Abstract
Purpose: :
Grafted cells normally have limited ability to survive and integrate into the adult host retina following transplantation. We showed previously that transplanted cells integrated robustly and extended longer neurites in the host retina that was pre–treated with gliotoxin – alpha amino adipate, compared to those in the control retina (ARVO, 2004). However, it remains unknown whether grafted cells differentiate and express appropriate markers after transplantation. Here we ask whether transplanted retinal progenitors integrate and differentiate appropriately in the host retina.
Methods: :
Gliotoxin (0.5 mg/ml) or saline was injected subretinally into the host retina of adult wild–type mice at 2 days before transplantation. Donner retinal cells were isolated from neonatal (P0–2) mice carrying an EGFP transgene, and cells suspension was injected into the subretinal space of the host retina. Three weeks after, retinal cross–sections were prepared and subjected to immunostaining for various retinal cell makers, including GFAP (glial cells), Brn3b (retinal ganglion cells), PKCα (bipolar cells), Rhodopsin (rod photoreceptor). The numbers of EGFP+ cells migrated to different cell layers and expressed various retinal cell markers were counted.
Results: :
EGFP+ cells migrated to different cellular layers and expressed various retinal cell markers, including GFAP and Brn3b. Interestingly, the majority of them localized to the outer nuclear layer (ONL), and approximate 80% of those migrated to the ONL expressed mature photoreceptor marker, Rhodopsin.
Conclusions: :
Our results demonstrate that transplanted cells can migrate and differentiate appropriately into various retinal neurons, including mature photoreceptor, in vivo. Manipulating host glial cell property with gliotoxin before transplantation may promote the success of neural transplantation/replacement therapy.
Keywords: transplantation • photoreceptors • retina