Stem cell research is an enormous field these days. Not a week goes by without the demonstration of some new advance, most of which now skate beneath the notice of the public, and yet as recently as ten years ago would have been major milestones in and of themselves. The wondrous becomes prosaic very quickly indeed in this age of rapid, revolutionary progress in biotechnology. The stem cell field is perhaps the only area of medical science important to human longevity that needs little help in meeting the goals needed to reverse the effects of aging on cell populations. Funding is easily raised, there are many researchers with the necessary skills and interest to participate, and the most obvious and lucrative applications for stem cell therapies involve treating degenerative conditions of aging. Researchers are thus set on a course that requires them to find out how to repair loss of stem cell function with age in order for these therapies to work effectively in old people.
Stem cell research is a shining example of a successful field of medical research. If we are to see meaningful progress in the other necessary portions of longevity science, however, aging research in general must grow to become as large and as energetic a field as stem cell science, and a research community that is just as motivated to find practical clinical therapies.
Here are some recent examples of progress in the ability to work with stem cells: a few steps forward among the hundreds presently underway.
[Researchers] looked at a certain protein, called MBD3, whose function was unknown. MBD3 had caught their attention because it is expressed in every cell in the body, at every stage of development. This is quite rare: In general, most types of proteins are produced in specific cells, at specific times, for specific functions. The team found that there is one exception to the rule of universal expression of this protein: the first three days after conception. These are exactly the three days in which the fertilized egg begins dividing, and the nascent embryo is a growing ball of pluripotent stem cells that will eventually supply all the cell types in the body. Starting on the fourth day, differentiation begins and the cells already start to lose their pluripotent status. And that is just when the MBD3 proteins first appear.
This finding has significant implications for the producing [induced pluripotent stem cells] for medical use. [Researchers] used viruses to insert the four genes but, for safety reasons, these are not used in reprograming cells to be used in patients. This gives the process an even lower success rate of only around a tenth of a percent. The researchers showed that removing MBD3 from the adult cells can improve efficiency and speed the process by several orders of magnitude. The time needed to produce the stem cells was shortened from four weeks to eight days. As an added bonus, since the cells all underwent the reprograming at the same rate, the scientists will now be able, for the first time, to actually follow it step by step and reveal its mechanisms of operation.
Scientists have succeeded in growing stem cells that have the ability to develop into two different types of cells that make up a healthy pancreas. The research team [have] isolated and grown stem cells from the pancreases of mice using a 3-D culture system previously developed by the scientists. The results [could] eventually lead to ways to repair damaged insulin-producing beta cells or pancreatic duct cells.
In the study, the pancreases of mice were altered in a way that makes duct cells proliferate and differentiate. Some cells in this new population were stem cells that were capable of self-renewal. The scientists were able to culture these cells to give rise to large numbers of pancreatic cells or tiny clumps of tissue referred to as organoids.
Scientists have succeeded in generating new stem cells in living mice and say their success opens up possibilities for the regeneration of damaged tissue in people with conditions ranging from heart failure to spinal cord injury. The researchers used the same "recipe" of growth-boosting ingredients normally used for making stem cells in a petri dish, but introduced them instead into living laboratory mice and found they were able to create so-called reprogrammed induced pluripotent stem cells (iPS cells). "This opens up new possibilities in regenerative medicine. In principle, these partially dedifferentiated cells could [be] induced to differentiate to the cell type of choice inducing regeneration in vivo without the need of transplantation."
Efficient generation of competent vasculogenic cells is a critical challenge of human induced pluripotent stem (hiPS) cell-based regenerative medicine. Biologically relevant systems to assess functionality of the engineered vessels in vivo are equally important for such development. Here, we report a unique approach for the derivation of endothelial precursor cells from hiPS cells [and] an efficient 2D culture system for hiPS cell-derived endothelial precursor cell expansion.
With these methods, we successfully generated endothelial cells (ECs) from hiPS cells obtained from healthy donors and formed stable functional blood vessels in vivo, lasting for 280 days in mice. In addition, we developed an approach to generate mesenchymal precursor cells (MPCs) from hiPS cells in parallel. Moreover, we successfully generated functional blood vessels in vivo using these ECs and MPCs derived from the same hiPS cell line.
These data provide proof of the principle that autologous hiPS cell-derived vascular precursors can be used for in vivo applications, once safety and immunological issues of hiPS-based cellular therapy have been resolved. Additionally, the durability of hiPS-derived blood vessels in vivo demonstrates a potential translation of this approach in long-term vascularization for tissue engineering and treatment of vascular diseases.