Wednesday, August 26, 2009

Retinal cells from iPS cells… no need for embryos

Remember the excitement about ESC being used to create retinal cells? Big headlines amongst the excitable. Now, of course, the Aug. 24 edition of the Proceedings of the (US) National Academy of Sciences shows the creation of human retinal cells from the superior-in-every-way iPS cell derived from skin.


Says the University of Wisconsin-Madison School of Medicine scientist: "This is an important step forward for us, as it not only confirms that multiple retinal cells can be derived from human iPS cells using the Wisconsin approach, but also shows how similar the process is to normal human retinal development."


Here is the report in Science Daily:

Retina Cells Created From Skin-derived Stem Cells


"The Wisconsin team took cells from skin, turned them back into cells resembling embryonic stem cells, then triggered the development of retinal cell types.

"Because the group was successful using the iPS cells, they expect this advance to lead to studying retinal development in detail and treating conditions that are genetically linked. For example, skin from a patient with retinitis pigmentosa could be reprogrammed into iPS cells, then retina cells, which would allow researchers to screen large numbers of potential drugs for treating or curing the condition.

"The team had similar success in creating the multiple specialized types of retina cells from embryonic stem cells, underscoring the similarities between ES and iPS cells."


'Similarities' indeed between ES and iPS cells – they are functionally identical - but there are vital dissimilarities in the relative usefulness of iPS and ESC:

  • only iPS matches the patient, so only iPS is useful for genetic research and drug tailoring for that patient;
  • only iPS could (if any pluripotent cell is ever considered safe) be used in transplants of retinal cells without the need for immune suppression.
  • only the ugly science of ESC research involves strip-mining an embryonic human for its useful bits.


And as per our earlier Blog on the Big Deal about ESCs producing retinal cells:

  • For that matter, why use either ESC or iPS when you can use adult stem cells (ASC)? We already have reports of the capacity of ASCs to generate the same retinal cells generated by ESCs in this 'breaking news'. Again, there is not one but TWO huge clinical differences. ASCs, like iPS cells, match the patient – but ESCs are foreign. Further, ASCs alone are free from the tumour risk inherent in ESC / iPS cells. Which type of cell would you, the patient, prefer to have in the back of your eye?