Selective transplantation of rods delays cone loss in a retinitis pigmentosa model.
BACKGROUND
Rod-cone retinal degenerations (retinitis pigmentosa) are typified by initial rod loss followed by secondary cone death. Rod death, predominantly caused by gene mutations expressed specifically in these cells, induces scotopic vision loss. Cone death, the overriding cause of blindness, has no current explanation. Disease progression and preliminary data suggest that cone survival depends on rods.


OBJECTIVE
To establish whether rod transplantation into mutant rodless retinas could halt cone loss.


METHODS
We transplanted pure sheets of rods isolated from normal-sighted mice into the subretinal space of recipient retinal degeneration mice lacking rods but possessing approximately 30% residual cones. Control animals were unoperated on or grafted with inner retinal cells from young normal donors, entire retinas from aged retinal degeneration mice, or gelatin. Two weeks after surgery, we quantified by an unbiased method the numbers of host retinal cones after immunolabeling with specific markers.


RESULTS
Only mice receiving rod-rich transplants demonstrated statistically significant greater cone numbers, with rescue of 40% of host cones normally destined to die during this period.


CONCLUSIONS
Cone survival depends specifically on rods.


CONCLUSIONS
Such findings indicate that transplantation of rods could limit loss of cones, thus preserving useful vision in human retinitis pigmentosa. Arch Ophthalmol. 2000;118:807-811
Mohand-Said
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Laboratoire de Physiopathologie Cellulaire et Moléculaire de la Rétine, EMI 9918 INSERM, Clinique Médicale A, Hôpitaux Universitaires de Strasbourg, 1 Place de l'Hôpital, 67091 Strasbourg Cédex, France.
Hicks
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D
Dreyfus
H
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Sahel
J A
JA
D000818:Animals; D015415:Biomarkers; D002452:Cell Count; D002470:Cell Survival; D017690:Cell Transplantation; D004195:Disease Models, Animal; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D012160:Retina / Q000601:surgery; D017949:Retinal Cone Photoreceptor Cells / Q000473:pathology*; D017948:Retinal Rod Photoreceptor Cells / Q000473:pathology / Q000637:transplantation*; D012174:Retinitis Pigmentosa / Q000473:pathology / Q000601:surgery*
D015415:Biomarkers