19 research outputs found

    Evolution of ligand specificity in vertebrate corticosteroid receptors

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    <p>Abstract</p> <p>Background</p> <p>Corticosteroid receptors include mineralocorticoid (MR) and glucocorticoid (GR) receptors. Teleost fishes have a single MR and duplicate GRs that show variable sensitivities to mineralocorticoids and glucocorticoids. How these receptors compare functionally to tetrapod MR and GR, and the evolutionary significance of maintaining two GRs, remains unclear.</p> <p>Results</p> <p>We used up to seven steroids (including aldosterone, cortisol and 11-deoxycorticosterone [DOC]) to compare the ligand specificity of the ligand binding domains of corticosteroid receptors between a mammal (<it>Mus musculus</it>) and the midshipman fish (<it>Porichthys notatus</it>), a teleost model for steroid regulation of neural and behavioral plasticity. Variation in mineralocorticoid sensitivity was considered in a broader phylogenetic context by examining the aldosterone sensitivity of MR and GRs from the distantly related daffodil cichlid (<it>Neolamprologus pulcher</it>), another teleost model for neurobehavioral plasticity. Both teleost species had a single MR and duplicate GRs. All MRs were sensitive to DOC, consistent with the hypothesis that DOC was the initial ligand of the ancestral MR. Variation in GR steroid-specificity corresponds to nine identified amino acid residue substitutions rather than phylogenetic relationships based on receptor sequences.</p> <p>Conclusion</p> <p>The mineralocorticoid sensitivity of duplicate GRs in teleosts is highly labile in the context of their evolutionary phylogeny, a property that likely led to neo-functionalization and maintenance of two GRs.</p

    Androgen replacement therapy improves function in male rat muscles independently of hypertrophy and activation of the Akt/mTOR pathway

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    AIM: We analysed the effect of physiological doses of androgens following orchidectomy on skeletal muscle and bone of male rats, as well as the relationships between muscle performance, hypertrophy and the Akt/mammalian target of rapamycin (mTOR) signalling pathway involved in the control of anabolic and catabolic muscle metabolism. METHODS: We studied the soleus muscle and tibia from intact rats (SHAM), orchidectomized rats treated for 3 months with vehicle (ORX), nandrolone decanoate (NAN) or dihydrotestosterone (DHT). RESULTS: Orchidectomy had very little effect on the soleus muscle. However, maximal force production by soleus muscle (+69%) and fatigue resistance (+35%) in NAN rats were both increased when compared with ORX rats. In contrast, DHT treatment did not improve muscle function. The relative number of muscle fibres expressing slow myosin heavy chain and citrate synthase activity were not different in NAN and ORX rats. Moreover, NAN and DHT treatments did not modify muscle weights and cross-sectional area of muscle fibres. Furthermore, phosphorylation levels of downstream targets of the Akt/mTOR signalling pathway, Akt, ribosomal protein S6 and eukaryotic initiation factor 4E-binding protein 1 were similar in muscles of NAN, DHT and ORX rats. In addition, trabecular tibia from NAN and DHT rats displayed higher bone mineral density and bone volume when compared with ORX rats. Only in NAN rats was this associated with increased bone resistance to fracture. CONCLUSION: Physiological doses of androgens are beneficial to muscle performance in orchidectomized rats without relationship to muscle and fibre hypertrophy and activation of the Akt/mTOR signalling pathway. Taken together our data clearly indicate that the activity of androgens on muscle and bone could participate in the global improvement of musculoskeletal status in the context of androgen deprivation induced by ageing

    Dupilumab efficacy in uncontrolled, moderate-to-severe asthma with self-reported chronic rhinosinusitis

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    Background Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin (IL)-4 and IL-13 signaling, key drivers of type 2 inflammation. In the phase 3 study (NCT02414854), add-on dupilumab 200mg/300mg every 2 weeks, versus placebo, significantly reduced severe asthma exacerbations and improved pre-bronchodilator forced expiratory volume in 1 second (FEV1) and quality-of-life measures in patients with uncontrolled, moderate-to-severe asthma, with greater efficacy observed in those with a high baseline type 2 phenotype. Objective To assess the efficacy and safety of dupilumab in uncontrolled, moderate-to-severe asthma patients with or without self-reported comorbid chronic rhinosinusitis (CRS or non-CRS). Methods Comorbid CRS was self-reported by patients using an e-diary. Annualized severe exacerbation rates, changes from baseline in pre- and post-bronchodilator FEV1, patient-reported outcomes, type 2 biomarkers, and safety were assessed. Results CRS was self-reported by 382/1902 (20.1%) patients. Dupilumab 200mg/300mg reduced annualized severe exacerbation rates by 63%/61%, respectively, in patients with CRS, and by 42%/40% in patients without CRS (all P≺.001 vs placebo). Dupilumab also improved lung function and patient-reported asthma control and quality of life, and suppressed type 2 biomarkers versus placebo in both subgroups. Clinical responses were rapid, with near-maximal responses observed at the earliest measured timepoints and sustained at week 52. Improvements observed in the CRS subgroup were similar to or numerically greater than those in the non-CRS subgroup. Conclusion Dupilumab showed efficacy and was generally well tolerated in patients with uncontrolled, moderate-to-severe asthma with or without CRS.</p

    Dupilumab efficacy in uncontrolled, moderate-to-severe asthma with self-reported chronic rhinosinusitis

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    Background Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for IL-4 and IL-13 signaling, key drivers of type 2 inflammation. In the phase 3 study (NCT02414854), add-on dupilumab 200 mg/300 mg every 2 weeks, versus placebo, significantly reduced severe asthma exacerbations and improved pre-bronchodilator forced expiratory volume in 1 second (FEV1) and quality-of-life measures in patients with uncontrolled, moderate-to-severe asthma, with greater efficacy observed in those with a high baseline type 2 phenotype. Objective To assess the efficacy and safety of dupilumab in patients with uncontrolled, moderate-to-severe asthma with or without self-reported comorbid chronic rhinosinusitis (CRS or non-CRS). Methods Comorbid CRS was self-reported by patients using an e-diary. Annualized severe exacerbation rates, changes from baseline in pre- and post-bronchodilator FEV1, patient-reported outcomes, type 2 biomarkers, and safety were assessed. Results CRS was self-reported by 382 of 1902 (20.1%) patients. Dupilumab 200 mg/300 mg reduced annualized severe exacerbation rates by 63%/61%, respectively, in patients with CRS, and by 42%/40% in patients without CRS (all P Conclusion Dupilumab showed efficacy and was generally well tolerated in patients with uncontrolled, moderate-to-severe asthma with or without CRS.</p

    Dupilumab efficacy in patients with uncontrolled, moderate-to-severe allergic asthma

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    BACKGROUND: Dupilumab blocks the shared receptor component for IL-4 and IL-13, key drivers of type 2 inflammation, including IgE-mediated allergic inflammation in asthma. In the LIBERTY ASTHMA QUEST (NCT02414854) study, dupilumab reduced severe asthma exacerbations and improved forced expiratory volume in 1 second (FEV1) in patients with uncontrolled, moderate-to-severe asthma with greater efficacy observed in patients with elevated type 2 inflammatory biomarkers (blood eosinophils and fractional exhaled nitric oxide) at baseline. OBJECTIVE: We assessed dupilumab's effect on key asthma outcomes in QUEST patients with/without evidence of allergic patients with uncontrolled, moderate-to-severe asthma with greater efficacy observed in patients with elevated type 2 inflammatory biomarkers (blood eosinophils and fractional exhaled nitric oxide) at baseline. OBJECTIVE: We assessed dupilumab's effect on key asthma outcomes in QUEST patients with/without evidence of allergic asthma (total serum IgE >= 30 IU/mL and >= 1 perennial aeroallergen-specific IgE >= 0.35 kU/L at baseline). METHODS: Severe exacerbation rates and change from baseline in FEV1, asthma control, and markers of type 2 inflammation during the 52-week treatment period were assessed. RESULTS: In the allergic asthma subgroup (n = 1083), dupilumab 200/300 mg every 2 weeks versus placebo reduced severe asthma exacerbation rates (-36.9%/-45.5%; both P < .01), improved FEV1 at week 12 (0.13 L/0.16 L; both P < .001; improvements were evident by the first evaluation at week 2) with greater efficacy observed in patients with elevated type 2 inflammatory biomarkers at baseline, and improved asthma control. Dupilumab treatment also resulted in rapid and sustained reductions in type 2 inflammatory biomarkers. Comparable results were observed in patients without evidence of allergic asthma (n = 819). CONCLUSION: Dupilumab reduced severe exacerbation rates, improved FEV1 and asthma control, and suppressed type 2 inflammatory biomarkers in patients with uncontrolled, moderate-to-severe asthma with or without evidence of allergic asthma, highlighting the key role of IL-4 and IL-13 in airway inflammation. (C) 2019 The Authors. Published by Elsevier Inc. on behalf of the American Academy of Allergy, Asthma & Immunolog

    Efficacy of dupilumab on clinical outcomes in patients with asthma and perennial allergic rhinitis

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    Background: Comorbid perennial allergic rhinitis (PAR) or year-round aeroallergen sensitivity substantially contributes to disease burden in patients with asthma. Dupilumab blocks the shared receptor for interleukin (IL) 4 and IL-13, key drivers of type 2 inflammation that play important roles in asthma and PAR. In the LIBERTY ASTHMA QUEST trial (NCT02414854), dupilumab reduced severe asthma exacerbations and improved forced expiratory volume in 1 second (FEV1) in patients with uncontrolled, moderate-to-severe asthma, with greater efficacy observed in patients with elevated type 2 inflammatory biomarkers at baseline (blood eosinophils and fractional exhaled nitric oxide). Objective: To assess dupilumab efficacy in LIBERTY ASTHMA QUEST patients with comorbid PAR. Methods: Severe asthma exacerbation rates, FEV1, asthma control (5-item Asthma Control Questionnaire), rhinoconjunctivitis-specific health-related quality of life (Standardized Rhinoconjunctivitis Quality of Life Questionnaire +12 scores), and type 2 inflammatory biomarkers during the 52-week treatment period were assessed. Results: A total of 814 of the 1902 patients (42.8%) had comorbid PAR (defined as an allergic rhinitis history and ≥1 perennial aeroallergen specific immunoglobulin E (IgE) level ≥0.35 kU/L at baseline). Dupilumab, 200 and 300 mg every 2 weeks, vs placebo reduced severe exacerbations rates by 32.2% and 34.6% (P &lt;.05 for both) and improved FEV1 at week 12 by 0.14 L and 0.18 L (P &lt;.01 for both); greater efficacy was observed in patients with elevated baseline blood eosinophil counts (≥300 cells/μL) and fractional exhaled nitric oxide. Dupilumab treatment also numerically improved the 5-item Asthma Control Questionnaire and Standardized Rhinoconjunctivitis Quality of Life Questionnaire +12 scores and suppressed type 2 inflammatory biomarkers. Conclusion: Dupilumab improved key asthma-related outcomes, asthma control, and rhinoconjunctivitis-specific health-related quality of life while suppressing type 2 inflammatory biomarkers and perennial allergen-specific IgE in patients with moderate-to-severe asthma and comorbid PAR, highlighting its dual inhibitory effects on IL-4 and IL-13 and its role in managing asthma and PAR
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