Tag Archives: embryonic stem cell

Scientists use embryonic stem cells to create bone, heart muscle in just 5 days

Researchers from Stanford University have quickly and efficiently created pure populations of 12 different cell types – including bone, heart muscle and cartilage – from ancestral embryonic stem cells.

Image credit Pixabay

Image credit Pixabay

Stem cells of these cell types have been created in the past, but the current study marks the first time that pure populations have been created in a matter of days as opposed to weeks or months. In addition, previous techniques typically led to impure mixtures that contained multiple cell types, limiting their practical use.

“Regenerative medicine relies on the ability to turn pluripotent human stem cells into specialized tissue stem cells that can engraft and function in patients,” said Irving Weissman, the director of Stanford’s Institute for Stem Cell Biology and Regenerative Medicine. “It took us years to be able to isolate blood-forming and brain-forming stem cells.”

“Here we used our knowledge of the developmental biology of many other animal models to provide the positive and negative signaling factors to guide the developmental choices of these tissue and organ stem cells,” he added. “Within five to nine days we can generate virtually all the pure cell populations that we need.”

Embryonic stem cells are pluripotent, meaning they have the ability to form into any cell type in the body. This process is guided by various time- and location-specific cues that occur within the embryo, ultimately pushing their development in the direction of a specific cell type. Scientists understand a lot about how this process is guided in animals such as fish, mice, and frogs, but due to the restrictions on human embryo cultivation, they know little about human embryonic development.

In the new study, the team learned that human stem cells move down a developmental path that is composed of a series of choices that present just two possible options. They found that the best way to guide these cells towards a particular fate was to encourage the differentiation into one lineage and at the same time block the other pathway. In other words, saying “yes” to one choice while simultaneously saying “no” to the other.

“We learned during this process that it is equally important to understand how unwanted cell types develop and find a way to block that process while encouraging the developmental path we do want,” said Kyle Loh, co-lead author of the study, which was published July 14 in the journal Cell.

Through careful guidance of the developmental pathway, Loh and the team were able to push stem cell differentiation in the direction that they wanted, leading to the creation of 12 different cell lineages in a quick and effective manner.

“Next, we’d like to show that these different human progenitor cells can regenerate their respective tissues and perhaps even ameliorate disease in animal models,” he said.

Lab-Grown Kidneys Transplanted to Animals

For the first time, Japanese researchers have successfully grown a pair of kidneys in a lab and then transplanted them into animals. The organs functioned just fine, and this gives big hopes for the transplants ultimately moving to humans.

Dr. Takashi Yokoo and one of the test subjects. Image via CBS.

So far, they tried it on rats and pigs; the rats ones worked well right from the start, but it was more of a challenge moving on to a more advanced animal like a pig (pigs are actually similar to us biologically in a number of ways). The positive results that they reported on pigs actually raises hopes for human transplants.

Professor Chris Mason, an independent scientist based at University College London praised the study.

“This is an interesting step forward. The science looks strong and they have good data in animals.”

The artificial kidneys were created from embryonic stem cells, grown in the lab. Dr Takashi Yokoo and colleagues at the Jikei University School of Medicine in Tokyo also set a drainage tube and a bladder for the kidneys, to prevent them from swelling up and accumulating liquids. Urine first passes from the artificial kidney to the artificial bladder and then to the real bladder. Eight weeks later, when they checked their results, everything was still working fine.

However, while extremely promising, human trials are still years away. Mason added:

“This is an interesting step forward. The science looks strong and they have good data in animals. But that’s not to say this will work in humans. We are still years off that. It’s very much mechanistic. It moves us closer to understanding how the plumbing might work. At least with kidneys, we can dialyse patients for a while so there would be time to grow kidneys if that becomes possible.”

Journal Reference: Shinya Yokote et al, Urine excretion strategy for stem cell-generated embryonic kidneys. doi: 10.1073/pnas.1507803112

Adult mice grown from eggs and sperm induced by pluripotent stem cells. (c) Mitinori Saitou and Katsuhiko Hayashi

Scientists grow mice from dish-cultured sperm and egg

Adult mice grown from eggs and sperm induced by pluripotent stem cells. (c) Mitinori Saitou and Katsuhiko Hayashi

Adult mice grown from eggs and sperm induced by pluripotent stem cells. (c) Mitinori Saitou and Katsuhiko Hayashi

Kyoto University researchers have produced normal, healthy mouse pups after inseminating a foster mother with eggs and sperm derived from stem cells, exclusively grown in a petri dish. This remarkable accomplishment came after last year scientists produced mouse pups from stem cell grown sperm. Their research might lead to the development of novel techniques through which infertile couples may conceive.

“This is a significant achievement that I believe will have a sustained and long-lasting impact on the field of reproductive cell biology and genetics,” says Amander Clark, a stem cell biologist at University of California, Los Angeles.

The team of researchers, lead by Mitinori Saitou, first collected both embryonic stem cells (ES) and  induced pluripotent stem cells (iPS). The latter are cell sampled from adult tissue, reprogrammed to act like stem cells. These were cultured  in a cocktail of proteins to produce primordial germ cell-like cells, such that the researchers might obtain oocytes – pre-eggs. The primordial cells were then mixed with fetal ovarian cells, forming reconstituted ovaries that they then grafted onto natural ovaries in living mice.

The scientists found that after four weeks and three days the  primordial germ cell-like cells had developed into oocytes. These were fertilized resulting in embryos which were implanted in surrogate mothers. Three weeks later the first pups were born – healthy and normal.

The Japanese researchers conclude that their “culture system serves as a robust foundation for the investigation of key properties of female germ cells, including the acquisition of totipotency, and for the reconstitution of whole female germ-cell development in vitro.”

The study, published in the journal Science, says that the findings might form the basis for a new technique which might allow for treating infertility.

“This study has provided the critical proof of principle that oocytes can be generated from induced pluripotent stem cells,”

via Wired

Stem cell research: win some, lose some

Stem cell research is still extremely controversial and problematic due to the numerous financial, social, and political pressures often applied on this kind of study. However, as some of the biggest companies working in the field throw the towel, others claim they will not stop their pioneering work, that bring eyesight to the blind and cure broken hearts (literally).

Scientists worldwide were shocked U.S. biotech company Geron Corp announced on Monday they will quit stem cell research, blaming this decision on the lack of money and the complexities of getting regulatory approval. However, teams working on less ambitious adult stem cells project are doing just fine.

“It’s a tale of two ends of the market. I believe the adult stem cell space was always more attractive anyway,” said Navid Malik, a biotechnology analyst at Merchant Securities.

However, science has received a significant blow with the shutdown of this company. Stem cell treatment offers a totally unique and revolutionary way of treating diseases and a number of conditions, which are otherwise incurable and cause the suffering and death of millions. Heart diseases, Parkinsons, kidney failure – these are just a few of the ones that could be helped by this revolutionary treatment.

What happens is embryonic stem cells are harvested from embryos and have the potential to become almost any type of tissue; on the other hand, adult stem cells are less controversial (because they come from adults), but they are also much less flexible, and can only become a number of tissues.

In a more advanced study, researchers were testing an embryonic stem cell treatment aimed at helping patients with spinal cord injuries like the late Superman actor Christopher Reeves – who was paralyzed in an accident.

Making superman walk would have been great for business but was an ambitious target for a serious problem and maybe not the best start scientifically or clinically for stem cell therapies,” said Alison Murdoch, head of the fertility center at Britain’s Newcastle University.

What do you think about embryonic stem cell research ? I’ve asked myself and the ones around me this question numerous times, and I’ve received the most varied and surprising answers.

Via Reuters

Vatican teams up with US biotech firm to shift focus off embryo research

The Vatican have entered an unusual partnership with a relatively small U.S. biotech company (NeoStem) to promote using adult stem cells for treating diseases, instead of focusing on embryonic stem cell research.

The Vatican are perhaps the loudest advocates of not using embryonic stem cells; the Christian teaching holds that the life begins at conception, and as a result, in their view, the loss of embryonic cells equals death.

The partnership will be marked by a conference which will be held in New York, bringing together researchers and cardinals; this initiative is part of the Vatican’s recent $1 million, five-year initiative to promote adult stem cell therapies and research and shift people’s attention from embryonic research. From their point of view, this is a lofty goal, but I’m not sure $1 million in five years will get you very far when dealing with this kind of objective.

Transplant of adult stem cells are already common in treating people with serious illnesses, but many believe that the more flexible and useful embryonic cells are the true key that should be used. Lots of work has and will be put in both camps, but it’s obvious that things are moving in the right direction, and without the usual bureaucracy and obtuse thinking, we would already be a few steps ahead of where we are now.