Proteomics Reveal SERPINF1 and PCOLCE Dysregulation During Cardiac Outflow Tract Development in Adamts5−/− Mice

Approximately 2.5% of adults have aortic valve disease (AVD), which is often accompanied by ascending aortic artery (AscAo) malformations (aortopathies). Despite the prevalence, there are no pharmacologic treatments for AVD. To identify novel factors involved in AVD, liquid chromatography–tandem mass spectrometry (LC-MS/MS)-based label-free proteomics was performed on lysates of cardiac outflow tracts (OFTs), the developmental precursors of the AV and AscAo. There were 232 proteins differentially expressed in the OFT of mice deficient in the extracellular matrix (ECM) proteoglycanase A Disintegrin and Metalloprotease with ThromboSpondin repeats 5 (ADAMTS5; n = 7), which develop fully penetrant AVD and aortopathies with excess aggregating proteoglycans, Versican (VCAN) and Aggrecan (ACAN). Gene ontology (GO) analysis indicated that peptidase regulator and endopeptidase inhibitor activities were enriched in the Adamts5−/− OFT. The serine peptidase inhibitor clade F, family member 1 (SERPINF1), and procollagen C-endopeptidase enhancer (PCOLCE) were among the differentially expressed proteins validated by immunohistochemistry and immunoblots. These data indicate that loss of ADAMTS5 amplifies the dysregulation of additional proteolytic factors during OFT development. Elucidating the ADAMTS5 network that influences proteoglycan levels during development may lead to effective therapeutic targets for AVD, in which massive accumulation of VCAN and ACAN is a hallmark of the pathology.