If a patient has Type 1 diabetes, then
their ability to produce insulin is inhibited, usually by a loss of
beta cells in the pancreas. Researchers have been looking at ways to
replace the lost population of cells, but the process is difficult, often requiring the patient's immune system to be suppressed in order to be effective.
Now, researchers at ETH Zurich have made a big breakthrough,
successfully creating functional beta cells using stem cells
extracted from the fatty tissue of a 50 year-old patient.
The researchers started by extracting endogenous stem cells from patient fatty deposits. Then, in a laboratory environment, a complex synthetic network of genes, which the researchers refer to as genetic software, was applied to the cells, recreating the pattern of growth factors involved in the maturation process.
The genetic software works by increasing and decreasing concentrations of three essential growth factors called Ngn3, Pdx1 and MafA. Carefully controlling the concentrations is, according to the researchers, the key to inducing the harvested cells into becoming beta cells. For example, MafA is not present at all at the start of the process, but about four days in, it increases dramatically, with concentrations then remaining high for the rest of development.
The genetic software represents a big step forward, with such processes previously handled via manually adding the right quantities of components throughout growth. Such practice was both difficult to get right, and not suitable for wide spread use.
The beta cells produced by the ETH Zurich researchers were found to be similar to their naturally-occurring counterparts in both appearance and function. They contain dark spots – known as granules – in which the insulin is stored, and the general function of the cells is the same, though they don't secrete quite as much insulin as natural cells.
Perhaps the most significant benefit of the new treatment is that the patient's immune system does not need to be suppressed, as would be the case is foreign tissue were being used. Cells can be harvested from a patient, engineered into beta cells, and inserted back into them, without the risk of rejection associated with foreign material.
Still, while these results are extremely positive, there's a lot more work to be done. So far, the engineered beta cells have only been produced in a petri dish. Now that the genetic software method has been proved effective in that environment, clinical trials can be considered.
The findings of the research were published in the journal Nature Communications.
Source: ETH Zurich