Researchers in the UK have developed a method which they hope will lead to more effective retinal transplants in the future.
A team from the Department of Genetics at the University College London Institute of Ophthalmology research team in the UK has found that insulin-like growth factor (IGF1) impacts cell transplantation of photoreceptor precursors by manipulating the retinal recipient microenvironment, enabling better migration and integration of the cells into the adult mouse retina.
The study, published in the current issue of Cell Transplantation (21:5), is a major step forward, the experts claim.
Dr Rachael A Pearson, study co-author and a member of the department, explained that photoreceptor death is an irreversible process and represents one of the largest causes of untreatable blindness in the developed world.
"Stem cell replacement therapy offers a novel strategy for retinal repair, but since it is likely that a large number of cells would be needed to restore vision, enhancement of the process is needed," she added.
In the study, the experts used adeno-associated viral vectors (AAVs) to introduce three growth factors previously reported to play a role in photoreceptor development - IGF1, fibroblast growth factor (FGF2) and ciliary neurotrophic factor (CNTF) - into the retinas of adult mice.
Three weeks after transplantation, the number of integrated, differentiated photoreceptor cells present in the growth factor-treated retinas were compared to the untreated controls, with the researchers noting that all three growth factors were present during retinal development and all have been shown to affect photoreceptor differentiation.
The researchers concluded that it was possible to manipulate the environment of the recipient retina for photoreceptor cell transplantation using viral vectors, and that IGF1 provided a greater response.
Commenting on the research, Dr John Sladek, professor of neurology and paediatrics at the University of Colorado School of Medicine, said the study demonstrates that, by modifying the environment, growth factors impact cell transplantation survival.
"While this study focused on the retina, growth factors also are believed to alter cell transplantation and survival in other brain regions which means that these findings should lead to more research on other serious neurological disorders," he added.