Oldest Root Stem Cells From the Carboniferous

Scientists at Oxford University have discovered the oldest known population of plant root stem cells in a 320 million-year-old fossil.

The cells, which gave rise to the roots of an ancient plant, were found in a fossilised root tip held in the Oxford University Herbaria.

As well as revealing the oldest plant root stem cells identified to date, the research also marks the first time an actively growing fossilised root has been discovered - in effect, an ancient plant frozen in time.

The study is published in the journal Current Biology.

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Stem Cell Treatment Hyped to Claim Human Might be Able to Regenerate Like Salamanders Soon

In what could prove to be a game changer in stem cell therapy, a team led by scientists at the University of New South Wales (UNSW) have discovered a way to reprogram bone and fat cells to become stem cells that can regenerate multiple tissue types. The technique has already proved successful in mice and could be just a few years away from being safely available for regenerating any damaged tissue in humans.

According to the scientists, most of the unproven stem cell therapies today have been shown to be ineffective in forming new tissue. There are also issues related to using embryonic stem cells and stem cell generation.

"Embryonic stem cells cannot be used to treat damaged tissues because of their tumor forming capacity," says study co-author Dr. Vashe Chandrakanthan. "The other problem when generating stem cells is the requirement to use viruses to transform cells into stem cells, which is clinically unacceptable."

Multiple studies over the last year have looked at various ways of using stem cells to repair specific tissues and organs like the heart, eyes, and lungs. What makes the UNSW-led project different is that it turns existing bone and fat cells into induced multipotent stem cells (iMS), thus avoiding both the scientific and ethical issues surrounding stem cell use.

The new technique, which has been successfully demonstrated in mice, takes adult human fat cells and treats them with a compound called 5-Azacytidine (AZA) and platelet-derived growth factor-AB (PDGF-AB) for around two days. Following this the cells are treated with PDGF-AB for an additional three weeks.

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Men Close to Obsolete? Scientists Produce Sperm From Stem Cells

Researchers in China say that they have discovered a way to make rudimentary mouse sperm in a dish, and used them to produce offspring.

If the claim stands up to scrutiny, it could point the way to making human sperm in the lab for fertility treatments. But some scientists are not convinced by the report, which is published today inCell Stem Cell.

“The results are super-exciting and important,” says Jacob Hanna, a stem-cell scientist at the Weizmann Institute of Science in Rehovot, Israel. But Takashi Shinohara, a reproductive biologist at Kyoto University in Japan, is among researchers who have doubts about the work: he notes that scientists have struggled to replicate several previous claims that sperm can be made in a dish.

In 2011, molecular biologists led by Mitinori Saitou at Kyoto University reported that they had managed to recreate the first stages of sperm development in a dish. They coaxed mouse embryonic stem cells to become cells that resembled primordial germ cells (PGCs)—an important stage in the development of both eggs and sperm.

Saitou's team then implanted the artificial PGCs into a mouse: when implanted in testes, they grew to become sperm; in ovaries, they matured into eggs.

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Kidneys Grown From Stem Cells Transplaneted Into Rats, Pigs

Japanese researchers have successfully grown a pair of kidneys in a laboratory which were transplanted into an animal and verified as functioning correctly. This is the first step to growing such organs and transplanting them into humans.

So far, rats and pigs have been tried. The first wave was with rats, but what is more interesting is the effect with a more complex animal like a pig. The success shown here bring the possibility of a human kidney transplant, using laboratory engineered kidneys, a step closer.

The newly grown kidneys were created from stem cells, using rats as the incubators for the growing embryonic tissue. The kidneys are grown complete with a drainage tube and bladder for the collection of urine.

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Scientists Produce Germ-line Cells From Human Skin

Researchers from Cambridge University and Israel’s Weizmann Institute of Science are claiming a stem cell research breakthrough that would allow a baby to be created from the skin cells from two adults, no matter their gender. This potentially allows for infertile couples to have their own children without resorting to sperm or egg donors, and may provide the means for same sex couples to produce their own babies.

Previously only successful in experiments on mice, the new research has been conducted on human cells for the first time. In this study, the researchers paired stem cell lines from embryos with the skin of a range of different adults, with the resultant cells compared to aborted fetuses to determine an identical match.

Techniques devised to create same-sex offspring are not new. Some experiments involve the manipulation of fibroblasts in mice resulting in offspring with the genetic traits of multiple male mice, whilst others have used bone marrow stem cells extracted from males to trigger spermatogonia.

However, in this latest research, stem cells and adult human skin have been combined for the first time to create an entire new germ-cell line (that is, cells that will become embryos). Derived from ten different donor sources, the new germ-cell lines were created from 10 different donor sources – five embryos and five adults.

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Report: Thymus Regenerated in Old Mice

REGENERATIVE medicine—the idea that it is possible to renew old, worn-out tissue and thus keep a body going beyond the point when its organs start to fail—is an attractive idea. To that end, much effort has been put into creating and nurturing so-called pluripotent stem cells. These, when appropriately nudged, can be induced to turn into cells of any other type. They might thus be used for all sorts of repairs. Pluripotent cells, which once had to be extracted from embryos, can now be made routinely from body cells (skin cells, for example). Experiments are therefore going on to see if, when made from the cells of a particular individual, they might be used to repair damage to that person’s organs without (as a transplant from someone else would) attracting the attention of his immune system.

This approach is promising. It would be even better, though, if rather than having stem cells transplanted into it, a degenerate organ could be persuaded to repair itself. Until now, no one has managed to do this. But Clare Blackburn of Edinburgh University, in Britain, and her colleagues have succeeded. As they report in Development, they have treated, in mice, an organ called the thymus, which is a part of the immune system that runs down in old age. Instead of adding stem cells they have stimulated their animals’ thymuses to make more of a protein called FOXN1. This is a transcription factor (a molecular switch that activates genes), and for the thymus it turns out to be an elixir of life.

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Sperm From Stem Cells

Human sperm have been created using embryonic stem cells for the first time in a scientific development which will lead researchers to a better understanding of the causes of infertility.

Researchers led by Professor Karim Nayernia at Newcastle University and the NorthEast England Stem Cell Institute (NESCI) have developed a new technique which has made the creation of human sperm possible in the laboratory.

The work is published today (8th July 2009) in the academic journal Stem Cells and Development.

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In the technique developed at Newcastle, stem cells with XY chromosomes (male) were developed into germline stem cells which were then prompted to complete meiosis - cell division with halving of the chromosome set. These were shown to produce fully mature, sperm called scientifically, In Vitro Derived sperm (IVD sperm).

In contrast, stem cells with XX chromosomes (female) were prompted to form early stage sperm, spermatagonia, but did not progress further. This demonstrates to researchers that the genes on a Y chromosome are essential for meiosis and for sperm maturation.

Can't quite do away with us yet ladies.

Lentivirus Used to Make Stem Cells in Single Step

A Boston University School of Medicine-led research team has discovered a more efficient way to create induced Pluripotent Stem (iPS) cells, derived from mouse fibroblasts, by using a single virus vector instead of multiple viruses in the reprogramming process. The result is a powerful laboratory tool and a significant step toward the application of embryonic stem cell-like cells for clinical purposes such as the regeneration of organs damaged by inherited or degenerative diseases, including emphysema, diabetes, inflammatory bowel disease, and Alzheimer's Disease.

Their research titled "iPS Cell Generation Using a Single Lentiviral Stem Cell Cassette" appears on line in the journal Stem Cells.

Prior research studies have required multiple retroviral vectors for reprogramming -- steps that depended on four different viruses to transfer genes into the cells' DNA – essentially a separate virus for each reprogramming gene (Oct4. Klf4, Sox2 and cMyc). Upon activation these genes convert the cells from their adult, differentiated status to what amounts to an embryonic-like state.

However, the high number of genomic integrations -- 15 to 20 -- that typically occurs when multiple viruses are used for reprogramming, poses a safety risk in humans, as some of these genes (i.e. cMyc) can cause cancer. In addition, the viruses can integrate in cell locations turning on potential oncogenes.

The major milestone the six-member research team, led by Gustavo Mostoslavsky, Boston University Assistant Professor of Medicine in the Gastroenterology Section, achieved was combining the four vectors into a single "stem cell cassette" containing all four genes. The cassette (named STEMCCA) is comprised of a single multicistronic mRNA encoding the four transcription factors using a combination of 2A peptide technology and an internal ribosomal entry site (IRES).

With the STEMCCA vector, the researchers were able to generate iPS cells more efficiently -- 10 times higher than previously reported studies.

"The use of a single lentiviral vector for the derivation of iPS cells will help reduce the variability in efficiency that has been observed between different laboratories, thus enabling more consistent genetic and biochemical characterizations of iPS cells and the reprogramming process," the researchers concluded.

A little more about how the lentivirus was being used for the non biotech types.