Using hepatocyte growth factor (HGF), researchers at Johns Hopkins were able to regrow alveoli and restore lung structure in mice with established emphysema, according to research published in the open-access journal PLOS Genetics.
For the study, researchers used four groups of adult mice: two groups with genetically induced emphysema, one set receiving HGF, the other receiving a placebo; and two groups of healthy mice, divided in half to receive either HGF or a placebo.
“We found that the mice with emphysema, when given the HGF, developed a 17 percent improvement in the size of their air sacs compared to placebo-treated mice, consistent with improved lung structure and function,” said Enid Neptune, M.D., associate professor of pulmonary and critical care medicine at the Johns Hopkins University School of Medicine. “The HGF also was protective, preventing destruction of the alveoli by reducing the oxidative stress that contributes to lung injury. In essence, the HGF was able to block a major enemy of the functioning alveoli.”
The mice with emphysema treated with a placebo did not show any improvement. The healthy mice receiving HGF showed no difference in alveolar size.
Investigators also removed the HGF receptor, known as MET, from young mice whose lungs were still forming. Without MET, the air sacs did not form correctly, blood vessels serving the alveoli were reduced, and there was an increase in both oxidative stress and inflammation. The team concluded that developing alveoli require both HGF and MET signaling in order to form normally.
Researchers believe the experiments may lead to successful treatments to regrow the air sacs in people who suffer from respiratory diseases or in premature infants whose lungs aren’t fully developed.