Caveolae-mediated endocytosis of extracellular QSOX1b modulates the migration of fibroblasts

Exp Cell Res. 2024 Jan 2:113906. doi: 10.1016/j.yexcr.2023.113906. Online ahead of print.ABSTRACTQuiescin/sulfhydryl oxidase (QSOX1) is a secreted flavoprotein that modulates cellular proliferation, migration and adhesion, roles attributed to its ability to organize the extracellular matrix. We previously showed that exogenously added QSOX1b induces smooth muscle cells migration in a process that depends on its enzymatic activity and that is mediated by hydrogen peroxide derived from Nox1, a catalytic subunit of NAD(P)H oxidases. Here, we report that exogenous QSOX1b also stimulates the migration of L929 fibroblasts and that this effect is regulated by its endocytosis. The use of endocytosis inhibitors and caveolin 1-knockdown demonstrated that this endocytic pathway is caveola-mediated. QSOX1b colocalized with Nox1 in intracellular vesicles, as detected by confocal fluorescence, suggesting that extracellular QSOX1b is endocytosed with the transmembrane Nox1. These results reveal that endosomal QSOX1b is a novel intracellular redox regulator of cell migration.PMID:38176465 | DOI:10.1016/j.yexcr.2023.113906

Source: Experimental Cell Research - January 4, 2024 Category: Cytology Authors: Pierina A Martinez Silvio M Zanata Lia S Nakao Source Type: research