Abstract
Purpose: :
In retinal disease, such as retinitis pigmentosa, and after reattachment of detached retina, rod photoreceptor cells sprout neurites. We have demonstrated that activity of adenylyl cyclase (AC) contributes to sprouting by isolated salamander rod cells. We also reported that β-ionone, an opsin agonist, can stimulate AC activity through G protein in isolated rod cells in which opsin occurs along the inner segment and cell body (Alfinito and Townes-Anderson, 2002). In this study, we have tested whether β-ionone can induce sprouting by rod cells in cell culture and retinal tissue.
Methods: :
For cell culture, retinal cells were isolated from adult tiger salamanders, cultured for 3 days, and stained for rod opsin and phosphorylated cAMP-dependent transcription factor (pCREB), to analyze for neuritic growth and CREB activity respectively. For tissue culture, eyeballs with cornea, lens and iris removed, were cultured for 7 days, sectioned at 35 µm, and stained for opsin and propidium iodide to determine rod cell sprouting.
Results: :
β
Conclusions: :
β-ionone was able to increase the neurite outgrowth of isolated rods cell in culture, most likely through the pCREB signaling pathway stimulated by AC. Rod cell sprouting, similar to that observed in disease, was stimulated in intact retina by retinal detachment, which causes mislocalization of opsin, and opsin activation. This in vitro system of intact retina may provide a new way to study the mechanism behind such sprouting.
Keywords: photoreceptors • retinal degenerations: cell biology • plasticity