July 21, 2013

expert reaction to photoreceptor transplantation into retinas of mice from mouse embryonic stem cells

A study published in Nature Biotechnology has shown that photoreceptor cells, grown in the lab from mouse embryonic stem cells, can be transplanted into mice retinas and successfully integrate there, illustrating that some types of blindness might be responsive to cell therapy.

Professor Chris Mason, Chair of Regenerative Medicine Bioprocessing, UCL, said:

“Eye disorders are proving to be excellent early targets for stem cell therapies including successfully restoring patients’ corneas, on-going clinical trials for age-related macular degeneration, and now proof of concept in mice that damaged retinas might be regenerated.

“The big challenge is whether this 3-D culture approach will work in patients – restoring the sight for the ‘three blind mice’ may be far easier than for the ‘farmer’s wife’. Before human clinical trials can commence, the mouse model will require significant optimisation, for example, increasing the efficiency of new photoreceptors to connect with the damaged retina. However, there is no doubt that this breakthrough, either directly as the basis of a future cell therapy, or indirectly by expanding our knowledge, will significantly contribute to the fight against blindness.”

Dr Dusko Ilic, Reader in Stem Cell Science, Kings College London, said:

“This paper is an important step forward in technology.  Employing 3D culture system in cell differentiation is becoming recently more and more popular and it is yielding better results than standard culture methods. However, this study is only one small step on a long way to clinical trials and eventually therapeutic use in humans. We should not get overenthusiastic. In this particular study only 0.3% of ESC-derived photoreceptors integrate into the retina of an animal model.  As the authors stated in the abstract: “This study shows conclusively that ESCs can provide a source of photoreceptors for retinal cell transplantation.”

 Dr Marcelo Rivolta, Reader in Sensory Stem Cell Biology, University of Sheffield, said:

“’This paper represents a huge leap in the efforts to treat blindness. It shows that photoreceptors, produced afresh in a test tube and from a renewable source, can be effectively transplanted into the damaged retinas of adult mice. The absence of a natural regenerative response in our sensory senses prevents them from healing, but this limitation could be overcome by the use of embryonic stem cells. This work elegantly illustrates how it can be done for the eye and teaches us lessons that could be translated to other sensory organs.”

Professor Daniel Brison, Co-Director of the North West Embryonic Stem Cell Centre, Central Manchester University Hospitals NHS Foundation Trust, said:

“This is a very exciting study which demonstrates good progress towards the goal of using human embryonic stem cells for the treatment of disease.  One of the major challenges for stem cell therapies is to develop methods for the tissue engineering of complex 3D structures from cells in a dish, as this study describes.   The UK has recently produced a number of clinical grade human embryonic stem cell lines at the highest standards available anywhere in the world, and so UK scientists will be well placed to make progress with these medical applications.”

‘Photoreceptor precursors derived from three-dimensional embryonic stem cell cultures integrate and mature within adult degenerate retina’ by Anai Gonzalez-Cordero et al. has been published in Nature Biotechnology.