Researchers led by ETH Professor Martin Fussenegger at the Department of Biosystems Science and Engineering (D-BSSE) in Basel have produced artificial beta cells using a straightforward engineering approach. These pancreatic cells can do everything that natural ones do: they measure the glucose concentration in the blood and produce enough insulin to effectively lower the blood sugar level. The ETH researchers presented their development in the latest edition of the journal Science.

Previous approaches were based on stem cells, which the scientists allowed to mature into beta cells either by adding growth factors or by incorporating complex genetic networks.

For their new approach, the ETH researchers used a cell line based on human kidney cells, HEK cells. The researchers used the natural glucose transport proteins and potassium channels in the membrane of the HEK cells. They enhanced these with a voltage-dependent calcium channel and a gene for the production of insulin and GLP-1, a hormone involved in the regulation of the blood sugar level.

Voltage switch causes insulin production

In the artificial beta cells, the HEK cells’ natural glucose transport protein carries glucose from the bloodstream into the cell’s interior. When the blood sugar level exceeds a certain threshold, the potassium channels close. This flips the voltage distribution at the membrane, causing the calcium channels to open. As calcium flows in, it triggers the HEK cells’ built-in signalling cascade, leading to the production and secretion of insulin or GLP-1.