The biggest challenge to islet transplantation is preserving cell mass and function. It is known that the stresses encountered during islet isolation have deleterious effects on beta-cell physiology. The nature of these effects, however, are incompletely known, partly due to the heterogeneity of islet preparations. Using a combination of laser capture microdissection and microarray technology, we therefore sought to determine the beta-cell specific events that occur as a result of islet isolation and in vitro culture. Our data shows that islet isolation and in vitro culture induce a large inflammatory response that is NF-kB dependent and involves the upregulation of several pro-inflammatory cytokines such as IL-8, IL-1 and MCP-1. Furthermore, several transcription factors involved in ß-cell differentiation, such as NeuroD1, NKX2.2, and MafA were decreased, providing insight into mechanisms of beta-cell dedifferentiation. Therefore, therapies aimed at targeting NF-kB and re-expressing transcription factors necessary to beta-cell function should be explored further. / Le stress subi durant l'isolation des îlots de Langerhans a des effets négatifs sur la physiologie des cellules bêta. Nous avons tenté de déterminer les événements survenant suite à une isolation d'îlots et de leur culture in vitro grâce à la capture et découpage laser et la puce à gènes. Nos résultats démontrent que l'isolation d'îlots et leur culture in vitro produisent une importante réponse inflammatoire. Cette réponse dépend de la protéine NF-kB et implique une augmentation de plusieurs cytokines pro-inflammatoires, incluant IL-8, IL-1, et MCP-1. Aussi, plusieurs facteurs de transcription essentiels dans la différenciation des cellules bêta comme NeuroD1, NKX2.2, et MafA ont diminué, suggérant que les cellules bêta se dédifférencient après leur isolation et culture in vitro. Par conséquent, les thérapies visant NF-kB et la réexpression des facteurs de transcription nécessaires à la fonction des cellules bêta devraient être explorées plus en détails.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.97157 |
| Date | January 2011 |
| Creators | Jetha, Arif |
| Contributors | Steven Paraskevas (Internal/Supervisor) |
| 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 | French |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Surgery) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | Electronically-submitted theses. |
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