Scientists have created artificial
cells that act as sugar sensors and insulin producers, an advance that may
spell an end to painful needle jabs to monitor blood glucose levels, making the
everyday life of diabetics easier.
Researchers have used the simplest
approach yet to produce artificial beta cells from human kidney cells. The
therapy involves a capsule of genetically engineered cells implanted under the
skin that automatically release insulin as required. Diabetic mice that were
treated with the cells were found to have normal blood sugar levels for several
weeks.
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 the new
approach, researchers at ETH Zurich (Swiss Federal Institute of Technology in
Zurich) 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. In the
artificial beta cells, the HEK cells' natural glucose transport protein carries
glucose from the bloodstream in to 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.
“They worked better and for longer than
any solution achieved anywhere in the world so far,“ said Professor Martin
Fussenegger from ETH Zurich. “When implanted into diabetic mice, the modified
HEK cells worked reliably for three weeks, producing sufficient quantities of
the messengers that regulate blood sugar level,“ said Fussenegger.
In developing the artificial cells,
experts had the help of a computer model which allows predictions to be made of
cell behaviour, which can be verified experimentally .
Source: The
Times of India-13th-December-2016
