icg-001 and Asthma

Aberrant activation of β-catenin signaling by both WNT-dependent and WNT-independent pathways has been demonstrated in asthmatic airways, which is thought to contribute critically in remodeling of the airways. Yet, the exact role of β-catenin in asthma is very poorly defined. As we have previously reported abnormal expression of β-catenin in a toluene diisocyanate (TDI)-induced asthma model, in this study, we evaluated the therapeutic efficacy of two small molecules XAV-939 and ICG-001 in TDI-asthmatic male BALB/c mice, which selectively block β-catenin-mediated transcription.. Male BALB/c mice were sensitized and challenged with TDI to generate a chemically induced asthma model. Inhibitors of β-catenin, XAV-939, and ICG-001 were respectively given to the mice through intraperitoneally injection.. TDI exposure led to a significantly increased activity of β-catenin, which was then confirmed by a luciferase assay in 16HBE transfected with the TOPFlash reporter plasmid. Treatment with either XAV-939 or ICG-001 effectively inhibited activation of β-catenin and downregulated mRNA expression of β-catenin-targeted genes in TDI-asthmatic mice, paralleled by dramatically attenuated TDI-induced hyperresponsiveness and inflammation of the airway, alleviated airway goblet cell metaplasia and collagen deposition, decreased Th2 inflammation, as well as lower levels of TGFβ1, VEGF, HMGB1, and IL-1β.. The results showed that β-catenin is a principal mediator of TDI-induced asthma, proposing β-catenin as a promising therapeutic target in asthma.

Topics: Airway Remodeling; Animals; Anti-Asthmatic Agents; Asthma; beta Catenin; Biomarkers; Bridged Bicyclo Compounds, Heterocyclic; Bronchoalveolar Lavage Fluid; Disease Models, Animal; Gene Expression Regulation; Heterocyclic Compounds, 3-Ring; Immunoglobulin E; Immunohistochemistry; Lymphocytes; Male; Mice; Molecular Targeted Therapy; Pyrimidinones; Signal Transduction; Toluene 2,4-Diisocyanate

Asthma is a heterogeneous chronic inflammatory disease, characterized by the development of structural changes (airway remodelling). β-catenin, a transcriptional co-activator, is fundamentally involved in airway smooth muscle growth and may be a potential target in the treatment of airway smooth muscle remodelling.. We assessed the ability of small-molecule compounds that selectively target β-catenin breakdown or its interactions with transcriptional co-activators to inhibit airway smooth muscle remodelling in vitro and in vivo.. ICG-001, a small-molecule compound that inhibits the β-catenin/CREB-binding protein (CBP) interaction, strongly and dose-dependently inhibited serum-induced smooth muscle growth and TGFβ1-induced production of extracellular matrix components in vitro. Inhibition of β-catenin/p300 interactions using IQ-1 or inhibition of tankyrase 1/2 using XAV-939 had considerably less effect. In a mouse model of allergic asthma, β-catenin expression in the smooth muscle layer was found to be unaltered in control versus ovalbumin-treated animals, a pattern that was found to be similar in smooth muscle within biopsies taken from asthmatic and non-asthmatic donors. However, β-catenin target gene expression was highly increased in response to ovalbumin; this effect was prevented by topical treatment with ICG-001. Interestingly, ICG-001 dose-dependently reduced airway smooth thickness after repeated ovalbumin challenge, but had no effect on the deposition of collagen around the airways, mucus secretion or eosinophil infiltration.. Together, our findings highlight the importance of β-catenin/CBP signalling in the airways and suggest ICG-001 may be a new therapeutic approach to treat airway smooth muscle remodelling in asthma.

Topics: Airway Remodeling; Animals; Anti-Asthmatic Agents; Asthma; beta Catenin; Bridged Bicyclo Compounds, Heterocyclic; CREB-Binding Protein; Disease Models, Animal; Dose-Response Relationship, Drug; Extracellular Matrix; Female; Gene Expression Regulation; Heterocyclic Compounds, 3-Ring; Humans; Mice; Mice, Inbred BALB C; Muscle, Smooth; Ovalbumin; Pyrimidinones

The epithelium of asthmatics is characterized by reduced expression of E-cadherin and increased expression of the basal cell markers ck-5 and p63 that is indicative of a relatively undifferentiated repairing epithelium. This phenotype correlates with increased proliferation, compromised wound healing and an enhanced capacity to undergo epithelial-mesenchymal transition (EMT). The transcription factor β-catenin plays a vital role in epithelial cell differentiation and regeneration, depending on the co-factor recruited. Transcriptional programs driven by the β-catenin/CBP axis are critical for maintaining an undifferentiated and proliferative state, whereas the β-catenin/p300 axis is associated with cell differentiation. We hypothesized that disrupting the β-catenin/CBP signaling axis would promote epithelial differentiation and inhibit EMT. We treated monolayer cultures of human airway epithelial cells with TGFβ1 in the presence or absence of the selective small molecule ICG-001 to inhibit β-catenin/CBP signaling. We used western blots to assess expression of an EMT signature, CBP, p300, β-catenin, fibronectin and ITGβ1 and scratch wound assays to assess epithelial cell migration. Snai-1 and -2 expressions were determined using q-PCR. Exposure to TGFβ1 induced EMT, characterized by reduced E-cadherin expression with increased expression of α-smooth muscle actin and EDA-fibronectin. Either co-treatment or therapeutic administration of ICG-001 completely inhibited TGFβ1-induced EMT. ICG-001 also reduced the expression of ck-5 and -19 independent of TGFβ1. Exposure to ICG-001 significantly inhibited epithelial cell proliferation and migration, coincident with a down regulation of ITGβ1 and fibronectin expression. These data support our hypothesis that modulating the β-catenin/CBP signaling axis plays a key role in epithelial plasticity and function.

Topics: Actins; Asthma; beta Catenin; Bridged Bicyclo Compounds, Heterocyclic; Cell Differentiation; Cell Movement; Cell Proliferation; E1A-Associated p300 Protein; Epithelial Cells; Epithelial-Mesenchymal Transition; Fibronectins; Gene Expression Regulation; Humans; Keratin-19; Keratin-5; Peptide Fragments; Primary Cell Culture; Pyrimidinones; Respiratory Mucosa; Sialoglycoproteins; Signal Transduction; Snail Family Transcription Factors; Transcription Factors; Transforming Growth Factor beta1