Progress in Lung Repair

Inflammation and scarring get a bad rap. They naturally occur during a healthy response to lung injury.

Inflammation is the result of numerous cells flocking to the site of an injury where they begin initiating tissue repair. A scar is a temporary scaffold that aids the replacement of cells and tissue destroyed by an injury.

Disease occurs when inflammation and scarring persist beyond the time needed for healthy repair, leading to tissue destruction or excessive scarring. Researchers at National Jewish Health are investigating strategies to stop the destructive processes and restart the healing process.

Drivers of Repair

Cells known as macrophages (an immune system cell) serve as orchestrators of lung repair. They sense damage in the lung, and engulf infectious organisms, dying cells and other harmful substances. They sound the alarm that calls other cells and activates repair programs.

William Janssen, MD; Kara Mould, MD; and their colleagues have identified a new subset of macrophages that are the key drivers of lung repair. These macrophages use an alternative energy system that allows them to thrive in damaged, oxygen-poor tissue and to secrete molecules that promote repair of injured tissue.

By more precisely identifying and targeting the macrophages that drive lung repair, Dr. Janssen believes he can better understand what goes wrong during pathological inflammation and scarring, and identify more effective targets for lung repair.

In January 2018, Dr. Janssen identified a molecule that reduces the production of scar tissue by promoting the self-destruction of malfunctioning macrophages.