Stem Cell Digest
Scan these headlines for latest news about stem cells: the unethical kind (human embryonic, ESC) and the ethical kind (adult, induced pluripotent, iPSC).
The origin of stem cells (U of Freiburg). A protein in plant embryos prevents certain cells from differentiating, allowing them to keep their potential for later development. “This means that plants follow similar strategies in the process of stem cell development as found in animals.”
Mobile elements control stem cell potency (Science Magazine). What keeps both ESCs and iPSCs from becoming totipotent, able to differentiate into every kind of body cell? It’s a small, noncoding RNA, researchers found, along with a set of transposable elements. See full paper in same issue of Science Magazine.
Two factor-based reprogramming of rodent and human fibroblasts into Schwann cells (Nature Communications). Researchers found a new way to induce skin cells into the progenitors of Schwann cells the myelinate nerve fibers. “Generating iSCs through direct conversion of somatic cells offers opportunities for in vitro disease modelling and regenerative therapies.”
Induced pluripotent stem cells don’t increase genetic mutations (Medical Xpress). Good news about iPSCs – they are not more mutation-prone than ESCs. A study by NIH scientists “suggests that iPSCs do not develop more mutations than cells that are duplicated by subcloning” (an iPSC-generating technique). “These findings suggest that the question of safety shouldn’t impede research using iPSC.”
Developmental stage-dependent effects of cardiac fibroblasts on function of stem cell-derived engineered cardiac tissues (Nature Scientific Reports). Tinkering with mouse embryonic stem cells may be legitimate to understand development, but such studies may lead to ethical issues with ESCs.
Human embryonic and induced pluripotent stem cells maintain phenotype but alter their metabolism after exposure to ROCK inhibitor (Nature Scientific Reports). Rho kinase (ROCK) exposure has similar effects on ESCs and iPSCs. This is another good thing to know; ESCs don’t have an advantage in these cases.
Heart attack treatment might be in your face (Medical Xpress). Make a happy face for your heart health. “Researchers at the University of Cincinnati (UC) have received $2.4 million in federal funding to pursue research on a novel cell therapy that would repair heart damage using modified cells taken from the patient’s own facial muscle,” avoiding rejection and tumor formation.
Reprogramming Malignant Cancer Cells toward a Benign Phenotype following Exposure to Human Embryonic Stem Cell Microenvironment (PLoS One). The embryo is known to be a safe, anti-tumor environment. While these experiments look promising, it’s not clear that human embryos are required. The factors that contribute toward tumor reduction in the embryonic environment might be available in adult stem cells.
Therapeutic microparticles functionalized with biomimetic cardiac stem cell membranes and secretome (Nature Communications). This interesting paper combines iPSC knowledge with biomimetics. The abstract is worth quoting in full, as it represents a possible breakthrough in treatment options. Notice the initial praise for iPSC potential.
Stem cell therapy represents a promising strategy in regenerative medicine. However, cells need to be carefully preserved and processed before usage. In addition, cell transplantation carries immunogenicity and/or tumourigenicity risks. Mounting lines of evidence indicate that stem cells exert their beneficial effects mainly through secretion (of regenerative factors) and membrane-based cell–cell interaction with the injured cells. Here, we fabricate a synthetic cell-mimicking microparticle (CMMP) that recapitulates stem cell functions in tissue repair. CMMPs carry similar secreted proteins and membranes as genuine cardiac stem cells do. In a mouse model of myocardial infarction, injection of CMMPs leads to the preservation of viable myocardium and augmentation of cardiac functions similar to cardiac stem cell therapy. CMMPs (derived from human cells) do not stimulate T-cell infiltration in immuno-competent mice. In conclusion, CMMPs act as ‘synthetic stem cells’ which mimic the paracrine and biointerfacing activities of natural stem cells in therapeutic cardiac regeneration.
Small RNA-directed epigenetic programming of embryonic stem cell cardiac differentiation (Nature Scientific Reports). These scientists tinkered with mouse ESCs to get them to differentiate into cardiac cells via small RNAs. Again, it’s not clear that ESCs would be better than iPSCs for this, if it is ever translated to human trials.
Repair of bone defects with prefabricated vascularized bone grafts and double-labeled bone marrow-derived mesenchymal stem cells in a rat model (Nature Scientific Reports). Scientists tested the ability of stem cells from bone marrow to repair bone defects in rats. Five groups of rats with different applications showed varying degrees of success.
Revolutionary approach for treating glioblastoma works with human cells: Researchers reach critical milestone for treating brain cancer (University of North Carolina at Chapel Hill). Median survival for this kind of brain cancer is only 18 months. This exciting announcement may lead to clinical trials in about two years, the article says.
In a rapid-fire series of breakthroughs in just under a year, researchers at the University of North Carolina at Chapel Hill have made another stunning advance in the development of an effective treatment for glioblastoma, a common and aggressive brain cancer. The work, published in the Feb. 1 issue of Science Translational Medicine, describes how human stem cells, made from human skin cells, can hunt down and kill human brain cancer, a critical and monumental step toward clinical trials — and real treatment.
Cell population structure prior to bifurcation predicts efficiency of directed differentiation in human induced pluripotent cells (PNAS). Researchers at the University of Washington are finding better ways to speed up differentiation of iPSCs toward the desired target cell.
Stem cell transplants may induce long-term remission of multiple sclerosis (Medical Xpress). Here comes another exciting promise for adult stem cells – this time for multiple sclerosis sufferers: “New clinical trial results provide evidence that high-dose immunosuppressive therapy followed by transplantation of a person’s own blood-forming stem cells can induce sustained remission of relapsing-remitting multiple sclerosis (MS), an autoimmune disease in which the immune system attacks the central nervous system.”
Clinic claims it has used stem cells to treat Down’s syndrome (New Scientist). Sadly, some international clinics are taking advantage of the stem cell hype to make false claims about cures for various conditions. You don’t treat Down syndrome with stem cells, but fakers in India are giving parents of Downs kids with this evidence-free false hope.”The use of stem cells doesn’t make sense and may place the babies at considerable risk.”
Update 2/11/17: Amelioration of experimental autoimmune encephalomyelitis through transplantation of placental derived mesenchymal stem cells (Nature Scientific Reports). Placental derived mesenchymal stem cells (PMSCs) might not only help treat MS, but also encephalomyelitis. Extra good news is that these adult stem cells can be used instead of embryonic stem cells (EMSCs). “Moreover, both PMSCs and EMSCs had the ability to migrate into inflamed tissues and express neural–glial lineage markers. These findings suggest that PMSCs may replace EMSCs as a source of cells in MS stem cell therapy.”
We hope this list will prove a valuable resource for those seeking news about medical ethics, stem cell treatments, and molecular biology.