'Remixed' skin cells could lead to new diabetes treatments

"End of injections in sight for diabetics after new discovery," says The Daily Telegraph. If you think you've read a similar headline before, you may be right – replacing insulin injections for type 1 diabetes has been a goal for many years.

Type 1 diabetes happens when the body's immune system mistakenly attacks and destroys insulin-producing beta cells in the pancreas. Without insulin, people cannot control the levels of sugar in the blood.

High blood sugar levels (hyperglycaemia) can damage the blood vessels and nerves, while low blood sugar levels (hypoglycaemia) can cause unconsciousness. Most people with type 1 diabetes need to inject insulin regularly.

In this research, scientists from the University of California report they have used a new process to modify human skin cells into working pancreas cells. They say these cells produced insulin in the laboratory, and seemed to protect mice from diabetes when transplanted into their kidneys.

The hope is that by transplanting new beta cells formed from the person's own skin cells, the pancreas will be able to make insulin again.

The advantage of being able to use skin cells is that cells could be taken from a person's own body and retransplanted after adaptation, meaning they would be less likely to be rejected by the immune system.

This early-stage research is exciting, but much more work is needed before we'll know whether this could become a treatment to replace insulin injections.  

Where did the story come from?

The study was carried out by researchers from the University of California and was funded by the University of California, San Francisco Diabetes and Endocrinology Research Center, the US National Institutes for Health, and other charitable trusts and fellowships.

It was published in the peer-reviewed journal Nature Communications on an open access basis, so you can read the study for free online.

The Daily Mail asked in its headline if this is "the end of insulin jabs", while The Daily Telegraph stated the research heralds the "end of injections ... for diabetics". Both headlines overstate the findings.

This is an experimental treatment that has been shown to work in some mice with chemically induced diabetes. We do not know whether it will be safe or effective in humans. The Independent ran a more measured, cautious account of the research.  

What kind of research was this?

This was laboratory research using modified mice and human skin cells. It is at a very early stage, and not at the point where we can draw conclusions about possible treatments for humans.  

What did the research involve?

The researchers used human skin cells taken from foreskins, and tested a variety of procedures to transform them into cells similar to those found in the pancreas, which produce insulin.

Numerous processes were required to convert the cells, including reprogramming the cells genetically, using growth factors and chemical compounds, so they changed from skin cells to cells similar to early-development gut cells.

The scientists then cultured the cells to grow more of them and used more chemical compounds to promote their growth into pancreatic cells.

The resulting cells were tested in the laboratory to see if they could produce insulin when stimulated with glucose. After this, the cells were transplanted into the kidneys of laboratory mice to see whether they could produce insulin.

The cells were then tested to see whether this was at sufficient levels to stop the mice becoming diabetic after they received treatment to prevent them producing insulin naturally.

Finally, the mice had the kidney containing the cells removed to see what happened to their insulin levels.  

What were the basic results?

The scientists say they were able to produce a plentiful supply of working pancreatic cells that made insulin in the laboratory.

The cells also stopped laboratory mice getting diabetes after they received treatment to prevent them making insulin naturally.

Once the mice had the kidney containing the modified cells removed, they quickly became diabetic. Mice injected with cells that had not been treated to become pancreatic-type cells were not protected against diabetes.  

How did the researchers interpret the results?

The researchers say that, "Our studies represent one of the few examples of human cell types generated through cellular reprogramming that could protect against or even cure an existing disease."

However, they went on to say their cell cultures do not represent all the cells usually found in the insulin-producing structures of the human pancreas, and more research is needed to create a diabetes treatment.  

Conclusion

Scientists have been working towards an end to insulin injections for diabetes for decades now, and none of the promised treatments have yet achieved that goal.

While it's exciting that researchers are making progress with understanding how cells work and can be transformed from one function to another, it's right to be cautious.

This piece of work is one of many research projects looking at different ways to grow functional cells to treat different diseases. The results are exciting, but need to be replicated. There will then need to be new work and further studies to see whether the treatment is safe and effective in humans.

There are many concerns about the use of manipulated cells in the human body – for example, the possibility they could grow abnormally and form tumours. The treatment may not work in humans, even though it seems to work in mice.

Headlines that suggest an end to insulin injections is in sight can unfairly raise people's hopes, leaving them disappointed if the research does not translate into treatment.