Marrow stromal cells (MSCs) are pluripotent stem cells which may participate in the repair of damaged organs. We tested the hypothesis that MSCs can be recruited to the heart upon myocardial infarction, and play pathophysiological roles in the subsequent healing and adaptation process. An animal model was created with labeled MSCs in its bone marrow and then a myocardial infarction produced. Donor MSCs from isogenic Lewis rats were harvested, multiplied in culture and labelled. Labelled cells were intravenously injected into the recipient rats and one week later upon the engraftment of these labelled MSCs within the bone marrow, rats underwent a coronary artery ligation or sham operation. The hearts were removed at various time points and the presence of labelled cells in the heart was confirmed and their phenotypes identified. We confirmed the presence of labelled cells in the rat bone marrows and the presence of labelled cells in the infarcted myocardium at all time points studied, but not in the normal hearts. There was evidence for myogenic differentiation with some labelled cells expressing smooth muscle/myofibroblast phenotypes and appearing to participate in vasculogenesis. Our evidence is consistent with the hypothesis that myocardial infarction may send a signal to recruit MSCs to the injured heart, where they undergo milieu-dependent differentiation. The ability of these cells to express various phenotypes may allow them to participate in the pathophysiology of post-infarct remodeling and angiogenesis. Therapeutic implantation of MSCs thus may further enhance such effects.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.32763 |
| Date | January 2001 |
| Creators | Bittira, Bindu. |
| Contributors | Chiu, Ray C-J (advisor), Shum-Tim, Dominique (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Division of Cardiothoracic Surgery.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001862288, proquestno: MQ78835, Theses scanned by UMI/ProQuest. |
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