Researchers exploring new regenerative medicines
Researchers are exploring ways to regrow damaged tissues using specialized blood cells that play a role in diseases such as fibrosis.
These fibrocytes cluster around wounds once they start healing, changing shape to facilitate that process. According to a recent UW-Madison study published in the journal Science Advances, the cells play a role in “both adaptive and maladaptive wound healing,” meaning the healing process can sometimes go overboard.
In the study, Associate Professor of Surgery Nathan Welham and his colleagues showed these fibrocytes could be used to regrow vocal cords or other tissues that become damaged or removed.
"This study shows their potential,'' Welham says. "It's a paradigm shift. Fibrocytes are not just bad guys that cause terrible fibrosis.”
In one of the tests outlined in the study, researchers simulated an injury and then tracked how nearby cells responded. They found fibrocytes send out a certain protein signal that can draw other cells important for wound healing.
Still, Welham said this process is not entirely understood.
“While fibrocytes are certainly associated with wound healing and fibrosis, it's unclear whether they act directly, signal other cells at key phases of the healing process, or do both,” he said.
Part of the study focused on how the fibrocytes transform over the course of weeks, altering their internal metabolisms. The researchers then used the mature fibrocytes to build several multilayered tissues, creating potential models for injury-healing products.
They first created a base layer of the cells using a premade scaffold. They added a second layer of epithelial cells -- which line the internal and external surfaces of the body -- and found the fibrocyte layer supported growth of these cells. They also tried to make the second layer out of blood-derived fibrocytes, but were less successful.
"We could get them part of the way there, but not all the way,'' Welham reports. "They would never stratify and mature; we couldn't grow the epithelium beyond a single layer of cells. It may not be possible, or perhaps we didn't take the right approach."
This latest study was supported by several grants from the National Institutes of Health.