Vitro-retinal proliferation

M. (1991) EGF and TGF-a stimulate retinal neuroepithelial cell proliferation in vitro. Neuron 6 923-936. 

Scherer, J. and Schnitzer, J. (1994) Growth factor effects on the proliferation of different retinal glial cells in vitro. Dev. Brain Res. 80 209-221. 

PPARy is expressed in bovine retinal endothelial cells [49]. In vitro studies found thiazoUdinediones inhibited the effects of vascular endothelial growth factor on migration and proliferation of retinal endothelial cells. In vivo, intravitreous injection of both agents inhibited development of retinal neovascularization. These results indicate that thiazolidinediones may be effective in the treatment of diabetic retinopathy pending further research in humans [49]. 

Vitamin A (retinol) is a fat-soluble vitamin important for the maintenance of skin, bone, and blood vessels, as well as for the promotion of vision (Theodosiou et al. 2010). It is obtained from the diet either as all-trans-retinol, retinyl esters, or P-carotene (Blomhoff and Blomhoff 2006) and is stored in the liver (Moise et al. 2007). Vitamin A is converted to retinoic acid (RA), which is formed mainly through intracellular oxidative metabolism by retinal dehydrogenases (RALDHs) (Lampen et al. 2000). RA plays important roles in embryonic development, organogenesis, tissue homeostasis, cell proliferation, differentiation, and apoptosis (Theodosiou et al. 2010). In adult mammals, RALDH is found in intestinal epithelial cells (lECs) and gut associated-dendritic cells (DCs) from Peyer s patches and mesenteric lymph nodes (Iwata 2004, Coombes et al. 2007). Gut-associated DCs and lECs can metabolize vitamin A to RA in vitro (Lampen 2000), which indicates they may be a source of RA in gut mucosa. RA binds to two families of nuclear receptors, RA receptor (RAR) isotypes (a, p, and y) and retinoic X receptor (RXR) isotypes (a, p, and y). RAR and RXR form heterodimers and interact with retinoic acid response elements (RAREs) within the promoters of retinoic acid responsive genes (Blomhoff and Blomhoff 2006). RAR is ubiquitously expressed and up-regulated by RA. RXR also... 

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