IPF is a progressive disease, characterized by dysregulated fibrosis of the extracellular matrix (ECM). The pathobiology of the disease is still unknown, and the median survival post-diagnosis is about 3-5 years. The two current US FDA approved drugs for IPF (nintedanib and pirfenidone) slow, but fail to reverse, disease progression.
There is cumulating research that suggests the ECM is an active player in fibrosis. In this thesis, we summarized the current knowledge of ECM-cell interactions in the context of pulmonary fibrosis. To gain more mechanistic insight into the ECM characteristics that dictate cell behavior, we established a 3D ECM ex vivo system to assess the nonfibrotic and fibrotic ECM’s effect on fibroblasts. The ECM appears to promote both pathological and physiological cellular changes, depending on its structural and compositional properties. We also used this 3D ex vivo system as a preclinical tool to test the effect of directly inhibiting mechanotransduction in the fibrotic ECM – fibroblast profibrotic relationship. Lastly, since the fibrotic ECM seems to play a key role in progressive fibrosis, we evaluate if researchers are appropriately using the bleomycin model by starting interventions after ECM fibrosis is established. Over the past decade in the field, there has been an overall improvement in the appropriate therapeutic timing. In the preventative studies, however, there is still an inadequate characterization of inflammation. There is also poor transparency of preclinical-bleomycin data for clinically tested interventions for IPF. Addressing these shortcomings may improve the utility of the model at predicting an intervention’s success in clinical trials.
These findings illustrate the ECM’s role in driving pulmonary fibrosis. Therefore, the ECM should be further investigated to understand disease progression, and reproduced in preclinical models to test interventions. This will improve the transition of pathobiological findings into efficient drug development for this devastating disease. / Thesis / Candidate in Philosophy / Idiopathic pulmonary fibrosis (IPF) (idiopathic - unknown cause; pulmonary - lungs; fibrosis - scarring) is characterized by progressive scarring of the lung extracellular matrix (ECM). The ECM is an organ’s backbone that provides structural and biochemical support to surrounding cells. Continued ECM scarring can lead to difficulty breathing, cough, and ultimately death. The cause of IPF is unknown, however, studies suggest that the scarred ECM can promote further scarring, and cause disease progression. In this thesis, we summarized the current knowledge of how the ECM interacts with cells. Using a 3D model we see that depending on the ECM’s structure and composition, it can promote both disease and healthy cellular changes. Lastly, we evaluate if researchers are appropriately using the bleomycin model (most common preclinical model for pulmonary fibrosis) by testing interventions after ECM fibrosis is established. We propose changes to improve its usefulness as a preclinical tool for IPF.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/24749 |
| Date | January 2019 |
| Creators | Upagupta, Chandak |
| Contributors | Kolb, Martin, Medical Sciences |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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