Stem Cells Back in the News with New Hopes and Discoveries
Stem cells were all the rage ten years ago, but news stories these days are less common. What’s new?
How your muscles form (Science Daily). It all begins with stem cells. “”In vertebrates, cells derived from stem cells, called myoblasts, first align with each other and come so close as to eventually touch and compress their cell membranes,” explains a researcher from the University of Montreal. The myoblasts fuse to create one large cell, but the precision work is not done. “To develop and also repair muscle, myoblasts have to perform their movements very carefully, the article goes on to say. “No false move is permissible, otherwise there will be defects.”
Scientists use patients’ own cells and materials to engineer fully personalized tissue implants of any kind (Phys.org). Scientists at Tel Aviv University report the implantation of a tissue derived from the patient’s own cells. This avoids the problem of tissue rejection:
The researchers extracted a small biopsy of fatty tissue from patients, then separated its cellular and a-cellular materials. While the cells were reprogrammed to become induced pluripotent stem cells—able to make cells from all three basic body layers, so they can potentially produce any cell or tissue the body needs to repair itself—the extracellular material was processed to become a personalized hydrogel. After combining the resulting stem cells and the hydrogel, the scientists successfully engineered the personalized tissue samples and tested the patients’ immune responses to them.
This promising technique may someday be used to repair hearts, spinal cords, eyes, intestines and other organs, using the patient’s own cells, as well as treat degenerative diseases like Parkinson’s disease. “We believe that the technology of engineering fully personalized tissue implants of any type will allow us to regenerate any organ with a minimal risk of immune response.”
Resting zone of the growth plate houses a unique class of skeletal stem cells (Nature). The growing tips of our bones have stem cells. A new class of stem cell was discovered that begins without stemness, but acquires stemness under a tighly controlled program.
Our findings unravel a type of somatic stem cell that is initially unipotent and acquires multipotency at the post-mitotic stage, underscoring the malleable nature of the skeletal cell lineage. This system provides a model in which functionally dedicated stem cells and their niches are specified postnatally, and maintained throughout tissue growth by a tight feedback regulation system.
A popular-level news item at Medical Xpress explains this, saying, “Unique type of skeletal stem cells found in ‘resting zone’ are actually hard at work.” They found something beautiful and hard-working in what they thought was a lazy hangout for cells:
The growth plate is composed of different layers, with the resting zone in the top layer. It’s long been thought that cells in the resting zone don’t divide, but Noriaki’s group discovered that some cells in the resting zone wake up and start to make rapidly dividing chondrocytes—cells that produce “beautiful” columns (that look like a stack of pancakes) and maintain bone growth.
Some of the cells in the resting zone go all the way from the top to the bottom layer of the growth plate, and some of them actually go through the growth plate and into the bone marrow cavity, creating osteoblasts (cells that make bone) and bone marrow stromal cells, which support blood cells.
Noriaki said he was surprised that the cells in the resting zone “weren’t just lazy and doing nothing, they’re very hardworking cells, they can occasionally wake up and keep making chondrocytes.”
Definitions for adult stem cells debated (Nature). The old dogma about stem cells was that they constitute a pool that remains potent through life, and differentiates after cell division. Now, as the previous article indicates, scientists are not so sure. It appears in more cases that non-stem cells can become stem cells. This article examines evidence from both sides of the debate.
Can Injecting Millions of Stem Cells into the Brain Treat Parkinson’s Disease? (Live Science). Rachael Rettner describes a clinical trial going on in Japan that hopes to treat Parkinson’s Disease with stem cells. This is the first trial of its kind with donated iPSCs (induced pluripotent stem cells). They injected 2.4 million of the cells into the left side of a man’s brain. If there are no bad consequences, they will try a similar treatment on his right side.
Researchers use burn victims’ own cells to regrow skin up to 30 percent quicker (Medical Xpress). The recent deaths from wildfires in California remind us all how quickly burns can maim and kill. In what promises great hope to burn victims, “University of Toronto researchers are planning to give burn victims live stem cells from their own burned skin in an effort to speed up recovery and increase their chances of surviving fires and industrial accidents.” Trials begin early next year. The discovery was serendipitous:
Until now, almost nobody thought of looking for viable cells in the burned skin itself, which is normally considered medical waste. When the U of T researchers began looking in the first pieces of discarded skin, they hoped to find even one living cell. They were exhilarated by the discovery of thousands of cells – in some cases up to one million cells.
Coming from the same location as the burn, these stem cells offer less chance of rejection and should produce fully functional skin, with sweat glands, flexibility and all.
“We also believe this will be better for quality of life: Itching and inability to sweat are big problems for burn patients. We believe if we use the stem cells from the very same organ, we’ll grow better skin.”
Using a patient’s own stem cells also won’t raise ethical issues, he says.
“Our goal is no death, no scar, and no pain,” adds Jeschke. “With this approach we come closer to no death and no scar.”
Better way to transplant human stem cells (Medical Xpress). Scientists seem more wary about discussing embryonic stem cells than they used to be. This article never uses the term. It names them “hES” cells instead (human embryonic stem cells) used to experiment with “organoids” (small organs developed from hES cells), and later discusses the transfer of “pluripotent” stem cells, without saying if they are iPSCs or adult stem cells. You can tell something is up, though, when they admit in the last sentence, “They also warrant consideration of the ethical issues associated with the development of cerebral organoids for therapeutic purposes.” There are no ethical issues with adult stem cells.
Update 11/13/2018: Serendipitously, Dr Nathaniel Jeanson wrote on this subject for Answers in Genesis on the same day. He provides a brief history of the stem cell debate and the reasons for ethical concerns. He concludes that the pro-life community is on the verge of a major victory, with adult stem cells proving more suitable for therapy than human embryos, without any of the ethical concerns.
The good (adult stem cells and iPSCs), the bad (human embryonic stem cells) and the ugly (prospects for human cloning) require citizens to pay close attention to what is being discussed. These are matters of life, death, and human nature.