Murine Macrophage-like Cell Line RAW Research Articles

Elucidation of regulatory mechanisms in the activation of dendritic cells by combined stimuli with PRR ligands and sulfated polysaccharide fucoidan

Abstract Fucoidan, a series of natural high-molecular weight sulfated polysaccharides derived from brown algae, has been reported to have various physiological effects such as antitumor, antiviral, and immunomodulatory activities. In a previous study, we demonstrated that fucoidan from Cladosiphon okamuranus (Okinawamozuku) was effectively activate murine macrophage-like cell line RAW264 in synergistic action with dectin-1-stimulating beta-glucan from Saccharomyces cerevisiae. In this study, we further examined their synergistic mode of action of Okinawamozuku-derived fucoidan in cooperate with pathogen stimulation in terms of dendritic cell activation. After myeloid dendritic cells (mDC) and plasmacytoid dendritic cells (pDC) were differentiated by culturing bone marrow cells isolated from C57BL/6J mice with Flt3 ligand, cytokine production upon stimulation with fucoidan and various pathogen components (pattern recognition receptor, PRR ligands) was measured. As the results, fucoidan alone enhanced the production of interferon (IFN)-gamma by the Flt3-L-induced mixed BMDCs, and besides, fucoidan synergistically augmented IFN-gamma production with Pam3CSK4 (bacterial TLR1/TLR2 ligand) or Poly(I:C)/LyoVec (viral RIG-I ligand). On the other hand, their IFN-alpha productions were reinforced with Poly(I:C) (viral TLR3 ligand), ODN1585 (viral TLR9 ligand) and Poly(I:C)/LyoVec, although no synergic enhancement by fucoidan was observed. These results suggested that fucoidan was extremely effective in activating dendritic cells, which play a central role in the regulation of immune function to eliminate infectious pathogens. Supported by grants from JSPS KAKENHI (JP21K05423)

Pal Affects the Proliferation in Macrophages and Virulence of Brucella, and as Mucosal Adjuvants, Provides an Effective Protection to Mice Against Salmonella Enteritidis.

The purpose of this study was to elucidate the roles of peptidoglycan-associated lipoprotein (Pal protein) in the proliferation of Brucella in macrophage and bacterial virulence, and to evaluate the immune effect of Pal protein to Salmonella enteritidis. Murine macrophage-like cell line Raw264.7 was stimulated by recombinant Pal protein, and the expression of TNF-α and IFN-γ were up-regulated, but not it of IL-1β and IL-6. The macrophages infection and in vitro simulated stress assays showed that deletion of pal gene reduced the proliferation of Brucella in macrophages, the survival in acidic, oxidative and polymyxin B-contained environment. The mice infection assay showed that mice challenged with the pal mutant strain were found to have more severe splenomegaly, but less bacterial load. After oral immunization of mice, Pal protein induced a higher titer of mucosal and humoral antibody (IgA and IgG) against heat-killed Salmonella enteritidis, and a stronger Th1 cellular immune response. The challengte experiments showed Pal protein elevated the survival rate and reduced the bacterial load of spleens in immunized mice. In conclusion, our results revealed the important roles of pal gene in Brucella virulence, and Pal protein was a potentially valuable adjuvant against mucosal pathogens, such as Salmonella enteritidis.

The anti-inflammatic activity of a sulfated polysaccharide Fucoidan in innate immune cells

Abstract Fucoidan is a series of natural sulfated polysaccharides derived from brown seaweeds and have reported to possess various biological activities such as anti-tumor, anti-virus, and immuno-modulatory effects. In previous study, we revealed that fucoidan derived from Cladosiphon okamuranus activated murine macrophage-like cell line RAW264 cooperatively with Zymosan, a Saccharomyces cerevisiae-derived β-glucan. On the other hand, several reports demonstrated that fucoidan inhibited lipopolysaccharide (LPS)-induced production of nitrogen oxide (NO) and inflammatory cytokines by RAW264 cells. Therefore, in this study, we investigated the potential of fucoidan derived from Undaria pinnatifida to regulate the excessive activation of RAW264 cells in response to overstimulation with pathogen components. RAW264 cells were inoculated at 20000 cells/well in 96-well culture plates, and after a recovery culture for 24 hr, the cells were treated with fucoidan with or without appropriate concentrations of each ligand for pattern recognition receptors (PRRs) including Toll-like receptors (TLRs). Whereas the production of NO was significantly enhanced with fucoidan alone, it was dose-dependently inhibited by fucoidan under stimulation with Pam3CSK4 (TLR1/TLR2 ligand), heat killed Listeria monocytogenes (HKLM, TLR2 ligand), LPS (TLR4 ligand), Pam2CGDPKHPKSF (FSL-1, TLR2/TLR6 ligand). These results suggested that fucoidan have beneficial ability to alleviate excessive inflammatory reaction during pathogenic infection and maintain suitable immune balance. Supported by Laboratory of Analytical Food Immunoscience belonging YM is a donated fund laboratory established in Faculty of Agriculture, Kyushu University by Ventuno Co., Ltd.

Activin a inhibits foam cell formation and up-regulates ABCA1 and ABCG1 expression through Alk4-Smad signaling pathway in RAW 264.7 macrophages

BackgroundActivin A has been reported to play important roles in the pathogenesis of atherosclerosis. The purpose of this study is to investigate the effects of activin A on oxidized low-density lipoprotein (ox-LDL)-induced foam cell formation and explore the underlying molecular mechanisms in murine macrophage-like cell line RAW 264.7. MethodsThe effects of activin A on Dil-labeled ox-LDL uptake were examined by confocal microscopy and flow cytometry analysis. The mRNA and protein levels of cholesterol receptors were analyzed by RT-qPCR and western blot analysis, respectively. To investigate whether activin receptor-like kinase 4 (Alk4) is required for activin A-mediated cellular effects, cells were pre-treated with SB-431542. The involvement of Smad2, Smad3 and Smad4 was confirmed by transfection with specific small interfering RNAs (siRNAs). ResultsActivin A inhibits ox-ldl-induced foam cell formation and class A scavenger receptors (SR‐A) expression, while up-regulates ATP-binding cassette transporter A1 (ABCA1) and ABCG1 expression in RAW 264.7 macrophages. Pre-treatment with SB-431542 abolished activin A-mediated anti-atherogenic effect. Knockdown of Smad2 reversed activin A-induced inhibition of ox-LDL uptake and SR-A expression. However, knockdown of Smad3 or Smad4 did not have such effect. Meanwhile, knockdown of either Smad2, Smad3 or Smad4 reversed the activin A-induced up-regulation of ABCA1 and ABCG1. ConclusionsOur study provides novel evidence that activin A may exert anti-atherogenic effects through Alk4-Smad signaling pathway in RAW 264.7 macrophages.

Genome-guided investigation of anti-inflammatory sesterterpenoids with 5-15 trans-fused ring system from phytopathogenic fungi.

Fungal terpenoids catalyzed by bifunctional terpene synthases (BFTSs) possess interesting bioactive and chemical properties. In this study, an integrated approach of genome mining, heterologous expression, and in vitro enzymatic activity assay was used, and these identified a unique BFTS sub-clade critical to the formation of a 5-15 trans-fused bicyclic sesterterpene preterpestacin I (1). The 5-15 bicyclic BFTS gene clusters were highly conserved but showed relatively wide phylogenetic distribution across several species of the diverged fungal classes Dothideomycetes and Sordariomycetes. Further genomic organization analysis of these homologous biosynthetic gene clusters from this clade revealed a glycosyltransferase from the graminaceous pathogen Bipolaris sorokiniana isolate BS11134, which was absent in other 5-15 bicyclic BFTS gene clusters. Targeted isolation guided by BFTS gene deletion led to the identification of two new sesterterpenoids (4, and 6) from BS11134. Compounds 2 and 4 showed moderate effects on LPS-induced nitrous oxide production in the murine macrophage-like cell line RAW264.7 with in vitro inhibition rates of 36.6 ± 2.4% and 24.9 ± 2.1% at 10 μM, respectively. The plausible biosynthetic pathway of these identified compounds was proposed as well. This work revealed that phytopathogenic fungi can serve as important sources of active terpenoids via systematic analysis of the genomic organization of BFTS biosynthetic gene clusters, their phylogenetic distribution in fungi, and cyclization properties of their metabolic products. KEY POINTS: • Genome mining of the first BFTS BGC harboring a glycosyltransferase. • Gene-deletion guided isolation revealed three novel 5-15 bicyclic sesterterpenoids. • Biosynthetic pathway of isolated sesterterpenoids was proposed.

Modification of human monocytes and macrophages by magnetic nanoparticles in vitro for cell-based delivery

The aim of the study was to develop a method for the modification of human monocytes/macrophages by iron oxide magnetic nanoparticles in vitro . Materials and methods . Iron oxide magnetic nanoparticles were obtained by a co-precipitation method and coated with a thin SiO 2 layer and polyethylene glycol 3000. Murine macrophage-like cell line RAW 264.7, primary human monocytes and macrophages were incubated with magnetic nanoparticles for 1–24 hours. The efficiency of cellular uptake of nanoparticles was measured using a ferrozine-based method and microcopy with Perls’ Prussian blue staining. The cell viability was tested by fluorescent flow cytometry using SYTOX Green. Results. Incubation of RAW264.7 cell, human monocytes and macrophages with magnetic nanoparticles at a concentration ˃ 5 µg/mL on a rotator for 1 hour at 37 °С provides the loading of nanoparticles into > 99% of cells. The magnetic nanoparticles have no adverse effect on the cell viability. The RAW264.7 cells modified with nanoparticles showed no change in migration activity. The efficiency of the nanoparticle uptake by macrophages was ˃50 pkg (Fe)/cell. Conclusion . According to the proposed method, macrophages loaded with magnetic nanoparticles have proved viable, they retain the ability to migrate, and therefore can be used as cell-based delivery systems for tumor diagnostic and therapy.

Systematic evaluation of potential pathogenicity of Salmonella Indiana

Salmonella Indiana has emerged in recent years as an important zoonotic pathogen, but its pathogenicity has not been fully elucidated. In this study, using in vivo and in vitro animal and cellular experimental model systems, we evaluated the pathogenicity of Salmonella Indiana (S. Indiana) compared with three other serotypes of Salmonella, S. Enteritidis, S. Typhimurium and S. Thompson. The animal experiments included observations of clinical symptoms, pathological changes and determination of median lethal dose in mice. The adhesion and invasiveness and intracellular proliferative capacity of Salmonella in vitro were measured with the murine macrophage-like cell line RAW264.7 cells and the human colon adenocarcinoma cell line Caco-2 cells. The results of animal experiments showed that S. Indiana, S. Enteritidis, S. Typhimurium and S. Thompson caused histopathological changes in most organs to varying degrees, primarily in the liver and intestine of mice. The gross lesions included white necrotic foci on the liver surface with different levels. The histopathological changes of monocyte/macrophage infiltration and coagulative necrosis were observed in the liver. Intestinal villi became short and were sloughed off, and lymphocyte infiltration was found in the submucosa. Compared with the other serotypes, the pathological changes caused by S. Indiana were slighter and had a relatively high median lethal dose in mice. The results of adhesion and invasion tests showed that the intracellular growth trend of most Salmonella strains was positively correlated with the number of pathogens adhering to and invading cells. Compared with the strains of the other three serotypes, most S. Indiana strains exhibited significantly lower adhesion and invasiveness to RAW264.7 and Caco-2 cells within 30 min. Most S. Indiana strains displayed twice to four times lower intracellular proliferation within 24 h in RAW264.7 cells. In conclusion, S. Indiana was pathogenic, but its pathogenicity was lower than that of S. Typhimurium and S. Enteritidis, and was similar to that of S. Thompson.

Vesicular stomatitis virus glycoprotein suppresses nuclear factor kappa-B- and mitogen-activated protein kinase-mediated pro-inflammatory responses dependent on sialic acids

Vesicular stomatitis (VS), characterized by vesicular lesions, produces significant economic losses in livestock industry. Infection by its causative agent, VS virus (VSV), has been previously shown to be mediated by the glycoprotein (G) during attachment, endocytosis and membrane fusion. In the current study, we revealed a novel role of VSV G protein in negative regulation of host cell pro-inflammatory responses. We determined that VSV G protein inhibited lipopolysaccharide (LPS)-induced pro-inflammatory responses as naïve VSV virions in murine peritoneal macrophage-like cell line RAW 264.7. Furthermore, we identified that VSV G protein suppressed nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK)-mediated pro-inflammatory pathways in a dose-dependent manner. Moreover, we demonstrated that α2-3-linked sialic acids on VSV G protein were involved in antagonizing NF-κB- and MAPK-mediated pro-inflammatory responses. All these results expand the knowledge of VSV pathogenesis and strengthen the importance of VSV G protein in host innate immunity, which support implications for the development of VSV-based vaccination and oncolysis.

Inhibitory effects of biseokeaniamide A against lipopolysaccharide-induced signal transduction

Lipopolysaccharides (LPS) are associated with various inflammatory diseases; therefore, the inhibition of LPS-induced nitric oxide (NO) production may have extensive therapeutic applications. We searched for inhibitors of NO production in the LPS-stimulated murine macrophage-like cell line RAW264.7 from MeOH extracts of marine organisms. The MeOH extract of the marine cyanobacterium Okeania sp., collected in Okinawa, Japan, showed inhibitory activity. Biseokeaniamide A was isolated from the MeOH extract by chromatographic separation. Biseokeaniamide A inhibited NO production without cytotoxicity. It reduced inducible nitric oxide synthase levels and suppressed the expression of IL-1β in LPS-stimulated RAW264.7 cells. Biseokeaniamide A did not inhibit IκBα degradation but inhibited IκBα expression. Thus, biseokeaniamide A, a naturally occurring lipopeptide, was identified as a selective inhibitor of LPS signal transduction.

Preventive Effects of Chrysanthemum coronarium L. Extract on Bone Metabolism In Vitro and In Vivo.

Osteoporosis is characterized by decreased bone mass and bone microarchitectural failure, leading to an enhanced risk of bone fractures. Chrysanthemum coronarium L. (CC) is a natural plant with powerful antioxidant activity. This study investigated the antiosteoporotic effects of CC extracts in in vitro cell cultures and in vivo bone loss animal models. CC stimulated osteoblast differentiation and mineralized bone formation by osteoblasts by increasing the expression of bone formation markers (alkaline phosphatase, osteoprotegerin, and osteoprotegerin/receptor activator nuclear factor-κB ligand ratio) in the murine preosteoblastic cell line MC3T3-E1. Additionally, CC was found to inhibit osteoclast differentiation by downregulating bone resorption markers (tartrate-resistant acid phosphatase, cathepsin K, dendritic cell-specific transmembrane protein, and calcitonin receptor) in the murine macrophage-like cell line RAW264.7. CC prevented ovariectomy-induced bone loss, preserved trabecular microarchitecture, and improved serum bone turnover markers in an osteoporotic mouse model. These findings suggest that CC extract may be considered as a natural therapeutic or preventive agent for osteoporotic bone loss.

Conservation of Ancient Genetic Pathways for Intracellular Persistence Among Animal Pathogenic Bordetellae.

Animal and human pathogens of the genus Bordetella are not commonly considered to be intracellular pathogens, although members of the closely related classical bordetellae are known to enter and persist within macrophages in vitro and have anecdotally been reported to be intracellular in clinical samples. B. bronchiseptica, the species closest to the ancestral lineage of the classical bordetellae, infects a wide range of mammals but is known to have an alternate life cycle, persisting, replicating and disseminating with amoeba. These observations give rise to the hypothesis that the ability for intracellular survival has an ancestral origin and is common among animal-pathogenic and environmental Bordetella species. Here we analyzed the survival of B. bronchiseptica and defined its transcriptional response to internalization by murine macrophage-like cell line RAW 264.7. Although the majority of the bacteria were killed and digested by the macrophages, a consistent fraction survived and persisted inside the phagocytes. Internalization prompted the activation of a prominent stress response characterized by upregulation of genes involved in DNA repair, oxidative stress response, pH homeostasis, chaperone functions, and activation of specific metabolic pathways. Cross species genome comparisons revealed that most of these upregulated genes are highly conserved among both the classical and non-classical Bordetella species. The diverse Bordetella species also shared the ability to survive inside RAW 264.7 cells, with the single exception being the bird pathogen B. avium, which has lost several of those genes. Knock-out mutations in genes expressed intracellularly resulted in decreased persistence inside the phagocytic cells, emphasizing the importance of these genes in this environment. These data show that the ability to persist inside macrophage-like RAW 264.7 cells is shared among nearly all Bordetella species, suggesting that resisting phagocytes may be an ancient mechanism that precedes speciation in the genus and may have facilitated the adaptation of Bordetella species from environmental bacteria to mammalian respiratory pathogens.

Eldecalcitol effects on osteoblastic differentiation and function in the presence or absence of osteoclastic bone resorption.

Eldecalcitol (ELD) is an active vitamin D3 analog, possesses anti-resorption properties and is an approved therapeutic drug for the treatment of osteoporosis in Japan. However, the effect of ELD on osteoblasts in a distinct cell microenvironment, including in the presence or absence of osteoclastic bone resorption, is undetermined. In the current study, the effect of bone resorption supernatant on the ELD-mediated regulation of viability, differentiation and receptor activator of ΝF-κB ligand/osteoprotegerin (RANKL/OPG) expression was assessed in MC3T3-E1 pre-osteoblast cells. The murine macrophage-like cell line RAW 264.7 was induced to differentiate into functional osteoblasts. Bone resorption supernatant was prepared by culturing osteoclast with a bovine cortical bone specimen. Mouse MC3T3-E1 cells were subsequently treated with ELD combined with differentiated osteoclast cell culture (OCS) or osteoclast bone resorption model supernatants. Cell counting kit-8, alkaline phosphatase (ALP) activity, reverse transcription-quantitative (RT-q) PCR and western blot analysis were used to assess cell viability, osteogenic activity and RANKL and OPG expression in MC3T3-E1 cells. The OCS and OCS + ELD treatment exhibited significantly increased MC3T3-E1 cell viability when compared with the control group. However, ELD, bone resorption culture supernatant (BRS) and ELD + BRS treatments significantly decreased MC3T3-E1 cell viability. The results of ALP activity analysis, RT-qPCR and western blot analysis demonstrated that ELD treatment and OCS decreased the osteogenic markers (ALP and RUNX2), however, BRS increased them. All treatments enhanced the expression of RANKL and RANKL/OPG ratio. The results of the current study revealed that ELD inhibits osteoblastic differentiation in vitro. However, in the presence of BRS, which mimics the local bone microenvironment in vivo, the net effect on osteogenesis was positive. Furthermore, osteoclasts and bone matrix-derived factors increased the RANKL/OPG ratio, thereby potentiating osteoclastic activity.

The cooperative induction of macrophage activation by fucoidan derived from Cladosiphon okamuranus and β-glucan derived from Saccharomyces cerevisiae

The present study investigated immune stimulatory effects of Cladosiphon okamuranus-derived fucoidan to activate murine macrophage-like cell line RAW264, and the functional relationship with zymosan, a Saccharomyces cerevisiae-derived β-glucan. The production of nitric oxide (NO) and tumor necrosis factor-α (TNF-α) in RAW264 cells were remarkably enhanced in the presence of 10 μg/mL fucoidan, and the stimulatory effects of fucoidan were maximally augmented in combinational treatment with 500 ng/mL zymosan, whereas any TLR ligands had no those effects. Confocal microscopic analyses suggested that fucoidan bound on plasma membrane, and it was estimated that some cell surface molecules acted as receptor for fucoidan because cytochalasin D, an inhibitor of phagocytosis, did not affect the immune enhancing activities, whereas methyl-β-cyclodextrin (MβCD), a general agent for disruption of lipid rafts, diminished that. Furthermore, it was revealed that the additive effects of zymosan on the immune activation with fucoidan was thought to be mediated by dectin-1 based on the results with dectin-1-knockdown RAW264 cells. All of results suggested that fucoidan and some kinds of β-glucan would cooperatively reinforce the activity of innate immune cells via interactive receptor crosstalk.

Phospholipase A2-Mediated preparation of phosphatidylcholine containing ricinoleic acid and its anti-inflammatory effect on murine macrophage-like RAW264.7 cells

Abstract Ricinoleic acid (RA) is a type of fatty acid found in castor oil and has been known to have anti-inflammatory effects. Phospholipids are useful functional compounds in food/medical fields due to their amphiphilic property and biocompatibility. The purpose of this study was to prepare phospholipid (PL) containing RA and to evaluate the anti-inflammatory activity of a prepared PL in vitro. Lyso-phosphatidylcholine (LPC) from egg yolk was subjected to phospholipase A2-mediated esterification for the preparation of phosphatidylcholine containing RA at sn-2 position (2-RA-PC). The prepared 2-RA-PC was then evaluated for its anti-inflammatory activity against the murine macrophage-like cell line RAW264.7 stimulated by lipopolysaccharide. Using glycerol as solvent and formamide as water mimic, 2-RA-PC was successfully prepared. Upon optimizing the molar ratio (RA/LPC), the amount of glycerol, and the reaction time, a maximum yield of 57.5 mol% was obtained. Analysis of fatty acid compositions of substrate LPC, RA, and synthesized PC suggested almost all RA was incorporated into sn-2 position of LPC. Down regulation of mRNA expression of pro-inflammatory cytokines, interleukin 6 and 1β was higher for 2-RA-PC than for RA or Soy-PC, which suggests that the anti-inflammatory effects of RA were improved following phosphatidylation. Our data suggest that 2-RA-PC is a potential lipid for use as an anti-inflammatory compound.

A Single Microorganism Epitope Attenuates the Development of Murine Autoimmune Arthritis: Regulation of Dendritic Cells via the Mannose Receptor.

A single epitope of Leishmania analog of the receptors for activated C kinase (LACK) from Leishmania major, the polypeptide LACK156–173, is recognized by Vβ4+/Vα8+ T cells, and activate these cells that drives the subsequent T helper (Th)2 response. This study was undertaken to investigate the therapeutic potential of the LACK156–173 epitope in murine autoimmune arthritis models. To explore the influence of the LACK156–173 epitope on murine collagen antibody-induced arthritis, as well as its immunological mechanism, we vaccinated or treated mice with a LACK156–173 epitope expression plasmid or polypeptide. The effect of LACK156–173 epitope was then evaluated by clinical scores, histopathology, and quantitative real-time polymerase chain reaction (qRT-PCR) analysis. Using flow cytometry, we measured the subsets and maturity of CD11c+ dendritic cells (DCs), as well as T cell polarization, in co-culture experiments. We also measured cytokine gene expression and production. The murine macrophage-like cell line RAW264.7 was used to identify the receptor for the epitope. Vaccination or treatment of the mice with the LACK156–173 epitope expression plasmid or polypeptide ameliorated the severity of arthritis. qRT-PCR analysis revealed that the LACK156–173 epitope improved the balance of effector T cells in synovial tissue compared to that in untreated arthritis controls. Toll-like receptor (TLR) 4 expression was diminished by LACK156–173. The epitope also influenced T cell polarization by regulating the differentiation, maturation, and functions of CD11c+ DCs and upregulating Jagged1 ligand expression. Blocking the mannose receptor (MR) significantly attenuated LACK156–173 epitope-induced macrophage activation. Our data indicate that vaccination or treatment with a single microorganism epitope, LACK156–173, is a highly efficient therapy for murine autoimmune arthritis. The therapeutic effects are mediated by the regulation of the differentiation, maturation, and functions of DCs via MR, resulting in the upregulation of Jagged1 expression and Th2 cell polarization. Our results demonstrate the therapeutic potential of the LACK156–173 epitope in rheumatoid arthritis.

Imidazolines increase the levels of the autophagosomal marker LC3-II in macrophage-like RAW264.7 cells

This study evaluated whether imidazolines can induce autophagy in the murine macrophage-like cell line RAW264.7. Idazoxan increased the content of LC3-II, an autophagosomal marker, in RAW264.7 cells. To determine whether this effect was due to the induction of its synthesis or inhibition of its degradation, idazoxan treatment was performed in the presence of bafilomycin A1, which blocks autophagosome-lysosome fusion, as well as Pepstatin A and E-64d, both of which block protein degradation in autolysosomes. An increased content of LC3-II was observed in the presence of bafilomycin A1 as well as the protease inhibitors. Furthermore, an increased number of autophagosomes was observed following idazoxan treatment using an autophagosome-specific dye. This indicated that idazoxan induced autophagy. Other imidazolines, such as efaroxan, clonidine, and 2-(2-benzofuranyl)-2-imidazoline, also increased the LC3-II content in RAW264.7 cells in the presence of bafilomycin A1. Taken together, these results indicate that some imidazolines, including idazoxan, can induce autophagy in RAW264.7 cells.

Evaluation of cell activation promoted by tantalum and tantalum oxide coatings deposited by reactive DC magnetron sputtering

Previous studies have shown both Ta and TaO to be bioactive, rapidly forming a strongly-bonded surface-adherent layer of bone-like hydroxyapatite (HAp) when immersed in simulated body fluid (SBF). Consequently, Ta and TaO coatings are promising for the surface-modification of Ti or stainless steel endodontic endosseous implants, being conducive to a reduction in the risk of developing post-operatory infection and/or peri-implantitis disease. That said, few studies have investigated the effect of Ta or TaO coatings on such phenomena as cell activation, adhesion, and proliferation.To that effect, Ta, and TaO films were deposited onto type 316L stainless steel (SS 316L) substrates by reactive DC magnetron sputtering, after which their biological response was evaluated following co-incubation with the murine macrophage-like cell line RAW 264.7. Cell morphology after adhesion was observed by SEM, whereas cell viability and proliferation were evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. Lastly, inflammatory response was assessed by quantification of the cytokines interleukin-6 (IL-6) and interleukin-10 (IL-10).In terms of phase composition, Ta showed a mixture of the α-Ta and β-Ta phases, whereas TaO showed a nanocrystalline structure. Moreover, a decrease in average roughness (Ra) from 21nm to 7nm was observed between Ta and TaO, accompanied by a decrease in water contact angle (θW) from 106° to 83°.In vitro studies showed that cells exhibited significantly better adhesion to Ta, in comparison with both TaO and SS 316L. Furthermore, both Ta and TaO were shown to be non-cytotoxic, with Ta outperforming TaO in terms of relative cell viability, both at 24h and 48h. Lastly, both Ta and TaO showed vastly inferior IL-6 and IL-10 levels to those obtained for cells treated with bacterial lipopolysaccharides (LPS)—prompting the conclusion that the coatings do not in any way induce an inflammatory response from macrophage cells.

Modulation of the anti-inflammatory effects of phosphatidylserine-containing liposomes by PEGylation.

Inhibiting liposome uptake by macrophages using polyethylene glycol (PEG) surface modifications is a widely used approach for extending the half-life of liposomes circulating in the blood. However, the biological effects of PEGylated liposomes on macrophages have not yet been thoroughly investigated. The purpose of this study was to examine the effects of PEGylated phosphatidylserine-containing liposomes (PEG-PSLs) on the expression of two inflammation-associated cytokines, tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β), in the murine macrophage-like cell line RAW 264.7. Previous studies have demonstrated that PSLs inhibit TNF-α secretion and enhance TGF-β synthesis in macrophages by mimicking apoptotic cells. We found that PEGylation differentially affected the TNF-α and TGF-β levels. The PSL-mediated inhibitory effect on TNF-α secretion was enhanced by PEGylation, and PEG-PSLs decreased TGF-β levels compared with non-PEGylated PSLs. Fluorescence-activated cell sorting analysis demonstrated that 1% PEGylation disturbed the incorporation of PSLs into macrophages. The interference of uptake is thought to extend the binding interaction between PS to PS receptors for PSL-mediated inhibition of TNF-α expression. Together, these findings indicate that PEG-PSLs can prevent TNF-α secretion without increasing TGF-β levels in macrophages, and they support the potential clinical use of PEG-PSLs as anti-inflammatory agents with a relatively low potential to induce tissue fibrosis. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1479-1486, 2017.

Site-specific quantification of lysine acetylation in the N-terminal tail of histone H4 using a double-labelling, targeted UHPLC MS/MS approach.

We developed a targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the site-specific quantification of lysine acetylation in the N-terminal region of histone H4 by combining chemical derivatization at the protein and peptide levels with digestion using chymotrypsin and trypsin. Unmodified ε-amino groups were first modified with propionic acid anhydride and the derivatized protein digested with trypsin and chymotrypsin. The newly formed peptide N-termini were subjected to a second derivatization step with d6- (heavy) or d0- (light) acetic acid anhydride. Samples were mixed at different ratios and peptides monitored by multiple reaction monitoring (MRM) LC-MS/MS. The method was validated in terms of linearity (R2 ≥ 0.94), precision (RSD ≤ 10 %), and accuracy (≤27 %) and used to assess the effect of the histone deacetylase (HDAC) inhibitors SAHA and MS-275 in the murine macrophage-like cell line RAW 264.7. SAHA and MS-275 showed site-specific effects on the acetylation levels of K5 and K8 with the K5(Ac)–K8 and K5–K8(Ac) peptides increasing 2.5-fold and 5-fold upon treatment with SAHA and MS-275, respectively. Assessing lysine acetylation in a site-specific manner is important for gaining a better understanding of the effects of HDAC inhibitors and for clarifying disease mechanisms where lysine acetylation plays a role.Electronic supplementary materialThe online version of this article (doi:10.1007/s00216-016-9431-1) contains supplementary material, which is available to authorized users.

Coumarins from the Twigs of Juglans regia and Their Nitric Oxide Inhibitory Activities

In our investigation of in vitro anti-allergic screening of medicinal herbal extracts, the chloroform extract of the twigs of Juglans regia L. was observed to show inhibitory activity on nitric oxide (NO) production in a lipopolysaccharide (LPS) and recombinant mouse interferon-γ activated murine macrophage-like cell line RAW 264.7. Fractionation of the active extract led to the isolation of one new coumarin, juglanslactone (1), with four known compounds, isoscopoletin (2), osthol (3), psoralene (4), and ayapanin (5). The structures and configurations were elucidated by spectroscopic methods.