The developing chick retina is an extrapituitary site of growth hormone (GH) synthesis and action. GH, GH receptor (GHR) and their mRNAs are present in the neural retina when the neural cells are undergoing proliferation and differentiation during early embryogenesis. It is thus likely that GH acts as an autocrine or paracrine in this location. The present study shows that intra-vitreal injection of a chick GH (cGH) small interfering RNA (siRNA) into the eyes of early embryos [embryonic day (ED) 4] suppresses GH expression in the neural retina and increases the incidence of spontaneous retinal cell death. Our current work also demonstrates a reduction of local IGF-1 expression after retinal GH gene knockdown, suggesting that GH action in retinal cells is regulated through IGF-1 signalling. These results demonstrate that retinal GH is an autocrine/paracrine hormone that acts as a neuroprotective factor in the retina of chick embryos.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:AEU.10048/1924 |
| Date | 06 1900 |
| Creators | Lin, Wan-Ying |
| Contributors | Steve Harvey (Physiology), Esmond J. Sanders (Physiology), Yves Sauve (Ophthalmology), Hamid R Habibi Bio Sci/U of C), Ed Karpinski (Physiology) |
| 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 | Thesis |
| Format | 3301989 bytes, application/pdf |
| Relation | Sanders E. J., W-Y. Lin, E. Parker E, and S. Harvey (2010) Growth hormone expression and neuroprotective activity in a quail neural retina cell line. General and Comparative Endocrinology, 165, 111-119, Sanders E. J., W-Y. Lin, E. Parker, and S. Harvey (2011) Growth hormone promotes the survival of retinal cells in vivo. General and Comparative Endocrinology, in press. |
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