Dataset Information

Role of Differential Estrogen Receptor Activation in Airway Hyperreactivity and Remodeling in a Murine Model of Asthma.

ABSTRACT: Evidence suggests that airway hyperresponsiveness (AHR) is a characteristic feature of asthma. Epidemiological studies have confirmed that the severity of asthma is greater in women, suggesting a critical role of female sex steroid hormones (especially estrogen). Very few in vivo studies have examined the role of sex steroid hormones in asthma, and the sequence of events that occur through differential activation of estrogen receptors (ERs) remains to be determined in asthmatic airways. Our recent in vitro findings indicated that ERβ had increased expression in asthmatic airway smooth muscle (ASM), and that its activation by an ERβ-specific agonist downregulated airway remodeling. In this study, we translated the in vitro findings to a murine asthma model and examined the differential role of ER activation in modulating lung mechanics. C57BL/6J male, female, and ovariectomized mice were exposed to mixed allergen (MA) and subcutaneously implanted with sustained-release pellets of placebo, an ERα agonist (4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol [PPT]), and/or an ERβ agonist (WAY-200070). We then evaluated the effects of these treatments on airway mechanics, biochemical, molecular, and histological parameters. Mice exposed to MA showed a significant increase in airway resistance, elastance, and tissue damping, and a decrease in compliance; pronounced effects were observed in females. Compared with PPT, WAY treatment significantly reversed the MA-induced changes. The increased mRNA/protein expression of ERα, ERβ, and remodeling genes observed in MA-treated mice was significantly reversed in WAY-treated mice. This novel study indicates that activation of ERβ signaling downregulates AHR and airway remodeling, and is a promising target in the development of treatments for asthma.

SUBMITTER: Ambhore NS

PROVIDER: S-EPMC6775953 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Epidemiological data suggests increased prevalence of asthma in females than males, suggesting a plausible role for sex-steroids, especially estrogen in the lungs. Estrogen primarily acts through estrogen-receptors (ER? and ER?), which play a differential role in asthma. Our previous studies demonstrated increased expression of ER? in asthmatic human airway smooth muscle (ASM) cells and its activation diminished ASM proliferation in vitro and airway hyperresponsiveness (AHR) in vivo in a mouse (wild-type, WT) model of asthma. In this study, we evaluated the receptor specific effect of circulating endogenous estrogen in regulating AHR and remodeling using ER? and ER? knockout (KO) mice. C57BL/6J WT, ER? KO, and ER? KO mice were challenged intranasally with a mixed-allergen (MA) or PBS. Lung function was measured using flexiVent followed by collection of broncho-alveolar lavage fluid for differential leukocyte count (DLC), histology using hematoxylin and eosin (H&E) and Sirius red-fast green (SRFG) and detecting ?smooth muscle actin (?-SMA), fibronectin and vimentin expression using immunofluorescence (IF). Resistance (Rrs), elastance (Ers), tissue-damping (G) and tissue-elasticity (H) were significantly increased, whereas compliance (Crs) was significantly decreased in WT, ER? KO, and ER? KO mice (males and females) challenged with MA compared to PBS. Interestingly, ER? KO mice showed declined lung function compared to ER? KO and WT mice at baseline. MA induced AHR, remodeling and immune-cell infiltration was more prominent in females compared to males across all populations, while ER? KO females showed maximum AHR and DLC, except for neutrophil count. Histology using H&E suggests increased smooth muscle mass in airways with recruitment of inflammatory cells, while SRFG staining showed increased collagen deposition in MA challenged ER? KO mice compared to ER? KO and WT mice (males and females), with pronounced effects in ER? KO females. Furthermore, IF studies showed increased expression of ?-SMA, fibronectin and vimentin in MA challenged populations compared to PBS, with prominent changes in ER? KO females. This novel study indicates ER? plays a pivotal role in airway remodeling and AHR and understanding the mechanisms involved might help to surface it out as a potential target to treat asthma.

Project description:Background:Purinergic receptors control cell proliferation, apoptosis, migration, inflammation, and cytokine secretion. Increased expression of specific purinergic receptors is reported in asthma. The role of purinergic P2Y6 receptors (P2Y6R) in asthma is controversial. Hypothesis:P2Y6R activation in asthma improves pulmonary function and reduces inflammation and smooth muscle amount. Methods:Female mice (C57/BL6, age 30 days) were randomly assigned to receive intranasal house dust mite (HDM) antigen (40 or 80 µg) or saline, 5 days/week, for 6 weeks. Randomly selected subgroups received intraperitoneal P2Y6R agonist prodrug (GC021109; 10 or 100 µg/kg weight/dose) simultaneously with HDM. After 6 weeks, lung function was measured. Lung lavage fluid (LLF) was used to measure total cell count, total protein, and cytokines. Immunohistochemistry for alpha smooth muscle actin (?-SMA) was done. Airway wall thickness was measured on micro-computed tomography (micro-CT) images. Results:Pulmonary function testing revealed a HDM dose-dependent airway hyperresponsiveness. Airway resistance was increased 2-fold while compliance was decreased by 50% at the higher HDM dose (P<0.05). GC021109 prevented these changes. HDM-exposed mice had elevated inflammatory cell and total protein levels in LLF which were prevented by GC021109 (P<0.05). HDM mice also had elevated LLF levels of interleukin (IL)-4, IL-5, IL-12, granulocyte colony stimulating factor, chemokine (C-X-C) motif ligand 1, and leukemia inhibitory factor that were reduced by GC021109 with a dose-dependent pattern. HDM mice had increased peribronchial and perivascular inflammatory cell infiltration and increased ?-SMA; these changes were absent with GC021109. Airway wall thickness measured on micro-CT images was increased after HDM exposure and significantly reduced by GC021109 treatment. Conclusion:The P2Y6R prodrug GC021109 inhibited allergen-induced changes in pulmonary function, inflammatory responses, and airway and vascular smooth muscle mass. P2Y6R activation may be an effective therapeutic maintenance strategy in asthma.

Project description:Altered airway smooth muscle (ASM) mass and extracellular matrix (ECM) deposition in airways are characteristic features of remodeling in asthma. Increased ECM production modulates ASM cell proliferation and leads to airway remodeling. Our previous studies showed that ASM from patients with asthma exhibited increased expression of estrogen receptor (ER)-?, which upon activation down-regulated ASM proliferation, implicating an important role for estrogen signaling in airway physiology. There is no current information on the effect of differential ER activation on ECM production. In this study, we evaluated the effect of ER-? vs. ER-? activation on ECM production, deposition, and underlying pathways. Primary human ASM cells isolated from asthmatics and nonasthmatics were treated with E2, an ER-? agonist [propylpyrazoletriol (PPT)], and an ER-? agonist [WAY-200070 (WAY)] with TNF-? or platelet-derived growth factor (PDGF) followed by evaluation of ECM production and deposition. Expression of proteins and genes corresponding to ECM were measured using Western blotting and quantitative RT-PCR with subsequent matrix metalloproteinase (MMP) activity. Molecular mechanisms of ER activation in regulating ECM were evaluated by luciferase reporter assays for activator protein 1 (AP-1) and NF-?B. TNF-? or PDGF significantly (P < 0.001) increased ECM deposition and MMP activity in human ASM cells, which was significantly reduced with WAY treatment but not with PPT. Furthermore, TNF-?- or PDGF-induced ECM gene expression in ASM cells was significantly reduced with WAY (P < 0.001). Moreover, WAY significantly down-regulated the activation of NF-?B (P < 0.001) and AP-1 (P < 0.01, P < 0.05) in ASM cells from asthmatics and nonasthmatics. Overall, we demonstrate differential ER signaling in controlling ECM production and deposition. Activation of ER-? diminishes ECM deposition via suppressing the NF-?B pathway activity and might serve as a novel target to blunt airway remodeling.-Ambhore, N. S., Kalidhindi, R. S. R., Pabelick, C. M., Hawse, J. R., Prakash, Y. S., Sathish, V. Differential estrogen-receptor activation regulates extracellular matrix deposition in human airway smooth muscle remodeling via NF-?B pathway.

Dataset Information

Role of Differential Estrogen Receptor Activation in Airway Hyperreactivity and Remodeling in a Murine Model of Asthma.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets