14 June 2012

Restoring Vision Through Stem Cell Regeneration of Retina and Optic Cup of the Eye


This is a human ES cell-derived optic cup generated in our self-organization culture (culture day 26). Bright green, neural retina; off green, pigment epithelium; blue, nuclei; red, active myosin (strong in the inner surface of pigment epithelium).
Credit: Nakano et al. Cell Stem Cell Volume 10 Issue 6
Stem cells are cells that have the ability to form into most types of biological cells in the body.

In terms of human stem cells, these cells can be made into various human cells and tissues. This technology has great potential to treat otherwise untreatable diseases and conditions. Stem cells can repair and even replace diseased cells in organs and tissues. It can even assist in organ regeneration.

Advances in stem cell research has expanded the procurement of stem cells. During the early years of stem cell study, the cells were harvested from human embryos which have caused it to be a moral issue since embryos can develop into a human fetus.

Today there are processes in gathering stem cells that generate four types of stem cells, these are:
  1. Embryonic Stem Cell
  2. Nuclear Transplant Stem Cell
  3. Parthenote Stem Cell
  4. Induced Stem Cell
The first three types require a fertilized egg cell to form. Induced stem cells are generated by modifying the genetic structure of a normal cell to activate its stem cell properties.

Scientists see new hope for restoring vision with stem cell help

Human-derived stem cells can spontaneously form the tissue that develops into the part of the eye that allows us to see, according to a study published by Cell Press in the 5th anniversary issue of the journal Cell Stem Cell. Transplantation of this 3D tissue in the future could help patients with visual impairments see clearly.

"This is an important milestone for a new generation of regenerative medicine," says senior study author Yoshiki Sasai of the RIKEN Center for Developmental Biology. "Our approach opens a new avenue to the use of human stem cell-derived complex tissues for therapy, as well as for other medical studies related to pathogenesis and drug discovery."

Video: Stem Cell and Blinding Corneal Disease


During development, light-sensitive tissue lining the back of the eye, called the retina, forms from a structure known as the optic cup. In the new study, this structure spontaneously emerged from human embryonic stem cells (hESCs)—cells derived from human embryos that are capable of developing into a variety of tissues—thanks to the cell culture methods optimized by Sasai and his team.

The hESC-derived cells formed the correct 3D shape and the two layers of the optic cup, including a layer containing a large number of light-responsive cells called photoreceptors. Because retinal degeneration primarily results from damage to these cells, the hESC-derived tissue could be ideal transplantation material.

Beyond the clinical implications, the study will likely accelerate the acquisition of knowledge in the field of developmental biology. For instance, the hESC-derived optic cup is much larger than the optic cup that Sasai and collaborators previously derived from mouse embryonic stem cells, suggesting that these cells contain innate species-specific instructions for building this eye structure. "This study opens the door to understanding human-specific aspects of eye development that researchers were not able to investigate before," Sasai says.

The anniversary issue containing Sasai's study will be given to each delegate attending the 2012 ISSCR meeting in Yokohama, Japan. To highlight the ISSCR meeting and showcase the strong advances made by Japanese scientists in the stem cell field, the issue will also feature two other papers from Japanese authors, including the research groups of Akira Onishi and Jun Yamashita. In addition, the issue contains a series of reviews and perspectives from worldwide leaders in stem cell research.

RELATED LINKS

Cell Press
Cell Stem Cell
RIKEN Center for Developmental Biology
International Society for Stem Cell Research (ISSCR)
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