Marina C. Oliveira

Oral administration of bovine milk derived extracellular vesicles attenuates arthritis in two mouse models.

SCOPE This study shows the effect of bovine milk derived extracellular vesicles (BMEVs) on spontaneous polyarthritis in IL-1Ra-deficient mice and collagen-induced arthritis. METHODS AND RESULTS BMEVs were isolated from semi-skimmed milk by ultracentrifugation and the particle size was around 100 nm by dynamic light scattering and electron microscopy. BMEVs expressed exosome marker CD63, immunoregulatory microRNAs (miR-30a, -223, -92a), and milk-specific beta-casein and beta-lactoglobulin mRNA. In vitro, PKH-67-labeled BMEVs were taken up by RAW264.7, splenocytes, and intestinal cells as determined by flow cytometry and confocal microscopy. IL-1Ra(-/-) mice received BMEVs by daily oral gavage starting at wk 5 till 15 after birth and collagen-induced arthritis mice via their drinking water starting 1 wk before immunization till day 40. Macroscopically, BMEV treatment delayed the onset of arthritis and histology showed diminished cartilage pathology and bone marrow inflammation in both models. BMEV treatment also reduced the serum levels of MCP-1 and IL-6 and their production by splenic cells. BMEV treatment diminished the anticollagen IgG2a levels, which was accompanied by reduced splenic Th1 (Tbet) and Th17 (RORγT) mRNA. CONCLUSION This is the first report that oral delivery of BMEVs ameliorates experimental arthritis and this warrants further research to determine whether this beneficial effect can be seen in rheumatoid arthritis patients.

Acute and sustained inflammation and metabolic dysfunction induced by high refined carbohydrate-containing diet in mice.

The effects of high‐refined carbohydrate‐containing diet (HC) on inflammatory parameters and metabolic disarrangement of adipose tissue are poorly understood. The aim of this study was to evaluate the timing and progression of metabolic and inflammatory dysfunction induced by HC diet in mice.

Modulation of adipose tissue inflammation by FOXP3+ Treg cells, IL-10, and TGF-β in metabolically healthy class III obese individuals

OBJECTIVE The objective of this study was to compare the profiles of proinflammatory (interleukin [IL]-6 and tumor necrosis factor [TNF]) and anti-inflammatory (IL-10 and transforming growth factor [TGF]-β) adipokines in the blood, subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) of metabolically healthy class III obese individuals and normal-weight controls. METHODS The serum concentrations (enzyme-linked immunosorbent assay [ELISA]), mRNA expression levels (reverse transcriptase polymerase chain reaction), and adipose tissue secretion (ELISA) of IL-6, TNF, IL-10, and TGF-β were analyzed, as were the mRNA expression of FOXP3 (present in regulatory T cells) and the secretion (Western blotting) of matrix metalloproteinases in the adipose tissue. RESULTS There were no differences in the circulating levels, expression, or secretion of IL-6 and TNF between the groups or tissues. The expression and circulating levels of IL-10 were higher in obese individuals, especially in the SAT. Although the blood concentration of TGF-β was similar between the groups, its expression and secretion levels were higher in the adipose tissues of obese individuals compared with controls. FOXP3 and MMP expression levels were higher in the SAT and VAT of obese individuals, respectively, compared with the controls. CONCLUSION Metabolically healthy, extremely obese individuals have effective immunoregulation to counter chronic obesity-related inflammation through the increased production of the anti-inflammatory cytokines IL-10 and TGF-β in adipose tissue, especially SAT; the increased presence of FOXP3-positive regulatory T cells; and increases in angiogenesis and adipogenesis induced by TGF-β and MMPs. These regulatory mechanisms could be important in the delayed onset of metabolic complications, even in extremely obese individuals.

Lack of platelet-activating factor receptor protects mice against diet-induced adipose inflammation and insulin-resistance despite fat pad expansion.

The role of platelet‐activating factor (PAF) on diet‐induced inflammatory and metabolic dysfunction is unknown. The effects of diet‐induced metabolic and inflammatory dysfunction in mice with deletion of the PAF receptor (PAFR−/−) were evaluated in this study.

Acute intake of a high-fructose diet alters the balance of adipokine concentrations and induces neutrophil influx in the liver☆☆☆

The postprandial state is a period of metabolic fluxes, biosynthesis and oxidative metabolism. A considerable amount is known about the inflammatory response to the chronic consumption of fructose, but little is known about its effects in the postprandial state. The aim of the present study was to investigate the inflammatory effects of a single meal containing fructose on healthy mice. Male BALB/c and LysM-eGFP mice at 12-14 weeks were divided into three groups: fasted, control (mice fed with a sucrose-containing diet) and fructose (mice fed with a fructose-containing diet). One, 2 or 4 h postprandial, the BALB/c mice were killed, and samples were collected. LysM-eGFP mice were submitted to intravital microscopy. The fed mice showed a low-grade inflammatory response apart from dietary composition, which was characterized by increased numbers of leukocytes and high serum concentrations of pentraxin 3, leptin and resistin. TNF-α and CCL2 concentrations rose in the liver after the meal. IL-6 concentration increased and IL-10 decreased in the adipose tissue of the fed mice. Mice fed with the fructose-containing diet showed an intensification of the inflammatory response. Furthermore, the adiponectin concentration dropped, and the liver influx of neutrophils increased after fructose intake. Overall, this study showed a rapid increase in the systemic and tissue-specific immune response after a balanced meal. The study also showed an increased neutrophil influx in liver associated with an imbalance of adipokine concentrations and an increase of cytokine in the liver and adipose tissue following a fructose-containing meal.

Integrated Monitoring of Mola mola Behaviour in Space and Time.

Over the last decade, ocean sunfish movements have been monitored worldwide using various satellite tracking methods. This study reports the near-real time monitoring of fine-scale (< 10 m) behaviour of sunfish. The study was conducted in southern Portugal in May 2014 and involved satellite tags and underwater and surface robotic vehicles to measure both the movements and the contextual environment of the fish. A total of four individuals were tracked using custom-made GPS satellite tags providing geolocation estimates of fine-scale resolution. These accurate positions further informed sunfish areas of restricted search (ARS), which were directly correlated to steep thermal frontal zones. Simultaneously, and for two different occasions, an Autonomous Underwater Vehicle (AUV) video-recorded the path of the tracked fish and detected buoyant particles in the water column. Importantly, the densities of these particles were also directly correlated to steep thermal gradients. Thus, both sunfish foraging behaviour (ARS) and possibly prey densities, were found to be influenced by analogous environmental conditions. In addition, the dynamic structure of the water transited by the tracked individuals was described by a Lagrangian modelling approach. The model informed the distribution of zooplankton in the region, both horizontally and in the water column, and the resultant simulated densities positively correlated with sunfish ARS behaviour estimator (rs = 0.184, p<0.001). The model also revealed that tracked fish opportunistically displace with respect to subsurface current flow. Thus, we show how physical forcing and current structure provide a rationale for a predator’s fine-scale behaviour observed over a two weeks in May 2014.

Carbohydrate-enriched diet predispose to anxiety and depression-like behavior after stress in mice

Objectives: Obesity is a chronic disease frequently associated with serious co-morbidities, such as diabetes type II, metabolic syndrome, and psychiatric disorders. Little is known, however, regarding the behavioral consequences of modified diet constituents and the propensity to development of stress related disorders. Thus, the aim of this study was to verify whether chronic exposure to a normocaloric/high-carbohydrate diet will modify the animals behavior after different stressful stimuli. Methods: BALB/c mice were fed for 12 weeks with a standard chow diet or high refined carbohydrate-containing diet (HC). Following this period, independent groups of animals were exposed to different stress paradigms: 1 – two hours of restraint stress followed by exposure to the Elevated Plus Maze test (EPM) 24 hours later; 2 – The contextual fear conditioning (CFC) test and 3 – the tail suspension test (TST). Results: Despite no change on total body weight, animals fed with HC diet showed increase in serum leptin levels and higher adiposity compared to diet control group. In behavioral tests, animals from HC diet group displayed reduction in the percentage of entries into the open arms of the EPM, evaluated 24 hours after restraint stress, suggesting an anxiogenic-like effect. It is also observed increase in aversive memory in the CFC test and depressive-like behavior in TST. Discussion: Our results suggest that a moderate obesity, induced by high refined carbohydrate diet, may facilitate the development of anxiety and depressive-like behaviors after the stress. The mechanisms responsible for such effects remain to be elucidated.

Tumor Necrosis Factor, but Not Neutrophils, Alters the Metabolic Profile in Acute Experimental Arthritis

Metabolic alterations are associated with arthritis apart from obesity. However, it is still unclear which is the underlying process behind these metabolic changes. Here, we investigate the role of tumor necrosis factor (TNF) in this process in an acute model of antigen-induced arthritis (AIA). Immunized male BALB/c mice received an intra-articular injection of PBS (control) or methylated bovine serum albumin (mBSA) into their knees, and were also pre-treated with different drugs: Etanercept, an anti-TNF drug, DF2156A, a CXCR1/2 receptor antagonist, or a monoclonal antibody RB6-8C5 to deplete neutrophils. Local challenge with mBSA evoked an acute neutrophil influx into the knee joint, and enhanced the joint nociception, along with a transient systemic metabolic alteration (higher levels of glucose and lipids, and altered adipocytokines). Pre-treatment with the conventional biological Etanercept, an inhibitor of TNF action, ameliorated the nociception and the acute joint inflammation dominated by neutrophils, and markedly improved many of the altered systemic metabolites (glucose and lipids), adipocytokines and PTX3. However, the lessening of metabolic changes was not due to diminished accumulation of neutrophils in the joint by Etanercept. Reduction of neutrophil recruitment by pre-treating AIA mice with DF2156A, or even the depletion of these cells by using RB6-8C5 reduced all of the inflammatory parameters and hypernociception developed after AIA challenge, but could not prevent the metabolic changes. Therefore, the induction of joint inflammation provoked acute metabolic alterations which were involved with TNF. We suggest that the role of TNF in arthritis-associated metabolic changes is not due to local neutrophils, which are the major cells present in this model, but rather due to cytokines.

Milk-Derived Nanoparticle Fraction Promotes the Formation of Small Osteoclasts But Reduces Bone Resorption

The general consensus is that milk promotes bone growth and density because is a source of calcium and contains components that enhance intestinal calcium uptake or directly affect bone metabolism. In this study, we investigated the effect of bovine‐derived milk 100,000 g pellet (P100), which contains nanoparticles (<220 nm) including extracellular vesicles, on osteoclast differentiation and bone resorption. Bone marrow‐derived osteoclast precursor cells were differentiated into osteoclasts by M‐CSF and RANKL (control) and in the presence of milk P100. Milk P100 treatment until day 4 increased the number of TRAP‐positive mononuclear cells and small (≤5 nuclei) osteoclasts. The number of large (≥6 nuclei) osteoclasts remained the same. These alterations were associated with increased expression of TRAP, NFATc1, and c‐Fos. Cells seeded in a calcium‐phosphate coated plate or bone slices showed reduced resorption area when exposed to milk P100 during the differentiation phase and even after osteoclast formation. Interestingly, milk P100 treatment enhanced Cathepsin K expression but reduced Carbonic Anhydrase 2 gene expression. Moreover, intracellular acid production was also decreased by milk P100 treatment. Oral delivery of milk P100 to female DBA1/J mice for 7 weeks did not alter bone area; however, increased osteoclast number and area in tibia without changes in serum RANKL and CTX‐I levels. We showed for the first time the effect of milk P100 on osteoclast differentiation both in vitro and in vivo and found that milk P100 increased the formation of small osteoclasts but this does not lead to more bone resorption probably due to reduced acid secretion. J. Cell. Physiol. 232: 225–233, 2017.

Kernel Partial Least Squares for person re-identification

Person re-identification (Re-ID) keeps the same identity for a person as he moves along an area with nonoverlapping surveillance cameras. Re-ID is a challenging task due to appearance changes caused by different camera viewpoints, occlusion and illumination conditions. While robust and discriminative descriptors are obtained combining texture, shape and color features in a high-dimensional representation, the achievement of accuracy and efficiency demands dimensionality reduction methods. At this paper, we propose variations of Kernel Partial Least Squares (KPLS) that simultaneously reduce the dimensionality and increase the discriminative power. The Cross-View KPLS (X-KPLS) and KPLS Mode A capture cross-view discriminative information and are successful for unsupervised and supervised Re-ID. Experimental results demonstrate that X-KPLS presents equal or higher matching results when compared to other methods in literature at PRID450S.