Acute lung injury remains the third major cause of mortality worldwide, and it is assumed that excessive inflammatory responses could be involved.
The precise role of dipeptidyl peptidases (DPPs; a family of enzymes that cleave off dipeptides from the amino terminus of peptides) in the pathophysiology of acute lung injury is poorly understood. Taken broadly, the DPP family consists of DPPIV, fibroblast activation protein alpha (FAP), prolyl oligopeptidase (PREP), DPP8 and DPP9. DPPIV inhibitors are used in the treatment of diabetes type 2, but evidence for other roles of DPPIV is also emerging. Despite a presumed role of individual peptidases in lung disease, knowledge on DPPs in acute lung injury remains limited. Previously, we have shown that DPPIV inhibitors protect against lung ischemia-reperfusion induced injury. Apart from that, we discovered that DPP9 has a role in macrophage activation, which is an important component of acute lung injury.
The current project aims to explore the hypothesis that DPPIV, DPP9 and related peptidases play a role in the pathophysiology of acute lung injury. We will study the expression of DPPs in both an infectious and a non-infectious mouse model of acute lung injury. Subsequently, we will determine the effect of DPPIV inhibition on the outcome, and will assess whether DPPs have a role in lung macrophages. We will compare the animal findings with measurements in human tissue to study the translational potential of our results.