Friday, June 5, 2009
Pluripotent stem cells created...from pigs?!
Well, here's a fascinating discovery in the already fascinating world of stem cell development, and it might be useful (although admittedly a bit farfetched) down the road for that pesky swine flu that's all the rage. Scientists working in the stem cell lab at the Shanghai Institute of Biochemistry and Cell Biology have successfully induced pluripotent stem cells from the reprogramming of cells in a pig's ear and bone marrow. This is the first report of successful ungulate (animals with hooves) pluripotent stem cells.
The pluripotent stem cells were created with lentiviral vectors that expressed the four genes (Oct4, Sox2, c-Myc, and Klf4) that were used previously by Takahashi and Yamanaka in 2006 to induce pluripotent stem cells from human somatic cells. Subsequent tests confirmed that these cells were indeed stem cells, as they could differentiate into the three cell types that constitute an embryo -- endoderm, mesoderm, and ectoderm.
While the findings are in a very early stage of development, Dr. Xiao, the head of the stem cell lab, remains optimistic about the high potential of these reprogrammed stem cells; he believes that pigs could become donors of organs for human transplantation and their stem cells induced to mimic human disease so as to test therapies without requiring risky human testing. The ungluate pluripotent stem cells could also potentially be used to combat swine flu. If there is a gene that inhibits swine flu activity in pigs, it could be introduced by these stem cells, thus creating a pig resistant to swine flu.
Now I know that we do all sorts of ridiculous things to animals in the name of science, but I can't be the only one disturbed by the implications purported by Dr. Xiao. While his team's breakthrough could be a step forward in alleviating the human organ deficit experienced by hopeful transplant patients, the idea of treating pigs like disposable organ houses seems to me an unsettling precedent for future developments in stem cell technology. Furthermore, such ideas are much farther into the future than I think Dr. Xiao lets on. While pig organs are similar to humans, they are not the same -- there has to be negative health consequences that we cannot possibly forsee without trying out this type of transplant. Stem cell technology in general seems to continually lie at the boundary of medical ethics, so it will be interesting to see how scientists and the general public move forward with developments like these.
article link: http://news.bbc.co.uk/1/hi/health/8078996.stm
link to study: http://jmcb.oxfordjournals.org/cgi/content/full/mjp003v1