20 July 2011
Inactive cells modified to generate and transmit electrical current
by Kate Melville
By genetically modifying normally "unexcitable" cells, Duke University bioengineers have turned them into cells capable of generating and passing electrical current; a breakthrough which could have broad implications in treating diseases of the nervous system or the heart.
The transformation was achieved by introducing genes that result in the formation of ion channels on the surface of the cells. Ion channels allow electrically charged molecules to exit or enter the cell thus enabling the transfer of electric current from one cell to its neighbor.
The researchers hypothesized that a few key ion channels are sufficient to enable cell excitation. They determined that three particular channels could do the job, including those carrying potassium ions, sodium ions, and a gap junction channel, a highly specialized structure that enables cell-to-cell electrical communication.
"By introducing only three specific ion channels, we were able to give normally electrically inactive cells the ability to become electrically excitable," said researcher Rob Kirkton. "We also demonstrated proof-of-concept experiments in which these modified cells were able restore large electrical gaps within and between rat heart cells."
The results of the Duke experiments, appearing in the journal Nature Communications, open the door to a wide range of novel studies. Genetically engineered excitable cells could be important in treating heart attacks, in which damaged portions of heart muscle become electrically disconnected and are unable to contract in synchrony with neighboring healthy cells.
The Duke scientists say that their engineered excitable cells can be continuously and easily grown in the lab, are genetically and functionally identical to each other, and also have the capacity for further modifications to change their electrical or structural behavior. "These cells can be used in the laboratory as a platform for investigating the roles that specific ion channels have in tissue-level bioelectricity as well as testing the effectiveness of new drugs or therapies on bioelectrical activity," Kirkton said.
Source: Duke University