Human Embryonic Stem Cells --- The Most Positive Stem Cells

San Diego Regenerative Medicine Institute and Xcelthera announce the publication of Dr. Parsons’ original research, titled “The Dynamics of Global Chromatin Remodeling are Pivotal for Tracking the Normal Pluripotency of Human Embryonic Stem Cells”. Pluripotent human embryonic stem cells (hESCs) have the unconstrained capacity for long-term stable undifferentiated growth in culture and unrestricted developmental capacity. Packaging of the eukaryotic genome into chromatin confers higher order structural control over maintaining stem cell plasticity and directing differentiation. We recently reported the establishment of a defined culture system for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards functional lineages for cell-based therapies. To unveil the epigenetic mechanism in maintaining the epiblast pluripotence of hESCs, in this original study of Dr. Parsons supported by the National Institutes of Health, the global chromatin dynamics in the pluripotent hESCs maintained under the defined culture were examined. This study shows that the genomic plasticity of pluripotent hESCs is enabled by an acetylated globally active chromatin maintained by Oct-4. The pluripotency of hESCs that display normal stable expansion is associated with high levels of expression and nuclear localization of active chromatin remodeling factors that include acetylated histone H3 and H4, Brg-1, hSNF2H, HAT p300, and HDAC1; weak expression or cytoplasmic localization of repressive chromatin remodeling factors that are implicated in transcriptional silencing; and residual H3 K9 methylation. A dynamic progression from acetylated to transient hyperacetylated to hypoacetylated chromatin states correlates with loss-of-Oct4-associated hESC differentiation. RNA interference directed against Oct-4 and HDAC inhibitor analysis support this pivotal link between chromatin dynamics and hESC differentiation. These findings reveal an epigenetic mechanism for placing global chromatin dynamics as central to tracking the normal pluripotency and lineage progression of hESCs. This original research article of Dr. Parsons supported by the National Institutes of Health was published in Journal of Anatom. Physiol Special Issue on Stem Cell Biology.


Human embryonic stem cells (hESCs) are not only pluripotent, but also incredibly stable and positive, as dissected by this Dr. Parsons’ research article that only the positive active factors not the negative repressive factors can be found in hESCs. The normality and positivity of hESCs also differentiate hESCs from any other stem cells, such as the induced pluripotent stem cells (iPS cells) reprogrammed from adult cells. The iPS cells are made from adult cells, therefore, iPS cells carry many negative repressive factors of adult cells that hESCs do not have. The opponents of hESC research invented iPS cells and have been trying to make iPS cells sound the same as hESCs so they can take public funds & tax dollars away from stem cell research. However, iPS cells are not the same as hESCs. Those opponents of hESC research are telling the public that iPS cells have the similar gene expression pattern as hESCs, so they are the same. However, they did not tell the public that the most aggressive cancer cells also have the similar gene expression pattern as hESCs. It is those methods used by the opponents of hESC research that could not detect the differences.

The difference between iPS cells and hESCs is like the difference between a 90 year-old and a 1 year-old. The difference between iPS cells and hESCs is like the difference between CIRM (California Institute for Regenerative Medicine) and Proposition 71 (Prop71). CIRM has been complaining that they have not got much positive publicity. Perhaps, it is because they have not followed the law and regulations to fund the most positive cells on this planet --- the human embryonic stem cells. The law requires CIRM to give Prop71 funds to the most positive hESCs, however, CIRM has been defying the law to fund those negative cells, WYDIWYG (What You Do Is What You Get).


Finally, we’d like to thank our readers for the more than 700 hundreds comments to our 1^st post “iPS cells or man-made junk”, we are overwhelmed by your positive responses.