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Inhibition of Notch pathway enhances photoreceptor commitment from cultured retinal stem cells
Author(s) -
MONTAVON P,
ARSENIJEVIC Y
Publication year - 2009
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2009.218.x
Subject(s) - peripherin , notch signaling pathway , microbiology and biotechnology , retinal , retina , population , cellular differentiation , biology , photoreceptor cell , cell , muller glia , stem cell , chemistry , progenitor cell , signal transduction , neuroscience , genetics , biochemistry , medicine , environmental health , gene
Purpose Consequently to the principle that photoreceptors have to be at a very precise development stage to be successfully transplanted (MacLaren 2006), we are trying to mimic this development stage in vitro using retinal stem cells. The latter were isolated from the newborn mouse retina, derived from the radial glia population, and were previously isolated and characterized in our laboratory. We developed a protocol to commit these cells to the photoreceptor fate, but even if the percentage of cells expressing photoreceptor markers is high (30%), the differentiation process is incomplete so far (Merhi‐Soussi 2006). Methods To ameliorate photoreceptor differentiation, we hypothesized that the Notch pathway may interfere with this process by either promoting glia commitment, or maintaining an undifferentiated state. We are thus using a gamma‐secretase inhibitor (DAPT), which inhibits Notch activation, during the in vitro differentiation process. Results The constant presence of DAPT i) leads to a 233% increase in peripherin/RDS‐positive (photoreceptor marker) cells, compared to controls (no DAPT, n=3, P<0.02) along with a 68% decrease in GFAP‐ positive cells (n=3, P<0.04), ii) modifies the ratio between uni‐/bi‐ (23%) and multi‐ (77%) polar peripherin/RDS‐positive cells to 45% and 55%, respectively, and iii) reduces by 50% the total cell number during the whole differentiation process. Conclusion We are now exploring whether this reduction in total cell number is due to inhibition of cell proliferation or to cell death and whether photoreceptor differentiation is promoted instead of glial induction. Such protocol may help to better mimic photoreceptor development, but this needs to be confirmed by genomic and proteomic profile analyses.