Riken claims world first in forming three dimensional retinas from ES cell, offering hope to degeneration treatments. 2011.4.7 02:00
A research team at Riken succeeded for the first time in the world, in forming three dimensional retina tissues from mice embryonic stem cell (ES cell). The aim is to apply in human such as treatment of retinal pigment degeneration as it is also possible with human induced pluripotent stem cell (iPS cell). The finding was published on a British science journal “Nature” dated 7th.
Retinas are an important structure where lights are detected and retinal pigment degeneration can lead to blindness. They do not regenerate naturally; therefore, there is a high expectation on the regenerative medicine using stem cells.
The research team made a block of ES cells and left it in the culture solution. By day 9~10, formation of optic cup, which is an archetype of an eye, was confirmed. On day 24, approximately 2mm of neural retina, out of the whole retina, was formed. This is a layered structure of 6 kinds of main cell types.
According to Deputy Unit Leader Eiraku at Riken, applying to human should be technically possible in a few years.
Prof Yamanaka and team at Kyoto Uni produce cancer risk reduced iPS cells
2011.4.4 08:37
A team at Kyoto University, headed by Professor Yamanaka, found an effective method of producing an induced pluripotent stem cell (iPS cell) using the cyclic gene, epithermal plasmid. Their finding was published on an American science journal Nature Method online version dated April 3rd.
They succeeded in producing 30 blocks of iPS cells per 100,000 cells by inducing plasmids, inserted with 6 genes such as OCT4 and L-MYC, into a fibroblast.
They also analysed the HLA (type of leukocyte) of cell strains from approximately 100 donors who were registered in a “pulp cell bank”. The bank, which is run by Gifu University, stores stem cells from teeth extracted at treatments. Two strains were found to be less likely to cause rejection when transplanted into another person. They were induced with the same epithermal plasmids to produce iPS cells.
Lecturer Okita said, “It may be quite reasonable to establish an iPS cell bank. We want the safety to be self evident.” The initially published method of producing iPS cells by Prof Yamanaka is more effective. However, there has been an indication that the retrovirus used in inducing carry the risk of turning cells cancerous.
Kyoto Uni makes iPS cell without damaging the gene 2011.4.4 08.00
A team at Kyoto University, headed by Lecturer Okita and Prof. Yamanaka, developed a method which does not use the virus nor damage the cell chromosome when producing an iPS cell (induced pluripotent stem cell), in order to heighten its safety. It was made possible by improving a previous method using DNA, developed in 2009 in USA, and raising its effectiveness. The finding will be presented on an American science journal Nature Methods online version on 4th. iPS cell production, using a certain virus, has the potential to damage the genes that are originally present and turn it cancerous because the virus actually induces the genes into a cell chromosome.
An American research group had previously developed a method of inducing necessary genes for iPS cells into a unique DNA that replicates outside the chromosome. Okita and the team changed the combination of the types of genes induced in this method and found it to be less effective than using virus, however, more effective than the American group’s result.
The team at Kyoto University researched the genes related to rejections. They used dental pulps of persons, who have the type of gene that enables transplantation to many people, and produced iPS cell using this method. As a result, the team says that iPS cell, less expected to see rejection in 20% of the Japanese population, has been produced.
