NMMHC IIA inhibition impedes tissue factor expression and venous thrombosis via Akt/GSK3β‐NF‐κB signalling pathways in the endothelium and the modulatory mechanism of D39
Authors: Kou Junping , Zhai Kefeng , Zhang Yuanyuan , Yu Boyang 
Published: June 2021

Non‐muscle myosin heavy chain IIA (NMMHC IIA) has been shown to be involved in thrombus formation and inflammatory microparticle release in endothelial cells. However, the role of NMMHC IIA in regulating the expression of tissue factor (TF) and deep venous thrombosis remains to be elucidated. In the present study, endothelial cells were stimulated with tumour necrosis factor‐α (TNF‐α) to induce TF expression. Pretreatment with the NMMHC II inhibitor blebbistatin suppressed the mRNA and protein expressions as well as the procoagulant activity of TF in a dose‐dependent manner. Blebbistatin enhanced Akt and GSK3β phosphorylation and inhibited NF‐κB p65 nuclear translocation and I B degradation. These observations were similar to the effect of CHIR99021, a GSK3β inhibitor. TF downregulation by blebbistatin was antagonised by the PI3K inhibitor, wortmannin. Furthermore, siRNA knockdown of NMMHC IIA, but not IIB or IIC, inhibited TF expression, activated Akt/GSK3 and suppressed NF‐κB signalling pathways, whereas the overexpression of NMMHC IIA increased TF expression. The binding of NMMHC IIA and TNF receptor 2 mediated signal internalisation in TNF‐α‐stimulated endothelial cells. Importantly, blebbistatin decreased endothelium NMMHC IIA and TF expression, deactivated GSK3β by inducing its phosphorylation, suppressed p65 nuclear translocation, and inhibited thrombus formation in a mouse deep venous thrombosis model. Moreover, D39 inhibited tissue factor expression and procoagulant activities in HUVECs and decreased thrombus weight in inferior venacava‐ligated mice dose‐dependently. Serial affinity chromatography and molecular docking analysis suggested that D39 bound to NMMHC IIA. In HEK293T cells, D39 inhibited tissue factor expression evoked by NMMHC IIA overexpression. This effect was blocked by NMMHC IIA knockdown in HUVECs. D39 inhibited dissociation of NMMHC IIA from TNFR2, which subsequently modulated the Akt/GSK3β–NF‐κB signalling pathways. Our findings provide solid evidence that inhibition of NMMHC II, most likely NMMHC IIA, impedes TF expression and venous thrombosis via Akt/GSK3β‐NF‐κB signalling pathways in the endothelium both in vitro and in vivo. NMMHC IIA might be a potential novel target for the treatment of thrombotic disorders. In addition, we identified a new natural product that targeted NMMHC IIA, as a potential treatment for thrombotic disorders and other vasculopathies.

Support or Funding Information

The present research was supported by the National Natural Science Foundation of China (Grant No. 81274131 and 81601034), 2011’ Program for Excellent Scientific and Technological Innovation Team of Jiangsu Higher Education, a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.