Proteomic Analysis of the Resident Cell Types in the Heart: a Focus on the Fibroblast and Its Secreted Proteome
Year: 2017
Type: dissertation
Abstract: The cardiac fibroblast (CF) is a key cellular component of the heart, being reported in some cases as the largest cell population in the heart. CF play a major role in the homeostasis of the tissue, being involved in extracellular matrix (ECM) maintenance and turnover. It is also important in the heart's pathophysiology and stress response as CF are secretory cells that affect other cell types in the heart. This thesis includes studies that investigate how the CF proteome is altered during hypoxic stress. In brief, proteomic analysis of the CF identified 6163 proteins with subsets altered due to hypoxia. Of particular interest was the CF secreted proteome, which when introduced caused an altered response to hypoxia/reoxygenation in cardiomyocytes. Additionally, it was investigated how the CF differed at the proteome level to the other resident cell types in the heart: the cardiomyocyte (CM), endothelial cell (EC), and smooth muscle cell (SMC). This was in an effort to identify alternative cell type-enriched markers to identify the specific cell type contributors of proteome changes in the heart, which is generally performed at the tissue-level, where cellular resolution of these changes is lost. The second set of proteome studies identified 367 FB-enriched, 97 CM-enriched, 340 EC-enriched, and 52 SMC-enriched proteins. We rank ordered cell-specific enrichment of proteins via magnitude and significance of enrichment. With enrichment data being the most pronounced in FB, we then validated expression of multiple highly-ranked candidates (GRB2, AKR1B1, and PRDX1) in myocardial infarction tissue sections. Immunofluorescent staining showed higher expression in the highly fibrotic infarct scar of 4-week post-MI relative to border and non-infarct regions, confirming the cellular enrichment of our candidates. Potential markers of each cell type have been validated by HPA and immunofluorescent imaging of MI.
Source: TSpace (University of Toronto)
Author: Jake Cosme
Language: English
Subfield: Cardiology and Cardiovascular Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W3091323020