Stem cells

By Joseph Milton, FT science intern

Simulations run by a team at the University of Bristol suggest that the melting of the Greenland ice sheet could be prevented by reflecting sunlight from the earth’s surface, a geoengineering technique.

Geoengineering offers radical solutions to climate change, involving large-scale alterations to the environment, directly affecting the climate. Discussion of these potentially risky procedures is increasingly common as many scientists reach the conclusion that CO2 emission reduction targets are not being met, and are unlikely to be. The Royal Society recently invited a panel of scientists to look into the subject and produce a report: Geoengineering the climate: science, governance and uncertainty.

The research at Bristol, led by Peter Irvine and published today in Environmental Research Letters, found that the temperature of the planet could be reduced to pre-industrial levels, saving the ice sheet, by reflecting 4.2 per cent of incident sunlight back into space.

But reflecting such a high percentage of sunlight, while doing nothing to reduce atmospheric CO2 levels, could reduce rainfall and change weather patterns, so the team also investigated reflecting 2.5 per cent of sunlight. They found this reduced the undesired side effects, but still cooled the planet enough to avoid the collapse of the ice sheet.

The Bristol team suggest sunlight could be deflected using geoengineering techniques known as solar radiation management. One option is the use of space reflectors – trillions of tiny reflective particles at the Lagrange point, the point in space at which the Earth and the Sun’s gravitational fields cancel each other out.

Professor Peter Cox at the University of Reading, who worked on the Royal Society report, says it might work: “It would be like just turning the sun down a bit.” But obviously there are technical considerations. As Professor Joanna Haigh of Imperial College, another of the report’s authors, points out: “The costs and the timescales involved would be absolutely enormous.” Neither thinks this technique is feasible in the near future.

Another option suggested by the Bristol team involves the addition of sulphate particles to the atmosphere, where they would reflect solar radiation. Prof. Cox says this is more difficult to rule out than he had imagined before the report was written, but Prof. Haigh is less convinced: “Who knows what the knock-on effects would be?” she says.

Solar radiation management is one of two broad categories of geoengineering techniques. The second is carbon dioxide removal, recently suggested as a possible complement to mitigation actions by Rajendra Pachauri, head of the Intergovernmental Panel on Climate Change.

Removing CO2 from the atmosphere would be a better long-term solution to global warming, as it would tackle not just global temperatures but other problems associated with high levels of greenhouse gases too, such as ocean acidification. But it would be very slow to affect the climate. On the other hand, the effects of reflecting sunlight could be seen within a few years.

Peter Irvine stressed that geoengineering should only be regarded as an emergency response: “It is no substitute for reductions in the emission of CO2,” he said.

Clive Cookson

Another sign today of stem cell research becoming more commercial: An announcement that Stephen Minger, one of the field’s leading academics, will join GE Healthcare next week as head of Research and Development for Cell Technologies.

Minger, an American, has been in charge of stem cell biology at Guy’s Hospital and King’s College London since moving to the UK in 1996.

As well as being one of the top researchers into human embryonic stem cells in Britain – his lab has derived several hESC lines including ones with genetic mutations for cystic fibrosis and Huntington’s disease – Minger has been a fearless public advocate of stem cell science.

The relatively science-friendly legislative and regulatory framework for embryo research that has emerged in the UK owes something to Minger’s communications skills. He is one of the most open and media-friendly scientists I have come across, in any field.

Stephen Minger

Stephen Minger

“Leading GE Healthcare’s Cell Technologies research and development will allow me to bring many years of academic research in the stem cell field to bear in a commercial environment,” he says. “This is an opportunity for me to play a leading role in the realization of the emerging potential of stem cell technology in drug discovery and therapy, and to help grow a strategic business for GE Healthcare.”

GE Healthcare, part of the giant US General Electric group, is one of the world’s largest and most broadly based medical technology companies. It made clear its corporate ambitions in stem cell research at the end of June when it announced an exclusive alliance with Geron, the leading US stem cell company. Minger will, among other duties, lead the GE side of the Geron partnership. He will be based in the UK.

GE’s role in the commercialisation of stem cells will be to provide a comprehensive range of cells and tools for research and development. It does not intend to produce its own treatments.

Incidentally Geron has commented further on last week’s decision by the US Food and Drug Administration to put “on hold” its application to carry out the world’s first clinical trial of a treatment based on embryonic stem cells.  The product would treat spinal cord injury.

The California-based company says the FDA suspension relates to “microscopic cysts” that appeared on some animals during preclinical testing. Reassuringly, the cysts were not cancerous and had no adverse effects on the animals, so it seems likely that the clinical trial will go ahead soon.

“It is appropriate for the FDA to be particularly cautious about the first clinical trial of embryonic stem cells,” Minger says.

Clive Cookson

Stem cell research has had another eventful week, with interesting developments on the regulatory and corporate fronts, as well as in the lab.

On Monday the Obama administration released the final version of the rules under which federal funding can be released through the National Institutes of Health to support embryonic stem cell research.

As expected, lobbying by the US scientific community has paid off. The rules are more permissive than the surprisingly restrictive version that the administration originally proposed in April, following President Obama’s pledge to loosen his predecessor’s harsh limits on NIH funding.

US researchers will be able to work with hundreds of stem cell lines derived from surplus IVF embryos, rather than the 21 approved by the Bush administration. But there is still a lot that NIH will not be allowed to fund, including the creation of new embryos specifically for research – for example through therapeutic cloning. Such work will have to rely on private, charitable or state funding.

A potentially important new company emerged this week: iPierian. It is a combination of two stem cell start-ups, iZumi and Pierian, lubricated with an additional $11.5m in new venture funding.

iPierian will focus on induced pluripotent stem cells – iPSCs – the embryonic-like cells produced by reprogramming adult cells, which have been the focus of much stem cell research over the past couple of years. The company aims to produce “disease-specific” cells from patients with neurodegenerative diseases, which can then be used to develop drugs to treat these diseases.

A powerful positive for iPierian is the reputation of its scientific founders and advisors, who include some of Harvard’s top stem cell scientists such as George Daley, Douglas Melton and Lee Rubin.

Sperm made from embryonic stem cell

Sperm made from embryonic stem cell

The week’s most striking scientific news was released in the UK, where Karim Nayernia and colleagues at Newcastle University announced the creation of human sperm from embryonic stem cells. Although other researchers cast some doubt on whether the sperm were as mature and functional as Nayernia claimed, the work undoubtedly has great potential for the study – and eventually the treatment – of male infertility.

Clive Cookson

Embryonic stem cells get all the publicity in stem cell research, good and bad. Their supporters see them as the future of regenerative medicine, producing all manner of new human tissues to treat degenerative diseases. Opponents – mainly from religious groups – hate the fact that they originate with the destruction of an embryo.

No treatment based on human embryonic stem cells has yet been tested on patients, though the US Food and Drug Administration recently told Geron that it could begin a clinical trial of embryonic stem cells to treat spinal injury. Meanwhile, as the UK national stem cell conference in Oxford heard today, universities are making good progress using adult stem cells, derived from the patients themselves, to repair bone and cartilage.

At Southampton University Richard Oreffo is leading a programme to fill holes or gaps in bones caused by accident or disease with a “living composite” material, made of stem cells extracted from the patient’s bone marrow mixed with a biocompatible scaffold.

Four patients have so far received transplants of living composite, says Prof Oreffo. Early signs are encouraging: the material is integrating well with the patients’ own bone and stimulating natural regrowth.

Meanwhile Alicia El Haj of Keele University is working on a 10-year clinical trial at Oswestry Orthopaedic Hospital, using adult stem cells to repair cartilage damaged in accidents. The patients’ stem cells are multiplied outside the body, before being injected back into injured joints.

Although the Oswestry trial uses stem cells on their own, Prof El Haj is also leading a more futuristic research project in which stem cells are linked to microscopic magnetic nanoparticles. “We can then use a magnet to move the stem cells around the body and control what they do there,” she says.

Magnetic control could be far more effective than simply injecting stem cells into the patient. The nanoparticle system has already produced new tissue growth in laboratory mice and is about to be tested in goats, ahead of clinical trials.

While adult stem cells are more readily available than embryonic stem cells – and pose no ethical problems – they are much less versatile. However Prof El Haj said techniques developed for adult stem cells, such as magnetic control, could be adapted to embryonic stem cells or the recently discovered “induced pluripotent stem cells” (which are made by reprogramming adult cells so that they revert to an embryonic state).

At present stem cell trials use one-off procedures developed by individual research teams. “We need to move away from bespoke therapy into standard procedures that can be used by [doctors] anywhere,” says Prof El Haj.

Although many scientists and patient groups are impatient for stem cell research to deliver clinical benefits more quickly, Prof Oreffo says it is important not to push ahead too fast: “The last thing we want is a case that goes wrong, because that would set the field back tremendously.”

Clive Cookson

Scientists at Sheffield university have taken an important step towards using stem cells to restore hearing to deaf people.

Their research shows for the first time how embryonic stem cells can be converted into the specialist cells we rely on for hearing. These sensory hair cells and auditory neurons, as they are known, cannot be regenerated in adults using existing medical technology; once they are damaged, hearing loss is permanent.

The long-term aim is to treat deafness by transplanting new auditory cells, generated from stem cells, into people who have lost their own.

“We have found the recipe to persuade embryonic stem cells, which can become any cell in the body, to become auditory cells,” says Marcelo Rivolta, who has led the Sheffield project for the past five years. “Our lab studies have shown that these cells behave and function just like their counterparts in our developing ears.”

The research started by studying cells from the developing ears of aborted human foetuses (around 10 weeks old) and then applied the findings to embryonic stem cells (which originate in early embryos just a few days old). The next step will be to graft the specialist auditory cells into deaf strains of laboratory animals.

The research – funded by the charities Royal National Institute for Deaf People and Deafness Research UK – is published online by the journal Stem Cells and will be discussed at next week’s UK National Stem Cell conference in Oxford.

Ralph Holme, director of biomedical research at RNID, says: “Stem cell therapy for hearing loss is still some years away but this research is incredibly promising and opens up exciting possibilities by bringing us closer to restoring hearing in the future.”

A more immediate application will be for research into deafness. “We have now an experimental system to study genes and drugs in a human context,” says Dr Rivolta, who is originally from Argentina.

“In addition to the future potential for restoring hearing with stem cell therapy, the recent research success means that we may now have better ways to test the efficacy and toxicity of new drugs on auditory cells,” adds Vivienne Michael, chief executive of Deafness Research UK.

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Clive Cookson, the FT's science editor, picks out the research that everyone should know about, in fields from astronomy to zoology. He also discusses key policy issues, from R&D funding to science education. He'll cover the weird and wonderful, as well as the serious side of science.