Differential effects of high fat diet-induced obesity on oocyte mitochondrial functions in inbred and outbred mice

Maternal obesity can cause reduced oocyte quality and subfertility. Mitochondrial dysfunction plays a central role here, and most often inbred mouse models are used to study these pathways. We hypothesized that the mouse genetic background can influence the impact of high fat diet (HFD)-induced obesity on oocyte quality. We compared the inbred C57BL/6 (B6) and the outbred Swiss strains after feeding a HFD for 13w. HFD-mice had increased body weight gain, hypercholesterolemia, and increased oocyte lipid droplet (LD) accumulation in both strains. LD distribution was strain-dependent. In Swiss mouse oocytes, HFD significantly increased mitochondrial inner membrane potential (MMP), reactive oxygen species concentrations, mitochondrial ultrastructural abnormalities (by 46.4%), and endoplasmic reticulum (ER) swelling, and decreased mtDNA copy numbers compared with Swiss controls (P0.1). Interestingly, mtDNA in B6-HFD oocytes was increased suggesting defective mitophagy. In conclusion, we show evidence that the genetic background or inbreeding can affect mitochondrial functions in oocytes and may influence the impact of HFD on oocyte quality. These results should create awareness when choosing and interpreting data obtained from different mouse models before extrapolating to human applications

Not all pediatric intestinal polyps are alike

Background/Aims : In childhood, clinical presentation of intestinal polyps is variable. Painless rectal red blood loss is the most common presenting sign. Most polyps are sporadic, isolated and benign. However, it is important to correctly identity exceptions. Hare inherited polyposis syndromes need to be recognized because of their increased risk of intestinal and extra-intestinal malignancies. Furthermore, a correct diagnosis and treatment of rare gastro-intestinal malignancies is crucial. Methods : Between 2016 and 2018 we encountered 4 different types of intestinal polyps. A database search was performed and patient tiles were checked for clinical manifestations and histopathology. Literature was searched to recapitulate red flags for these syndromes, probability of underlying genetic disorders and diagnostic criteria. Results : Between 2016 and 2018, 28 patients presented at the Ghent University Hospital with 30 juvenile polyps. Furthermore, we diagnosed juvenile polyposis syndrome, Li Fraumeni syndrome and familial adenomatous polyposis (FAP) in 1 patient each, whilst 2 FAP patients were in follow-up. Each of these diagnoses has a different lifetime risk of (extra)-intestinal malignancy and requires a different approach and follow-up. Histopathology and genetic testing play an important role in identifying these syndromes in pediatric patients. Conclusion : Although most intestinal polyps in childhood are benign juvenile polyps that require no follow-up, rare inherited syndromes should be considered and correctly diagnosed since adequate follow-up is necessary to reduce morbidity and mortality from both gastrointestinal and extraintestinal complications and malignancies

Aggravation of allergic airway inflammation by cigarette smoke in mice is CD44-dependent

Background : Although epidemiological studies reveal that cigarette smoke (CS) facilitates the development and exacerbation of allergic asthma, these studies offer limited information on the mechanisms involved. The transmembrane glycoprotein CD44 is involved in cell adhesion and acts as a receptor for hyaluronic acid and osteopontin. We aimed to investigate the role of CD44 in a murine model of CS-facilitated allergic airway inflammation. Methods : Wild type (WT) and CD44 knock-out (KO) mice were exposed simultaneously to house dust mite (HDM) extract and CS. Inflammatory cells, hyaluronic acid (HA) and osteopontin (OPN) levels were measured in bronchoalveolar lavage fluid (BALF). Proinflammatory mediators, goblet cell metaplasia and peribronchial eosinophilia were assessed in lung tissue. T-helper (Th) 1, Th2 and Th17 cytokine production was evaluated in mediastinal lymph node cultures. Results : In WT mice, combined HDM/CS exposure increased the number of inflammatory cells and the levels of HA and OPN in BALF and Th2 cytokine production in mediastinal lymph nodes compared to control groups exposed to phosphate buffered saline (PBS)/CS, HDM/Air or PBS/Air. Furthermore, HDM/CS exposure significantly increased goblet cell metaplasia, peribronchial eosinophilia and inflammatory mediators in the lung. CD44 KO mice exposed to HDM/CS had significantly fewer inflammatory cells in BALF, an attenuated Th2 cytokine production, as well as decreased goblet cells and peribronchial eosinophils compared to WT mice. In contrast, the levels of inflammatory mediators were similar or higher than in WT mice. Conclusion : We demonstrate for the first time that the aggravation of pulmonary inflammation upon combined exposure to allergen and an environmental pollutant is CD44-dependent. Data from this murine model of concomitant exposure to CS and HDM might be of importance for smoking allergic asthmatics

Short-term cigarette smoke exposure enhances allergic airway inflammation in mice

Rationale: Epidemiologic studies suggest that tobacco smoke contributes to the prevalence and occurrence of exacerbations in asthma. The effect of active smoking in adolescents with atopy is poorly understood. Objectives: We developed an experimental model to investigate the influence of smoking on antigen-induced airway inflammation and airway responsiveness in mice that were previously sensitized. Methods: Ovalbumin (OVA)-sensitized BALB/c mice were exposed to air or mainstream smoke (S days/week) and to phosphate-buffered saline (PBS) or OVA aerosol (3 times/week) for 2 weeks (n = 8 for each group). Results: Airway responsiveness to intravenously injected carbachol was increased (p < 0.05) in smoke- and OVA-exposed mice compared with all other groups. There was an additive effect of smoke and OVA exposure on total cell numbers, macrophages, and dendritic cells in bronchoalveolar lavage fluid and on CD4(+) and CD8(+) T lymphocytes and dendritic cells in lung tissue (p < 0.05 compared with mice exposed to smoke and PBS and to mice exposed to air and OVA). Concurrent smoke and OVA exposure augmented OVA-specific IgE in serum compared with air and OVA exposure. In lavage fluid supernatant, eotaxin was increased in air- and OVA-exposed mice. The further increase observed in the group exposed to both OVA and cigarette smoke came close to formal significance (p = 0.06). Thymus- and activation-regulated chemokine was augmented in mice exposed to either smoke or OVA, without additional effect. Conclusions: Our data indicate that acute concurrent exposure to allergen and mainstream cigarette smoke enhances airway inflammation and airway responsiveness in previously sensitized mice

Roken en astma

Asthma is a frequently occurring disease with an increasing prevalence worldwide, that is the highest in childhood. Smoking, both active and passive, is also a widespread problem. Epidemiological and experimental studies show that active and passive smoking have an important influence on the severity and the development of asthma. There is sufficient evidence to conclude that there is a relationship between passive smoking and both the exacerbation and the development of asthma in children. In adults, there is sufficient evidence for a relationship between passive smoking and the exacerbation of asthma, but there is only suggestive evidence for the relationship between passive smoking and the development of asthma. There is sufficient evidence for a relationship between active smoking and the exacerbation of asthma in anybody who smokes. Besides, active smoking impairs the efficacy of inhaled corticosteroid treatment in asthma. There is no evidence for a causal relationship between active smoking and the development of asthma. Children of mothers who smoked during pregnancy or young children who are exposed to environmental tobacco smoke, are at the highest risk to develop asthma during their life. Consequently, every physician plays an important role in helping pregnant women, parents of young children and asthmatic patients (and as a matter of fact every smoker) to stop smoking.Astma is een veelvoorkomende aandoening waarvan de prevalentie wereldwijd toeneemt en het hoogst is tijdens de kinderjaren. Roken, zowel actief als passief, is eveneens een wijdverspreid probleem. Epidemiologische en experimentele studies tonen aan dat passief en actief roken een belangrijke invloed hebben op de ontwikkeling en de ernst van astma. Er is voldoende bewijs om te besluiten dat er een verband is tussen passief roken en zowel de verergering als de ontwikkeling van astma bij kinderen. Bij volwassenen is er voldoende bewijs voor een verband tussen passief roken en de verergering van astma, maar een slechts suggestief bewijs voor een verband tussen passief roken en de ontwikkeling van astma. Er is voldoende bewijs dat er een verband is tussen actief roken en de verergering van astma. Bovendien vermindert actief roken de werkzaamheid van inhalatiecorticosteroïden in de behandeling van astma. Een oorzakelijk verband tussen actief roken en de ontwikkeling van astma is niet bewezen. Kinderen van moeders die tijdens de zwangerschap hebben gerookt, of jonge kinderen die in hun omgeving worden blootgesteld aan rook, zijn de grootste risicogroep om later astma te ontwikkelen. Elke arts heeft bijgevolg een belangrijke rol om zwangere vrouwen, ouders met jonge kinderen en astmapatiënten (en in feite iedereen) te helpen stoppen met roken

Short-Term Cigarette Smoke Exposure Enhances Allergic Airway Inflammation in Mice

Rationale: Epidemiologic studies suggest that tobacco smoke contributes to the prevalence and occurrence of exacerbations in asthma. The effect of active smoking in adolescents with atopy is poorly understood. Objectives: We developed an experimental model to investigate the influence of smoking on antigen-induced airway inflammation and airway responsiveness in mice that were previously sensitized. Methods: Ovalbumin (OVA)-sensitized BALB/c mice were exposed to air or mainstream smoke (S days/week) and to phosphate-buffered saline (PBS) or OVA aerosol (3 times/week) for 2 weeks (n = 8 for each group). Results: Airway responsiveness to intravenously injected carbachol was increased (p < 0.05) in smoke- and OVA-exposed mice compared with all other groups. There was an additive effect of smoke and OVA exposure on total cell numbers, macrophages, and dendritic cells in bronchoalveolar lavage fluid and on CD4(+) and CD8(+) T lymphocytes and dendritic cells in lung tissue (p < 0.05 compared with mice exposed to smoke and PBS and to mice exposed to air and OVA). Concurrent smoke and OVA exposure augmented OVA-specific IgE in serum compared with air and OVA exposure. In lavage fluid supernatant, eotaxin was increased in air- and OVA-exposed mice. The further increase observed in the group exposed to both OVA and cigarette smoke came close to formal significance (p = 0.06). Thymus- and activation-regulated chemokine was augmented in mice exposed to either smoke or OVA, without additional effect. Conclusions: Our data indicate that acute concurrent exposure to allergen and mainstream cigarette smoke enhances airway inflammation and airway responsiveness in previously sensitized mice