SciCombinator

Discover the most talked about and latest scientific content & concepts.

Journal: Clinical science (London, England : 1979)

27

Human endometrium is a highly dynamic tissue, undergoing periodic growth and regression at each menstrual cycle. Endometriosis is a frequent chronic pathological status characterized by endometrial tissue with an ectopic localization, causing pelvic pain and infertility and a variable clinical presentation. In addition, there is well-established evidence that, although endometriosis is considered benign, it is associated with an increased risk of malignant transformation in approximately 1.0% of affected women, with the involvement of multiple pathways of development. Increasing evidence supports a key contribution of different stem/progenitor cell populations not only in the cyclic regeneration of eutopic endometrium, but also in the pathogenesis of at least some types of endometriosis. Evidence has arisen from experiments in animal models of disease through different kinds of assays (including clonogenicity, the label-retaining cell approach, the analysis of undifferentiation markers), as well as from descriptive studies on ectopic and eutopic tissue samples harvested from affected women. Changes in stem cell populations in endometriotic lesions are associated with genetic and epigenetic alterations, including imbalance of miRNA expression, histone and DNA modifications and chromosomal aberrations. The present short review mainly summarizes the latest observations contributing to the current knowledge regarding the presence and the potential contribution of stem/progenitor cells in eutopic endometrium and the aetiology of endometriosis, together with a report of the most recently identified genetic and epigenetic alterations in endometriosis. We also describe the potential advantages of single cell molecular profiling in endometrium and in endometriotic lesions. All these data can have clinical implications and provide a basis for new potential therapeutic applications.

Concepts: DNA, Gene, Cell, Histone, Chromosome, Menstrual cycle, Endometrium, Endometriosis

27

Diabetic mice are characterized by a disrupted expression pattern of vascular-endothelial-growth-factor (VEGF), and impaired vasculogenesis during healing. Experimental evidence suggest that relaxin (RLX) can improve several parameters associated with wound healing. Therefore, we investigated the effects of porcine derived relaxin in diabetes-related wound healing defects in genetically diabetic mice. An incisional wound model was produced on the back of female diabetic C57BL/KsJ-m+/+Leptdb (db+/db+) mice and their normal littermates (db+/+m). Animals were treated daily with porcine RLX (25µg mouse/day/s.c.) or its vehicle. Mice were killed on 3, 6 and 12 days after skin injury for measurements of VEGF mRNA and protein synthesis, stromal cell-derived factor-1α (SDF-1α) mRNA and endothelial nitric oxide synthase (eNOS) expression. Furthermore, we evaluated wound-breaking strength, histological changes, angiogenesis and vasculogenesis at day 12. Diabetic animals showed a reduced expression of VEGF, eNOS and SDF-1α compared to nondiabetic animals. At day 6, RLX administration resulted in an increase in VEGF mRNA expression and protein wound content, in eNOS expression and in SDF-1α mRNA. Furthermore the histological evaluation indicated that RLX improved the impaired wound healing, enhanced the staining of matrix metalloproteinase-11 (MMP-11) and increased wound breaking strength at day 12 in diabetic mice. Immunohistochemistry showed that RLX in diabetic animals augmented new vessel formation by stimulating both angiogenesis and vasculogenesis. RLX significantly reduced the time to complete skin normalization and this effect was abrogated by a concomitant treatment with antibodies against VEGF and CXCR4, the SDF-1α receptor. These data strongly suggest that RLX may have a potential application in diabetes-related wound disorders.

Concepts: DNA, Protein, Wound healing, Angiogenesis, Messenger RNA, Endothelium, Nitric oxide, Nitric oxide synthase

26

Real-word evaluation studies have shown that many patients with asthma remain symptomatic despite treatment with inhaled corticosteroids (ICS). As conventional ICS have poor access to the peripheral airways, the aim of present study was to study the relationship between peripheral airway inflammation and clinical control in allergic asthma. Consequently, bronchial and transbronchial biopsies were obtained from poorly controlled asthmatics (n=12, Asthma Control Test (ACT) score <20), well-controlled asthmatics (n=12, ACT score ≥20) and healthy controls (n=8). Tissue sections were immunostained to assess multiple leukocyte populations. To determine the degree of T helper type 2 (Th2) immunity, the logarithmic value of the ratio between Th2 cells/mm2 and Th1 cells/mm2 was used as a surrogate score for Th2 skewed immunity. In the bronchi, the leukocyte infiltration pattern and the Th2-score were similar between well-controlled and poorly controlled asthmatics. In contrast, in the alveolar parenchyma the expression of T helper cells was significant higher in poorly controlled asthmatics compared to well-controlled asthmatics (p<0.01). Furthermore, the alveolar Th2-score was significantly higher in poorly controlled asthma (median 0.4) compared to the controlled patients (median -0.10, p<0.05). Additionally, in contrast to bronchial Th2-score, the alveolar Th2-score correlated significantly with ACT score (rs=-0.56, p<0.01) in the pooled asthma group. Collectively, our data reveal an alveolar Th2-skewed inflammation specifically in asthma patients that are poorly controlled with ICS and suggest that pharmacological targeting of the peripheral airways may be beneficial in this large patient category.

Concepts: AIDS, Immune system, White blood cell, Asthma, Immunology, Allergy, T helper cell, Bronchiole

23

Abdominal aortic aneurysm (AAA) evolution is unpredictable. Moreover, no specific treatment exists for AAA, except surgery to prevent aortic rupture. Galectin-3 has been previously associated with CVD, but its potential role in AAA have not been addressed. Galectin-3 levels were increased in plasma of AAA patients (n=225) compared to controls (n=100). Moreover, galectin-3 concentrations were associated with need for surgical repair, independently of potential confounding factors. Galectin-3 mRNA and protein expression were increased in human AAA samples compared to healthy aortas. Experimental AAA in mice was induced by aortic elastase perfusion. Mice were treated i.v. with the galectin-3 inhibitor modified citrus pectin (MCP, 10mg/kg, every other day) or saline. Similar to humans, galectin-3 serum and aortic mRNA levels were also increased in elastase-induced AAA mice compared to control mice. Mice treated with MCP showed decreased aortic dilation, as well as elastin degradation, VSMC loss and macrophage content at day 14 post-elastase perfusion compared with control mice. The underlying mechanism(s) of the protective effect of MCP was associated to a decrease in galectin-3 and cytokine (mainly CCL5) mRNA and protein expression. Interestingly, galectin-3 induced CCL5 expression by a mechanism involving STAT3 activation in VSMC. Accordingly, MCP treatment decreased STAT3 phosphorylation in elastase-induced AAA. In conclusion, increased galectin-3 levels are associated with AAA progression, while galectin-3 inhibition decreased experimental AAA development. Our data suggest the potential role of galectin-3 as a therapeutic target in AAA.

Concepts: Protein, Gene expression, Aortic aneurysm, Aneurysm, Aortic dissection, Aorta, Abdominal aortic aneurysm, Aneurysm of sinus of Valsalva

23

The pathogenesis of asthma is complex and multi-faceted. Asthma patients have a diverse range of underlying dominant disease processes and pathways despite apparent similarities in clinical expression. Here, we present the current understanding of asthma pathogenesis. We discuss airway inflammation (both T2(HIGH) and T2(LOW)), airway hyperresponsiveness (AHR) and airways remodelling as four key factors in asthma pathogenesis, and also outline other contributory factors such as genetics and co-morbidities. Response to current asthma therapies also varies greatly, which is probably related to the inter-patient differences in pathogenesis. Here, we also summarize how our developing understanding of detailed pathological processes potentially translates into the targeted treatment options we require for optimal asthma management in the future.

Concepts: Immune system, Inflammation, Medicine, Gene expression, Asthma, Pathology, Future, Futures contract

11

β2-adrenoceptor agonists are the mainstay therapy for patients with asthma but their effectiveness in cigarette smoke (CS)-induced lung disease such as chronic obstructive pulmonary disease (COPD) is limited. In addition, bronchodilator efficacy of β2-adrenoceptor agonists is decreased during acute exacerbations of COPD (AECOPD), caused by respiratory viruses including influenza A. Therefore, the aim of the present study was to assess the effects of the β2-adrenoceptor agonist salbutamol (SALB) on small airway reactivity using mouse precision cut lung slices (PCLS) prepared from CS-exposed mice and from CS-exposed mice treated with influenza A virus (Mem71, H3N1). CS exposure alone reduced SALB potency and efficacy associated with decreased β2-adrenoceptor mRNA expression, and increased tumour necrosis factor α (TNFα) and interleukin-1β (IL-1β) expression. This impaired relaxation was restored by day 12 in the absence of further CS exposure. In PCLS prepared after Mem71 infection alone, responses to SALB were transient and were not well maintained. CS exposure prior to Mem71 infection almost completely abolished relaxation, although β2-adrenoceptor and TNFα and IL-1β expression were unaltered. The present study has shown decreased sensitivity to SALB after CS or a combination of CS and Mem71 occurs by different mechanisms. In addition, the PCLS technique and our models of CS and influenza infection provide a novel setting for assessment of alternative bronchodilators.

Concepts: Pulmonology, Asthma, Virus, Pneumonia, Tobacco smoking, Chronic obstructive pulmonary disease, Obstructive lung disease, Bronchodilator

8

In PCOS women, hyperinsulinemia stimulates ovarian cytochrome P450c17α activity that, in turn, stimulates ovarian androgen production. Our objective was to compare whether timed caloric intake differentially influences insulin resistance and hyperandrogenism in lean PCOS women. Sixty lean PCOS women (BMI 23.7±0.2kg/m2) were randomized into two isocaloric (~1800kcal) maintenance diets with different meal timing distribution: a breakfast diet (BF) (980kcal breakfast, 640kcal lunch, 190kcal dinner) or a dinner diet (D) group (190kcal breakfast, 640kcal lunch, 980kcal dinner) for 90 days. In the BF group, a significant decrease was observed in both AUCglucose and AUCinsulin, by 7 and 54%, respectively. In the BF group, free testosterone decreased by 50% and SHBG increased by 105%. GnRH-stimulated peak serum 17α hydroxyprogesterone decreased by 39%. No change in these parameters was observed in the D group. In addition, women in the BF group presented increased ovulation rate. In lean PCOS women, a high caloric intake at breakfast with reduced intake at dinner results in improved insulin sensitivity indices and reduced cytochrome P450c17α activity, which ameliorates hyperandrogenism and improves ovulation rate. Meal timing and distribution should be considered as a therapeutic option for women with PCOS.

Concepts: Estrogen, Luteinizing hormone, Metformin, Polycystic ovary syndrome

4

Quitting smoking is the most important step smokers can take to improve their health. Nonetheless, there is little information on long-term improvements in lung function and/or respiratory symptoms after smoking cessation. Here we illustrate long-term changes in spirometric indices as well as in respiratory symptoms in smokers invited to quit or reduce their cigarette consumption by switching to electronic cigarettes. Prospective evaluation of cigarette consumption, spirometry and symptoms was performed in a 1-year randomized controlled trial of smokers receiving electronic cigarette containing 2.4%, 1.8%, or 0% nicotine. Spirometric data are presented on the basis of participants' pooled continuous smoking phenotype classification (Quitters, Reducers, Failures), whereas respiratory symptoms on point prevalence-smoking phenotype. Smoking phenotype classification (Quitters, Reducers, Failures) had no significant effect on spirometric indices (FEV1, FVC, and FEV1/FVC) with the exception of FEF25-75%, which significantly (p=0.034) increased over the time among Quitters; their FEF25-75% (% predicted) improving from (means±SD) 85.7±15.6% at baseline to 100.8±14.6%. High prevalence of cough/phlegm (43.1%) and shortness of breath (34.8%) was reported at baseline with substantial reduction in their frequency at subsequent follow-up visits. These symptoms virtually disappeared very quickly in both quitters and reducers. Smokers invited to switch to electronic cigarettes who completely abstained from smoking showed steady progressive improvements in their FEF25-75% Normalization of peripheral airways function was associated with improvement in respiratory symptoms, adding to the notion that abstaining from smoking can reverse tobacco harm in the lung.

Concepts: Pulmonology, Smoking, Tobacco, Cigarette, Nicotine, Smoking cessation, Electronic cigarette, Spirometry

4

Although weight loss can usually be achieved by restricting food intake, the majority of dieters regain weight over the long-term. In the hypothalamus, hormonal signals from the gastrointestinal tract, adipose tissue and other peripheral sites are integrated to influence appetite and energy expenditure. Diet-induced weight loss is accompanied by several physiological changes which encourage weight regain, including alterations in energy expenditure, substrate metabolism and hormone pathways involved in appetite regulation, many of which persist beyond the initial weight loss period. Safe effective long-term strategies to overcome these physiological changes are needed to help facilitate maintenance of weight loss. The present review, which focuses on data from human studies, begins with an outline of body weight regulation to provide the context for the subsequent discussion of short- and long-term physiological changes which accompany diet-induced weight loss.

Concepts: Metabolism, Nutrition, Obesity, Weight loss, Dieting, Puberty, Appetite, Leptin

3

Data showing a remarkable gender difference in life expectancy and mortality, including survival to extreme age, are reviewed starting from clinical and demographic data and stressing the importance of a comprehensive historical perspective and a gene-environment/lifestyle interaction. Gender difference regarding prevalence and incidence of the most important age-related diseases, such as cardiovascular and neurodegenerative diseases, cancer, Type 2 diabetes, disability, autoimmunity and infections, are reviewed and updated with particular attention to the role of the immune system and immunosenescence. On the whole, gender differences appear to be pervasive and still poorly considered and investigated despite their biomedical relevance. The basic biological mechanisms responsible for gender differences in aging and longevity are quite complex and still poorly understood. The present review focuses on centenarians and their offspring as a model of healthy aging and summarizes available knowledge on three basic biological phenomena, i.e. age-related X chromosome inactivation skewing, gut microbiome changes and maternally inherited mitochondrial DNA genetic variants. In conclusion, an appropriate gender-specific medicine approach is urgently needed and should be systematically pursued in studies on healthy aging, longevity and age-related diseases, in a globalized world characterized by great gender differences which have a high impact on health and diseases.

Concepts: Immune system, DNA, Medicine, Genetics, Epidemiology, Demography, Population, X-inactivation