Research Project: Development of 3D in vitro lung airway models to investigate the role of hypoxia in airway remodeling in asthma 

Asthma is a chronic inflammatory lung disease, and subepithelial fibrosis (SF) is one of its hallmarks. This fibrosis is caused by excessive accumulation of extracellular matrix (ECM) proteins – especially collagen type I. This makes the airways become thickened and obstructed, leading to tissue stiffening and a reduction in lung function. Obstructed airway reduces oxygen supply to the tissues. Evidence shows that low oxygen concentration in the lungs (known as “hypoxia”) regulates the production of ECM proteins (such as collagen type I), enzymes, etc. 

The interactions between the ECM and tissue-resident cells, the mechanisms driving ECM alternations in asthma, and the role of oxygen in this process are poorly understood. This research will be the first to integrate two novel technologies, multimodal Raman microspectroscopy and Second Harmonic Generation (RM-SHG), and high-resolution Nonlinear Optical Microscopy (NLOM) to understand fundamental mechanisms associated with low oxygen levels (hypoxia) and ECM alternation in asthma. 

Research Project: Sex as a biological variable in immunomodulation of airway inflammation by Innate Defence Regulator (IDR) peptides

Asthma is the most common chronic respiratory disease affecting nearly 3 million Canadians including children. Around 15% patients do not respond to available steroid therapies and represent the major burden of asthma accounting for annual healthcare costs of $2B. Also, common steroid therapies can increase the risk of lung infections, which can make asthma worse. New therapies are urgently needed that can alleviate steroid-unresponsive disease without compromising the ability to resolve infections.

There is a clear sex bias in asthma, for example adult females experience greater disease severity and are more likely to develop steroid-resistance, compared to males. These sex-related differences are largely ignored during drug development. Effective development of new treatments must consider the differences in disease and response to therapy between females and males.

This study focuses on new molecules known as innate defence regulator (IDR) peptides, which can control both inflammation and infection. We have shown that IDR peptides improve breathing capacity in an animal model of asthma, and control cellular processes linked to steroid unresponsiveness. This project aims to develop IDR peptides as a new therapy for asthma, by examining the effects in both females and males concurrently. This research will directly support the development of a new IDR peptide-based therapy for asthma, by taking into consideration how the treatment affects females compared to males. It is entirely possible that we will need to develop sex-specific treatment protocols to provide the most efficient care for asthma sufferers.

Insight into the fibrotic responses in asthma with an unprecedented level of spatial and biochemical specificity will drive the identification of biomarkers active in disruptive airway remodelling and support therapeutic development minimizing the formation of scar tissue observed through the excessive burden of SF.

Research Project: Investigating the role of airway epithelial cell (AEC)-derived semaphorin3E in chronic type-2 high and steroid-resistant type-2 low models of asthma

Asthma is a major health concern in Canada, while inhaled corticosteroids (ICS) are the first-line treatment for persistent asthma, some patients have a poor response to these drugs. This condition is known as steroid-resistant asthma (SRA), with type 2-low (neutrophilic) asthma being a major phenotype of SRA. Understanding the mechanisms behind this resistance is crucial for developing better treatments.

Our research focuses on Semaphorin3E, a protein that our lab has found to reduce asthma severity in preclinical models. Sema3E decreases airway sensitivity, inflammation, and lung tissue scarring. Healthy human lungs naturally produce Sema3E, primarily from airway epithelial cells (AECs). However, in severe asthma cases, Sema3E levels are lower, correlating with decreased lung function, indicating its role in maintaining lung health.

Using two chronic (type-2 high) eosinophilic and (type-2 low) neutrophilic asthma models, we aim to study the effects of AEC-derived Sema3E on asthma. We will also compare the impact of Sema3E with dexamethasone, and explore the combination of both treatments.

Research Project: Evaluating small-airways remodeling and response to therapy in patients with severe asthma using 129Xe MRI ventilation texture features.

Asthma is a chronic lung disease characterized by airway remodelling, chronic inflammation, airway wall thickening, and lumen narrowing. Several clinical tools exist to help diagnose and monitor airway dysfunction. However, these approaches provide measurements that are relatively insensitive to small-airways dysfunction and its associated patchy ventilation which is believed to drive asthma symptoms and worsening.

To address this gap, our project proposes the use of pulmonary functional MRI with inhaled hyperpolarized 129Xe gas. This method has shown promise in previous studies for detecting airway dysfunction with high sensitivity. By tracking small-airways abnormalities, we have an opportunity to enhance our understanding of how the airways respond to asthma therapy. This information will help focus new treatments targeting small-airway abnormalities which we think will lead to better asthma patient outcomes overall. 129Xe MR images will be analyzed using texture analysis—an image analysis technique to determine if the patterns in the MRI reveal abnormalities in lung ventilation due to asthma. By employing machine learning models to these texture features, we aim to identify which are most indicative of changes in the airways, potentially outperforming traditional clinical measurements. This information will be vital in guiding improved treatments for asthma, leading to better patient outcomes.

Research Project: Exploring the molecular interactions between early-onset asthma and cow’s milk allergy

Childhood asthma and food allergies frequently occur together, affecting millions of children globally. Studies show that 4-8% of asthmatic children also have food allergies, and about 50% of children experiencing allergic reactions with respiratory symptoms have food allergies. Despite this common overlap, the reasons behind this connection or how these conditions influence each other at a molecular level remain poorly understood. This study aims to uncover the molecular link between cow’s milk allergy (CMA) and worsening asthma symptoms.

We hypothesize that specific components of cow’s milk proteins, when broken down during digestion, release fragments that trigger allergic pathways, potentially exacerbating asthma. By focusing on cow’s milk as a model system, the aim is to gain insights that can be applied to other food allergies as well. Utilizing advanced computational tools and bioinformatics techniques, this research seeks to identify and analyze these specific protein fragments, simulate digestion processes, and examine how they interact with the immune system. Additionally, a machine learning model will be developed based on data from children with CMA. This model will then be used to help us predict if other milk alternatives or food proteins might also worsen asthma symptoms.

The goal is to improve quality of life for affected children by better understanding how CMA may worsen asthma. Our findings could lead to improved risk prediction, more targeted treatments, and personalized dietary advice for children with both conditions.

Research Project: An evaluation of gas-exchange abnormalities in moderate-severe asthma over time.

Asthma is a disease that inflames and narrows the airways, so treatments usually focus on relieving airway symptoms. However, new research suggests that other parts of the lungs, like blood vessels and the alveoli where gas exchange takes place, might also be involved in asthma. Studies indicate that lung blood vessels may change in severe asthma, similar to serious heart disease. We aim to understand the role of these pulmonary blood vessels and areas of gas exchange in asthma patients.

Using hyperpolarized 129Xe magnetic resonance imaging (MRI) and spectroscopy, we can visualize and measure gas exchange and ventilation in the lungs. We plan to evaluate 129Xe MR gas-exchange measurements in a large group of asthma patients with varying severity and age-matched healthy individuals. We will also follow a subset of moderate-to-severe asthma patients over time to see how their gas-exchange measurements change with treatment.

While gas-exchange abnormalities and blood flow changes are known in many diseases including COVID-19, few studies have examined gas-exchange in asthma with large participant groups. This project will be the first large-scale investigation to explore whether gas-exchange and blood vessel abnormalities are linked in asthma. By comparing healthy individuals with asthma patients and observing changes over time with treatment, we aim to confirm these gas-exchange abnormalities, potentially establishing them as a new treatable trait in asthma beyond the airways.

Research Project:  Data from the CHILD cohort study: functionally linking the early-life gut microbiome to health and disease

Allergic diseases affect hundreds of millions of children worldwide and continue to increase in prevalence. Many risk factors for allergic diseases, such as antibiotic usage, also influence microbes and their genes within the gut, which, together, are commonly known as the gut microbiome. Maturation of the gut microbiome usually occurs at the same time as the development of healthy immune tolerance. However, if microbiome maturation is abnormal, allergic sensitization can emerge in some children as a result.

My research combines school-age allergic diagnoses with early-life gut microbiome composition, functional capability, and metabolite concentrations for the quantification of a ‘normally’ maturing gut microbiome. This data primarily stems from CHILD (n=3,455), a large Canadian longitudinal study with robust information on participant environment and microbiome. To increase the strength and relevance of my findings, I will not only identify associations in CHILD, but I am also working with my colleagues and collaborators to validate our findings in other populations with clinical and microbiome data, such as the Copenhagen Prospective Study on Asthma in Childhood (COPSAC). 

The aims of my research are to (1) identify unifying gut microbiome maturation signatures in asthma, allergic rhinitis, food allergy, and atopic dermatitis, collectively called the ‘Allergic March’, (2) functionally link antibiotic usage to the onset of specific allergic diseases using microbiome data, and (3) connect microbial-dependent influences on participant immune cell profiles to allergy. My investigation of the early-life gut microbiome will thus empower new predictive and preventive strategies to avoid allergic diseases.

Research Project: Mapping airway remodelling in asthma using multimodal Raman-Second Harmonic Generation imaging and machine learning

Asthma is a chronic inflammatory disease, impacting approximately 11% of the Canadian population. Inhaled allergens damage the tissue barrier lining the lungs, leading to the inflammation of airways and difficulties in breathing. To remodel impaired tissue, damaged airways trigger a complex cellular response, denoted by the excessive accumulation of extracellular matrix (ECM) proteins; particularly collagen I. Evidence suggests that this fibrotic response, known as subepithelial fibrosis (SF), contributes to tissue stiffening, airway blockage and an overall reduction in lung function.

With the goal of setting a new precedence for imaging and to better visualize ECM protein deposition at high resolution, our research applies a label-free multimodal imaging system embedded with the technologies of both Raman microspectroscopy and Second Harmonic Generation. This imaging system is the only of its kind in Canada, and is used to develop biochemical maps of tissues and cells while simultaneously detecting signals related to fibrillar collagen. Due to the complex nature of the data obtained, the development of novel approaches based on machine learning (ML) strategies to identify biomarkers associated with asthmatic airway remodelling is necessitated. Using ML, an automated classification pipeline will be developed to characterize spectral signatures unique to the basement membrane, epithelium and lamina propria of airways.

Insight into the fibrotic responses in asthma with an unprecedented level of spatial and biochemical specificity will drive the identification of biomarkers active in disruptive airway remodelling and support therapeutic development minimizing the formation of scar tissue observed through the excessive burden of SF.

Research Project: Sex as a biological variable in immunomodulation of airway inflammation by Innate Defence Regulator (IDR) peptides

Asthma is the most common chronic respiratory disease affecting nearly 3 million Canadians including children. Around 15% patients do not respond to available steroid therapies and represent the major burden of asthma accounting for annual healthcare costs of $2B. Also, common steroid therapies can increase the risk of lung infections, which can make asthma worse. New therapies are urgently needed that can alleviate steroid-unresponsive disease without compromising the ability to resolve infections.

There is a clear sex bias in asthma, for example adult females experience greater disease severity and are more likely to develop steroid-resistance, compared to males. These sex-related differences are largely ignored during drug development. Effective development of new treatments must consider the differences in disease and response to therapy between females and males.

This study focuses on new molecules known as innate defence regulator (IDR) peptides, which can control both inflammation and infection. We have shown that IDR peptides improve breathing capacity in an animal model of asthma, and control cellular processes linked to steroid unresponsiveness. This project aims to develop IDR peptides as a new therapy for asthma, by examining the effects in both females and males concurrently. This research will directly support the development of a new IDR peptide-based therapy for asthma, by taking into consideration how the treatment affects females compared to males. It is entirely possible that we will need to develop sex-specific treatment protocols to provide the most efficient care for asthma sufferers.

Research Project:  Basophilic oncostatin M fuels nociceptor neuron-induced asthma

Despite affecting less than 10% of asthmatic patients, severe asthma accounts for 60% of the asthma healthcare cost due to the lack response to corticosteroid treatments. Recent advance of single-cell gene profiling reveals a population of airway sensory neurons expressing similar genes as neurons sensing skin itch. However, molecular and pharmacological characterizations of this population are insufficient. With real-time calcium imaging, we can visualize the calcium influx, a neuronal activation event, in response to different stimulants. We can thus cluster the neurons based on their reactivity to different drugs as well as evaluate neuron’s sensitivity under normal and asthmatic condition.

We have thus far demonstrated that lysophosphatidic acid-responding neurons and serotonin-responding neurons are two distinct populations, which respectively represent jugular and nodose nociceptors in vagal sensory ganglia, from where the airway sensory neurons arise.

We also noticed that some jugular neurons express the receptor of oncostatin M (OSM), a cytokine associated with exaggerated itch sensation in atopic diseases. We then ask if OSM is expressed in asthmatic context and by which cells. With cell sorting and RT-qPCR techniques, we identified lung basophils as the main cellular source of OSM under normal and asthmatic conditions. As it sensitizes itch neurons, OSM can also sensitize vagal sensory neurons, shown by our calcium imaging data.

Whether OSM affects asthmatic pathophysiology through sensitizing airway sensory neurons is yet to be determined. We hope this novel neuroimmunology pathway provides a new possibility in seeking alternatives to glucocorticoid treatment.

Research Project:  DNA methylation changes induced by prenatal cannabis exposure associated with asthma in mice

Since legalization, there has been an increase in the use of cannabis in Canada, but worryingly there are few clear rules for its use and safety during pregnancy. Exposure to inhaled particulates in early life from other sources, including wildfires, tobacco smoke, or pollution, have known health outcomes leading to risk of asthma. Early life cannabis exposure has been studied extensively in the brain, but no clear evidence is available for respiratory conditions like asthma. We plan to examine the molecular effects of prenatal and early life cannabis smoke on asthma development by examining epigenetics, or change in DNA function without change in DNA sequence. Specifically, this project will use DNA methylation (DNAm) as it is the best characterized.

We know prenatal exposure to some environmental pollutants including tobacco smoke
causes changes in DNAm, but we do not yet know exactly how these changes cause lung problems like asthma. We will use a mouse model which will mimic our established tobacco exposure paradigm and expose pregnant mice to cannabis smoke. We will then examine their offspring’s lung tissue to find DNAm changes at specific genes. By comparing these changes with to our recent findings on DNAm changes due to tobacco exposure, we can identify common patterns that could indicate potential novel genes and their mechanisms in causing asthma.

We hope that by identifying the particular mechanisms involved, in the future we can prevent or reverse the negative impacts of cannabis and tobacco smoke on the lungs that increase the risk of asthma.

Research Project:  Quantitative Imaging to Understand the Early Manifestation and Therapeutic Relevance of Abnormal Airway Morphology and Function in Asthma

Approximately 3.8 million Canadians are living with asthma, a chronic disease that impacts the airways and makes breathing difficult. For most people with asthma, symptoms can be adequately controlled, and normal lung function can be maintained with medications that are delivered by inhalation. Unfortunately, however, some people with asthma are considered to have uncontrolled or more severe disease as commonly prescribed inhaled medications do not improve their symptoms, lung function, or risk of an asthma attack. There might be several reasons for this. One might be that anatomical abnormalities in the structure of the airways originate early in life, which are not hallmark and treatable components of asthma. Alternatively, inhaled medicines may not be reaching the right areas in the lungs due to abnormalities in the structure of the airways. Scientists have started to apply high-resolution medical imaging methods to study this. Using advanced magnetic resonance imaging and computed tomography techniques, we will investigate if abnormal features of airway structure: (1) are present, and explain reduced lung function, in early adulthood, (2) have unique temporal trajectories indicative of progressive or non-progressive disease in early adulthood, and (3) influence the effectiveness of first-line inhaled medications. Knowledge gained from this research will improve our understanding of airway disease in asthma and will be applied to improve how asthma is managed and how asthma medications are developed and delivered.

Research Project:  Investigating the interactions of air pollution and an anti-inflammatory asthma medication using scRNA sequencing

With the high prevalence of global air pollution, asthmatic individuals are at increased risk of developing respiratory complications. Asthma exacerbations can cause inflammation of the airways leading to breathing difficulties, necessitating the need for prescription medications. Inhaled corticosteroids (ICS) are a common asthma medication that reduces inflammation, but previous studies show that these medications are less effective following exposure to air pollutants. Despite prior research, the exact mechanisms of how ICS treatment is disrupted remain elusive. A lack of understanding between ICS and air pollution can cause medical practitioners to incorrectly access their patient’s condition, leading to under or overprescription of ICS and resultant adverse effects. Regardless of dosage, greater knowledge of ICS administration can aid in reducing treatment expenses by optimizing quality of care. For these reasons, the aim of this project is to understand how air pollution affects responses to ICS under well controlled conditions in human participants. More specifically, we can discern which cell-types and genes are directly involved in this process, with the hopes of identifying targets that may explain any decreased efficacy of ICS treatment following air pollution exposure.

Identification of gene targets can be determined using single-cell RNA sequencing technology, where we can find unique responses in individual cell-types and genes in ICS-treated participants exposed to air pollution or filtered air. Our research aims to guide improvements in ICS administration policies, ICS development or add-on medications to reduce the burden on healthcare services caused by air pollution.