Extracellular Protein Concentration Research Articles

Combined use of polymeric ferric sulfate and chitosan as a conditioning aid for enhanced digested sludge dewatering

ABSTRACTIn this study, the effects of polymeric ferric sulfate (PFS) and chitosan (CTS) on the dewatering characteristics of the digested activated sludge (e.g. filtrate turbidity, specific resistance of filtration (SRF), and cake moisture content) were investigated. The combined conditioning of PFS and CTS improved the settleability of the digested sludge more effectively than when using of PFS alone. The SRF value of the digested sludge decreased to 2.08 × 1012 m/kg after conditioning with 50 mg/g PFS and 10 mg/g CTS. Furthermore, a minimum moisture content of 68% was obtained when 40 mg/g PFS and 10 mg/g CTS were used to condition the digested sludge. At a fixed dose of PFS, the concentrations of extracellular polymeric substances, including polysaccharides (C/C0 = 2.1), proteins (C/C0 = 2.7), and deoxyribonucleic acids (C/C0 = 7.8) in the supernatant were increased considerably with an increase in CTS dose (0–10 mg/g). Phosphorus could be recovered efficiently as a result of charge neutralization and the adsorption-bridging effects of CTS, which promote the release of phosphorus from the digested activated sludge. The concentrations of heavy metals in the digested sludge conditioned with 40 mg/g PFS and 10 mg/g CTS satisfied the agricultural safety requirements. These results indicate that conditioning the digested sludge with combinations of PFS and CTS improves its dewatering performance and enables its direct use as a fertilizer.

Correlation among lipid parameters, pulse wave velocity and central blood pressure in young Korean population

ABSTRACTBackground: Central blood pressure is closely related to the important cardiovascular intermediate end points, such as vascular hypertrophy and extent of carotid atherosclerosis. Therefore it is prudent to study correlation among central aortic blood pressure, body composition, lipid profiles, and pulse wave velocity in population-based study. Consequently, we investigate the correlation between central aortic blood pressure and other risk parameters of hypertension such as body composition and lipid profile. Methods: We recruited 20 young participants diagnosed with hypertension as well as 30 without hypertension. The study used an X-SCAN PLUS 950 machine for measurement of overall body composition. Measurements of central blood pressure and carotid–femoral pulse wave velocity were carried out using SphygmoCor XCEL. Results: The hypertensive participants had significantly higher total weight without fat, body moisture mass, muscle mass, body mass index, basal metabolic rate, intracellular and extracellular water contents, protein and mineral contents along with brachial and central aortic blood pressures. In both hypertensive and non-hypertensive participants, central aortic diastolic blood pressure were significantly related to the lipid parameters. Conclusion: Overall, the correlations between central blood pressure, pulse wave velocity, and lipid profile in hypertensive and non-hypertensive participants were substantial.

Quercetin reduces adhesion and inhibits biofilm development by Listeria monocytogenes by reducing the amount of extracellular proteins

The aim of the present study was to investigate the inhibitory mechanisms of quercetin against L. monocytogenes biofilm formation, by affecting secretion of polymeric substances (EPS) and spatio-temporal organization. The minimum concentration of quercetin inhibiting the establishment of bacterial biofilm was determined to be 0.8 mM; therefore, a lower concentration of the flavonoid (0.2 mM) was used in order to investigate its effect on cell attachment and EPS production on stainless steel and the spatio-temporal organization on glass, while avoiding bias of loss of cellular viability. In applying this concentration, reductions of 1.32 and 1.94 Log10 CFU/cm2 of initial adhesion and maximum cell density on stainless steel were observed on the test surfaces at 2 h (initial adhesion) and 24 h (maximum cell density), respectively. EPS on mature biofilms (24 h) was mainly composed by proteins (97.83%), followed by polysaccharides (2.03%) and DNA (0.14%). In addition, quercetin reduced total extracellular protein content by 41% compared with control; while, DNA and polysaccharide contents in biofilms were not affected. Also, relative to control, quercetin impaired surface colonization, early stages of biofilm formation and the development of a more complex architecture during its formation. This proved that quercetin inhibited the formation of L. monocytogenes biofilms by reducing initial attachment, the amount of extracellular proteins found in the EPS matrix and the overall spatio-temporal organization of L. monocytogenes.

Virulence Factors in Candida albicans and Streptococcus mutans Biofilms Mediated by Farnesol.

The aim of this study was to evaluate the effect of farnesol on the production of acids and hydrolytic enzymes by biofilms of Streptococcus mutans and Candida albicans. The present study also evaluated the time-kill curve and the effect of farnesol on matrix composition and structure of single-species and dual-species biofilms. Farnesol, at subinhibitory concentrations, showed a significant reduction in S. mutans biofilm acid production, but did not alter C. albicans hydrolytic enzyme production. The number of cultivable cells of both microorganisms was significantly reduced after 8h of contact with farnesol. Extracellular matrix protein content was reduced for biofilms formed in the presence of farnesol. In addition, confocal laser scanning and scanning electron microscopy displayed structural alterations in all biofilms treated with farnesol, which included reduction in viable cells and extracellular matrix. In conclusion, farnesol showed favorable properties controlling some virulence factors of S. mutans and C. albicans biofilms. These findings should stimulate further studies using this quorum-sensing molecule, combined with other drugs, to prevent or treat biofilm-associated oral diseases.

Advanced glycation end products as a source of artifacts in immunoenzymatic methods

The most abundant proteins in the arteries are those of extracellular matrix, ie. collagen and elastin. Due to their long half-lifes these proteins have an increased chance to undergo glycation. The aim of this study was to determine relationship between the content of the main extracellular matrix proteins and the advanced glycation end products (AGEs) in arteries. In this study 103 fragments of aorta were analyzed by ELISA and immunobloting for the content of collagens type I, III and IV and elastin and the content of advanced glycation end-products (AGE). A negative correlation between the content of collagens type III and IV and AGE (r = −0,258, p = 0,0122, and a weak negative correlation between collagen type III and age of the sample donor (r = 0,218, p = 0,0262) were demonstrated. This result comes as a surprise and it contradicts an intuitive assumption that with more glycation substrate, i.e. matrix proteins, more AGE products are expected. We have concluded that the results of the ELISA tests must have been influenced by the glycation. As a consequence, either modified protein molecules were not being recognized by the antibodies, or the glycation, and formation of crosslinks have blocked access of the antibodies to the antigen. It will conceal the effect of the linear dependence between the result (absorbance/densitometry) from the quantity of protein to which the antibody is directed.

Role of cardiac T1 mapping and extracellular volume in the assessment of myocardial infarction.

Although late gadolinium enhancement on cardiac magnetic resonance imaging remains the reference standard for scar assessment, it does not provide quantitative information about the extent of pathophysiological changes within the scar tissue. T1 mapping and extracellular volume (ECV) mapping are steadily becoming diagnostic and prognostically useful tests for in vivo myocardial histology, influencing clinical decision-making. Quantitative native T1 maps (acquired without a contrast agent) represent the longitudinal relaxation time within the myocardium and changes with myocardial extracellular water (edema, focal, or diffuse fibrosis), fat, iron, and amyloid protein content. Post-contrast ECV maps estimate the size of the extracellular space and have sensitivity in the identification of interstitial disease. Both pre- and post-contrast T1 mapping are emerging as comprehensive tools for the assessment of numerous conditions including ischemic scarring that occurs post myocardial infarction (MI). This review outlines the current evidence and potential future role of T1 mapping in MI. We conclude by highlighting some of the remaining challenges such as quality control, standardization of image acquisition for clinical practice, and automated methods for quantifying infarct size, area at risk, and myocardial salvage post MI.

Enhancing Cellulase and Hemicellulase Production in Trichoderma orientalis EU7-22 via Knockout of the creA.

The role of the transcription factor creA-mediating carbon catabolite repression in Trichoderma orientalis EU7-22 was investigated for cellulase and hemicellulase production. The binary vector pUR5750G/creA::hph was constructed to knock out creA by homologous integration, generating the ΔcreA mutant Trichoderma orientalis CF1D. For strain CF1D, the filter paper activities (FPA), endoglucanase activities (CMC), cellobiohydrolase activity(CBH), β-glucosidase activity (BG), xylanase activity (XYN), and extracellular protein concentration were 1.45-, 1.15-, 1.71-, 2.51-, 2.72, and 1.95-fold higher in inducing medium and were 6.41-, 7.50-, 10.27-, 11.79-, 9.25-, and 3.77-fold higher in glucose repressing medium, respectively, than those in the parent strain after 4days. SDS-PAGE demonstrated that the extracellular proteins were largely secreted in the mutant CF1D. Quantitative reverse-transcription polymerase chain reaction indicated that the expressions of cbh1, cbh2, eg1, eg2, bgl1, xyn1, and xyn2 were significantly increasing for the mutant CF1D not only in the inducing medium but also in the repressing medium. Those results indicated that creA was a valid target gene in strain engineering for improved enzyme production in T. orientalis.

Evolution and functional analysis of extracellular polymeric substances during the granulation of aerobic sludge used to treat p-chloroaniline wastewater

Extracellular polymeric substances (EPS) are major high-molecular-weight secretions from microorganisms, binding with cells to form a vast net-like structure for protecting cells against external stress. In this study, the level and function of EPS during the granulation of aerobic sludge used to treat p-chloroaniline (p-ClA) wastewater were investigated. The content of extracellular proteins (PN) increased relative to the exopolysaccharides (PS) content during the sludge granulation (Stage I), implying that PN contributed significantly to the formation of aerobic granular sludge (AGS). Under the condition of high p-ClA shock loading (Stage II), the PS content increased from 122.7±22.0mgg−1VSS to 482.6±5.4mgg−1VSS, which might be a regulating mechanism of AGS to address high p-ClA loading. The results of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that PN bands increased with the development of sludge granulation, particularly the proteins with molecular weight located at 44.3–97.2kDa. Fourier transform infrared (FTIR) spectra of inoculated activated sludge and matured granular sludge indicated that microorganisms appeared to aggregate in the presence of tyrosine protein, aspartic acid protein and proteins with secondary structures including 3-turn helix and β-sheets. Five types of proteins were identified by two-dimensional electrophoresis (2-DE), and these proteins were related to the granulation of aerobic sludge and EPS secretion. Furthermore, the analysis of sludge microbial community revealed that the enrichment of Zoogloea spp. and Thauera spp. as p-ClA degrading and EPS secreting microbes was conducive to the formation of granular sludge and degradation of p-ClA.

Quantifying time-varying cellular secretions with local linear models.

Extracellular protein concentrations and gradients initiate a wide range of cellular responses, such as cell motility, growth, proliferation and death. Understanding inter-cellular communication requires spatio-temporal knowledge of these secreted factors and their causal relationship with cell phenotype. Techniques which can detect cellular secretions in real time are becoming more common but generalizable data analysis methodologies which can quantify concentration from these measurements are still lacking. Here we introduce a probabilistic approach in which local-linear models and the law of mass action are applied to obtain time-varying secreted concentrations from affinity-based biosensor data. We first highlight the general features of this approach using simulated data which contains both static and time-varying concentration profiles. Next we apply the technique to determine concentration of secreted antibodies from 9E10 hybridoma cells as detected using nanoplasmonic biosensors. A broad range of time-dependent concentrations was observed: from steady-state secretions of 230 pM near the cell surface to large transients which reached as high as 56 nM over several minutes and then dissipated.

Biodegradation of poly(lactic acid)/chitosan stratified composites in presence of the Phanerochaete chrysosporium fungus

Phanerochaete chrysosporium white rot fungus was tested for its ability to biodegrade poly(lactic acid)-based materials gamma irradiated or nitrogen plasma activated and chitosan-surface grafted. Biochemical parameters (superoxide dismutase, catalase, malondialdehyde) of the fungus were monitored in respect with soluble protein for 14 days of inoculation. The specific activities of both enzymes (catalase and superoxide dismutase) increased and reached a maximum after 14 days of incubation. Fungal extracellular protein concentration increases by gamma irradiation or plasma treatment of PLA, while a slightly decrease is determined by chitosan grafting. The fungus attached itself to polymer film surfaces, continued growing, and slowly degraded them. The degradation was monitored by infrared spectroscopy (FTIR), gel permeation chromatography (GPC), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Notable structural modifications appear by fungal biodegradation of PLA/chitosan-based samples showing beginning of the hydrolytic/fungal action process of degradation. Fungal biodegradation increases the crystallinity (FTIR determined) of all samples, indicating that the degradation occurs mainly in amorphous regions. A significant decrease of the average molecular weight of the PLA-based samples is noticed after fungus action. Surface physical degradation observed by SEM and AFM was highlighted by an increase of the roughness of the polymeric surfaces.

Oviduct extracellular vesicles protein content and their role during oviduct-embryo cross-talk.

Successful pregnancy requires an appropriate communication between the mother and the embryo. Recently, exosomes and microvesicles, both membrane-bound extracellular vesicles (EVs) present in the oviduct fluid have been proposed as key modulators of this unique cross-talk. However, little is known about their content and their role during oviduct-embryo dialog. Given the known differences in secretions by in vivo and in vitro oviduct epithelial cells (OEC), we aimed at deciphering the oviduct EVs protein content from both sources. Moreover, we analyzed their functional effect on embryo development. Our study demonstrated for the first time the substantial differences between in vivo and in vitro oviduct EVs secretion/content. Mass spectrometry analysis identified 319 proteins in EVs, from which 186 were differentially expressed when in vivo and in vitro EVs were compared (P < 0.01). Interestingly, 97 were exclusively expressed in in vivo EVs, 47 were present only in in vitro and 175 were common. Functional analysis revealed key proteins involved in sperm-oocyte binding, fertilization and embryo development, some of them lacking in in vitro EVs. Moreover, we showed that in vitro-produced embryos were able to internalize in vivo EVs during culture with a functional effect in the embryo development. In vivo EVs increased blastocyst rate, extended embryo survival over time and improved embryo quality. Our study provides the first characterization of oviduct EVs, increasing our understanding of the role of oviduct EVs as modulators of gamete/embryo-oviduct interactions. Moreover, our results point them as promising tools to improve embryo development and survival under in vitro conditions.

Enzymatic Degradation of Aromatic and Aliphatic Polyesters by P. pastoris Expressed Cutinase 1 from Thermobifida cellulosilytica.

To study hydrolysis of aromatic and aliphatic polyesters cutinase 1 from Thermobifida cellulosilytica (Thc_Cut1) was expressed in P. pastoris. No significant differences between the expression of native Thc_Cut1 and of two glycosylation site knock out mutants (Thc_Cut1_koAsn and Thc_Cut1_koST) concerning the total extracellular protein concentration and volumetric activity were observed. Hydrolysis of poly(ethylene terephthalate) (PET) was shown for all three enzymes based on quantification of released products by HPLC and similar concentrations of released terephthalic acid (TPA) and mono(2-hydroxyethyl) terephthalate (MHET) were detected for all enzymes. Both tested aliphatic polyesters poly(butylene succinate) (PBS) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were hydrolyzed by Thc_Cut1 and Thc_Cut1_koST, although PBS was hydrolyzed to significantly higher extent than PHBV. These findings were also confirmed via quartz crystal microbalance (QCM) analysis; for PHBV only a small mass change was observed while the mass of PBS thin films decreased by 93% upon enzymatic hydrolysis with Thc_Cut1. Although both enzymes led to similar concentrations of released products upon hydrolysis of PET and PHBV, Thc_Cut1_koST was found to be significantly more active on PBS than the native Thc_Cut1. Hydrolysis of PBS films by Thc_Cut1 and Thc_Cut1_koST was followed by weight loss and scanning electron microscopy (SEM). Within 96 h of hydrolysis up to 92 and 41% of weight loss were detected with Thc_Cut1_koST and Thc_Cut1, respectively. Furthermore, SEM characterization of PBS films clearly showed that enzyme tretment resulted in morphological changes of the film surface.

Activity of the endophytic fungi Phlebia sp. and Paecilomyces formosus in decolourisation and the reduction of reactive dyes' cytotoxicity in fish erythrocytes.

The current study investigates the potential for discolouration and degradation of Reactive Blue 19 and Reactive Black 5 textile dyes by endophytic fungi Phlebia sp. and Paecilomyces formosus as well as the potential cytotoxicity of products or by-products generated by the treatments in fish erythrocytes. It was observed at 30days that both endophytes showed biodegradation activity with 0.1gmL-1 of dyes. P. formosus showed highest extracellular and intracellular protein content levels after the 15th day, and Phlebia sp. stands out for production of extracellular laccase, indicating that this enzyme may be associated with the decolouration capacity. The dyes showed toxic effects in fishes at 0.01gmL-1 concentration, resulting in the appearance of micronuclei in erythrocyte cells. When degraded dyes treated by endophytes were tested, the frequency of micronuclei reduced approximately 20%, indicating the effectiveness of these endophytic in the treatment of textile dyes with less environmental impact, thus indicating a potential for application of these fungi in bioremediation process.

Exogenous addition of cellular extract N-acyl-homoserine-lactones accelerated the granulation of autotrophic nitrifying sludge

Granulation of nitrifying bacteria could achieve high biomass concentration in treatment system and result in the higher rate of ammonia oxidation and removal even under short hydraulic retention time. However, it is a major challenge to achieve granular sludge in nitrification stage. The addition of chemically synthetic N-acyl-homoserine lactones (AHLs) into bioreactors could enhance the attached-growth of nitrifying microorganisms from sludge and followed by sludge granulation, but it is not suitable for full-scale operations due to the high cost. In this study, cellular extract of AHLs from nitrifying granular sludge (NGS) was added into the nitrifying activated sludge to investigate the effect of the NGS cellular extract on the adhesion and granulation of autotrophic nitrifying sludge. The results indicated that NGS contained AHL molecules and the exogenous addition of the NGS cellular extract could improve the cell adhesion and aggregation. Moreover, addition of the NGS cellular extract increased the microbial activity, the concentration of extracellular proteins (PN) and the biomass of autotrophic nitrifying bacteria, which eventually contributed to the nitrifying sludge granulation. Addition of exogenous cellular-based AHL from NGS in the early start-up stage is a potentially promising approach for full-scale application of nitrifying sludge granulation with reduced cost.

An orally active geranyl acetophenone attenuates airway remodeling in a murine model of chronic asthma

2,4,6-Trihydroxy-3-geranyl acetophenone (tHGA) is a synthetic compound that is naturally found in Melicope ptelefolia. We had previously demonstrated that parenteral administration of tHGA reduces pulmonary inflammation in OVA-sensitized mice. In this study, we evaluated the effect of orally administered tHGA upon airway remodeling in a murine model of chronic asthma. Female BALB/C mice were sensitized intraperitoneally with ovalbumin (OVA) on day 0, 7 and 14, followed by aerosolized 1% OVA 3 times per week for 6 weeks. Control groups were sensitized with saline. OVA sensitized animals were either treated orally with vehicle (saline with 1% DMSO and Tween 80), tHGA (80, 40, 20mg/kg) or zileuton (30mg/kg) 1h prior to each aerosolized OVA sensitization. On day 61, mice underwent methacholine challenge to determine airway hyperresponsiveness prior to collection of bronchoalveolar lavage (BAL) fluid and lung samples. BAL fluid inflammatory cell counts and cytokine concentrations were evaluated while histological analysis and extracellular matrix protein concentrations were determined on collected lung samples. Oral tHGA treatment attenuated airway hyperresponsiveness and inhibited airway remodeling in a dose-dependent fashion. tHGA's effect on airway remodeling could be attributed to the reduction of inflammatory cell infiltration and decreased expression of cytokines associated with airway remodeling. Oral administration of tHGA attenuates airway hyperresponsiveness and remodeling in OVA-induced BALB/c mice. tHGA is an interesting compound that should be evaluated further for its possible role as an alternative non-steroidal pharmacological approach in the management of asthma.

Interleukin-26 Production in Human Primary Bronchial Epithelial Cells in Response to Viral Stimulation: Modulation by Th17 cytokines

Interleukin (IL)-26 is abundant in human airways and this cytokine is involved in the local immune response to a bacterial stimulus in vivo. Specifically, local exposure to the toll-like receptor (TLR) 4 agonist endotoxin does increase IL-26 in human airways and this cytokine potentiates chemotactic responses in human neutrophils. In addition to T-helper (Th) 17 cells, alveolar macrophages can produce IL-26, but it remains unknown whether this cytokine can also be produced in the airway mucosa per se in response to a viral stimulus. Here, we evaluated whether this is the case using primary bronchial epithelial cells from the airway epithelium in vitro and explored the signaling mechanisms involved, including the modulatory effects of additional Th17 cytokines. Finally, we assessed IL-26 and its archetype signaling responses in healthy human airways in vivo. We found increased transcription and release of IL-26 protein after stimulation with the viral-related double stranded (ds) RNA polyinosinic-polycytidylic acid (poly-IC) and showed that this IL-26 release involved mitogen-activated protein (MAP) kinases and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). The release of IL-26 in response to a viral stimulus was modulated by additional Th17 cytokines. Moreover, there was transcription of IL26 mRNA and expression of the protein in epithelial cells of bronchial brush and tissue biopsies respectively after harvest in vivo. In addition, the extracellular IL-26 protein concentrations in bronchoalveolar lavage (BAL) samples did correlate with increased epithelial cell transcription of an archetype intracellular signaling molecule downstream of the IL-26-receptor complex, STAT1, in the bronchial brush biopsies. Thus, our study suggests that viral stimulation causes the production of IL-26 in lining epithelial cells of human airways, structural cells that constitute a critical immune barrier and that this production is modulated by Th17 cytokines.

Nonlinear dynamical model for a cancer cell death

The nonlinear biochemical processes and feedback play a crucial role in the physiology of living organism; they are powerful tools that allow us to understand the complex biochemical processes and their dynamics. Nonlinear biochemistry has been used to explain the mechanism of regulation of thyroid hormone, the Krebs cycle and blood pH. Another example of such tools is the process of cell death in various forms. There are mathematical models, which show the dynamics of protein synthesis in the cell; such models demonstrate the nonlinearity of the mechanism showing how the concentration of intracellular and extracellular proteins varies depending on metabolic needs of the cell. These models can be used to describe the dynamics of different biochemical mechanisms involved in cell death. In particular, in this paper we employ nonlinear dynamics to model in a closed system two cells, one normal and one cancerous.

470 - Alteration of Circulating Extracellular Vesicle Protein Contents Is a Fingerprint of Chemotherapy-Induced Tissue Damage

Extracellular vesicles (EVs) including exosomes, microvesicles and apoptotic bodies are released from most cell types; especially under cellular stress conditions, including oxidative stress. The high abundance of EVs in biological fluids and their unique stability make them a potential biomarker for many diseases. It is well recognized that in addition to ionizing radiation, nearly 50% of current FDA approved chemotherapeutic drugs cause reactive oxygen species (ROS) in target tissues. However, the molecular cargo contained within EVs that are released from chemotherapy-treated cells, as well as their contribution to tissue injury are unknown. Here we report that EV contents mirror pathological conditions of the tissues affected by chemotherapy. In mice, systemic injection of doxorubicin (DOX), a potent and known ROS generator chemotherapeutic agent used for aggressive cancer, caused approximately two-fold increase in circulating EVs (DOX_EVs) compared to the saline treated controls (SAL_EVs). In mouse (n=4) and human serum (n=24), EVs exhibits a significantly higher level of 4-hydroxynonenal adducted proteins post chemotherapy (P

Aspergillus fumigatus responds to natural killer (NK) cells with upregulation of stress related genes and inhibits the immunoregulatory function of NK cells.

Natural Killer (NK) cells are active against Aspergillus fumigatus, which in turn is able to impair the host defense. Unfortunately, little is known on the mutual interaction of NK cells and A. fumigatus. We coincubated human NK cells with A. fumigatus hyphae and assessed the gene expression and protein concentration of selected molecules. We found that A. fumigatus up-regulates the gene expression of pro-inflammatory molecules in NK cells, but inhibited the release of these molecules resulting in intracellular accumulation and limited extracellular availability. A. fumigatus down-regulatedmRNA levels of perforin in NK cells, but increased its intra- and extracellular protein concentration. The gene expression of stress related molecules of A. fumigatus such as heat shock protein hsp90 was up-regulated by human NK cells. Our data characterize for the first time the immunosuppressive effect of A. fumigatus on NK cells and may help to develop new therapeutic antifungal strategies.

New Insights into the Pro-Inflammatory Activities of Ang1 on Neutrophils: Induction of MIP-1β Synthesis and Release.

We reported the expression of angiopoietin Tie2 receptor on human neutrophils and the capacity of angiopoietins (Ang1 and Ang2) to induce pro-inflammatory activities, such as platelet-activating factor synthesis, β2-integrin activation and neutrophil migration. Recently, we observed differential effects between both angiopoietins, namely, the capacity of Ang1, but not Ang2, to promote rapid interleukin-8 synthesis and release, as well as neutrophil viability. Herein, we addressed whether Ang1 and/or Ang2 could modulate the synthesis and release of macrophage inflammatory protein-1β (MIP-1β) by neutrophils. Neutrophils were isolated from blood of healthy volunteers; intracellular and extracellular MIP-1β protein concentrations were assessed by ELISA. After 24 hours, the basal intracellular and extracellular MIP-1β protein concentrations were ≈500 and 100 pg/106 neutrophils, respectively. Treatment with Ang1 (10 nM) increased neutrophil intracellular and extracellular MIP-1β concentrations by 310 and 388% respectively. Pretreatment with PI3K (LY294002), p38 MAPK (SB203580) and MEK (U0126) inhibitors completely inhibited Ang1-mediated increase of MIP-1β intracellular and extracellular protein levels. Pretreatment with NF-κB complex inhibitors, namely Bay11-7085 and IKK inhibitor VII or with a transcription inhibitor (actinomycin D) and protein synthesis inhibitor (cycloheximide), did also abrogate Ang1-mediated increase of MIP-1β intracellular and extracellular protein levels. We validated by RT-qPCR analyses the effect of Ang1 on the induction of MIP-1β mRNA levels. Our study is the first one to report Ang1 capacity to induce MIP-1β gene expression, protein synthesis and release from neutrophils, and that these effects are mediated by PI3K, p38 MAPK and MEK activation and downstream NF-κB activation.