For years, scientists have believed that only nerve cells and heart cells relied on electrical impulses to communicate, while epithelial cells lining the skin, organs and body cavities were thought to be passive barriers, primarily absorbing and secreting substances. However, researchers at the University of Massachusetts Amherst have questioned this assumption, demonstrating that epithelial cells do communicate through slow electrical signals.

The research, led by Steve Granick, the Robert K. Barrett Professor in the Department of Polymer Science and Engineering, and postdoctoral researcher Sun-Min Yu, was recently published in the Proceedings of the National Academy of Sciences. Their findings could pave the way for advances in wearable bioelectric sensors, wound healing and other biomedical applications.

"Epithelial cells do things that people never thought to look for," Granik said. "When injured, they 'scream' to their neighbors, slowly, continuously, and surprisingly far apart. It's like a nerve impulse, but 1,000 times slower." Driven by curiosity, his team combined polymer science with biology to reveal this hidden cellular signaling.

Granick and Yu used an epithelial cell-coated chip with 60 precisely placed electrodes that detect tiny electrical changes. Image source: University of Massachusetts Amherst

Granik and Yu used epithelial cells to coat a chip with 60 electrodes precisely arranged for eavesdropping. Yu, a cell culture expert, grew a layer of human epithelial cells on the chip to detect tiny electrical changes.

They used precise lasers to create "tingle" patterns in individual cells and watched as the signals spread outward. "We track how cells coordinate their responses," Yu explains. “It’s a slow-motion, exciting conversation.”

Unlike nerve cells' rapid bursts of neurotransmitters, epithelial cells rely on ion flow (especially calcium ion flow), which produces signals that are much slower than those in nerve cells but of similar voltage. These signals can persist for long periods of time: Granick and Yu observed cells "talking" for more than five hours at distances nearly 40 times their own length.

Although Granick and Yu showed that calcium ions are necessary for epithelial cells to talk, they have not yet tested other factors that might contribute to the conversation. Although the direct applications of their new findings remain to be seen, the implications are huge.

Compiled from /ScitechDaily