cretaceous) of Russia. Phylogenetic analyses using reduced consensus methods recover it as the basalmost brachauchenine. This pliosaurid is smaller than other derived pliosaurids, has tooth alveoli clustered in pairs and possesses trihedral teeth with complex serrated carinae. Maximum-likelihood ancestral state reconstruction suggests early brachauchenines retained trihedral teeth from their ancestors, but modified this feature in a unique way, convergent with macrophagous archosaurs or sphenacodontoids. Our findings indicate that Early Cretaceous marine reptile teeth with serrated carinae cannot be unequivocally assigned to metriorhynchoid crocodylomorphs. Furthermore, they extend the known diversity of dental adaptations seen in Sauropterygia, the longest lived clade of marine tetrapods. PMID:27019740

Dexamethasone targeted directly to macrophages induces macrophage niches that promote erythroid expansion.

PubMed

Falchi, Mario; Varricchio, Lilian; Martelli, Fabrizio; Masiello, Francesca; Federici, Giulia; Zingariello, Maria; Girelli, Gabriella; Whitsett, Carolyn; Petricoin, Emanuel F; Moestrup, Søren Kragh; Zeuner, Ann; Migliaccio, Anna Rita

2015-02-01

Cultures of human CD34(pos) cells stimulated with erythroid growth factors plus dexamethasone, a model for stress erythropoiesis, generate numerous erythroid cells plus a few macrophages (approx. 3%; 3:1 positive and negative for CD169). Interactions occurring between erythroblasts and macrophages in these cultures and the biological effects associated with these interactions were documented by live phase-contrast videomicroscopy. Macrophages expressed high motility interacting with hundreds/thousands of erythroblasts per hour. CD169(pos) macrophages established multiple rapid 'loose' interactions with proerythroblasts leading to formation of transient erythroblastic island-like structures. By contrast, CD169(neg) macrophages established 'tight' interactions with mature erythroblasts and phagocytosed these cells. 'Loose' interactions of CD169(pos) macrophages were associated with proerythroblast cytokinesis (the M phase of the cell cycle) suggesting that these interactions may promote proerythroblast duplication. This hypothesis was tested by experiments that showed that as few as 103 macrophages significantly increased levels of 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide incorporation frequency in S/G2/M and cytokinesis expressed by proerythroblasts over 24 h of culture. These effects were observed also when macrophages were co-cultured with dexamethasone directly conjugated to a macrophage-specific CD163 antibody. In conclusion, in addition to promoting proerythroblast proliferation directly, dexamethasone stimulates expansion of these cells indirectly by stimulating maturation and cytokinesis supporting activity of macrophages. Copyright© Ferrata Storti Foundation.

Inhibition of melanin synthesis pathway by tricyclazole increases susceptibility of Fonsecaea pedrosoi against mouse macrophages.

PubMed

Cunha, Marcel M L; Franzen, Anderson J; Alviano, Daniela S; Zanardi, Erica; Alviano, Celuta S; De Souza, Wanderley; Rozental, Sonia

2005-12-15

Fonsecaea pedrosoi produces melanin, a pigment related to virulence in pathogenic fungi. To understand the involvement of melanin in the protection of fungi, the authors used tricyclazole to inhibit the melanin pathway in F. pedrosoi. Experiments of pigmentation suggested that F. pedrosoi uniquely produces dihydroxynaphthalene-melanin. Pigments produced on cultures modified or not with tricyclazole were extracted by an alkali-acid method and submitted to infrared and ion exchange chromatography analysis; also cytochemistry analysis for cationized ferritin of whole cells was carried out. This group of experiments showed that the tricyclazole treatment on F. pedrosoi produced a melanin-like pigment, but less negatively charged and with less affinity for iron ions than that without the tricyclazole treatment, and this in turn lead to a less negatively charge cell wall surface. Scanning electron microscopy of such pigments showed that the melanin from control cultures maintained their hyphae-like structures, which have been described as "melanin-ghosts," whereas the tricyclazole pigment showed an amorphous surface. Interaction of conidia from cultures of F. pedrosoi, modified by tricyclazole or not, with peritoneal activated macrophages suggested that tricyclazole causes higher association of fungus with macrophages, weakens the fungus capacity to destroy the macrophages, and diminishes the resistance to dry fracture procedures on samples prepared for high resolution scanning electron microscopy. Copyright (c) 2005 Wiley-Liss, Inc.

Purinergic signaling during macrophage differentiation results in M2 alternative activated macrophages.

PubMed

Barberà-Cremades, Maria; Baroja-Mazo, Alberto; Pelegrín, Pablo

2016-02-01

Macrophages represent a highly heterogenic cell population of the innate immune system, with important roles in the initiation and resolution of the inflammatory response. Purinergic signaling regulates both M1 and M2 macrophage function at different levels by controlling the secretion of cytokines, phagocytosis, and the production of reactive oxygen species. We found that extracellular nucleotides arrest macrophage differentiation from bone marrow precursors via adenosine and P2 receptors. This results in a mature macrophage with increased expression of M2, but not M1, genes. Similar to adenosine and ATP, macrophage growth arrested with LPS treatment resulted in an increase of the M2-related marker Ym1. Recombinant Ym1 was able to affect macrophage proliferation and could, potentially, be involved in the arrest of macrophage growth during hematopoiesis. © Society for Leukocyte Biology.

Conservative management of placenta accreta: hysteroscopic resection of retained tissues.

PubMed

Legendre, Guillaume; Zoulovits, Félicia Joinau; Kinn, Juliette; Senthiles, Loïc; Fernandez, Hervé

2014-01-01

To evaluate the feasibility and the results of hysteroscopic removal of tissue after conservative management of retained placenta accreta. Retrospective study (Canadian Task Force classification II-3). Tertiary care university hospital. Twelve consecutive patients with hysteroscopic resection of retained tissues after conservative management of placenta accreta. Hysteroscopic removal of retained placenta tissue using a 24F bipolar resectoscope. Twelve patients with retained placenta tissue, complete in 2 and partial in 10, were included. Mean retained placenta size on magnetic resonance imaging was 54 mm (range, 13-110 mm). Complete removal was achieved in all but 1 patient who underwent a secondary hysterectomy after the first incomplete hysteroscopic resection. Complete evacuation of the uterus was completed after 1 procedure in 5 patients, after 2 procedures in 2 patients, and after 3 procedures in 4 patients. All but 2 patients had normal menstrual bleeding after hysteroscopy. Four pregnancies occurred in our series, resulting in 1 ectopic pregnancy, 1 miscarriage, and 2 deliveries. Hysteroscopic resection of retained placenta seems to be a safe and effective procedure to prevent major complications and to preserve fertility in cases of conservative management of placenta accreta. Copyright © 2014 AAGL. Published by Elsevier Inc. All rights reserved.

Biodegradation of carbon nanohorns in macrophage cells

NASA Astrophysics Data System (ADS)

Zhang, Minfang; Yang, Mei; Bussy, Cyrill; Iijima, Sumio; Kostarelos, Kostas; Yudasaka, Masako

2015-02-01

With the rapid developments in the medical applications of carbon nanomaterials such as carbon nanohorns (CNHs), carbon nanotubes, and graphene based nanomaterials, understanding the long-term fate, health impact, excretion, and degradation of these materials has become crucial. Herein, the in vitro biodegradation of CNHs was determined using a non-cellular enzymatic oxidation method and two types of macrophage cell lines. Approximately 60% of the CNHs was degraded within 24 h in a phosphate buffer solution containing myeloperoxidase. Furthermore, approximately 30% of the CNHs was degraded by both RAW 264.7 and THP-1 macrophage cells within 9 days. Inflammation markers such as pro-inflammatory cytokines interleukin 6 and tumor necrosis factor α were not induced by exposure to CNHs. However, reactive oxygen species were generated by the macrophage cells after uptake of CNHs, suggesting that these species were actively involved in the degradation of the nanomaterials rather than in an inflammatory pathway induction.With the rapid developments in the medical applications of carbon nanomaterials such as carbon nanohorns (CNHs), carbon nanotubes, and graphene based nanomaterials, understanding the long-term fate, health impact, excretion, and degradation of these materials has become crucial. Herein, the in vitro biodegradation of CNHs was determined using a non-cellular enzymatic oxidation method and two types of macrophage cell lines. Approximately 60% of the CNHs was degraded within 24 h in a phosphate buffer solution containing myeloperoxidase. Furthermore, approximately 30% of the CNHs was degraded by both RAW 264.7 and THP-1 macrophage cells within 9 days. Inflammation markers such as pro-inflammatory cytokines interleukin 6 and tumor necrosis factor α were not induced by exposure to CNHs. However, reactive oxygen species were generated by the macrophage cells after uptake of CNHs, suggesting that these species were actively involved in the degradation of the

Enhancement of phagocytosis and cytotoxicity in macrophages by tumor-derived IL-18 stimulation

PubMed Central

Henan, Xu; Toyota, Naoka; Yanjiang, Xing; Fujita, Yuuki; Zhijun, Huang; Touma, Maki; Qiong, Wu; Sugimoto, Kenkichi

2014-01-01

Inoculation of mice with the murine NFSA cell line caused the formation of large tumors with necrotic tumor cores. FACS analysis revealed accumulations of CD11b+ cells in the tumors. Microarray analysis indicated that the NFSA cells expressed a high level of the pro-inflammatory factor interleukin-18 (il-18), which is known to play a critical role in macrophages. However, little is known about the physiological function of IL-18-stimulated macrophages. Here, we provide direct evidence that IL-18 enhances the phagocytosis of RAW264 cells and peritoneal macrophages, accompanied by the increased expression of tumor necrosis factor (tnf-α), interleukin-6 (il-6) and inducible nitric oxide synthase (Nos2). IL-18-stimulated RAW264 cells showed an enhanced cytotoxicity to endothelial F-2 cells via direct cell-to-cell interaction and the secretion of soluble mediators. Taken together, our results demonstrate that tumor-derived IL-18 plays an important role in the phagocytosis of macrophages and that IL-18-stimulated macrophages may damage tumor endothelial cells. [BMB Reports 2014; 47(5): 286-291] PMID:24286318

Glutamate metabolism in HIV-1 infected macrophages: Role of HIV-1 Vpr

PubMed Central

Datta, Prasun K.; Deshmane, Satish; Khalili, Kamel; Merali, Salim; Gordon, John C.; Fecchio, Chiara; Barrero, Carlos A.

2016-01-01

ABSTRACT HIV-1 infected macrophages play a significant role in the neuropathogenesis of AIDS. HIV-1 viral protein R (Vpr) not only facilitates HIV-1 infection but also contribute to long-lived persistence in macrophages. Our previous studies using SILAC-based proteomic analysis showed that the expression of critical metabolic enzymes in the glycolytic pathway and tricarboxylic acid (TCA) cycle were altered in response to Vpr expression in macrophages. We hypothesized that Vpr-induced modulation of glycolysis and TCA cycle regulates glutamate metabolism and release in HIV-1 infected macrophages. We assessed the amount of specific metabolites induced by Vpr and HIV-1 in macrophages at the intracellular and extracellular level in a time-dependent manner utilizing multiple reaction monitoring (MRM) targeted metabolomics. In addition, stable isotope-labeled glucose and an MRM targeted metabolomics assay were used to evaluate the de novo synthesis and release of glutamate in Vpr overexpressing macrophages and HIV-1 infected macrophages, throughout the metabolic flux of glycolytic pathway and TCA cycle activation. The metabolic flux studies demonstrated an increase in glucose uptake, glutamate release and accumulation of α-ketoglutarate (α-KG) and glutamine in the extracellular milieu in Vpr expressing and HIV-1 infected macrophages. Interestingly, glutamate pools and other intracellular intermediates (glucose-6-phosphate (G6P), fructose-6-phosphate (F6P), citrate, malate, α-KG, and glutamine) showed a decreased trend except for fumarate, in contrast to the glutamine accumulation observed in the extracellular space in Vpr overexpressing macrophages. Our studies demonstrate that dysregulation of mitochondrial glutamate metabolism induced by Vpr in HIV-1 infected macrophages commonly seen, may contribute to neurodegeneration via excitotoxic mechanisms in the context of NeuroAIDS. PMID:27245560

Renal F4/80+ CD11c+ mononuclear phagocytes display phenotypic and functional characteristics of macrophages in health and in adriamycin nephropathy.

PubMed

Cao, Qi; Wang, Yiping; Wang, Xin Maggie; Lu, Junyu; Lee, Vincent W S; Ye, Qianling; Nguyen, Hanh; Zheng, Guoping; Zhao, Ye; Alexander, Stephen I; Harris, David C H

2015-02-01

Conventional markers of macrophages (Mфs) and dendritic cells (DCs) lack specificity and often overlap, leading to confusion and controversy regarding the precise function of these cells in kidney and other diseases. This study aimed to identify the phenotype and function of renal mononuclear phagocytes (rMPs) expressing key markers of both Mфs and DCs. F4/80(+)CD11c(+) cells accounted for 45% of total rMPs in normal kidneys and in those from mice with Adriamycin nephropathy (AN). Despite expression of the DC marker CD11c, these double-positive rMPs displayed the features of Mфs, including Mф-like morphology, high expression of CD68, CD204, and CD206, and high phagocytic ability but low antigen-presenting ability. F4/80(+)CD11c(+) cells were found in the cortex but not in the medulla of the kidney. In AN, F4/80(+)CD11c(+) cells displayed an M1 Mф phenotype with high expression of inflammatory mediators and costimulatory factors. Adoptive transfer of F4/80(+)CD11c(+) cells separated from diseased kidney aggravated renal injury in AN mice. Furthermore, adoptive transfer of common progenitors revealed that kidney F4/80(+)CD11c(+) cells were derived predominantly from monocytes, but not from pre-DCs. In conclusion, renal F4/80(+)CD11c(+) cells are a major subset of rMPs and display Mф-like phenotypic and functional characteristics in health and in AN. Copyright © 2015 by the American Society of Nephrology.

LL-37 directs macrophage differentiation toward macrophages with a proinflammatory signature.

PubMed

van der Does, Anne M; Beekhuizen, Henry; Ravensbergen, Bep; Vos, Tim; Ottenhoff, Tom H M; van Dissel, Jaap T; Drijfhout, Jan W; Hiemstra, Pieter S; Nibbering, Peter H

2010-08-01

The human cathelicidin LL-37 has broad-spectrum antimicrobial activity. It also participates at the interface of innate and adaptive immunity by chemoattracting immune effector cells, modulating the production of a variety of inflammatory mediators by different cell types, and regulating the differentiation of monocytes into dendritic cells. In this study, we investigated the effects of LL-37 on the differentiation of human monocytes into anti-inflammatory macrophages (MPhi-2; driven by M-CSF) versus proinflammatory macrophages (MPhi-1; driven by GM-CSF) as well as on fully differentiated MPhi-1 and MPhi-2. Results revealed that monocytes cultured with M-CSF in the presence of LL-37 resulted in macrophages displaying a proinflammatory signature, namely, low expression of CD163 and little IL-10 and profound IL-12p40 production on LPS stimulation. The effects of LL-37 on M-CSF-driven macrophage differentiation were dose- and time-dependent with maximal effects observed at 10 microg/ml when the peptide was present from the start of the cultures. The peptide enhanced the GM-CSF-driven macrophage differentiation. Exposure of fully differentiated MPhi-2 to LL-37 for 6 d resulted in macrophages that produced less IL-10 and more IL-12p40 on LPS stimulation than control MPhi-2. In contrast, LL-37 had no effect on fully differentiated MPhi-1. Peptide mapping using a set of 16 overlapping 22-mer peptides covering the complete LL-37 sequence revealed that the C-terminal portion of LL-37 is responsible for directing macrophage differentiation. Our results furthermore indicate that the effects of LL-37 on macrophage differentiation required internalization of the peptide. Together, we conclude that LL-37 directs macrophage differentiation toward macrophages with a proinflammatory signature.

Macrophages under pressure: the role of macrophage polarization in hypertension.

PubMed

Harwani, Sailesh C

2018-01-01

Hypertension is a multifactorial disease involving the nervous, renal, and cardiovascular systems. Macrophages are the most abundant and ubiquitous immune cells, placing them in a unique position to serve as key mediators between these components. The polarization of macrophages confers vast phenotypic and functional plasticity, allowing them to act as proinflammatory, homeostatic, and anti-inflammatory agents. Key differences between the M1 and M2 phenotypes, the 2 subsets at the extremes of this polarization spectrum, place macrophages at a juncture to mediate many mechanisms involved in the pathogenesis of hypertension. Neuronal and non-neuronal regulation of the immune system, that is, the "neuroimmuno" axis, plays an integral role in the polarization of macrophages. In hypertension, the neuroimmuno axis results in synchronization of macrophage mobilization from immune cell reservoirs and their chemotaxis, via increased expression of chemoattractants, to end organs critical in the development of hypertension. This complicated system is largely coordinated by the dichotomous actions of the autonomic neuronal and non-neuronal activation of cholinergic, adrenergic, and neurohormonal receptors on macrophages, leading to their ability to "switch" between phenotypes at sites of active inflammation. Data from experimental models and human studies are in concordance with each other and support a central role for macrophage polarization in the pathogenesis of hypertension. Copyright © 2017 Elsevier Inc. All rights reserved.

Human CD68 promoter GFP transgenic mice allow analysis of monocyte to macrophage differentiation in vivo

PubMed Central

Iqbal, Asif J.; McNeill, Eileen; Kapellos, Theodore S.; Regan-Komito, Daniel; Norman, Sophie; Burd, Sarah; Smart, Nicola; Machemer, Daniel E. W.; Stylianou, Elena; McShane, Helen; Channon, Keith M.; Chawla, Ajay

2014-01-01

The recruitment of monocytes and their differentiation into macrophages at sites of inflammation are key events in determining the outcome of the inflammatory response and initiating the return to tissue homeostasis. To study monocyte trafficking and macrophage differentiation in vivo, we have generated a novel transgenic reporter mouse expressing a green fluorescent protein (GFP) under the control of the human CD68 promoter. CD68-GFP mice express high levels of GFP in both monocyte and embryo-derived tissue resident macrophages in adult animals. The human CD68 promoter drives GFP expression in all CD115+ monocytes of adult blood, spleen, and bone marrow; we took advantage of this to directly compare the trafficking of bone marrow–derived CD68-GFP monocytes to that of CX3CR1GFP monocytes in vivo using a sterile zymosan peritonitis model. Unlike CX3CR1GFP monocytes, which downregulate GFP expression on differentiation into macrophages in this model, CD68-GFP monocytes retain high-level GFP expression for 72 hours after differentiation into macrophages, allowing continued cell tracking during resolution of inflammation. In summary, this novel CD68-GFP transgenic reporter mouse line represents a powerful resource for analyzing monocyte mobilization and monocyte trafficking as well as studying the fate of recruited monocytes in models of acute and chronic inflammation. PMID:25030063

Human CD68 promoter GFP transgenic mice allow analysis of monocyte to macrophage differentiation in vivo.

PubMed

Iqbal, Asif J; McNeill, Eileen; Kapellos, Theodore S; Regan-Komito, Daniel; Norman, Sophie; Burd, Sarah; Smart, Nicola; Machemer, Daniel E W; Stylianou, Elena; McShane, Helen; Channon, Keith M; Chawla, Ajay; Greaves, David R

2014-10-09

The recruitment of monocytes and their differentiation into macrophages at sites of inflammation are key events in determining the outcome of the inflammatory response and initiating the return to tissue homeostasis. To study monocyte trafficking and macrophage differentiation in vivo, we have generated a novel transgenic reporter mouse expressing a green fluorescent protein (GFP) under the control of the human CD68 promoter. CD68-GFP mice express high levels of GFP in both monocyte and embryo-derived tissue resident macrophages in adult animals. The human CD68 promoter drives GFP expression in all CD115(+) monocytes of adult blood, spleen, and bone marrow; we took advantage of this to directly compare the trafficking of bone marrow-derived CD68-GFP monocytes to that of CX3CR1(GFP) monocytes in vivo using a sterile zymosan peritonitis model. Unlike CX3CR1(GFP) monocytes, which downregulate GFP expression on differentiation into macrophages in this model, CD68-GFP monocytes retain high-level GFP expression for 72 hours after differentiation into macrophages, allowing continued cell tracking during resolution of inflammation. In summary, this novel CD68-GFP transgenic reporter mouse line represents a powerful resource for analyzing monocyte mobilization and monocyte trafficking as well as studying the fate of recruited monocytes in models of acute and chronic inflammation. © 2014 by The American Society of Hematology.

Dexamethasone palmitate ameliorates macrophages-rich graft-versus-host disease by inhibiting macrophage functions.

PubMed

Nishiwaki, Satoshi; Nakayama, Takayuki; Murata, Makoto; Nishida, Tetsuya; Terakura, Seitaro; Saito, Shigeki; Kato, Tomonori; Mizuno, Hiroki; Imahashi, Nobuhiko; Seto, Aika; Ozawa, Yukiyasu; Miyamura, Koichi; Ito, Masafumi; Takeshita, Kyosuke; Kato, Hidefumi; Toyokuni, Shinya; Nagao, Keisuke; Ueda, Ryuzo; Naoe, Tomoki

2014-01-01

Macrophage infiltration of skin GVHD lesions correlates directly with disease severity, but the mechanisms underlying this relationship remain unclear and GVHD with many macrophages is a therapeutic challenge. Here, we characterize the macrophages involved in GVHD and report that dexamethasone palmitate (DP), a liposteroid, can ameliorate such GVHD by inhibiting macrophage functions. We found that host-derived macrophages could exacerbate GVHD in a mouse model through expression of higher levels of pro-inflammatory TNF-α and IFN-γ, and lower levels of anti-inflammatory IL-10 than resident macrophages in mice without GVHD. DP significantly decreased the viability and migration capacity of primary mouse macrophages compared to conventional dexamethasone in vitro. DP treatment on day 7 and day 14 decreased macrophage number, and attenuated GVHD score and subsequent mortality in a murine model. This is the first study to provide evidence that therapy for GVHD should be changed on the basis of infiltrating cell type.

The response of macrophages to titanium particles is determined by macrophage polarization.

PubMed

Pajarinen, Jukka; Kouri, Vesa-Petteri; Jämsen, Eemeli; Li, Tian-Fang; Mandelin, Jami; Konttinen, Yrjö T

2013-11-01

Aseptic loosening of total joint replacements is driven by the reaction of macrophages to foreign body particles released from the implant. It was hypothesized that the macrophages' response to these particles is dependent, in addition to particle characteristics and contaminating biomolecules, on the state of macrophage polarization as determined by the local cytokine microenvironment. To test this hypothesis we differentiated M1 and M2 macrophages from human peripheral blood monocytes and compared their responses to titanium particles using genome-wide microarray analysis and a multiplex cytokine assay. In comparison to non-activated M0 macrophages, the overall chemotactic and inflammatory responses to titanium particles were greatly enhanced in M1 macrophages and effectively suppressed in M2 macrophages. In addition, the genome-wide approach revealed several novel, potentially osteolytic, particle-induced mediators, and signaling pathway analysis suggested the involvement of toll-like and nod-like receptor signaling in particle recognition. It is concluded that the magnitude of foreign body reaction caused by titanium particles is dependent on the state of macrophage polarization. Thus, by limiting the action of M1 polarizing factors, e.g. bacterial biofilm formation, in peri-implant tissues and promoting M2 macrophage polarization by biomaterial solutions or pharmacologically, it might be possible to restrict wear-particle-induced inflammation and osteolysis. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Candida albicans Chitin Increases Arginase-1 Activity in Human Macrophages, with an Impact on Macrophage Antimicrobial Functions

PubMed Central

MacCallum, Donna M.; Brown, Gordon D.

2017-01-01

ABSTRACT   The opportunistic human fungal pathogen Candida albicans can cause a variety of diseases, ranging from superficial mucosal infections to life-threatening systemic infections. Phagocytic cells of the innate immune response, such as neutrophils and macrophages, are important first-line responders to an infection and generate reactive oxygen and nitrogen species as part of their protective antimicrobial response. During an infection, host cells generate nitric oxide through the enzyme inducible nitric oxide synthase (iNOS) to kill the invading pathogen. Inside the phagocyte, iNOS competes with the enzyme arginase-1 for a common substrate, the amino acid l-arginine. Several pathogenic species, including bacteria and parasitic protozoans, actively modulate the production of nitric oxide by inducing their own arginases or the host’s arginase activity to prevent the conversion of l-arginine to nitric oxide. We report here that C. albicans blocks nitric oxide production in human-monocyte-derived macrophages by induction of host arginase activity. We further determined that purified chitin (a fungal cell wall polysaccharide) and increased chitin exposure at the fungal cell wall surface induces this host arginase activity. Blocking the C. albicans-induced arginase activity with the arginase-specific substrate inhibitor Nω-hydroxy-nor-arginine (nor-NOHA) or the chitinase inhibitor bisdionin F restored nitric oxide production and increased the efficiency of fungal killing. Moreover, we determined that C. albicans influences macrophage polarization from a classically activated phenotype toward an alternatively activated phenotype, thereby reducing antimicrobial functions and mediating fungal survival. Therefore, C. albicans modulates l-arginine metabolism in macrophages during an infection, potentiating its own survival. PMID:28119468

Leucine supplementation attenuates macrophage foam-cell formation: Studies in humans, mice, and cultured macrophages.

PubMed

Grajeda-Iglesias, Claudia; Rom, Oren; Hamoud, Shadi; Volkova, Nina; Hayek, Tony; Abu-Saleh, Niroz; Aviram, Michael

2018-02-05

Whereas atherogenicity of dietary lipids has been largely studied, relatively little is known about the possible contribution of dietary amino acids to macrophage foam-cell formation, a hallmark of early atherogenesis. Recently, we showed that leucine has antiatherogenic properties in the macrophage model system. In this study, an in-depth investigation of the role of leucine in macrophage lipid metabolism was conducted by supplementing humans, mice, or cultured macrophages with leucine. Macrophage incubation with serum obtained from healthy adults supplemented with leucine (5 g/d, 3 weeks) significantly decreased cellular cholesterol mass by inhibiting the rate of cholesterol biosynthesis and increasing cholesterol efflux from macrophages. Similarly, leucine supplementation to C57BL/6 mice (8 weeks) resulted in decreased cholesterol content in their harvested peritoneal macrophages (MPM) in relation with reduced cholesterol biosynthesis rate. Studies in J774A.1 murine macrophages revealed that leucine dose-dependently decreased cellular cholesterol and triglyceride mass. Macrophages treated with leucine (0.2 mM) showed attenuated uptake of very low-density lipoproteins and triglyceride biosynthesis rate, with a concurrent down-regulation of diacylglycerol acyltransferase-1, a key enzyme catalyzing triglyceride biosynthesis in macrophages. Similar effects were observed when macrophages were treated with α-ketoisocaproate, a key leucine metabolite. Finally, both in vivo and in vitro leucine supplementation significantly improved macrophage mitochondrial respiration and ATP production. The above studies, conducted in human, mice, and cultured macrophages, highlight a protective role for leucine attenuating macrophage foam-cell formation by mechanisms related to the metabolism of cholesterol, triglycerides, and energy production. © 2018 BioFactors, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

Macrophage Repolarization with Targeted Alginate Nanoparticles Containing IL-10 Plasmid DNA for the Treatment of Experimental Arthritis

PubMed Central

Jain, Shardool; Tran, Thanh-Huyen; Amiji, Mansoor

2015-01-01

In this study, we have shown for the first time the effectiveness of a non-viral gene transfection strategy to re-polarize macrophages from M1 to M2 functional sub-type for the treatment of rheumatoid arthritis (RA). An anti-inflammatory (IL-10) cytokine encoding plasmid DNA was successfully encapsulated into non-condensing alginate based nanoparticles and the surface of the nano-carriers was modified with tuftsin peptide to achieve active macrophage targeting. Enhanced localization of tuftsin-modified alginate nanoparticles was observed in the inflamed paws of arthritic rats upon intraperitoneal administration. Importantly, targeted nanoparticle treatment was successful in reprogramming macrophage phenotype balance as ~66% of total synovial macrophages from arthritic rats treated with the IL-10 plasmid DNA loaded tuftsin/alginate nanoparticles were in the M2 state compared to ~9% of macrophages in the M2 state from untreated arthritic rats. Treatment significantly reduced systemic and joint tissue pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) expression and prevented the progression of inflammation and joint damage as revealed by magnetic resonance imaging and histology. Treatment enabled animals to retain their mobility throughout the course of study, whereas untreated animals suffered from impaired mobility. Overall, this study demonstrates that targeted alginate nanoparticles loaded with IL-10 plasmid DNA can efficiently re-polarize macrophages from an M1 to an M2 state, offering a novel treatment paradigm for treatment of chronic inflammatory diseases. PMID:26004232

Positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging of macrophages in large vessel vasculitis: Current status and future prospects.

PubMed

Jiemy, William Febry; Heeringa, Peter; Kamps, Jan A A M; van der Laken, Conny J; Slart, Riemer H J A; Brouwer, Elisabeth

2018-05-03

Macrophages are key players in the pathogenesis of large-vessel vasculitis (LVV) and may serve as a target for diagnostic imaging of LVV. The radiotracer, 18 F-FDG has proven to be useful in the diagnosis of giant cell arteritis (GCA), a form of LVV. Although uptake of 18 F-FDG is high in activated macrophages, it is not a specific radiotracer as its uptake is high in any proliferating cell and other activated immune cells resulting in high non-specific background radioactivity especially in aging and atherosclerotic vessels which dramatically lowers the diagnostic accuracy. Evidence also exists that the sensitivity of 18 F-FDG PET drops in patients upon glucocorticoid treatment. Therefore, there is a clinical need for more specific radiotracers in imaging GCA to improve diagnostic accuracy. Numerous clinically established and newly developed macrophage targeted radiotracers for oncological and inflammatory diseases can potentially be utilized for LVV imaging. These tracers are more target specific and therefore may provide lower background radioactivity, higher diagnostic accuracy and the ability to assess treatment effectiveness. However, current knowledge regarding macrophage subsets in LVV lesions is limited. Further understanding regarding macrophage subsets in vasculitis lesion is needed for better selection of tracers and new targets for tracer development. This review summarizes the development of macrophage targeted tracers in the last decade and the potential application of macrophage targeted tracers currently used in other inflammatory diseases in imaging LVV. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Acquisition of high metastatic capacity after in vitro fusion of a nonmetastatic tumor line with a bone marrow-derived macrophage

PubMed Central

1984-01-01

A low metastatic, thioguanine-resistant murine T lymphoma line (EbTGR) was hybridized in vitro, with the help of polyethylene glycol, with syngeneic bone marrow-derived macrophages. Two HAT-resistant hybrid lines (Eb-F1 and Eb-F2) were obtained from independent fusion cultures. A cytogenetic analysis revealed that most of the macrophage chromosomes except No. 12 had segregated or become rearranged 60 d after fusion, a time at which the cell lines had become stabilized in culture. Syngeneic mice inoculated subcutaneously with the tumor macrophage hybrid lines developed, very quickly, visceral metastases and died after less than 2 wk, while those inoculated with the parental line lived for greater than 6 wk and developed only localized, large primary tumors. The metastatic hybridomas expressed a similar tumor antigen as a spontaneous, in vivo derived, high metastatic variant (ESb) of the same tumor. This suggests that ESb cells might have arisen from a spontaneous fusion with a host macrophage. PMID:6491605

Soybean-derived Bowman-Birk Inhibitor (BBI) Inhibits HIV Replication in Macrophages.

PubMed

Ma, Tong-Cui; Zhou, Run-Hong; Wang, Xu; Li, Jie-Liang; Sang, Ming; Zhou, Li; Zhuang, Ke; Hou, Wei; Guo, De-Yin; Ho, Wen-Zhe

2016-10-13

The Bowman-Birk inhibitor (BBI), a soybean-derived protease inhibitor, is known to have anti-inflammatory effect in both in vitro and in vivo systems. Macrophages play a key role in inflammation and immune activation, which is implicated in HIV disease progression. Here, we investigated the effect of BBI on HIV infection of peripheral blood monocyte-derived macrophages. We demonstrated that BBI could potently inhibit HIV replication in macrophages without cytotoxicity. Investigation of the mechanism(s) of BBI action on HIV showed that BBI induced the expression of IFN-β and multiple IFN stimulated genes (ISGs), including Myxovirus resistance protein 2 (Mx2), 2',5'-oligoadenylate synthetase (OAS-1), Virus inhibitory protein (viperin), ISG15 and ISG56. BBI treatment of macrophages also increased the expression of several known HIV restriction factors, including APOBEC3F, APOBEC3G and tetherin. Furthermore, BBI enhanced the phosphorylation of IRF3, a key regulator of IFN-β. The inhibition of IFN-β pathway by the neutralization antibody to type I IFN receptor (Anti-IFNAR) abolished BBI-mediated induction of the anti-HIV factors and inhibition of HIV in macrophages. These findings that BBI could activate IFN-β-mediated signaling pathway, initialize the intracellular innate immunity in macrophages and potently inhibit HIV at multiple steps of viral replication cycle indicate the necessity to further investigate BBI as an alternative and cost-effective anti-HIV natural product.

The internalization of fluorescence-labeled PLA nanoparticles by macrophages.

PubMed

Li, Fengjuan; Zhu, Aiping; Song, Xiaoli; Ji, Lijun; Wang, Juan

2013-09-10

Rhodamine B (RhB)-labeled PLA nanoparticles were prepared through surface grafting copolymerization of glycidyl methacrylate (GMA) onto PLA nanoparticles during the emulsion/evaporation process. RhB firstly interacts with sodium dodecyl sulfate (SDS) through electrostatic interaction to form hydrophobic complex (SDS-RhB). Due to the high-affinity of SDS-RhB with GMA, hydrophilic RhB can be successfully combined into PLA nanoparticles. The internalization of RhB-labeled PLA nanoparticles by macrophages was investigated with fluorescence microscope technology. The effects of the PLA nanoparticle surface nature and size on the internalization were investigated. The results indicate that the PLA particles smaller than 200 nm can avoid the uptake of phagocytosis. The bigger PLA particles (300 nm) with polyethylene glycol (PEG) surface showed less internalization by macrophage compared with those with poly(ethylene oxide-propylene oxide) copolymer (F127) or poly(vinyl alcohol) (PVA) surface. The "stealth" function of PEG on the PLA nanoparticles from internalization of macrophages due to the low protein adsorption is revealed by electrochemical impedance technology. Copyright © 2013 Elsevier B.V. All rights reserved.

Reliability Coupled Sensitivity Based Design Approach for Gravity Retaining Walls

NASA Astrophysics Data System (ADS)

Guha Ray, A.; Baidya, D. K.

2012-09-01

Sensitivity analysis involving different random variables and different potential failure modes of a gravity retaining wall focuses on the fact that high sensitivity of a particular variable on a particular mode of failure does not necessarily imply a remarkable contribution to the overall failure probability. The present paper aims at identifying a probabilistic risk factor ( R f ) for each random variable based on the combined effects of failure probability ( P f ) of each mode of failure of a gravity retaining wall and sensitivity of each of the random variables on these failure modes. P f is calculated by Monte Carlo simulation and sensitivity analysis of each random variable is carried out by F-test analysis. The structure, redesigned by modifying the original random variables with the risk factors, is safe against all the variations of random variables. It is observed that R f for friction angle of backfill soil ( φ 1 ) increases and cohesion of foundation soil ( c 2 ) decreases with an increase of variation of φ 1 , while R f for unit weights ( γ 1 and γ 2 ) for both soil and friction angle of foundation soil ( φ 2 ) remains almost constant for variation of soil properties. The results compared well with some of the existing deterministic and probabilistic methods and found to be cost-effective. It is seen that if variation of φ 1 remains within 5 %, significant reduction in cross-sectional area can be achieved. But if the variation is more than 7-8 %, the structure needs to be modified. Finally design guidelines for different wall dimensions, based on the present approach, are proposed.

[Macrophage activation in atherosclerosis. Message 1: Activation of macrophages normally and in atherosclerotic lesions].

PubMed

Nikiforov, N G; Kornienko, V Y; Karagodin, V P; Orekhov, A N

2015-01-01

Macrophages play important role in initiation and progression of inflammation in atherosclerosis. Plaque macrophages were shown to exhibit a phenotypic range that is intermediate between two extremes, M1 (proinflammatory) and M2 (anti-inflammatory). Indeed, in atherosclerosis, macrophages demonstrate phenotypic plasticity to rapidly adjust to changing microenvironmental conditions. In plaque macrophages demonstrate different phenotypes, and besides macrophage phenotypes could be changed. Phenotypes M1, M2, M4, Mhem, HA-mac, M(Hb) u Mox are described in the article. Ability of macrophages change their phenotype also considered.

Macrophage polarisation: an immunohistochemical approach for identifying M1 and M2 macrophages.

PubMed

Barros, Mário Henrique M; Hauck, Franziska; Dreyer, Johannes H; Kempkes, Bettina; Niedobitek, Gerald

2013-01-01

Macrophage polarization is increasingly recognised as an important pathogenetic factor in inflammatory and neoplastic diseases. Proinflammatory M1 macrophages promote T helper (Th) 1 responses and show tumoricidal activity. M2 macrophages contribute to tissue repair and promote Th2 responses. CD68 and CD163 are used to identify macrophages in tissue sections. However, characterisation of polarised macrophages in situ has remained difficult. Macrophage polarisation is regulated by transcription factors, pSTAT1 and RBP-J for M1, and CMAF for M2. We reasoned that double-labelling immunohistochemistry for the detection of macrophage markers together with transcription factors may be suitable to characterise macrophage polarisation in situ. To test this hypothesis, we have studied conditions associated with Th1- and Th2-predominant immune responses: infectious mononucleosis and Crohn's disease for Th1 and allergic nasal polyps, oxyuriasis, wound healing and foreign body granulomas for predominant Th2 response. In all situations, CD163+ cells usually outnumbered CD68+ cells. Moreover, CD163+ cells, usually considered as M2 macrophages, co-expressing pSTAT1 and RBP-J were found in all conditions examined. The numbers of putative M1 macrophages were higher in Th1- than in Th2-associated diseases, while more M2 macrophages were seen in Th2- than in Th1 related disorders. In most Th1-related diseases, the balance of M1 over M2 cells was shifted towards M1 cells, while the reverse was observed for Th2-related conditions. Hierarchical cluster analysis revealed two distinct clusters: cluster I included Th1 diseases together with cases with high numbers of CD163+pSTAT1+, CD68+pSTAT1+, CD163+RBP-J+ and CD68+RBP-J+ macrophages; cluster II comprised Th2 conditions together with cases displaying high numbers of CD163+CMAF+ and CD68+CMAF+ macrophages. These results suggest that the detection of pSTAT1, RBP-J, and CMAF in the context of CD68 or CD163 expression is a suitable tool for

Targeting the Hemoglobin Scavenger receptor CD163 in Macrophages Highly Increases the Anti-inflammatory Potency of Dexamethasone

PubMed Central

Graversen, Jonas H; Svendsen, Pia; Dagnæs-Hansen, Frederik; Dal, Jakob; Anton, Gabriele; Etzerodt, Anders; Petersen, Mikkel D; Christensen, Peter A; Møller, Holger J; Moestrup, Søren K

2012-01-01

Synthetic glucocorticoids are potent anti-inflammatory drugs but serious side effects such as bone mobilization, muscle mass loss, immunosuppression, and metabolic alterations make glucocorticoid therapy a difficult balance. The therapeutic anti-inflammatory effect of glucocorticoids relies largely on the suppressed release of tumor-necrosis factor-α and other cytokines by macrophages at the sites of inflammation. We have now developed a new biodegradable anti-CD163 antibody-drug conjugate that specifically targets the glucocorticoid, dexamethasone to the hemoglobin scavenger receptor CD163 in macrophages. The conjugate, that in average contains four dexamethasone molecules per antibody, exhibits retained high functional affinity for CD163. In vitro studies in rat macrophages and in vivo studies of Lewis rats showed a strong anti-inflammatory effect of the conjugate measured as reduced lipopolysaccharide-induced secretion of tumor-necrosis factor-α. The in vivo potency of conjugated dexamethasone was about 50-fold that of nonconjugated dexamethasone. In contrast to a strong systemic effect of nonconjugated dexamethasone, the equipotent dose of the conjugate had no such effect, measured as thymus lymphocytes apoptosis, body weight loss, and suppression of endogenous cortisol levels. In conclusion, the study shows antibody-drug conjugates as a future approach in anti-inflammatory macrophage-directed therapy. Furthermore, the data demonstrate CD163 as an excellent macrophage target for anti-inflammatory drug delivery. PMID:22643864

[Macrophages in human semen].

PubMed

Bouvet, Beatriz Reina; Brufman, Adriana Silvia; Paparella, Cecilia Vicenta; Feldman, Rodolfo Nestor; Gatti, Vanda Nora; Solis, Edita Amalia

2003-11-01

To investigate the presence of macrophages in human semen samples and the function they carry out in the seminal fluid. Their presence was studied in relation to spermatic morphology, percentage of spermatozoids with native DNA, and presence of antispermatic antibodies. The work was performed with semen samples from 31 unfertile males from 63 couples in which the "female factor" was ruled out as the cause of infertility. Sperm study according to WHO (1992) was carried out in all samples, in addition to: DNA study with acridine orange as fluorocrom, macrophage concentration by neutral red in a Neubauer camera, and detection of antispermatic antibodies with a mixed agglutination test (TAC II) (validated with Mar Screen-Fertility technologies). Sperm morphology was evaluated by Papanicolaou test. 19/31 selected sperm samples (61.3%) showed increased concentration of macrophages, 13 of them (41.9%) with denaturalized DNA, and 8 (25.8%) abnormal morphology. Six samples showed increased macrophage concentration and predominance of native DNA, whereas 11 samples showed increased macrophages and abnormal morphology. Among 18 (58.1%) samples showing antispermatic antibodies 14 (77.7%) had an increased concentration of macrophages. Statistical analysis resulted in a high correlation between macrophage concentration and increased percentage of spermatozoids with denaturalized DNA (p < 0.05). An increased concentration of macrophages is associated with the presence of antispermatic antibodies (p < 0.05). There was not evidence of significant association between concentration of macrophages and percentage of morphologically normal spermatozoids (p < 0.05). We can conclude that macrophages are present in human semen and participate in immunovigilance contributing to improve the seminal quality.

Changing pattern of the subcellular distribution of erythroblast macrophage protein (Emp) during macrophage differentiation.

PubMed

Soni, Shivani; Bala, Shashi; Kumar, Ajay; Hanspal, Manjit

2007-01-01

Erythroblast macrophage protein (Emp) mediates the attachment of erythroid cells to macrophages and is required for normal differentiation of both cell lineages. In erythroid cells, Emp is believed to be involved in nuclear extrusion, however, its role in macrophage differentiation is unknown. Information on the changes in the expression level and subcellular distribution of Emp in differentiating macrophages is essential for understanding the function of Emp. Macrophages of varying maturity were examined by immunofluorescence microscopy and biochemical methods. Our data show that Emp is expressed in all stages of maturation, but its localization pattern changes dramatically during maturation: in immature macrophages, a substantial fraction of Emp is associated with the nuclear matrix, whereas in more mature cells, Emp is expressed largely at cell surface. Pulse-chase experiments show that nascent Emp migrates intracellularly from the cytoplasm to the plasma membrane more efficiently in mature macrophages than in immature cells. Incubation of erythroid cells with macrophages in culture shows that erythroid cells attach to mature macrophages but not to immature macrophage precursors. Together, our data show that the temporal and spatial expression of Emp correlates with its role in erythroblastic island formation and suggest that Emp may be involved in multiple cellular functions.

*CHANGING PATTERN OF THE SUBCELLULAR DISTRIBUTION OF ERYTHROBLAST MACROPHAGE PROTEIN (EMP) DURING MACROPHAGE DIFFERENTIATION

PubMed Central

Soni, Shivani; Bala, Shashi; Kumar, Ajay; Hanspal, Manjit

2007-01-01

Erythroblast macrophage protein (Emp), mediates the attachment of erythroid cells to macrophages, and is required for normal differentiation of both cell lineages. In erythroid cells Emp is believed to be involved in nuclear extrusion however, its role in macrophage differentiation is unknown. Information on the changes in the expression level and subcellular distribution of Emp in differentiating macrophages is essential for understanding the function of Emp. Macrophages of varying maturity were examined by immunofluorescence microscopy and biochemical methods. Our data shows that Emp is expressed in all stages of maturation, but its localization pattern changes dramatically during maturation: in immature macrophages, a substantial fraction of Emp is associated with the nuclear matrix, whereas in more mature cells, Emp is expressed largely at cell surface. Pulse-chase experiments show that nascent Emp migrates intracellularly from the cytoplasm to the plasma membrane more efficiently in mature macrophages than in immature cells. Incubation of erythroid cells with macrophages in culture show that erythroid cells attach to mature macrophages but not to immature macrophage precursors. Together, our data shows that the temporal and spatial expression of Emp correlates with its role in erythroblastic island formation, and suggests that Emp may be involved in multiple cellular functions. PMID:17071116

Macrophages Exhibit a Large Repertoire of Activation States via Multiple Mechanisms of Macrophage-activating Factors.

PubMed

Sumiya, Y U; Inoue, Takahiro; Ishikawa, Mami; Inui, Toshio; Kuchiike, Daisuke; Kubo, Kentaro; Uto, Yoshihiro; Nishikata, Takahito

2016-07-01

Macrophages are important components of human defense systems and consequently key to antitumor immunity. Human-serum macrophage activation factor (serum MAF) can activate macrophages, making it a promising reagent for anticancer therapy. We established four different macrophage subtypes through introduction of different culture conditions to THP-1- and U937-derived macrophages. We assessed phagocytic activity to understand subtype responses to typical macrophage activation factors (MAFs) and the activation mechanisms of serum MAF. All four macrophage subtypes differed in their response to all MAFs. Moreover, serum MAF had two different activation mechanisms: N-acetylgalactosamine (GalNAc)-dependent and GalNAc-independent. Macrophage activation states and mechanisms are heterogeneous. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Cell Elasticity Determines Macrophage Function

PubMed Central

Patel, Naimish R.; Bole, Medhavi; Chen, Cheng; Hardin, Charles C.; Kho, Alvin T.; Mih, Justin; Deng, Linhong; Butler, James; Tschumperlin, Daniel; Fredberg, Jeffrey J.; Krishnan, Ramaswamy; Koziel, Henry

2012-01-01

Macrophages serve to maintain organ homeostasis in response to challenges from injury, inflammation, malignancy, particulate exposure, or infection. Until now, receptor ligation has been understood as being the central mechanism that regulates macrophage function. Using macrophages of different origins and species, we report that macrophage elasticity is a major determinant of innate macrophage function. Macrophage elasticity is modulated not only by classical biologic activators such as LPS and IFN-γ, but to an equal extent by substrate rigidity and substrate stretch. Macrophage elasticity is dependent upon actin polymerization and small rhoGTPase activation, but functional effects of elasticity are not predicted by examination of gene expression profiles alone. Taken together, these data demonstrate an unanticipated role for cell elasticity as a common pathway by which mechanical and biologic factors determine macrophage function. PMID:23028423

Neisseria gonorrhoeae Modulates Iron-Limiting Innate Immune Defenses in Macrophages

PubMed Central

Zughaier, Susu M.; Kandler, Justin L.; Shafer, William M.

2014-01-01

Neisseria gonorrhoeae is a strict human pathogen that causes the sexually transmitted infection termed gonorrhea. The gonococcus can survive extracellularly and intracellularly, but in both environments the bacteria must acquire iron from host proteins for survival. However, upon infection the host uses a defensive response by limiting the bioavailability of iron by a number of mechanisms including the enhanced expression of hepcidin, the master iron-regulating hormone, which reduces iron uptake from the gut and retains iron in macrophages. The host also secretes the antibacterial protein NGAL, which sequesters bacterial siderophores and therefore inhibits bacterial growth. To learn whether intracellular gonococci can subvert this defensive response, we examined expression of host genes that encode proteins involved in modulating levels of intracellular iron. We found that N. gonorrhoeae can survive in association (tightly adherent and intracellular) with monocytes and macrophages and upregulates a panel of its iron-responsive genes in this environment. We also found that gonococcal infection of human monocytes or murine macrophages resulted in the upregulation of hepcidin, NGAL, and NRAMP1 as well as downregulation of the expression of the gene encoding the short chain 3-hydroxybutyrate dehydrogenase (BDH2); BDH2 catalyzes the production of the mammalian siderophore 2,5-DHBA involved in chelating and detoxifying iron. Based on these findings, we propose that N. gonorrhoeae can subvert the iron-limiting innate immune defenses to facilitate iron acquisition and intracellular survival. PMID:24489950

Resident alveolar macrophages are master regulators of arrested alveolarization in experimental bronchopulmonary dysplasia.

PubMed

Kalymbetova, Tatiana V; Selvakumar, Balachandar; Rodríguez-Castillo, José Alberto; Gunjak, Miša; Malainou, Christina; Heindl, Miriam Ruth; Moiseenko, Alena; Chao, Cho-Ming; Vadász, István; Mayer, Konstantin; Lohmeyer, Jürgen; Bellusci, Saverio; Böttcher-Friebertshäuser, Eva; Seeger, Werner; Herold, Susanne; Morty, Rory E

2018-06-01

Trophic functions for macrophages are emerging as key mediators of developmental processes, including bone, vessel, and mammary gland development. Yolk sac-derived macrophages mature in the distal lung shortly after birth. Myeloid-lineage macrophages are recruited to the lung and are activated under pathological conditions. These pathological conditions include bronchopulmonary dysplasia (BPD), a common complication of preterm birth characterized by stunted lung development, where the formation of alveoli is blocked. No study has addressed causal roles for immune cells in lung alveolarization. We employed antibody-based and transgenic death receptor-based depletion approaches to deplete or prevent lung recruitment of immune cell populations in a hyperoxia-based mouse model of BPD. Neither neutrophils nor exudate macrophages (which might include lung interstitial macrophages) contributed to structural perturbations to the lung that were provoked by hyperoxia; however, cells of the Csf1r-expressing monocyte/macrophage lineage were implicated as causal mediators of stunted lung development. We propose that resident alveolar macrophages differentiate into a population of CD45 + CD11c + SiglecF + CD11b + CD68 + MHCII + cells, which are activated by hyperoxia, and contribute to disturbances to the structural development of the immature lung. This is the first report that causally implicates immune cells in pathological disturbances to postnatal lung organogenesis. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Autophagy enhances NFκB activity in specific tissue macrophages by sequestering A20 to boost antifungal immunity

PubMed Central

Kanayama, Masashi; Inoue, Makoto; Danzaki, Keiko; Hammer, Gianna; He, You-Wen; Shinohara, Mari L.

2014-01-01

Immune responses must be well restrained in a steady state to avoid excessive inflammation. However, such restraints are quickly removed to exert anti-microbial responses. Here, we report a role of autophagy in an early host anti-fungal response by enhancing NFκB activity through A20 sequestration. Enhancement of NFκB activation is achieved by autophagic depletion of A20, an NFκB inhibitor, in F4/80hi macrophages in the spleen, peritoneum, and kidney. We show that p62, an autophagic adaptor protein, captures A20 to sequester it in the autophagosome. This allows the macrophages to release chemokines to recruit neutrophils. Indeed, mice lacking autophagy in myeloid cells show higher susceptibility to Candida albicans infection due to impairment in neutrophil recruitment. Thus, at least in the specific aforementioned tissues, autophagy appears to break A20-dependent suppression in F4/80hi macrophages, which express abundant A20 and contribute to the initiation of efficient innate immune responses. PMID:25609235

Proprotein convertase 1/3 inhibited macrophages: A novel therapeutic based on drone macrophages.

PubMed

Duhamel, Marie; Rodet, Franck; Murgoci, Adriana; Wisztorski, Maxence; Day, Robert; Fournier, Isabelle; Salzet, Michel

2016-06-01

We demonstrated here thanks to proteomic, that proprotein convertase 1/3 knockdown macrophages present all the characteristic of activated pro-inflammatory macrophages. TLR4 and TLR9 signaling pathways can be enhanced leading to the secretion of pro-inflammatory factors and antitumor factors. We can control their activation by controlling one enzyme, PC1/3. In a tumor context, PC1/3 inhibition in macrophages may reactivate them and lead to a cytokine storm after stimulation "at distance" with a TLR ligand. Therefore, we name these proprotein convertase inhibited macrophages the "drone macrophages". They constitute an innovative cell therapy to treat efficiently tumors.

Susceptibility of bone marrow-derived macrophages to influenza virus infection is dependent on macrophage phenotype.

PubMed

Campbell, Gillian M; Nicol, Marlynne Q; Dransfield, Ian; Shaw, Darren J; Nash, Anthony A; Dutia, Bernadette M

2015-10-01

The role of the macrophage in influenza virus infection is complex. Macrophages are critical for resolution of influenza virus infections but implicated in morbidity and mortality in severe infections. They can be infected with influenza virus and consequently macrophage infection is likely to have an impact on the host immune response. Macrophages display a range of functional phenotypes, from the prototypical pro-inflammatory classically activated cell to alternatively activated anti-inflammatory macrophages involved in immune regulation and wound healing. We were interested in how macrophages of different phenotype respond to influenza virus infection and therefore studied the infection of bone marrow-derived macrophages (BMDMs) of classical and alternative phenotype in vitro. Our results show that alternatively activated macrophages are more readily infected and killed by the virus than classically activated. Classically activated BMDMs express the pro-inflammatory markers inducible nitric oxide synthase (iNOS) and TNF-α, and TNF-α expression was further upregulated following infection. Alternatively activated macrophages express Arginase-1 and CD206; however, following infection, expression of these markers was downregulated whilst expression of iNOS and TNF-α was upregulated. Thus, infection can override the anti-inflammatory state of alternatively activated macrophages. Importantly, however, this results in lower levels of pro-inflammatory markers than those produced by classically activated cells. Our results showed that macrophage phenotype affects the inflammatory macrophage response following infection, and indicated that modulating the macrophage phenotype may provide a route to develop novel strategies to prevent and treat influenza virus infection.

Isolation and Differentiation of Murine Macrophages.

PubMed

Rios, Francisco J; Touyz, Rhian M; Montezano, Augusto C

2017-01-01

Macrophages play a major role in inflammation, wound healing, and tissue repair. Infiltrated monocytes differentiate into different macrophage subtypes with protective or pathogenic activities in vascular lesions. In the heart and vascular tissues, pathological activation promotes cardiovascular inflammation and remodeling and there is increasing evidence that macrophages play important mechanisms in this environment. Primary murine macrophages can be obtained from: bone marrow by different treatments (granulocyte-macrophage colony-stimulating factor-GM-CSF, macrophage colony-stimulating factor-M-CSF or supernatant of murine fibroblast L929), peritoneal cavity (resident or thioglycolate elicit macrophages), from the lung (alveolar macrophages) or from adipose tissue. In this chapter we describe some protocols to obtain primary murine macrophages and how to identify a pure macrophage population or activation phenotypes using different markers.

Probiotic Bacillus amyloliquefaciens mediate M1 macrophage polarization in mouse bone marrow-derived macrophages.

PubMed

Ji, Jian; Hu, Sheng-Lan; Cui, Zhi-Wen; Li, Wei-Fen

2013-05-01

Depending on the microenvironment, macrophages can acquire distinct functional phenotypes, referred to as classically activated M1 and M2. M1 macrophages are considered potent effector cells that kill intracellular pathogens, and M2 macrophages promote the resolution of wound healing. In this study, we are interested to know whether probiotic Bacillus amyloliquefaciens (Ba) can induce macrophages polarization. Real-time fluorescence PCR analysis demonstrated that the expression of IL-1β, iNOS, TNF-α and IL-6 genes for M1 macrophages was significantly increased at 1.5 h after probiotic Ba treatment compared to the probiotic Ba-free treatment (P < 0.01), whereas the expression of M2 macrophage marker genes (Arg1, Fizz1, MR, Ym1) was decreased (P < 0.05). Furthermore, the phagocytic activity was dramatically increased in the Ba-treated BMDMs using a FITC-dextran endocytosis assay. Together, these findings indicated that probiotic Ba facilitated polarization of M1 macrophages and enhanced its phagocytic capacity. The results expanded our knowledge about probiotic function-involved macrophage polarization.

In vitro and intra-macrophage gene expression by Rhodococcus equi strain 103.

PubMed

Rahman, Md Tanvir; Parreira, Valeria; Prescott, John F

2005-09-30

Rhodococcus equi is a facultative intracellular respiratory pathogen of foals that persists and multiplies within macrophages. In foals, virulence is associated with 80-90 kb plasmids, which include a pathogenicity island (PI) containing the virulence-associated protein (vap) gene family, but detailed understanding of the basis of virulence is still poor. A 60 spot-based DNA microarray was developed containing eight PI genes and 42 chromosomal putative virulence or virulence-associated genes selected from a recent partial genome sequence in order to study transcription of these genes by R. equi grown inside macrophages and under in vitro conditions thought to simulate those of macrophages. In addition to seven PI genes, nine chromosomal genes involved in fatty acid and lipid metabolism (choD, fadD13, fbpB), heme biosynthesis (hemE), iron utilization (mbtF), heat shock resistance and genes encoding chaperones (clpB, groEL), a sigma factor (sigK), and a transcriptional regulator (moxR) were significantly induced in R. equi growing inside macrophages. The pattern of R. equi chromosomal genes significantly transcribed inside macrophages largely differed from those transcribed under in vitro conditions (37 degrees C, pH 5.0 or 50mM H2O2 for 30 min). This study has identified genes, other than those of the virulence plasmid, the transcription of which is enhanced within equine macrophages. These genes should be investigated further to improve understanding of how this organism survives intracellularly.

Gc protein-derived macrophage activating factor (GcMAF): isoelectric focusing pattern and tumoricidal activity.

PubMed

Mohamad, Saharuddin Bin; Nagasawa, Hideko; Sasaki, Hideyuki; Uto, Yoshihiro; Nakagawa, Yoshinori; Kawashima, Ken; Hori, Hitoshi

2003-01-01

Gc protein is the precursor for Gc protein-derived macrophage activating factor (GcMAF), with three phenotypes: Gc1f, Gc1s and Gc2, based on its electrophoretic mobility. The difference in electrophoretic mobility is because of the difference in its posttranslational sugar moiety composition. We compared the difference between Gc protein and GcMAF electrophoretic mobility using the isoelectric focusing (IEF) method. The tumoricidal activity of GcMAF-treated macrophage was evaluated after coculture with L-929 cell. The tumoricidal mechanism was investigated using TNF bioassay and nitric oxide (NO) release. The difference in Gc protein and GcMAF electrophoretic mobility was detected. The tumoricidal activity of GcMAF-treated macrophage was detected, but no release of TNF and NO was detected. The difference of isoelectric focusing mobility in Gc protein and GcMAF would be useful to develop a GcMAF detection method. GcMAF increased macrophage tumoricidal activity but TNF and NO release were not involved in the mechanism.

Direct evidence of macrophage differentiation from bone marrow cells in the liver: a possible origin of Kupffer cells.

PubMed

Takezawa, R; Watanabe, Y; Akaike, T

1995-12-01

Controversy has surrounded origin and differentiation of tissue macrophages. We directly demonstrate the differentiation of bone marrow cells into macrophages in the liver in vivo using a cell-labeling fluorescence dye, PKH-26. Bone marrow cells labeled with PKH26 were intravenously injected into syngenic mice, and these cells were tracked by flow cytometric analysis. The majority of the labeled cells were detected only in the liver after 4 days. Interestingly, antigens specific for macrophage lineage cells (F4/80, Fc gamma RII, and CD14) were detected on the liver-accumulated cells only 4 h after the injection. The pattern of the antigen expression changed to that of Kupffer cells (F4/80+, Fc gamma RII+, Mac-1-) after 4 days and remained so thereafter. These labeled cells in the liver were esterase staining-positive and showed phagocytic activity at day 7. The number of labeled cells among the Kupffer cells in the liver increased with days after injection. This indicates that bone marrow cells accumulate in the liver and differentiate into liver macrophages on site. Roles of factors secreted from hepatocytes are also discussed.

Alternatively activated macrophages (M2 macrophages) in the skin of patient with localized scleroderma.

PubMed

Higashi-Kuwata, Nobuyo; Makino, Takamitsu; Inoue, Yuji; Takeya, Motohiro; Ihn, Hironobu

2009-08-01

Localized scleroderma is a connective tissue disorder that is limited to the skin and subcutaneous tissue. Macrophages have been reported to be particularly activated in patients with skin disease including systemic sclerosis and are potentially important sources for fibrosis-inducing cytokines, such as transforming growth factor beta. To clarify the features of immunohistochemical characterization of the immune cell infiltrates in localized scleroderma focusing on macrophages, skin biopsy specimens were analysed by immunohistochemistry. The number of cells stained with monoclonal antibodies, CD68, CD163 and CD204, was calculated. An evident macrophage infiltrate and increased number of alternatively activated macrophages (M2 macrophages) in their fibrotic areas were observed along with their severity of inflammation. This study revealed that alternatively activated macrophages (M2 macrophages) may be a potential source of fibrosis-inducing cytokines in localized scleroderma, and may play a crucial role in the pathogenesis of localized scleroderma.

Brazilian Red Propolis Attenuates Inflammatory Signaling Cascade in LPS-Activated Macrophages

PubMed Central

Bueno-Silva, Bruno; Kawamoto, Dione; Ando-Suguimoto, Ellen S.; Alencar, Severino M.; Rosalen, Pedro L.; Mayer, Marcia P. A.

2015-01-01

Although previous studies suggested an anti-inflammatory property of Brazilian red propolis (BRP), the mechanisms involved in the anti-inflammatory effects of BRP and its activity on macrophages were still not elucidated. This study aimed to evaluate whether BRP attenuates the inflammatory effect of LPS on macrophages and to investigate its underlying mechanisms. BRP was added to RAW 264.7 murine macrophages after activation with LPS. NO production, cell viability, cytokines profile were evaluated. Activation of inflammatory signaling pathways and macrophage polarization were determined by RT-qPCR and Western blot. BRP at 50 μg/ml inhibited NO production by 78% without affecting cell viability. Cd80 and Cd86 were upregulated whereas mrc1 was down regulated by BRP indicating macrophage polarization at M1. BRP attenuated the production of pro-inflammatory mediators IL-12, GM-CSF, IFN-Ɣ, IL-1β in cell supernatants although levels of TNF- α and IL-6 were slightly increased after BRP treatment. Levels of IL-4, IL-10 and TGF-β were also reduced by BRP. BRP significantly reduced the up-regulation promoted by LPS of transcription of genes in inflammatory signaling (Pdk1, Pak1, Nfkb1, Mtcp1, Gsk3b, Fos and Elk1) and of Il1β and Il1f9 (fold-change rate > 5), which were further confirmed by the inhibition of NF-κB and MAPK signaling pathways. Furthermore, the upstream adaptor MyD88 adaptor-like (Mal), also known as TIRAP, involved in TLR2 and TLR4 signaling, was down- regulated in BRP treated LPS-activated macrophages. Given that BRP inhibited multiple signaling pathways in macrophages involved in the inflammatory process activated by LPS, our data indicated that BRP is a noteworthy food-source for the discovery of new bioactive compounds and a potential candidate to attenuate exhacerbated inflammatory diseases. PMID:26660901

Antioxidative defence mechanisms against reactive oxygen species in bovine retained and not-retained placenta: activity of glutathione peroxidase, glutathione transferase, catalase and superoxide dismutase.

PubMed

Kankofer, M

2001-05-01

Glutathione peroxidase (GSH-Px), glutathione transferase (GSH-Tr), catalase (CAT) and superoxide dismutase (SOD)-the members of enzymatic antioxidative defence mechanisms against reactive oxygen species-may play an important role in proper or improper release of bovine fetal membranes. The aim of the following study was the determination of GSH-Px, GSH-Tr, CAT and SOD activity in order to define antioxidative status of bovine placenta during retention of fetal membranes (RFM) in cows. Placental samples were collected immediately after spontaneous parturition or during caesarean section before term and at term and divided into six groups as follows: A: caesarean section before term without RFM; B: caesarean section before term with RFM; C: caesarean section at term without RFM; D: caesarean section at term with RFM; E: spontaneous delivery at term without RFM; F: spontaneous delivery at term with RFM. The enzyme activities in placental homogenates were measured spectrophotometrically. GSH-Px activity was statistically significantly higher in fetal than in maternal placenta in all examined groups, increased towards parturition and was higher in caesarean section groups than spontaneous delivery groups. Statistically significantly higher activities were noticed in retained than not-retained placentae. GSH-Tr activity was significantly lower in fetal than in maternal placenta. In preterm groups, the activity was statistically significantly higher in retained than not retained placenta. In term groups, the opposite relationship was observed, higher values in caesarean section groups than spontaneous delivery were noticed. CAT activity was statistically significantly higher in fetal than in maternal part of placenta in all groups examined. The highest values in C and D groups and the differences between retained and not-retained placenta were observed. SOD exhibited the highest values in preterm placenta and alterations between retained and not-retained fetal membranes

Immunotherapy of HIV-infected patients with Gc protein-derived macrophage activating factor (GcMAF).

PubMed

Yamamoto, Nobuto; Ushijima, Naofumi; Koga, Yoshihiko

2009-01-01

Serum Gc protein (known as vitamin D3-binding protein) is the precursor for the principal macrophage activating factor (MAF). The MAF precursor activity of serum Gc protein of HIV-infected patients was lost or reduced because Gc protein is deglycosylated by alpha-N-acetylgalactosaminidase (Nagalase) secreted from HIV-infected cells. Therefore, macrophages of HIV-infected patients having deglycosylated Gc protein cannot be activated, leading to immunosuppression. Since Nagalase is the intrinsic component of the envelope protein gp120, serum Nagalase activity is the sum of enzyme activities carried by both HIV virions and envelope proteins. These Nagalase carriers were already complexed with anti-HIV immunoglobulin G (IgG) but retained Nagalase activity that is required for infectivity. Stepwise treatment of purified Gc protein with immobilized beta-galactosidase and sialidase generated the most potent macrophage activating factor (termed GcMAF), which produces no side effects in humans. Macrophages activated by administration of 100 ng GcMAF develop a large amount of Fc-receptors as well as an enormous variation of receptors that recognize IgG-bound and unbound HIV virions. Since latently HIV-infected cells are unstable and constantly release HIV virions, the activated macrophages rapidly intercept the released HIV virions to prevent reinfection resulting in exhaustion of infected cells. After less than 18 weekly administrations of 100 ng GcMAF for nonanemic patients, they exhibited low serum Nagalase activities equivalent to healthy controls, indicating eradication of HIV-infection, which was also confirmed by no infectious center formation by provirus inducing agent-treated patient PBMCs. No recurrence occurred and their healthy CD + cell counts were maintained for 7 years.

Macrophage Depletion Attenuates Extracellular Matrix Deposition and Ductular Reaction in a Mouse Model of Chronic Cholangiopathies

PubMed Central

Syn, Wing-Kin; Lagaisse, Kimberly; van Hul, Noemi; Heindryckx, Femke; Sowa, Jan-Peter; Peeters, Liesbeth; Van Vlierberghe, Hans; Leclercq, Isabelle A.; Canbay, Ali

2016-01-01

Chronic cholangiopathies, such as primary and secondary sclerosing cholangitis, are progressive disease entities, associated with periportal accumulation of inflammatory cells, encompassing monocytes and macrophages, peribiliary extracellular matrix (ECM) deposition and ductular reaction (DR). This study aimed to elucidate the relevance of macrophages in the progression of chronic cholangiopathies through macrophage depletion in a 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) mouse model. One group of mice received a single i.p. injection of Clodronate encapsulated liposomes (CLOLipo) at day 7 of a 14 day DDC treatment, while control animals were co-treated with PBSLipo instead. Mice were sacrificed after 7 or respectively 14 days of treatment for immunohistochemical assessment of macrophage recruitment (F4/80), ECM deposition (Sirius Red, Laminin) and DR (CK19). Macrophage depletion during a 14 day DDC treatment resulted in a significant inhibition of ECM deposition. Porto-lobular migration patterns of laminin-rich ECM and ductular structures were significantly attenuated and a progression of DR was effectively inhibited by macrophage depletion. CLOLipo co-treatment resulted in a confined DR to portal regions without amorphous cell clusters. This study suggests that therapeutic options selectively directed towards macrophages might represent a feasible treatment for chronic cholestatic liver diseases. PMID:27618307

Biology of Bony Fish Macrophages

PubMed Central

Hodgkinson, Jordan W.; Grayfer, Leon; Belosevic, Miodrag

2015-01-01

Macrophages are found across all vertebrate species, reside in virtually all animal tissues, and play critical roles in host protection and homeostasis. Various mechanisms determine and regulate the highly plastic functional phenotypes of macrophages, including antimicrobial host defenses (pro-inflammatory, M1-type), and resolution and repair functions (anti-inflammatory/regulatory, M2-type). The study of inflammatory macrophages in immune defense of teleosts has garnered much attention, and antimicrobial mechanisms of these cells have been extensively studied in various fish models. Intriguingly, both similarities and differences have been documented for the regulation of lower vertebrate macrophage antimicrobial defenses, as compared to what has been described in mammals. Advances in our understanding of the teleost macrophage M2 phenotypes likewise suggest functional conservation through similar and distinct regulatory strategies, compared to their mammalian counterparts. In this review, we discuss the current understanding of the molecular mechanisms governing teleost macrophage functional heterogeneity, including monopoetic development, classical macrophage inflammatory and antimicrobial responses as well as alternative macrophage polarization towards tissues repair and resolution of inflammation. PMID:26633534

Biology of Bony Fish Macrophages.

PubMed

Hodgkinson, Jordan W; Grayfer, Leon; Belosevic, Miodrag

2015-11-30

Macrophages are found across all vertebrate species, reside in virtually all animal tissues, and play critical roles in host protection and homeostasis. Various mechanisms determine and regulate the highly plastic functional phenotypes of macrophages, including antimicrobial host defenses (pro-inflammatory, M1-type), and resolution and repair functions (anti-inflammatory/regulatory, M2-type). The study of inflammatory macrophages in immune defense of teleosts has garnered much attention, and antimicrobial mechanisms of these cells have been extensively studied in various fish models. Intriguingly, both similarities and differences have been documented for the regulation of lower vertebrate macrophage antimicrobial defenses, as compared to what has been described in mammals. Advances in our understanding of the teleost macrophage M2 phenotypes likewise suggest functional conservation through similar and distinct regulatory strategies, compared to their mammalian counterparts. In this review, we discuss the current understanding of the molecular mechanisms governing teleost macrophage functional heterogeneity, including monopoetic development, classical macrophage inflammatory and antimicrobial responses as well as alternative macrophage polarization towards tissues repair and resolution of inflammation.

Macrophage cell lines derived from major histocompatibility complex II-negative mice

NASA Technical Reports Server (NTRS)

Beharka, A. A.; Armstrong, J. W.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

1998-01-01

Two bone-marrow-derived macrophage cell lines, C2D and C2Dt, were isolated from major histocompatibility class II negative knock-out mice. The C2D cell line was stabilized by continuous culture in colony-stimulating factor-1 and the C2Dt cell line was transformed with SV40 virus large T antigen. These cells exhibited phenotypic properties of macrophages including morphology and expression of Mac 1 and Mac 2 cell surface molecules. These cells also had comparable growth to the bone-marrow-derived macrophage cell line B6MP102. These new cell lines were not spontaneously cytotoxic and were only capable of modest killing of F5b tumor cells when stimulated with LPS and interferon-gamma, but not when stimulated with LPS alone or with staphylococcal exotoxin. C2D and C2Dt cells phagocytosed labeled Staphylococcus aureus similarly to B6MP102 cells but less well than C2D peritoneal macrophages. These cell lines secreted interleukin-6, but not tumor necrosis factor or nitric oxide in response to LPS or staphlococcal enterotoxins A or B C2D(t) cells were tumorigenic in C2D and C57BL/6J mice but C2D cells were not. These data suggest that macrophage cell lines can be established from bone marrow cells of major histocompatibility complex II-negative mice.

Glutamine Modulates Macrophage Lipotoxicity

PubMed Central

He, Li; Weber, Kassandra J.; Schilling, Joel D.

2016-01-01

Obesity and diabetes are associated with excessive inflammation and impaired wound healing. Increasing evidence suggests that macrophage dysfunction is responsible for these inflammatory defects. In the setting of excess nutrients, particularly dietary saturated fatty acids (SFAs), activated macrophages develop lysosome dysfunction, which triggers activation of the NLRP3 inflammasome and cell death. The molecular pathways that connect lipid stress to lysosome pathology are not well understood, but may represent a viable target for therapy. Glutamine uptake is increased in activated macrophages leading us to hypothesize that in the context of excess lipids glutamine metabolism could overwhelm the mitochondria and promote the accumulation of toxic metabolites. To investigate this question we assessed macrophage lipotoxicity in the absence of glutamine using LPS-activated peritoneal macrophages exposed to the SFA palmitate. We found that glutamine deficiency reduced lipid induced lysosome dysfunction, inflammasome activation, and cell death. Under glutamine deficient conditions mTOR activation was decreased and autophagy was enhanced; however, autophagy was dispensable for the rescue phenotype. Rather, glutamine deficiency prevented the suppressive effect of the SFA palmitate on mitochondrial respiration and this phenotype was associated with protection from macrophage cell death. Together, these findings reveal that crosstalk between activation-induced metabolic reprogramming and the nutrient microenvironment can dramatically alter macrophage responses to inflammatory stimuli. PMID:27077881

Bioelectric modulation of macrophage polarization

NASA Astrophysics Data System (ADS)

Li, Chunmei; Levin, Michael; Kaplan, David L.

2016-02-01

Macrophages play a critical role in regulating wound healing and tissue regeneration by changing their polarization state in response to local microenvironmental stimuli. The native roles of polarized macrophages encompass biomaterials and tissue remodeling needs, yet harnessing or directing the polarization response has been largely absent as a potential strategy to exploit in regenerative medicine to date. Recent data have revealed that specific alteration of cells’ resting potential (Vmem) is a powerful tool to direct proliferation and differentiation in a number of complex tissues, such as limb regeneration, craniofacial patterning and tumorigenesis. In this study, we explored the bioelectric modulation of macrophage polarization by targeting ATP sensitive potassium channels (KATP). Glibenclamide (KATP blocker) and pinacidil (KATP opener) treatment not only affect macrophage polarization, but also influence the phenotype of prepolarized macrophages. Furthermore, modulation of cell membrane electrical properties can fine-tune macrophage plasticity. Glibenclamide decreased the secretion and gene expression of selected M1 markers, while pinacidil augmented M1 markers. More interestingly, glibencalmide promoted macrophage alternative activation by enhancing certain M2 markers during M2 polarization. These findings suggest that control of bioelectric properties of macrophages could offer a promising approach to regulate macrophage phenotype as a useful tool in regenerative medicine.

Effects of macrophage colony-stimulating factor on macrophages and their related cell populations in the osteopetrosis mouse defective in production of functional macrophage colony-stimulating factor protein.

PubMed Central

Umeda, S.; Takahashi, K.; Shultz, L. D.; Naito, M.; Takagi, K.

1996-01-01

The development of macrophage populations in osteopetrosis (op) mutant mice defective in production of functional macrophage colony-stimulating factor (M-CSF) and the response of these cell populations to exogenous M-CSF were used to classify macrophages into four groups: 1) monocytes, monocyte-derived macrophages, and osteoclasts, 2) MOMA-1-positive macrophages, 3) ER-TR9-positive macrophages, and 4) immature tissue macrophages. Monocytes, monocyte-derived macrophages, osteoclasts in bone, microglia in brain, synovial A cells, and MOMA-1- or ER-TR9-positive macrophages were deficient in op/op mice. The former three populations expanded to normal levels in op/op mice after daily M-CSF administration, indicating that they are developed and differentiated due to the effect of M-CSF supplied humorally. In contrast, the other cells did not respond or very slightly responded to M-CSF, and their development seems due to either M-CSF produced in situ or expression of receptor for M-CSF. Macrophages present in tissues of the mutant mice were immature and appear to be regulated by either granulocyte/macrophage colony-stimulating factor and/or interleukin-3 produced in situ or receptor expression. Northern blot analysis revealed different expressions of GM-CSF and IL-3 mRNA in various tissues of the op/op mice. However, granulocyte/macrophage colony-stimulating factor and interleukin-3 in serum were not detected by enzyme-linked immunosorbent assay. The immature macrophages differentiated and matured into resident macrophages after M-CSF administration, and some of these cells proliferated in response to M-CSF. Images Figure 4 Figure 6 Figure 8 Figure 10 Figure 11 PMID:8701995

Chemotherapy-Induced Macrophage Infiltration into Tumors Enhances Nanographene-Based Photodynamic Therapy.

PubMed

Zhao, Yang; Zhang, Chenran; Gao, Liquan; Yu, Xinhe; Lai, Jianhao; Lu, Dehua; Bao, Rui; Wang, Yanpu; Jia, Bing; Wang, Fan; Liu, Zhaofei

2017-11-01

Increased recruitment of tumor-associated macrophages (TAM) to tumors following chemotherapy promotes tumor resistance and recurrence and correlates with poor prognosis. TAM depletion suppresses tumor growth, but is not highly effective due to the effects of tumorigenic mediators from other stromal sources. Here, we report that adoptive macrophage transfer led to a dramatically enhanced photodynamic therapy (PDT) effect of 2-(1-hexyloxyethyl)-2-devinyl pyropheophor-bide-alpha (HPPH)-coated polyethylene glycosylated nanographene oxide [GO(HPPH)-PEG] by increasing its tumor accumulation. Moreover, tumor treatment with commonly used chemotherapeutic drugs induced an increase in macrophage infiltration into tumors, which also enhanced tumor uptake and the PDT effects of GO(HPPH)-PEG, resulting in tumor eradication. Macrophage recruitment to tumors after chemotherapy was visualized noninvasively by near-infrared fluorescence and single-photon emission CT imaging using F4/80-specific imaging probes. Our results demonstrate that chemotherapy combined with GO(HPPH)-PEG PDT is a promising strategy for the treatment of tumors, especially those resistant to chemotherapy. Furthermore, TAM-targeted molecular imaging could potentially be used to predict the efficacy of combination therapy and select patients who would most benefit from this treatment approach. Cancer Res; 77(21); 6021-32. ©2017 AACR . ©2017 American Association for Cancer Research.

The effects of a mineral trioxide aggregate-based sealer on the production of reactive oxygen species, nitrogen species and cytokines by two macrophage subtypes.

PubMed

Braga, J M; Oliveira, R R; Martins, R C; Ribeiro Sobrinho, A P

2014-10-01

To test the effects of a mineral trioxide aggregate-based sealer (MTA Fillapex(®)) and MTA (MTA-Ângelus(®)) on viability and on the production of cytokines, reactive oxygen species (ROS) and nitrogen species (NO) by M1 and M2 inflammatory macrophages. M1 (from C57BL/6 mice) and M2 (from BALB/c mice) peritoneal inflammatory macrophages were obtained and cultured in vitro in the presence of original and diluted extracts of MTA and MTA Fillapex (FLPX). The cell viability, ROS release and the release of tumour necrosis factor-a, interleukin (IL)-12, IL-10 and NO in response to stimulation with interferon-γ and Fusobacterium nucleatum or Peptostreptococcus anaerobius were evaluated. The data were analysed using the Mann-Whitney test and Student's t-test. Fillapex was cytotoxic at the highest concentrations (1:1;1:2) and decreased the viability (P < 0.05) of both macrophage types (<20%). MTA did not interfere with cellular viability. FLPX inhibited the release of ROS and decreased NO release in F. nucleatum and P. anaerobius -stimulated M1 and M2 macrophages (≤25 μ mol L(-1)). F. nucleatum-stimulated M2 macrophage cultures released lower levels of TNF-α when FLPX was added (≤1 ng mL(-1)). M2 macrophages released higher (>5 ng mL(-1)) levels of IL-10 than M1 macrophages. Only M1 macrophage cultures produced IL-12p70. Fillapex impaired effector immune responses during inflammation (M1 macrophages), as well as during healing (M2 macrophages) responses. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

A vitellogenic-like carboxypeptidase expressed by human macrophages is localized in endoplasmic reticulum and membrane ruffles

PubMed Central

Harris, James; Schwinn, Nicole; Mahoney, James A; Lin, Hsi-Hsien; Shaw, Michael; Howard, Chris J; da Silva, Rosangela P; Gordon, Siamon

2006-01-01

Carboxypeptidase, vitellogenic-like (CPVL) is a serine carboxypeptidase of unknown function that was first characterized in human macrophages. Initial studies suggested that CPVL is largely restricted to the monocytic lineage, although it may also be expressed by cells outside the immune system. Here, we use a new monoclonal antibody to characterize the properties and localization of CPVL in human macrophages to elucidate a possible function for the protease. CPVL is up-regulated during the maturation of monocytes (MO) to macrophages, although the protein can be seen in both. In primary macrophages, CPVL is glycosylated with high mannose residues and colocalizes with markers for endoplasmic reticulum, while in MO it is more disperse and less clearly associated with endoplasmic reticulum. CPVL is highly expressed in lamellipodia and membrane ruffles, which also concentrate markers of the secretory pathway (MIP-1α and tumour necrosis factor-α) and major histocompatibility complex (MHC) class I and II molecules. CPVL can be seen on early latex bead and Candida albicans phagosomes, but it is not retained in the maturing phagosome, unlike MHC class I/II. CPVL has a mixed cytosolic and membrane-associated localization but is not detectable on the outer plasma membrane. We propose that CPVL may be involved in antigen processing, the secretory pathway and/or in actin remodelling and lamellipodium formation. PMID:16436111

Interactions between neutrophils and macrophages promote macrophage killing of rat muscle cells in vitro

NASA Technical Reports Server (NTRS)

Nguyen, Hal X.; Tidball, James G.

2003-01-01

Current evidence indicates that the physiological functions of inflammatory cells are highly sensitive to their microenvironment, which is partially determined by the inflammatory cells and their potential targets. In the present investigation, interactions between neutrophils, macrophages and muscle cells that may influence muscle cell death are examined. Findings show that in the absence of macrophages, neutrophils kill muscle cells in vitro by superoxide-dependent mechanisms, and that low concentrations of nitric oxide (NO) protect against neutrophil-mediated killing. In the absence of neutrophils, macrophages kill muscle cells through a NO-dependent mechanism, and the presence of target muscle cells causes a three-fold increase in NO production by macrophages, with no change in the concentration of inducible nitric oxide synthase. Muscle cells that are co-cultured with both neutrophils and macrophages in proportions that are observed in injured muscle show cytotoxicity through a NO-dependent, superoxide-independent mechanism. Furthermore, the concentration of myeloid cells that is necessary for muscle killing is greatly reduced in assays that use mixed myeloid cell populations, rather than uniform populations of neutrophils or macrophages. These findings collectively show that the magnitude and mechanism of muscle cell killing by myeloid cells are modified by interactions between muscle cells and neutrophils, between muscle cells and macrophages and between macrophages and neutrophils.

MiR-146a modulates macrophage polarization by inhibiting Notch1 pathway in RAW264.7 macrophages.

PubMed

Huang, Cheng; Liu, Xue-Jiao; QunZhou; Xie, Juan; Ma, Tao-Tao; Meng, Xiao-Ming; Li, Jun

2016-03-01

Macrophages are heterogeneous and plastic cells which are able to undergo dynamic transition between M1 and M2 polarized phenotypes in response to the microenvironment signals. However, the underlying molecular mechanisms of macrophage polarization are still obscure. In the current study, it was revealed that miR-146a might play a pivotal role in macrophage polarization. As our results indicated, miR-146a was highly expressed in M2 macrophages rather than M1 macrophages. Over-expression of miR-146a resulted in significantly decreased production of pro-inflammatory cytokines including iNOS and TNF-α in M1 macrophages, while increased production of M2 marker genes such as Arg1 and CD206 in M2 macrophages. In contrast, knockdown of miR-146a promoted M1 macrophage polarization but diminished M2 macrophage polarization. Mechanistically, it was revealed that miR-146a modulated macrophage polarization by targeting Notch1. Of note, PPARγ was responsible as another target for miR-146a-mediated macrophage polarization. Taken together, it was suggested that miR-146a might serve as a molecular regulator in macrophage polarization and is a potential therapeutic target for inflammatory diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

Increasing trend in retained rectal foreign bodies

PubMed Central

Ayantunde, Abraham A; Unluer, Zynep

2016-01-01

AIM To highlight the rising trend in hospital presentation of foreign bodies retained in the rectum over a 5-year period. METHODS Retrospective review of the cases of retained rectal foreign bodies between 2008 and 2012 was performed. Patients’ clinical data and yearly case presentation with data relating to hospital episodes were collected. Data analysis was by SPSS Inc. Chicago, IL, United States. RESULTS Twenty-five patients presented over a 5-year period with a mean age of 39 (17-62) years and M: F ratio of 2:1. A progressive rise in cases was noted from 2008 to 2012 with 3, 4, 4, 6, 8 recorded patients per year respectively. The majority of the impacted rectal objects were used for self-/partner-eroticism. The commonest retained foreign bodies were sex vibrators and dildos. Ninty-six percent of the patients required extraction while one passed spontaneously. Two and three patients had retrieval in the Emergency Department and on the ward respectively while 19 patients needed examination under anaesthesia for extraction. The mean hospital stay was 19 (2-38) h. Associated psychosocial issues included depression, deliberate self-harm, illicit drug abuse, anxiety and alcoholism. There were no psychosocial problems identified in 15 patients. CONCLUSION There is a progressive rise in hospital presentation of impacted rectal foreign bodies with increasing use of different objects for sexual arousal. PMID:27830039

Increasing trend in retained rectal foreign bodies.

PubMed

Ayantunde, Abraham A; Unluer, Zynep

2016-10-27

To highlight the rising trend in hospital presentation of foreign bodies retained in the rectum over a 5-year period. Retrospective review of the cases of retained rectal foreign bodies between 2008 and 2012 was performed. Patients' clinical data and yearly case presentation with data relating to hospital episodes were collected. Data analysis was by SPSS Inc. Chicago, IL, United States. Twenty-five patients presented over a 5-year period with a mean age of 39 (17-62) years and M: F ratio of 2:1. A progressive rise in cases was noted from 2008 to 2012 with 3, 4, 4, 6, 8 recorded patients per year respectively. The majority of the impacted rectal objects were used for self-/partner-eroticism. The commonest retained foreign bodies were sex vibrators and dildos. Ninty-six percent of the patients required extraction while one passed spontaneously. Two and three patients had retrieval in the Emergency Department and on the ward respectively while 19 patients needed examination under anaesthesia for extraction. The mean hospital stay was 19 (2-38) h. Associated psychosocial issues included depression, deliberate self-harm, illicit drug abuse, anxiety and alcoholism. There were no psychosocial problems identified in 15 patients. There is a progressive rise in hospital presentation of impacted rectal foreign bodies with increasing use of different objects for sexual arousal.

Macrophages: development and tissue specialization.

PubMed

Varol, Chen; Mildner, Alexander; Jung, Steffen

2015-01-01

Macrophages are myeloid immune cells that are strategically positioned throughout the body tissues, where they ingest and degrade dead cells, debris, and foreign material and orchestrate inflammatory processes. Here we review two major recent paradigm shifts in our understanding of tissue macrophage biology. The first is the realization that most tissue-resident macrophages are established prenatally and maintained through adulthood by longevity and self-renewal. Their generation and maintenance are thus independent from ongoing hematopoiesis, although the cells can be complemented by adult monocyte-derived macrophages. Second, aside from being immune sentinels, tissue macrophages form integral components of their host tissue. This entails their specialization in response to local environmental cues to contribute to the development and specific function of their tissue of residence. Factors that govern tissue macrophage specialization are emerging. Moreover, tissue specialization is reflected in discrete gene expression profiles of macrophages, as well as epigenetic signatures reporting actual and potential enhancer usage.

Loss of autophagy enhances MIF/macrophage migration inhibitory factor release by macrophages.

PubMed

Lee, Jacinta P W; Foote, Andrew; Fan, Huapeng; Peral de Castro, Celia; Lang, Tali; Jones, Sarah A; Gavrilescu, Nichita; Mills, Kingston H G; Leech, Michelle; Morand, Eric F; Harris, James

2016-06-02

MIF (macrophage migration inhibitory factor [glycosylation-inhibiting factor]) is a pro-inflammatory cytokine expressed in multiple cells types, including macrophages. MIF plays a pathogenic role in a number of inflammatory diseases and has been linked to tumor progression in some cancers. Previous work has demonstrated that loss of autophagy in macrophages enhances secretion of IL1 family cytokines. Here, we demonstrate that loss of autophagy, by pharmacological inhibition or siRNA silencing of Atg5, enhances MIF secretion by monocytes and macrophages. We further demonstrate that this is dependent on mitochondrial reactive oxygen species (ROS). Induction of autophagy with MTOR inhibitors had no effect on MIF secretion, but amino acid starvation increased secretion. This was unaffected by Atg5 siRNA but was again dependent on mitochondrial ROS. Our data demonstrate that autophagic regulation of mitochondrial ROS plays a pivotal role in the regulation of inflammatory cytokine secretion in macrophages, with potential implications for the pathogenesis of inflammatory diseases and cancers.

Candida albicans Chitin Increases Arginase-1 Activity in Human Macrophages, with an Impact on Macrophage Antimicrobial Functions.

PubMed

Wagener, Jeanette; MacCallum, Donna M; Brown, Gordon D; Gow, Neil A R

2017-01-24

The opportunistic human fungal pathogen Candida albicans can cause a variety of diseases, ranging from superficial mucosal infections to life-threatening systemic infections. Phagocytic cells of the innate immune response, such as neutrophils and macrophages, are important first-line responders to an infection and generate reactive oxygen and nitrogen species as part of their protective antimicrobial response. During an infection, host cells generate nitric oxide through the enzyme inducible nitric oxide synthase (iNOS) to kill the invading pathogen. Inside the phagocyte, iNOS competes with the enzyme arginase-1 for a common substrate, the amino acid l-arginine. Several pathogenic species, including bacteria and parasitic protozoans, actively modulate the production of nitric oxide by inducing their own arginases or the host's arginase activity to prevent the conversion of l-arginine to nitric oxide. We report here that C. albicans blocks nitric oxide production in human-monocyte-derived macrophages by induction of host arginase activity. We further determined that purified chitin (a fungal cell wall polysaccharide) and increased chitin exposure at the fungal cell wall surface induces this host arginase activity. Blocking the C. albicans-induced arginase activity with the arginase-specific substrate inhibitor Nω-hydroxy-nor-arginine (nor-NOHA) or the chitinase inhibitor bisdionin F restored nitric oxide production and increased the efficiency of fungal killing. Moreover, we determined that C. albicans influences macrophage polarization from a classically activated phenotype toward an alternatively activated phenotype, thereby reducing antimicrobial functions and mediating fungal survival. Therefore, C. albicans modulates l-arginine metabolism in macrophages during an infection, potentiating its own survival. The availability and metabolism of amino acids are increasingly recognized as crucial regulators of immune functions. In acute infections, the conversion

Imaging Macrophage-associated Inflammation.

PubMed

Foss, Catherine A; Sanchez-Bautista, Julian; Jain, Sanjay K

2018-05-01

Macrophages belong to the mononuclear phagocyte system comprising closely related cells of bone marrow origin. Activated macrophages are critical in several diseases such as tuberculosis, sarcoidosis, Crohn's disease, and atherosclerosis. Noninvasive imaging techniques that can specifically image activated macrophages could therefore help in differentiating various forms of inflammatory diseases and to monitor therapeutic responses. Copyright © 2017. Published by Elsevier Inc.

Fluid-phase pinocytosis of LDL by macrophages: a novel target to reduce macrophage cholesterol accumulation in atherosclerotic lesions.

PubMed

Kruth, Howar S

2013-01-01

Circulating low-density lipoprotein (LDL) that enters the blood vessel wall is the main source of cholesterol that accumulates within atherosclerotic plaques. Much of the deposited cholesterol accumulates within plaque macrophages converting these macrophages into cholesterol-rich foamy looking cells. Cholesterol accumulation in macrophages contributes to cholesterol retention within the vessel wall, and promotes vessel wall inflammation and thrombogenicity. Thus, how macrophages accumulate cholesterol and become foam cells has been the subject of intense investigation. It is generally believed that macrophages accumulate cholesterol only through scavenger receptor-mediated uptake of modified LDL. However, an alternative mechanism for macrophage foam cell formation that does not depend on LDL modification or macrophage receptors has been elucidated. By this alternative mechanism, macrophages show receptor-independent uptake of unmodified native LDL that is mediated by fluid-phase pinocytosis. In receptor-independent, fluid-phase pinocytosis, macrophages take up LDL as part of the fluid that they ingest during micropinocytosis within small vesicles called micropinosomes, and by macropinocytosis within larger vacuoles called macropinosomes. This produces cholesterol accumulation in macrophages to levels characteristic of macrophage foam cells in atherosclerotic plaques. Fluid-phase pinocytosis of LDL is a plausible mechanism that can explain how macrophages accumulate cholesterol and become disease-causing foam cells. Fluid-phase pinocytosis of LDL is a relevant pathway to target for modulating macrophage cholesterol accumulation in atherosclerosis. Recent studies show that phosphoinositide 3-kinase (PI3K), liver X receptors (LXRs), the macrophage colony-stimulating factor (M-CSF) receptor, and protein kinase C (PKC) mediate macrophage macropinocytosis of LDL, and thus, these may be relevant targets to inhibit macrophage cholesterol accumulation in atherosclerosis.

Moderate restriction of macrophage-tropic human immunodeficiency virus type 1 by SAMHD1 in monocyte-derived macrophages.

PubMed

Taya, Kahoru; Nakayama, Emi E; Shioda, Tatsuo

2014-01-01

Macrophage-tropic human immunodeficiency virus type 1 (HIV-1) strains are able to grow to high titers in human monocyte-derived macrophages. However, it was recently reported that cellular protein SAMHD1 restricts HIV-1 replication in human cells of the myeloid lineage, including monocyte-derived macrophages. Here we show that degradation of SAMHD1 in monocyte-derived macrophages was associated with moderately enhanced growth of the macrophage-tropic HIV-1 strain. SAMHD1 degradation was induced by treating target macrophages with vesicular stomatitis virus glycoprotein-pseudotyped human immunodeficiency virus type 2 (HIV-2) particles containing viral protein X. For undifferentiated monocytes, HIV-2 particle treatment allowed undifferentiated monocytes to be fully permissive for productive infection by the macrophage-tropic HIV-1 strain. In contrast, untreated monocytes were totally resistant to HIV-1 replication. These results indicated that SAMHD1 moderately restricts even a macrophage-tropic HIV-1 strain in monocyte-derived macrophages, whereas the protein potently restricts HIV-1 replication in undifferentiated monocytes.

Modulation of Decidual Macrophage Polarization by Macrophage Colony-Stimulating Factor Derived from First-Trimester Decidual Cells

PubMed Central

Li, Min; Piao, Longzhu; Chen, Chie-Pein; Wu, Xianqing; Yeh, Chang-Ching; Masch, Rachel; Chang, Chi-Chang; Huang, S. Joseph

2017-01-01

During human pregnancy, immune tolerance of the fetal semiallograft occurs in the presence of abundant maternal leukocytes. At the implantation site, macrophages comprise approximately 20% of the leukocyte population and act as primary mediators of tissue remodeling. Decidual macrophages display a balance between anti-inflammatory and proinflammatory phenotypes. However, a shift to an M1 subtype is reported in preeclampsia. Granulocyte-macrophage colony-stimulating-factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF) are major differentiating factors that mediate M1 and M2 polarization, respectively. Previously, we observed the following: i) the preeclamptic decidua contains an excess of both macrophages and GM-CSF, ii) the preeclampsia-associated proinflammatory cytokines, IL-1β and tumor necrosis factor-α, markedly enhance GM-CSF and M-CSF expression in cultured leukocyte-free first-trimester decidual cells (FTDCs), iii) FTDC-secreted GM-CSF polarizes macrophages toward an M1 subtype. The microenvironment is a key determinant of macrophage phenotype. Thus, we examined proinflammatory stimulation of FTDC-secreted M-CSF and its role in macrophage development. Immunofluorescence staining demonstrated elevated M-CSF–positive decidual cell numbers in preeclamptic decidua. In FTDCs, IL-1β and tumor necrosis factor-α signal through the NF-κB pathway to induce M-CSF production, which does the following: i) enhances differentiation of and elevates CD163 expression in macrophages, ii) increases macrophage phagocytic capacity, and iii) inhibits signal-regulatory protein α expression by macrophages. These findings suggest that FTDC-secreted M-CSF modulates the decidual immune balance by inducing M2 macrophage polarization and phagocytic capacity in response to proinflammatory stimuli. PMID:26970370

M1 Macrophages but Not M2 Macrophages Are Characterized by Upregulation of CRP Expression via Activation of NFκB: a Possible Role for Ox-LDL in Macrophage Polarization.

PubMed

Kaplan, Marielle; Shur, Anna; Tendler, Yvgeny

2018-04-23

Arterial macrophages comprise a heterogeneous population: pro-inflammatory (M1) and anti-inflammatory (M2). Since C-reactive protein (CRP) is produced by macrophages in atherosclerotic lesions, understanding of CRP regulation in macrophages could be crucial to decipher inflammatory patterns in atherogenesis. We aimed to analyze CRP expression in M1/M2 macrophages and to question whether it involves NFκB signaling pathway. Furthermore, we questioned whether oxidative stress affect macrophage phenotype and modulate macrophage CRP expression. M1/M2 macrophage polarization was validated using THP-1 macrophages. CRP mRNA and protein expression were determined using real-time PCR and immunohistochemistry. Involvement of NFκB was determined by nuclear translocation of p50 subunit and the use of NFκB inhibitor. Involvement of oxidative stress in macrophage phenotypes induction was studied using oxidized-LDL (Ox-LDL) and antioxidants. M1 macrophages were characterized by elevated CRP mRNA expression (by 67%), CRP protein levels (by 108%), and upregulation of NFκB activation compared to control, but these features were not shared by M2 macrophages. Macrophages incubation with Ox-LDL led to a moderate M1 phenotype combined with a M2 phenotype, correlated with increased CRP mRNA expression. Antioxidants inhibited by up to 86% IL6 expression but did not significantly affect IL10 secretion. Antioxidants significantly inhibited CRP expression in M1 macrophages, but not in M2 macrophages. Elevated expression of CRP was characteristic of M1 macrophages rather than M2 through NFκB activation. Oxidative stress could be one of the endogenous triggers for macrophage activation to a mixed M1 and M2 phenotype, in association with increased expression of CRP.

Regulation of Alternative Macrophage Activation in the Liver following Acetaminophen Intoxication by Stem Cell-Derived Tyrosine Kinase

PubMed Central

Gardner, Carol R.; Hankey, Pamela; Mishin, Vladimir; Francis, Mary; Yu, Shan; Laskin, Jeffrey D.; Laskin, Debra L.

2012-01-01

Stem cell-derived tyrosine kinase (STK) is a transmembrane receptor reported to play a role in macrophage switching from a classically activated/proinflammatory phenotype to an alternatively activated/wound repair phenotype. In the present studies, STK−/− mice were used to assess the role of STK in acetaminophen-induced hepatotoxicity as evidence suggests that the pathogenic process involves both of these macrophage subpopulations. In wild type mice, centrilobular hepatic necrosis and increases in serum transaminase levels were observed within 6 hr of acetaminophen administration (300 mg/kg, i.p.). Loss of STK resulted in a significant increase in sensitivity of mice to the hepatotoxic effects of acetaminophen and increased mortality, effects independent of its metabolism. This was associated with reduced levels of hepatic glutathione, rapid upregulation of inducible nitric oxide synthase, and prolonged induction of heme oxygenase-1, suggesting excessive oxidative stress in STK−/− mice. F4/80, a marker of mature macrophages, was highly expressed on subpopulations of Kupffer cells in livers of wild type, but not STK −/− mice. Whereas F4/80+ macrophages rapidly declined in the livers of wild type mice following acetaminophen intoxication, they increased in STK−/− mice. In wild type mice hepatic expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-12, products of classically activated macrophages, increased after acetaminophen administration. Monocyte chemotactic protein-1 (MCP-1) and its receptor, CCR2, as well as IL-10, mediators involved in recruiting and activating anti-inflammatory/wound repair macrophages, also increased in wild type mice after acetaminophen. Loss of STK blunted the effects of acetaminophen on expression of TNFα, IL-1β, IL-12, MCP-1 and CCR2, while expression of IL-10 increased. Hepatic expression of CX3CL1, and its receptor, CX3CR1 also increased in STK−/− mice treated with acetaminophen. These data

Mesenchymal stem cells ameliorate rhabdomyolysis-induced acute kidney injury via the activation of M2 macrophages

PubMed Central

2014-01-01

Introduction The mortality of rhabdomyolysis-induced acute kidney injury (AKI) is still high, as there is no effective therapy. It has been shown that bone marrow-derived mesenchymal stem cells (MSCs) can induce M2 macrophages, which mediate MSC protection in other experimental inflammation-related organ injury. This study was designed to investigate the protective effects of macrophage activation in MSC therapy of rhabdomyolysis-induced AKI. Methods MSCs were injected into glycerol-induced rhabdomyolysis mice. Renal injury was evaluated using the serum creatinine, urea nitrogen, renal pathology and acute tubular necrosis score. The distribution of MSCs was detected using two-photon fluorescence confocal imaging. Immunofluorescence of anti-F4/80 and anti-CD206 was performed to determine macrophages and M2 macrophages in the tissues of the kidney, and M2 macrophage infiltration was also evaluated using western blotting analyses. After depletion of macrophages using clodronate liposomes at the phase of kidney repair, renal injury was re-evaluated. RAW 264.7 macrophages were incubated with lipopolysaccharide and co-cultured with MSCs and subsequently visualised using immunofluorescence staining and flow cytometry analysis. Finally, disparate phenotype macrophages, including normal macrophages (M0), lipopolysaccharide-stimulated macrophages (M1), and MSC-co-cultured macrophages (M2), were infused into mice with AKI, which were pre-treated with liposomal clodronate. Results In vivo infusion of MSCs protected AKI mice from renal function impairment and severe tubular injury, which was accompanied by a time-dependent increase in CD206-positive M2 macrophage infiltration. In addition, depleting macrophages with clodronate delayed restoration of AKI. In vitro, macrophages co-cultured with MSCs acquired an anti-inflammatory M2 phenotype, which was characterised by an increased expression of CD206 and the secretory cytokine interleukin (IL)-10. The concentrations of IL-10, IL

Soluble human leukocyte antigen G5 polarizes differentiation of macrophages toward a decidual macrophage-like phenotype.

PubMed

Lee, Cheuk-Lun; Guo, YiFan; So, Kam-Hei; Vijayan, Madhavi; Guo, Yue; Wong, Vera H H; Yao, YuanQing; Lee, Kai-Fai; Chiu, Philip C N; Yeung, William S B

2015-10-01

What are the actions of soluble human leukocyte antigen G5 (sHLAG5) on macrophage differentiation? sHLAG5 polarizes the differentiation of macrophages toward a decidual macrophage-like phenotype, which could regulate fetomaternal tolerance and placental development. sHLAG5 is a full-length soluble isoform of human leukocyte antigen implicated in immune tolerance during pregnancy. Low or undetectable circulating level of sHLAG5 in first trimester of pregnancy is associated with pregnancy complications such as pre-eclampsia and spontaneous abortion. Decidual macrophages are located in close proximity to invasive trophoblasts, and are involved in regulating fetomaternal tolerance and placental development. Human peripheral blood monocytes were differentiated into macrophages by treatment with granulocyte macrophage colony-stimulating factor in the presence or absence of recombinant sHLAG5 during the differentiation process. The phenotypes and the biological activities of the resulting macrophages were compared. Recombinant sHLAG5 was produced in Escherichia coli BL21 and the protein identity was verified by tandem mass spectrometry. The expression of macrophage markers were analyzed by flow cytometry and quantitative PCR. Phagocytosis was determined by flow cytometry. Indoleamine 2,3-dioxygenase 1 expression and activity were measured by western blot analysis and kynurenine assay, respectively. Cell proliferation and cell cycling were determined by fluorometric cell proliferation assay and flow cytometry, respectively. Cytokine secretion was determined by cytokine array and ELISA kits. Intracellular cytokine expression was measured by flow cytometry. Cell invasion and migration were determined by trans-well invasion and migration assay, respectively. sHLAG5 drove the differentiation of macrophages with 'immuno-modulatory' characteristics, including reduced expression of M1 macrophage marker CD86 and increased expression of M2 macrophage marker CD163. sHLAG5-polarized

Fatty acid 16:4(n-3) stimulates a GPR120-induced signaling cascade in splenic macrophages to promote chemotherapy resistance

PubMed Central

Houthuijzen, Julia M.; Oosterom, Ilse; Hudson, Brian D.; Hirasawa, Akira; Daenen, Laura G. M.; McLean, Chelsea M.; Hansen, Steffen V. F.; van Jaarsveld, Marijn T. M.; Peeper, Daniel S.; Jafari Sadatmand, Sahar; Roodhart, Jeanine M. L.; van de Lest, Chris H. A.; Ulven, Trond; Ishihara, Kenji; Milligan, Graeme; Voest, Emile E.

2017-01-01

Although chemotherapy is designed to eradicate tumor cells, it also has significant effects on normal tissues. The platinum-induced fatty acid 16:4(n-3) (hexadeca-4,7,10,13-tetraenoic acid) induces systemic resistance to a broad range of DNA-damaging chemotherapeutics. We show that 16:4(n-3) exerts its effect by activating splenic F4/80+/CD11blow macrophages, which results in production of chemoprotective lysophosphatidylcholines (LPCs). Pharmacologic studies, together with analysis of expression patterns, identified GPR120 on F4/80+/CD11blow macrophages as the relevant receptor for 16:4(n-3). Studies that used splenocytes from GPR120-deficient mice have confirmed this conclusion. Activation of the 16:4(n-3)-GPR120 axis led to enhanced cPLA2 activity in these splenic macrophages and secretion of the resistance-inducing lipid mediator, lysophosphatidylcholine(24:1). These studies identify a novel and unexpected function for GPR120 and suggest that antagonists of this receptor might be effective agents to limit development of chemotherapy resistance.—Houthuijzen, J. M., Oosterom, I., Hudson, B. D., Hirasawa, A., Daenen, L. G. M., McLean, C. M., Hansen, S. V. F., van Jaarsveld, M. T. M., Peeper, D. S., Jafari Sadatmand, S., Roodhart, J. M. L., van de Lest, C. H. A., Ulven, T., Ishihara, K., Milligan, G., Voest, E. E. Fatty acid 16:4(n-3) stimulates a GPR120-induced signaling cascade in splenic macrophages to promote chemotherapy resistance. PMID:28183801

Systemic anti-TNFalpha treatment restores diabetes-impaired skin repair in ob/ob mice by inactivation of macrophages.

PubMed

Goren, Itamar; Müller, Elke; Schiefelbein, Dana; Christen, Urs; Pfeilschifter, Josef; Mühl, Heiko; Frank, Stefan

2007-09-01

To date, diabetes-associated skin ulcerations represent a therapeutic problem of clinical importance. The insulin-resistant type II diabetic phenotype is functionally connected to obesity in rodent models of metabolic syndrome through the release of inflammatory mediators from adipose tissue. Here, we used the impaired wound-healing process in obese/obese (ob/ob) mice to investigate the impact of obesity-mediated systemic inflammation on cutaneous wound-healing processes. Systemic administration of neutralizing monoclonal antibodies against tumor necrosis factor (TNF)alpha (V1q) or monocyte/macrophage-expressed EGF-like module-containing mucin-like hormone receptor-like (Emr)-1 (F4/80) into wounded ob/ob mice at the end of acute wound inflammation initiated a rapid and complete neo-epidermal coverage of impaired wound tissue in the presence of a persisting diabetic phenotype. Wound closure in antibody-treated mice was paralleled by a marked attenuation of wound inflammation. Remarkably, anti-TNFalpha- and anti-F4/80-treated mice exhibited a strong reduction in circulating monocytic cells and reduced numbers of viable macrophages at the wound site. Our data provide strong evidence that anti-TNFalpha therapy, widely used in chronic inflammatory diseases in humans, might also exert effects by targeting "activated" TNFalpha-expressing macrophage subsets, and that inactivation or depletion of misbehaving macrophages from impaired wounds might be a novel therapeutic clue to improve healing of skin ulcers.

Human Induced Pluripotent Stem Cell-Derived Macrophages for Unraveling Human Macrophage Biology.

PubMed

Zhang, Hanrui; Reilly, Muredach P

2017-11-01

Despite a substantial appreciation for the critical role of macrophages in cardiometabolic diseases, understanding of human macrophage biology has been hampered by the lack of reliable and scalable models for cellular and genetic studies. Human induced pluripotent stem cell (iPSC)-derived macrophages (IPSDM), as an unlimited source of subject genotype-specific cells, will undoubtedly play an important role in advancing our understanding of the role of macrophages in human diseases. In this review, we summarize current literature in the differentiation and characterization of IPSDM at phenotypic, functional, and transcriptomic levels. We emphasize the progress in differentiating iPSC to tissue resident macrophages, and in understanding the ontogeny of in vitro differentiated IPSDM that resembles primitive hematopoiesis, rather than adult definitive hematopoiesis. We review the application of IPSDM in modeling both Mendelian genetic disorders and host-pathogen interactions. Finally, we highlighted the potential areas of research using IPSDM in functional validation of coronary artery disease loci in genome-wide association studies, functional genomic analyses, drug testing, and cell therapeutics in cardiovascular diseases. © 2017 American Heart Association, Inc.

Macrophages: Their Emerging Roles in Bone

PubMed Central

Sinder, Benjamin P; Pettit, Allison R; McCauley, Laurie K

2016-01-01

Macrophages are present in nearly all tissues and are critical for development, homeostasis, and regeneration. Resident tissue macrophages of bone, termed osteal macrophages, are recently classified myeloid cells that are distinct from osteoclasts. Osteal macrophages are located immediately adjacent to osteoblasts, regulate bone formation, and play diverse roles in skeletal homeostasis. Genetic or pharmacological modulation of macrophages in vivo results in significant bone phenotypes, and these phenotypes depend on which macrophage subsets are altered. Macrophages are also key mediators of osseous wound healing and fracture repair, with distinct roles at various stages of the repair process. A central function of macrophages is their phagocytic ability. Each day, billions of cells die in the body and efferocytosis (phagocytosis of apoptotic cells) is a critical process in both clearing dead cells and recruitment of replacement progenitor cells to maintain homeostasis. Recent data suggest a role for efferocytosis in bone biology and these new mechanisms are outlined. Finally, although macrophages have an established role in primary tumors, emerging evidence suggests that macrophages in bone support cancers which preferentially metastasize to the skeleton. Collectively, this developing area of osteoimmunology raises new questions and promises to provide novel insights into pathophysiologic conditions as well as therapeutic and regenerative approaches vital for skeletal health. PMID:26531055

Cystatin B and HIV regulate the STAT-1 signaling circuit in HIV-infected and INF-β-treated human macrophages.

PubMed

Rivera, L E; Kraiselburd, E; Meléndez, L M

2016-10-01

Cystatin B is a cysteine protease inhibitor that induces HIV replication in monocyte-derived macrophages (MDM). This protein interacts with signal transducer and activator of transcription (STAT-1) factor and inhibits the interferon (IFN-β) response in Vero cells by preventing STAT-1 translocation to the nucleus. Cystatin B also decreases the levels of tyrosine-phosphorylated STAT-1 (STAT-1PY). However, the mechanisms of cystatin B regulation on STAT-1 phosphorylation in MDM are unknown. We hypothesized that cystatin B inhibits IFN-β antiviral responses and induces HIV replication in macrophage reservoirs through the inhibition of STAT-1 phosphorylation. Macrophages were transfected with cystatin B siRNA prior to interferon-β treatment or infected with HIV-ADA to determine the effect of cystatin B modulation in STAT-1 localization and activation using immunofluorescence and proximity ligation assays. Cystatin B decreased STAT-1PY and its transportation to the nucleus, while HIV infection retained unphosphorylated STAT (USTAT-1) in the nucleus avoiding its exit to the cytoplasm for eventual phosphorylation. In IFN-β-treated MDM, cystatin B inhibited the nuclear translocation of both, USTAT-1 and STAT-1PY. These results demonstrate that cystatin B interferes with the STAT-1 signaling and IFN-β-antiviral responses perpetuating HIV in macrophage reservoirs.

Proliferating macrophages prevail in atherosclerosis.

PubMed

Randolph, Gwendalyn J

2013-09-01

Macrophages accumulate in atherosclerotic lesions during the inflammation that is part of atherosclerosis development and progression. A new study in mice indicates that the accumulation of macrophages in atherosclerotic plaques depends on local macrophage proliferation rather than the recruitment of circulating monocytes.

Origin and Functions of Tissue Macrophages

PubMed Central

Epelman, Slava; Lavine, Kory J.; Randolph, Gwendalyn J.

2015-01-01

Macrophages are distributed in tissues throughout the body and contribute to both homeostasis and disease. Recently, it has become evident that most adult tissue macrophages originate during embryonic development and not from circulating monocytes. Each tissue has its own composition of embryonically derived and adult-derived macrophages, but it is unclear whether macrophages of distinct origins are functionally interchangeable or have unique roles at steady state. This new understanding also prompts reconsideration of the function of circulating monocytes. Classical Ly6chi monocytes patrol the extravascular space in resting organs, and Ly6clo nonclassical monocytes patrol the vasculature. Inflammation triggers monocytes to differentiate into macrophages, but whether resident and newly recruited macrophages possess similar functions during inflammation is unclear. Here, we define the tools used for identifying the complex origin of tissue macrophages and discuss the relative contributions of tissue niche versus ontological origin to the regulation of macrophage functions during steady state and inflammation. PMID:25035951

Structurally distinct membrane nanotubes between human macrophages support long-distance vesicular traffic or surfing of bacteria.

PubMed

Onfelt, Björn; Nedvetzki, Shlomo; Benninger, Richard K P; Purbhoo, Marco A; Sowinski, Stefanie; Hume, Alistair N; Seabra, Miguel C; Neil, Mark A A; French, Paul M W; Davis, Daniel M

2006-12-15

We report that two classes of membrane nanotubes between human monocyte-derived macrophages can be distinguished by their cytoskeletal structure and their functional properties. Thin membrane nanotubes contained only F-actin, whereas thicker nanotubes, i.e., those > approximately 0.7 microm in diameter, contained both F-actin and microtubules. Bacteria could be trapped and surf along thin, but not thick, membrane nanotubes toward connected macrophage cell bodies. Once at the cell body, bacteria could then be phagocytosed. The movement of bacteria is aided by a constitutive flow of the nanotube surface because streptavidin-coated beads were similarly able to traffic along nanotubes between surface-biotinylated macrophages. Mitochondria and intracellular vesicles, including late endosomes and lysosomes, could be detected within thick, but not thin, membrane nanotubes. Analysis from kymographs demonstrated that vesicles moved in a stepwise, bidirectional manner at approximately 1 microm/s, consistent with their traffic being mediated by the microtubules found only in thick nanotubes. Vesicular traffic in thick nanotubes and surfing of beads along thin nanotubes were both stopped upon the addition of azide, demonstrating that both processes require ATP. However, microtubule destabilizing agents colchicine or nocodazole abrogated vesicular transport but not the flow of the nanotube surface, confirming that distinct cytoskeletal structures of nanotubes give rise to different functional properties. Thus, membrane nanotubes between macrophages are more complex than unvarying ubiquitous membrane tethers and facilitate several means for distal interactions between immune cells.

Inhibition of Neddylation Represses Lipopolysaccharide-induced Proinflammatory Cytokine Production in Macrophage Cells

PubMed Central

Chang, Fang-Mei; Reyna, Sara M.; Granados, Jose C.; Wei, Sung-Jen; Innis-Whitehouse, Wendy; Maffi, Shivani K.; Rodriguez, Edward; Slaga, Thomas J.; Short, John D.

2012-01-01

Cullin-RING E3 ligases (CRLs) are a class of ubiquitin ligases that control the proteasomal degradation of numerous target proteins, including IκB, and the activity of these CRLs are positively regulated by conjugation of a Nedd8 polypeptide onto Cullin proteins in a process called neddylation. CRL-mediated degradation of IκB, which normally interacts with and retains NF-κB in the cytoplasm, permits nuclear translocation and transactivation of the NF-κB transcription factor. Neddylation occurs through a multistep enzymatic process involving Nedd8 activating enzymes, and recent studies have shown that the pharmacological agent, MLN4924, can potently inhibit Nedd8 activating enzymes, thereby preventing neddylation of Cullin proteins and preventing the degradation of CRL target proteins. In macrophages, regulation of NF-κB signaling functions as a primary pathway by which infectious agents such as lipopolysaccharides (LPSs) cause the up-regulation of proinflammatory cytokines. Here we have analyzed the effects of MLN4924, and compared the effects of MLN4924 with a known anti-inflammatory agent (dexamethasone), on certain proinflammatory cytokines (TNF-α and IL-6) and the NF-κB signaling pathway in LPS-stimulated macrophages. We also used siRNA to block neddylation to assess the role of this molecular process during LPS-induced cytokine responsiveness. Our results demonstrate that blocking neddylation, either pharmacologically or using siRNA, abrogates the increase in certain proinflammatory cytokines secreted from macrophages in response to LPS. In addition, we have shown that MLN4924 and dexamethasone inhibit LPS-induced cytokine up-regulation at the transcriptional level, albeit through different molecular mechanisms. Thus, neddylation represents a novel molecular process in macrophages that can be targeted to prevent and/or treat the LPS-induced up-regulation of proinflammatory cytokines and the disease processes associated with their up-regulation. PMID

NFAT5-Regulated Macrophage Polarization Supports the Proinflammatory Function of Macrophages and T Lymphocytes.

PubMed

Tellechea, Mónica; Buxadé, Maria; Tejedor, Sonia; Aramburu, Jose; López-Rodríguez, Cristina

2018-01-01

Macrophages are exquisite sensors of tissue homeostasis that can rapidly switch between pro- and anti-inflammatory or regulatory modes to respond to perturbations in their microenvironment. This functional plasticity involves a precise orchestration of gene expression patterns whose transcriptional regulators have not been fully characterized. We had previously identified the transcription factor NFAT5 as an activator of TLR-induced responses, and in this study we explore its contribution to macrophage functions in different polarization settings. We found that both in classically and alternatively polarized macrophages, NFAT5 enhanced functions associated with a proinflammatory profile such as bactericidal capacity and the ability to promote Th1 polarization over Th2 responses. In this regard, NFAT5 upregulated the Th1-stimulatory cytokine IL-12 in classically activated macrophages, whereas in alternatively polarized ones it enhanced the expression of the pro-Th1 mediators Fizz-1 and arginase 1, indicating that it could promote proinflammatory readiness by regulating independent genes in differently polarized macrophages. Finally, adoptive transfer assays in vivo revealed a reduced antitumor capacity in NFAT5-deficient macrophages against syngeneic Lewis lung carcinoma and ID8 ovarian carcinoma cells, a defect that in the ID8 model was associated with a reduced accumulation of effector CD8 T cells at the tumor site. Altogether, detailed analysis of the effect of NFAT5 in pro- and anti-inflammatory macrophages uncovered its ability to regulate distinct genes under both polarization modes and revealed its predominant role in promoting proinflammatory macrophage functions. Copyright © 2017 by The American Association of Immunologists, Inc.

Suppression of inflammation-associated factors by indole-3-carbinol in mice fed high-fat diets and in isolated, co-cultured macrophages and adipocytes.

PubMed

Chang, H-P; Wang, M-L; Hsu, C-Y; Liu, M-E; Chan, M-H; Chen, Y-H

2011-12-01

This study investigated the effects of indole-3-carbinol (I3C), a compound from cruciferous vegetables, on various parameters related to obesity, in particular, the parameters of infiltration by macrophages and of inflammatory cytokines expressed during the co-culture of adipocytes and macrophages. Male C57BL/6 mice were fed with a control diet (C group), high-fat diet (HF group) and HF+5 mg kg(-1) I3C (HFI group). The I3C was intraperitoneally injected (HFI group) for 12 weeks. Epididymal adipose tissue (AT) was collected and stained for F4/80, a marker of macrophages. The immunohistochemical staining for F4/80 indicated a greater presence of macrophages in the HF group than in AT from the control and HFI groups. Furthermore, I3C treatment, in an in vitro cell culture system, decreased expression of inducible nitric oxide synthase (iNOS), decreased nitrite content and enhanced expression of peroxisome proliferator-activated receptor (PPAR-γ). Moreover, in vitro cell culture studies revealed that I3C inhibited intracellular lipid accumulation in hypertrophied adipocytes. In macrophage and primary adipocyte co-culture, I3C inhibited expression of interleukin-6 (IL-6). In vivo treatment with I3C reduced the infiltration of macrophages in AT, and in vitro addition of I3C to co-cultured macrophages and adipocytes reduced nitrite production and IL-6 expression. With cultures of adipocytes only, I3C inhibited accumulation of intracellular lipid, either by disrupting differentiation, or by directly inhibiting triglyceride synthesis.

NERVA turbopump bearing retainer fabrication on nonmetallic retainer

NASA Technical Reports Server (NTRS)

Accinelli, J. B.

1972-01-01

The need for a low-wear, lightweight, high strength bearing retainer material with a radiation degradation threshold of 10 to the 9th power rads (C) prompted development of nonmetallic reinforced polymers of the following types: (1) polybenzimidazole, (2) polyimide, and (3) polyquinoxaline. Retainers were machined from tubular laminates (billets), including reinforcement by either glass or graphite fabric or filament. Fabrication of billets involves hot preimpregnation of the reinforcement fabric or filament with polymer followed by wrapping this prepreg over a heated mandrel to form a tube with the required thickness and length.

Granulocyte-macrophage and macrophage colony-stimulating factors differentially regulate alpha v integrin expression on cultured human macrophages.

PubMed

De Nichilo, M O; Burns, G F

1993-03-15

The colony-stimulating factors (CSFs) greatly influence mature macrophage function in vitro: macrophage (M)-CSF induces maturation of monocytes and enhances differentiated cell function; granulocyte-macrophage (GM)-CSF stimulates a variety of antimicrobial functions. In vivo M-CSF is thought to promote differentiation, and GM-CSF is thought to potentiate the inflammatory response. One mechanism by which these differential effects may be achieved is through the receptor-mediated interaction of macrophages with their extracellular matrix. Here we show that M-CSF induces specifically the expression of the alpha v beta 5 integrin receptor, whereas GM-CSF rapidly induces mRNA and surface expression of the alpha v beta 3 integrin. The M-CSF-treated cells acquire a flattened epitheloid phenotype, and on vitronectin the alpha v beta 5 is located in adhesion plaques. These cells do not bind collagen or laminin. In contrast, cells treated with GM-CSF adopt an elongated phenotype on a number of substrates, including collagen and laminin, and express alpha v beta 3 at the leading edge of cells on vitronectin. These results suggest that a primary means by which the CSFs exert their individual effects on mature cells may be through regulating integrin expression.

Scavenger receptor B1 facilitates macrophage uptake of silver nanoparticles and cellular activation

NASA Astrophysics Data System (ADS)

Aldossari, Abdullah A.; Shannahan, Jonathan H.; Podila, Ramakrishna; Brown, Jared M.

2015-07-01

Due to increased use of silver nanoparticles (AgNPs) for their antimicrobial activity, concerns have risen regarding potential adverse human health effects. Scavenger receptor B1 (SR-B1), a major receptor for high-density lipoprotein (HDL), is expressed by macrophages and has also been reported to play a role in recognition of negatively charged particles. We, therefore, hypothesized that SR-B1 mediates macrophage uptake of AgNPs and inflammatory activation. To test this hypothesis, we exposed a mouse macrophage cell line RAW264.7 (RAW) and bone marrow-derived macrophages (BMDM) to 20 nm citrate-suspended AgNPs. To verify the role of the SR-B1 receptor, we utilized a SR-B1 inhibitor (Blt2). In vitro studies demonstrated uptake of AgNPs and HDL-coated AgNPs by macrophages which were significantly reduced following pretreatment with Blt2. Inflammatory cytokine arrays revealed that macrophages exposed to AgNPs up-regulated expression of Tnf- α, Oncostatin m (OSM), Ccl4, Il17f, Ccl7, and Ccl2, whereas Il16 was found to be down-regulated. Macrophage activation was observed following AgNP and HDL-coated AgNP exposure as measured by OSM protein production and increased surface expression of CD86. These markers of activation were reduced with Blt2 pretreatment. The in vitro findings were confirmed in vivo through pulmonary instillation of AgNPs in mice. Pulmonary instillation of AgNPs resulted in a recruitment of inflammatory cells that were reduced in SR-B1-deficient mice or following Blt2 pretreatment. This study suggests that SR-B1 plays a major role in cellular recognition of AgNPs and the induction of cell responses that could contribute to inflammation caused by AgNP exposure.

miR-126-5p by direct targeting of JNK-interacting protein-2 (JIP-2) plays a key role in Theileria-infected macrophage virulence

PubMed Central

Ansari, Hifzur Rahman; Tajeri, Shahin; Latre De Late, Perle; Langsley, Gordon

2018-01-01

Theileria annulata is an apicomplexan parasite that infects and transforms bovine macrophages that disseminate throughout the animal causing a leukaemia-like disease called tropical theileriosis. Using deep RNAseq of T. annulata-infected B cells and macrophages we identify a set of microRNAs induced by infection, whose expression diminishes upon loss of the hyper-disseminating phenotype of virulent transformed macrophages. We describe how infection-induced upregulation of miR-126-5p ablates JIP-2 expression to release cytosolic JNK to translocate to the nucleus and trans-activate AP-1-driven transcription of mmp9 to promote tumour dissemination. In non-disseminating attenuated macrophages miR-126-5p levels drop, JIP-2 levels increase, JNK1 is retained in the cytosol leading to decreased c-Jun phosphorylation and dampened AP-1-driven mmp9 transcription. We show that variation in miR-126-5p levels depends on the tyrosine phosphorylation status of AGO2 that is regulated by Grb2-recruitment of PTP1B. In attenuated macrophages Grb2 levels drop resulting in less PTP1B recruitment, greater AGO2 phosphorylation, less miR-126-5p associated with AGO2 and a consequent rise in JIP-2 levels. Changes in miR-126-5p levels therefore, underpin both the virulent hyper-dissemination and the attenuated dissemination of T. annulata-infected macrophages. PMID:29570727

Adipocyte fetuin-A contributes to macrophage migration into adipose tissue and polarization of macrophages.

PubMed

Chatterjee, Priyajit; Seal, Soma; Mukherjee, Sandip; Kundu, Rakesh; Mukherjee, Sutapa; Ray, Sukanta; Mukhopadhyay, Satinath; Majumdar, Subeer S; Bhattacharya, Samir

2013-09-27

Macrophage infiltration into adipose tissue during obesity and their phenotypic conversion from anti-inflammatory M2 to proinflammatory M1 subtype significantly contributes to develop a link between inflammation and insulin resistance; signaling molecule(s) for these events, however, remains poorly understood. We demonstrate here that excess lipid in the adipose tissue environment may trigger one such signal. Adipose tissue from obese diabetic db/db mice, high fat diet-fed mice, and obese diabetic patients showed significantly elevated fetuin-A (FetA) levels in respect to their controls; partially hepatectomized high fat diet mice did not show noticeable alteration, indicating adipose tissue to be the source of this alteration. In adipocytes, fatty acid induces FetA gene and protein expressions, resulting in its copious release. We found that FetA could act as a chemoattractant for macrophages. To simulate lipid-induced inflammatory conditions when proinflammatory adipose tissue and macrophages create a niche of an altered microenvironment, we set up a transculture system of macrophages and adipocytes; the addition of fatty acid to adipocytes released FetA into the medium, which polarized M2 macrophages to M1. This was further confirmed by direct FetA addition to macrophages. Taken together, lipid-induced FetA from adipocytes is an efficient chemokine for macrophage migration and polarization. These findings open a new dimension for understanding obesity-induced inflammation.

Macrophages and cellular immunity in Drosophila melanogaster

PubMed Central

Gold, Katrina S.; Brückner, Katja

2016-01-01

The invertebrate Drosophila melanogaster has been a powerful model for understanding blood cell development and immunity. Drosophila is a holometabolous insect, which transitions through a series of life stages from embryo, larva and pupa to adulthood. In spite of this, remarkable parallels exist between Drosophila and vertebrate macrophages, both in terms of development and function. More than 90% of Drosophila blood cells (hemocytes) are macrophages (plasmatocytes), making this highly tractable genetic system attractive for studying a variety of questions in macrophage biology. In vertebrates, recent findings revealed that macrophages have two independent origins: self-renewing macrophages, which reside and proliferate in local microenvironments in a variety of tissues, and macrophages of the monocyte lineage, which derive from hematopoietic stem or progenitor cells. Like vertebrates, Drosophila possesses two macrophage lineages with a conserved dual ontogeny. These parallels allow us to take advantage of the Drosophila model when investigating macrophage lineage specification, maintenance and amplification, and the induction of macrophages and their progenitors by local microenvironments and systemic cues. Beyond macrophage development, Drosophila further serves as a paradigm for understanding the mechanisms underlying macrophage function and cellular immunity in infection, tissue homeostasis and cancer, throughout development and adult life. PMID:27117654

Native low-density lipoprotein uptake by macrophage colony-stimulating factor-differentiated human macrophages is mediated by macropinocytosis and micropinocytosis.

PubMed

Anzinger, Joshua J; Chang, Janet; Xu, Qing; Buono, Chiara; Li, Yifu; Leyva, Francisco J; Park, Bum-Chan; Greene, Lois E; Kruth, Howard S

2010-10-01

To examine the pinocytotic pathways mediating native low-density lipoprotein (LDL) uptake by human macrophage colony-stimulating factor-differentiated macrophages (the predominant macrophage phenotype in human atherosclerotic plaques). We identified the kinase inhibitor SU6656 and the Rho GTPase inhibitor toxin B as inhibitors of macrophage fluid-phase pinocytosis of LDL. Assessment of macropinocytosis by time-lapse microscopy revealed that both drugs almost completely inhibited macropinocytosis, although LDL uptake and cholesterol accumulation by macrophages were only partially inhibited (approximately 40%) by these agents. Therefore, we investigated the role of micropinocytosis in mediating LDL uptake in macrophages and identified bafilomycin A1 as an additional partial inhibitor (approximately 40%) of macrophage LDL uptake that targeted micropinocytosis. When macrophages were incubated with both bafilomycin A1 and SU6656, inhibition of LDL uptake was additive (reaching 80%), showing that these inhibitors target different pathways. Microscopic analysis of fluid-phase uptake pathways in these macrophages confirmed that LDL uptake occurs through both macropinocytosis and micropinocytosis. Our findings show that human macrophage colony-stimulating factor-differentiated macrophages take up native LDL by macropinocytosis and micropinocytosis, underscoring the importance of both pathways in mediating LDL uptake by these cells.

Avian macrophage: effector functions in health and disease.

PubMed

Qureshi, M A; Heggen, C L; Hussain, I

2000-01-01

Monocytes-macrophages, cells belonging to the mononuclear phagocytic system, are considered as the first line of immunological defense. Being mobile scavenger cells, macrophages participate in innate immunity by serving as phagocytic cells. These cells arise in the bone marrow and subsequently enter the blood circulation as blood monocytes. Upon migration to various tissues, monocytes mature and differentiate into tissue macrophages. Macrophages then initiate the 'acquired' immune response in their capacity as antigen processing and presenting cells. While responding to their tissue microenvironment or exogenous antigenic challenge, macrophages may secrete several immunoregulatory cytokines or metabolites. Being the first line of immunological defense, macrophages therefore represent an important step during interaction with infectious agents. The outcome of the macrophage-pathogen interaction depends upon several factors including the stage of macrophage activation, the nature of the infectious agent, the level of genetic control on macrophage function as well as environmental and nutritional factors that may modulate macrophage activation and functions. Research in avian macrophages has lagged behind that in mammals. This has been largely due to the lack of harvestable resident macrophages from the chicken peritoneal cavity. However, the development of elicitation protocols to harvest inflammatory abdominal macrophages and the availability of transformed chicken macrophage cell lines, has enabled researchers to address several questions related to chicken macrophage biology and function in health and disease. In this manuscript the basic profiles of several macrophage effector functions are described. In addition, the interaction of macrophages with various pathogens as well as the effect of genetic and environmental factors on macrophage functional modulation is described.

Granulocyte-macrophage colony-stimulating factor primes interleukin-13 production by macrophages via protease-activated receptor-2.

PubMed

Aoki, Manabu; Yamaguchi, Rui; Yamamoto, Takatoshi; Ishimaru, Yasuji; Ono, Tomomichi; Sakamoto, Arisa; Narahara, Shinji; Sugiuchi, Hiroyuki; Hirose, Eiji; Yamaguchi, Yasuo

2015-04-01

Chronic inflammation is often linked to the presence of type 2-polarized macrophages, which are induced by the T helper type 2 cytokines interleukin-4 and interleukin-13 (IL-13). IL-13 is a key mediator of tissue fibrosis caused by T helper type 2-based inflammation. Human neutrophil elastase (HNE) plays a pivotal role in the pathogenesis of pulmonary fibrosis. This study investigated the priming effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on IL-13 expression by macrophages stimulated with HNE. Adherent macrophages were obtained from primary cultures of human mononuclear cells. Expression of IL-13 mRNA and protein by GM-CSF-dependent macrophages was investigated after stimulation with HNE, using the polymerase chain reaction and enzyme-linked immunosorbent assay. GM-CSF had a priming effect on IL-13 mRNA and protein expression by macrophages stimulated with HNE, while this effect was not observed for various other cytokines. GM-CSF-dependent macrophages showed a significant increase in the expression of protease activated receptor-2 (PAR-2) mRNA and protein. The response of IL-13 mRNA to HNE was significantly decreased by pretreatment with alpha1-antitrypsin, a PAR-2 antibody (SAM11), or a PAR-2 antagonist (ENMD-1068). These findings suggest that stimulation with HNE can induce IL-13 production by macrophages, especially GM-CSF-dependent macrophages. Accordingly, neutrophil elastase may have a key role in fibrosis associated with chronic inflammation. Copyright © 2015 Elsevier Inc. All rights reserved.

Macrophages and cellular immunity in Drosophila melanogaster.

PubMed

Gold, Katrina S; Brückner, Katja

2015-12-01

The invertebrate Drosophila melanogaster has been a powerful model for understanding blood cell development and immunity. Drosophila is a holometabolous insect, which transitions through a series of life stages from embryo, larva and pupa to adulthood. In spite of this, remarkable parallels exist between Drosophila and vertebrate macrophages, both in terms of development and function. More than 90% of Drosophila blood cells (hemocytes) are macrophages (plasmatocytes), making this highly tractable genetic system attractive for studying a variety of questions in macrophage biology. In vertebrates, recent findings revealed that macrophages have two independent origins: self-renewing macrophages, which reside and proliferate in local microenvironments in a variety of tissues, and macrophages of the monocyte lineage, which derive from hematopoietic stem or progenitor cells. Like vertebrates, Drosophila possesses two macrophage lineages with a conserved dual ontogeny. These parallels allow us to take advantage of the Drosophila model when investigating macrophage lineage specification, maintenance and amplification, and the induction of macrophages and their progenitors by local microenvironments and systemic cues. Beyond macrophage development, Drosophila further serves as a paradigm for understanding the mechanisms underlying macrophage function and cellular immunity in infection, tissue homeostasis and cancer, throughout development and adult life. Copyright © 2016. Published by Elsevier Ltd.

7 CFR 1767.25 - Retained earnings.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 12 2010-01-01 2010-01-01 false Retained earnings. 1767.25 Section 1767.25....25 Retained earnings. The retained earnings accounts identified in this section shall be used by all RUS borrowers. Retained Earnings 433-439 [Reserved] Retained Earnings 433-439 [Reserved] ...

Iron Reduces M1 Macrophage Polarization in RAW264.7 Macrophages Associated with Inhibition of STAT1.

PubMed

Gan, Zhen-Shun; Wang, Qian-Qian; Li, Jia-Hui; Wang, Xu-Liang; Wang, Yi-Zhen; Du, Hua-Hua

2017-01-01

Iron metabolism in inflammation has been mostly characterized in macrophages exposed to pathogens or inflammatory conditions. The aim of this study is to investigate the cross-regulatory interactions between M1 macrophage polarization and iron metabolism. Firstly, we characterized the transcription of genes related to iron homeostasis in M1 RAW264.7 macrophages stimulated by IFN- γ . The molecular signature of M1 macrophages showed high levels of iron storage (ferritin), a low level of iron export (ferroportin), and changes of iron regulators (hepcidin and transferrin receptors), which favour iron sequestration in the reticuloendothelial system and are benefit for inflammatory disorders. Then, we evaluated the effect of iron on M1 macrophage polarization. Iron significantly reduced mRNA levels of IL-6, IL-1 β , TNF- α , and iNOS produced by IFN- γ -polarized M1 macrophages. Immunofluorescence analysis showed that iron also reduced iNOS production. However, iron did not compromise but enhanced the ability of M1-polarized macrophages to phagocytose FITC-dextran. Moreover, we demonstrated that STAT1 inhibition was required for reduction of iNOS and M1-related cytokines production by the present of iron. Together, these findings indicated that iron decreased polarization of M1 macrophages and inhibited the production of the proinflammatory cytokines. The results expanded our knowledge about the role of iron in macrophage polarization.

The macrophage marker translocator protein (TSPO) is down-regulated on pro-inflammatory 'M1' human macrophages.

PubMed

Narayan, Nehal; Mandhair, Harpreet; Smyth, Erica; Dakin, Stephanie Georgina; Kiriakidis, Serafim; Wells, Lisa; Owen, David; Sabokbar, Afsie; Taylor, Peter

2017-01-01

The translocator protein (TSPO) is a mitochondrial membrane protein, of as yet uncertain function. Its purported high expression on activated macrophages, has lent utility to TSPO targeted molecular imaging in the form of positron emission tomography (PET), as a means to detect and quantify inflammation in vivo. However, existing literature regarding TSPO expression on human activated macrophages is lacking, mostly deriving from brain tissue studies, including studies of brain malignancy, and inflammatory diseases such as multiple sclerosis. Here, we utilized three human sources of monocyte derived macrophages (MDM), from THP-1 monocytes, healthy peripheral blood monocytes and synovial fluid monocytes from patients with rheumatoid arthritis, to undertake a detailed investigation of TSPO expression in activated macrophages. In this work, we demonstrate a consistent down-regulation of TSPO mRNA and protein in macrophages activated to a pro-inflammatory, or 'M1' phenotype. Conversely, stimulation of macrophages to an M2 phenotype with IL-4, dexamethasone or TGF-β1 did not alter TSPO expression, regardless of MDM source. The reasons for this are uncertain, but our study findings add some supporting evidence for recent investigations concluding that TSPO may be involved in negative regulation of inflammatory responses in macrophages.

Tumor-associated macrophages as a paradigm of macrophage plasticity, diversity, and polarization: lessons and open questions.

PubMed

Mantovani, Alberto; Locati, Massimo

2013-07-01

Macrophages are present in all body compartments, including cancerous tissues, and their functions are profoundly affected by signals from the microenvironment under homeostatic and pathological conditions. Tumor-associated macrophages are a major cellular component of cancer-related inflammation and have served as a paradigm for the plasticity and functional polarization of mononuclear phagocytes. Tumor-associated macrophages can exert dual influence of cancer depending on the activation state, with classically activated (M1) and alternatively activated (M2) cells generally exerting antitumoral and protumoral functions, respectively. These are extremes in a continuum of polarization states in a universe of diversity. Tumor-associated macrophages affect virtually all aspects of tumor tissues, including stem cells, metabolism, angiogenesis, invasion, and metastasis. Progress has been made in defining signaling molecules, transcription factors, epigenetic changes, and repertoire of microRNAs underlying macrophage polarization. Preclinical and early clinical data suggest that macrophages may serve as tools for the development of innovative diagnostic and therapeutic strategies in cancer and chronic nonresolving inflammatory diseases.

Studies on palauan medicinal herbs. II. Activation of mouse macrophages RAW 264.7 by Ongael, leaves of Phaleria cumingii (Meisn.) F. Vill. and its acylglucosylsterols.

PubMed

Matsuda, Hideaki; Tokunaga, Masashi; Iwahashi, Hiroyasu; Naruto, Shunsuke; Yagi, Hideki; Masuko, Takashi; Kubo, Michinori

2005-05-01

The extract of Ongael [leaves of Phaleria cumingii (MEISN.) F. VILL.], a Palauan medicinal herb, enhanced an in vitro phagocytic activity of mouse macrophages RAW 264.7 cells (RAW 264.7). Activity-guided fractionation of the Ongael extract by the in vitro phagocytosis assay using RAW 264.7 led to the isolation of a mixture of acylglucosylsterols (1) as an active constituent along with other inactive constituents, tetracosanol and mangiferin. On the basis of chemical modifications and spectral analyses, the compound 1 was deduced to be a mixture of the known 3-O-(6-O-acyl-beta-D-glucosyl)-beta-sitosterols, the acyl moiety being mainly palmitoyl (57%), oleoyl (12%) and alpha-linolenoyl (12%) with small amount of stearoyl (7%) and linoleoyl (4%).

Developmental origin of lung macrophage diversity

PubMed Central

Tan, Serena Y. S.; Krasnow, Mark A.

2016-01-01

Macrophages are specialized phagocytic cells, present in all tissues, which engulf and digest pathogens, infected and dying cells, and debris, and can recruit and regulate other immune cells and the inflammatory response and aid in tissue repair. Macrophage subpopulations play distinct roles in these processes and in disease, and are typically recognized by differences in marker expression, immune function, or tissue of residency. Although macrophage subpopulations in the brain have been found to have distinct developmental origins, the extent to which development contributes to macrophage diversity between tissues and within tissues is not well understood. Here, we investigate the development and maintenance of mouse lung macrophages by marker expression patterns, genetic lineage tracing and parabiosis. We show that macrophages populate the lung in three developmental waves, each giving rise to a distinct lineage. These lineages express different markers, reside in different locations, renew in different ways, and show little or no interconversion. Thus, development contributes significantly to lung macrophage diversity and targets each lineage to a different anatomical domain. PMID:26952982

Bicruciate retaining

PubMed Central

2016-01-01

Total knee replacement (TKR) is a procedure used to treat knee arthropathy. Patients’ dissatisfaction is still relevant (literature reports dissatisfaction rates as high as 40%). The anterior cruciate ligament is usually removed while performing a total knee arthroplasty, thus changing knee biomechanics. As patients’ mean age to surgery is decreasing, bicruciate retaining models, which preserve normal biomechanics, may be useful in increasing patients’ outcomes. Limited data concerning bicruciate retaining arthroplasty is available; although clinical results are encouraging, there are concerns regarding surgical exposure, anterior cruciate integrity evaluation, and implant fixation. PMID:27162778

Macrophage Heterogeneity and Plasticity: Impact of Macrophage Biomarkers on Atherosclerosis

PubMed Central

Martínez, María Sofía; Palmar, Jim; Bautista, Jordan; Chávez-Castillo, Mervin; Gómez, Alexis; Bermúdez, Valmore

2015-01-01

Cardiovascular disease (CVD) is a global epidemic, currently representing the worldwide leading cause of morbidity and mortality. Atherosclerosis is the fundamental pathophysiologic component of CVD, where the immune system plays an essential role. Monocytes and macrophages are key mediators in this aspect: due to their heterogeneity and plasticity, these cells may act as either pro- or anti-inflammatory mediators. Indeed, monocytes may develop heterogeneous functional phenotypes depending on the predominating pro- or anti-inflammatory microenvironment within the lesion, resulting in classic, intermediate, and non-classic monocytes, each with strikingly differing features. Similarly, macrophages may also adopt heterogeneous profiles being mainly M1 and M2, the former showing a proinflammatory profile while the latter demonstrates anti-inflammatory traits; they are further subdivided in several subtypes with more specialized functions. Furthermore, macrophages may display plasticity by dynamically shifting between phenotypes in response to specific signals. Each of these distinct cell profiles is associated with diverse biomarkers which may be exploited for therapeutic intervention, including IL-10, IL-13, PPAR-γ, LXR, NLRP3 inflammasomes, and microRNAs. Direct modulation of the molecular pathways concerning these potential macrophage-related targets represents a promising field for new therapeutic alternatives in atherosclerosis and CVD. PMID:26491604

Nramp1 promotes efficient macrophage recycling of iron following erythrophagocytosis in vivo

PubMed Central

Soe-Lin, Shan; Apte, Sameer S.; Andriopoulos, Billy; Andrews, Marc C.; Schranzhofer, Matthias; Kahawita, Tanya; Garcia-Santos, Daniel; Ponka, Prem

2009-01-01

Natural resistance-associated macrophage protein 1 (Nramp1) is a divalent metal transporter expressed exclusively in phagocytic cells. We hypothesized that macrophage Nramp1 may participate in the recycling of iron acquired from phagocytosed senescent erythrocytes. To evaluate the role of Nramp1 in vivo, the iron parameters of WT and KO mice were analyzed after acute and chronic induction of hemolytic anemia. We found that untreated KO mice exhibited greater serum transferrin saturation and splenic iron content with higher duodenal ferroportin (Fpn) and divalent metal transporter 1 (DMT1) expression. Furthermore, hepatocyte iron content and hepcidin mRNA levels were dramatically lower in KO mice, indicating that hepcidin levels can be regulated by low-hepatocyte iron stores despite increased transferrin saturation. After acute treatment with the hemolytic agent phenylhydrazine (Phz), KO mice experienced a significant decrease in transferrin saturation and hematocrit, whereas WT mice were relatively unaffected. After a month-long Phz regimen, KO mice retained markedly increased quantities of iron within the liver and spleen and exhibited more pronounced splenomegaly and reticulocytosis than WT mice. After injection of 59Fe-labeled heat-damaged reticulocytes, KO animals accumulated erythrophagocytosed 59Fe within their liver and spleen, whereas WT animals efficiently recycled phagocytosed 59Fe to the marrow and erythrocytes. These data imply that without Nramp1, iron accumulates within the liver and spleen during erythrophagocytosis and hemolytic anemia, supporting our hypothesis that Nramp1 promotes efficient hemoglobin iron recycling in macrophages. Our observations suggest that mutations in Nramp1 could result in a novel form of human hereditary iron overload. PMID:19321419

Nramp1 promotes efficient macrophage recycling of iron following erythrophagocytosis in vivo.

PubMed

Soe-Lin, Shan; Apte, Sameer S; Andriopoulos, Billy; Andrews, Marc C; Schranzhofer, Matthias; Kahawita, Tanya; Garcia-Santos, Daniel; Ponka, Prem

2009-04-07

Natural resistance-associated macrophage protein 1 (Nramp1) is a divalent metal transporter expressed exclusively in phagocytic cells. We hypothesized that macrophage Nramp1 may participate in the recycling of iron acquired from phagocytosed senescent erythrocytes. To evaluate the role of Nramp1 in vivo, the iron parameters of WT and KO mice were analyzed after acute and chronic induction of hemolytic anemia. We found that untreated KO mice exhibited greater serum transferrin saturation and splenic iron content with higher duodenal ferroportin (Fpn) and divalent metal transporter 1 (DMT1) expression. Furthermore, hepatocyte iron content and hepcidin mRNA levels were dramatically lower in KO mice, indicating that hepcidin levels can be regulated by low-hepatocyte iron stores despite increased transferrin saturation. After acute treatment with the hemolytic agent phenylhydrazine (Phz), KO mice experienced a significant decrease in transferrin saturation and hematocrit, whereas WT mice were relatively unaffected. After a month-long Phz regimen, KO mice retained markedly increased quantities of iron within the liver and spleen and exhibited more pronounced splenomegaly and reticulocytosis than WT mice. After injection of (59)Fe-labeled heat-damaged reticulocytes, KO animals accumulated erythrophagocytosed (59)Fe within their liver and spleen, whereas WT animals efficiently recycled phagocytosed (59)Fe to the marrow and erythrocytes. These data imply that without Nramp1, iron accumulates within the liver and spleen during erythrophagocytosis and hemolytic anemia, supporting our hypothesis that Nramp1 promotes efficient hemoglobin iron recycling in macrophages. Our observations suggest that mutations in Nramp1 could result in a novel form of human hereditary iron overload.

Blade retainer assembly

NASA Technical Reports Server (NTRS)

Luebering, G. W. (Inventor)

1977-01-01

A retaining assembly is provided for locking radially extending blades in a rotor disc associated with a gas turbine engine. The assembly includes a pair of spaced apart lugs axially extending from one side of the disc to form an access gap for insertion of a blade tang into a dovetail slot in the rotor disc. A pair of axially aligned inwardly facing recesses are disposed in the lugs. A retaining member resides in the recesses and extends across the gap to preclude egress of the blade tang from the dovetail slot. The retaining member includes at least one axially extending protrusion adapted to radially overlap and abuttingly engage a radially inwardly facing abutment surface on the lugs.

Alternatively Activated (M2) Macrophage Phenotype Is Inducible by Endothelin-1 in Cultured Human Macrophages.

PubMed

Soldano, Stefano; Pizzorni, Carmen; Paolino, Sabrina; Trombetta, Amelia Chiara; Montagna, Paola; Brizzolara, Renata; Ruaro, Barbara; Sulli, Alberto; Cutolo, Maurizio

2016-01-01

Alternatively activated (M2) macrophages are phenotypically characterized by the expression of specific markers, mainly macrophage scavenger receptors (CD204 and CD163) and mannose receptor-1 (CD206), and participate in the fibrotic process by over-producing pro-fibrotic molecules, such as transforming growth factor-beta1 (TGFbeta1) and metalloproteinase (MMP)-9. Endothelin-1 (ET-1) is implicated in the fibrotic process, exerting its pro-fibrotic effects through the interaction with its receptors (ETA and ETB). The study investigated the possible role of ET-1 in inducing the transition from cultured human macrophages into M2 cells. Cultured human monocytes (THP-1 cell line) were activated into macrophages (M0 macrophages) with phorbol myristate acetate and subsequently maintained in growth medium (M0-controls) or treated with either ET-1 (100nM) or interleukin-4 (IL-4, 10ng/mL, M2 inducer) for 72 hours. Similarly, primary cultures of human peripheral blood monocyte (PBM)-derived macrophages obtained from healthy subjects, were maintained in growth medium (untreated cells) or treated with ET-1 or IL-4 for 6 days. Both M0 and PBM-derived macrophages were pre-treated with ET receptor antagonist (ETA/BRA, bosentan 10-5M) for 1 hour before ET-1 stimulation. Protein and gene expression of CD204, CD206, CD163, TGFbeta1 were analysed by immunocytochemistry, Western blotting and quantitative real time polymerase chain reaction (qRT-PCR). Gene expression of interleukin(IL)-10 and macrophage derived chemokine (CCL-22) was evaluated by qRT-PCR. MMP-9 production was investigated by gel zymography. ET-1 significantly increased the expression of M2 phenotype markers CD204, CD206, CD163, IL-10 and CCL-22, and the production of MMP-9 in both cultures of M0 and PBM-derived macrophages compared to M0-controls and untreated cells. In cultured PBM-derived macrophages, ET-1 increased TGFbeta1 protein and gene expression compared to untreated cells. The ET-1-mediated effects were

Yersinia pestis and host macrophages: immunodeficiency of mouse macrophages induced by YscW.

PubMed

Bi, Yujing; Du, Zongmin; Han, Yanping; Guo, Zhaobiao; Tan, Yafang; Zhu, Ziwen; Yang, Ruifu

2009-09-01

The virulence of the pathogenic Yersinia species depends on a plasmid-encoded type III secretion system (T3SS) that transfers six Yersinia outer protein (Yop) effector proteins into the cytoplasm of eukaryotic cells, leading to disruption of host defence mechanisms. It is shown in this study that Yersinia pestis YscW, a protein of the T3SS injectisome, contributes to the induction of a deficiency in phagocytosis in host macrophages and a reduction in their antigen-presenting capacity. A Y. pestis strain lacking yscW had no effect on uptake by host macrophages. In mice infected with wild-type Y. pestis, the yscW mutant or a complement strain, immunodeficiency was observed in host macrophages compared with those from uninfected mice. However, the phagocytosis and antigen presenting capacities of macrophages infected by yscW mutant strain both in vivo and in vitro were significantly higher than those by wild type strain. Consistent with this finding, when YscW was expressed in the RAW264.7 macrophage cell line, phagocytosis and antigen-presenting capacities were significantly lower than those of the control groups. These results indicate that Y. pestis YscW may directly induce immunodeficiency in murine macrophages by crippling their phagocytosis and antigen-presenting capacities. These data provide evidences to Y. pestis pathogenesis that some proteins in T3SS injectisome, such as YscW protein, might play independent roles in disrupting host defense apart from their known functions.

E2f1–3 Are Critical for Myeloid Development*

PubMed Central

Trikha, Prashant; Sharma, Nidhi; Opavsky, Rene; Reyes, Andres; Pena, Clarissa; Ostrowski, Michael C.; Roussel, Martine F.; Leone, Gustavo

2011-01-01

Hematopoietic development involves the coordinated activity of differentiation and cell cycle regulators. In current models of mammalian cell cycle control, E2f activators (E2f1, E2f2, and E2f3) are portrayed as the ultimate transcriptional effectors that commit cells to enter and progress through S phase. Using conditional gene knock-out strategies, we show that E2f1–3 are not required for the proliferation of early myeloid progenitors. Rather, these E2fs are critical for cell survival and proliferation at two distinct steps of myeloid development. First, E2f1–3 are required as transcriptional repressors for the survival of CD11b+ myeloid progenitors, and then they are required as activators for the proliferation of CD11b+ macrophages. In bone marrow macrophages, we show that E2f1–3 respond to CSF1-Myc mitogenic signals and serve to activate E2f target genes and promote their proliferation. Together, these findings expose dual functions for E2f1–3 at distinct stages of myeloid development in vivo, first as repressors in cell survival and then as activators in cell proliferation. In summary, this work places E2f1–3 in a specific signaling cascade that is critical for myeloid development in vivo. PMID:21115501

Macrophage Phenotype Modulation by CXCL4 in Atherosclerosis.

PubMed

Gleissner, Christian A

2012-01-01

During atherogenesis, blood monocytes transmigrate into the subendothelial space and differentiate toward macrophages and foam cells. The major driver of monocyte-macrophage differentiation is macrophage colony-stimulating factor (M-CSF). M-CSF-induced macrophages are important promoters of atherogenesis as demonstrated in M-CSF and M-CSF receptor knock out mice. However, M-CSF is not the only relevant promoter of macrophage differentiation. The platelet chemokine CXCL4 also prevents monocyte apoptosis and promotes macrophage differentiation in vitro. It is secreted from activated platelets and has effects on various cell types relevant in atherogenesis. Knocking out the Pf4 gene coding for CXCL4 in Apoe(-/-) mice leads to reduced atherogenesis. Thus, it seems likely that CXC4-induced macrophages may have specific pro-atherogenic capacities. We have studied CXC4-induced differentiation of human macrophages using gene chips, systems biology, and functional in vitro and ex vivo experiments. Our data indicate that CXCL4-induced macrophages are distinct from both their M-CSF-induced counterparts and other known macrophage polarizations like M1 macrophages (induced by lipopolysaccharide and interferon-gamma) or M2 macrophages (induced by interleukin-4). CXCL4-induced macrophages have distinct phenotypic and functional characteristics, e.g., the complete loss of the hemoglobin-haptoglobin (Hb-Hp) scavenger receptor CD163 which is necessary for effective hemoglobin clearance after plaque hemorrhage. Lack of CD163 is accompanied by the inability to upregulate the atheroprotective enzyme heme oxygenase-1 in response to Hb-Hp complexes. This review covers the current knowledge about CXCL4-induced macrophages. Based on their unique properties, we have suggested to call these macrophages "M4." CXCL4 may represent an important orchestrator of macrophage heterogeneity within atherosclerotic lesions. Further dissecting its effects on macrophage differentiation may help to

Macrophage Phenotype Modulation by CXCL4 in Atherosclerosis

PubMed Central

Gleissner, Christian A.

2011-01-01

During atherogenesis, blood monocytes transmigrate into the subendothelial space and differentiate toward macrophages and foam cells. The major driver of monocyte–macrophage differentiation is macrophage colony-stimulating factor (M-CSF). M-CSF-induced macrophages are important promoters of atherogenesis as demonstrated in M-CSF and M-CSF receptor knock out mice. However, M-CSF is not the only relevant promoter of macrophage differentiation. The platelet chemokine CXCL4 also prevents monocyte apoptosis and promotes macrophage differentiation in vitro. It is secreted from activated platelets and has effects on various cell types relevant in atherogenesis. Knocking out the Pf4 gene coding for CXCL4 in Apoe−/− mice leads to reduced atherogenesis. Thus, it seems likely that CXC4-induced macrophages may have specific pro-atherogenic capacities. We have studied CXC4-induced differentiation of human macrophages using gene chips, systems biology, and functional in vitro and ex vivo experiments. Our data indicate that CXCL4-induced macrophages are distinct from both their M-CSF-induced counterparts and other known macrophage polarizations like M1 macrophages (induced by lipopolysaccharide and interferon-gamma) or M2 macrophages (induced by interleukin-4). CXCL4-induced macrophages have distinct phenotypic and functional characteristics, e.g., the complete loss of the hemoglobin–haptoglobin (Hb–Hp) scavenger receptor CD163 which is necessary for effective hemoglobin clearance after plaque hemorrhage. Lack of CD163 is accompanied by the inability to upregulate the atheroprotective enzyme heme oxygenase-1 in response to Hb–Hp complexes. This review covers the current knowledge about CXCL4-induced macrophages. Based on their unique properties, we have suggested to call these macrophages “M4.” CXCL4 may represent an important orchestrator of macrophage heterogeneity within atherosclerotic lesions. Further dissecting its effects on macrophage differentiation may

Mimicking the tumor microenvironment to regulate macrophage phenotype and assessing chemotherapeutic efficacy in embedded cancer cell/macrophage spheroid models.

PubMed

Tevis, Kristie M; Cecchi, Ryan J; Colson, Yolonda L; Grinstaff, Mark W

2017-03-01

Tumor associated macrophages (TAMs) are critical stromal components intimately involved with the progression, invasion, and metastasis of cancer cells. To address the need for an in vitro system that mimics the clinical observations of TAM localizations and subsequent functional performance, a cancer cell/macrophage spheroid model is described. The central component of the model is a triple negative breast cancer spheroid embedded in a three-dimensional collagen gel. Macrophages are incorporated in two different ways. The first is a heterospheroid, a spheroid containing both tumor cells and macrophages. The heterospheroid mimics the population of TAMs infiltrated into the tumor mass, thus being exposed to hypoxia and metabolic gradients. In the second model, macrophages are diffusely seeded in the collagen surrounding the spheroid, thus modeling TAMs in the cancer stroma. The inclusion of macrophages as a heterospheroid changes the metabolic profile, indicative of synergistic growth. In contrast, macrophages diffusely seeded in the collagen bear the same profile regardless of the presence of a tumor cell spheroid. The macrophages in the heterospheroid secrete EGF, a cytokine critical to tumor/macrophage co-migration, and an EGF inhibitor decreases the metabolic activity of the heterospheroid, which is not observed in the other systems. The increased secretion of IL-10 indicates that the heterospheroid macrophages follow an M2/TAM differentiation pathway. Lastly, the heterospheroid exhibits resistance to paclitaxel. In summary, the collagen embedded heterospheroid model promotes TAM-like characteristics, and will be of utility in cancer biology and drug discovery. Two in vitro collagen-embedded multicellular spheroid models are described that mimic the clinical observations of macrophage localization within a tumor. Incorporation of macrophages within a breast cancer spheroid emphasizes cell-cell interactions with subsequent differentiation toward a tumor

SdrF, a Staphylococcus epidermidis Surface Protein, Contributes to the Initiation of Ventricular Assist Device Driveline–Related Infections

PubMed Central

Arrecubieta, Carlos; Toba, Faustino A.; von Bayern, Manuel; Akashi, Hirokazu; Deng, Mario C.; Naka, Yoshifumi; Lowy, Franklin D.

2009-01-01

Staphylococcus epidermidis remains the predominant pathogen in prosthetic-device infections. Ventricular assist devices, a recently developed form of therapy for end-stage congestive heart failure, have had considerable success. However, infections, most often caused by Staphylococcus epidermidis, have limited their long-term use. The transcutaneous driveline entry site acts as a potential portal of entry for bacteria, allowing development of either localized or systemic infections. A novel in vitro binding assay using explanted drivelines obtained from patients undergoing transplantation and a heterologous lactococcal system of surface protein expression were used to identify S. epidermidis surface components involved in the pathogenesis of driveline infections. Of the four components tested, SdrF, SdrG, PIA, and GehD, SdrF was identified as the primary ligand. SdrF adherence was mediated via its B domain attaching to host collagen deposited on the surface of the driveline. Antibodies directed against SdrF reduced adherence of S. epidermidis to the drivelines. SdrF was also found to adhere with high affinity to Dacron, the hydrophobic polymeric outer surface of drivelines. Solid phase binding assays showed that SdrF was also able to adhere to other hydrophobic artificial materials such as polystyrene. A murine model of infection was developed and used to test the role of SdrF during in vivo driveline infection. SdrF alone was able to mediate bacterial adherence to implanted drivelines. Anti-SdrF antibodies reduced S. epidermidis colonization of implanted drivelines. SdrF appears to play a key role in the initiation of ventricular assist device driveline infections caused by S. epidermidis. This pluripotential adherence capacity provides a potential pathway to infection with SdrF-positive commensal staphylococci first adhering to the external Dacron-coated driveline at the transcutaneous entry site, then spreading along the collagen-coated internal portion of the

The influence of macrophage growth factors on Theiler's Murine Encephalomyelitis Virus (TMEV) infection and activation of macrophages.

PubMed

Schneider, Karin M; Watson, Neva B; Minchenberg, Scott B; Massa, Paul T

2018-02-01

Macrophages are common targets for infection and innate immune activation by many pathogenic viruses including the neurotropic Theiler's Murine Encephalomyelitis Virus (TMEV). As both infection and innate activation of macrophages are key determinants of viral pathogenesis especially in the central nervous system (CNS), an analysis of macrophage growth factors on these events was performed. C3H mouse bone-marrow cells were differentiated in culture using either recombinant macrophage colony stimulating factor (M-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF), inoculated with TMEV (BeAn) and analyzed at various times thereafter. Cytokine RNA and protein analysis, virus titers, and flow cytometry were performed to characterize virological parameters under these culture conditions. GM-CSF-differentiated macrophages showed higher levels of TMEV viral RNA and proinflammatory molecules compared to infected M-CSF-differentiated cells. Thus, GM-CSF increases both TMEV infection and TMEV-induced activation of macrophages compared to that seen with M-CSF. Moreover, while infectious viral particles decreased from a peak at 12h to undetectable levels at 48h post infection, TMEV viral RNA remained higher in GM-CSF- compared to M-CSF-differentiated macrophages in concert with increased proinflammatory gene expression. Analysis of a possible basis for these differences determined that glycolytic rates contributed to heightened virus replication and proinflammatory cytokine secretion in GM-CSF compared to M-CSF-differentiated macrophages. In conclusion, we provide evidence implicating a role for GM-CSF in promoting virus replication and proinflammatory cytokine expression in macrophages, indicating that GM-CSF may be a key factor for TMEV infection and the induction of chronic TMEV-induced immunopathogenesis in the CNS. Copyright © 2017 Elsevier Ltd. All rights reserved.

Polarization of macrophages in the tumor microenvironment is influenced by EGFR signaling within colon cancer cells

PubMed Central

Zhang, Weina; Chen, Lechuang; Ma, Kai; Zhao, Yahui; Liu, Xianghe; Wang, Yu; Liu, Mei; Liang, Shufang; Zhu, Hongxia; Xu, Ningzhi

2016-01-01

Epidermal growth factor receptor (EGFR) is a target of colon cancer therapy, but the effects of this therapy on the tumor microenvironment remain poorly understood. Our in vivo studies showed that cetuximab, an anti-EGFR monoclonal antibody, effectively inhibited AOM/DSS-induced, colitis-associated tumorigenesis, downregulated M2-related markers, and decreased F4/80+/CD206+ macrophage populations. Treatment with conditioned medium of colon cancer cells increased macrophage expression of the M2-related markers arginase-1 (Arg1), CCL17, CCL22, IL-10 and IL-4. By contrast, conditioned medium of EGFR knockout colon cancer cells inhibited expression of these M2-related markers and induced macrophage expression of the M1-related markers inducible nitric oxide synthase (iNOS), IL-12, TNF-α and CCR7. EGFR knockout in colon cancer cells inhibited macrophage-induced promotion of xenograft tumor growth. Moreover, colon cancer-derived insulin-like growth factor-1 (IGF-1) increased Arg1 expression, and treatment with the IGF1R inhibitor AG1024 inhibited that increase. These results suggest that inhibition of EGFR signaling in colon cancer cells modulates cytokine secretion (e.g. IGF-1) and prevents M1-to-M2 macrophage polarization, thereby inhibiting cancer cell growth. PMID:27683110

Polyurethane retainers for ball bearings

NASA Technical Reports Server (NTRS)

Christy, R. I.

1973-01-01

Evaluation of a new ball bearing retainer material is reported. A special composite polyurethane foam ball retainer has been developed that has virtually zero wear, is chemically inert to hydrocarbon lubricants, and stores up to 60 times as much lubricant per unit volume as the most commonly used retainer material, cotton phenolic. This new retainer concept shows promise of years of ball bearing operation without reoiling, based on life testing in high vacuum.

Voluntary exercise attenuates obesity-associated inflammation through ghrelin expressed in macrophages.

PubMed

Kizaki, Takako; Maegawa, Taketeru; Sakurai, Takuya; Ogasawara, Jun-etsu; Ookawara, Tomomi; Oh-ishi, Shuji; Izawa, Tetsuya; Haga, Shukoh; Ohno, Hideki

2011-09-30

Chronic low-level inflammation is associated with obesity and a sedentary lifestyle, causing metabolic disturbances such as insulin resistance. Exercise training has been shown to decrease chronic low-level systemic inflammation in high-fat diet (HFD)-induced obesity. However, the molecular mechanisms mediating its beneficial effects are not fully understood. Ghrelin is a peptide hormone predominantly produced in the stomach that stimulates appetite and induces growth hormone release. In addition to these well-known functions, recent studies suggest that ghrelin localizes to immune cells and exerts an anti-inflammatory effect. The purpose of the current study was to investigate the role of ghrelin expressed in macrophages in the anti-inflammatory effects of voluntary exercise training. Expression of tumor necrosis factor-α (TNF-α), monocyte chemotactic protein (MCP)-1 and F4/80 was increased in adipose tissue from mice fed a HFD (HFD mice) compared with mice fed a standard diet (SD mice), whereas the expression of these inflammatory cytokines was markedly decreased in mice performing voluntary wheel running during the feeding of a HFD (HFEx mice). The expression of TNF-α was also increased in peritoneal macrophages by a HFD and exercise training inhibited the increase of TNF-α expression. Interestingly, expression of ghrelin in peritoneal macrophages was decreased by a HFD and recovered by exercise training. Suppression of ghrelin expression by siRNA increased TNF-α expression and LPS-stimulated NF-κB activation in RAW264 cells, which is a macrophage cell line. TNF-α expression by stimulation with LPS was significantly suppressed in RAW264 cells cultured in the presence of ghrelin. These results suggest that ghrelin exerts potent anti-inflammatory effects in macrophages and functions as a mediator of the beneficial effects of exercise training. Copyright © 2011 Elsevier Inc. All rights reserved.

Lymphoid tissue and plasmacytoid dendritic cells and macrophages do not share a common macrophage-dendritic cell-restricted progenitor.

PubMed

Sathe, Priyanka; Metcalf, Donald; Vremec, David; Naik, Shalin H; Langdon, Wallace Y; Huntington, Nicholas D; Wu, Li; Shortman, Ken

2014-07-17

The relationship between dendritic cells (DCs) and macrophages is often debated. Here we ask whether steady-state, lymphoid-tissue-resident conventional DCs (cDCs), plasmacytoid DCs (pDCs), and macrophages share a common macrophage-DC-restricted precursor (MDP). Using new clonal culture assays combined with adoptive transfer, we found that MDP fractions isolated by previous strategies are dominated by precursors of macrophages and monocytes, include some multipotent precursors of other hematopoietic lineages, but contain few precursors of resident cDCs and pDCs and no detectable common precursors restricted to these DC types and macrophages. Overall we find no evidence for a common restricted MDP leading to both macrophages and FL-dependent, resident cDCs and pDCs. Copyright © 2014 Elsevier Inc. All rights reserved.

Interactions Between Macrophages of Guinea Pigs and Salmonellae III. Bactericidal Action and Cytophilic Antibodies of Macrophages of Infected Guinea Pigs

PubMed Central

Hsu, H. S.; Mayo, Donald R.

1973-01-01

The fate of virulent Salmonella typhimurium within macrophages of guinea pigs was assessed by a suspended cell culture procedure. The present study confirmed that macrophages of normal guinea pigs were capable of inactivating the ingested salmonellae. Macrophages of previously infected guinea pigs were not endowed with any significant increase in their ability to eliminate the ingested pathogen. However, the immune macrophages were observed to clump together tightly when they were exposed to salmonellae. This phenomenon was attributed to the presence of specific cytophilic antibodies on the immune macrophages. When immune macrophages were inactivated with Merthiolate, they agglutinated with both the H and the O antigens of S. typhimurium, but not with the O antigens of other species of Salmonella nor with the O antigens of Escherichia coli. Cytophilic antibodies could be eluted from immune macrophages by incubation in the absence of immune serum. Conversely, cytophilic antibodies could be passively transferred onto normal macrophages by incubation in the presence of immune serum. Furthermore, using immune serum previously adsorbed with the O antigens of S. typhimurium, cytophilic antibodies against the H antigens alone could be transferred onto normal macrophages, or those against the O antigens alone could be eluted from immune macrophages. These data suggest that immune macrophages possess specific cytophilic antibodies against both the H and the O antigens of S. typhimurium. It is proposed that the presence of cytophilic antibodies on immune macrophages represents an expression of antibacterial cellular immunity by enhanced clumping and phagocytic activities of the macrophages. PMID:4579899

Conditioned medium from persistently RSV-infected macrophages alters transcriptional profile and inflammatory response of non-infected macrophages.

PubMed

Rivera-Toledo, Evelyn; Salido-Guadarrama, Iván; Rodríguez-Dorantes, Mauricio; Torres-González, Laura; Santiago-Olivares, Carlos; Gómez, Beatriz

2017-02-15

Cells susceptible to persistent viral infections undergo important changes in their biological functions as a consequence of the expression of viral gene products that are capable of altering the gene expression profile of the host cell. Previously, we reported that persistence of the RSV genome in a mouse macrophage cell line induces important alterations in cell homeostasis, including constitutive expression of IFN-β and other pro-inflammatory cytokines. Here, we postulated that changes in the homeostasis of non-infected macrophages could be induced by soluble factors secreted by persistently RSV- infected macrophages. To test this hypothesis, non-infected mouse macrophages were treated with conditioned medium (CM) collected from cultures of persistently RSV-infected macrophages. Total RNA was extracted and a microarray-based gene expression analysis was performed. Non-infected macrophages, treated under similar conditions with CM obtained from cultures of non-infected macrophages, were used as a control to establish differential gene expression between the two conditions. Results showed that CM from the persistently RSV-infected cultures altered expression of a total of 95 genes in non-infected macrophages, resulting in an antiviral gene-transcription profile along with inhibition of the inflammatory response, since some inflammatory genes were down-regulated, including Nlrp3 and Il-1 β, both related to the inflammasome pathway. However, down-regulation of Nlrp3 and Il-1 β was reversible upon acute RSV infection. Additionally, we observed that the inflammatory response, evaluated by secreted IL-1 β, a final product of the inflammasome activity, was enhanced during acute RSV infection in macrophages treated with CM from persistently RSV-infected cultures, compared to that in macrophages treated with the control CM. This suggests that soluble factors secreted during RSV persistence may induce an exacerbated inflammatory response in non-infected cells

Nicotine Impairs Macrophage Control of Mycobacterium tuberculosis.

PubMed

Bai, Xiyuan; Stitzel, Jerry A; Bai, An; Zambrano, Cristian A; Phillips, Matthew; Marrack, Philippa; Chan, Edward D

2017-09-01

Pure nicotine impairs macrophage killing of Mycobacterium tuberculosis (MTB), but it is not known whether the nicotine component in cigarette smoke (CS) plays a role. Moreover, the mechanisms by which nicotine impairs macrophage immunity against MTB have not been explored. To neutralize the effects of nicotine in CS extract, we used a competitive inhibitor to the nicotinic acetylcholine receptor (nAChR)-mecamylamine-as well as macrophages derived from mice with genetic disruption of specific subunits of nAChR. We also determined whether nicotine impaired macrophage autophagy and whether nicotine-exposed T regulatory cells (Tregs) could subvert macrophage anti-MTB immunity. Mecamylamine reduced the CS extract increase in MTB burden by 43%. CS extract increase in MTB was also significantly attenuated in macrophages from mice with genetic disruption of either the α7, β2, or β4 subunit of nAChR. Nicotine inhibited autophagosome formation in MTB-infected THP-1 cells and primary murine alveolar macrophages, as well as increased the intracellular MTB burden. Nicotine increased migration of THP-1 cells, consistent with the increased number of macrophages found in the lungs of smokers. Nicotine induced Tregs to produce transforming growth factor-β. Naive mouse macrophages co-cultured with nicotine-exposed Tregs had significantly greater numbers of viable MTB recovered with increased IL-10 production and urea production, but no difference in secreted nitric oxide as compared with macrophages cocultured with unexposed Tregs. We conclude that nicotine in CS plays an important role in subverting macrophage control of MTB infection.

Emodin suppresses pulmonary metastasis of breast cancer cells accompanied with decreased macrophage recruitment and M2 polarization in the lungs

PubMed Central

Jia, Xuemei; Yu, Fang; Wang, Junfeng; Iwanowycz, Stephen; Saaoud, Fatma; Wang, Yuzhen; Hu, Jun; Wang, Qian; Fan, Daping

2014-01-01

Purpose Breast cancer is the leading cause of death in female cancer patients due to the lack of effective treatment for metastasis. Macrophages are the most abundant immune cells in the primary and metastatic tumors, and contribute to tumor initiation, progression and metastasis. Emodin has been found to exert anti-tumor effects through promoting cell cycle arrest and apoptosis, and inhibiting angiogenesis, but its effects on tumor-associated macrophages during cancer metastasis have not been investigated. Methods Mice inoculated with 4T1 or EO771 breast cancer cells orthotopically were treated with Emodin after the primary tumors reached 200 mm3 in size. Primary tumor growth, lung metastasis, and macrophage infiltration in the lungs were analyzed. In vitro experiments were performed to examine the effects of Emodin on macrophage migration and M2 polarization, and the underlying mechanisms. Results Emodin significantly suppressed breast cancer lung metastasis in both orthotopic mouse models without apparent effects on primary tumors. Reduced infiltration of F4/80+ macrophages and Ym1+ M2 macrophages in lungs was observed in Emodin-treated mice. In vitro experiments demonstrated that Emodin decreased the migration of macrophages towards tumor cell conditioned medium (TCM) and inhibited macrophage M2 polarization induced by TCM. Mechanistically, Emodin suppressed STAT6 phosphorylation and C/EBPβ expression, two crucial signaling events in macrophage M2 polarization, in macrophages treated with IL-4 or TCM. Conclusion Taken together, our study, for the first time, demonstrated that Emodin suppressed pulmonary metastasis of breast cancer probably through inhibiting macrophage recruitment and M2 polarization in the lungs by reducing STAT6 phosphorylation and C/EBPβ expression. PMID:25311112

Macrophage heterogeneity in liver injury and fibrosis.

PubMed

Tacke, Frank; Zimmermann, Henning W

2014-05-01

Hepatic macrophages are central in the pathogenesis of chronic liver injury and have been proposed as potential targets in combatting fibrosis. Recent experimental studies in animal models revealed that hepatic macrophages are a remarkably heterogeneous population of immune cells that fulfill diverse functions in homeostasis, disease progression, and regression from injury. These range from clearance of pathogens or cellular debris and maintenance of immunological tolerance in steady state conditions; central roles in initiating and perpetuating inflammation in response to injury; promoting liver fibrosis via activating hepatic stellate cells in chronic liver damage; and, finally, resolution of inflammation and fibrosis by degradation of extracellular matrix and release of anti-inflammatory cytokines. Cellular heterogeneity in the liver is partly explained by the origin of macrophages. Hepatic macrophages can either arise from circulating monocytes, which are recruited to the injured liver via chemokine signals, or from self-renewing embryo-derived local macrophages, termed Kupffer cells. Kupffer cells appear essential for sensing tissue injury and initiating inflammatory responses, while infiltrating Ly-6C(+) monocyte-derived macrophages are linked to chronic inflammation and fibrogenesis. In addition, proliferation of local or recruited macrophages may possibly further contribute to their accumulation in injured liver. During fibrosis regression, monocyte-derived cells differentiate into Ly-6C (Ly6C, Gr1) low expressing 'restorative' macrophages and promote resolution from injury. Understanding the mechanisms that regulate hepatic macrophage heterogeneity, either by monocyte subset recruitment, by promoting restorative macrophage polarization or by impacting distinctive macrophage effector functions, may help to develop novel macrophage subset-targeted therapies for liver injury and fibrosis. Copyright © 2014 European Association for the Study of the Liver

Adipose tissue macrophages induce hepatic neutrophil recruitment and macrophage accumulation in mice.

PubMed

Bijnen, Mitchell; Josefs, Tatjana; Cuijpers, Ilona; Maalsen, Constantijn J; van de Gaar, José; Vroomen, Maria; Wijnands, Erwin; Rensen, Sander S; Greve, Jan Willem M; Hofker, Marten H; Biessen, Erik A L; Stehouwer, Coen D A; Schalkwijk, Casper G; Wouters, Kristiaan

2017-10-26

Obesity is a risk factor for non-alcoholic steatohepatitis (NASH). This risk has been attributed to visceral adipose tissue (vAT) expansion associated with increased proinflammatory mediators. Accumulation of CD11c + proinflammatory adipose tissue macrophages (ATM) is an important driver of vAT inflammation. We investigated the role of ATMs in hepatic inflammation during NASH development. vAT isolated from lean, obese or ATM-depleted (using clodronate liposomes) obese mice was transplanted to lean ldlr -/- acceptor mice. Systemic and hepatic inflammation was assessed either after 2 weeks on standard chow or after 8 weeks on high cholesterol diet (HCD) to induce NASH. Transplanting donor vAT from obese mice increased HCD-induced hepatic macrophage content compared with lean-transplanted mice, worsening liver damage. ATM depletion prior to vAT transplantation reduced this increased hepatic macrophage accumulation. On chow, vAT transplantation induced a more pronounced increase in circulating and hepatic neutrophil numbers in obese-transplanted than lean-transplanted mice, while ATM depletion prior to vAT transplantation reversed this effect. Microarray analysis of fluorescence-activated cell sorting of CD11c + and CD11c - macrophages isolated from donor adipose tissue showed that obesity resulted in enhanced expression of neutrophil chemotaxis genes specifically in CD11c + ATMs. Involvement of the neutrophil chemotaxis proteins, CXCL14 and CXCL16, was confirmed by culturing vAT. In humans, CD11c expression in vAT of obese individuals correlated with vAT expression of neutrophil chemotactic genes and with hepatic expression of neutrophil and macrophage marker genes. ATMs from obese vAT induce hepatic macrophage accumulation during NASH development, possibly by enhancing neutrophil recruitment. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise

Fatty acid-binding protein 5 limits the anti-inflammatory response in murine macrophages.

PubMed

Moore, Sherri M; Holt, Vivian V; Malpass, Lillie R; Hines, Ian N; Wheeler, Michael D

2015-10-01

The beginning stages of liver damage induced by various etiologies (i.e. high fat diet, alcohol consumption, toxin exposure) are characterized by abnormal accumulation of lipid in liver. Alterations in intracellular lipid transport, storage, and metabolism accompanied by cellular insult within the liver play an important role in the pathogenesis of liver disease, often involving a sustained inflammatory response. The intracellular lipid transporter, fatty acid binding protein 5 (FABP5), is highly expressed in macrophages and may play an important role in the hepatic inflammatory response after endotoxin exposure in mice. This study tested the hypothesis that FABP5 regulates macrophage response to LPS in male C57bl/6 (wild type) and FABP5 knockout mice, both in vitro and in vivo. Treatment with LPS revealed that loss of FABP5 enhances the number of hepatic F4/80(+) macrophages in the liver despite limited liver injury. Conversely, FABP5 knock out mice display higher mRNA levels of anti-inflammatory cytokines IL-10, arginase, YM-1, and Fizz-1 in liver compared to wild type mice. Bone marrow derived macrophages stimulated with inflammatory (LPS and IFN-γ) or anti-inflammatory (IL-4) mediators also showed significantly higher expression of anti-inflammatory/regulatory factors. These findings reveal a regulatory role of FABP5 in the acute inflammatory response to LPS-induced liver injury, which is consistent with the principle finding that FABP5 is a regulator of macrophage phenotype. Specifically, these findings demonstrate that loss of FABP5 promotes a more anti-inflammatory response. Copyright © 2015 Elsevier Ltd. All rights reserved.

Quantitation of cell-associated carbon nanotubes: selective binding and accumulation of carboxylated carbon nanotubes by macrophages.

PubMed

Wang, Ruhung; Lee, Michael; Kinghorn, Karina; Hughes, Tyler; Chuckaree, Ishwar; Lohray, Rishabh; Chow, Erik; Pantano, Paul; Draper, Rockford

2018-05-26

To understand the influence of carboxylation on the interaction of carbon nanotubes with cells, the amount of pristine multi-walled carbon nanotubes (P-MWNTs) or carboxylated multi-walled carbon nanotubes (C-MWNTs) coated with Pluronic ® F-108 that were accumulated by macrophages was measured by quantifying CNTs extracted from cells. Mouse RAW 264.7 macrophages and differentiated human THP-1 (dTHP-1) macrophages accumulated 80-100 times more C-MWNTs than P-MWNTs during a 24-h exposure at 37 °C. The accumulation of C-MWNTs by RAW 264.7 cells was not lethal; however, phagocytosis was impaired as subsequent uptake of polystyrene beads was reduced after a 20-h exposure to C-MWNTs. The selective accumulation of C-MWNTs suggested that there might be receptors on macrophages that bind C-MWNTs. The binding of C-MWNTs to macrophages was measured as a function of concentration at 4 °C in the absence of serum to minimize the potential interference by serum proteins or temperature-dependent uptake processes. The result was that the cells bound 8.7 times more C-MWNTs than P-MWNTs, consistent with the selective accumulation of C-MWNTs at 37 °C. In addition, serum strongly antagonized the binding of C-MWTS to macrophages, suggesting that serum contained inhibitors of binding. Moreover, inhibitors of class A scavenger receptor (SR-As) reduced the binding of C-MWNTs by about 50%, suggesting that SR-As contribute to the binding and endocytosis of C-MWNTs in macrophages but that other receptors may also be involved. Altogether, the evidence supports the hypothesis that macrophages contain binding sites selective for C-MWNTs that facilitate the high accumulation of C-MWNTs compared to P-MWNTs.

Macrophages in tissue repair, regeneration, and fibrosis

PubMed Central

Wynn, Thomas A.; Vannella, Kevin M.

2016-01-01

Inflammatory monocytes and resident tissue macrophages are key regulators of tissue repair, regeneration, and fibrosis. Following tissue injury, monocytes and macrophages undergo marked phenotypic and functional changes to play critical roles during the initiation, maintenance, and resolution phases of tissue repair. Disturbances in macrophage function can lead to aberrant repair, with uncontrolled inflammatory mediator and growth factor production, deficient generation of anti-inflammatory macrophages, or failed communication between macrophages and epithelial cells, endothelial cells, fibroblasts, and stem or tissue progenitor cells all contributing to a state of persistent injury, which may lead to the development of pathological fibrosis. In this review, we discuss the mechanisms that instruct macrophages to adopt pro-inflammatory, pro-wound healing, pro-fibrotic, anti-inflammatory, anti-fibrotic, pro-resolving, and tissue regenerating phenotypes following injury, and highlight how some of these mechanisms and macrophage activation states could be exploited therapeutically. PMID:26982353

Colonic macrophage polarization in homeostasis, inflammation, and cancer

PubMed Central

Appleyard, Caroline B.

2016-01-01

Our review focuses on the colonic macrophage, a monocyte-derived, tissue-resident macrophage, and the role it plays in health and disease, specifically in inflammatory conditions such as inflammatory bowel disease and cancer of the colon and rectum. We give special emphasis to macrophage polarization, or phenotype, in these different states. We focus on macrophages because they are one of the most numerous leukocytes in the colon, and because they normally contribute to homeostasis through an anti-inflammatory phenotype. However, in conditions such as inflammatory bowel disease, proinflammatory macrophages are increased in the colon and have been linked to disease severity and progression. In colorectal cancer, tumor cells may employ anti-inflammatory macrophages to promote tumor growth and dissemination, whereas proinflammatory macrophages may antagonize tumor growth. Given the key roles that this cell type plays in homeostasis, inflammation, and cancer, the colonic macrophage is an intriguing therapeutic target. As such, potential macrophage-targeting strategies are discussed. PMID:27229123

Isolation and Phenotyping of Intestinal Macrophages.

PubMed

Petit, Vanessa

2018-01-01

Macrophages are one of the most abundant leucocytes in the intestinal mucosa where they are essential for maintaining homeostasis. However they are also implicated in the pathogenesis of disorders such as inflammatory bowel disease (IBD), offering potential targets for novel therapies.Tissue macrophages are a heterogeneous population of immune cells that fulfill tissue-specific and niche-specific functions. These unique phenotypes likely reflect the heterogeneity of tissue macrophage origins and influence the tissue environment in which they reside. Here we describe how we can characterize and isolate the colonic macrophages.

Macrophages and the Viral Dissemination Super Highway

PubMed Central

Klepper, Arielle; Branch, Andrea D

2016-01-01

Monocytes and macrophages are key components of the innate immune system yet they are often the victims of attack by infectious agents. This review examines the significance of viral infection of macrophages. The central hypothesis is that macrophage tropism enhances viral dissemination and persistence, but these changes may come at the cost of reduced replication in cells other than macrophages. PMID:26949751

Overexpression of IL-10 in C2D macrophages promotes a macrophage phenotypic switch in adipose tissue environments.

PubMed

Xie, Linglin; Fu, Qiang; Ortega, Teresa M; Zhou, Lun; Rasmussen, Dane; O'Keefe, Jacy; Zhang, Ke K; Chapes, Stephen K

2014-01-01

Adipose tissue macrophages are a heterogeneous collection of classically activated (M1) and alternatively activated (M2) macrophages. Interleukin 10 (IL-10) is an anti-inflammatory cytokine, secreted by a variety of cell types including M2 macrophages. We generated a macrophage cell line stably overexpressing IL-10 (C2D-IL10) and analyzed the C2D-IL10 cells for several macrophage markers after exposure to adipocytes compared to C2D cells transfected with an empty vector (C2D-vector). C2D-IL10 macrophage cells expressed more CD206 when co-cultured with adipocytes than C2D-vector cells; while the co-cultured cell mixture also expressed higher levels of Il4, Il10, Il1β and Tnf. Since regular C2D cells traffic to adipose tissue after adoptive transfer, we explored the impact of constitutive IL-10 expression on C2D-IL10 macrophages in adipose tissue in vivo. Adipose tissue-isolated C2D-IL10 cells increased the percentage of CD206(+), CD301(+), CD11c(-)CD206(+) (M2) and CD11c(+)CD206(+) (M1b) on their cell surface, compared to isolated C2D-vector cells. These data suggest that the expression of IL-10 remains stable, alters the C2D-IL10 macrophage cell surface phenotype and may play a role in regulating macrophage interactions with the adipose tissue.

Macrophage Mitochondrial Oxidative Stress Promotes Atherosclerosis and NF-κB-Mediated Inflammation in Macrophages

PubMed Central

Wang, Ying; Wang, Gary Z.; Rabinovitch, Peter S.; Tabas, Ira

2014-01-01

Rationale Mitochondrial oxidative stress (mitoOS) has been shown to correlate with the progression of human atherosclerosis. However, definitive cell-type specific causation studies in vivo are lacking, and the molecular mechanisms of potential pro-atherogenic effects remain to be determined. Objective To assess the importance of macrophage mitoOS in atherogenesis and explore the underlying molecular mechanisms. Methods & Results We first validated Western-type diet-fed Ldlr-/- mice as a model of human mitoOS-atherosclerosis association by showing that a marker of mitoOS in lesional macrophages, non-nuclear oxidative DNA damage, correlates with aortic root lesion development. To investigate the importance of macrophage-mitoOS, we used a genetic engineering strategy in which the OS suppressor catalase was ectopically expressed in mitochondria (mCAT) in macrophages. MitoOS in lesional macrophages was successfully suppressed in these mice, and this led to a significant reduction in aortic root lesional area. The mCAT lesions had less monocyte-derived cells, less Ly6chi monocyte infiltration into lesions, and lower levels of the monocyte chemotactic protein-1 (MCP-1). The decrease in lesional MCP-1 was associated with suppression of other markers of inflammation and with decreased phosphorylation of RelA (NF-κB p65), indicating decreased activation of the pro-inflammatory NF-κB pathway. Using models of mitoOS in cultured macrophages, we showed that mCAT suppressed MCP-1 expression by decreasing activation of the Iκ-kinase-RelA NF-κB pathway. Conclusions MitoOS in lesional macrophages amplifies atherosclerotic lesion development by promoting NF-κB-mediated entry of monocytes and other inflammatory processes. In view of the mitoOS-atherosclerosis link in human atheromata, these findings reveal a potentially new therapeutic target to prevent the progression of atherosclerosis. PMID:24297735

Burkholderia cenocepacia Induces Macropinocytosis to Enter Macrophages.

PubMed

Rosales-Reyes, Roberto; Sánchez-Gómez, Concepción; Ortiz-Navarrete, Vianney; Santos-Preciado, José Ignacio

2018-01-01

Burkholderia cenocepacia is an opportunistic pathogen that infects individuals with cystic fibrosis, chronic granulomatous disease, and other immunocompromised states. B. cenocepacia survives in macrophages in membrane-bound vacuoles; however, the mechanism by which B. cenocepacia gains entry into macrophages remains unknown. After macrophage internalization, survival of B. cenocepacia within a bacteria-containing membrane vacuole (BcCV) is associated with its ability to arrest the maturation of the BcCV. In this study, we show that B. cenocepacia induces localized membrane ruffling, macropinocytosis, and macropinosomes-like compartments upon contact with the macrophage. The Type 3 Secretion System (T3SS) of B. cenocepacia contributes to macrophage entry and macropinosome-like compartment formation. These data demonstrate the ability of Burkholderia to enter macrophages through the induction of macropinocytosis.

Immunostimulatory effect of spinach aqueous extract on mouse macrophage-like J774.1 cells and mouse primary peritoneal macrophages.

PubMed

Ishida, Momoko; Ose, Saya; Nishi, Kosuke; Sugahara, Takuya

2016-07-01

We herein report the immunostimulatory effect of spinach aqueous extract (SAE) on mouse macrophage-like J774.1 cells and mouse primary peritoneal macrophages. SAE significantly enhanced the production of interleukin (IL)-6 and tumor necrosis factor-α by both J774.1 cells and peritoneal macrophages by enhancing the expression levels of these cytokine genes. In addition, the phagocytosis activity of J774.1 cells was facilitated by SAE. Immunoblot analysis revealed that SAE activates mitogen-activated protein kinase and nuclear factor-κB cascades. It was found that SAE activates macrophages through not only TLR4, but also other receptors. The production of IL-6 was significantly enhanced by peritoneal macrophages from SAE-administered BALB/c mice, suggesting that SAE has a potential to stimulate macrophage activity in vivo. Taken together, these data indicate that SAE would be a beneficial functional food with immunostimulatory effects on macrophages.

Effect of lipopolysaccharide on protein accumulation by murine peritoneal macrophages: the correlation to activation for macrophage tumoricidal function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tannenbaum, C.S.

1987-01-01

The protein synthetic patterns of tumoricidal murine peritoneal macrophage populations have been compared to those of non-tumoricidal populations utilizing two dimensional polyacrylamide gel electrophoresis (2D PAGE) of (/sup 35/S)-methionine-labeled proteins. While the protein synthetic patterns exhibited by resident, inflammatory and activated macrophages had numerous common features which distinguished them from the other normal non-macrophage cell types examined, unique proteins also distinguished each macrophage population from the others. Peritoneal macrophages elicited by treatment with heat killed Propionibacterium acnes, the live, attenuated Mycobacterium bovis strain BCG, Listeria monocytogenes and the protozoan flagellate Trypanosoma rhodesiense, all exhibited tumoricidal activity in 16h or 72hmore » functional assays, and shared a common protein synthetic profile which differentiated them from the synthetic patterns characteristic of the non-tumoricidal resident and inflammatory macrophages.« less

45 CFR 1611.9 - Retainer agreements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 4 2014-10-01 2014-10-01 false Retainer agreements. 1611.9 Section 1611.9 Public... ELIGIBILITY § 1611.9 Retainer agreements. (a) When a recipient provides extended service to a client, the recipient shall execute a written retainer agreement with the client. The retainer agreement shall be...

Activation by nitric oxide of an oxidative-stress response that defends Escherichia coli against activated macrophages.

PubMed Central

Nunoshiba, T; deRojas-Walker, T; Wishnok, J S; Tannenbaum, S R; Demple, B

1993-01-01

Nitric oxide is a free radical (NO) formed biologically through the oxidation of L-arginine by nitric oxide synthases. NO is produced transiently in mammalian cells for intercellular signaling and in copious quantities to cause cytostasis and cytotoxicity. In the latter situation, NO is a deliberate cytotoxic product of activated macrophages, along with other reactive oxygen species such as hydrogen peroxide (H2O2) and superoxide (O2-). Escherichia coli has a complex set of responses to H2O2 and O2- that involves approximately 80 inducible proteins; we wondered whether these bacteria might induce analogous defenses against nitric oxide. We show here that a multigene system controlled by the redox-sensitive transcriptional regulator SoxR is activated by NO in vivo. This induction confers bacterial resistance to activated murine macrophages with kinetics that parallel the production of NO by these cells. Elimination of specific SoxR-regulated genes diminishes the resistance of these bacteria to the cytotoxic macrophages. The required functions include manganese-containing superoxide dismutase, endonuclease IV (a DNA-repair enzyme for oxidative damage), and micF, an antisense regulator of the outer membrane porin OmpF. These results demonstrate that SoxR is a sensor for cellular exposure to NO, and that the soxRS response system may contribute to bacterial virulence. PMID:8234347

The transcriptome of Legionella pneumophila-infected human monocyte-derived macrophages.

PubMed

Price, Christopher T D; Abu Kwaik, Yousef

2014-01-01

Legionella pneumophila is an intracellular bacterial pathogen that invades and replicates within alveolar macrophages through injection of ∼ 300 effector proteins by its Dot/Icm type IV translocation apparatus. The bona fide F-box protein, AnkB, is a nutritional virulence effector that triggers macrophages to generate a surplus of amino acids, which is essential for intravacuolar proliferation. Therefore, the ankB mutant represents a novel genetic tool to determine the transcriptional response of human monocyte-derived macrophages (hMDMs) to actively replicating L. pneumophila. Here, we utilized total human gene microarrays to determine the global transcriptional response of hMDMs to infection by wild type or the ankB mutant of L. pneumophila. The transcriptomes of hMDMs infected with either actively proliferating wild type or non-replicative ankB mutant bacteria were remarkably similar. The transcriptome of infected hMDMs was predominated by up-regulation of inflammatory pathways (IL-10 anti-inflammatory, interferon signaling and amphoterin signaling), anti-apoptosis, and down-regulation of protein synthesis pathways. In addition, L. pneumophila modulated diverse metabolic pathways, particularly those associated with bio-active lipid metabolism, and SLC amino acid transporters expression. Taken together, the hMDM transcriptional response to L. pneumophila is independent of intra-vacuolar replication of the bacteria and primarily involves modulation of the immune response and metabolic as well as nutritional pathways.

Celastrol nanomicelles attenuate cytokine secretion in macrophages and inhibit macrophage-induced corneal neovascularization in rats.

PubMed

Li, Zhanrong; Li, Jingguo; Zhu, Lei; Zhang, Ying; Zhang, Junjie; Yao, Lin; Liang, Dan; Wang, Liya

The aim of the present study was to investigate the inhibitory effects of celastrol-loaded nanomicelles (CNMs) on activated macrophage-induced corneal neovascularization (CNV) in rats and cytokine secretion in macrophages. Using an angiogenesis assay in vitro, we detected the effects of CNMs on human umbilical vein endothelial cell (HUVEC) migration and invasion. In addition, the expression levels of cytokines secreted from hypoxia-induced macrophages were assessed through cytokine array analysis. The expression of hypoxia-inducible factors-1α (HIF-1α), nuclear factor-kappa B p65 (NF-κB p65), phospho-nuclear factor-kappa B p65 (phospho-NF-κB p65), p38 mitogen-activated protein kinase (p38 MAPK), phospho-p38 MAPK, extracellular signal-regulated kinase 1/2 (ERK1/2), and phospho-ERK1/2 was analyzed by western blotting. Activated macrophages were elicited through mineral oil lumbar injection, labeled with 1,19-dioctadecyl-3-3-39,39-tetramethylindocarbocyanine (DiI) and implanted into the corneal micro-pocket to induce CNV and to assess the antiangiogenic effect in rats. CNV was morphometrically analyzed using ImageJ software. Histopathological features were evaluated by immunofluorescence immunostaining for vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) on day 2 after surgery. In the present study, the results indicated that CNMs significantly inhibited the migration and invasion of HUVECs; remarkably attenuated the expression of VEGF, tumor necrosis factor-α, interleukin-1α, monocyte chemoattractant protein 1, cytokine-induced neutrophil chemoattractant 3, and MMP-9 protein; and downregulated ERK1/2, p38 MAPK, NF-κB activation, and HIF-1α expression in macrophages. The peritoneal cells elicited using mineral oil were highly purified macrophages, and the length and area of CNV were significantly decreased in the CNMs group compared with the control group. There was a significant reduction in the expression of VEGF and MMP-9 in

Enhanced performance of macrophage-encapsulated nanoparticle albumin-bound-paclitaxel in hypo-perfused cancer lesions

NASA Astrophysics Data System (ADS)

Leonard, Fransisca; Curtis, Louis T.; Yesantharao, Pooja; Tanei, Tomonori; Alexander, Jenolyn F.; Wu, Min; Lowengrub, John; Liu, Xuewu; Ferrari, Mauro; Yokoi, Kenji; Frieboes, Hermann B.; Godin, Biana

2016-06-01

impaired transport of both low- and high-molecular weight drugs into the lesions and to high washout rate. Nanoparticle albumin-bound-paclitaxel (nAb-PTX) has demonstrated benefits in clinical trials when compared to paclitaxel and docetaxel. However, its therapeutic efficacy for breast cancer liver metastasis is disappointing. As macrophages are the most abundant cells in the liver tumor microenvironment, we design a multistage system employing macrophages to deliver drugs into hypovascularized metastatic lesions, and perform in vitro, in vivo, and in silico evaluation. The system encapsulates nAb-PTX into nanoporous biocompatible and biodegradable multistage vectors (MSV), thus promoting nAb-PTX retention in macrophages. We develop a 3D in vitro model to simulate clinically observed hypo-perfused tumor lesions surrounded by macrophages. This model enables evaluation of nAb-PTX and MSV-nab PTX efficacy as a function of transport barriers. Addition of macrophages to this system significantly increases MSV-nAb-PTX efficacy, revealing the role of macrophages in drug transport. In the in vivo model, a significant increase in macrophage number, as compared to unaffected liver, is observed in mice, confirming the in vitro findings. Further, a mathematical model linking drug release and retention from macrophages is implemented to project MSV-nAb-PTX efficacy in a clinical setting. Based on macrophage presence detected via liver tumor imaging and biopsy, the proposed experimental/computational approach could enable prediction of MSV-nab PTX performance to treat metastatic cancer in the liver. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07796f

M2 Macrophages Play Critical Roles in Progression of Inflammatory Liver Disease in Hepatitis C Virus Transgenic Mice.

PubMed

Ohtsuki, Takahiro; Kimura, Kiminori; Tokunaga, Yuko; Tsukiyama-Kohara, Kyoko; Tateno, Chise; Hayashi, Yukiko; Hishima, Tsunekazu; Kohara, Michinori

2016-01-01

Macrophages in liver tissue are widely defined as important inflammatory cells in chronic viral hepatitis due to their proinflammatory activity. We reported previously that interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) play significant roles in causing chronic hepatitis in hepatitis C virus (HCV) transgenic mice (S. Sekiguchi et al., PLoS One 7:e51656, 2012, http://dx.doi.org/10.1371/journal.pone.0051656). In addition, we showed that recombinant vaccinia viruses expressing an HCV nonstructural protein (rVV-N25) could protect against the progression of chronic hepatitis by suppression of macrophage activation. Here, we focus on the role of macrophages in liver disease progression in HCV transgenic mice and examine characteristic features of macrophages following rVV-N25 treatment. The number of CD11b(+) F4/80(+) CD11c(-) CD206(+) (M2) macrophages in the liver of HCV transgenic mice was notably increased compared to that of age-matched control mice. These M2 macrophages in the liver produced elevated levels of IL-6 and TNF-α. rVV-N25 infection suppressed the number and activation of M2 macrophages in liver tissue. These results suggested that inflammatory cytokines produced by M2-like macrophages contribute to the induction of chronic liver inflammation in HCV transgenic mice. Moreover, the therapeutic effect of rVV-N25 might be induced by the suppression of the number and activation of hepatic macrophages. HCV causes persistent infections that can lead to chronic liver diseases, liver fibrosis, and hepatocellular carcinoma; the search for an HCV curative is the focus of ongoing research. Recently, effective anti-HCV drugs have been developed; however, vaccine development still is required for the prevention and therapy of infection by this virus. We demonstrate here that M2 macrophages are important for the pathogenesis of HCV-caused liver diseases and additionally show that M2 macrophages contribute to the therapeutic mechanism observed following r

M2 Macrophages Play Critical Roles in Progression of Inflammatory Liver Disease in Hepatitis C Virus Transgenic Mice

PubMed Central

Ohtsuki, Takahiro; Kimura, Kiminori; Tokunaga, Yuko; Tsukiyama-Kohara, Kyoko; Tateno, Chise; Hayashi, Yukiko; Hishima, Tsunekazu

2015-01-01

ABSTRACT Macrophages in liver tissue are widely defined as important inflammatory cells in chronic viral hepatitis due to their proinflammatory activity. We reported previously that interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) play significant roles in causing chronic hepatitis in hepatitis C virus (HCV) transgenic mice (S. Sekiguchi et al., PLoS One 7:e51656, 2012, http://dx.doi.org/10.1371/journal.pone.0051656). In addition, we showed that recombinant vaccinia viruses expressing an HCV nonstructural protein (rVV-N25) could protect against the progression of chronic hepatitis by suppression of macrophage activation. Here, we focus on the role of macrophages in liver disease progression in HCV transgenic mice and examine characteristic features of macrophages following rVV-N25 treatment. The number of CD11b+ F4/80+ CD11c− CD206+ (M2) macrophages in the liver of HCV transgenic mice was notably increased compared to that of age-matched control mice. These M2 macrophages in the liver produced elevated levels of IL-6 and TNF-α. rVV-N25 infection suppressed the number and activation of M2 macrophages in liver tissue. These results suggested that inflammatory cytokines produced by M2-like macrophages contribute to the induction of chronic liver inflammation in HCV transgenic mice. Moreover, the therapeutic effect of rVV-N25 might be induced by the suppression of the number and activation of hepatic macrophages. IMPORTANCE HCV causes persistent infections that can lead to chronic liver diseases, liver fibrosis, and hepatocellular carcinoma; the search for an HCV curative is the focus of ongoing research. Recently, effective anti-HCV drugs have been developed; however, vaccine development still is required for the prevention and therapy of infection by this virus. We demonstrate here that M2 macrophages are important for the pathogenesis of HCV-caused liver diseases and additionally show that M2 macrophages contribute to the therapeutic mechanism

Nontransformed, GM-CSF-dependent macrophage lines are a unique model to study tissue macrophage functions.

PubMed

Fejer, György; Wegner, Mareike Dorothee; Györy, Ildiko; Cohen, Idan; Engelhard, Peggy; Voronov, Elena; Manke, Thomas; Ruzsics, Zsolt; Dölken, Lars; Prazeres da Costa, Olivia; Branzk, Nora; Huber, Michael; Prasse, Antje; Schneider, Robert; Apte, Ron N; Galanos, Chris; Freudenberg, Marina A

2013-06-11

Macrophages are diverse cell types in the first line of antimicrobial defense. Only a limited number of primary mouse models exist to study their function. Bone marrow-derived, macrophage-CSF-induced cells with a limited life span are the most common source. We report here a simple method yielding self-renewing, nontransformed, GM-CSF/signal transducer and activator of transcription 5-dependent macrophages (Max Planck Institute cells) from mouse fetal liver, which reflect the innate immune characteristics of alveolar macrophages. Max Planck Institute cells are exquisitely sensitive to selected microbial agents, including bacterial LPS, lipopeptide, Mycobacterium tuberculosis, cord factor, and adenovirus and mount highly proinflammatory but no anti-inflammatory IL-10 responses. They show a unique pattern of innate responses not yet observed in other mononuclear phagocytes. This includes differential LPS sensing and an unprecedented regulation of IL-1α production upon LPS exposure, which likely plays a key role in lung inflammation in vivo. In conclusion, Max Planck Institute cells offer an useful tool to study macrophage biology and for biomedical science.

Phagocytosis imprints heterogeneity in tissue-resident macrophages

PubMed Central

A-Gonzalez, Noelia; Quintana, Juan A.; Mazariegos, Marina; González de la Aleja, Arturo; Nicolás-Ávila, José A.; Crainiciuc, Georgiana; Rothlin, Carla V.; Peinado, Héctor; Castrillo, Antonio

2017-01-01

Tissue-resident macrophages display varying phenotypic and functional properties that are largely specified by their local environment. One of these functions, phagocytosis, mediates the natural disposal of billions of cells, but its mechanisms and consequences within living tissues are poorly defined. Using a parabiosis-based strategy, we identified and isolated macrophages from multiple tissues as they phagocytosed blood-borne cellular material. Phagocytosis was circadianally regulated and mediated by distinct repertoires of receptors, opsonins, and transcription factors in macrophages from each tissue. Although the tissue of residence defined the core signature of macrophages, phagocytosis imprinted a distinct antiinflammatory profile. Phagocytic macrophages expressed CD206, displayed blunted expression of Il1b, and supported tissue homeostasis. Thus, phagocytosis is a source of macrophage heterogeneity that acts together with tissue-derived factors to preserve homeostasis. PMID:28432199

Burkholderia cenocepacia Induces Macropinocytosis to Enter Macrophages

PubMed Central

2018-01-01

Burkholderia cenocepacia is an opportunistic pathogen that infects individuals with cystic fibrosis, chronic granulomatous disease, and other immunocompromised states. B. cenocepacia survives in macrophages in membrane-bound vacuoles; however, the mechanism by which B. cenocepacia gains entry into macrophages remains unknown. After macrophage internalization, survival of B. cenocepacia within a bacteria-containing membrane vacuole (BcCV) is associated with its ability to arrest the maturation of the BcCV. In this study, we show that B. cenocepacia induces localized membrane ruffling, macropinocytosis, and macropinosomes-like compartments upon contact with the macrophage. The Type 3 Secretion System (T3SS) of B. cenocepacia contributes to macrophage entry and macropinosome-like compartment formation. These data demonstrate the ability of Burkholderia to enter macrophages through the induction of macropinocytosis. PMID:29850514

Redox Control of Inflammation in Macrophages

PubMed Central

Dehne, Nathalie; Grossmann, Nina; Jung, Michaela; Namgaladze, Dmitry; Schmid, Tobias; von Knethen, Andreas; Weigert, Andreas

2013-01-01

Abstract Macrophages are present throughout the human body, constitute important immune effector cells, and have variable roles in a great number of pathological, but also physiological, settings. It is apparent that macrophages need to adjust their activation profile toward a steadily changing environment that requires altering their phenotype, a process known as macrophage polarization. Formation of reactive oxygen species (ROS), derived from NADPH-oxidases, mitochondria, or NO-producing enzymes, are not necessarily toxic, but rather compose a network signaling system, known as redox regulation. Formation of redox signals in classically versus alternatively activated macrophages, their action and interaction at the level of key targets, and the resulting physiology still are insufficiently understood. We review the identity, source, and biological activities of ROS produced during macrophage activation, and discuss how they shape the key transcriptional responses evoked by hypoxia-inducible transcription factors, nuclear-erythroid 2-p45-related factor 2 (Nrf2), and peroxisome proliferator-activated receptor-γ. We summarize the mechanisms how redox signals add to the process of macrophage polarization and reprogramming, how this is controlled by the interaction of macrophages with their environment, and addresses the outcome of the polarization process in health and disease. Future studies need to tackle the option whether we can use the knowledge of redox biology in macrophages to shape their mediator profile in pathophysiology, to accelerate healing in injured tissue, to fight the invading pathogens, or to eliminate settings of altered self in tumors. Antioxid. Redox Signal. 19, 595–637. PMID:23311665

Spin bearing retainer design optimization

NASA Technical Reports Server (NTRS)

Boesiger, Edward A.; Warner, Mark H.

1991-01-01

The dynamics behavior of spin bearings for momentum wheels (control-moment gyroscope, reaction wheel assembly) is critical to satellite stability and life. Repeated bearing retainer instabilities hasten lubricant deterioration and can lead to premature bearing failure and/or unacceptable vibration. These instabilities are typically distinguished by increases in torque, temperature, audible noise, and vibration induced by increases into the bearing cartridge. Ball retainer design can be optimized to minimize these occurrences. A retainer was designed using a previously successful smaller retainer as an example. Analytical methods were then employed to predict its behavior and optimize its configuration.

STATs and macrophage fusion.

PubMed

Miyamoto, Takeshi

2013-07-01

Macrophages play a pivotal role in host defense against multiple foreign materials such as bacteria, parasites and artificial devices. Some macrophage lineage cells, namely osteoclasts and foreign body giant cells (FBGCs), form multi-nuclear giant cells by the cell-cell fusion of mono-nuclear cells. Osteoclasts are bone-resorbing cells, and are formed in the presence of RANKL on the surface of bones, while FBGCs are formed in the presence of IL-4 or IL-13 on foreign materials such as artificial joints, catheters and parasites. Recently, fusiogenic mechanisms and the molecules required for the cell-cell fusion of these macrophage lineage cells were, at least in part, clarified. Dendritic cell specific transmembrane protein (DC-STAMP) and osteoclast stimulatory transmembrane protein (OC-STAMP), both of which comprise seven transmembrane domains, are required for both osteoclast and FBGC cell-cell fusion. STAT6 was demonstrated to be required for the cell-cell fusion of FBGCs but not osteoclasts. In this review, advances in macrophage cell-cell fusion are discussed.

Macrophage activation by glycoprotein isolated from Dioscorea batatas

PubMed Central

Huong, Pham Thi Thu

2011-01-01

We demonstrate that glycoprotein isolated from Dioscorea batatas (GDB) activates macrophage function. Analysis of the infiltration of macrophages into peritoneal cavity showed GDB treatment significantly increased the recruitment of macrophages into the peritoneal cavity. In order to further confirm and investigate the mechanism of GDB on macrophage activation, we analyzed the effects of GDB on the cytokine expression including IL-1β, TNF-α, and IL-6 in mouse peritoneal macrophages. GDB increased the expression of IL-1β, TNF-α, and IL-6. Cytokine induction by GDB was further confirmed by RT-PCR and ELISA in mouse macrophage cell line, RAW264.7 cells. Treatment of RAW264.7 cells with GDB produced strong induction of NF-κB DNA binding and MAPK phosphorylation, markers for macrophage activation and important factors for cytokine gene expression. Collectively, this series of experiments indicates that GDB stimulates macrophage activation. PMID:24278568

Apoptosis inhibitor of macrophage depletion decreased M1 macrophage accumulation and the incidence of cardiac rupture after myocardial infarction in mice.

PubMed

Ishikawa, Shohei; Noma, Takahisa; Fu, Hai Ying; Matsuzaki, Takashi; Ishizawa, Makoto; Ishikawa, Kaori; Murakami, Kazushi; Nishimoto, Naoki; Nishiyama, Akira; Minamino, Tetsuo

2017-01-01

Cardiac rupture is an important cause of death in the acute phase after myocardial infarction (MI). Macrophages play a pivotal role in cardiac remodeling after MI. Apoptosis inhibitor of macrophage (AIM) is secreted specifically by macrophages and contributes to macrophage accumulation in inflamed tissue by maintaining survival and recruiting macrophages. In this study, we evaluated the role of AIM in macrophage accumulation in the infarcted myocardium and cardiac rupture after MI. Wild-type (WT) and AIM‒/‒ mice underwent permanent left coronary artery ligation and were followed-up for 7 days. Macrophage accumulation and phenotypes (M1 pro-inflammatory macrophage or M2 anti-inflammatory macrophage) were evaluated by immunohistological analysis and RT-PCR. Matrix metalloproteinase (MMP) activity levels were measured by gelatin zymography. The survival rate was significantly higher (81.1% vs. 48.2%, P<0.05), and the cardiac rupture rate was significantly lower in AIM‒/‒ mice than in WT mice (10.8% vs. 31.5%, P<0.05). The number of M1 macrophages and the expression levels of M1 markers (iNOS and IL-6) in the infarcted myocardium were significantly lower in AIM‒/‒ mice than in WT mice. In contrast, there was no difference in the number of M2 macrophages and the expression of M2 markers (Arg-1, CD206 and TGF-β1) between the two groups. The ratio of apoptotic macrophages in the total macrophages was significantly higher in AIM‒/‒ mice than in WT mice, although MCP-1 expression did not differ between the two groups. MMP-2 and 9 activity levels in the infarcted myocardium were significantly lower in AIM‒/‒ mice than in WT mice. These findings suggest that AIM depletion decreases the levels of M1 macrophages, which are a potent source of MMP-2 and 9, in the infarcted myocardium in the acute phase after MI by promoting macrophage apoptosis, and leads to a decrease in the incidence of cardiac rupture and improvements in survival rates.

Apoptosis inhibitor of macrophage depletion decreased M1 macrophage accumulation and the incidence of cardiac rupture after myocardial infarction in mice

PubMed Central

Noma, Takahisa; Fu, Hai Ying; Matsuzaki, Takashi; Ishizawa, Makoto; Ishikawa, Kaori; Murakami, Kazushi; Nishimoto, Naoki; Nishiyama, Akira; Minamino, Tetsuo

2017-01-01

Background Cardiac rupture is an important cause of death in the acute phase after myocardial infarction (MI). Macrophages play a pivotal role in cardiac remodeling after MI. Apoptosis inhibitor of macrophage (AIM) is secreted specifically by macrophages and contributes to macrophage accumulation in inflamed tissue by maintaining survival and recruiting macrophages. In this study, we evaluated the role of AIM in macrophage accumulation in the infarcted myocardium and cardiac rupture after MI. Methods and results Wild-type (WT) and AIM‒/‒ mice underwent permanent left coronary artery ligation and were followed-up for 7 days. Macrophage accumulation and phenotypes (M1 pro-inflammatory macrophage or M2 anti-inflammatory macrophage) were evaluated by immunohistological analysis and RT-PCR. Matrix metalloproteinase (MMP) activity levels were measured by gelatin zymography. The survival rate was significantly higher (81.1% vs. 48.2%, P<0.05), and the cardiac rupture rate was significantly lower in AIM‒/‒ mice than in WT mice (10.8% vs. 31.5%, P<0.05). The number of M1 macrophages and the expression levels of M1 markers (iNOS and IL-6) in the infarcted myocardium were significantly lower in AIM‒/‒ mice than in WT mice. In contrast, there was no difference in the number of M2 macrophages and the expression of M2 markers (Arg-1, CD206 and TGF-β1) between the two groups. The ratio of apoptotic macrophages in the total macrophages was significantly higher in AIM‒/‒ mice than in WT mice, although MCP-1 expression did not differ between the two groups. MMP-2 and 9 activity levels in the infarcted myocardium were significantly lower in AIM‒/‒ mice than in WT mice. Conclusions These findings suggest that AIM depletion decreases the levels of M1 macrophages, which are a potent source of MMP-2 and 9, in the infarcted myocardium in the acute phase after MI by promoting macrophage apoptosis, and leads to a decrease in the incidence of cardiac rupture and

Apoptosis inhibitor of macrophage (AIM) is required for obesity-associated recruitment of inflammatory macrophages into adipose tissue

PubMed Central

Kurokawa, Jun; Nagano, Hiromichi; Ohara, Osamu; Kubota, Naoto; Kadowaki, Takashi; Arai, Satoko; Miyazaki, Toru

2011-01-01

Infiltration of inflammatory macrophages into adipose tissues with the progression of obesity triggers insulin resistance and obesity-related metabolic diseases. We recently reported that macrophage-derived apoptosis inhibitor of macrophage (AIM) protein is increased in blood in line with obesity progression and is incorporated into adipocytes, thereby inducing lipolysis in adipose tissue. Here we show that such a response is required for the recruitment of adipose tissue macrophages. In vitro, AIM-dependent lipolysis induced an efflux of palmitic and stearic acids from 3T3-L1 adipocytes, thereby stimulating chemokine production in adipocytes via activation of toll-like receptor 4 (TLR4). In vivo administration of recombinant AIM to TLR4-deficient (TLR4−/−) mice resulted in induction of lipolysis without chemokine production in adipose tissues. Consistently, mRNA levels for the chemokines that affect macrophages were far lower in AIM-deficient (AIM−/−) than in wild-type (AIM+/+) obese adipose tissue. This reduction in chemokine production resulted in a marked prevention of inflammatory macrophage infiltration into adipose tissue in obese AIM−/− mice, although these mice showed more advanced obesity than AIM+/+ mice on a high-fat diet. Diminished macrophage infiltration resulted in decreased inflammation locally and systemically in obese AIM−/− mice, thereby protecting them from insulin resistance and glucose intolerance. These results indicate that the increase in blood AIM is a critical event for the initiation of macrophage recruitment into adipose tissue, which is followed by insulin resistance. Thus, AIM suppression might be therapeutically applicable for the prevention of obesity-related metabolic disorders. PMID:21730133

Induced-Pluripotent-Stem-Cell-Derived Primitive Macrophages Provide a Platform for Modeling Tissue-Resident Macrophage Differentiation and Function.

PubMed

Takata, Kazuyuki; Kozaki, Tatsuya; Lee, Christopher Zhe Wei; Thion, Morgane Sonia; Otsuka, Masayuki; Lim, Shawn; Utami, Kagistia Hana; Fidan, Kerem; Park, Dong Shin; Malleret, Benoit; Chakarov, Svetoslav; See, Peter; Low, Donovan; Low, Gillian; Garcia-Miralles, Marta; Zeng, Ruizhu; Zhang, Jinqiu; Goh, Chi Ching; Gul, Ahmet; Hubert, Sandra; Lee, Bernett; Chen, Jinmiao; Low, Ivy; Shadan, Nurhidaya Binte; Lum, Josephine; Wei, Tay Seok; Mok, Esther; Kawanishi, Shohei; Kitamura, Yoshihisa; Larbi, Anis; Poidinger, Michael; Renia, Laurent; Ng, Lai Guan; Wolf, Yochai; Jung, Steffen; Önder, Tamer; Newell, Evan; Huber, Tara; Ashihara, Eishi; Garel, Sonia; Pouladi, Mahmoud A; Ginhoux, Florent

2017-07-18

Tissue macrophages arise during embryogenesis from yolk-sac (YS) progenitors that give rise to primitive YS macrophages. Until recently, it has been impossible to isolate or derive sufficient numbers of YS-derived macrophages for further study, but data now suggest that induced pluripotent stem cells (iPSCs) can be driven to undergo a process reminiscent of YS-hematopoiesis in vitro. We asked whether iPSC-derived primitive macrophages (iMacs) can terminally differentiate into specialized macrophages with the help of growth factors and organ-specific cues. Co-culturing human or murine iMacs with iPSC-derived neurons promoted differentiation into microglia-like cells in vitro. Furthermore, murine iMacs differentiated in vivo into microglia after injection into the brain and into functional alveolar macrophages after engraftment in the lung. Finally, iPSCs from a patient with familial Mediterranean fever differentiated into iMacs with pro-inflammatory characteristics, mimicking the disease phenotype. Altogether, iMacs constitute a source of tissue-resident macrophage precursors that can be used for biological, pathophysiological, and therapeutic studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Mitogen-activated protein kinase phosphatase-1 expression in macrophages is controlled by lymphocytes during macrophage activation.

PubMed

Luo, Chong; Yang, Xiqiang; Yao, Lan; Jiang, Liping; Liu, Wei; Li, Xin; Wang, Lijia

2012-01-01

The viewpoints on the control of innate immune cells by the adaptive immune system during sepsis remain controversial. Mitogen-activated protein kinase phosphatase-1 (MKP-1) is essential to the negative control of innate immunity and suppresses the activation of macrophages by inhibiting activated mitogen-activated protein kinase (MAPK). The purpose of the current study was to observe inflammatory response and macrophage activation in mice with severe combined immunodeficiency (SCID) with endotoxemia and to determine the role of MKP-1 in the control of macrophage activation by the adaptive immune system. Endotoxemia was induced in wild-type and SCID mice by an intraperitoneal injection of lipopolysaccharide (LPS), and all of the SCID mice died. SCID mice produced more inflammatory cytokines than BALB/c mice systemically and locally. TNF-α mRNA expression was higher and MKP-1 mRNA expression was lower in peritoneal macrophages (PMa) from SCID mice compared to PMa from wild-type mice after and even before LPS injection. Thioglycollate-stimulated PMa from wild-type mice were stimulated with LPS in vitro in the presence or absence of pan-T cells. The levels of TNF-α and IL-6 were higher in the supernatants from PMa cultured alone compared to PMa co-cultured with pan-T cells, and PMa MKP-1 mRNA and protein expression were higher when PMa were co-cultured with pan-T cells. Therefore, pan-T cells can up-regulate MKP-1 expression in macrophages and inhibit the secretion of inflammatory cytokines secretion by macrophages. In SCID mice, lymphocyte deficiency, especially T cell deficiency, causes insufficient MKP-1 expression in macrophages, which can be responsible for the severe inflammation and bad prognosis of septic SCID mice. MKP-1 plays an important role in the control of macrophage activation by the adaptive immune system.

Disinhibition of Cathepsin C Caused by Cystatin F Deficiency Aggravates the Demyelination in a Cuprizone Model.

PubMed

Liang, Junjie; Li, Ning; Zhang, Yanli; Hou, Changyi; Yang, Xiaohan; Shimizu, Takahiro; Wang, Xiaoyu; Ikenaka, Kazuhiro; Fan, Kai; Ma, Jianmei

2016-01-01

Although the precise mechanism underlying initial lesion development in multiple sclerosis (MS) remains unclear, CNS inflammation has long been associated with demyelination, and axonal degeneration. The activation of microglia/macrophages, which serve as innate immune cells in the CNS, is the first reaction to even minor pathologic changes in the CNS and is considered an initial pathogenic event in MS. Microglial activation accompanies a variety of gene expressions, including cystatin F (Cys F), which belongs to the cystatin superfamily and is one of the cathepsin inhibitors. In our previous study we showed that Cys F has a unique expression pattern in microglia/macrophages in the demyelination process. Specifically, the timing of Cys F induction correlated with ongoing demyelination, and the sites of Cys F expression overlapped with areas of remyelination. Cys F induction ceased in chronic demyelination when remyelination capacity was lost, suggesting that Cys F expressed by microglia/macrophages may play an important role in demyelination and/or remyelination. The functional role of Cys F in demyelinating disease of the CNS, however, is unclear. Cys F gene knockout mice were used in the current study to clarify the functional role of Cys F in the demyelination process in a cuprizone-induced demyelination animal model. We demonstrated that absence of the Cys F gene and the resulting disinhibition of cathepsin C (Cat C) aggravates the demyelination, and this finding may be related to the increased expression of the glia-derived chemokine, CXCL2, which may attract inflammatory cells to sites of myelin sheath damage. This effect was reversed by knock down of the Cat C gene. The findings gain further insight to function of Cat C in pathophysiology of MS, which may have implications for therapeutics for the prevention of neuroinflammation-involved neurological disorders in the future.

Disinhibition of Cathepsin C Caused by Cystatin F Deficiency Aggravates the Demyelination in a Cuprizone Model

PubMed Central

Liang, Junjie; Li, Ning; Zhang, Yanli; Hou, Changyi; Yang, Xiaohan; Shimizu, Takahiro; Wang, Xiaoyu; Ikenaka, Kazuhiro; Fan, Kai; Ma, Jianmei

2016-01-01

Although the precise mechanism underlying initial lesion development in multiple sclerosis (MS) remains unclear, CNS inflammation has long been associated with demyelination, and axonal degeneration. The activation of microglia/macrophages, which serve as innate immune cells in the CNS, is the first reaction to even minor pathologic changes in the CNS and is considered an initial pathogenic event in MS. Microglial activation accompanies a variety of gene expressions, including cystatin F (Cys F), which belongs to the cystatin superfamily and is one of the cathepsin inhibitors. In our previous study we showed that Cys F has a unique expression pattern in microglia/macrophages in the demyelination process. Specifically, the timing of Cys F induction correlated with ongoing demyelination, and the sites of Cys F expression overlapped with areas of remyelination. Cys F induction ceased in chronic demyelination when remyelination capacity was lost, suggesting that Cys F expressed by microglia/macrophages may play an important role in demyelination and/or remyelination. The functional role of Cys F in demyelinating disease of the CNS, however, is unclear. Cys F gene knockout mice were used in the current study to clarify the functional role of Cys F in the demyelination process in a cuprizone-induced demyelination animal model. We demonstrated that absence of the Cys F gene and the resulting disinhibition of cathepsin C (Cat C) aggravates the demyelination, and this finding may be related to the increased expression of the glia-derived chemokine, CXCL2, which may attract inflammatory cells to sites of myelin sheath damage. This effect was reversed by knock down of the Cat C gene. The findings gain further insight to function of Cat C in pathophysiology of MS, which may have implications for therapeutics for the prevention of neuroinflammation-involved neurological disorders in the future. PMID:28066178

Monocyte to macrophage differentiation-associated (MMD) positively regulates ERK and Akt activation and TNF-α and NO production in macrophages.

PubMed

Liu, Qiang; Zheng, Jin; Yin, Dan-Dan; Xiang, Jie; He, Fei; Wang, Yao-Chun; Liang, Liang; Qin, Hong-Yan; Liu, Li; Liang, Ying-Min; Han, Hua

2012-05-01

Macrophage activation is modulated by both environmental cues and endogenous programs. In the present study, we investigated the role of a PAQR family protein, monocyte to macrophage differentiation-associated (MMD), in macrophage activation and unveiled its underlying molecular mechanism. Our results showed that while MMD expression could be detected in all tissues examined, its expression level is significantly up-regulated upon monocyte differentiation. Within cells, EGFP-MMD fusion protein could be co-localized to endoplasmic reticulum, mitochondria, Golgi apparatus, but not lysosomes and cytoplasm. MMD expression is up-regulated in macrophages after LPS stimulation, and this might be modulated by RBP-J, the critical transcription factor of Notch signaling. Overexpression of MMD in macrophages increased the production of TNF-α and NO upon LPS stimulation. We found that MMD overexpression enhanced ERK1/2 and Akt phosphorylation in macrophages after LPS stimulation. Blocking Erk or Akt by pharmacological agent reduced TNF-α or NO production in MMD-overexpressing macrophages, respectively. These results suggested that MMD modulates TNF-α and NO production in macrophages, and this process might involves Erk or Akt.

Inhibition of M1 macrophage activation in adipose tissue by berberine improves insulin resistance.

PubMed

Ye, Lifang; Liang, Shu; Guo, Chao; Yu, Xizhong; Zhao, Juan; Zhang, Hao; Shang, Wenbin

2016-12-01

Insulin resistance is associated with a chronic inflammation in adipose tissue which is propagated by a phenotypic switch in adipose tissue macrophage (ATM) polarization. This study aimed to investigate whether berberine, the major alkaloid of rhizoma coptidis, can improve insulin resistance through inhibiting ATM activation and inflammatory response in adipose tissue. High-fat-diet induced obese mice were administered oral with berberine (50mg/kg/day) for 14days. ATMs were analysed using FACS and insulin resistance was evaluated. Expressions of pro-inflammatory cytokines and activation of inflammatory pathways were detected. The chemotaxis of macrophages was measured. Glucose consumption and insulin signalling of adipocytes were examined. Berberine significantly decreased F4/80 + /CD11c + /CD206 - cells in the stromal vascular fraction from adipose tissue and improved glucose tolerance in obsess mice. In addition, berberine reduced the elevated levels of serum TNF-α, IL-6 and MCP-1 and the expressions of TNF-α, IL-6 and MCP-1 and attenuated the phosphorylation of JNK and IKKβ and the expression of NF-κB p65 in the obese adipose tissue, Raw264.7 macrophages and 3T3-L1 adipocytes, respectively. The phosphorylation of IRS-1 (Ser307) was inhibited by berberine in adipose tissue and cultured adipocytes. The phosphorylation of AKT (Ser473) was increased in berberine-treated adipose tissue. Conditioned medium from adipocytes treated with berberine reduced the number of infiltrated macrophages. Berberine partly restored the impaired glucose consumption and the activation of IRS-1 (Ser307) in adipocytes induced by the activation of macrophages. Our findings imply that berberine improves insulin resistance by inhibiting M1 macrophage activation in adipose tissue. Copyright © 2016 Elsevier Inc. All rights reserved.

The Anti-Oxidant Ergothioneine Augments the Immunomodulatory Function of TLR Agonists by Direct Action on Macrophages

PubMed Central

Funami, Kenji; Takaki, Hiromi; Matsumoto, Misako; Kasahara, Masanori; Seya, Tsukasa

2017-01-01

L-Ergothioneine (EGT) is a naturally-occurring amino acid which is characterized by its antioxidant property; yet, the physiological role of EGT has yet to be established. We investigated the immune-enhancing properties of EGT, and found that it acts as a potentiator of toll-like receptor (TLR) signaling. When mouse bone marrow-derived macrophages (BMDMs) were pretreated with EGT, TLR signal-mediated cytokine production was augmented in BMDMs. The results were reproducible with TLR2, 3, 4 and 7 agonists. In particular, IL-6 and IL-12p40 were elevated further by pretreatment with EGT in BMDMs, suggesting the induction of M1 polarization. In co-culture assay with OT-II CD4+ T cells and splenic F4/80+ macrophages, EGT significantly induced Th17 skewing in CD4+ T cells. Thus, EGT is an immune modifier as well as a redox controller under TLR stimulation that induces M1 macrophages and a Th17 shift in inflammation. PMID:28114402

Imaging cellular pharmacokinetics of 18F-FDG and 6-NBDG uptake by inflammatory and stem cells.

PubMed

Zaman, Raiyan T; Tuerkcan, Silvan; Mahmoudi, Morteza; Saito, Toshinobu; Yang, Phillip C; Chin, Frederick T; McConnell, Michael V; Xing, Lei

2018-01-01

Myocardial infarction (MI) causes significant loss of cardiomyocytes, myocardial tissue damage, and impairment of myocardial function. The inability of cardiomyocytes to proliferate prevents the heart from self-regeneration. The treatment for advanced heart failure following an MI is heart transplantation despite the limited availability of the organs. Thus, stem-cell-based cardiac therapies could ultimately prevent heart failure by repairing injured myocardium that reverses cardiomyocyte loss. However, stem-cell-based therapies lack understanding of the mechanisms behind a successful therapy, including difficulty tracking stem cells to provide information on cell migration, proliferation and differentiation. In this study, we have investigated the interaction between different types of stem and inflammatory cells and cell-targeted imaging molecules, 18F-FDG and 6-NBDG, to identify uptake patterns and pharmacokinetics in vitro. Macrophages (both M1 and M2), human induced pluripotent stem cells (hiPSCs), and human amniotic mesenchymal stem cells (hAMSCs) were incubated with either 18F-FDG or 6-NBDG. Excess radiotracer and fluorescence were removed and a 100 μm-thin CdWO4 scintillator plate was placed on top of the cells for radioluminescence microscopy imaging of 18F-FDG uptake, while no scintillator was needed for fluorescence imaging of 6-NBDG uptake. Light produced following beta decay was imaged with a highly sensitive inverted microscope (LV200, Olympus) and an Electron Multiplying Charge-Couple Device (EM-CCD) camera. Custom-written software was developed in MATLAB for image processing. The average cellular activity of 18F-FDG in a single cell of hAMSCs (0.670±0.028 fCi/μm2, P = 0.001) was 20% and 36% higher compared to uptake in hiPSCs (0.540±0.026 fCi/μm2, P = 0.003) and macrophages (0.430±0.023 fCi/μm2, P = 0.002), respectively. hAMSCs exhibited the slowest influx (0.210 min-1) but the fastest efflux (0.327 min-1) rate compared to the other tested

Alternative activation of macrophages and pulmonary fibrosis are modulated by scavenger receptor, macrophage receptor with collagenous structure.

PubMed

Murthy, Shubha; Larson-Casey, Jennifer L; Ryan, Alan J; He, Chao; Kobzik, Lester; Carter, A Brent

2015-08-01

Alternative activation of alveolar macrophages is linked to fibrosis following exposure to asbestos. The scavenger receptor, macrophage receptor with collagenous structure (MARCO), provides innate immune defense against inhaled particles and pathogens; however, a receptor for asbestos has not been identified. We hypothesized that MARCO acts as an initial signaling receptor for asbestos, polarizes macrophages to a profibrotic M2 phenotype, and is required for the development of asbestos-induced fibrosis. Compared with normal subjects, alveolar macrophages isolated from patients with asbestosis express higher amounts of MARCO and have greater profibrotic polarization. Arginase 1 (40-fold) and IL-10 (265-fold) were higher in patients. In vivo, the genetic deletion of MARCO attenuated the profibrotic environment and pulmonary fibrosis in mice exposed to chrysotile. Moreover, alveolar macrophages from MARCO(-/-) mice polarize to an M1 phenotype, whereas wild-type mice have higher Ym1 (>3.0-fold) and nearly 7-fold more active TGF-β1 in bronchoalveolar lavage (BAL) fluid (BALF). Arg(432) and Arg(434) in domain V of MARCO are required for the polarization of macrophages to a profibrotic phenotype as mutation of these residues reduced FIZZ1 expression (17-fold) compared with cells expressing MARCO. These observations demonstrate that a macrophage membrane protein regulates the fibrotic response to lung injury and suggest a novel target for therapeutic intervention. © FASEB.

Supernatants from oral epithelial cells and gingival fibroblasts modulate human immunodeficiency virus type 1 promoter activation induced by periodontopathogens in monocytes/macrophages.

PubMed

González, O A; Ebersole, J L; Huang, C B

2010-04-01

Bacterial and host cell products during coinfections of Human Immunodeficiency Virus type 1-positive (HIV-1(+)) patients regulate HIV-1 recrudescence in latently infected cells (e.g. T cells, monocytes/macrophages), impacting highly active antiretroviral therapy (HAART) failure and progression of acquired immunodeficiency syndrome. A high frequency of oral opportunistic infections (e.g. periodontitis) in HIV-1(+) patients has been demonstrated; however, their potential to impact HIV-1 exacerbation is unclear. We sought to determine the ability of supernatants derived from oral epithelial cells (OKF4) and human gingival fibroblasts (Gin-4) challenged with periodontal pathogens, to modulate the HIV-1 promoter activation in monocytes/macrophages. BF24 monocytes/macrophages transfected with the HIV-1 promoter driving the expression of chloramphenicol acetyltransferase (CAT) were stimulated with Porphyromonas gingivalis, Fusobacterium nucleatum, or Treponema denticola in the presence of supernatants from OKF4 or Gin4 cells either unstimulated or previously pulsed with bacteria. CAT levels were determined by enzyme-linked immunosorbent assay and cytokine production was evaluated by Luminex beadlyte assays. OKF4 and Gin4 supernatants enhanced HIV-1 promoter activation particularly related to F. nucleatum challenge. An additive effect was observed in HIV-1 promoter activation when monocytes/macrophages were simultaneously stimulated with gingival cell supernatants and bacterial extracts. OKF4 cells produced higher levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukins -6 and -8 in response to F. nucleatum and P. gingivalis. Preincubation of OKF4 supernatants with anti-GM-CSF reduced the additive effect in periodontopathogen-induced HIV-1 promoter activation. These results suggest that soluble mediators produced by gingival resident cells in response to periodontopathogens could contribute to HIV-1 promoter activation in monocytes/macrophages

Immunological characterization of pulmonary intravascular macrophages

NASA Technical Reports Server (NTRS)

Chitko-McKown, C. G.; Reddy, D. N.; Chapes, S. K.; McKown, R. D.; Blecha, F.; Spooner, B. S. (Principal Investigator)

1992-01-01

Pulmonary intravascular macrophages (PIMs) are lung macrophages found apposed to the endothelium of pulmonary capillaries. In many species, they are responsible for the clearance of blood-borne particulates and pathogens; however, little else is known about their roles as immunologic effector cells. We compared PIMs with pulmonary alveolar macrophages (PAMs) to determine the relative immunological activities of these two cell populations. Our results suggested that both populations possess similar phagocytic and bactericidal activities. In assays measuring cytotoxicity, PIMs were more cytotoxic than PAMs against virally infected target cells; however, differences between these macrophage populations were not as marked when noninfected targets were used. LPS-stimulated PIMs produced more T-cell proliferative cytokines than PAMs, and both populations of nonstimulated macrophages produced similar amounts of the cytokines. In contrast, PAMs produced more TNF alpha and NO2- than PIMs when both populations were stimulated with LPS; however, nonstimulated PAMs and PIMs produced similar amounts of TNF alpha and NO2. These data suggest that bovine PIMs are immunologically active. Differences between the degrees of activity of PIMs and PAMs indicate that these macrophage populations may have different roles in lung surveillance.

Macrophage heterogeneity and cholesterol homeostasis: classically-activated macrophages are associated with reduced cholesterol accumulation following treatment with oxidized LDL.

PubMed

Chu, Eugene M; Tai, Daven C; Beer, Jennifer L; Hill, John S

2013-02-01

Macrophages are centrally involved during atherosclerosis development and are the predominant cell type that accumulates cholesterol in the plaque. Macrophages however, are heterogeneous in nature reflecting a variety of microenvironments and different phenotypes may be more prone to contribute towards atherosclerosis progression. Using primary human monocyte-derived macrophages, we sought to evaluate one aspect of atherogenic potential of different macrophage phenotypes by determining their propensity to associate with and accumulate oxidized low density lipoprotein (oxLDL). Classically-activated macrophages treated simultaneously with interferon γ (IFNγ) and tumor necrosis factor α (TNFα) associated with less oxLDL and accumulated less cholesterol compared to untreated controls. The combined treatment of IFNγ and TNFα reduced the mRNA expression of CD36 and the expression of both cell surface CD36 and macrophage scavenger receptor 1 (MSR1) protein. Under oxLDL loaded conditions, IFNγ and TNFα did not reduce macrophage protein expression of the transcription factor peroxisome proliferator-actived receptor γ (PPARγ) which is known to positively regulate CD36 expression. However, macrophages treated with IFNγ attenuated the ability of the PPARγ-specific agonist rosiglitazone from upregulating cell surface CD36 protein expression. Our results demonstrate that the observed reduction of cholesterol accumulation in macrophages treated with IFNγ and TNFα following oxLDL treatment was due at least in part to reduced cell surface CD36 and MSR1 protein expression. Copyright © 2012 Elsevier B.V. All rights reserved.

Modulating macrophage response to biomaterials

NASA Astrophysics Data System (ADS)

Zaveri, Toral

Macrophages recruited to the site of biomaterial implantation are the primary mediators of the chronic foreign body response to implanted materials. Since foreign body response limits performance and functional life of numerous implanted biomaterials/medical devices, various approaches have been investigated to modulate macrophage interactions with biomaterial surfaces to mitigate this response. In this work we have explored two independent approaches to modulate the macrophage inflammatory response to biomaterials. The first approach targets surface integrins, cell surface receptors that mediate cell adhesion to biomaterials through adhesive proteins spontaneously adsorbed on biomaterial surfaces. The second approach involves surface modification of biomaterials using nanotopographic features since nanotopography has been reported to modulate cell adhesion and viability in a cell type-dependent manner. More specifically, Zinc Oxide (ZnO) nanorod surface was investigated for its role in modulating macrophage adhesion and survival in vitro and foreign body response in vivo. For the first approach, we have investigated the role of integrin Mac-1 and RGD-binding integrins in the in-vivo osteolysis response and macrophage inflammatory processes of phagocytosis as well as inflammatory cytokine secretion in response to particulate biomaterials. We have also investigated the in vivo foreign body response (FBR) to subcutaneously implanted biomaterials by evaluating the thickness of fibrous capsule formed around the implants after 2 weeks of implantation. The role of Mac-1 integrin was isolated using a Mac-1 KO mouse and comparing it to a WT control. The role of RGD binding integrins in FBR was investigated by coating the implanted biomaterial with ELVAX(TM) polymer loaded with Echistatin which contains the RGD sequence. For the in-vivo osteolysis study and to study the in-vitro macrophage response to particulate biomaterials, we used the RGD peptide encapsulated in ELVAX

Ability of rabbit alveolar macrophages to dissolve metals.

PubMed

Lundborg, M; Lind, B; Camner, P

1984-01-01

Manganese dioxide particles, 0.1-0.5 micron, were added to samples of 2-3 X 10(6) rabbit alveolar macrophages. The amount of manganese added and dissolved from the particles, over periods of 0, 1, 3, and 5 days, was determined by flame atomic absorption spectrophotometry. Macrophages from six rabbits received about 10 micrograms of Mn, macrophages from two rabbits about 30 micrograms, and macrophages from another two rabbits about 100 micrograms. Over periods of 1, 3, and 5 days the macrophages in all three dose groups dissolved two to three times more Mn than was dissolved in control experiments. In control experiments solubility was studied in the medium without macrophages. Macrophages cultivated 3 days before the addition of MnO2 dissolved the particles within another 2 days to an extent similar to that in the control experiments. The ability of the macrophages to dissolve MnO2 particles might be related to the low pH values in the phagosomes. Studies of the ability of macrophages from various species to dissolve metal particles as well as of pH values in their phagosomes might lead to a better understanding of alveolar clearance of metal particles.

Differential S1P Receptor Profiles on M1- and M2-Polarized Macrophages Affect Macrophage Cytokine Production and Migration.

PubMed

Müller, Jan; von Bernstorff, Wolfram; Heidecke, Claus-Dieter; Schulze, Tobias

2017-01-01

Introduction . Macrophages are key players in complex biological processes. In response to environmental signals, macrophages undergo polarization towards a proinflammatory (M1) or anti-inflammatory (M2) phenotype. Sphingosine 1-phosphate (S1P) is a bioactive lysophospholipid that acts via 5 G-protein coupled receptors (S1P 1-5 ) in order to influence a broad spectrum of biological processes. This study assesses S1P receptor expression on macrophages before and after M1 and M2 polarization and performs a comparative analysis of S1P signalling in the two activational states of macrophages. Methods . Bone marrow derived macrophages (BMDM) from C57 BL/6 mice were cultured under either M1- or M2-polarizing conditions. S1P-receptor expression was determined by quantitative RT-PCR. Influence of S1P on macrophage activation, migration, phagocytosis, and cytokine secretion was assessed in vitro. Results . All 5 S1P receptor subclasses were expressed in macrophages. Culture under both M1- and M2-polarizing conditions led to significant downregulation of S1P 1 . In contrast, M1-polarized macrophages significantly downregulated S1P 4 . The expression of the remaining three S1P receptors did not change. S1P increased expression of iNOS under M2-polarizing conditions. Furthermore, S1P induced chemotaxis in M1 macrophages and changed cytokine production in M2 macrophages. Phagocytosis was not affected by S1P-signalling. Discussion . The expression of different specific S1P receptor profiles may provide a possibility to selectively influence M1- or M2-polarized macrophages.

Macrophage mitochondrial oxidative stress promotes atherosclerosis and nuclear factor-κB-mediated inflammation in macrophages.

PubMed

Wang, Ying; Wang, Gary Z; Rabinovitch, Peter S; Tabas, Ira

2014-01-31

Mitochondrial oxidative stress (mitoOS) has been shown to correlate with the progression of human atherosclerosis. However, definitive cell type-specific causation studies in vivo are lacking, and the molecular mechanisms of potential proatherogenic effects remain to be determined. Our aims were to assess the importance of macrophage mitoOS in atherogenesis and to explore the underlying molecular mechanisms. We first validated Western diet-fed Ldlr(-/-) mice as a model of human mitoOS-atherosclerosis association by showing that non-nuclear oxidative DNA damage, a marker of mitoOS in lesional macrophages, correlates with aortic root lesion development. To investigate the importance of macrophage mitoOS, we used a genetic engineering strategy in which the OS suppressor catalase was ectopically expressed in mitochondria (mCAT) in macrophages. MitoOS in lesional macrophages was successfully suppressed in these mice, and this led to a significant reduction in aortic root lesional area. The mCAT lesions had less monocyte-derived cells, less Ly6c(hi) monocyte infiltration into lesions, and lower levels of monocyte chemotactic protein-1. The decrease in lesional monocyte chemotactic protein-1 was associated with the suppression of other markers of inflammation and with decreased phosphorylation of RelA (NF-κB p65), indicating decreased activation of the proinflammatory NF-κB pathway. Using models of mitoOS in cultured macrophages, we showed that mCAT suppressed monocyte chemotactic protein-1 expression by decreasing the activation of the IκB-kinase β-RelA NF-κB pathway. MitoOS in lesional macrophages amplifies atherosclerotic lesion development by promoting NF-κB-mediated entry of monocytes and other inflammatory processes. In view of the mitoOS-atherosclerosis link in human atheromata, these findings reveal a potentially new therapeutic target to prevent the progression of atherosclerosis.

Suppressive effects of ketamine on macrophage functions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang Yi; Department of Anesthesiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan; Chen, T.-L.

2005-04-01

Ketamine is an intravenous anesthetic agent. Clinically, induction of anesthesia with ketamine can cause immunosuppression. Macrophages play important roles in host defense. In this study, we attempted to evaluate the effects of ketamine on macrophage functions and its possible mechanism using mouse macrophage-like Raw 264.7 cells as the experimental model. Exposure of macrophages to 10 and 100 {mu}M ketamine, which correspond to 0.1 and 1 times the clinically relevant concentration, for 1, 6, and 24 h had no effect on cell viability or lactate dehydrogenase release. When the administered concentration reached 1000 {mu}M, ketamine caused a release of lactate dehydrogenasemore » and cell death. Ketamine, at 10 and 100 {mu}M, did not affect the chemotactic activity of macrophages. Administration of 1000 {mu}M ketamine in macrophages resulted in a decrease in cell migration. Treatment of macrophages with ketamine reduced phagocytic activities. The oxidative ability of macrophages was suppressed by ketamine. Treatment with lipopolysaccharide induced TNF-{alpha}, IL-1{beta}, and IL-6 mRNA in macrophages. Administration of ketamine alone did not influence TNF-{alpha}, IL-1{beta}, or IL-6 mRNA production. Meanwhile, cotreatment with ketamine and lipopolysaccharide significantly inhibited lipopolysaccharide-induced TNF-{alpha}, IL-1{beta}, and IL-6 mRNA levels. Exposure to ketamine led to a decrease in the mitochondrial membrane potential. However, the activity of mitochondrial complex I NADH dehydrogenase was not affected by ketamine. This study shows that a clinically relevant concentration of ketamine (100 {mu}M) can suppress macrophage function of phagocytosis, its oxidative ability, and inflammatory cytokine production possibly via reduction of the mitochondrial membrane potential instead of direct cellular toxicity.« less

Risk factors for retained placenta.

PubMed

Coviello, Elizabeth M; Grantz, Katherine L; Huang, Chun-Chih; Kelly, Tara E; Landy, Helain J

2015-12-01

Retained placenta complicates 2-3% of vaginal deliveries and is a known cause of postpartum hemorrhage. Treatment includes manual or operative placental extraction, potentially increasing risks of hemorrhage, infections, and prolonged hospital stays. We sought to evaluate risk factors for retained placenta, defined as more than 30 minutes between the delivery of the fetus and placenta, in a large US obstetrical cohort. We included singleton, vaginal deliveries ≥24 weeks (n = 91,291) from the Consortium of Safe Labor from 12 US institutions (2002-2008). Multivariable logistic regression analyses estimated the adjusted odds ratios (OR) and 95% confidence intervals (CI) for potential risk factors for retained placenta stratified by parity, adjusting for relevant confounding factors. Characteristics such as stillbirth, maternal age, race, and admission body mass index were examined. Retained placenta complicated 1047 vaginal deliveries (1.12%). Regardless of parity, significant predictors of retained placenta included stillbirth (nulliparous adjusted OR, 5.67; 95% CI, 3.10-10.37; multiparous adjusted OR, 4.56; 95% CI, 2.08-9.94), maternal age ≥30 years, delivery at 24 0/7 to 27 6/7 compared with 34 weeks or later and delivery in a teaching hospital. In nulliparous women, additional risk factors were identified: longer first- or second-stage labor duration, whereas non-Hispanic black compared with non-Hispanic white race was found to be protective. Body mass index was not associated with an increased risk. Multiple risk factors for retained placenta were identified, particularly the strong association with stillbirth. It is plausible that there could be something intrinsic about stillbirth that causes a retained placenta, or perhaps there are shared pathways of certain etiologies of stillbirth and a risk of retained placenta. Copyright © 2015 Elsevier Inc. All rights reserved.

InhA1-Mediated Cleavage of the Metalloprotease NprA Allows Bacillus cereus to Escape From Macrophages.

PubMed

Haydar, Abbass; Tran, Seav-Ly; Guillemet, Elisabeth; Darrigo, Claire; Perchat, Stéphane; Lereclus, Didier; Coquet, Laurent; Jouenne, Thierry; Ramarao, Nalini

2018-01-01

Bacillus cereus is a Gram-positive spore-forming bacterium causing food poisoning and serious opportunistic infections. These infections are characterized by bacterial accumulation in the host despite the induction of inflammation. To circumvent inflammation, bacteria must resist the bactericidal activity of professional phagocytes, which constitute a first line of host defense against pathogens. Interactions between phagocytic cells and B. cereus are still poorly characterized and the mechanism of resistance to the host immune system is not known yet. We have previously shown that the spores are phagocytosed by macrophages but survive and escape from these cells. The metalloprotease InhA1 is a key effector involved in these processes. inhA1 -deficient spores are retained intracellularly, in contrast to the wild type strain spores. NprA is also a B. cereus metalloprotease able to cleave tissue components such as fibronectin, laminin, and collagen. Here, we show that NprA, concomitantly secreted with InhA1 in the B. cereus secretome, is essential to promote bacterial escape from macrophages. We show that InhA1 cleaves NprA at specific sites. This cleavage allows liberation of the mature form of the NprA protein in the supernatant of the wild type strain. This mature form of NprA is actually the principal effector allowing bacterial escape from host macrophages.

Molecular Mechanisms Modulating the Phenotype of Macrophages and Microglia

PubMed Central

Amici, Stephanie A.; Dong, Joycelyn; Guerau-de-Arellano, Mireia

2017-01-01

Macrophages and microglia play crucial roles during central nervous system development, homeostasis and acute events such as infection or injury. The diverse functions of tissue macrophages and microglia are mirrored by equally diverse phenotypes. A model of inflammatory/M1 versus a resolution phase/M2 macrophages has been widely used. However, the complexity of macrophage function can only be achieved by the existence of varied, plastic and tridimensional macrophage phenotypes. Understanding how tissue macrophages integrate environmental signals via molecular programs to define pathogen/injury inflammatory responses provides an opportunity to better understand the multilayered nature of macrophages, as well as target and modulate cellular programs to control excessive inflammation. This is particularly important in MS and other neuroinflammatory diseases, where chronic inflammatory macrophage and microglial responses may contribute to pathology. Here, we perform a comprehensive review of our current understanding of how molecular pathways modulate tissue macrophage phenotype, covering both classic pathways and the emerging role of microRNAs, receptor-tyrosine kinases and metabolism in macrophage phenotype. In addition, we discuss pathway parallels in microglia, novel markers helpful in the identification of peripheral macrophages versus microglia and markers linked to their phenotype. PMID:29176977

The macrophage marker translocator protein (TSPO) is down-regulated on pro-inflammatory ‘M1’ human macrophages

PubMed Central

Mandhair, Harpreet; Smyth, Erica; Dakin, Stephanie Georgina; Kiriakidis, Serafim; Wells, Lisa; Owen, David; Sabokbar, Afsie; Taylor, Peter

2017-01-01

The translocator protein (TSPO) is a mitochondrial membrane protein, of as yet uncertain function. Its purported high expression on activated macrophages, has lent utility to TSPO targeted molecular imaging in the form of positron emission tomography (PET), as a means to detect and quantify inflammation in vivo. However, existing literature regarding TSPO expression on human activated macrophages is lacking, mostly deriving from brain tissue studies, including studies of brain malignancy, and inflammatory diseases such as multiple sclerosis. Here, we utilized three human sources of monocyte derived macrophages (MDM), from THP-1 monocytes, healthy peripheral blood monocytes and synovial fluid monocytes from patients with rheumatoid arthritis, to undertake a detailed investigation of TSPO expression in activated macrophages. In this work, we demonstrate a consistent down-regulation of TSPO mRNA and protein in macrophages activated to a pro-inflammatory, or ‘M1’ phenotype. Conversely, stimulation of macrophages to an M2 phenotype with IL-4, dexamethasone or TGF-β1 did not alter TSPO expression, regardless of MDM source. The reasons for this are uncertain, but our study findings add some supporting evidence for recent investigations concluding that TSPO may be involved in negative regulation of inflammatory responses in macrophages. PMID:28968465

Effect of Enzymatic Digestion of Protein Derivatives Obtained from Mucuna pruriens L. on Production of Proinflammatory Mediators by BALB/c Mouse Macrophages.

PubMed

Martínez Leo, Edwin E; Arana Argáez, Victor E; Acevedo Fernández, Juan J; Puc, Rosa Moo; Segura Campos, Maira R

2018-04-25

Inflammation is considered to be a major risk factor for the pathogenesis of chronic non-communicable diseases. Macrophages are important immune cells, which regulate inflammation and host defense by secretion of proinflammatory mediators. Obtaining biopeptides by enzymatic hydrolysis adds value to proteins of vegetative origin, such as Mucuna pruriens L. The present study evaluated the effect of enzymatic digestion of protein derivatives obtained from M. pruriens L. on the production of proinflammatory mediators by BALB/c mouse macrophages. Five different molecular weight peptide fractions were obtained (F > 10, 5-10, 3-5, 1-3, and < 1 kDa, respectively). At 300 μg/mL, F5-10 kDa inhibited 50.26 and 61.00% NO and H 2 O 2 production, respectively. Moreover, F5-10 kDa reduced the IL-6 and TNFα levels to 60.25 and 69.54%, respectively. After enzymatic digestive simulation, F5-10 kDa decreased the inflammatory mediators.

Mammary stem cell and macrophage markers are enriched in normal tissue adjacent to inflammatory breast cancer.

PubMed

Reddy, Jay P; Atkinson, Rachel L; Larson, Richard; Burks, Jared K; Smith, Daniel; Debeb, Bisrat G; Ruffell, Brian; Creighton, Chad J; Bambhroliya, Arvind; Reuben, James M; Van Laere, Steven J; Krishnamurthy, Savitri; Symmans, William F; Brewster, Abenaa M; Woodward, Wendy A

2018-06-01

We hypothesized that breast tissue not involved by tumor in inflammatory breast cancer (IBC) patients contains intrinsic differences, including increased mammary stem cells and macrophage infiltration, which may promote the IBC phenotype. Normal breast parenchyma ≥ 5 cm away from primary tumors was obtained from mastectomy specimens. This included an initial cohort of 8 IBC patients and 60 non-IBC patients followed by a validation cohort of 19 IBC patients and 25 non-IBC patients. Samples were immunostained for either CD44 + CD49f + CD133/2 + mammary stem cell markers or the CD68 macrophage marker and correlated with IBC status. Quantitation of positive cells was determined using inForm software from PerkinElmer. We also examined the association between IBC status and previously published tumorigenic stem cell and IBC tumor signatures in the validation cohort samples. 8 of 8 IBC samples expressed isolated CD44 + CD49f + CD133/2 + stem cell marked cells in the initial cohort as opposed to 0/60 non-IBC samples (p = 0.001). Similarly, the median number of CD44 + CD49f + CD133/2 + cells was significantly higher in the IBC validation cohort as opposed to the non-IBC validation cohort (25.7 vs. 14.2, p = 0.007). 7 of 8 IBC samples expressed CD68 + histologically confirmed macrophages in initial cohort as opposed to 12/48 non-IBC samples (p = 0.001). In the validation cohort, the median number of CD68 + cells in IBC was 3.7 versus 1.0 in the non-IBC cohort (p = 0.06). IBC normal tissue was positively associated with a tumorigenic stem cell signature (p = 0.02) and with a 79-gene IBC signature (p < 0.001). Normal tissue from IBC patients is enriched for both mammary stem cells and macrophages and has higher association with both a tumorigenic stem cell signature and IBC-specific tumor signature. Collectively, these data suggest that IBC normal tissue differs from non-IBC tissue. Whether these changes occur before the tumor develops or

Effect of age on marrow macrophage number and function.

PubMed

Wang, C Q; Udupa, K B; Xiao, H; Lipschitz, D A

1995-10-01

Employing flow cytometry and a monoclonal antibody against the murine macrophage antigen, Mac-1, we found a significant increase in the number of marrow macrophages in aged mice. This was reflected as significant increase with age in the number of alpha-naphthyl acetate esterase positive cells, as well as in colony forming unit-macrophage (CFU-M) progenitor cells. Macrophages from the marrow of old mice generated significantly less tumor necrosis factor alpha (TNF alpha) than did macrophages from young mice, either spontaneously or when activated by granulocyte-macrophage colony stimulating factor (GM-CSF). Furthermore, conditioned medium (CM) derived from either marrow or peritoneal macrophages of old mice caused less suppression of burst forming unit-erythroid (BFU-E) colony growth than did CM obtained from young mice. Aging, therefore, is associated with an increase in the number of marrow macrophages that have an impaired ability to generate or release cytokines. The increase in macrophage number may reflect a compensation for their reduced function. Altered macrophage number and function may contribute to the age-related decline in hematopoietic reserve capacity.

Cement-retained versus screw-retained implant restorations: a critical review.

PubMed

Michalakis, Konstantinos X; Hirayama, Hiroshi; Garefis, Pavlos D

2003-01-01

This article presents a comparison of screw-retained and cement-retained implant prostheses based on the literature. The advantages, disadvantages, and limitations of the 2 different types of restorations are discussed, because it is important to understand the influence of the attachment mechanism on many clinical aspects of implant dentistry. Several factors essential to the long-term success of any implant prosthesis were reviewed with regard to both methods of fixation. These factors include: (1) ease of fabrication and cost, (2) passivity of the framework, (3) retention, (4) occlusion, (5) esthetics, (6) delivery, and (7) retrievability. (More than 50 references).

Src family kinase expression and subcellular localization in macrophages: implications for their role in CSF-1-induced macrophage migration.

PubMed

Dwyer, Amy R; Mouchemore, Kellie A; Steer, James H; Sunderland, Andrew J; Sampaio, Natalia G; Greenland, Eloise L; Joyce, David A; Pixley, Fiona J

2016-07-01

A major role of colony-stimulating factor-1 is to stimulate the differentiation of mononuclear phagocytic lineage cells into adherent, motile, mature macrophages. The colony-stimulating factor-1 receptor transduces colony-stimulating factor-1 signaling, and we have shown previously that phosphatidylinositol 3-kinase p110δ is a critical mediator of colony-stimulating factor-1-stimulated motility through the colony-stimulating factor-1 receptor pY721 motif. Src family kinases are also implicated in the regulation of macrophage motility and in colony-stimulating factor-1 receptor signaling, although functional redundancy of the multiple SFKs expressed in macrophages makes it challenging to delineate their specific functions. We report a comprehensive analysis of individual Src family kinase expression in macrophage cell lines and primary macrophages and demonstrate colony-stimulating factor-1-induced changes in Src family kinase subcellular localization, which provides clues to their distinct and redundant functions in macrophages. Moreover, expression of individual Src family kinases is both species specific and dependent on colony-stimulating factor-1-induced macrophage differentiation. Hck associated with the activated colony-stimulating factor-1 receptor, whereas Lyn associated with the receptor in a constitutive manner. Consistent with this, inhibitor studies revealed that Src family kinases were important for both colony-stimulating factor-1 receptor activation and colony-stimulating factor-1-induced macrophage spreading, motility, and invasion. Distinct colony-stimulating factor-1-induced changes in the subcellular localization of individual SFKs suggest specific roles for these Src family kinases in the macrophage response to colony-stimulating factor-1. © Society for Leukocyte Biology.

Loss of PPAR gamma in immune cells impairs the ability of abscisic acid to improve insulin sensitivity by suppressing monocyte chemoattractant protein-1 expression and macrophage infiltration into white adipose tissue.

PubMed

Guri, Amir J; Hontecillas, Raquel; Ferrer, Gerardo; Casagran, Oriol; Wankhade, Umesh; Noble, Alexis M; Eizirik, Decio L; Ortis, Fernanda; Cnop, Miriam; Liu, Dongmin; Si, Hongwei; Bassaganya-Riera, Josep

2008-04-01

Abscisic acid (ABA) is a natural phytohormone and peroxisome proliferator-activated receptor gamma (PPARgamma) agonist that significantly improves insulin sensitivity in db/db mice. Although it has become clear that obesity is associated with macrophage infiltration into white adipose tissue (WAT), the phenotype of adipose tissue macrophages (ATMs) and the mechanisms by which insulin-sensitizing compounds modulate their infiltration remain unknown. We used a loss-of-function approach to investigate whether ABA ameliorates insulin resistance through a mechanism dependent on immune cell PPARgamma. We characterized two phenotypically distinct ATM subsets in db/db mice based on their surface expression of F4/80. F4/80(hi) ATMs were more abundant and expressed greater concentrations of chemokine receptor (CCR) 2 and CCR5 when compared to F4/80(lo) ATMs. ABA significantly decreased CCR2(+) F4/80(hi) infiltration into WAT and suppressed monocyte chemoattractant protein-1 (MCP-1) expression in WAT and plasma. Furthermore, the deficiency of PPARgamma in immune cells, including macrophages, impaired the ability of ABA to suppress the infiltration of F4/80(hi) ATMs into WAT, to repress WAT MCP-1 expression and to improve glucose tolerance. We provide molecular evidence in vivo demonstrating that ABA improves insulin sensitivity and obesity-related inflammation by inhibiting MCP-1 expression and F4/80(hi) ATM infiltration through a PPARgamma-dependent mechanism.

Macrophages: An Inflammatory Link between Angiogenesis and Lymphangiogenesis

PubMed Central

Corliss, Bruce A.; Azimi, Mohammad S.; Munson, Jenny; Peirce, Shayn M.; Murfee, Walter Lee

2015-01-01

Angiogenesis and lymphangiogenesis often occur in response to tissue injury or in the presence of pathology (e.g. cancer), and it is these types of environments in which macrophages are activated and increased in number. Moreover, the blood vascular microcirculation and the lymphatic circulation serve as the conduits for entry and exit for monocyte-derived macrophages in nearly every tissue and organ. Macrophages both affect and are affected by the vessels through which they travel. Therefore, it is not surprising that examination of macrophage behaviors in both angiogenesis and lymphangiogenesis has yielded interesting observations that suggest macrophages may be key regulators of these complex growth and remodeling processes. In this review, we will take a closer look at macrophages through the lens of angiogenesis and lymphangiogenesis, examining how their dynamic behaviors may regulate vessel sprouting and function. We present macrophages as a cellular link that spatially and temporally connects angiogenesis with lymphangiogenesis, in both physiological growth and in pathological adaptations, such as tumorigenesis. As such, attempts to therapeutically target macrophages in order to affect these processes may be particularly effective, and studying macrophages in both settings will accelerate the field’s understanding of this important cell type in health and disease. PMID:26614117

The activation pattern of macrophages in giant cell (temporal) arteritis and primary angiitis of the central nervous system.

PubMed

Mihm, Bernhard; Bergmann, Markus; Brück, Wolfgang; Probst-Cousin, Stefan

2014-06-01

To determine if the pattern of macrophage activation reflects differences in the pathogenesis and clinical presentation of giant cell arteritis and primary angiitis of the central nervous system, specimens of 10 patients with giant cell arteritis and five with primary angiitis of the central nervous system were immunohistochemically studied and the expression of the macrophage activation markers 27E10, MRP14, MRP8 and 25F9 was determined in the vasculitic infiltrates. Thus, a partly different expression pattern of macrophage activation markers in giant cell arteritis and primary angiitis of the central nervous system was observed. The group comparison revealed that giant cell arteritis cases had significantly higher numbers of acute activated MRP14-positive macrophages, whereas primary angiitis of the central nervous system is characterized by a tendency toward more MRP8-positive intermediate/late activated macrophages. Furthermore, in giant cell arteritis comparably fewer CD8-positive lymphocytes were observed. These observations suggest, that despite their histopathological similarities, giant cell arteritis and primary angiitis of the central nervous system appear to represent either distinct entities within the spectrum of granulomatous vasculitides or different stages of similar disease processes. Their discrete clinical presentation is reflected by different activation patterns of macrophages, which may characterize giant cell arteritis as a more acute process and primary angiitis of the central nervous system as a more advanced inflammatory process. © 2013 Japanese Society of Neuropathology.

Origins of Brain Tumor Macrophages.

PubMed

De Palma, Michele

2016-12-12

The ontogeny of brain-tumor-associated macrophages is poorly understood. New findings indicate that both resident microglia and blood-derived monocytes generate the pool of macrophages that infiltrate brain tumors of either primary or metastatic origin. Copyright © 2016 Elsevier Inc. All rights reserved.

Conditional Macrophage Depletion Increases Inflammation and Does Not Inhibit the Development of Osteoarthritis in Obese Macrophage Fas-Induced Apoptosis-Transgenic Mice.

PubMed

Wu, Chia-Lung; McNeill, Jenna; Goon, Kelsey; Little, Dianne; Kimmerling, Kelly; Huebner, Janet; Kraus, Virginia; Guilak, Farshid

2017-09-01

To investigate whether short-term, systemic depletion of macrophages can mitigate osteoarthritis (OA) following injury in the setting of obesity. CSF-1R-GFP+ macrophage Fas-induced apoptosis (MaFIA)-transgenic mice that allow conditional depletion of macrophages were placed on a high-fat diet and underwent surgery to induce knee OA. A small molecule (AP20187) was administrated to deplete macrophages in MaFIA mice. The effects of macrophage depletion on acute joint inflammation, OA severity, and arthritic bone changes were evaluated using histology and micro-computed tomography. Immunohistochemical analysis was performed to identify various immune cells. The levels of serum and synovial fluid cytokines were also measured. Macrophage-depleted mice had significantly fewer M1 and M2 macrophages in the surgically operated joints relative to controls and exhibited decreased osteophyte formation immediately following depletion. Surprisingly, macrophage depletion did not attenuate the severity of OA in obese mice; instead, it induced systemic inflammation and led to a massive infiltration of CD3+ T cells and particularly neutrophils, but not B cells, into the injured joints. Macrophage-depleted mice also demonstrated a markedly increased number of proinflammatory cytokines including granulocyte colony-stimulating factor, interleukin-1β (IL-1β), IL-6, IL-8, and tumor necrosis factor in both serum and joint synovial fluid, although the mice showed a trend toward decreased levels of insulin and leptin in serum after macrophage depletion. Our findings indicate that macrophages are vital for modulating homeostasis of immune cells in the setting of obesity and suggest that more targeted approaches of depleting specific macrophage subtypes may be necessary to mitigate inflammation and OA in the setting of obesity. © 2017, American College of Rheumatology.

Mineralocorticoid Receptor Deficiency in Macrophages Inhibits Neointimal Hyperplasia and Suppresses Macrophage Inflammation Through SGK1-AP1/NF-κB Pathways.

PubMed

Sun, Jian-Yong; Li, Chao; Shen, Zhu-Xia; Zhang, Wu-Chang; Ai, Tang-Jun; Du, Lin-Juan; Zhang, Yu-Yao; Yao, Gao-Feng; Liu, Yan; Sun, Shuyang; Naray-Fejes-Toth, Aniko; Fejes-Toth, Geza; Peng, Yong; Chen, Mao; Liu, Xiaojing; Tao, Jun; Zhou, Bin; Yu, Ying; Guo, Feifan; Du, Jie; Duan, Sheng-Zhong

2016-05-01

Restenosis after percutaneous coronary intervention remains to be a serious medical problem. Although mineralocorticoid receptor (MR) has been implicated as a potential target for treating restenosis, the cellular and molecular mechanisms are largely unknown. This study aims to explore the functions of macrophage MR in neointimal hyperplasia and to delineate the molecular mechanisms. Myeloid MR knockout (MMRKO) mice and controls were subjected to femoral artery injury. MMRKO reduced intima area and intima/media ratio, Ki67- and BrdU-positive vascular smooth muscle cells, expression of proinflammatory molecules, and macrophage accumulation in injured arteries. MMRKO macrophages migrated less in culture. MMRKO decreased Ki67- and BrdU-positive macrophages in injured arteries. MMRKO macrophages were less Ki67-positive in culture. Conditioned media from MMRKO macrophages induced less migration, Ki67 positivity, and proinflammatory gene expression of vascular smooth muscle cells. After lipopolysaccharide treatment, MMRKO macrophages had decreased p-cFos and p-cJun compared with control macrophages, suggesting suppressed activation of activator protein-1 (AP1). Nuclear factor-κB (NF-κB) pathway was also inhibited by MMRKO, manifested by decreased p-IκB kinase-β and p-IκBα, increased IκBα expression, decreased nuclear translocation of p65 and p50, as welll as decreased phosphorylation and expression of p65. Finally, overexpression of serum-and-glucocorticoid-inducible-kinase-1 (SGK1) attenuated the effects of MR deficiency in macrophages. Selective deletion of MR in myeloid cells limits macrophage accumulation and vascular inflammation and, therefore, inhibits neointimal hyperplasia and vascular remodeling. Mechanistically, MR deficiency suppresses migration and proliferation of macrophages and leads to less vascular smooth muscle cell activation. At the molecular level, MR deficiency suppresses macrophage inflammatory response via SGK1-AP1/NF-κB pathways. �

Inhibition of macrophage activation and lipopolysaccaride-induced death by seco-steroids purified from Physalis angulata L.

PubMed

Soares, Milena B P; Bellintani, Moema C; Ribeiro, Ivone M; Tomassini, Therezinha C B; Ribeiro dos Santos, Ricardo

2003-01-10

Physalis angulata L. is an annual herb widely used in popular medicine for the treatment of a variety of pathologies. Here, we tested immunomodulatory activities of physalins, seco-steroids purified from P. angulata extracts. Addition of physalins B, F or G, but not D, caused a reduction in nitric oxide production by macrophages stimulated with lipopolysaccaride and interferon-gamma. In the presence of physalin B, macrophages stimulated with lipopolysaccaride, alone or in combination with interferon-gamma, produced lower levels of tumour necrosis factor (TNF)-alpha, interleukin-6 and interleukin-12. The inhibitory activity of physalin B, unlike that of dexamethasone, was not reversed by RU486 [(4-dimethylamino) phenyl-17beta-hydroxy-17-(1-propynyl)estra-4,9-dien-3-one], an antiglucocorticoid. Physalin B-treated mice had lower levels of serum TNF-alpha than control mice after lipopolysaccaride challenge. More importantly, mice injected with physalins B, F or G survived after a lethal lipopolysaccaride challenge. These results demonstrate that seco-steroids from P. angulata are potent immunomodulatory substances and act through a mechanism distinct from that of dexamethasone.

Plasminogen promotes macrophage phagocytosis in mice

PubMed Central

Ganapathy, Swetha; Settle, Megan; Plow, Edward F.

2014-01-01

The phagocytic function of macrophages plays a pivotal role in eliminating apoptotic cells and invading pathogens. Evidence implicating plasminogen (Plg), the zymogen of plasmin, in phagocytosis is extremely limited with the most recent in vitro study showing that plasmin acts on prey cells rather than on macrophages. Here, we use apoptotic thymocytes and immunoglobulin opsonized bodies to show that Plg exerts a profound effect on macrophage-mediated phagocytosis in vitro and in vivo. Plg enhanced the uptake of these prey by J774A.1 macrophage-like cells by 3.5- to fivefold Plg receptors and plasmin proteolytic activity were required for phagocytosis of both preys. Compared with Plg+/+ mice, Plg−/− mice exhibited a 60% delay in clearance of apoptotic thymocytes by spleen and an 85% reduction in uptake by peritoneal macrophages. Phagocytosis of antibody-mediated erythrocyte clearance by liver Kupffer cells was reduced by 90% in Plg−/− mice compared with Plg+/+ mice. A gene array of splenic and hepatic tissues from Plg−/− and Plg+/+ mice showed downregulation of numerous genes in Plg−/− mice involved in phagocytosis and regulation of phagocytic gene expression was confirmed in macrophage-like cells. Thus, Plg may play an important role in innate immunity by changing expression of genes that contribute to phagocytosis. PMID:24876560

S-nitrosothiol transport via PEPT2 mediates biological effects of nitric oxide gas exposure in macrophages.

PubMed

Brahmajothi, Mulugu V; Sun, Natalie Z; Auten, Richard L

2013-02-01

The pharmacological effects of nitric oxide (NO) administered as a gas are dependent on the conversion to S-nitrosocysteine, and as such are largely mediated by the L-type amino-acid transporters (LATs) in several cell types. The dipeptide transporter PEPT2 has been proposed as a second route for S-nitrosothiol (SNO) transport, but this has never been demonstrated. Because NO governs important immune functions in alveolar macrophages, we exposed rat alveolar macrophages (primary and NR8383 cells) to NO gas at the air-liquid interface ± LPS stimulation in the presence of PEPT2 substrate Cys-Gly (or the LAT substrate L-Cys) ± transporter competitors. We found that SNO uptake and NO-dependent actions, such as the activation of soluble guanylyl cyclase (sGC), the augmentation of sGC-dependent filamentous actin (F-actin) polymerization, phagocytosis, and the inhibition of NF-κB activation, were significantly augmented by the addition of Cys-Gly in a manner dependent on PEPT2 transport. We found parallel (and greater) effects that were dependent on LAT transport. The contribution of cystine/cysteine shuttling via system x cystine transporter (xCT) to SNO uptake was relatively minor. The observed effects were unaffected by NO synthase inhibition. The NO gas treatment of alveolar macrophages increased SNO uptake, the activation of sGC, F-actin polymerization, and phagocytosis, and inhibited NF-κB activation, in a manner dependent on SNO transport via PEPT2, as well as via LAT.

Macrophage Polarization in Chronic Inflammatory Diseases: Killers or Builders?

PubMed Central

Baci, Denisa; Tremolati, Marco; Fanuli, Matteo; Farronato, Giampietro; Mortara, Lorenzo

2018-01-01

Macrophages are key cellular components of the innate immunity, acting as the main player in the first-line defence against the pathogens and modulating homeostatic and inflammatory responses. Plasticity is a major feature of macrophages resulting in extreme heterogeneity both in normal and in pathological conditions. Macrophages are not homogenous, and they are generally categorized into two broad but distinct subsets as either classically activated (M1) or alternatively activated (M2). However, macrophages represent a continuum of highly plastic effector cells, resembling a spectrum of diverse phenotype states. Induction of specific macrophage functions is closely related to the surrounding environment that acts as a relevant orchestrator of macrophage functions. This phenomenon, termed polarization, results from cell/cell, cell/molecule interaction, governing macrophage functionality within the hosting tissues. Here, we summarized relevant cellular and molecular mechanisms driving macrophage polarization in “distant” pathological conditions, such as cancer, type 2 diabetes, atherosclerosis, and periodontitis that share macrophage-driven inflammation as a key feature, playing their dual role as killers (M1-like) and/or builders (M2-like). We also dissect the physio/pathological consequences related to macrophage polarization within selected chronic inflammatory diseases, placing polarized macrophages as a relevant hallmark, putative biomarkers, and possible target for prevention/therapy. PMID:29507865

Synthesis of Dipalmitoyl Lecithin by Alveolar Macrophages

PubMed Central

Mason, Robert J.; Huber, Gary; Vaughan, Martha

1972-01-01

A reliable, relatively simple method for isolation and quantification of disaturated lecithins is described. In rabbit lung, 34% of the lecithins were disaturated, in alveolar macrophages, 19%. More than 95% of the fatty acids of the disaturated lecithins from lung and alveolar macrophages was palmitic. Hence, the disaturated lecithins from these sources were essentially all dipalmitoyl lecithin. Both heterophils and alveolar macrophages incorporated 14C-labeled choline and palmitate into disaturated lecithins. Liver slices in which only about 1% of the lecithins were disaturated incorporated very little of these precursors into this fraction. Of the palmitate incorporated in vitro into disaturated lecithins by alveolar macrophages, heterophils, and lung slices, 37% was in the 1 position. In disaturated lecithins isolated from pulmonary lavage fluid, alveolar macrophages, and lung of rabbit 8-12 hr after a single intravenous injection of palmitic-1-14C acid, 45% of the 14C was in position 1. At earlier times, from 20-240 min after injection, the distribution of 14C was similar in the samples from lung, but in those from alveolar macrophages and lavage fluid, the percentage in position 1 was slightly lower. Glycerol-U-14C was incorporated into disaturated lecithins by alveolar macrophages and by lung slices in vitro. Both tissues incorporated very little label from ethanolamine or from methyl-labeled methionine into this fraction. All of the data are consistent with the view that alveolar macrophages synthesize dipalmitoyl lecithin via the cytidine diphosphate-choline pathway. PMID:5066597

Resveratrol Prevents Tumor Growth and Metastasis by Inhibiting Lymphangiogenesis and M2 Macrophage Activation and Differentiation in Tumor-associated Macrophages.

PubMed

Kimura, Yoshiyuki; Sumiyoshi, Maho

2016-01-01

Antitumor and antimetastatic effects of resveratrol on tumor-induced lymphangiogenesis through the regulation of M2 macrophages in tumor-associated macrophages currently remain unknown. Therefore, we herein examined the effects of resveratrol on M2 macrophage activation and differentiation, and those of resveratrol-treated condition medium (CM) in M2 macrophages on vascular endothelial cell growth factor (VEGF)-C-induced migration, invasion, and tube formation by human lymphatic endothelial cells (HLECs). Resveratrol (50 μM or 5-50 μM) inhibited the production of interleukin-10 and monocyte chemoattractant protein-1 in M2 macrophages, whereas it promoted that of transforming growth factor-β1. Resveratrol (25 and 50 μM) inhibited the phosphorylation of signal transducer and activator of transcript 3 without affecting its expression in the differentiation process of M2 macrophages. Furthermore, resveratrol-treated CM of M2 macrophages inhibited VEGF-C-induced HLEC migration, invasion, and lymphangiogenesis. Resveratrol (25 mg/kg, twice daily) inhibited tumor growth and metastasis to the lung and also reduced the area of lymphatic endothelial cells in tumors (in vivo). These results suggest that the antitumor and antimetastatic effects of resveratrol were partly due to antilymphangiogenesis through the regulation of M2 macrophage activation and differentiation.

Promising landscape for regulating macrophage polarization: epigenetic viewpoint

PubMed Central

Chen, Lu; Zhang, Wen; Xu, Zhenyu; Zuo, Jian; Jiang, Hui; Luan, Jiajie

2017-01-01

Macrophages are critical myeloid cells with the hallmark of phenotypic heterogeneity and functional plasticity. Macrophages phenotypes are commonly described as classically-activated M1 and alternatively-activated M2 macrophages which play an essential role in the tissues homeostasis and diseases pathogenesis. Alternations of macrophage polarization and function states require precise regulation of target-gene expression. Emerging data demonstrate that epigenetic mechanisms and transcriptional factors are becoming increasingly appreciated in the orchestration of macrophage polarization in response to local environmental signals. This review is to focus on the advanced concepts of epigenetics changes involved with the macrophage polarization, including microRNAs, DNA methylation and histone modification, which are responsible for the altered cellular signaling and signature genes expression during M1 or M2 polarization. Eventually, the persistent investigation and understanding of epigenetic mechanisms in tissue macrophage polarization and function will enhance the potential to develop novel therapeutic targets for various diseases. PMID:28915705

Direct imaging of macrophage activation during PDT treatment

NASA Astrophysics Data System (ADS)

Song, Sheng; Zhou, Feifan; Chen, Wei R.; Xing, Da

2012-03-01

Mounting evidence describes a more complex progress of macrophage activation during photodynamic therapy (PDT), which performing distinct immunological functions and different physiologies on surrounding cells and tissues. Macrophage-targeted PDT has been applied in the selective killing of cells involved in inflammation and tumor. We have previously shown that PDT-mediated tumor cells apoptosis can induce a higher level immune response than necrosis, and enhance the macrophage activation. However, the molecular mechanism of macrophage activation during PDT-induced apoptotic cells (AC) still unclear. Here, we use confocal microscopy to image the phagocytosis of tumor cells by macrophages. We also observed that PDT-treated AC can activate Toll-like receptors (TLRs) which are present on macrophages surface. Besides, the increase in nitric oxide (NO) formation in macrophages was detected in real time by a laser scanning microscopy. This study provided more details for understanding the molecular mechanism of the immune response induced by PDT-treated AC.

Vpx complementation of 'non-macrophage tropic' R5 viruses reveals robust entry of infectious HIV-1 cores into macrophages.

PubMed

Mlcochova, Petra; Watters, Sarah A; Towers, Greg J; Noursadeghi, Mahdad; Gupta, Ravindra K

2014-03-21

It is now known that clinically derived viruses are most commonly R5 tropic with very low infectivity in macrophages. As these viruses utilize CD4 inefficiently, defective entry has been assumed to be the dominant restriction. The implication is that macrophages are not an important reservoir for the majority of circulating viruses. Macrophage infection by clinical transmitted/founder isolates was 10-100 and 30-450 fold less efficient as compared to YU-2 and BaL respectively. Vpx complementation augmented macrophage infection by non-macrophage tropic viruses to the level of infectivity observed for YU-2 in the absence of Vpx. Augmentation was evident even when Vpx was provided 24 hours post-infection. The entry defect was measured as 2.5-5 fold, with a further 3.5-10 fold block at strong stop and subsequent stages of reverse transcription as compared to YU-2. The overall block to infection was critically dependent on the mechanism of entry as demonstrated by rescue of infection after pseudotyping with VSV-G envelope. Reverse transcription in macrophages could not be enhanced using a panel of cytokines or lipopolysaccharide (LPS). Although the predominant block to clinical transmitted/founder viruses is post-entry, infectivity is determined by Env-CD4 interactions and can be rescued with VSV-G pseudotyping. This suggests a functional link between the optimal entry pathway taken by macrophage tropic viruses and downstream events required for reverse transcription. Consistent with a predominantly post-entry block, replication of R5 using viruses can be greatly enhanced by Vpx. We conclude therefore that entry is not the limiting step and that macrophages represent clinically relevant reservoirs for 'non-macrophage tropic' viruses.

Specifically targeted delivery of protein to phagocytic macrophages

PubMed Central

Yu, Min; Chen, Zeming; Guo, Wenjun; Wang, Jin; Feng, Yupeng; Kong, Xiuqi; Hong, Zhangyong

2015-01-01

Macrophages play important roles in the pathogenesis of various diseases, and are important potential therapeutic targets. Furthermore, macrophages are key antigen-presenting cells and important in vaccine design. In this study, we report on the novel formulation (bovine serum albumin [BSA]-loaded glucan particles [GMP-BSA]) based on β-glucan particles from cell walls of baker’s yeast for the targeted delivery of protein to macrophages. Using this formulation, chitosan, tripolyphosphate, and alginate were used to fabricate colloidal particles with the model protein BSA via electrostatic interactions, which were caged and incorporated BSA very tightly within the β-glucan particle shells. The prepared GMP-BSA exhibited good protein-release behavior and avoided protein leakage. The particles were also highly specific to phagocytic macrophages, such as Raw 264.7 cells, primary bone marrow-derived macrophages, and peritoneal exudate macrophages, whereas the particles were not taken up by nonphagocytic cells, including NIH3T3, AD293, HeLa, and Caco-2. We hypothesize that these tightly encapsulated protein-loaded glucan particles deliver various types of proteins to macrophages with notably high selectivity, and may have broad applications in targeted drug delivery or vaccine design against macrophages. PMID:25784802

Inflammatory Macrophages Promotes Development of Diabetic Encephalopathy.

PubMed

Wang, Beiyun; Miao, Ya; Zhao, Zhe; Zhong, Yuan

2015-01-01

Diabetes and Alzheimer's disease are often associated with each other, whereas the relationship between two diseases is ill-defined. Although hyperglycemia during diabetes is a major cause of encephalopathy, diabetes may also cause chronic inflammatory complications including peripheral neuropathy. Hence the role and the characteristics of inflammatory macrophages in the development of diabetic encephalopathy need to be clarified. Diabetes were induced in mice by i.p. injection of streptozotocin (STZ). Two weeks after STZ injection and confirmation of development of diabetes, inflammatory macrophages were eliminated by i.p. injection of 20µg saporin-conjugated antibody against a macrophage surface marker CD11b (saporin-CD11b) twice per week, while a STZ-treated group received injection of rat IgG of same frequency as a control. The effects of macrophage depletion on brain degradation markers, brain malondialdehyde (MDA), catalase, superoxidase anion-positive cells and nitric oxide (NO) were measured. Saporin-CD11b significantly reduced inflammatory macrophages in brain, without affecting mouse blood glucose, serum insulin, glucose responses and beta cell mass. However, reduced brain macrophages significantly inhibited the STZ-induced decreases in brain MDA, catalase and superoxidase anion-positive cells, and the STZ-induced decreases in brain NO. Inflammatory macrophages may promote development of diabetic encephalopathy. © 2015 S. Karger AG, Basel.

Epigenomics of macrophages

PubMed Central

Gosselin, David; Glass, Christopher K

2014-01-01

Summary Macrophages play essential roles in tissue homeostasis, pathogen elimination, and tissue repair. A defining characteristic of these cells is their ability to efficiently adapt to a variety of abruptly changing and complex environments. This ability is intrinsically linked to a capacity to quickly alter their transcriptome, and this is tightly associated with the epigenomic organization of these cells and, in particular, their enhancer repertoire. Indeed, enhancers are genomic sites that serve as platforms for the integration of signaling pathways with the mechanisms that regulate mRNA transcription. Notably, transcription is pervasive at active enhancers and enhancer RNAs (eRNAs) are tightly coupled to regulated transcription of protein-coding genes. Furthermore, given that each cell type possesses a defining enhancer repertoire, studies on enhancers provide a powerful method to study how specialization of functions among the diverse macrophage subtypes may arise. Here, we review recent studies providing insights into the distinct mechanisms that contribute to the establishment of enhancers and their role in the regulation of transcription in macrophages. PMID:25319330

SIRT2 ameliorates lipopolysaccharide-induced inflammation in macrophages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Ae Sin; Jung, Yu Jin; Kim, Dal

2014-08-08

Highlights: • Knockout of SIRT2 attenuates lipopolysaccharide-induced iNOS expression. • Lipopolysaccharide-induced NO production is decreased in SIRT2 KO macrophage. • SIRT2 deficiency suppresses lipopolysaccharide-induced ROS production in macrophage. • M1-macrophage related factors are decreased in SIRT2 deficient cells. • SIRT2 deficiency decreases lipopolysaccharide-induced activation of NFκB. - Abstract: Introduction: SIRT2 is a NAD(+)-dependent deacetylases and associated with numerous processes such as infection, carcinogenesis, DNA damage and cell cycle regulation. However, the role of SIRT2 in inflammatory process in macrophage remains unclear. Materials and methods: In the present study, we have evaluated the regulatory effects of SIRT2 in lipopolysaccharide (LPS)-stimulated macrophagesmore » isolated from SIRT2 knockout (KO) and wild type (WT) mice or Raw264.7 macrophage cells. As inflammatory parameters, expression of inducible nitric oxide synthase (iNOS), the productions of nitric oxide, reactive oxygen species (ROS) and M1-macrophage-related factors were evaluated. We also examined the effects of SIRT2 on activation of nuclear factor-kappaB (NFκB) signaling. Results: SIRT2 deficiency inhibits LPS-induced iNOS mRNA and protein expression in bone marrow derived macrophages. SIRT2-siRNA transfection also suppressed LPS-induced iNOS expression in Raw264.7 macrophage cells. Bone marrow derived macrophages isolated from SIRT2 KO mice produced lower nitric oxide and expressed lower levels of M1-macrophage related markers including iNOS and CD86 in response to LPS than WT mice. Decrease of SIRT2 reduced the LPS-induced reactive oxygen species production. Deficiency of SIRT2 resulted in inhibition of NFκB activation through reducing the phosphorylation and degradation of IκBα. The phosphorylation and nuclear translocation of p65 was significantly decreased in SIRT2-deficient macrophages after LPS stimulation. Discussion: Our data suggested

30 CFR 57.20010 - Retaining dams.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Retaining dams. 57.20010 Section 57.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20010 Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be of...

30 CFR 56.20010 - Retaining dams.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Retaining dams. 56.20010 Section 56.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be of substantial...

30 CFR 57.20010 - Retaining dams.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Retaining dams. 57.20010 Section 57.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....20010 Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be of...

30 CFR 56.20010 - Retaining dams.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Retaining dams. 56.20010 Section 56.20010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Retaining dams. If failure of a water or silt retaining dam will create a hazard, it shall be of substantial...

Retaining African Americans in Higher Education: Challenging Paradigms for Retaining Students, Faculty and Administrators.

ERIC Educational Resources Information Center

Jones, Lee, Ed.

This collection discusses some of the issues surrounding the retention of African Americans in higher education, and it challenges traditional paradigms for retaining African American students, administrators, and faculty at predominantly White colleges. The chapters of part 1, "Retaining African-American Students," are: (1) "Creating an Affirming…

Transcription factor NFAT5 promotes macrophage survival in rheumatoid arthritis

PubMed Central

Choi, Susanna; Choi, Soo Youn; Kwon, H. Moo; Hwang, Daehee; Park, Yune-Jung; Cho, Chul-Soo

2017-01-01

Defective apoptotic death of activated macrophages has been implicated in the pathogenesis of rheumatoid arthritis (RA). However, the molecular signatures defining apoptotic resistance of RA macrophages are not fully understood. Here, global transcriptome profiling of RA macrophages revealed that the osmoprotective transcription factor nuclear factor of activated T cells 5 (NFAT5) critically regulates diverse pathologic processes in synovial macrophages including the cell cycle, apoptosis, and proliferation. Transcriptomic analysis of NFAT5-deficient macrophages revealed the molecular networks defining cell survival and proliferation. Proinflammatory M1-polarizing stimuli and hypoxic conditions were responsible for enhanced NFAT5 expression in RA macrophages. An in vitro functional study demonstrated that NFAT5-deficient macrophages were more susceptible to apoptotic death. Specifically, CCL2 secretion in an NFAT5-dependent fashion bestowed apoptotic resistance to RA macrophages in vitro. Injection of recombinant CCL2 into one of the affected joints of Nfat5+/– mice increased joint destruction and macrophage infiltration, demonstrating the essential role of the NFAT5/CCL2 axis in arthritis progression in vivo. Moreover, after intra-articular injection, NFAT5-deficient macrophages were more susceptible to apoptosis and less efficient at promoting joint destruction than were NFAT5-sufficient macrophages. Thus, NFAT5 regulates macrophage survival by inducing CCL2 secretion. Our results provide evidence that NFAT5 expression in macrophages enhances chronic arthritis by conferring apoptotic resistance to activated macrophages. PMID:28192374

Tie2 signaling cooperates with TNF to promote the pro-inflammatory activation of human macrophages independently of macrophage functional phenotype.

PubMed

García, Samuel; Krausz, Sarah; Ambarus, Carmen A; Fernández, Beatriz Malvar; Hartkamp, Linda M; van Es, Inge E; Hamann, Jörg; Baeten, Dominique L; Tak, Paul P; Reedquist, Kris A

2014-01-01

Angiopoietin (Ang) -1 and -2 and their receptor Tie2 play critical roles in regulating angiogenic processes during development, homeostasis, tumorigenesis, inflammation and tissue repair. Tie2 signaling is best characterized in endothelial cells, but a subset of human and murine circulating monocytes/macrophages essential to solid tumor formation express Tie2 and display immunosuppressive properties consistent with M2 macrophage polarization. However, we have recently shown that Tie2 is strongly activated in pro-inflammatory macrophages present in rheumatoid arthritis patient synovial tissue. Here we examined the relationship between Tie2 expression and function during human macrophage polarization. Tie2 expression was observed under all polarization conditions, but was highest in IFN-γ and IL-10 -differentiated macrophages. While TNF enhanced expression of a common restricted set of genes involved in angiogenesis and inflammation in GM-CSF, IFN-γ and IL-10 -differentiated macrophages, expression of multiple chemokines and cytokines, including CXCL3, CXCL5, CXCL8, IL6, and IL12B was further augmented in the presence of Ang-1 and Ang-2, via Tie2 activation of JAK/STAT signaling. Conditioned medium from macrophages stimulated with Ang-1 or Ang-2 in combination with TNF, sustained monocyte recruitment. Our findings suggest a general role for Tie2 in cooperatively promoting the inflammatory activation of macrophages, independently of polarization conditions.

Current Concept and Update of the Macrophage Plasticity Concept: Intracellular Mechanisms of Reprogramming and M3 Macrophage “Switch” Phenotype

PubMed Central

Malyshev, Igor; Malyshev, Yuri

2015-01-01

Macrophages play a key role in immunity. In this review, we consider the traditional notion of macrophage plasticity, data that do not fit into existing concepts, and a hypothesis for existence of a new switch macrophage phenotype. Depending on the microenvironment, macrophages can reprogram their phenotype toward the proinflammatory M1 phenotype or toward the anti-inflammatory M2 phenotype. Macrophage reprogramming involves well-coordinated changes in activities of signalling and posttranslational mechanisms. Macrophage reprogramming is provided by JNK-, PI3K/Akt-, Notch-, JAK/STAT-, TGF-β-, TLR/NF-κB-, and hypoxia-dependent pathways. Posttranscriptional regulation is based on micro-mRNA. We have hypothesized that, in addition to the M1 and M2 phenotypes, an M3 switch phenotype exists. This switch phenotype responds to proinflammatory stimuli with reprogramming towards the anti-inflammatory M2 phenotype or, contrarily, it responds to anti-inflammatory stimuli with reprogramming towards the proinflammatory M1 phenotype. We have found signs of such a switch phenotype in lung diseases. Understanding the mechanisms of macrophage reprogramming will assist in the selection of new therapeutic targets for correction of impaired immunity. PMID:26366410

M2 polarization enhances silica nanoparticle uptake by macrophages.

PubMed

Hoppstädter, Jessica; Seif, Michelle; Dembek, Anna; Cavelius, Christian; Huwer, Hanno; Kraegeloh, Annette; Kiemer, Alexandra K

2015-01-01

While silica nanoparticles have enabled numerous industrial and medical applications, their toxicological safety requires further evaluation. Macrophages are the major cell population responsible for nanoparticle clearance in vivo. The prevailing macrophage phenotype largely depends on the local immune status of the host. Whereas M1-polarized macrophages are considered as pro-inflammatory macrophages involved in host defense, M2 macrophages exhibit anti-inflammatory and wound-healing properties, but also promote tumor growth. We employed different models of M1 and M2 polarization: granulocyte-macrophage colony-stimulating factor/lipopolysaccharide (LPS)/interferon (IFN)-γ was used to generate primary human M1 cells and macrophage colony-stimulating factor (M-CSF)/interleukin (IL)-10 to differentiate M2 monocyte-derived macrophages (MDM). PMA-differentiated THP-1 cells were polarized towards an M1 type by LPS/IFN-γ and towards M2 by IL-10. Uptake of fluorescent silica nanoparticles (Ø26 and 41 nm) and microparticles (Ø1.75 μm) was quantified. At the concentration used (50 μg/ml), silica nanoparticles did not influence cell viability as assessed by MTT assay. Nanoparticle uptake was enhanced in M2-polarized primary human MDM compared with M1 cells, as shown by flow cytometric and microscopic approaches. In contrast, the uptake of microparticles did not differ between M1 and M2 phenotypes. M2 polarization was also associated with increased nanoparticle uptake in the macrophage-like THP-1 cell line. In accordance, in vivo polarized M2-like primary human tumor-associated macrophages obtained from lung tumors took up more nanoparticles than M1-like alveolar macrophages isolated from the surrounding lung tissue. In summary, our data indicate that the M2 polarization of macrophages promotes nanoparticle internalization. Therefore, the phenotypical differences between macrophage subsets should be taken into consideration in future investigations on nanosafety, but

M2 polarization enhances silica nanoparticle uptake by macrophages

PubMed Central

Hoppstädter, Jessica; Seif, Michelle; Dembek, Anna; Cavelius, Christian; Huwer, Hanno; Kraegeloh, Annette; Kiemer, Alexandra K.

2015-01-01

While silica nanoparticles have enabled numerous industrial and medical applications, their toxicological safety requires further evaluation. Macrophages are the major cell population responsible for nanoparticle clearance in vivo. The prevailing macrophage phenotype largely depends on the local immune status of the host. Whereas M1-polarized macrophages are considered as pro-inflammatory macrophages involved in host defense, M2 macrophages exhibit anti-inflammatory and wound-healing properties, but also promote tumor growth. We employed different models of M1 and M2 polarization: granulocyte-macrophage colony-stimulating factor/lipopolysaccharide (LPS)/interferon (IFN)-γ was used to generate primary human M1 cells and macrophage colony-stimulating factor (M-CSF)/interleukin (IL)-10 to differentiate M2 monocyte-derived macrophages (MDM). PMA-differentiated THP-1 cells were polarized towards an M1 type by LPS/IFN-γ and towards M2 by IL-10. Uptake of fluorescent silica nanoparticles (Ø26 and 41 nm) and microparticles (Ø1.75 μm) was quantified. At the concentration used (50 μg/ml), silica nanoparticles did not influence cell viability as assessed by MTT assay. Nanoparticle uptake was enhanced in M2-polarized primary human MDM compared with M1 cells, as shown by flow cytometric and microscopic approaches. In contrast, the uptake of microparticles did not differ between M1 and M2 phenotypes. M2 polarization was also associated with increased nanoparticle uptake in the macrophage-like THP-1 cell line. In accordance, in vivo polarized M2-like primary human tumor-associated macrophages obtained from lung tumors took up more nanoparticles than M1-like alveolar macrophages isolated from the surrounding lung tissue. In summary, our data indicate that the M2 polarization of macrophages promotes nanoparticle internalization. Therefore, the phenotypical differences between macrophage subsets should be taken into consideration in future investigations on nanosafety, but

Fusion between Intestinal epithelial cells and macrophages in a cancer context results in nuclear reprogramming.

PubMed

Powell, Anne E; Anderson, Eric C; Davies, Paige S; Silk, Alain D; Pelz, Carl; Impey, Soren; Wong, Melissa H

2011-02-15

The most deadly phase in cancer progression is attributed to the inappropriate acquisition of molecular machinery leading to metastatic transformation and spread of disease to distant organs. Although it is appreciated that metastasis involves epithelial-mesenchymal interplay, the underlying mechanism defining this process is poorly understood. Specifically, how cancer cells evade immune surveillance and gain the ability to navigate the circulatory system remains a focus. One possible mechanism underlying metastatic conversion is fusion between blood-derived immune cells and cancer cells. While this notion is a century old, in vivo evidence that cell fusion occurs within tumors and imparts genetic or physiologic changes remains controversial. We have previously demonstrated in vivo cell fusion between blood cells and intestinal epithelial cells in an injury setting. Here, we hypothesize that immune cells, such as macrophages, fuse with tumor cells imparting metastatic capabilities by transferring their cellular identity. We used parabiosis to introduce fluorescent-labeled bone marrow-derived cells to mice with intestinal tumors, finding that fusion between circulating blood-derived cells and tumor epithelium occurs during the natural course of tumorigenesis. Moreover, we identify the macrophage as a key cellular partner for this process. Interestingly, cell fusion hybrids retain a transcriptome identity characteristic of both parental derivatives, while also expressing a unique subset of transcripts. Our data supports the novel possibility that tumorigenic cell fusion may impart physical behavior attributed to migratory macrophages, including navigation of circulation and immune evasion. As such, cell fusion may represent a promising novel mechanism underlying the metastatic conversion of cancer cells. ©2011 AACR.

Inflammatory cytokines and hypoxia contribute to 18F-FDG uptake by cells involved in pannus formation in rheumatoid arthritis.

PubMed

Matsui, Tamiko; Nakata, Norihito; Nagai, Shigenori; Nakatani, Akira; Takahashi, Miwako; Momose, Toshimitsu; Ohtomo, Kuni; Koyasu, Shigeo

2009-06-01

Assessment of the activity of rheumatoid arthritis (RA) is important for the prediction of future articular destruction. (18)F-FDG PET is known to represent the metabolic activity of inflammatory disease, which correlates with the pannus volume measured by MRI or ultrasonography. To evaluate the correlation between (18)F-FDG accumulation and RA pathology, we assessed (18)F-FDG accumulation in vivo using collagen-induced arthritis (CIA) animal models and (3)H-FDG uptake in vitro using various cells involved in arthritis. (18)F-FDG PET images of rats with CIA were acquired on days 10, 14, and 17 after arthritis induction. The specimens were subsequently subjected to macroautoradiography, and the (18)F-FDG accumulation was compared with the histologic findings. (3)H-FDG uptake in vitro in inflammatory cells (neutrophils, macrophages, T cells, and fibroblasts) was measured to evaluate the contributions of these cells to (18)F-FDG accumulation. In addition, the influence on (3)H-FDG uptake of inflammatory factors, such as cytokines (tumor necrosis factor alpha [TNFalpha], interleukin 1 [IL-1], and IL-6), and hypoxia was examined. (18)F-FDG PET depicted swollen joints, and (18)F-FDG accumulation increased with the progression of arthritis. Histologically, a higher level of (18)F-FDG accumulation correlated with the pannus rather than the infiltration of inflammatory cells around the joints. In the in vitro (3)H-FDG uptake assay, fibroblasts showed the highest (3)H-FDG uptake, followed by neutrophils. Although only a small amount of (3)H-FDG was incorporated by resting macrophages, a dramatic increase in (3)H-FDG uptake in both fibroblasts and macrophages was observed when these cells were exposed to inflammatory cytokines, such as TNFalpha and IL-1, and hypoxia. Although neutrophils showed relatively high (3)H-FDG uptake without activation, no increase in (3)H-FDG uptake was observed in response to inflammatory cytokines. (3)H-FDG uptake by T cells was much lower than

The Dipeptidyl Peptidases 4, 8, and 9 in Mouse Monocytes and Macrophages: DPP8/9 Inhibition Attenuates M1 Macrophage Activation in Mice.

PubMed

Waumans, Yannick; Vliegen, Gwendolyn; Maes, Lynn; Rombouts, Miche; Declerck, Ken; Van Der Veken, Pieter; Vanden Berghe, Wim; De Meyer, Guido R Y; Schrijvers, Dorien; De Meester, Ingrid

2016-02-01

Atherosclerosis remains the leading cause of death in Western countries. Dipeptidyl peptidase (DPP) 4 has emerged as a novel target for the prevention and treatment of atherosclerosis. Family members DPP8 and 9 are abundantly present in macrophage-rich regions of atherosclerotic plaques, and DPP9 inhibition attenuates activation of human M1 macrophages in vitro. Studying this family in a mouse model for atherosclerosis would greatly advance our knowledge regarding their potential as therapeutic targets. We found that DPP4 is downregulated during mouse monocyte-to-macrophage differentiation. DPP8 and 9 expression seems relatively low in mouse monocytes and macrophages. Viability of primary mouse macrophages is unaffected by DPP4 or DPP8/9 inhibition. Importantly, DPP8/9 inhibition attenuates macrophage activation as IL-6 secretion is significantly decreased. Mouse macrophages respond similarly to DPP inhibition, compared to human macrophages. This shows that the mouse could become a valid model species for the study of DPPs as therapeutic targets in atherosclerosis.

Biochemistry of proinflammatory macrophage activation.

PubMed

Nonnenmacher, Yannic; Hiller, Karsten

2018-06-01

In the last decade, metabolism has been recognized as a major determinant of immunological processes. During an inflammatory response, macrophages undergo striking changes in their metabolism. This metabolic reprogramming is governed by a complex interplay between metabolic enzymes and metabolites of different pathways and represents the basis for proper macrophage function. It is now evident that these changes go far beyond the well-known Warburg effect and the perturbation of metabolic targets is being investigated as a means to treat infections and auto-immune diseases. In the present review, we will aim to provide an overview of the metabolic responses during proinflammatory macrophage activation and show how these changes modulate the immune response.

Macrophage Solubilization and Cytotoxicity of Indium-Containing Particles as in vitro Correlates to Pulmonary Toxicity in vivo

PubMed Central

Gwinn, William M.; Qu, Wei; Bousquet, Ronald W.; Price, Herman; Shines, Cassandra J.; Taylor, Genie J.; Waalkes, Michael P.; Morgan, Daniel L.

2015-01-01

Macrophage-solubilized indium-containing particles (ICPs) were previously shown in vitro to be cytotoxic. In this study, we compared macrophage solubilization and cytotoxicity of indium phosphide (InP) and indium-tin oxide (ITO) with similar particle diameters (∼1.5 µm) and then determined if relative differences in these in vitro parameters correlated with pulmonary toxicity in vivo. RAW 264.7 macrophages were treated with InP or ITO particles and cytotoxicity was assayed at 24 h. Ionic indium was measured in 24 h culture supernatants. Macrophage cytotoxicity and particle solubilization in vitro were much greater for InP compared with ITO. To correlate changes in vivo, B6C3F1 mice were treated with InP or ITO by oropharyngeal aspiration. On Days 14 and 28, bronchoalveolar lavage (BAL) and pleural lavage (PL) fluids were collected and assayed for total leukocytes. Cell differentials, lactate dehydrogenase activity, and protein levels were also measured in BAL. All lavage parameters were greatly increased in mice treated with InP compared with ITO. These data suggest that macrophage solubilization and cytotoxicity of some ICPs in vitro are capable of predicting pulmonary toxicity in vivo. In addition, these differences in toxicity were observed despite the two particulate compounds containing similar amounts of indium suggesting that solubilization, not total indium content, better reflects the toxic potential of some ICPs. Soluble InCl3 was shown to be more cytotoxic than InP to macrophages and lung epithelial cells in vitro further suggesting that ionic indium is the primary cytotoxic component of InP. PMID:25527823

Influenza virus replication in macrophages: balancing protection and pathogenesis

PubMed Central

Beck, Donald; Bianchini, Elizabeth

2017-01-01

Macrophages are essential for protection against influenza A virus infection, but are also implicated in the morbidity and mortality associated with severe influenza disease, particularly during infection with highly pathogenic avian influenza (HPAI) H5N1 virus. While influenza virus infection of macrophages was once thought to be abortive, it is now clear that certain virus strains can replicate productively in macrophages. This may have important consequences for the antiviral functions of macrophages, the course of disease and the outcome of infection for the host. In this article, we review findings related to influenza virus replication in macrophages and the impact of productive replication on macrophage antiviral functions. A clear understanding of the interactions between influenza viruses and macrophages may lead to new antiviral therapies to relieve the burden of severe disease associated with influenza viruses. PMID:28884667

Alveolar macrophages develop from fetal monocytes that differentiate into long-lived cells in the first week of life via GM-CSF

PubMed Central

De Kleer, Ismé; Henri, Sandrine; Post, Sijranke; Vanhoutte, Leen; De Prijck, Sofie; Deswarte, Kim; Malissen, Bernard; Hammad, Hamida; Lambrecht, Bart N.

2013-01-01

Tissue-resident macrophages can develop from circulating adult monocytes or from primitive yolk sac–derived macrophages. The precise ontogeny of alveolar macrophages (AMFs) is unknown. By performing BrdU labeling and parabiosis experiments in adult mice, we found that circulating monocytes contributed minimally to the steady-state AMF pool. Mature AMFs were undetectable before birth and only fully colonized the alveolar space by 3 d after birth. Before birth, F4/80hiCD11blo primitive macrophages and Ly6ChiCD11bhi fetal monocytes sequentially colonized the developing lung around E12.5 and E16.5, respectively. The first signs of AMF differentiation appeared around the saccular stage of lung development (E18.5). Adoptive transfer identified fetal monocytes, and not primitive macrophages, as the main precursors of AMFs. Fetal monocytes transferred to the lung of neonatal mice acquired an AMF phenotype via defined developmental stages over the course of one week, and persisted for at least three months. Early AMF commitment from fetal monocytes was absent in GM-CSF–deficient mice, whereas short-term perinatal intrapulmonary GM-CSF therapy rescued AMF development for weeks, although the resulting AMFs displayed an immature phenotype. This demonstrates that tissue-resident macrophages can also develop from fetal monocytes that adopt a stable phenotype shortly after birth in response to instructive cytokines, and then self-maintain throughout life. PMID:24043763

Protective Role of Ternatin Anthocyanins and Quercetin Glycosides from Butterfly Pea (Clitoria ternatea Leguminosae) Blue Flower Petals against Lipopolysaccharide (LPS)-Induced Inflammation in Macrophage Cells.

PubMed

Nair, Vimal; Bang, Woo Young; Schreckinger, Elisa; Andarwulan, Nuri; Cisneros-Zevallos, Luis

2015-07-22

Twelve phenolic metabolites (nine ternatin anthocyanins and three glycosylated quercetins) were identified from the blue flowers of Clitoria ternatea by high-performance liquid chromatography diode array detection and electrospray ionization/mass spectrometry (HPLC-DAD-ESI/MS(n)). Three anthocyanins not reported in this species before show fragmentation pattern of the ternatin class. Extracts were fractionated in fractions containing flavonols (F3) and ternatin anthocyanins (F4). In general, C. ternatea polyphenols showed anti-inflammatory properties in lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells with distinct molecular targets. Flavonols (F3) showed strong inhibition of COX-2 activity and partial ROS suppression. On the other hand, the ternatin anthocyanins (F4) inhibited nuclear NF-κB translocation, iNOS protein expression, and NO production through a non-ROS suppression mechanism. Accordingly, quercetin glycosides and ternatin anthocyanins from the blue flower petals of C. ternatea may be useful in developing drugs or nutraceuticals for protection against chronic inflammatory diseases by suppressing the excessive production of pro-inflammatory mediators from macrophage cells.

The glycosylation and characterization of the candidate Gc macrophage activating factor.

PubMed

Ravnsborg, Tina; Olsen, Dorthe T; Thysen, Anna Hammerich; Christiansen, Maja; Houen, Gunnar; Højrup, Peter

2010-04-01

The vitamin D binding protein, Gc globulin, has in recent years received some attention for its role as precursor for the extremely potent macrophage activating factor (GcMAF). An O-linked trisaccharide has been allocated to the threonine residue at position 420 in two of the three most common isoforms of Gc globulin (Gc1s and Gc1f). A substitution for a lysine residue at position 420 in Gc2 prevents this isoform from being glycosylated at that position. It has been suggested that Gc globulin subjected sequentially to sialidase and galactosidase treatment generates GcMAF in the form of Gc globulin with only a single GalNAc attached to T420. In this study we confirm the location of a linear trisaccharide on T420. Furthermore, we provide the first structural evidence of the generation of the proposed GcMAF by use of glycosidase treatment and mass spectrometry. Additionally the generated GcMAF candidate was tested for its effect on cytokine release from macrophages in human whole blood. Copyright 2010 Elsevier B.V. All rights reserved.

Alternative activation modifies macrophage resistance to Mycobacterium bovis.

PubMed

Castillo-Velázquez, Uziel; Aranday-Cortés, Elihú; Gutiérrez-Pabello, José A

2011-07-05

The aim of this study was to evaluate the influence of macrophage alternative activation in the intracellular pathogen natural disease resistance phenotype of the host. Macrophage monolayers from resistant (R) (3) or susceptible (S) (3) cattle donors were treated with 10 ng/ml of bovine recombinant IL-4 (rbIL-4), and infected with virulent and avirulent Mycobacterium bovis (MOI 10:1). Bactericidal assays were performed to assess the bacterial phagocytic index and intracellular survival. Total RNA was reverse transcribed and used to analyze the relative changes in gene expression of IL-10, IL-12, IL-18 IL-1β, TNF-α, MCP-1, MCP-2, IL-6, MIP-1, MIP-3, iNOS, ARGII and SLAM by real time PCR. Cell supernatants were collected and nitric oxide and arginase production was assessed. Apoptosis induction was measured by TUNEL. IL-4 treatment increased the phagocytic index in both R and S macrophages; however intracellular survival was augmented mainly in S macrophages. Alternative activation decreased gene expression of pro-inflammatory cytokines, nitric oxide production and DNA fragmentation mainly in R macrophages. On the other hand, arginase production was not different between R and S macrophages. Alternative activation modifies the macrophage response against M. bovis. IL-4 treatment minimized the functional differences that exist between R and S macrophages. Copyright © 2011. Published by Elsevier B.V.

Macrophage-specific nanotechnology-driven CD163 overexpression in human macrophages results in an M2 phenotype under inflammatory conditions.

PubMed

Alvarado-Vazquez, Perla Abigail; Bernal, Laura; Paige, Candler A; Grosick, Rachel L; Moracho Vilrriales, Carolina; Ferreira, David Wilson; Ulecia-Morón, Cristina; Romero-Sandoval, E Alfonso

2017-08-01

M1 macrophages release proinflammatory factors during inflammation. They transit to an M2 phenotype and release anti-inflammatory factors to resolve inflammation. An imbalance in the transition from M1 to M2 phenotype in macrophages contributes to the development of persistent inflammation. CD163, a member of the scavenger receptor cysteine-rich family, is an M2 macrophage marker. The functional role of CD163 during the resolution of inflammation is not completely known. We postulate that CD163 contributes to the transition from M1 to M2 phenotype in macrophages. We induced CD163 gene in THP-1 and primary human macrophages using polyethylenimine nanoparticles grafted with a mannose ligand (Man-PEI). This nanoparticle specifically targets cells of monocytic origin via mannose receptors. Cells were challenged with a single or a double stimulation of lipopolysaccharide (LPS). A CD163 or empty plasmid was complexed with Man-PEI nanoparticles for cell transfections. Quantitative RT-PCR, immunocytochemistry, and ELISAs were used for molecular assessments. CD163-overexpressing macrophages displayed reduced levels of tumor necrosis factor-alpha (TNF)-α and monocytes chemoattractant protein (MCP)-1 after a single stimulation with LPS. Following a double stimulation paradigm, CD163-overexpressing macrophages showed an increase of interleukin (IL)-10 and IL-1ra and a reduction of MCP-1. This anti-inflammatory phenotype was partially blocked by an anti-CD163 antibody (effects on IL-10 and IL-1ra). A decrease in the release of TNF-α, IL-1β, and IL-6 was observed in CD163-overexpressing human primary macrophages. The release of IL-6 was blocked by an anti-CD163 antibody in the CD163-overexpressing group. Our data show that the induction of the CD163 gene in human macrophages under inflammatory conditions produces changes in cytokine secretion in favor of an anti-inflammatory phenotype. Targeting macrophages to induce CD163 using cell-directed nanotechnology is an attractive

Heparanase regulates the M1 polarization of renal macrophages and their crosstalk with renal epithelial tubular cells after ischemia/reperfusion injury.

PubMed

Masola, Valentina; Zaza, Gianluigi; Bellin, Gloria; Dall'Olmo, Luigi; Granata, Simona; Vischini, Gisella; Secchi, Maria Francesca; Lupo, Antonio; Gambaro, Giovanni; Onisto, Maurizio

2018-02-01

Heparanase (HPSE) is part of the biologic network triggered by ischemia/reperfusion (I/R) injury, a complication of renal transplantation and acute kidney injury. During this period, the kidney or graft undergoes a process of macrophages recruitment and activation. HPSE may therefore control these biologic effects. We measured the ability of HPSE and its inhibitor, SST0001, to regulate macrophage polarization and the crosstalk between macrophages and HK-2 renal tubular cells during in vitro hypoxia/reoxygenation (H/R). Furthermore, we evaluated in vivo renal inflammation, macrophage polarization, and histologic changes in mice subjected to monolateral I/R and treated with SST0001 for 2 or 7 d. The in vitro experiments showed that HPSE sustained M1 macrophage polarization and modulated apoptosis, the release of damage associated molecular patterns in post-H/R tubular cells, the synthesis of proinflammatory cytokines, and the up-regulation of TLRs on both epithelial cells and macrophages. HPSE also regulated M1 polarization induced by H/R-injured tubular cells and the partial epithelial-mesenchymal transition of these epithelial cells by M1 macrophages. All these effects were prevented by inhibiting HPSE. Furthermore, the inhibition of HPSE in vivo reduced inflammation and M1 polarization in mice undergoing I/R injury, partially restored renal function and normal histology, and reduced apoptosis. These results show for the first time that HPSE regulates macrophage polarization as well as renal damage and repair after I/R. HPSE inhibitors could therefore provide a new pharmacologic approach to minimize acute kidney injury and to prevent the chronic profibrotic damages induced by I/R.-Masola, V., Zaza, G., Bellin, G., Dall'Olmo, L., Granata, S., Vischini, G., Secchi, M. F., Lupo, A., Gambaro, G., Onisto, M. Heparanase regulates the M1 polarization of renal macrophages and their crosstalk with renal epithelial tubular cells after ischemia/reperfusion injury.

Characteristics of adipose tissue macrophages and macrophage-derived insulin-like growth factor-1 in virus-induced obesity.

PubMed

Park, S; Park, H-L; Lee, S-Y; Nam, J-H

2016-03-01

Various pathogens are implicated in the induction of obesity. Previous studies have confirmed that human adenovirus 36 (Ad36) is associated with increased adiposity, improved glycemic control and induction of inflammation. The Ad36-induced inflammation is reflected in the infiltration of macrophages into adipose tissue. However, the characteristics and role of adipose tissue macrophages (ATMs) and macrophage-secreted factors in virus-induced obesity (VIO) are unclear. Although insulin-like growth factor-1 (IGF-1) is involved in obesity metabolism, the contribution of IGF secreted by macrophages in VIO has not been studied. Four-week-old male mice were studied 1 week and 12 weeks after Ad36 infection for determining the characteristics of ATMs in VIO and diet-induced obesity (DIO). In addition, macrophage-specific IGF-1-deficient (MIKO) mice were used to study the involvement of IGF-1 in VIO. In the early stage of VIO (1 week after Ad36 infection), the M1 ATM sub-population increased, which increased the M1/M2 ratio, whereas DIO did not cause this change. In the late stage of VIO (12 weeks after Ad36 infection), the M1/M2 ratio did not change because the M1 and M2 ATM sub-populations increased to a similar extent, despite an increase in adiposity. By contrast, DIO increased the M1/M2 ratio. In addition, VIO in wild-type mice upregulated angiogenesis in adipose tissue and improved glycemic control. However, MIKO mice showed no increase in adiposity, angiogenesis, infiltration of macrophages into adipose tissue, or improvement in glycemic control after Ad36 infection. These data suggest that IGF-1 secreted by macrophages may contribute to hyperplasia and hypertrophy in adipose tissue by increasing angiogenesis, which helps to maintain the 'adipose tissue robustness'.

Macrophages: Contributors to Allograft Dysfunction, Repair or Innocent Bystanders?

PubMed Central

Mannon, Roslyn B.

2012-01-01

Purpose of this review Macrophages are members of the innate immune response. However, their role in the adaptive immune response is not known. The purpose of this review is to highlight our current understanding of macrophage structure and function and how they may participate in allograft injury. Recent Findings Studies in acute kidney injury models identify macrophages as key mediators of inflammatory injury while more recent studies indicate that they may play a reparative role, depending on phenotype—M1 or M2 type macrophages. Mregs, generated in vitro, appear to have immune suppressive abilities and a unique phenotype. In solid organ transplant, the emphasis of studies has been on acute or chronic injury. These data are derived from animal models using depletion of macrophages or antagonizing their activation and inflammatory responses. The relative contribution of macrophage phenotype in transplantation has not been explored. Summary These studies suggest that macrophages play an injurious role in acute cellular allograft rejection, as well as in chronic injury. Infiltration of an allograft with macrophages is also associated with worse graft function and poor prognosis. Further studies are needed to understand the mechanisms of macrophage mediated injury, explore their potential reparative role and determine if they or their functional products are biomarkers of poor graft outcomes. PMID:22157320

Macrophages: contributors to allograft dysfunction, repair, or innocent bystanders?

PubMed

Mannon, Roslyn B

2012-02-01

Macrophages are members of the innate immune response. However, their role in the adaptive immune response is not known. The purpose of this review is to highlight our current understanding of macrophage structure and function and how they may participate in allograft injury. Studies in acute kidney injury models identify macrophages as key mediators of inflammatory injury, while more recent studies indicate that they may play a reparative role, depending on phenotype - M1 or M2 type macrophages. Mregs, generated in vitro, appear to have immune suppressive abilities and a unique phenotype. In solid-organ transplant, the emphasis of studies has been on acute or chronic injury. These data are derived from animal models using depletion of macrophages or antagonizing their activation and inflammatory responses. The relative contribution of macrophage phenotype in transplantation has not been explored. These studies suggest that macrophages play an injurious role in acute cellular allograft rejection, as well as in chronic injury. Infiltration of an allograft with macrophages is also associated with worse graft function and poor prognosis. Further studies are needed to understand the mechanisms of macrophage-mediated injury, explore their potential reparative role, and determine if they or their functional products are biomarkers of poor graft outcomes.

Nanopatterned bulk metallic glass-based biomaterials modulate macrophage polarization.

PubMed

Shayan, Mahdis; Padmanabhan, Jagannath; Morris, Aaron H; Cheung, Bettina; Smith, Ryan; Schroers, Jan; Kyriakides, Themis R

2018-06-01

Polarization of macrophages by chemical, topographical and mechanical cues presents a robust strategy for designing immunomodulatory biomaterials. Here, we studied the ability of nanopatterned bulk metallic glasses (BMGs), a new class of metallic biomaterials, to modulate murine macrophage polarization. Cytokine/chemokine analysis of IL-4 or IFNγ/LPS-stimulated macrophages showed that the secretion of TNF-α, IL-1α, IL-12, CCL-2 and CXCL1 was significantly reduced after 24-hour culture on BMGs with 55 nm nanorod arrays (BMG-55). Additionally, under these conditions, macrophages increased phagocytic potential and exhibited decreased cell area with multiple actin protrusions. These in vitro findings suggest that nanopatterning can modulate biochemical cues such as IFNγ/LPS. In vivo evaluation of the subcutaneous host response at 2 weeks demonstrated that the ratio of Arg-1 to iNOS increased in macrophages adjacent to BMG-55 implants, suggesting modulation of polarization. In addition, macrophage fusion and fibrous capsule thickness decreased and the number and size of blood vessels increased, which is consistent with changes in macrophage responses. Our study demonstrates that nanopatterning of BMG implants is a promising technique to selectively polarize macrophages to modulate the immune response, and also presents an effective tool to study mechanisms of macrophage polarization and function. Implanted biomaterials elicit a complex series of tissue and cellular responses, termed the foreign body response (FBR), that can be influenced by the polarization state of macrophages. Surface topography can influence polarization, which is broadly characterized as either inflammatory or repair-like. The latter has been linked to improved outcomes of the FBR. However, the impact of topography on macrophage polarization is not fully understood, in part, due to a lack of high moduli biomaterials that can be reproducibly processed at the nanoscale. Here, we studied

TNF signaling and macrophages govern fin regeneration in zebrafish larvae.

PubMed

Nguyen-Chi, Mai; Laplace-Builhé, Béryl; Travnickova, Jana; Luz-Crawford, Patricia; Tejedor, Gautier; Lutfalla, Georges; Kissa, Karima; Jorgensen, Christian; Djouad, Farida

2017-08-10

Macrophages are essential for appendage regeneration after amputation in regenerative species. The molecular mechanisms through which macrophages orchestrate blastema formation and regeneration are still unclear. Here, we use the genetically tractable and transparent zebrafish larvae to study the functions of polarized macrophage subsets during caudal fin regeneration. After caudal fin amputation, we show an early and transient accumulation of pro-inflammatory macrophages concomitant with the accumulation of non-inflammatory macrophages which, in contrast to pro-inflammatory macrophages, remain associated to the fin until the end of the regeneration. Chemical and genetic depletion of macrophages suggested that early recruited macrophages that express TNFα are critical for blastema formation. Combining parabiosis and morpholino knockdown strategies, we show that TNFα/TNFR1 signaling pathway is required for the fin regeneration. Our study reveals that TNFR1 has a necessary and direct role in blastema cell activation suggesting that macrophage subset balance provides the accurate TNFα signal to prime regeneration in zebrafish.

Studies on the mechanisms of macrophage activation. I. Destruction of intracellular Leishmania enriettii in macrophages activated by cocultivation with stimulated lymphocytes.

PubMed

Mauel, J; Buchmüller, Y; Behin, R

1978-08-01

When cultures of normal mouse peritoneal macrophages were infected with the intracellular protozoan parasite Leishmania enrietti, the micro-organism was found to survive intracellularly for several days, apparently without multiplication. However, exposure of infected macrophages to certain stimuli led to rapid parasite killing and digestion, providing a sensitive assay with which the mechanisms of macrophage activation can be studied. Microbicidal activity was induced by incubation of macrophages with syngeneic spleen lymphocytes, which were stimulated either by allogeneic cells in mixed lymphocyte culture (MLC) or by the plant lectin concanavalin A (Con A). Cocultivation with MLCs led to parasite killing within 48-72 h, whereas exposure of infected cells to Con A-stimulated lymphocytes resulted in substantial destruction of the micro-organism within less than 24 h, an effect which was dependent on the presence of thymus-derived lymphocytes and was inhibited by alpha methyl-mannoside. Incubation with Con A-stimulated lymphocytes also led to lysis of part of the macrophage monolayer. However, parasite killing did not result from decreased macrophage survival, as destruction of the micro-organism was highest under culture conditions which were the least detrimental to the phagocytes. Conversely, excess numbers of Con A-stimulated lymphocytes were less efficient at inducing macrophage activation and displayed marked toxicity to the macrophage monolayer. When spleen cells were stimulated by Con A at concentrations above 10 mug/ml, a decrease was noted in the capacity of macrophages to destroy the parasite, probably reflecting a toxicity of the lectin for lymphocytes resulting in impaired activating capacity.

Secretory products of macrophages: twenty-five years on.

PubMed

Nathan, Carl

2012-04-01

No longer do scientists look down on macrophages as "garbage men" that act "nonspecifically." Last fall's Nobel Prizes honored two of the few scientists who studied macrophages three decades ago. Now perhaps thousands do, and the subtypes they describe reflect ongoing discoveries of macrophages' extraordinary plasticity.

Apoptosis inhibitor of macrophage (AIM) expression in alveolar macrophages in COPD

PubMed Central

2013-01-01

Background Marked accumulation of alveolar macrophages (AM) conferred by apoptosis resistance has been implicated in pathogenesis of chronic obstructive pulmonary disease (COPD). Apoptosis inhibitor of macrophage (AIM), has been shown to be produced by mature tissue macrophages and AIM demonstrates anti-apoptotic property against multiple apoptosis-inducing stimuli. Accordingly, we attempt to determine if AIM is expressed in AM and whether AIM is involved in the regulation of apoptosis in the setting of cigarette smoke extract (CSE) exposure. Methods Immunohistochemical evaluations of AIM were performed. Immunostaining was assessed by counting total and positively staining AM numbers in each case (n = 5 in control, n = 5 in non-COPD smoker, n = 5 in COPD). AM were isolated from bronchoalveolar lavage fluid (BALF). The changes of AIM expression levels in response to CSE exposure in AM were evaluated. Knock-down of anti-apoptotic Bcl-xL was mediated by siRNA transfection. U937 monocyte-macrophage cell line was used to explore the anti-apoptotic properties of AIM. Results The numbers of AM and AIM-positive AM were significantly increased in COPD lungs. AIM expression was demonstrated at both mRNA and protein levels in isolated AM, which was enhanced in response to CSE exposure. AIM significantly increased Bcl-xL expression levels in AM and Bcl-xL was involved in a part of anti-apoptotic mechanisms of AIM in U937 cells in the setting of CSE exposure. Conclusions These results suggest that AIM expression in association with cigarette smoking may be involved in accumulation of AM in COPD. PMID:23497247

Mycobacterium tuberculosis promotes genomic instability in macrophages

PubMed Central

Castro-Garza, Jorge; Luévano-Martínez, Miriam Lorena; Villarreal-Treviño, Licet; Gosálvez, Jaime; Fernández, José Luis; Dávila-Rodríguez, Martha Imelda; García-Vielma, Catalina; González-Hernández, Silvia; Cortés-Gutiérrez, Elva Irene

2018-01-01

BACKGROUND Mycobacterium tuberculosis is an intracellular pathogen, which may either block cellular defensive mechanisms and survive inside the host cell or induce cell death. Several studies are still exploring the mechanisms involved in these processes. OBJECTIVES To evaluate the genomic instability of M. tuberculosis-infected macrophages and compare it with that of uninfected macrophages. METHODS We analysed the possible variations in the genomic instability of Mycobacterium-infected macrophages using the DNA breakage detection fluorescence in situ hybridisation (DBD-FISH) technique with a whole human genome DNA probe. FINDINGS Quantitative image analyses showed a significant increase in DNA damage in infected macrophages as compared with uninfected cells. DNA breaks were localised in nuclear membrane blebs, as confirmed with DNA fragmentation assay. Furthermore, a significant increase in micronuclei and nuclear abnormalities were observed in infected macrophages versus uninfected cells. MAIN CONCLUSIONS Genomic instability occurs during mycobacterial infection and these data may be seminal for future research on host cell DNA damage in M. tuberculosis infection. PMID:29412354

Mycobacterium tuberculosis promotes genomic instability in macrophages.

PubMed

Castro-Garza, Jorge; Luévano-Martínez, Miriam Lorena; Villarreal-Treviño, Licet; Gosálvez, Jaime; Fernández, José Luis; Dávila-Rodríguez, Martha Imelda; García-Vielma, Catalina; González-Hernández, Silvia; Cortés-Gutiérrez, Elva Irene

2018-03-01

Mycobacterium tuberculosis is an intracellular pathogen, which may either block cellular defensive mechanisms and survive inside the host cell or induce cell death. Several studies are still exploring the mechanisms involved in these processes. To evaluate the genomic instability of M. tuberculosis-infected macrophages and compare it with that of uninfected macrophages. We analysed the possible variations in the genomic instability of Mycobacterium-infected macrophages using the DNA breakage detection fluorescence in situ hybridisation (DBD-FISH) technique with a whole human genome DNA probe. Quantitative image analyses showed a significant increase in DNA damage in infected macrophages as compared with uninfected cells. DNA breaks were localised in nuclear membrane blebs, as confirmed with DNA fragmentation assay. Furthermore, a significant increase in micronuclei and nuclear abnormalities were observed in infected macrophages versus uninfected cells. Genomic instability occurs during mycobacterial infection and these data may be seminal for future research on host cell DNA damage in M. tuberculosis infection.

Human macrophage ATP7A is localized in the trans-Golgi apparatus, controls intracellular copper levels, and mediates macrophage responses to dermal wounds.

PubMed

Kim, Ha Won; Chan, Qilin; Afton, Scott E; Caruso, Joseph A; Lai, Barry; Weintraub, Neal L; Qin, Zhenyu

2012-02-01

The copper transporter ATP7A has attracted significant attention since the discovery of its gene mutation leading to human Menkes disease. We previously reported that ATP7A is highly expressed in the human vasculature and identified a novel vascular function of ATP7A in modulation of the expression and activity of extracellular superoxide dismutase. We recently identified that ATP7A expression in THP-1 cells (a monocyte/macrophage model cell line) plays a role in the oxidation of low density lipoproteins, indicating that it is necessary to further investigate its expression and function in monocytes/macrophages. In the current study, we demonstrated the protein and mRNA expression of ATP7A in human peripheral blood mononuclear cell (PBMC)-derived macrophages and alveolar macrophages. ATP7A was strongly co-localized with the trans-Golgi apparatus in PBMC-derived macrophages. Intracellular copper, detected by synchrotron X-ray fluorescence microscopy, was found to be distributed to the nucleus and cytoplasm in human THP-1 cells. To confirm the role of endogenous ATP7A in macrophage copper homeostasis, we performed inductively coupled plasma mass spectrometry in murine peritoneal macrophages, which showed markedly increased intracellular copper levels in macrophages isolated from ATP7A-deficient mice versus control mice. Moreover, the role of ATP7A in regulating macrophage responses to dermal wounds was studied by introduction of control and ATP7A-downregulated THP-1 cells into dermal wounds of nude mice. Infiltration of THP-1 cells into the wounded area (detected by expression of human macrophage markers MAC2 and CD68) was reduced in response to downregulation of ATP7A, hinting decreased macrophage accumulation subsequent to dermal wounds. In summary, alongside our previous studies, these findings indicate that human macrophage ATP7A is localized in the trans-Golgi apparatus, regulates intracellular copper levels, and mediates macrophage responses to a dermal wound.

Dakin Solution Alters Macrophage Viability and Function

DTIC Science & Technology

2014-07-18

A, Guerrero JM, Calvo JR. Comparative effects of two endodontic irrigants, chlorhexidine digluconate and sodium hypochlorite , on macrophage adhesion...July 2014 Available online 18 July 2014 Keywords: Sodium hypochlorite Dakin solution Macrophages Phagocytosis a b s t r a c t Background: Macrophages are...important in wound defense and healing. Dakin’s solution (DS), buffered sodium hypochlorite , has been used since World War I as a topical antimi

Role of macrophage colony-stimulating factor (M-CSF)-dependent macrophages in gastric ulcer healing in mice.

PubMed

Kawahara, Y; Nakase, Y; Isomoto, Y; Matsuda, N; Amagase, K; Kato, S; Takeuchi, K

2011-08-01

We examined the role of macrophage colony-stimulating factor (M-CSF)-dependent macrophages in the healing of gastric ulcers in mice. Male M-CSF-deficient (op/op) and M-CSF-expressing heterozygote (+/?) mice were used. Gastric ulcers were induced by thermal cauterization under ether anesthesia, and healing was observed for 14 days after ulceration. The numbers of macrophages and microvessels in the gastric mucosa were determined immunohistochemically with anti-CD68 and anti-CD31 antibodies, respectively. Expression of tumor necrosis factor (TNF)-α, cyclooxygenase (COX)-2, and vascular endothelial growth factor (VEGF) mRNA was determined via real-time reverse transcription-polymerase chain reaction (RT-PCR), and the mucosal content of prostaglandin (PG) E(2) was determined via enzyme immunoassay on day 10 after ulceration. The healing of gastric ulcers was significantly delayed in op/op mice compared with +/? mice. Further, significantly fewer macrophages were observed in the normal gastric mucosa of op/op mice than in +/? mice. Ulcer induction caused a marked accumulation of macrophages around the ulcer base in +/? mice, but this response was attenuated in op/op mice. The mucosal PGE(2) content as well as the expression of COX-2, VEGF, and TNF-α mRNA were all upregulated in the ulcerated area of +/? mice but significantly suppressed in op/op mice. The degree of vascularization in the ulcerated area was significantly lower in op/op mice than in +/? mice. Taken together, these results suggest that M-CSF-dependent macrophages play an important role in the healing of gastric ulcers, and that this action may be associated with angiogenesis promoted by upregulation of COX-2/PGE(2) production.

CXCL4 induces a unique transcriptome in monocyte-derived macrophages

PubMed Central

Gleissner, Christian A.; Shaked, Iftach; Little, Kristina M.; Ley, Klaus

2012-01-01

In atherosclerotic arteries, blood monocytes differentiate to macrophages in the presence of growth factors like macrophage colony-stimulation factor (MCSF) and chemokines like platelet factor 4 (CXCL4). To compare the gene expression signature of CXCL4-induced macrophages with MCSF-induced macrophages or macrophages polarized with IFN-γ/LPS (M1) or IL-4 (M2), we cultured primary human peripheral blood monocytes for six days. mRNA expression was measured by Affymetrix gene chips and differences were analyzed by Local Pooled Error test, Profile of Complex Functionality and Gene Set Enrichment Analysis. 375 genes were differentially expressed between MCSF- and CXCL4-induced macrophages, 206 of them overexpressed in CXCL4 macrophages coding for genes implicated in the inflammatory/immune response, antigen processing/presentation, and lipid metabolism. CXCL4-induced macrophages overexpressed some M1 and M2 genes and the corresponding cytokines at the protein level, however, their transcriptome clustered with neither M1 nor M2 transcriptomes. They almost completely lost the ability to phagocytose zymosan beads. Genes linked to atherosclerosis were not consistently up- or downregulated. Scavenger receptors showed lower and cholesterol efflux transporters higher expression in CXCL4- than MCSF-induced macrophages, resulting in lower LDL content. We conclude that CXCL4 induces a unique macrophage transcriptome distinct from known macrophage types, defining a new macrophage differentiation that we propose to call M4. PMID:20335529

Tissue-specific contribution of macrophages to wound healing.

PubMed

Minutti, Carlos M; Knipper, Johanna A; Allen, Judith E; Zaiss, Dietmar M W

2017-01-01

Macrophages are present in all tissues, either as resident cells or monocyte-derived cells that infiltrate into tissues. The tissue site largely determines the phenotype of tissue-resident cells, which help to maintain tissue homeostasis and act as sentinels of injury. Both tissue resident and recruited macrophages make a substantial contribution to wound healing following injury. In this review, we evaluate how macrophages in two fundamentally distinct tissues, i.e. the lung and the skin, differentially contribute to the process of wound healing. We highlight the commonalities of macrophage functions during repair and contrast them with distinct, tissue-specific functions that macrophages fulfill during the different stages of wound healing. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Alternatively activated macrophages in helminth infections

PubMed Central

Kreider, Timothy; Anthony, Robert M.; Urban, Joseph F.; Gause, William C.

2007-01-01

Summary Helminthic parasites can trigger highly polarized immune responses typically associated with increased numbers of CD4+ Th2 cells, eosinophils, mast cells, and basophils. These cell populations are thought to coordinate an effective response ultimately leading to parasite expulsion, but they also play a role in the regulation of associated pathologic inflammation. Recent studies suggest that macrophages, conventionally associated with IFNγ-dominant Th1-type responses to many bacteria and viruses, also play an essential role in the Th2-type inflammatory response. These macrophages are referred to as alternatively activated macrophages (AAMΦs) as they express a characteristic pattern of cell surface and secreted molecules distinct from that of classically activated macrophages (CAMΦs) associated with microbe infections. In this review, we will discuss recent findings regarding the role of AAMΦs in the development of disease and host protection following helminth infection. PMID:17702561

A prenylated flavonoid, 10-oxomornigrol F, exhibits anti-inflammatory effects by activating the Nrf2/heme oxygenase-1 pathway in macrophage cells.

PubMed

Tran, Phi-Long; Tran, Phuong Thao; Tran, Huynh Nguyen Khanh; Lee, Suhyun; Kim, Okwha; Min, Buyng-Sun; Lee, Jeong-Hyung

2018-02-01

Prenylated flavonoids are a unique class of naturally occurring flavonoids that have various pharmacological activities. In the present study, we investigated the anti-inflammatory effect in murine macrophages of a prenylated flavonoid, 10-oxomornigrol F (OMF), which was isolated from the twigs of Morus alba (Moraceae). OMF inhibited the lipopolysaccharide (LPS)-induced production of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 in RAW264.7 cells, as well as in mouse bone marrow-derived macrophages (BMMs). OMF also rescued LPS-induced septic mortality in ICR mice. LPS-induced expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α and IL-6 was also significantly suppressed by OMF treatment in RAW264.7 cells. Treatment of RAW264.7 cells with OMF induced heme oxygenase (HO)-1 mRNA and protein expression and increased the nuclear translocation of the nuclear factor-E2-related factor 2 (Nrf2) as well as the expression of Nrf2 target genes, such as NAD(P)H:quinone oxidoreductase 1 (NQO1). Treatment of RAW264.7 cells with OMF increased the intracellular level of reactive oxygen species (ROS) and the phosphorylation levels of p38 mitogen-activated protein kinase (MAPK); co-treatment with the antioxidant N-acetyl-cysteine (NAC) blocked this OMF-induced p38 MAPK phosphorylation. Moreover, NAC, or SB203580 (a p38 MAPK inhibitor), blocked the OMF-induced nuclear translocation of Nrf2 and HO-1 expression, suggesting that OMF induces HO-1 expression by activating Nrf2 through the p38 MAPK pathway. Consistent with the notion that the Nrf2/HO-1 pathway has anti-inflammatory properties, inhibiting HO-1 significantly abrogated the anti-inflammatory effects of OMF in LPS-stimulated RAW264.7 cells. Taken together, these findings suggest that OMF exerts its anti-inflammatory effect by activating the Nrf2/HO-1 pathway, and may be a potential Nrf2 activator to prevent or treat inflammatory diseases. Copyright © 2017

Protein Thiol Redox Signaling in Monocytes and Macrophages.

PubMed

Short, John D; Downs, Kevin; Tavakoli, Sina; Asmis, Reto

2016-11-20

Monocyte and macrophage dysfunction plays a critical role in a wide range of inflammatory disease processes, including obesity, impaired wound healing diabetic complications, and atherosclerosis. Emerging evidence suggests that the earliest events in monocyte or macrophage dysregulation include elevated reactive oxygen species production, thiol modifications, and disruption of redox-sensitive signaling pathways. This review focuses on the current state of research in thiol redox signaling in monocytes and macrophages, including (i) the molecular mechanisms by which reversible protein-S-glutathionylation occurs, (ii) the identification of bona fide S-glutathionylated proteins that occur under physiological conditions, and (iii) how disruptions of thiol redox signaling affect monocyte and macrophage functions and contribute to atherosclerosis. Recent Advances: Recent advances in redox biochemistry and biology as well as redox proteomic techniques have led to the identification of many new thiol redox-regulated proteins and pathways. In addition, major advances have been made in expanding the list of S-glutathionylated proteins and assessing the role that protein-S-glutathionylation and S-glutathionylation-regulating enzymes play in monocyte and macrophage functions, including monocyte transmigration, macrophage polarization, foam cell formation, and macrophage cell death. Protein-S-glutathionylation/deglutathionylation in monocytes and macrophages has emerged as a new and important signaling paradigm, which provides a molecular basis for the well-established relationship between metabolic disorders, oxidative stress, and cardiovascular diseases. The identification of specific S-glutathionylated proteins as well as the mechanisms that control this post-translational protein modification in monocytes and macrophages will facilitate the development of new preventive and therapeutic strategies to combat atherosclerosis and other metabolic diseases. Antioxid. Redox Signal

Regulation of macrophage development and function in peripheral tissues

PubMed Central

Lavin, Yonit; Mortha, Arthur; Rahman, Adeeb; Merad, Miriam

2015-01-01

Macrophages are immune cells of haematopoietic origin that provide crucial innate immune defence and have tissue-specific functions in the regulation and maintenance of organ homeostasis. Recent studies of macrophage ontogeny, as well as transcriptional and epigenetic identity, have started to reveal the decisive role of the tissue stroma in the regulation of macrophage function. These findings suggest that most macrophages seed the tissues during embryonic development and functionally specialize in response to cytokines and metabolites that are released by the stroma and drive the expression of unique transcription factors. In this Review, we discuss how recent insights into macrophage ontogeny and macrophage–stroma interactions contribute to our understanding of the crosstalk that shapes macrophage function and the maintenance of organ integrity. PMID:26603899

miRNA let-7b modulates macrophage polarization and enhances tumor-associated macrophages to promote angiogenesis and mobility in prostate cancer.

PubMed

Wang, Zhigang; Xu, Lu; Hu, Yinying; Huang, Yanqin; Zhang, Yujuan; Zheng, Xiufen; Wang, Shanshan; Wang, Yifan; Yu, Yanrong; Zhang, Meng; Yuan, Keng; Min, Weiping

2016-05-09

Macrophage polarization is a highly plastic physiological process that responds to a variety of environmental factors by changing macrophage phenotype and function. Tumor-associated macrophages (TAMs) are generally recognized as promoting tumor progression. As universal regulators, microRNAs (miRNAs) are functionally involved in numerous critical cellular processes including macrophage polarization. Let-7b, a miRNA, has differential expression patterns in inflamed tissues compared with healthy controls. However, whether and how miRNA let-7b regulates macrophage phenotype and function is unclear. In this report, we find that up-regulation of let-7b is characteristic of prostatic TAMs, and down-regulation of let-7b in TAMs leads to changes in expression profiles of inflammatory cytokines, such as IL-12, IL-23, IL-10 and TNF-α. As a result, TAMs treated with let-7b inhibitors reduce angiogenesis and prostate carcinoma (PCa) cell mobility. Let-7b may play a vital role in regulating macrophage polarization, thus modulating the prognosis of prostate cancer.

Nanomedicine Strategies to Target Tumor-Associated Macrophages

PubMed Central

Binnemars-Postma, Karin; Storm, Gert; Prakash, Jai

2017-01-01

In recent years, the influence of the tumor microenvironment (TME) on cancer progression has been better understood. Macrophages, one of the most important cell types in the TME, exist in different subtypes, each of which has a different function. While classically activated M1 macrophages are involved in inflammatory and malignant processes, activated M2 macrophages are more involved in the wound-healing processes occurring in tumors. Tumor-associated macrophages (TAM) display M2 macrophage characteristics and support tumor growth and metastasis by matrix remodeling, neo-angiogenesis, and suppressing local immunity. Due to their detrimental role in tumor growth and metastasis, selective targeting of TAM for the treatment of cancer may prove to be beneficial in the treatment of cancer. Due to the plastic nature of macrophages, their activities may be altered to inhibit tumor growth. In this review, we will discuss the therapeutic options for the modulation and targeting of TAM. Different therapeutic strategies to deplete, inhibit recruitment of, or re-educate TAM will be discussed. Current strategies for the targeting of TAM using nanomedicine are reviewed. Passive targeting using different nanoparticle systems is described. Since TAM display a number of upregulated surface proteins compared to non-TAM, specific targeting using targeting ligands coupled to nanoparticles is discussed in detail. PMID:28471401

The Prolonged Life-Span of Alveolar Macrophages

PubMed Central

Murphy, Jaime; Summer, Ross; Wilson, Andrew A.; Kotton, Darrell N.; Fine, Alan

2008-01-01

To further examine the half-life of alveolar macrophages, chimeric CD 45.2 mice were generated through bone marrow transplantation of donor CD 45.1 cells. Before administration of donor cells, recipient mice were divided into two cohorts: the first cohort received total body irradiation; the second cohort also received irradiation—however, the thorax, head, and upper extremities were shielded with lead. Flow cytometric analysis was then performed on blood, peritoneal, and bronchoalveolar lavage cells over time to quantify engraftment. The data generated for the unshielded cohort of mice revealed a macrophage half-life of 30 days. In the shielded cohort, however, we found that by 8 months there was negligible replacement of recipient alveolar macrophages by donor cells, despite reconstitution of the blood and peritoneum by donor bone marrow. Consistent with these findings, the mean fluorescent intensity of alveolar macrophages remained stable over a 4-week period after in vivo PKH26 dye loading. Together, these data show that previous alveolar macrophage half-life studies were confounded by the fact that they did not account for the toxic effects of irradiation conditioning regimens, and demonstrate that the bone marrow does not significantly contribute to the alveolar macrophage compartment during steady-state conditions. PMID:18192503

Macrophage Depletion Ameliorates Peripheral Neuropathy in Aging Mice.

PubMed

Yuan, Xidi; Klein, Dennis; Kerscher, Susanne; West, Brian L; Weis, Joachim; Katona, Istvan; Martini, Rudolf

2018-05-09

Aging is known as a major risk factor for the structure and function of the nervous system. There is urgent need to overcome such deleterious effects of age-related neurodegeneration. Here we show that peripheral nerves of 24-month-old aging C57BL/6 mice of either sex show similar pathological alterations as nerves from aging human individuals, whereas 12-month-old adult mice lack such alterations. Specifically, nerve fibers showed demyelination, remyelination and axonal lesion. Moreover, in the aging mice, neuromuscular junctions showed features typical for dying-back neuropathies, as revealed by a decline of presynaptic markers, associated with α-bungarotoxin-positive postsynapses. In line with these observations were reduced muscle strengths. These alterations were accompanied by elevated numbers of endoneurial macrophages, partially comprising the features of phagocytosing macrophages. Comparable profiles of macrophages could be identified in peripheral nerve biopsies of aging persons. To determine the pathological impact of macrophages in aging mice, we selectively targeted the cells by applying an orally administered CSF-1R specific kinase (c-FMS) inhibitor. The 6-month-lasting treatment started before development of degenerative changes at 18 months and reduced macrophage numbers in mice by ∼70%, without side effects. Strikingly, nerve structure was ameliorated and muscle strength preserved. We show, for the first time, that age-related degenerative changes in peripheral nerves are driven by macrophages. These findings may pave the way for treating degeneration in the aging peripheral nervous system by targeting macrophages, leading to reduced weakness, improved mobility, and eventually increased quality of life in the elderly. SIGNIFICANCE STATEMENT Aging is a major risk factor for the structure and function of the nervous system. Here we show that peripheral nerves of 24-month-old aging mice show similar degenerative alterations as nerves from aging

Internalization of exogenous cystatin F supresses cysteine proteases and induces the accumulation of single-chain cathepsin L by multiple mechanisms.

PubMed

Colbert, Jeff D; Matthews, Stephen P; Kos, Janko; Watts, Colin

2011-12-09

Cystatin F is an unusual member of the cystatin family of protease inhibitors, which is made as an inactive dimer and becomes activated by proteolysis in the endo/lysosome pathway of the immune cells that produce it. However a proportion is secreted and can be taken up and activated by other cells. We show here that cystatin F acquired in this way induces a dramatic accumulation of the single-chain form of cathepsin L (CatL). Cystatin F was observed in the same cellular compartments as CatL and was tightly complexed with CatL as determined by co-precipitation studies. The observed accumulation of single-chain CatL was partly due to cystatin F-mediated inhibition of the putative single-chain to two-chain CatL convertase AEP/legumain and partly to general suppression of cathepsin activity. Thus, cystatin F stabilizes CatL leading to the dramatic accumulation of an inactive complex composed either of the single-chain or two-chain form depending on the capacity of cystatin F to inhibit AEP. Cross-transfer of cystatin F from one cell to another may therefore attenuate potentially harmful effects of excessive CatL activity while paradoxically, inducing accumulation of CatL protein. Finally, we confirmed earlier data (Beers, C., Honey, K., Fink, S., Forbush, K., and Rudensky, A. (2003) J. Exp. Med. 197, 169-179) showing a loss of CatL activity, but not of CatL protein, in macrophages activated with IFNγ. However, we found equivalent loss of CatL activity in wild type and cystatin F-null macrophages suggesting that an inhibitory activity other than cystatin F quenches CatL activity in activated macrophages.

Macrophages are critical effectors of antibody therapies for cancer.

PubMed

Weiskopf, Kipp; Weissman, Irving L

2015-01-01

Macrophages are innate immune cells that derive from circulating monocytes, reside in all tissues, and participate in many states of pathology. Macrophages play a dichotomous role in cancer, where they promote tumor growth but also serve as critical immune effectors of therapeutic antibodies. Macrophages express all classes of Fcγ receptors, and they have immense potential to destroy tumors via the process of antibody-dependent phagocytosis. A number of studies have demonstrated that macrophage phagocytosis is a major mechanism of action of many antibodies approved to treat cancer. Consequently, a number of approaches to augment macrophage responses to therapeutic antibodies are under investigation, including the exploration of new targets and development of antibodies with enhanced functions. For example, the interaction of CD47 with signal-regulatory protein α (SIRPα) serves as a myeloid-specific immune checkpoint that limits the response of macrophages to antibody therapies, and CD47-blocking agents overcome this barrier to augment phagocytosis. The response of macrophages to antibody therapies can also be enhanced with engineered Fc variants, bispecific antibodies, or antibody-drug conjugates. Macrophages have demonstrated success as effectors of cancer immunotherapy, and further investigation will unlock their full potential for the benefit of patients.

Macrophage polarization in virus-host interactions

USDA-ARS?s Scientific Manuscript database

Macrophage involvement in viral infections and antiviral states is common. However, this involvement has not been well-studied in the paradigm of macrophage polarization, which typically has been categorized by the dichotomy of classical (M1) and alternative (M2) statuses. Recent studies have reveal...

Expression analysis of G Protein-Coupled Receptors in mouse macrophages

PubMed Central

Lattin, Jane E; Schroder, Kate; Su, Andrew I; Walker, John R; Zhang, Jie; Wiltshire, Tim; Saijo, Kaoru; Glass, Christopher K; Hume, David A; Kellie, Stuart; Sweet, Matthew J

2008-01-01

Background Monocytes and macrophages express an extensive repertoire of G Protein-Coupled Receptors (GPCRs) that regulate inflammation and immunity. In this study we performed a systematic micro-array analysis of GPCR expression in primary mouse macrophages to identify family members that are either enriched in macrophages compared to a panel of other cell types, or are regulated by an inflammatory stimulus, the bacterial product lipopolysaccharide (LPS). Results Several members of the P2RY family had striking expression patterns in macrophages; P2ry6 mRNA was essentially expressed in a macrophage-specific fashion, whilst P2ry1 and P2ry5 mRNA levels were strongly down-regulated by LPS. Expression of several other GPCRs was either restricted to macrophages (e.g. Gpr84) or to both macrophages and neural tissues (e.g. P2ry12, Gpr85). The GPCR repertoire expressed by bone marrow-derived macrophages and thioglycollate-elicited peritoneal macrophages had some commonality, but there were also several GPCRs preferentially expressed by either cell population. Conclusion The constitutive or regulated expression in macrophages of several GPCRs identified in this study has not previously been described. Future studies on such GPCRs and their agonists are likely to provide important insights into macrophage biology, as well as novel inflammatory pathways that could be future targets for drug discovery. PMID:18442421

Expression analysis of G Protein-Coupled Receptors in mouse macrophages.

PubMed

Lattin, Jane E; Schroder, Kate; Su, Andrew I; Walker, John R; Zhang, Jie; Wiltshire, Tim; Saijo, Kaoru; Glass, Christopher K; Hume, David A; Kellie, Stuart; Sweet, Matthew J

2008-04-29

Monocytes and macrophages express an extensive repertoire of G Protein-Coupled Receptors (GPCRs) that regulate inflammation and immunity. In this study we performed a systematic micro-array analysis of GPCR expression in primary mouse macrophages to identify family members that are either enriched in macrophages compared to a panel of other cell types, or are regulated by an inflammatory stimulus, the bacterial product lipopolysaccharide (LPS). Several members of the P2RY family had striking expression patterns in macrophages; P2ry6 mRNA was essentially expressed in a macrophage-specific fashion, whilst P2ry1 and P2ry5 mRNA levels were strongly down-regulated by LPS. Expression of several other GPCRs was either restricted to macrophages (e.g. Gpr84) or to both macrophages and neural tissues (e.g. P2ry12, Gpr85). The GPCR repertoire expressed by bone marrow-derived macrophages and thioglycollate-elicited peritoneal macrophages had some commonality, but there were also several GPCRs preferentially expressed by either cell population. The constitutive or regulated expression in macrophages of several GPCRs identified in this study has not previously been described. Future studies on such GPCRs and their agonists are likely to provide important insights into macrophage biology, as well as novel inflammatory pathways that could be future targets for drug discovery.

Nicotinamide: a vitamin able to shift macrophage differentiation toward macrophages with restricted inflammatory features.

PubMed

Weiss, Ronald; Schilling, Erik; Grahnert, Anja; Kölling, Valeen; Dorow, Juliane; Ceglarek, Uta; Sack, Ulrich; Hauschildt, Sunna

2015-11-01

The differentiation of human monocytes into macrophages is influenced by environmental signals. Here we asked in how far nicotinamide (NAM), a vitamin B3 derivative known to play a major role in nicotinamide adenine dinucleotide (NAD)-mediated signaling events, is able to modulate monocyte differentiation into macrophages developed in the presence of granulocyte macrophage colony-stimulating factor (GM-MØ) or macrophage colony-stimulating factor (M-MØ). We found that GM-MØ undergo biochemical, morphological and functional modifications in response to NAM, whereas M-MØ were hardly affected. GM-MØ exposed to NAM acquired an M-MØ-like structure while the LPS-induced production of pro-inflammatory cytokines and COX-derived eicosanoids were down-regulated. In contrast, NAM had no effect on the production of IL-10 or the cytochrome P450-derived eicosanoids. Administration of NAM enhanced intracellular NAD concentrations; however, it did not prevent the LPS-mediated drain on NAD pools. In search of intracellular molecular targets of NAM known to be involved in LPS-induced cytokine and eicosanoid synthesis, we found NF-κB activity to be diminished. In conclusion, our data show that vitamin B3, when present during the differentiation of monocytes into GM-MØ, interferes with biochemical pathways resulting in strongly reduced pro-inflammatory features. © The Author(s) 2015.

The endoplasmic reticulum stress inducer thapsigargin enhances the toxicity of ZnO nanoparticles to macrophages and macrophage-endothelial co-culture.

PubMed

Chen, Gui; Shen, Yuexin; Li, Xiyue; Jiang, Qin; Cheng, Shanshan; Gu, Yuxiu; Liu, Liangliang; Cao, Yi

2017-03-01

It was recently shown that exposure to ZnO nanoparticles (NPs) could induce endoplasmic reticulum (ER) stress both in vivo and in vitro, but the role of ER stress in ZnO NP induced toxicity remains unclear. Because macrophages are sensitive to ER stress, we hypothesized that stressing macrophages with ER stress inducer could enhance the toxicity of ZnO NPs. In this study, the effects of ER stress inducer thapsigargin (TG) on the toxicity of ZnO NPs to THP-1 macrophages were investigated. The results showed that TG enhanced ZnO NP induced cytotoxicity as revealed by water soluble tetrazolium-1 (WST-1) and neutral red uptake assays, but not lactate dehydrogenase (LDH) assay. ZnO NPs dose-dependently enhanced the accumulation of intracellular Zn ions without the induction of reactive oxygen species (ROS), and the presence of TG did not significantly affect these effects. In the co-culture, exposure of THP-1 macrophages in the upper chamber to ZnO NPs and TG significantly reduced the viability of human umbilical vein endothelial cells (HUVECs) in the lower chamber, but the release of tumor necrosis factor α (TNFα) was not induced. In summary, our data showed that stressing THP-1 macrophages with TG enhanced the cytotoxicity of ZnO NPs to macrophages and macrophage-endothelial co-cultures. Copyright © 2017 Elsevier B.V. All rights reserved.

47 CFR 32.4550 - Retained earnings.

Code of Federal Regulations, 2010 CFR

2010-10-01

... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.4550 Retained earnings. (a) This account shall include the undistributed balance of retained earnings derived from the...

Macrophage Phenotype and Function in Different Stages of Atherosclerosis

PubMed Central

Tabas, Ira; Bornfeldt, Karin E.

2016-01-01

The remarkable plasticity and plethora of biological functions performed by macrophages have enticed scientists to study these cells in relation to atherosclerosis for more than 50 years, and major discoveries continue to be made today. It is now understood that macrophages play important roles in all stages of atherosclerosis, from initiation of lesions and lesion expansion, to necrosis leading to rupture and the clinical manifestations of atherosclerosis, to resolution and regression of atherosclerotic lesions. Lesional macrophages are derived primarily from blood monocytes, although recent research has shown that lesional macrophage-like cells can also be derived from smooth muscle cells. Lesional macrophages take on different phenotypes depending on their environment and which intracellular signaling pathways are activated. Rather than a few distinct populations of macrophages, the phenotype of the lesional macrophage is more complex and likely changes during the different phases of atherosclerosis and with the extent of lipid and cholesterol loading, activation by a plethora of receptors, and metabolic state of the cells. These different phenotypes allow the macrophage to engulf lipids, dead cells, and other substances perceived as danger signals; efflux cholesterol to HDL; proliferate and migrate; undergo apoptosis and death; and secrete a large number of inflammatory and pro-resolving molecules. This review article, part of the Compendium on Atherosclerosis, discusses recent advances in our understanding of lesional macrophage phenotype and function in different stages of atherosclerosis. With the increasing understanding of the roles of lesional macrophages, new research areas and treatment strategies are beginning to emerge. PMID:26892964

Alcoholic Fractions F5 and F6 from Withania somnifera Leaves Show a Potent Antileishmanial and Immunomodulatory Activities to Control Experimental Visceral Leishmaniasis

PubMed Central

Chandrasekaran, Sambamurthy; Veronica, Jalaja; Sundar, Shyam; Maurya, Radheshyam

2017-01-01

Visceral leishmaniasis (VL) causes fatal life-threatening disease, if left untreated. The current drugs have various limitations; hence, natural products from medicinal plants are being focused in search of new drugs to treat leishmaniasis. The aim of the present study was to evaluate the antileishmanial and immunomodulatory activities of F5 and F6 alcoholic fractions from Withania somnifera leaves and purified withaferin-A in Leishmania donovani-infected peritoneal macrophages and BALB/c mice. We observed that F5 (15 µg/mL), F6 (10 µg/mL), and withaferin-A (1.5 µM) reduce amastigote count in peritoneal macrophages and induce reactive oxygen species and significant decrease in IL-10 mRNA expression compared to control upon treatment. Subsequently, in vivo study mice were treated with F5 (25 and 50 mg/kg b.wt.), F6 (25 and 50 mg/kg b.wt.) orally, and withaferin-A (2 mg/kg b.wt.) intraperitoneally for 10 consecutive days and a drastic reduction in parasite burden in both spleen and liver were observed. The treatment resulted in the reduction in IL-10, IL-4, and TGF-β mRNA expression and a significant increase in IFN-γ/IL-10 expression ratio in the treated group compared to control. The humoral response of these alcoholic fractions and withaferin-A shows increased IgG2a levels when compared with IgG1 in treated mice. Taken together, our result concludes that withanolides in alcoholic fractions demonstrate a potent antileishmanial and immunomodulatory activities in experimental VL. PMID:28553635

Macrophages and Their Role in Atherosclerosis: Pathophysiology and Transcriptome Analysis

PubMed Central

Chistiakov, Dimitry A.; Nikiforov, Nikita G.

2016-01-01

Atherosclerosis can be regarded as a chronic inflammatory state, in which macrophages play different and important roles. Phagocytic proinflammatory cells populate growing atherosclerotic lesions, where they actively participate in cholesterol accumulation. Moreover, macrophages promote formation of complicated and unstable plaques by maintaining proinflammatory microenvironment. At the same time, anti-inflammatory macrophages contribute to tissue repair and remodelling and plaque stabilization. Macrophages therefore represent attractive targets for development of antiatherosclerotic therapy, which can aim to reduce monocyte recruitment to the lesion site, inhibit proinflammatory macrophages, or stimulate anti-inflammatory responses and cholesterol efflux. More studies are needed, however, to create a comprehensive classification of different macrophage phenotypes and to define their roles in the pathogenesis of atherosclerosis. In this review, we provide an overview of the current knowledge on macrophage diversity, activation, and plasticity in atherosclerosis and describe macrophage-based cellular tests for evaluation of potential antiatherosclerotic substances. PMID:27493969

Temporal and spatial distribution of macrophage phenotype markers in the foreign body response to glutaraldehyde-crosslinked gelatin hydrogels.

PubMed

Yu, Tony; Wang, Wenbo; Nassiri, Sina; Kwan, Thomas; Dang, Chau; Liu, Wei; Spiller, Kara L

2016-01-01

Currently, it is not well understood how changes in biomaterial properties affect the foreign body response (FBR) or macrophage behavior. Because failed attempts at biomaterial degradation by macrophages have been linked to frustrated phagocytosis, a defining feature of the FBR, we hypothesized that increased hydrogel crosslinking density (and decreased degradability) would exacerbate the FBR. Gelatin hydrogels were crosslinked with glutaraldehyde (0.05, 0.1, and 0.3%) and implanted subcutaneously in C57BL/6 mice over the course of 3 weeks. Interestingly, changes in hydrogel crosslinking did not affect the thickness of the fibrous capsule surrounding the hydrogels, expression of the pan-macrophage marker F480, expression of three macrophage phenotype markers (iNOS, Arg1, CD163), or expression of the myofibroblast marker aSMA, determined using semi-quantitative immunohistochemical analysis. With respect to temporal changes, the level of expression of the M1 marker (iNOS) remained relatively constant throughout the study, while the M2 markers Arg1 and CD163 increased over time. Expression of these M2 markers was highly correlated with fibrous capsule thickness. Differences in spatial distribution of staining also were noted, with the strongest staining for iNOS at the hydrogel surface and increasing expression of the myofibroblast marker aSMA toward the outer edge of the fibrous capsule. These results confirm previous reports that macrophages in the FBR exhibit characteristics of both M1 and M2 phenotypes. Understanding the effects (or lack of effects) of biomaterial properties on the FBR and macrophage phenotype may aid in the rational design of biomaterials to integrate with surrounding tissue.

Comparison of effects on macrophage cultures of glass fibre, glass powder, and chrysotile asbestos

PubMed Central

Beck, E. G.; Holt, P. F.; Manojlović, N.

1972-01-01

Beck, E. G., Holt, P. F., and Manojlović, N. (1972).Brit. J. industr. Med.,29, 280-286. Comparison of effects on macrophage cultures of glass fibre, glass powder, and chrysotile asbestos. The effects on macrophage cultures of glass fibre, glass powder, and chrysotile asbestos are compared. Glass fibre behaves like chrysotile in producing an increase in cell membrane permeability in cultured macrophages. This is demonstrable by the increase in lactic dehydrogenase activity in the supernatant fluid. The metabolism, measured by lactate production, is not reduced as it is when quartz is phagocytosed. Glass powder behaves like the inert dust corundum, producing little change in the number of cells stained by erythrosin B and a small increase in lactate dehydrogenase activity, both being in the range of the control. There is an increase in lactate production as a result of higher metabolism due to phagocytosis. Dusts may produce two basic effects, namely a toxic effect and change in cell membrane permeability. A non-specific effect on the cell membrane due to the slow and sometimes incomplete process of ingestion of long fibres is probably a function of the morphology, particularly the length of the fibres. A primary specific effect induced by some dusts immediately follows contact with the cell membrane. Images PMID:4339803

The role of the macrophage in wound repair. A study with hydrocortisone and antimacrophage serum.

PubMed Central

Leibovich, S. J.; Ross, R.

1975-01-01

The role of the monocyte/macrophage in wound repair has been investigated by studying the healing process in wounds depleted of this cell and/or its phagocytic activity. Hydrocortisone acetate (0.6 mg/g body weight) administered as a subcutaneous depot was used to induce a prolonged monocytopenia in guinea pigs, and antimacrophage serum (AMS) was used for local elimination of tissue macrophages. In vitro, the presence of complement, macrophages are rapidly lysed and used killed by AMS. In the absence of complement, AMS is not cytotoxic but potently inhibits adherence to and phagocytosis of opsonized erythrocytes by macrophages. AMS titers were obtained by observation of adherence and phagocytosis of opsonized erythrocytes in serial dilutions of AMS. Six groups of animals were studied: a) untreated animals, b)animals receiving daily subcutaneous injections of normal rabbit serum (NRS) around each wound, c)animals receiving daily subcutaneous AMS around each wound, d)animals receiving systemic hydrocortisone, e)animals receiving systemic hydrocortisone and daily injections of NRS around each wound, and f)animals receiving systemic hydrocortisone and daily AMS around each wound. Wounds consisted of a series of six linear incisions in the dorsal skin. Subcutaneous AMS alone has no effect on the number of circulating monocytes, nor was there any observable effect on the number or the phagocytic ability of wound macrophages. Fibrosis in these wounds was unaffected. Systemic hydrocortisone induced a prolonged monocytopenia. The macrophage level in the wounds of these monocytopenic animals was reduced to approximately one-third that of controls; the phagocytic activity of the monocytes/macrophages that did appear in these wounds was, however, similar to that of controls. Some inhibition of wound debridement was observed in these wounds, but fibrosis was virtually unaffected. Collagen synthesis, as judged morphometrically, was similar to that of control wounds at all stages

Btk Regulates Macrophage Polarization in Response to Lipopolysaccharide

PubMed Central

Ní Gabhann, Joan; Hams, Emily; Smith, Siobhán; Wynne, Claire; Byrne, Jennifer C.; Brennan, Kiva; Spence, Shaun; Kissenpfennig, Adrien; Johnston, James A.; Fallon, Padraic G.; Jefferies, Caroline A.

2014-01-01

Bacterial Lipopolysaccharide (LPS) is a strong inducer of inflammation and does so by inducing polarization of macrophages to the classic inflammatory M1 population. Given the role of Btk as a critical signal transducer downstream of TLR4, we investigated its role in M1/M2 induction. In Btk deficient (Btk −\\−) mice we observed markedly reduced recruitment of M1 macrophages following intraperitoneal administration of LPS. Ex vivo analysis demonstrated an impaired ability of Btk−/− macrophages to polarize into M1 macrophages, instead showing enhanced induction of immunosuppressive M2-associated markers in response to M1 polarizing stimuli, a finding accompanied by reduced phosphorylation of STAT1 and enhanced STAT6 phosphorylation. In addition to STAT activation, M1 and M2 polarizing signals modulate the expression of inflammatory genes via differential activation of transcription factors and regulatory proteins, including NF-κB and SHIP1. In keeping with a critical role for Btk in macrophage polarization, we observed reduced levels of NF-κB p65 and Akt phosphorylation, as well as reduced induction of the M1 associated marker iNOS in Btk−/− macrophages in response to M1 polarizing stimuli. Additionally enhanced expression of SHIP1, a key negative regulator of macrophage polarisation, was observed in Btk−/− macrophages in response to M2 polarizing stimuli. Employing classic models of allergic M2 inflammation, treatment of Btk −/− mice with either Schistosoma mansoni eggs or chitin resulted in increased recruitment of M2 macrophages and induction of M2-associated genes. This demonstrates an enhanced M2 skew in the absence of Btk, thus promoting the development of allergic inflammation. PMID:24465735

Impaired plasticity of macrophages in X-linked adrenoleukodystrophy.

PubMed

Weinhofer, Isabelle; Zierfuss, Bettina; Hametner, Simon; Wagner, Magdalena; Popitsch, Niko; Machacek, Christian; Bartolini, Barbara; Zlabinger, Gerhard; Ohradanova-Repic, Anna; Stockinger, Hannes; Köhler, Wolfgang; Höftberger, Romana; Regelsberger, Günther; Forss-Petter, Sonja; Lassmann, Hans; Berger, Johannes

2018-05-30

X-linked adrenoleukodystrophy is caused by ATP-binding cassette transporter D1 (ABCD1) mutations and manifests by default as slowly progressive spinal cord axonopathy with associated demyelination (adrenomyloneuropathy). In 60% of male cases, however, X-linked adrenoleukodystrophy converts to devastating cerebral inflammation and demyelination (cerebral adrenoleukodystrophy) with infiltrating blood-derived monocytes and macrophages and cytotoxic T cells that can only be stopped by allogeneic haematopoietic stem cell transplantation or gene therapy at an early stage of the disease. Recently, we identified monocytes/macrophages but not T cells to be severely affected metabolically by ABCD1 deficiency. Here we found by whole transcriptome analysis that, although monocytes of patients with X-linked adrenoleukodystrophy have normal capacity for macrophage differentiation and phagocytosis, they are pro-inflammatory skewed also in patients with adrenomyloneuropathy in the absence of cerebral inflammation. Following lipopolysaccharide activation, the ingestion of myelin debris, normally triggering anti-inflammatory polarization, did not fully reverse the pro-inflammatory status of X-linked adrenoleukodystrophy macrophages. Immunohistochemistry on post-mortem cerebral adrenoleukodystrophy lesions reflected the activation pattern by prominent presence of enlarged lipid-laden macrophages strongly positive for the pro-inflammatory marker co-stimulatory molecule CD86. Comparative analyses of lesions with matching macrophage density in cases of cerebral adrenoleukodystrophy and acute multiple sclerosis showed a similar extent of pro-inflammatory activation but a striking reduction of anti-inflammatory mannose receptor (CD206) and haemoglobin-haptoglobin receptor (CD163) expression on cerebral adrenoleukodystrophy macrophages. Accordingly, ABCD1-deficiency leads to an impaired plasticity of macrophages that is reflected in incomplete establishment of anti-inflammatory responses

Leishmania and the macrophage: a multifaceted interaction.

PubMed

Podinovskaia, Maria; Descoteaux, Albert

2015-01-01

Leishmania, the causative agent of leishmaniases, is an intracellular parasite of macrophages, transmitted to humans via the bite of its sand fly vector. This protozoan organism has evolved strategies for efficient uptake into macrophages and is able to regulate phagosome maturation in order to make the phagosome more hospitable for parasite growth and to avoid destruction. As a result, macrophage defenses such as oxidative damage, antigen presentation, immune activation and apoptosis are compromised whereas nutrient availability is improved. Many Leishmania survival factors are involved in shaping the phagosome and reprogramming the macrophage to promote infection. This review details the complexity of the host-parasite interactions and summarizes our latest understanding of key events that make Leishmania such a successful intracellular parasite.

Icm/Dot-Independent Entry of Legionella pneumophila into Amoeba and Macrophage Hosts

PubMed Central

Bandyopadhyay, Purnima; Xiao, Huifang; Coleman, Hope A.; Price-Whelan, Alexa; Steinman, Howard M.

2004-01-01

Legionella pneumophila, the causative agent of Legionnaires' disease, expresses a type IVB secretion apparatus that translocates bacterial proteins into amoeba and macrophage hosts. When stationary-phase cultures are used to infect hosts, the type IVB apparatus encoded by the icm/dot genes is required for entry, delay of phagosome-lysosome fusion, and intracellular multiplication within host cells. Null mutants with mutations in icm/dot genes are defective in these phenotypes. Here a new model is described in which hosts are infected with stationary-phase cultures that have been incubated overnight in pH 6.5 buffer. This model is called Ers treatment because it enhances the resistance to acid, hydrogen peroxide, and antibiotic stress beyond that of stationary-phase cultures. Following Ers treatment entry into amoeba and macrophage hosts does not require dotA, which is essential for Legionella virulence phenotypes when hosts are infected with stationary-phase cultures, dotB, icmF, icmV, or icmX. Defective host entry is also suppressed for null mutants with mutations in the KatA and KatB catalase-peroxidase enzymes, which are required for proper intracellular growth in amoeba and macrophage hosts. Ers treatment-induced suppression of defective entry is not associated with increased bacterial adhesion to host cells or with morphological changes in the bacterial envelope but is dependent on protein expression during Ers treatment. By using proteomic analysis, Ers treatment was shown to induce a protein predicted to contain eight tetratricopeptide repeats, a motif previously implicated in enhanced entry of L. pneumophila. Characterization of Ers treatment-dependent changes in expression is proposed as an avenue for identifying icm/dot-independent factors that function in the entry of Legionella into amoeba and macrophage hosts. PMID:15271914

The Phagocytic Function of Macrophage-Enforcing Innate Immunity and Tissue Homeostasis.

PubMed

Hirayama, Daisuke; Iida, Tomoya; Nakase, Hiroshi

2017-12-29

Macrophages are effector cells of the innate immune system that phagocytose bacteria and secrete both pro-inflammatory and antimicrobial mediators. In addition, macrophages play an important role in eliminating diseased and damaged cells through their programmed cell death. Generally, macrophages ingest and degrade dead cells, debris, tumor cells, and foreign materials. They promote homeostasis by responding to internal and external changes within the body, not only as phagocytes, but also through trophic, regulatory, and repair functions. Recent studies demonstrated that macrophages differentiate from hematopoietic stem cell-derived monocytes and embryonic yolk sac macrophages. The latter mainly give rise to tissue macrophages. Macrophages exist in all vertebrate tissues and have dual functions in host protection and tissue injury, which are maintained at a fine balance. Tissue macrophages have heterogeneous phenotypes in different tissue environments. In this review, we focused on the phagocytic function of macrophage-enforcing innate immunity and tissue homeostasis for a better understanding of the role of tissue macrophages in several pathological conditions.

Dysregulated Functions of Lung Macrophage Populations in COPD.

PubMed

Kapellos, Theodore S; Bassler, Kevin; Aschenbrenner, Anna C; Fujii, Wataru; Schultze, Joachim L

2018-01-01

Chronic obstructive pulmonary disease (COPD) is a diverse respiratory disease characterised by bronchiolitis, small airway obstruction, and emphysema. Innate immune cells play a pivotal role in the disease's progression, and in particular, lung macrophages exploit their prevalence and strategic localisation to orchestrate immune responses. To date, alveolar and interstitial resident macrophages as well as blood monocytes have been described in the lungs of patients with COPD contributing to disease pathology by changes in their functional repertoire. In this review, we summarise recent evidence from human studies and work with animal models of COPD with regard to altered functions of each of these myeloid cell populations. We primarily focus on the dysregulated capacity of alveolar macrophages to secrete proinflammatory mediators and proteases, induce oxidative stress, engulf microbes and apoptotic cells, and express surface and intracellular markers in patients with COPD. In addition, we discuss the differences in the responses between alveolar macrophages and interstitial macrophages/monocytes in the disease and propose how the field should advance to better understand the implications of lung macrophage functions in COPD.

Dysregulated Functions of Lung Macrophage Populations in COPD

PubMed Central

Bassler, Kevin; Aschenbrenner, Anna C.

2018-01-01

Chronic obstructive pulmonary disease (COPD) is a diverse respiratory disease characterised by bronchiolitis, small airway obstruction, and emphysema. Innate immune cells play a pivotal role in the disease's progression, and in particular, lung macrophages exploit their prevalence and strategic localisation to orchestrate immune responses. To date, alveolar and interstitial resident macrophages as well as blood monocytes have been described in the lungs of patients with COPD contributing to disease pathology by changes in their functional repertoire. In this review, we summarise recent evidence from human studies and work with animal models of COPD with regard to altered functions of each of these myeloid cell populations. We primarily focus on the dysregulated capacity of alveolar macrophages to secrete proinflammatory mediators and proteases, induce oxidative stress, engulf microbes and apoptotic cells, and express surface and intracellular markers in patients with COPD. In addition, we discuss the differences in the responses between alveolar macrophages and interstitial macrophages/monocytes in the disease and propose how the field should advance to better understand the implications of lung macrophage functions in COPD. PMID:29670919

E4F1 deficiency results in oxidative stress–mediated cell death of leukemic cells

PubMed Central

Hatchi, Elodie; Rodier, Genevieve; Lacroix, Matthieu; Caramel, Julie; Kirsh, Olivier; Jacquet, Chantal; Schrepfer, Emilie; Lagarrigue, Sylviane; Linares, Laetitia Karine; Lledo, Gwendaline; Tondeur, Sylvie; Dubus, Pierre

2011-01-01

The multifunctional E4F1 protein was originally discovered as a target of the E1A viral oncoprotein. Growing evidence indicates that E4F1 is involved in key signaling pathways commonly deregulated during cell transformation. In this study, we investigate the influence of E4F1 on tumorigenesis. Wild-type mice injected with fetal liver cells from mice lacking CDKN2A, the gene encoding Ink4a/Arf, developed histiocytic sarcomas (HSs), a tumor originating from the monocytic/macrophagic lineage. Cre-mediated deletion of E4F1 resulted in the death of HS cells and tumor regression in vivo and extended the lifespan of recipient animals. In murine and human HS cell lines, E4F1 inactivation resulted in mitochondrial defects and increased production of reactive oxygen species (ROS) that triggered massive cell death. Notably, these defects of E4F1 depletion were observed in HS cells but not healthy primary macrophages. Short hairpin RNA–mediated depletion of E4F1 induced mitochondrial defects and ROS-mediated death in several human myeloid leukemia cell lines. E4F1 protein is overexpressed in a large subset of human acute myeloid leukemia samples. Together, these data reveal a role for E4F1 in the survival of myeloid leukemic cells and support the notion that targeting E4F1 activities might have therapeutic interest. PMID:21708927

G-CSF regulates macrophage phenotype and associates with poor overall survival in human triple-negative breast cancer

PubMed Central

Hollmén, Maija; Karaman, Sinem; Schwager, Simon; Lisibach, Angela; Christiansen, Ailsa J.; Maksimow, Mikael; Varga, Zsuzsanna; Jalkanen, Sirpa; Detmar, Michael

2016-01-01

ABSTRACT Tumor-associated macrophages (TAMs) have been implicated in the promotion of breast cancer growth and metastasis, and a strong infiltration by TAMs has been associated with estrogen receptor (ER)-negative tumors and poor prognosis. However, the molecular mechanisms behind these observations are unclear. We investigated macrophage activation in response to co-culture with several breast cancer cell lines (T47D, MCF-7, BT-474, SKBR-3, Cal-51 and MDA-MB-231) and found that high granulocyte colony-stimulating factor (G-CSF) secretion by the triple-negative breast cancer (TNBC) cell line MDA-MB-231 gave rise to immunosuppressive HLA-DRlo macrophages that promoted migration of breast cancer cells via secretion of TGF-α. In human breast cancer samples (n = 548), G-CSF was highly expressed in TNBC (p < 0.001) and associated with CD163+ macrophages (p < 0.0001), poorer overall survival (OS) (p = 0.021) and significantly increased numbers of TGF-α+ cells. While G-CSF blockade in the 4T1 mammary tumor model promoted maturation of MHCIIhi blood monocytes and TAMs and significantly reduced lung metastasis, anti-CSF-1R treatment promoted MHCIIloF4/80hiMRhi anti-inflammatory TAMs and enhanced lung metastasis in the presence of high G-CSF levels. Combined anti-G-CSF and anti-CSF-1R therapy significantly increased lymph node metastases, possibly via depletion of the so-called “gate-keeper” subcapsular sinus macrophages. These results indicate that G-CSF promotes the anti-inflammatory phenotype of tumor-induced macrophages when CSF-1R is inhibited and therefore caution against the use of M-CSF/CSF-1R targeting agents in tumors with high G-CSF expression. PMID:27141367

Research notes : evaluation of open-graded "F" mixtures for water sensitivity.

DOT National Transportation Integrated Search

1993-12-01

In 1992, many "F" mixtures failed the Index of Retained Strength (IRS) used by ODOT to evaluate the water damage potential of asphalt concrete mixtures. Although "F" mixtures had difficulty passing the IRS test, ODOT engineers felt that the problem w...

Stainless hooks to bond lower lingual retainer.

PubMed

Durgekar, Sujala G; Nagaraj, K

2011-01-01

We introduced a simple and economical technique for precise placement of lower lingual retainers. Two stainless steel hooks made of 0.6mm wire are placed interdentally in the embrasure area between canine and lateral incisor bilaterally to lock the retainer wire in the correct position. Etch, rinse and dry the enamel surfaces with the retainer passively in place, then bond the retainer with light-cured adhesive. Hooks are simple to fabricate and eliminate the need for a transfer tray.

Granulocyte Macrophage-Colony Stimulating Factor-induced Zn Sequestration Enhances Macrophage Superoxide and Limits Intracellular Pathogen Survival

PubMed Central

Vignesh, Kavitha Subramanian; Landero Figueroa, Julio A.; Porollo, Aleksey; Caruso, Joseph A.; Deepe, George S.

2013-01-01

SUMMARY Macrophages possess numerous mechanisms to combat microbial invasion, including sequestration of essential nutrients, like Zn. The pleiotropic cytokine granulocyte macrophage-colony stimulating factor (GM-CSF) enhances antimicrobial defenses against intracellular pathogens such as Histoplasma capsulatum, but its mode of action remains elusive. We have found that GM-CSF activated infected macrophages sequestered labile Zn by inducing binding to metallothioneins (MTs) in a STAT3 and STAT5 transcription factor-dependent manner. GM-CSF upregulated expression of Zn exporters, Slc30a4 and Slc30a7 and the metal was shuttled away from phagosomes and into the Golgi apparatus. This distinctive Zn sequestration strategy elevated phagosomal H+ channel function and triggered reactive oxygen species (ROS) generation by NADPH oxidase. Consequently, H. capsulatum was selectively deprived of Zn, thereby halting replication and fostering fungal clearance. GM-CSF mediated Zn sequestration via MTs in vitro and in vivo in mice and in human macrophages. These findings illuminate a GM-CSF-induced Zn-sequestration network that drives phagocyte antimicrobial effector function. PMID:24138881

Involvement of Macrophages in the Pathogenesis of Familial Amyloid Polyneuropathy and Efficacy of Human iPS Cell-Derived Macrophages in Its Treatment

PubMed Central

Komohara, Yoshihiro; Takamatsu, Koutaro; Kakuma, Tatsuyuki; Tasaki, Masayoshi; Misumi, Yohei; Ueda, Mitsuharu; Ito, Takaaki; Senju, Satoru; Ando, Yukio

2016-01-01

We hypothesized that tissue-resident macrophages in familial amyloid polyneuropathy (FAP) patients will exhibit qualitative or quantitative abnormalities, that may accelerate transthyretin (TTR)-derived amyloid deposition. To evaluate this, we examined the number and subset of tissue-resident macrophages in heart tissue from amyloid-deposited FAP and control patients. In both FAP and control patients, tissue-resident macrophages in heart tissue were all Iba+/CD163+/CD206+ macrophages. However, the number of macrophages was significantly decreased in FAP patients compared with control patients. Furthermore, the proportion of intracellular TTR in CD14+ monocytes was reduced in peripheral blood compared with healthy donors. Based on these results, we next examined degradation and endocytosis of TTR in human induced pluripotent stem (iPS) cell-derived myeloid lineage cells (MLs), which function like macrophages. iPS-MLs express CD163 and CD206, and belong to the inhibitory macrophage category. In addition, iPS-MLs degrade both native and aggregated TTR in a cell-dependent manner in vitro. Further, iPS-MLs endocytose aggregated, and especially polymerized, TTR. These results suggest that decreased tissue-localized macrophages disrupt clearance of TTR-derived amyloid deposits, leading to progression of a pathological condition in FAP patients. To improve this situation, clinical application of pluripotent stem cell-derived MLs may be useful as an approach for FAP therapy. PMID:27695122

Mechanism of interleukin-13 production by granulocyte-macrophage colony-stimulating factor-dependent macrophages via protease-activated receptor-2.

PubMed

Yamaguchi, Rui; Yamamoto, Takatoshi; Sakamoto, Arisa; Ishimaru, Yasuji; Narahara, Shinji; Sugiuchi, Hiroyuki; Hirose, Eiji; Yamaguchi, Yasuo

2015-06-01

Granulocyte-macrophage colony-stimulating factor (GM-CSF) promotes classically activated M1 macrophages. GM-CSF upregulates protease-activated receptor-2 (PAR-2) protein expression and activation of PAR-2 by human neutrophil elastase (HNE) regulates cytokine production. This study investigated the mechanism of PAR-2-mediated interleukin (IL)-13 production by GM-CSF-dependent macrophages stimulated with HNE. Adherent macrophages were obtained from primary cultures of human mononuclear cells. After stimulation with HNE to activate the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway, IL-13 mRNA and protein levels were assessed by the reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. PAR-2 protein was detected in GM-CSF-dependent macrophages by Western blotting. Unexpectedly, PD98059 (an ERK1 inhibitor) increased IL-13 production, even at higher concentrations. Interestingly, U0126 (an ERK1/2 inhibitor) reduced IL-13 production in a concentration-dependent manner. Neither SB203580 (a p38alpha/p38beta inhibitor) nor BIRB796 (a p38gamma/p38delta inhibitor) affected IL-13 production, while TMB-8 (a calcium chelator) diminished IL-13 production. Stimulation with HNE promoted the production of IL-13 (a Th2 cytokine) by GM-CSF-dependent M1 macrophages. PAR-2-mediated IL-13 production may be dependent on the Ca(2+)/ERK2 signaling pathway. Copyright © 2015 Elsevier Inc. All rights reserved.

MTOR Suppresses Environmental Particle-Induced Inflammatory Response in Macrophages.

PubMed

Li, Zhouyang; Wu, Yinfang; Chen, Hai-Pin; Zhu, Chen; Dong, Lingling; Wang, Yong; Liu, Huiwen; Xu, Xuchen; Zhou, Jiesen; Wu, Yanping; Li, Wen; Ying, Songmin; Shen, Huahao; Chen, Zhi-Hua

2018-04-15

Increasing toxicological and epidemiological studies have demonstrated that ambient particulate matter (PM) could cause adverse health effects including inflammation in the lung. Alveolar macrophages represent a major type of innate immune responses to foreign substances. However, the detailed mechanisms of inflammatory responses induced by PM exposure in macrophages are still unclear. We observed that coarse PM treatment rapidly activated mechanistic target of rapamycin (MTOR) in mouse alveolar macrophages in vivo, and in cultured mouse bone marrow-derived macrophages, mouse peritoneal macrophages, and RAW264.7 cells. Pharmacological inhibition or genetic knockdown of MTOR in bone marrow-derived macrophages leads to an amplified cytokine production upon PM exposure, and mice with specific knockdown of MTOR or ras homolog enriched in brain in myeloid cells exhibit significantly aggregated airway inflammation. Mechanistically, PM activated MTOR through modulation of ERK, AKT serine/threonine kinase 1, and tuberous sclerosis complex signals, whereas MTOR deficiency further enhanced the PM-induced necroptosis and activation of subsequent NF κ light-chain-enhancer of activated B cells (NFKB) signaling. Inhibition of necroptosis or NFKB pathways significantly ameliorated PM-induced inflammatory response in MTOR-deficient macrophages. The present study thus demonstrates that MTOR serves as an early adaptive signal that suppresses the PM-induced necroptosis, NFKB activation, and inflammatory response in lung macrophages, and suggests that activation of MTOR or inhibition of necroptosis in macrophages may represent novel therapeutic strategies for PM-related airway disorders. Copyright © 2018 by The American Association of Immunologists, Inc.

Novel interactions between erythroblast macrophage protein and cell migration.

PubMed

Javan, Gulnaz T; Can, Ismail; Yeboah, Fred; Lee, Youngil; Soni, Shivani

2016-09-01

Erythroblast macrophage protein is a novel protein known to mediate attachment of erythroid cells to macrophages to form erythroblastic islands in bone marrow during erythropoiesis. Emp-null macrophages are small with round morphologies, and lack cytoplasmic projections which imply immature structure. The role of Emp in macrophage development and function is not fully elucidated. Macrophages perform varied functions (e.g. homeostasis, erythropoiesis), and are implicated in numerous pathophysiological conditions such as cellular malignancy. The objective of the current study is to investigate the interaction of Emp with cytoskeletal- and cell migration-associated proteins involved in macrophage functions. A short hairpin RNA lentiviral system was use to down-regulate the expression of Emp in macrophage cells. A cell migration assay revealed that the relocation of macrophages was significantly inhibited when Emp expression was decreased. To further analyze changes in gene expression related to cell motility, PCR array was performed by down-regulating Emp expression. The results indicated that expression of mitogen-activated protein kinase 1 and thymoma viral proto-oncogene 1 were significantly higher when Emp was down-regulated. The results implicate Emp in abnormal cell motility, thus, warrants to assess its role in cancer where tumor cell motility is required for invasion and metastasis. Copyright © 2016 Elsevier Inc. All rights reserved.

3,4-dichloropropionaniline suppresses normal macrophage function.

PubMed

Ustyugova, Irina V; Frost, Laura L; Van Dyke, Knox; Brundage, Kathleen M; Schafer, Rosana; Barnett, John B

2007-06-01

Macrophages are a critical part of the innate immune response and natural surveillance mechanisms. As such, proper macrophage function is crucial for engulfing bacterial pathogens through phagocytosis and destroying them by generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). The production of a number of cytokines by macrophages, such as tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, and IL-6, plays an important role in the initiation of the acquired immune response creating an inflammatory environment favorable for fighting a bacterial infection. 3,4-Dichloropropionaniline (DCPA) suppresses several inflammatory parameters, including TNF-alpha production through a mechanism where nuclear factor-kappaB (NF-kappaB)-DNA binding is inhibited but not entirely abrogated. The goal of the present study was to evaluate the effects of DCPA on the inflammatory mediators of macrophages, including ROS and RNS in both murine peritoneal exudate cells and the human monocytic cell line, THP-1. The ability to perform phagocytosis and directly kill Listeria monocytogenes was also assessed. The results indicate that DCPA decreases the ability of both types of macrophages to phagocytize beads and generate both types of reactive species, which was correlated with a decrement in listericidal activity. These results demonstrate that DCPA has profound effects on macrophage function and provide insight into the potential mechanisms of immunosuppression by DCPA.

The significance of macrophage phenotype in cancer and biomaterials

DOE PAGES

Bygd, Hannah C.; Forsmark, Kiva D.; Bratlie, Kaitlin M.

2014-11-25

Macrophages have long been known to exhibit heterogeneous and plastic phenotypes. They show functional diversity with roles in homeostasis, tissue repair, immunity and disease. There exists a spectrum of macrophage phenotypes with varied effector functions, molecular determinants, cytokine and chemokine profiles, as well as receptor expression. In tumor microenvironments, the subset of macrophages known as tumor-associated macrophages generates byproducts that enhance tumor growth and angiogenesis, making them attractive targets for anti-cancer therapeutics. With respect to wound healing and the foreign body response, there is a necessity for balance between pro-inflammatory, wound healing, and regulatory macrophages in order to achieve successfulmore » implantation of a scaffold for tissue engineering. In this review, we discuss the multitude of ways macrophages are known to be important in cancer therapies and implanted biomaterials.« less

In vitro effects of nanosized diamond particles on macrophages.

PubMed

Shkurupy, V A; Arkhipov, S A; Neshchadim, D V; Akhramenko, E S; Troitskii, A V

2015-02-01

The effects of synthetic diamond nanoparticles (4-6 nm) on mouse macrophage biotropism and biocompatibility and the modulation of the macrophage functions (expression of IL-1α, TNF-α, GM-CSF, bFGF, and TGF-β) by nanoparticles in different concentrations were studied in vitro during exposure of different duration. Macrophage endocytosis of nanodiamonds increased with increasing the concentration of nanoparticles in culture and incubation time. Nanodiamonds exhibited high biotropism and biocompatibility towards macrophages; in doses of 10-20 μg/ml, they induced expression of GM-CSF and TGF-β, inhibited expression of bFGF, and did not stimulate IL-1α and TNF-α. These data indicate that nanodiamond capture by macrophages in the studied experimental model led to modulation of the functional status of macrophages that determine their capacity to stimulate reparative processes without increasing proinflammatory and profibrogenic status.

Macrophages in Progressive Human Immunodeficiency Virus/Simian Immunodeficiency Virus Infections

PubMed Central

DiNapoli, Sarah R.; Hirsch, Vanessa M.

2016-01-01

The cells that are targeted by primate lentiviruses (HIV and simian immunodeficiency virus [SIV]) are of intense interest given the renewed effort to identify potential cures for HIV. These viruses have been reported to infect multiple cell lineages of hematopoietic origin, including all phenotypic and functional CD4 T cell subsets. The two most commonly reported cell types that become infected in vivo are memory CD4 T cells and tissue-resident macrophages. Though viral infection of CD4 T cells is routinely detected in both HIV-infected humans and SIV-infected Asian macaques, significant viral infection of macrophages is only routinely observed in animal models wherein CD4 T cells are almost entirely depleted. Here we review the roles of macrophages in lentiviral disease progression, the evidence that macrophages support viral replication in vivo, the animal models where macrophage-mediated replication of SIV is thought to occur, how the virus can interact with macrophages in vivo, pathologies thought to be attributed to viral replication within macrophages, how viral replication in macrophages might contribute to the asymptomatic phase of HIV/SIV infection, and whether macrophages represent a long-lived reservoir for the virus. PMID:27307568

Blood vessel control of macrophage maturation promotes arteriogenesis in ischemia.

PubMed

Krishnasamy, Kashyap; Limbourg, Anne; Kapanadze, Tamar; Gamrekelashvili, Jaba; Beger, Christian; Häger, Christine; Lozanovski, Vladimir J; Falk, Christine S; Napp, L Christian; Bauersachs, Johann; Mack, Matthias; Haller, Hermann; Weber, Christian; Adams, Ralf H; Limbourg, Florian P

2017-10-16

Ischemia causes an inflammatory response that is intended to restore perfusion and homeostasis yet often aggravates damage. Here we show, using conditional genetic deletion strategies together with adoptive cell transfer experiments in a mouse model of hind limb ischemia, that blood vessels control macrophage differentiation and maturation from recruited monocytes via Notch signaling, which in turn promotes arteriogenesis and tissue repair. Macrophage maturation is controlled by Notch ligand Dll1 expressed in vascular endothelial cells of arteries and requires macrophage canonical Notch signaling via Rbpj, which simultaneously suppresses an inflammatory macrophage fate. Conversely, conditional mutant mice lacking Dll1 or Rbpj show proliferation and transient accumulation of inflammatory macrophages, which antagonizes arteriogenesis and tissue repair. Furthermore, the effects of Notch are sufficient to generate mature macrophages from monocytes ex vivo that display a stable anti-inflammatory phenotype when challenged with pro-inflammatory stimuli. Thus, angiocrine Notch signaling fosters macrophage maturation during ischemia.Molecular mechanisms of macrophage-mediated regulation of artery growth in response to ischemia are poorly understood. Here the authors show that vascular endothelium controls macrophage maturation and differentiation via Notch signaling, which in turn promotes arteriogenesis and ischemic tissue recovery.

17 CFR 256.215 - Appropriated retained earnings.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Appropriated retained earnings... UTILITY HOLDING COMPANY ACT OF 1935 Liabilities and Other Credit Accounts § 256.215 Appropriated retained earnings. This account shall include the amount of retained earnings which has been appropriated or set...

The Upregulation of Integrin αDβ2 (CD11d/CD18) on Inflammatory Macrophages Promotes Macrophage Retention in Vascular Lesions and Development of Atherosclerosis.

PubMed

Aziz, Moammir H; Cui, Kui; Das, Mitali; Brown, Kathleen E; Ardell, Christopher L; Febbraio, Maria; Pluskota, Elzbieta; Han, Juying; Wu, Huaizhu; Ballantyne, Christie M; Smith, Jonathan D; Cathcart, Martha K; Yakubenko, Valentin P

2017-06-15

Macrophage accumulation is a critical step during development of chronic inflammation, initiating progression of many devastating diseases. Leukocyte-specific integrin α D β 2 (CD11d/CD18) is dramatically upregulated on macrophages at inflammatory sites. Previously we found that CD11d overexpression on cell surfaces inhibits in vitro cell migration due to excessive adhesion. In this study, we have investigated how inflammation-mediated CD11d upregulation contributes to macrophage retention at inflammatory sites during atherogenesis. Atherosclerosis was evaluated in CD11d -/- /ApoE -/- mice after 16 wk on a Western diet. CD11d deficiency led to a marked reduction in lipid deposition in aortas and isolated macrophages. Macrophage numbers in aortic sinuses of CD11d -/- mice were reduced without affecting their apoptosis and proliferation. Adoptive transfer of fluorescently labeled wild-type and CD11d -/- monocytes into ApoE -/- mice demonstrated similar recruitment from circulation, but reduced accumulation of CD11d -/- macrophages within the aortas. Furthermore, CD11d expression was significantly upregulated on macrophages in atherosclerotic lesions and M1 macrophages in vitro. Interestingly, expression of the related ligand-sharing integrin CD11b was not altered. This difference defines their distinct roles in the regulation of macrophage migration. CD11d-deficient M1 macrophages demonstrated improved migration in a three-dimensional fibrin matrix and during resolution of peritoneal inflammation, whereas migration of CD11b -/- M1 macrophages was not affected. These results prove the contribution of high densities of CD11d to macrophage arrest during atherogenesis. Because high expression of CD11d was detected in several inflammation-dependent diseases, we suggest that CD11d/CD18 upregulation on proinflammatory macrophages may represent a common mechanism for macrophage retention at inflammatory sites, thereby promoting chronic inflammation and disease development

Intracellular Survival and Persistence of Chlamydia muridarum Is Determined by Macrophage Polarization

PubMed Central

Gracey, Eric; Lin, Aifeng; Akram, Ali; Chiu, Basil; Inman, Robert D.

2013-01-01

Macrophages can display a number of distinct phenotypes, known collectively as polarized macrophages. The best defined of these phenotypes are the classically-activated, interferon gamma (IFNγ)/LPS induced (M1) and alternatively-activated, IL-4 induced (M2) macrophages. The goal of this study is to characterize macrophage- Chlamydia interactions in the context of macrophage polarization. Here we use Chlamydia muridarum and murine bone-marrow derived macrophages to show Chlamydia does not induce M2 polarization in macrophages as a survival strategy. Unexpectedly, the infection of macrophages was silent with no upregulation of M1 macrophage-associated genes. We further demonstrate that macrophages polarized prior to infection have a differential capacity to control Chlamydia . M1 macrophages harbor up to 40-fold lower inclusion forming units (IFU) than non-polarized or M2 polarized macrophages. Gene expression analysis showed an increase in 16sRNA in M2 macrophages with no change in M1 macrophages. Suppressed Chlamydia growth in M1 macrophages correlated with the induction of a bacterial gene expression profile typical of persistence as evident by increased Euo expression and decreased Omp1 and Tal expression. Observations of permissive Chlamydia growth in non-polarized and M2 macrophages and persistence in M1 macrophages were supported through electron microscopy. This work supports the importance of IFNγ in the innate immune response to Chlamydia . However, demonstration that the M1 macrophages, despite an antimicrobial signature, fail to eliminate intracellular Chlamydia supports the notion that host–pathogen co-evolution has yielded a pathogen that can evade cellular defenses against this pathogen, and persist for prolonged periods of time in the host. PMID:23967058

Infectivity of five different types of macrophages by Leishmania infantum.

PubMed

Maia, C; Rolão, N; Nunes, M; Gonçalves, L; Campino, L

2007-08-01

Leishmania are intracellular parasites that multiply as the amastigote form in the macrophages of their vertebrate hosts. Since vaccines against leishmaniases are still under development, the control of these diseases relies on prompt diagnosis and chemotherapy in infected humans as well as in dogs, which are the main reservoir of Leishmania infantum, in Mediterranean countries. To establish the macrophage type to be used as an in vitro model for antileishmanial chemotherapeutic studies, we analysed the susceptibility of human peripheral blood derived macrophages, macrophages derived from mouse bone marrow, mouse peritoneal macrophages and macrophages differentiated from cell lines U-937 and DH82 to infection by two L. infantum strains, one obtained from a human leishmanial infection and other from a canine infection. Both strains displayed comparable behaviour in their capacity of infecting the different macrophage types. Human peripheral blood macrophages and DH82 cells were less infectable by both strains. U-937, mouse peritoneal macrophages and mouse bone marrow derived macrophages are the most active cells to phagocytose the parasites. However, U-937 cell line appears to be the most useful as Leishmania infection model providing an unlimited source of homogeneous host cells with reproducibility of the results, is less time consuming, less expensive and tolerate high doses of first line drugs for human and canine visceral leishmaniasis treatment.

Adipose tissue macrophages in non-rodent mammals: a comparative study.

PubMed

Ampem, Grace; Azegrouz, Hind; Bacsadi, Árpád; Balogh, Lajos; Schmidt, Susanne; Thuróczy, Julianna; Röszer, Tamás

2016-02-01

The stromal vascular fraction (SVF) of adipose tissue in rodents and primates contains mesenchymal stem cells and immune cells. SVF cells have complex metabolic, immune and endocrine functions with biomedical impact. However, in other mammals, the amount of data on SVF stem cells is negligible and whether the SVF hosts immune cells is unknown. In this study, we show that the SVF is rich in immune cells, with a dominance of adipose tissue macrophages (ATMs) in cattle (Bos primigenius taurus), domestic goat (Capra aegagrus hircus), domestic sheep (Ovis aries), domestic cat (Felis catus) and domestic dog (Canis familiaris). ATMs of these species are granulated lysosome-rich cells with lamellipodial protrusions and express the lysosome markers acid phosphatase 5 (ACP-5) and Mac-3/Lamp-2. Using ACP-5 and Mac-3/Lamp-2 as markers, we additionally detected ATMs in other species, such as the domestic horse (Equus ferus caballus), wild boar (Sus scrofa) and red fox (Vulpes vulpes). Feline and canine ATMs also express the murine macrophage marker F4/80 antigen. In the lean condition, the alternative macrophage activation marker CD206 is expressed by feline and canine ATMs and arginase-1 by feline ATMs. Obesity is associated with interleukin-6 and interferon gamma expression and with overt tyrosine nitration in both feline and canine ATMs. This resembles the obesity-induced phenotype switch of murine and human ATMs. Thus, we show, for the first time, that the presence of ATMs is a general trait of mammals. The interaction between the adipose cells and SVF immune cells might be evolutionarily conserved among mammals.

Cancer Metastasis: Perivascular Macrophages Under Watch.

PubMed

Kadioglu, Ece; De Palma, Michele

2015-09-01

TIE2-expressing macrophages cluster around blood vessels and sustain tumor angiogenesis. Harney and colleagues now use live imaging of mouse mammary tumors to show that these perivascular macrophages also promote the transient opening of tumor blood vessels to facilitate hematogenous cancer cell dissemination and metastasis. ©2015 American Association for Cancer Research.

[Macrophage colony stimulating factor enhances non-small cell lung cancer invasion and metastasis by promoting macrophage M2 polarization].

PubMed

Li, Y J; Yang, L; Wang, L P; Zhang, Y

2017-06-23

Objective: To investigate the key cytokine which polarizes M2 macrophages and promotes invasion and metastasis in non-small cell lung cancer (NSCLC). Methods: After co-culture with A549 cells in vitro, the proportion of CD14(+) CD163(+) M2 macrophages in monocytes and macrophage colony stimulating factor (M-CSF) levels in culture supernatant were detected by flow cytometry, ELISA assay and real-time qPCR, respectively. The effects of CD14(+) CD163(+) M2 macrophages on invasion of A549 cells and angiogenesis of HUVEC cells were measured by transwell assay and tubule formation assay, respectively. The clinical and prognostic significance of M-CSF expression in NSCLC was further analyzed. Results: The percentage of CD14(+) CD163(+) M2 macrophages in monocytes and the concentration of M-CSF in the supernatant followed by co-culture was (12.03±0.46)% and (299.80±73.76)pg/ml, respectively, which were significantly higher than those in control group [(2.80±1.04)% and (43.07±11.22)pg/ml, respectively, P < 0.05]. Human recombinant M-CSF promoted M2 polarization of macrophages in vitro . M2 macrophages enhanced the invasion of A549 cells (66 cells/field vs. 26 cells/field) and the angiogenesis of HUVEC cells (22 tubes/field vs. 8 tubes/field). The mRNA expression of M-CSF in stage Ⅰ-Ⅱ patients (16.23±4.83) was significantly lower than that in stage Ⅲ-Ⅳ (53.84±16.08; P <0.05). M-CSF levels were associated with poorer overall survival and disease-free survival in NSCLC patients ( P <0.05). Conclusions: Tumor-derived M-CSF can induce CD14(+) CD163(+) M2 polarization of macrophages, which can further promote the metastasis and angiogenesis of NSCLC. M-CSF could be used as a potential therapeutic target of NSCLC.

SHP-1-dependent macrophage differentiation exacerbates virus-induced myositis.

PubMed

Watson, Neva B; Schneider, Karin M; Massa, Paul T