Pathologic Proteolytic Processing of N-Cadherin as a Marker of Human Fibrotic Disease

Abstract

Prior research has implicated the involvement of cell adhesion molecule N-cadherin in tissue fibrosis and remodeling. We hypothesize that anomalies in N-cadherin protein processing are involved in pathological fibrosis. Diseased tissues associated with fibrosis of the heart, lung, and liver were probed for the precursor form of N-cadherin, pro-N-cadherin (PNC), by immunohistochemistry and compared to healthy tissues. Myofibroblast cell lines were analyzed for cell surface pro-N-cadherin by flow cytometry and immunofluorescent microscopy. Soluble PNC products were immunoprecipitated from patient plasmas and an enzyme-linked immunoassay was developed for quantification. All fibrotic tissues examined show aberrant PNC localization. Cell surface PNC is expressed in myofibroblast cell lines isolated from cardiomyopathy and idiopathic pulmonary fibrosis but not on myofibroblasts isolated from healthy tissues. PNC is elevated in the plasma of patients with cardiomyopathy (p ≤ 0.0001), idiopathic pulmonary fibrosis (p ≤ 0.05), and nonalcoholic fatty liver disease with cirrhosis (p ≤ 0.05). Finally, we have humanized a murine antibody and demonstrate that it significantly inhibits migration of PNC expressing myofibroblasts. Collectively, the aberrant localization of PNC is observed in all fibrotic tissues examined in our study and our data suggest a role for cell surface PNC in the pathogenesis of fibrosis.

Identification of a novel variant in N-cadherin associated with dilated cardiomyopathy

“…The adhesive capacity of cadherins relies on the removal of the prodomain because cleavage of the precursor peptide is required for the maturation of N-cadherin. The endogenous cleavage site mutation may not affect the N-cadherin targeting the plasma membrane but may disturb the interaction between N-cadherins to form homodimers ( 33 , 34 ). Previous studies have shown that endogenous protease digestion depends on the recognition site (Arg-X 1 -Lys-Arg-X 2 -Trp, i.e., R-X 1 -K-R-X 2 -W polypeptide) ( 35 ).…”

Endothelial-to-mesenchymal transition: a precursor to pulmonary arterial remodelling in patients with idiopathic pulmonary fibrosis

“…Previously, upregulated N-cadherin expression in alveolar type II cells has been observed in IPF patients and is considered a potential prognostic indicator based on N-cadherin and Ki-67 expression correlation with histological disease activity (26). Recently, Ferrell et al also demonstrated that retention of the N-cadherin prodomain at the cell surface is a potential biomarker of pathological myofibroblasts and is linked with tissues of the heart, lung and liver fibrosis (27).…”

Alpinetin Suppresses Effects of TGF-β1 on Stimulating the Production and Organization of Fibrotic Markers in Human Primary Dermal Fibroblasts

“…Furthermore, it has been demonstrated that the N-cadherin prodomain at the cell surface is a potential biomarker of pathological myofibroblasts and fibrosis in many tissues [ 24 ], and that TGF-β derived from colon cancer cells could induce N-cadherin expression, which consequently promoted invasion of myofibroblasts [ 23 ]. In association with cell motility and invasion, N-cadherin molecules were complexed with β-actin and the α-SMA cytoskeleton, and the findings suggested that N-cadherin might stimulate invasion by forming adherens junctions linked to the cytoskeleton [ 45 ].…”

“…Human fibroblasts have been proven to express N-cadherin [ 22 ], and TGF-β can induce the expression of N-cadherin, which is involved in myofibroblast invasion and migration [ 23 ]. Specifically, pathologic proteolytic processing of N-cadherin has been identified as a marker of human fibrotic diseases [ 24 ]. Since TGF-β has diverse fibrotic effects, this growth factor has become a potential therapeutic target for skin fibrotic diseases.…”