PURPOSE: Vascular adhesion protein (VAP)-1, a multifunctional molecule with adhesive and enzymatic properties, is expressed at the surface of vascular endothelial cells of mammals. It also exists as a soluble form (sVAP-1), which is implicated in oxidative stress via its enzymatic activity. This study explores a link between increased level of sVAP-1 and oxidative stress in proliferative diabetic retinopathy (PDR) with a focus on mechanistic components to form sVAP-1 by shedding from retinal endothelial cells. METHODS: Protein levels of sVAP-1 and N epsilon-(hexanoyl)lysine (HEL), an oxidative stress marker, in the vitreous samples from patients with PDR or non-PDR were measured by ELISA. The mechanism of VAP-1 shedding under diabetic condition, exposure to high glucose and/or inflammatory cytokines, was explored using cultured retinal capillary endothelial cells. RESULTS: Protein level of sVAP-1 was increased and correlated with HEL in the vitreous fluid of patients with PDR. Retinal capillary endothelial cells released sVAP-1 when stimulated with high glucose or inflammatory cytokines, such as TNF-α and IL-1β in vitro. Furthermore, matrix metalloproteinase-2 and -9, type IV collagenases, were the key molecules to mediate the protein cleavage of VAP-1 from retinal capillary endothelial cells. CONCLUSIONS: Our data for the first time provide evidence on the link between sVAP-1 and type IV collagenases in the pathogenesis of PDR.
PURPOSE:Vascular adhesion protein (VAP)-1, a multifunctional molecule with adhesive and enzymatic properties, is expressed at the surface of vascular endothelial cells of mammals. It also exists as a soluble form (sVAP-1), which is implicated in oxidative stress via its enzymatic activity. This study explores a link between increased level of sVAP-1 and oxidative stress in proliferative diabetic retinopathy (PDR) with a focus on mechanistic components to form sVAP-1 by shedding from retinal endothelial cells. METHODS: Protein levels of sVAP-1 and N epsilon-(hexanoyl)lysine (HEL), an oxidative stress marker, in the vitreous samples from patients with PDR or non-PDR were measured by ELISA. The mechanism of VAP-1 shedding under diabetic condition, exposure to high glucose and/or inflammatory cytokines, was explored using cultured retinal capillary endothelial cells. RESULTS: Protein level of sVAP-1 was increased and correlated with HEL in the vitreous fluid of patients with PDR. Retinal capillary endothelial cells released sVAP-1 when stimulated with high glucose or inflammatory cytokines, such as TNF-α and IL-1β in vitro. Furthermore, matrix metalloproteinase-2 and -9, type IV collagenases, were the key molecules to mediate the protein cleavage of VAP-1 from retinal capillary endothelial cells. CONCLUSIONS: Our data for the first time provide evidence on the link between sVAP-1 and type IV collagenases in the pathogenesis of PDR.
Authors: Jaime Retamal; Jens Sörensen; Mark Lubberink; Fernando Suarez-Sipmann; João Batista Borges; Ricardo Feinstein; Sirpa Jalkanen; Gunnar Antoni; Göran Hedenstierna; Anne Roivainen; Anders Larsson; Irina Velikyan Journal: Am J Nucl Med Mol Imaging Date: 2016-01-28
Authors: Ahmed M Abu El-Asrar; Kaiser Alam; Marta Garcia-Ramirez; Ajmal Ahmad; Mohammad Mairaj Siddiquei; Ghulam Mohammad; Ahmed Mousa; Gert De Hertogh; Ghislain Opdenakker; Rafael Simó Journal: Mol Vis Date: 2017-12-05 Impact factor: 2.367