Disintegration of the colonic epithelial barrier is considered a key event in the initiation and progression of inflammatory bowel and celiac disease. As the primary etiology of these diseases remains unknown, we hypothesized that the trichothecene deoxynivalenol (DON), a fungal metabolite found in grain-based human diets, might be one of the triggers resulting in an impairment of the intestinal tight junction network preceding an inflammatory response. Using horizontal impedance measurements, we demonstrate that DON disintegrates a human Caco-2 cell monolayer within <1 h after exposure to concentrations as low as 1.39 μM. This initial trigger is followed by a decrease in transepithelial resistance and an increased permeability of marker molecules, such as lucifer yellow and FITC-labeled dextran. In parallel, the increase in paracellular transport of FITC-dextran is demonstrated in vivo in B6C3F1 mice, challenged orally with DON. In vitro claudin protein levels are decreased and correlated with a displacement within the cells in vitro and in vivo, accompanied by a compensatory up-regulation of mRNA levels of claudins and their binding partner ZO-1. In treated mice, alterations in villus architecture in the entire intestinal tract resemble the disintegration of the epithelial barrier, a characteristic of chronic inflammatory bowel disease.

The results demonstrate that GOSs stimulate the tight junction assembly and in turn mitigate the deleterious effects of deoxynivalenol on the intestinal barrier of Caco-2 cells and on villus architecture of B6C3F1 mice.

Epidemiological studies show an inverse relation between raw cow’s milk consumption and the development of asthma. This protective effect seems to be abolished by milk processing. However, evidence for a causal relationship is lacking, and direct comparisons between raw and processed milk are hardly studied. Therefore, this study investigated the preventive capacity of raw and heated raw milk on the development of house dust mite (HDM)-induced allergic asthma in mice. Six- to seven-week-old male BALB/c mice were intranasally (i.n.) sensitized with 1 µg HDM or PBS on day 0, followed by an i.n. challenge with 10 µg HDM or PBS on days 7–11. In addition, mice were fed 0.5 mL raw cow’s milk, heated raw cow’s milk, or PBS three times a week throughout the study, starting 1 day before sensitization. On day 14, airway hyperresponsiveness (AHR) in response to increasing doses of methacholine was measured to assess lung function. Bronchoalveolar lavage fluid (BALF) and lungs were furthermore collected to study the extent of airway inflammation. Raw milk prevented both HDM-induced AHR and pulmonary eosinophilic inflammation, whereas heated raw milk did not. Both milk types suppressed the Th2-polarizing chemokine CCL17 in lung homogenates and reduced lung Th2 and Th17 cell frequency. IL-4 and IL-13 production after ex vivo restimulation of lung T cells with HDM was also reduced by both milk types. However, local IL-5 and IL-13 concentrations were only suppressed by raw milk. These findings support the asthma-protective capacity of raw cow’s milk and show the importance of reduced local type 2 cytokine levels. Heated raw milk did not show an asthma-protective effect, which indicates the involvement of heat-sensitive components. Besides causal evidence, this study provides the basis for further mechanistic studies.

Emphysema is characterized by enlargement of the alveoli, which is the most important parameter to assess the presence and severity of this disease. Alveolar enlargement is primarily defined on morphological criteria; therefore, characterization of this disease with morphological parameters is a prerequisite to study the pathogenesis. For this purpose, different methods of lung fixation were evaluated in a murine model of LPS-induced lung emphysema. Five different methods of lung fixation were evaluated: intratracheal instillation of fixatives, in situ fixation, fixed-volume fixation, vascular whole body perfusion, and vacuum inflation. In addition, the effects of three different fixatives (10% formalin, Carnoy's, and agarose/10% formalin solution) and two embedding methods (paraffin and plastic) were investigated on the murine lung morphology. Mice received intranasal administration of LPS to induce alveolar wall destruction. Quantification of air space enlargement was determined by mean linear intercept analysis, and the histological sections were analyzed for the most optimal fixation method. Additionally, routine immunohistological staining was performed on lung tissue of PBS-treated mice. Intratracheal instillation of formalin or agarose/formalin solution, in situ fixation, and fixed-volume fixation provided a normal lung architecture, in contrast to the lungs fixed via whole body perfusion and vacuum inflation. Formalin-fixed lungs resulted in the most optimal lung morphology for lung emphysema analysis when embedded in paraffin, while for Carnoy's fixed lungs, plastic embedding was preferred. The histological findings, the mean linear intercept measurement, and the immunohistochemistry data demonstrated that fixation by intratracheal instillation of 10% formalin or in situ fixation with 10% formalin are the two most optimal methods to fix lungs for alveolar enlargement analysis to study lung emphysema.

We elucidated a novel mechanism that links TRPC6 activity to calpain-1 activation and through Talin-1 loss and possibly, calcineurin activation, the podocyte injury characterizing FSGS. Therefore, calpain-1 and/or TRPC6 inhibition could be future therapeutic options to treat patients with FSGS or other podocytopathies.

Background: Allergic asthma is strongly associated with the exposure to house dust mite (HDM) and is characterized by eosinophilic pulmonary inflammation and airway hyperresponsiveness (AHR). Recently, there is an increased interest in using dietary oligosaccharides, also known as prebiotics, as a novel strategy to prevent the development of, or reduce, symptoms of allergy.

Purpose The incidence and severity of allergic asthma is rising, and novel strategies to prevent or treat this disease are needed. This study investigated the effects of different mixtures of non-digestible oligosaccharides combined with Bifidobacterium breve M-16V (BB) on the development of allergic airway inflammation in an animal model for house dust mite (HDM)-induced allergic asthma.MethodsBALB/c mice were sensitized intranasally (i.n.) with HDM and subsequently challenged (i.n.) with PBS or HDM while being fed diets containing different oligosaccharide mixtures in combination with BB or an isocaloric identical control diet. Bronchoalveolar lavage fluid (BALF) inflammatory cell influx, chemokine and cytokine concentrations in lung homogenates and supernatants of ex vivo HDM-restimulated lung cells were analyzed.ResultsThe HDM-induced influx of eosinophils and lymphocytes was reduced by the diet containing the short-chain and long-chain fructo-oligosaccharides and BB (FFBB). In addition to the HDM-induced cell influx, concentrations of IL-33, CCL17, CCL22, IL-6, IL-13 and IL-5 were increased in supernatants of lung homogenates or BALF and IL-4, IFN-γ and IL-10 were increased in restimulated lung cell suspensions of HDM-allergic mice. The diet containing FFBB reduced IL-6, IFN-γ, IL-4 and IL-10 concentrations, whereas the combination of galacto-oligosaccharides and long-chain fructo-oligosaccharides with BB was less potent in this model.ConclusionThese findings show that synbiotic dietary supplementation can affect respiratory allergic inflammation induced by HDM. The combination of FFBB was most effective in the prevention of HDM-induced airway inflammation in mice.

In this study a direct comparison was made between non-invasive and non-ventilated unrestrained whole body plethysmography (Penh) (conscious animals) and the invasive ventilated lung resistance (RL) method (anesthetized animals) in both mild and severe allergic airway inflammation models. Mild inflammation was induced by intraperitoneal sensitization and aerosols of ovalbumin. Severe inflammation was induced by intraperitoneal sensitization using trinitrophenyl-ovalbumin, followed by intranasal challenges with IgE-allergen complexes. A significant increase in airway responsiveness to methacholine was observed in the mild inflammation group when RL was measured. Significant changes in both RL and Penh were observed in the severe inflammation groups. There was a significant increase in the number of inflammatory cells in the Broncho-Alveolar Lavage Fluid (BALF) in both the mild and severe inflammation animals. The enforced ventilation of the animals during the RL measurement further increased the number of cells in the BALF. IL-2 and RANTES levels in the BALF were higher in the severe inflammation groups compared to the mild inflammation groups. Penh gave only reliable measurements during severe airway inflammation. Measuring RL gave consistent results in both mild and severe allergic airway inflammation models however, ventilation induced an additional cell influx into the airways.