Peroxidasin is essential for endothelial cell survival and growth signaling by sulfilimine crosslink‐dependent matrix assembly

Abstract

Peroxidasin (PXDN) has been reported to crosslink the C-terminal non-collagenous domains of collagen IV (Col IV) by forming covalent sulfilimine bond. Here, we explored the physiological role of PXDN and its mechanism of action in endothelial cell survival and growth. Silencing of PXDN using siRNAs decreased cell proliferation without increase of the number of detached cells and decreased cell viability under serum-starved condition with increased fragmented nuclei and caspase 3/7 activity. Conditioned medium (CM) containing wild-type PXDN restored the proliferation of PXDN-depleted cells, but CM containing mutant PXDN with deletion of either N-terminal extracellular matrix (ECM) motifs or peroxidase domain failed to restore PXDN function. Accordingly, anti-PXDN antibody [raised against IgC2 (3-4) subdomain within ECM motifs] and peroxidase inhibitor phloroglucinol prevented the rescue of the PXDN-depleted cells by PXDN-containing CM. PXDN depletion resulted in loss of sulfilimine crosslinks, and decreased dense fibrillar network assembly of not only Col IV, but also fibronectin and laminin like in Col IV knockdown. Exogenous PXDN-containing CM restored ECM assembly as well as proliferation of PXDN-depleted cells. Accordingly, purified recombinant PXDN protein restored the proliferation and ECM assembly, and prevented cell death of the PXDN-depleted cells. PXDN depletion also showed reduced growth factors-induced phosphorylation of FAK and ERK1/2. In addition, siPXDN-transfected cell-derived matrix failed to provide full ECM-mediated activation of FAK and ERK1/2. These results indicate that both the ECM motifs and peroxidase activity are essential for the cellular | 10229

Uric Acid Reacts with Peroxidasin, Decreases Collagen IV Crosslink, Impairs Human Endothelial Cell Migration and Adhesion

“…HEK293 cells presented β1γ1 subunits, but the laminin α1β1γ1 heterotrimers were identified in HEK293/PXDN overexpressing cells only. These observations corroborate recent findings showing a PXDN dependence on the expression of collagen IV, fibronectin, and laminin in ECM [ 47 ]. Thus, PXDN presence might contribute to laminin production.…”

Phenotypic melanoma heterogeneity is regulated through cell-matrix interaction-dependent changes in tumor microarchitecture

“…In C8161 MITF-OE compared to C8161 EV spheroids, we confirmed a decrease in peroxidasin, an enzyme responsible for fibrillar network assembly of collagen IV, fibronectin and laminin (47,48), and a decrease in serpin H1, another crucial enzyme for collagen maturation (49,50).…”

Peroxidasin protein expression and enzymatic activity in metastatic melanoma cell lines are associated with invasive potential

“…Conformational changes of modified proteins may alter the susceptibility or resistance to proteolytic degradation and oxidants may furthermore impact on DNA and RNA integrity, function, stability and DNA methylation [ [21] , [22] , [23] , [24] ]. Moreover, activity of PXDN was shown to promote angiogenesis via ERK1/2, AKT and FAK pathways [ 25 ] and is required for ECM-mediated signaling via ERK1/2 and FAK, influencing cell growth and survival [ 26 ]. This highlights how PXDN activity has the potential to influence many aspects of tumor biology.…”