A novel role of MMP2 in regulating platelet NOX2 activation

• Published in: Free radical biology & medicine Vol. 152; pp. 355 - 362
• Main Authors: Nocella, Cristina, Cammisotto, Vittoria, Bartimoccia, Simona, Castellani, Valentina, Loffredo, Lorenzo, Pastori, Daniele, Pignatelli, Pasquale, Sanguigni, Valerio, Violi, Francesco, Carnevale, Roberto
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 20.05.2020
• Subjects: Humans; Hydrogen Peroxide; Matrix Metalloproteinase 2 - genetics; Matrix metalloproteinase-2; NADPH Oxidase 2 - genetics; NADPH Oxidases - genetics; NOX2; Oxidative stress; Platelet Activation; Platelets; Reactive Oxygen Species; ROS; Oxidative stress; Platelets; ROS; Matrix metalloproteinase-2; NOX2
• ISSN: 0891-5849; 1873-4596; 1873-4596
• DOI: 10.1016/j.freeradbiomed.2020.03.033

NOX2 has a key role for cellular production of reactive oxidant species (ROS) and although the mechanism of its activation is well known, little is known about its regulation. Metallo-proteinases (MMPs) regulate numerous protein activities both in physiological and pathological conditions but their interplay with NOX2 and ROS formation is still unclear. We performed experimental studies in human platelets and polymorphonuclear leukocytes (PMNs) to investigate the interplay of MMP2 with NOX2 activity. In collagen-stimulated platelets and in PMA-stimulated PMNs from healthy subjects, an immediate burst of ROS was detected at 10 min to then decline at 20 min. Coincidentally, sNOX2-dp, a split-off product of NOX2, increased and peaked at 10 min. ROS production was persistent whereas sNOX2dp is not released in cells treated with MMP2 inhibitor compared to other MMPs inhibitors. Western blot analysis showed the highest MMP2 expression on the cell membrane 10 min after stimulation. Moreover, the co-immunoprecipitation assay confirms the interaction between MMP2 and NOX2 that formed an active immuno-complex. Treating cells with NOX2ds-tat, an inhibitor of NADPH oxidase, significantly reduced ROS formation, sNOX2-dp, MMP2 expression and MMP2-NOX2-complex, which were all restored if cells were added with H2O2. The study provides the first evidence that MMP2 has a key role in blunting platelet NOX2 activity and eventually ROS formation. [Display omitted] •NOX2 has a key role in cellular ROS production but its regulation is still unknown.•Upon NOX2 activation, the sNOX2-dp, a split-off product, is released.•MMPs regulate many protein activities in physiological and pathological conditions.•The immuno-complex MMP2/NOX2 regulates sNOX2dp shedding and ROS production.•MMP2 could represent a novel tool to down-regulate NOX2 activation.