Donor stem cell–derived retinal epithelial cells whose immune proteins correspond to those of a recipient are tolerated following transplant into monkeys’ eyes, according to a report published today (September 15) in Stem Cell Reports. In an accompanying paper, the team also reports that such immune-matched retinal cells derived from humans prevent immune responses in cultured human lymphocytes.
stem cells
Lab-grown sperm makes healthy offspring
Sperm have been made in the laboratory and used to father healthy baby mice in a pioneering move that could lead to infertility treatments.
The Chinese research took a stem cell, converted it into primitive sperm and fertilised an egg to produce healthy pups.
The study, in the Journal Cell Stem Cell, showed they were all healthy and grew up to have offspring of their own.
Experts said it was a step towards human therapies.
It could ultimately help boys whose fertility is damaged by cancer treatment, infections such as mumps or those with defects that leave them unable to produce sperm.
Breakthrough in human cell transformation could revolutionise regenerative medicine
A breakthrough in the transformation of human cells by an international team led by researchers at the University of Bristol could open the door to a new range of treatments for a variety of medical conditions. Their paper, published today in Nature Genetics, demonstrates the creation of a system that predicts how to create any human cell type from another cell type directly, without the need for experimental trial and error.
Julian Gough, professor of bioinformatics at the University of Bristol, said: ‘The barrier to progress in this field is the very limited types of cells scientists are able to produce. Our system, Mogrify, is a bioinformatics resource that will allow experimental biologists to bypass the need to create stem cells.’
Pluripotent stem cells – or cells that have not yet ‘decided’ what to become – can be used to treat many different medical conditions and diseases. The first human artificialpluripotent stem cells were created by Japanese researcher Shinya Yamanaka in 2007, through a process of educated trial and error that took a long time. In the nine years since, scientists have only been able to discover further conversions for human cells a handful of times.
Scientists are growing mini-kidneys from skin cells
Add this to the list of things you can grow in a petri dish: An honest-to-goodness mini-kidney.
Australian scientists have successfully developed a method that allows mini-kidneys to be grown from stem cells in a lab — an achievement that could help with drug research, as well as one day possibly providing assistance to those in desperate need of a kidney transplant.
Using stem cells derived from human skin cells known as fibroblasts, the team “encouraged” the cells to form a miniature organ, Melissa Little, a professor at the University of Queensland, told Mashable Australia. The research was published in Nature.
Eye Stem Cell Therapy Moves Ahead
Researchers inject retinal support cells derived from human embryonic stem cells into the eyes of four men with macular degeneration, bolstering evidence of the experimental treatment’s safety.
Scientists in Korea have injected human embryonic stem cell (hESC)-derived retinal support cells into the eyes of four men with macular degeneration, according to a study published today (April 30) inStem Cell Reports. Three of the men experienced vision improvements in their treated eyes in the year following the procedure, while the fourth man’s vision remained largely the same. The trial adds to growing evidence that injecting hESC-derived cells is feasible, feeding hopes for their future therapeutic use.
This latest study follows on two papers published inThe Lancet in 2012 and 2014, which similarly demonstrated that hESC-derived cells could be safely injected into the space behind the retina in macular degeneration patients. These studies, sponsored by the Massachusetts-based company Advanced Cell Technology (now Ocata Therapeutics), were the first published accounts describing the application of hESC-based therapies in humans.
Surviving the Ice Age A beginner’s guide to freezing and thawing pluripotent stem cells
Over the past decade, pluripotent stem cells have provided researchers in diverse fields with a new tool to probe developmental biology, define the underlying pathology of diseases, and develop cell-based therapies for genetic disorders. Whatever the source of the stem cells used in a lab—harvested from IVF embryos, garnered from another lab’s cell lines, or reprogrammed from adult cells using chemical factors—they’ll likely all have one destination in common: the freezer.
Whether a lab is managing large collections of individual patient samples or simply saving cell lines to be used for research down the road, freezing cells offers a solution to long-term storage problems and a source for replicating experiments in the future.
But if you’re adding stem cells to your research repertoire, you will need to acquaint yourself with some cryoprotection stumbling blocks. Stem cells, it turns out, generally aren’t as easy to freeze as differentiated cells. You can’t just take your favorite cell-freezing reagent, apply your usual methods, and stick the cells in a box in the freezer.
When scientists first began working with human embryonic stem cells—and putting cell colonies on ice for future use—they found that only around 5 percent of cells in a given sample were alive and pluripotent after a single freeze-thaw cycle. For one thing, stress, including that brought on by cold temperatures, encourages differentiation, says Alexandra Stolzing of the Fraunhofer Institute for Cell Therapy and Immunology in Leipzig, Germany. “If you push them toward a random tissue state, you lose the value of having stem cells in the first place.”
Freezing also seems to activate a programmed cell-death pathway, but adding apoptosis inhibitors to the medium only slightly improves yield in most cases. Researchers are still trying to understand exactly how low temperatures affect pluripotent stem cells and are working to create new protocols and reagents that enable more cells to survive. Slowly, their discoveries are making it easier to pick up the tricks of stem cell cryopreservation.
Not All Stem Cells Created Equal
Compared to induced pluripotent stem cells generated from somatic cells, stem cells created by nuclear transfer appear to be closer to the genetic state of embryonic cells.
In the process of converting a somatic cell to a stem cell, researchers have questioned whether the resulting cells retain characteristics of their prior, non-stem-cell states. Applying two pioneering approaches to create human pluripotent stem cells from somatic cells—by inducing pluripotent stem cells (iPSCs) or using a process called somatic cell nuclear transfer (SCNT)—researchers from Oregon Health & Science University (OHSU) and their colleagues have compared the genomic and epigenomic landscapes of the resulting cell types. They found that the genomes of stem cells created through SCNT more closely match those of embryonic stem cells (ESCs) derived from early human embryos. The team’s comparative analysis was published today (July 2) in Nature.
Shoukhrat Mitalipov, a reproductive biologist and director of the Center for Embryonic Cell and Gene Therapy at OHSU, led the team that developed the SCNT approach just last year. For the present study, Mitalipov said he and his coauthors wanted to better understand the degree to which this new class of pluripotent cells were comparable to iPSCs.
Human skin grown in lab ‘can replace animal testing’
Skin grown in the laboratory can replace animals in drug and cosmetics testing, UK scientists say.
A team led by King’s College London has grown a layer of human skin from stem cells – the master cells of the body.
Stem cells have been turned into skin before, but the researchers say this is more like real skin as it has a permeable barrier.
It offers a cost-effective alternative to testing drugs and cosmetics on animals, they say.
The outermost layer of human skin, known as the epidermis, provides a protective barrier that stops moisture escaping and microbes entering.
An ancient virus may be the reason human stem cells can transform
The embryonic stem cells responsible for producing every other type of cell in the human body gained their power from an ancient virus that copied itself into our DNA millions of years ago, according to new research. National Geographic reports that the discoverycould lead to more effective stem-cell treatments for diabetes, multiple sclerosis, and Parkinson’s disease, among other ailments.