Abstract
Purpose: :
Müller cell differentiation and migration has been strongly implicated in degenerative retinal disorders and retinal injury. Work already performed suggests that Müller cell derived stem cells have the potential to differentiate into other retinal cell types, including photoreceptors. Other work has shown that the biochemical and physical properties of culture platforms can influence Müller cell behavior. We performed a series of experiments using human Müller cell derived neurospheres, or stem cells, to determine whether the substrate onto which these cells are placed can influence their capacity to remain in an undifferentiated state or drive their re-differentiation.
Methods: :
MIO-M1 cells were grown to confluency in DMEM/F12 media, then cultured in complete Neurobasal media to stimulate neurosphere formation. Once formed, neurospheres were transferred onto 6-well plates with DMEM/F12 and 10%FBS. Control cells were grown on plastic. Experimental cells were grown on wells coated with each of the following: Biocoat-Gelatin, Collagen I, fibronectin and Poly D-Lysine. After 7 days, cells were harvested for mRNA extraction. PCR was used to look at expression of GFAP, Sox 2, Pax 6, Vimentin and Nestin. Bright-field photography was used to document morphological changes.
Results: :
Neurospheres plated on Poly D-Lysine showed sustained retention of their morphology, with attachment and spindle cell growth by day 5. Extensive cell death was noticed in collagen and fibronectin coated plates, with robust attachment and spindle cell morphological changes and growth on gelatin coated plates. GFAP expression remained consistently low in spheres harvested from Poly D-Lysine plates, while Sox 2 and Pax 6 remained consistently expressed in cells from gelatin coated plates despite the significant change in their morphology.
Conclusions: :
Different surfaces have the capacity to significantly alter Müller derived stem cells. This is important when considering Müller derived stem cells a potential source and tool for retinal regeneration.
Keywords: Muller cells • retina • regeneration