Cone photoreceptors in laminated retinal transplants

Abstract

ABSTRACT.Purpose: To investigate the contents of green-and blue-sensitive cone photoreceptors in laminated rabbit retinal transplants. Methods: Eleven rabbits each received a sheet of embryonic neuroretina into the subretinal space in one eye. Vitrectomy was used in the procedure and properly polarized flat transplants were placed on the host pigment epithelium. After 17-309 days the transplants were examined immunohistochemically with specific antibodies against COS-1 (green-sensitive cones) and OS-2 (blue-sensitive cones). Results: All grafts displayed normal lamination with well developed photoreceptor outer segments apposed to the host retinal pigment epithelium. Occasionally, rosettes were found at the transplant edges. Both COS-1 positive and OS-2 positive cones were detected. In the laminated part of the grafts, COS-1 positive cones were more numerous than OS-2 positive ones. In the rosetted parts of the transplants the relationship between the cones was reversed. Conclusion: Full-thickness embryonic rabbit retinal transplants develop into laminated retinas with well-developed photoreceptor outer segment. Both greenand blue-sensitive cone photoreceptors are present and the ratio between the two cone types is the same as in the normal adult rabbit retina.

Bone Marrow‐Derived Stem Cells Can Differentiate into Retinal Cells in Injured Rat Retina

“…Putative progenitors of retinal cells contained in the embryonic retina survived and differentiated into retinal cells in the transplanted eyes [18]. Embryonal retinas transplanted into the subretinal space survived in the host eyes [19][20][21]. In the above reports, retinal tissue was transplanted, and it is, therefore, difficult to apply these techniques to autotransplantation in clinical treatment.…”

“…On the other hand, neural stem cells can generate hematopoietic cells in vivo, indicating that neural precursor cells are not restricted to the differentiation of neural-lineage cells [15]. There are many studies of retinal transplantation using the newborn or the embryonic Stem Cells ® Original Article brain [16,17] and retina-derived neural cells [18][19][20][21]. Moreover, hippocampus-derived neural stem cells have been shown to differentiate into neural-forming cells, which are then incorporated into the injured retina [22][23][24][25].…”

Outer Retinal Tubulation

“…This peculiar retinal phenotype is seen not only congenitally in retinal dysplasia but also in mouse models of Pax6 overexpression 1 and in models of retinal transplantation. 2,3 The phenotype can also be acquired, as seen in rats in which protein prenylation was inhibited by intravitreal statin injection 4 and in patients with retinitis pigmentosa. 5,6 With low-resolution OCT imaging, ORT may be easily mistaken for intraretinal or subretinal fluid.…”