Trasplante de tejido retiniano y de células progenitoras retinianas: una promesa terapéutica para pacientes con enfermedad de la retina / Retinal tissue transplantation and retinal progenitor cells: a therapeutic promise for patients with retinal disease

La retinopatía diabética, la degeneración macular relacionada con la edad y la retinitis pigmentosason las enfermedades retinianas más frecuentes en todo el mundo. A pesar de no contar consuficientes estudios que demuestren resultados funcionales positivos en cuanto a recuperar lafunción visual, el uso de células madre y células progenitoras retinianas y el trasplante de retinafetal parecen bastante promisorios. Hasta el momento no se han podido obtener resultadospositivos sobre la funcionalidad de las células trasplantadas, pero sí se ha demostrado que elprocedimiento para transferir el tejido retiniano es seguro y confiable. Aún no se ha intentadoen seres humanos el trasplante de células progenitoras retinianas, pero dicho trasplante ha dadoresultados satisfactorios en modelos múridos. Los estudios con células progenitoras retinianashan logrado demostrar en modelos múridos que se activan y expresan los fotorreceptores. Existenalgunas barreras de disponibilidad para el uso de células progenitoras retinianas, que se debensuperar con el fin de adelantar estudios que permitan aumentar las posibilidades de integracióny diferenciación de dichas células hacia fotorreceptores.

Retinal tissue transplantation and retinal progenitor cells: A therapeutic promise for patients with retinal diseaseWorldwide, diabetic retinopathy, age-related macular degeneration, and retinitis pigmentosahave the highest incidence rate among retinal diseases. Despite the lack of enough trialsdemonstrating positive functional results on eyesight recovery, the use of stem cells, retinalprogenitor cells, and fetal retinal tissue transplantation seem very promising. So far positiveresults on the functionality of the transplanted cells have not been obtained. However, the safetyand reliability of the procedure to transfer retinal tissue have been demonstrated. Transplantationof retinal progenitor cells has not been tried on human beings, but there have been satisfactory results with it in murine models. Trials with retinalprogenitor cells have demonstrated activation andexpression of photoreceptors in murine models. Somebarriers of availability exist for the use of retinalprogenitor cells that must be overcome in order tocarry out studies to increase the possibility of theirintegration and differentiation towards photoreceptors.

Strategies to promote optic nerve regeneration

Damage to the adult mammalian optic nerve (ON) usually results in the degeneration of the ON and death of retinal ganglion cells (RGCs), leading to permanent loss of visual functions. New strategies, especially the transplantation of a peripheral nerve (PN) to the retina or transected ON, have been created to promote the neuronal survival and axonal regeneration of axotomized RGCs. In this review, we focus on how a PN and other factors are used to overcome the unfavorable extrinsic CNS environment and the lack of trophic factors, and upregulate the intrinsic growth potential of the axotomized neurons since recent studies suggest that the lack of intrinsic growth potential in the CNS neurons is also an important factor contributing to the failure of CNS regeneration.