ADAM10 and Src‐signalling contribute to the inflammation‐induced formation of VE‐cadherin fragments in endothelial cells
Authors: Ghoreishi Yalda Gole 
Published: April 2020

It has been shown that the release of Vascular Endothelial‐cadherin fragments (sVE‐cadherin) is closely associated with a loss of endothelial barrier function in an acute inflammation. In this context, it has been suggested that sVE‐cadherin could be a suitable marker for early detection of systemic inflammation and sepsis. However, the detailed mechanisms underlying sVE‐cadherin formation in endothelial cells remain largely unclear. Based on previous findings that suggested a critical role for the activation of the sheddase ADAM10 (a disintegrin and metalloproteinase domain‐containing protein 10), we hypothesize that ADAM10 activation might be dependent on intracellular signaling following pro‐inflammatory stimuli.Human dermal microvascular endothelial cells (HDMECs) were incubated with pro‐inflammatory cytokine Tumor necrosis factor α (TNFα), bacterial Lipopolysaccharide (LPS) from E. coli or a combination of both to mimic acute inflammation. As revealed by ELISA‐based measurements, this resulted in increased levels of sVE‐cadherin in cell culture supernatants compared to the baseline and to untreated controls. Co‐incubation of endothelial cells with the ADAM10‐inhibitor, GI254023X, together with LPS, TNFα or both significantly attenuated inflammation‐induced increase of sVE‐cadherin levels in endothelial cell culture supernatants. Measurements of Transepithelial Electrical Resistance (TER) showed a significant loss of endothelial barrier function after application of TNFα, LPS or both compared to untreated controls. Incubation of endothelial cells with the ADAM10‐inhibitor, GI254023X, together with LPS, TNFα or both significantly blocked inflammation‐induced loss of TER. In line with this inflammation‐induced intercellular gap formation, loss of VE‐cadherin at endothelial cell borders and stress fiber formation in the actin cytoskeleton were attenuated by treatment with the ADAM10‐inhibitor. As has been described previously application of TNFα, LPS or both resulted in augmented phosphorylation of tyrosinkinase src. Importantly, using cell viability assays inflammation‐induced loss of endothelial barrier function was not caused by increased cell death under the conditions used here. The selective Src inhibitor, PP2 attenuated inflammation‐induced loss of endothelial barrier function in TER measurements. Moreover, application of PP2 blocked sVE‐cadherin release, indicating a crosstalk between inflammation‐induced activation of src and ADAM10 activation.In summary, our present data confirm previous findings demonstrating that the inhibition of ADAM10 attenuates sVE‐cadherin formation after the cells were exposed to inflammatory stimuli. Furthermore, inflammation‐induced activation of src contributes to sVE‐cadherin release which suggests that ADAM10 may be regulated by src‐dependent activation in inflammation.Support or Funding InformationYalda Ghoreishi, Sven Flemming, Nicolas SchlegelDepartment of General, Visceral, Transplant, Vascular and Pediatric Surgery University Hospital Wuerzburg, Oberduerrbacherstrasse 6, 97080 Wuerzburg, Germany