Although it may sound straight out of a horror movie, scientists from Ecole Polytechnique Federale de Lausanne have discovered that chronic inflammation can cause regenerating cells to grow into new types of cells. In their study, they found that eye cells turned into skin. The aberrant process is called metaplasia, which is a disorder linked to prolonged inflammation, and the findings could help in the development of better treatments for the strange disorder.
Metaplasia stems from the fact that chronic inflammation activates the immune system for long periods of time, which is why it underlies various disorders associated with chronic inflammation, such as cancer and abnormal wound healing. However, until now, scientists were unaware that chronic inflammation could lead to cells changing type.
Most tissues have a supply of stem cells to help in the process of healing and recovery after injuries, and to understand how these cells act under conditions of chronic inflammation, the researchers examined stem cells in mice corneas. They stimulated chronic inflammation using unique research methods and analyzed the data by lighting up specific cells in the corneas with fluorescent stains.
The results showed that in the cornea, the stem cell environment changed - it became more rigid - and the scientists believe that this is due to the presence of immune cells as well as an increase in the substance that aids cells when they stick together to form organs and other internal structures. This stiff environment caused the stem cells to turn on the wrong differentiation programs, which are biological programs that guide cells to their intended purpose, and they turned into skin cells instead of corneal cells, causing the mice to go blind.
"Our study demonstrates an important mechanism by which chronic inflammation induces abnormal stem cell behavior," Freddy Radtke, senior researcher of the study, said in a press release. "This is relevant to a variety of diseases associated with chronic inflammation, including cancer, and could yield new therapeutic targets."
The findings were published in the Dec. 21 issue of Nature Cell Biology.
