Research Stijn Verleden

Abstract

A recent Lancet commission highlighted the significant and increasing burden of chronic obstructive pulmonary disease (COPD) and the need for fundamental changes in the way we think about this disease. Currently, the diagnosis of COPD requires spirometric airway limitation (FEV1/FVC <70%). However, significant lung damage may already have occurred before abnormalities in lung function are identified. Recently, the term pre-COPD has therefore been proposed to refer to individuals without airflow obstruction, but who are at increased risk of subsequently developing COPD based on their symptoms, lung function, or structural abnormalities. Importantly, the pathophysiological mechanisms underlying pre-COPD are largely unknown. Recently, our research group demonstrated a >40% reduction of small airways in pre-COPD patients compared to healthy (smoking) controls, which was similar to established GOLD I COPD. In this project, the cellular and molecular mechanisms underlying structural abnormalities in pre-COPD will be extensively investigated, with a focus on inflammation and epithelial remodeling. A comprehensive strategy will be employed, entailing a thorough transcriptomics investigation and validation at the tissue level, complemented by functional experiments utilizing patient-derived bronchial epithelial cell cultures. Understanding early pathological changes in pre-COPD will ultimately enable earlier and improved diagnosis and therapeutic intervention in (pre-)COPD patients.

Researcher(s)

• Promoter: Lapperre Therese
• Co-promoter: Smet Annemieke
• Co-promoter: Verleden Stijn
• Fellow: Voet Hanne

Research team(s)

• Laboratory Experimental Medicine and Pediatrics (LEMP)

Project type(s)

• Research Project

Abstract

Within this project, we want to further perform synchrotron scanning to further investigate the morphological and molecular changes in chronic obstructive pulmonary disease (COPD). COPD is the third leading cause of death worldwide causing 3.23 million deaths in 2019 according to WHO. In Belgium, it is estimated that approximately 800.000 residents suffer from COPD, with about half of these people not knowing they have COPD, leading to a projected financial loss of about 1000 euro per Belgian resident due to this devastating disease. The major risk factor for COPD is persistent exposure to cigarette smoke and pollutants. Its pathophysiology is characterized by loss and remodeling of the (small) airways and destruction of the alveoli leading to airspace enlargement. However, there is a large gap between what is known from CT analysis relative to what we know from microscopic analysis of pathological specimens. Using synchrotron analysis of entire human lung explants with varying COPD severity, they want to perform an in depth analysis of the vascular, parenchymal and airway changes in the lung. These lungs will be collected in close collaboration with the thoracic surgery, pneumology and pathology department from patients undergoing lobectomy, transplantation or autopsy within the University Hospital of Antwerp. The the entire bronchial and vascular tree will be segmented and will be used to quantify the number of airways/vessels per generation, the number of remodeled airways, segment lengths, branching angles, airway/vascular diameters etc. Based on these scans, further areas will be selected for deeper investigatation on the molecular level. This regions will subsequently be carefully excised and matched to the synchrotron images and be further subjected to multiplex immunofluorescence and spatial transcriptomics. This will allow a both targeted and unbiased analysis of the molecular changes in the lung both on the RNA and protein level. This targeted analysis will be focused on the airway epithelial cell composition, identifying different endothelial subsets and inflammatory cells in relation to the morphological changes. The combination of the unique access to the synchrotron facilities which is the only one worldwide that can scan entire organs with microscopic resolution and state-of-the-art molecular tools will be transformative in advancing our knowledge on this devastating disease.

Researcher(s)

• Promoter: Verleden Stijn

Research team(s)

• Antwerp Surgical Training, Anatomy and Research Centre (ASTARC)

Project type(s)

• Research Project

Abstract

Hierarchical Phase-Contract Tomography (HiP-CT) has been developed as an innovative way to study an intact human organ in 3D resolution on a near-microscopic scale. Within this project we want to leverage HiP-CT to investigate human lungs from patients with COPD and lung fibrosis. We aim to identify and quantify disease specific features and unravel the role of the vasculature in the pathophysiology of chronic lung diseases. HiP-CT will provide us with the advantage of comparing disease specific features across the entire organ (and thereby allow us to compare none vs mild vs severely affected tissue with the same lung) and quantify this in 3 dimensions which is not possible with any of the existing technologies. Using this highly detailed information we will segment and quantify the entire bronchial and vascular system and compare this in health and disease. We next want to leverage this knowledge to also obtain deeper biologic information by performing spatial analysis in the same organs using multiplex immunofluorescence and spatial transcriptomics. Lastly, we want to validate our findings in a larger collection of organs, as well as organs or biopsies with early disease from our own biorepository to validate the importance of our findings. We are convinced that by combining state-of-the-art imaging technology with next generation biological tools, we will get one step closer in our understanding of chronic lung diseases which is desperately needed given their poor outcome.

Researcher(s)

• Promoter: Verleden Stijn
• Fellow: Van der Rauwelaert Jonas

Research team(s)

• Antwerp Surgical Training, Anatomy and Research Centre (ASTARC)

Project type(s)

• Research Project

Abstract

Visualisation of intact organs with microscopic resolution can learn us a lot about the morphological and molecular changes in health and disease. Specifically for the lung, we do not have sufficient insights about the changes that are associated with chronic lung disease. Therefore within this project, we want to leverage unique methodology (hierarchic phase contrast tomography) to image the complete lung at a microscopic resolution. We aim to better understand the changes associated with disease. Unique with this technology is that the vasculature can also be directly visualised. Therefore we want to utilize this tool to better understand what happens with the airways, the vasculature, the alveoli, the pleura and most interestingly how these interact. We also aim to associate our findings with the in vivo pre-operative omaging, but also to the pathological diagnosis. These insights will be crucial to better understand the mechanisms of chronic lung diseases.

Researcher(s)

• Promoter: Verleden Stijn

Research team(s)

• Antwerp Surgical Training, Anatomy and Research Centre (ASTARC)

Project type(s)

• Research Project

Abstract

Pulmonary diseases are a major cause of morbidity and mortality. A diversity of different lung diseases exists each associated with their own presentation, prognosis, and pathophysiologic mechanisms. Leveraging a macro to micro approach using state-of-the-art technologies such as HiP-CT, microCT and spatial transcriptome analysis on wellcharacterized human lungs and innovative animal models such as primary bronchial epithelial culture and a murine lung transplant model, the aim of this application is to better diagnose and better understand the pathophysiological mechanisms of lung diseases. Several topics are detailed where the overall aim is to improve the diagnosis of lung disease. Firstly, we seek to consolidate the tumor classification of surgically resected lung lobes more adequately by investigating micro-lesions in the lung. Secondly, we want to assess suitability of donor lungs for lung transplantation via ex vivo imaging. Thirdly, we aim to find better markers of small airway disease in patients with smoking induced lung changes. Fourthly, we seek to directly correlate in vivo CT data to ex vivo histological and functional data to construct a virtual biopsy. Next to better diagnosis, it is also important to improve the knowledge on the pathophysiological mechanisms of lung diseases. Therefore, the morphological changes and pathophysiological mechanisms of several lung diseases will be further explored in comparison to physiological lung aging. HiP-CT analysis will be used on aging and end-stage lung specimens to provide an unprecedented view on the bronchial and vasculature changes at extreme high resolution on an entire specimen. As this approach is logistically difficult in early disease specimens, microCT will be used to compare bronchial and vasculature changes in early to late-stage disease and aging. To further investigate the mechanisms of this lung remodeling, primary bronchial epithelial cells will be harvested and used to investigate the immunoreactivity to infectious and non-infectious triggers. The lung tissue itself will also be subjected to in-depth investigation by staining for different inflammatory markers, by scanning electron microscopy to investigate collateral ventilation and by spatial transcriptome/single nuclear sequencing analysis. Lastly, the role of microvascular alterations will be further investigated using a murine orthotopic lung transplant model where the sequence of vascular changes will be investigated via bulk transcriptome analysis and in/ex vivo imaging techniques. Lastly, pharmacological inhibition will be attempted to confirm the involvement of the microvasculature. Ultimately, this ambitious and innovative project will lead to tremendous new insights which could help in the diagnosis of (early stage) lung disease and will definitely be important to better understand the pathophysiology of respiratory diseases. This will assist in assessing disease prognosis and eventually therapy, which is desperately needed given the high- morbidity and mortality of lung diseases.

Researcher(s)

• Promoter: Verleden Stijn
• Fellow: Verleden Stijn

Research team(s)

• Antwerp Surgical Training, Anatomy and Research Centre (ASTARC)

Project type(s)

• Research Project