Thursday, November 15, 2012

Guest blogger Alan Trounson — October’s stem cell research highlights

Each month CIRM President Alan Trounson gives his perspective on recently published papers he thinks will be valuable in moving the field of stem cell research forward. This month’s report, along with an archive of past reports, is available on the CIRM website.

Although this months full report showcases a couple interesting papers refining our understanding of stem cells in the brain, I want to focus this blog on something even more essential for life—eggs.

Two leading journals, Science and Nature, both published major papers in October on eggs. The article in Science detailed the work of a Japanese team that created viable mouse eggs by reprograming adult stem cells. This was an incredibly difficult feat. Eggs need to possess all the starting materials to begin to create an embryo, but they can only have one set of chromosomes including an X chromosome, unlike the two sets that would be in the initial embryo or stem cell, just like every other tissue in our bodies, except sperm of course that have a single set with either an X or Y chromosome. Eggs also need a special environment to nurture them to mature and be ready for fertilization. The stem cells this team used not only resulted in viable mouse pups, the cells also became grandparents, suggesting the offspring were pretty close to, if not completely normal.

The Nature paper describes a procedure that could allow mothers to avoid passing down certain genetic diseases to their children. About one in 5.000 people is born with a genetic disease not caused by errors in their chromosomes in their cells’ nucleus, but rather errors in the genes carried in structures within the cells called mitochrondria that generate energy for the rest of the cell. Gene variants in these mini-organelles and errors in their DNA have been linked to many rare diseases. But we only have one copy of each of these genes, because we only inherit the ones that were in the mitochondria of our mother’s eggs.

The research team from Oregon worked with human eggs and was able to produce genetically normal stem cell lines from eggs carrying mitochondrial mutations. They accomplished this feat by transferring the chromosomes from the nucleus of the original egg into donor eggs that had normal mitochondria.

The Oregon team predicted that the first human birth from using this procedure could come within three years. However, the Japanese team said that moving their work from the mouse model to human could take many years. Nonetheless, both projects have given us valuable new insight into an aspect of human development this is still shrouded in mystery, how normal eggs mature and begin to develop into an embryo. 

My full report is available online, along with links to my reports from previous months.


1 comment:

  1. Innocent Intrigue : Hans S. Keirstead at TEDxOrangeCoast

    Stem cells will fundamentally change the course of human disease and longevity, says Hans Keirstead.

    An internationally known stem cell expert, Hans Keirstead has pioneered stem cell programs at UC Irvine and California Stem Cell. He led his teams to develop a stem cell-based treatment for paralysis, that marked the first such stem cell-based clinical
    trial ever approved by a regulatory body, worldwide, with positive interim data in a Phase 1 clinical trial. Dr. Keirstead also helped develop a therapy for the treatment of ulcerative collitis and rheumatoid arthritis, that has successfully met primary endpoints in Phase II clinical trials. He developed a stem cell-based therapy for the motor neuron diseases ALS and spinal muscular atrophy that will soon enter clinical testing, and made headlines for creating a 3D retina from stem cells for the treatment of retinal diseases. More recently, is developing a stem cell-based treatment for late stage cancers, a technology that has met primary endpoints in Phase II clinical trials.

    About TEDx.
    TEDx was created in the spirit of TED's mission, "ideas worth spreading." The program is designed to give communities, organizations and individuals the opportunity to stimulate dialogue through TED-like experiences at the local level.