Spontaneous airway hyperresponsiveness in estrogen receptor-alpha-deficient mice.
Ontology highlight
ABSTRACT: Rationale
Airway hyperresponsiveness is a critical feature of asthma. Substantial epidemiologic evidence supports a role for female sex hormones in modulating lung function and airway hyperresponsiveness in humans.Objectives
To examine the role of estrogen receptors in modulating lung function and airway responsiveness using estrogen receptor-deficient mice.Methods
Lung function was assessed by a combination of whole-body barometric plethysmography, invasive measurement of airway resistance, and isometric force measurements in isolated bronchial rings. M2 muscarinic receptor expression was assessed by Western blotting, and function was assessed by electrical field stimulation of tracheas in the presence/absence of gallamine. Allergic airway disease was examined after ovalbumin sensitization and exposure.Measurements and main results
Estrogen receptor-alpha knockout mice exhibit a variety of lung function abnormalities and have enhanced airway responsiveness to inhaled methacholine and serotonin under basal conditions. This is associated with reduced M2 muscarinic receptor expression and function in the lungs. Absence of estrogen receptor-alpha also leads to increased airway responsiveness without increased inflammation after allergen sensitization and challenge.Conclusions
These data suggest that estrogen receptor-alpha is a critical regulator of airway hyperresponsiveness in mice.
SUBMITTER: Carey MA
PROVIDER: S-EPMC1899278 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Progranulin (PGRN) is a multifunctional growth factor with functions in neuroprotection, anti-inflammation, and neural progenitor cell proliferation. These functions largely overlap with the actions of estrogen in the brain. Indeed, we have previously shown that PGRN mediates the functions of estrogen, such as masculinizing the rodent brain and promoting adult neurogenesis. To evaluate the underlying mechanism of PGRN in mediating the actions of estrogen, the localization of estrogen receptor α (ERα) in the brains of wild-type (WT) and PGRN-deficient (KO) mice was investigated. First, double-labeling immunofluorescence was performed for ERα with neuronal nuclei (NeuN), ionized calcium-binding adaptor molecule 1 (Iba1), and glial fibrillary acidic protein (GFAP), as markers for neurons, microglia, and astrocytes, respectively, in female mice in diestrous and estrous stages. ERα-immunoreactive (IR) cells were widespread and co-localized with NeuN in brain sections analyzed (bregma -1.06 to -3.16 mm) of both WT and KO mice. In contrast, expression of ERα was not observed in Iba1-IR cells from both genotypes. Interestingly, although ERα was co-localized with GFAP in WT mice, virtually no ERα expression was discernible in GFAP-IR cells in KO mice. Next, the brains of ovariectomized adult female, adult male, and immature female mice were subjected to immunostaining for ERα and GFAP. Again, co-localization of ERα with GFAP was observed in WT mice, whereas this co-localization was not detected in KO mice. These results suggest that PGRN plays a crucial role in the expression of ERα in astrocytes regardless of the estrous cycle stage, sex, and maturity.
| S-EPMC5177971 | biostudies-literature
Project description:IntroductionAlthough breast cancers expressing estrogen receptor-α (ERα) and progesterone receptors (PR) are the most common form of mammary malignancy in humans, it has been difficult to develop a suitable mouse model showing similar steroid hormone responsiveness. STAT transcription factors play critical roles in mammary gland tumorigenesis, but the precise role of STAT1 remains unclear. Herein, we show that a subset of human breast cancers display reduced STAT1 expression and that mice lacking STAT1 surprisingly develop ERα+/PR+ mammary tumors.MethodsWe used a combination of approaches, including histological examination, gene targeted mice, gene expression analysis, tumor transplantaion, and immunophenotyping, to pursue this study.ResultsForty-five percent (37/83) of human ERα+ and 22% (17/78) of ERα- breast cancers display undetectable or low levels of STAT1 expression in neoplastic cells. In contrast, STAT1 expression is elevated in epithelial cells of normal breast tissues adjacent to the malignant lesions, suggesting that STAT1 is selectively downregulated in the tumor cells during tumor progression. Interestingly, the expression levels of STAT1 in the tumor-infiltrating stromal cells remain elevated, indicating that single-cell resolution analysis of STAT1 level in primary breast cancer biopsies is necessary for accurate assessment. Female mice lacking functional STAT1 spontaneously develop mammary adenocarcinomas that comprise > 90% ERα+/PR+ tumor cells, and depend on estrogen for tumor engraftment and progression. Phenotypic marker analyses demonstrate that STAT1-/- mammary tumors arise from luminal epithelial cells, but not myoepithelial cells. In addition, the molecular signature of the STAT1-/- mammary tumors overlaps closely to that of human luminal breast cancers. Finally, introduction of wildtype STAT1, but not a STAT1 mutant lacking the critical Tyr701 residue, into STAT1-/- mammary tumor cells results in apoptosis, demonstrating that the tumor suppressor function of STAT1 is cell-autonomous and requires its transcriptional activity.ConclusionsOur findings demonstrate that STAT1 suppresses mammary tumor formation and its expression is frequently lost during breast cancer progression. Spontaneous mammary tumors that develop in STAT1-/- mice closely recapitulate the progression, ovarian hormone responsiveness, and molecular characteristics of human luminal breast cancer, the most common subtype of human breast neoplasms, and thus represent a valuable platform for testing novel treatments and detection modalities.
| S-EPMC3496133 | biostudies-literature
Project description:ContextStigmasterol has significant anti-arthritis and anti-inflammatory effects, but its role in immune and inflammatory diseases is still unclear.ObjectiveThe potential advantages of stigmasterol in asthma were explored in IL-13-induced BEAS-2B cells and asthmatic mice.Materials and methodsThe optimal target of stigmasterol was confirmed in asthma. After detecting the cytotoxicity of stigmasterol in BEAS-2B cells, 10 μg/mL and 20 μg/mL stigmasterol were incubated with the BEAS-2B cell model for 48 h, and anti-inflammation and antioxidative stress were verified. Asthmatic mice were induced by OVA and received 100 mg/kg stigmasterol for 7 consecutive days. After 28 days, lung tissues and BAL fluid were collected for the following study. To further verify the role of NK1-R, 0.1 μM WIN62577 (NK1-R specific antagonist), and 1 μM recombinant human NK1-R protein were applied.ResultsNK1-R was the potential target of stigmasterol. When the concentration of stigmasterol is 20 μg/mL, the survival rate of BEAS-2B cells is about 98.4%, which is non-toxic. Stigmasterol exerted anti-inflammation and antioxidant stress in a dose-dependent manner and decreased NK1-R expression in IL-13-induced BEAS-2B. Meanwhile, in vivo assay also indicated the anti-inflammation and antioxidant stress of stigmasterol after OVA challenge. Stigmasterol inhibited inflammation infiltration and mucus hypersecretion, and NK1-R expression.Discussion and conclusionsThe protective effect of stigmaterol on asthma and its underlying mechanism have been discussed in depth, providing a theoretical basis and more possibilities for its treatment of asthma.
| S-EPMC9930798 | biostudies-literature
Project description:Estrogen is atheroprotective and a high-affinity ligand for both known estrogen receptors, ERalpha and ERbeta. However, the role of the ERalpha in early-stage atherosclerosis has not been directly investigated and is incompletely understood. ERalpha-deficient (ERalpha-/-) and wild-type (ERalpha+/+) female mice consuming an atherogenic diet were studied concurrent with estrogen replacement to distinguish the actions of 17beta-estradiol (E(2)) from those of ERalpha on the development of early atherosclerotic lesions. Mice were ovariectomized and implanted with subcutaneous slow-release pellets designed to deliver 6 or 8 mug/day of exogenous 17beta-estradiol (E(2)) for a period of up to 4 months. Ovariectomized mice (OVX) with placebo pellets (E(2)-deficient controls) were compared to mice with endogenous E(2) (intact ovaries) and exogenous E(2). Aortas were analyzed for lesion area, number, and distribution. Lipid and hormone levels were also determined. Compared to OVX, early lesion development was significantly (p < 0.001) attenuated by E(2) with 55-64% reduction in lesion area by endogenous E(2) and >90% reduction by exogenous E(2). Compared to OVX, a decline in lesion number (2- to 4-fold) and lesser predilection (~4-fold) of lesion formation in the proximal aorta also occurred with E(2). Lesion size, development, number, and distribution inversely correlated with circulating plasma E(2) levels. However, atheroprotection was independent of ERalpha status, and E(2) athero-protection in both genotypes was not explained by changes in plasma lipid levels (total cholesterol, triglyceride, and high-density lipoprotein cholesterol). The ERalpha is not essential for endogenous/exogenous E(2)-mediated protection against early-stage atherosclerosis. These observations have potentially significant implications for understanding the molecular and cellular mechanisms and timing of estrogen action in different estrogen receptor (ER) deletion murine models of atherosclerosis, as well as implications to human studies of ER polymorphisms and lipid metabolism. Our findings may contribute to future improved clinical decision-making concerning the use of hormone therapy.
| S-EPMC2719738 | biostudies-other
Project description:Patients with severe, treatment-refractory asthma are at risk for death from acute exacerbations. The cytokine IL17A has been associated with airway inflammation in severe asthma, and novel therapeutic targets within this pathway are urgently needed. We recently showed that IL17A increases airway contractility by activating the procontractile GTPase RhoA. Here, we explore the therapeutic potential of targeting the RhoA pathway activated by IL17A by inhibiting RhoA guanine nucleotide exchange factors (RhoGEFs), intracellular activators of RhoA. We first used a ribosomal pulldown approach to profile mouse airway smooth muscle by qPCR and identified Arhgef12 as highly expressed among a panel of RhoGEFs. ARHGEF12 was also the most highly expressed RhoGEF in patients with asthma, as found by RNA sequencing. Tracheal rings from Arhgef12-KO mice and WT rings treated with a RhoGEF inhibitor had evidence of decreased contractility and RhoA activation in response to IL17A treatment. In a house dust mite model of allergic sensitization, Arhgef12-KO mice had decreased airway hyperresponsiveness without effects on airway inflammation. Taken together, our results show that Arhgef12 is necessary for IL17A-induced airway contractility and identify a therapeutic target for severe asthma.
| S-EPMC6238747 | biostudies-literature
Project description:RationaleAllergically inflamed mice exhibit airway hyperresponsiveness to inhaled methacholine, which computer simulations of lung impedance suggest is due to enhanced lung derecruitment and which we sought to verify in the present study.MethodsBALB/c mice were sensitized and challenged with ovalbumin to induce allergic inflammation; the control mice were sensitized but received no challenge. The mice were then challenged with inhaled methacholine and respiratory system impedance tracked for the following 10 minutes. Respiratory elastance (H) was estimated from each impedance measurement. One group of mice was ventilated with 100% O(2) during this procedure and another group was ventilated with air. After the procedure, the mice were killed and ventilated with pure N(2), after which the trachea was tied off and the lungs were imaged with micro-computed tomography (micro-CT).ResultsH was significantly higher in allergic mice than in control animals after methacholine challenge. The ratio of H at the end of the measurement period between allergic and nonallergic mice ventilated with O(2) was 1.36, indicating substantial derecruitment in the allergic animals. The ratio between lung volumes determined by micro-CT in the control and the allergic mice was also 1.36, indicative of a corresponding volume loss due to absorption atelectasis. Micro-CT images and histograms of Hounsfield units from the lungs also showed increased volume loss in the allergic mice compared with control animals after methacholine challenge.ConclusionsThese results support the conclusion that airway closure is a major component of hyperresponsiveness in allergically inflamed mice.
| S-EPMC1899295 | biostudies-literature
Project description:Gata5 is a transcription factor expressed in the lung, but its physiological role is unknown. To test whether and how Gata5 regulates airway constrictor responsiveness, we studied Gata5(-/-), Gata5(+/-), and wild-type mice on the C57BL/6J background. Cholinergic airway constrictor responsiveness was assessed invasively in mice without and with induction of allergic airway inflammation through ovalbumin sensitization and aerosol exposure. Gata5-deficient mice displayed native airway constrictor hyperresponsiveness (AHR) in the absence of allergen-induced inflammation. Gata5-deficient mice retained their relatively greater constrictor responsiveness even in ovalbumin-induced experimental asthma. Gata5 deficiency did not alter the distribution of cell types in bronchoalveolar lavage fluid, but bronchial epithelial mucus metaplasia was more prominent in Gata5(-/-) mice after allergen challenge. Gene expression profiles revealed that apolipoprotein E (apoE) was the fifth most down-regulated transcript in Gata5-deficient lungs, and quantitative RT-PCR and immunostaining confirmed reduced apoE expression in Gata5(-/-) mice. Quantitative RT-PCR also revealed increased IL-13 mRNA in the lungs of Gata5-deficient mice. These findings for the first time show that Gata5 regulates apoE and IL-13 expression in vivo and that its deletion causes AHR. Gata5-deficient mice exhibit an airway phenotype that closely resembles that previously reported for apoE(-/-) mice: both exhibit cholinergic AHR in native and experimental asthma states, and there is excessive goblet cell metaplasia after allergen sensitization and challenge. The Gata5-deficient phenotype also shares features that were previously reported for IL-13-treated mice. Together, these results indicate that Gata5 deficiency induces AHR, at least in part, by blunting apoE and increasing IL-13 expression.
| S-EPMC4068924 | biostudies-literature
Project description:Production of the cytokines IL-4 and IL-13 is increased in both human asthma and mouse asthma models, and Stat6 activation by the common IL-4/IL-13R drives most mouse model pathophysiology, including airway hyperresponsiveness (AHR). However, the precise cellular mechanisms through which IL-4R? induces AHR remain unclear. Overzealous bronchial smooth muscle constriction is thought to underlie AHR in human asthma, but the smooth muscle contribution to AHR has never been directly assessed. Furthermore, differences in mouse versus human airway anatomy and observations that selective IL-13 stimulation of Stat6 in airway epithelium induces murine AHR raise questions about the importance of direct IL-4R effects on smooth muscle in murine asthma models and the relevance of these models to human asthma. Using transgenic mice in which smooth muscle is the only cell type that expresses or fails to express IL-4R?, we demonstrate that direct smooth muscle activation by IL-4, IL-13, or allergen is sufficient but not necessary to induce AHR. Five genes known to promote smooth muscle migration, proliferation, and contractility are activated by IL-13 in smooth muscle in vivo. These observations demonstrate that IL-4R? promotes AHR through multiple mechanisms and provide a model for testing smooth muscle-directed asthma therapeutics.
| S-EPMC3135339 | biostudies-literature
Project description:The experiment was conducted to examine the effect of a high fat diet (HFD) on airway hyperresponsiveness (AHR) in mice. Twenty-three adult male C57BL/6?J mice were fed with HFD or regular chow diet for two weeks. The total respiratory resistance was measured by forced oscillation technique at baseline and after methacholine aerosol challenge at 1, 3, 10 and 30?mg/mL. Bronchoalveolar lavage (BAL) was performed. Lipid levels and lipid peroxidation in lung tissue were measured along with gene expression of multiple cytokines. Lungs were digested, and IL-1? secretion by pulmonary macrophages was determined. HFD feeding resulted in 11% higher body weight compared to chow. HFD did not affect respiratory resistance at baseline, but significantly augmented airway responses to methacholine compared to chow diet (40.5?±?17.7% increase at 30?mg/ml methacholine, p?<?0.05). HFD induced a 3.2?±?0.6 fold increase in IL-1? gene expression (p?<?0.001) and a 38 fold increase in IL-1? secretion in the lungs. There was no change in BAL and no change in any other cytokines, lipid levels or lipid peroxidation. Hence, HFD induced AHR in mice prior to the development of significant obesity which was associated with up-regulation of pulmonary IL-1?.
| S-EPMC5913253 | biostudies-other
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.
| S-EPMC7010956 | biostudies-literature