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This study investigated the effect of resveratrol on Toll-like receptor 4- (TLR4-) mediated matrix metalloproteinase 3 (MMP3) and MMP9 expression in oxidized low-density lipoprotein- (ox-LDL-) activated platelets and the potential molecule mechanism. Human platelets were used in the present study. The results showed that resveratrol suppressed TLR4, MMP3, and MMP9 expression in ox-LDL-activated platelets. The TLR4 inhibitor CLI-095 also inhibited MMP3 and MMP9 expression and secretion in ox-LDL- and lipopolysaccharide- (LPS-) activated platelets. The combination of resveratrol and CLI-095 synergistically suppressed MMP3 and MMP9 expression in ox-LDL- and LPS-activated platelets. These findings suggest that the resveratrol-induced inhibition of MMP3 and MMP9 expression is linked to the suppression of TLR4 activation. Resveratrol also suppressed spleen tyrosine kinase (Syk) phosphorylation and nucleotide-binding domain leucine-rich repeat containing protein 3 (NLRP3) expression and IL-1 β secretion in ox-LDL- and LPS-treated platelets. The coimmunoprecipitation results showed that resveratrol inhibited the binding of Syk and NLRP3. Finally, resveratrol reduced vascular senescence cells and the expression of TLR4, MMP3, and MMP9 and prevented alterations of vascular structure in 52-week-old mice. Our findings demonstrated that resveratrol decreased inflammatory protein expression and improved vascular structure in aged mice. Resveratrol inhibited the expression of TLR4 and secretion of MMP3, MMP9, and IL-1 β . The mechanism of action of resveratrol appears to be associated with the inhibition of TLR4/Syk/NLRP3 activation in ox-LDL-activated platelets., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Yun Xue et al.)

Resveratrol has many beneficial biological actions, including cardiovascular protection and antithrombotic effects. Whether resveratrol inhibits oxidized low-density lipoprotein (ox-LDL)-induced Toll-like receptor 4 (TLR4) expression in activated platelets remains unclear. The present study investigated the effects of resveratrol on the TLR4-mediated inflammatory response in ox-LDL-activated platelets. The results showed that resveratrol suppressed TLR4 expression in ox-LDL- and lipopolysaccharide (LPS)-activated platelets. Similar effects were found in puromycin-pretreated platelets. This suggests that TLR4 expression might be related to protein synthesis in ox-LDL- and LPS-activated platelets. Further analysis confirmed that resveratrol attenuated the ox-LDL-induced phosphorylation of nuclear factor κB (NF-κB) and signal transducer and activator of transcription 3 (STAT3). A mechanistic analysis indicated that the inhibitory effect of resveratrol on TLR4 expression was associated with the suppression of Akt phosphorylation. The combination of resveratrol and the PI3K inhibitor LY294002 had a synergistic effect on the inhibition of Akt phosphorylation and TLR4 expression. Moreover, resveratrol recovered sirtuin 1 expression and adenosine monophosphate-activated protein kinase phosphorylation, which was reduced by ox-LDL treatment. Furthermore, the platelet function analysis showed that resveratrol (100 μM) reduced platelet aggregation and adhesion and CD40 ligand/platelet factor 4 secretion in ox-LDL-treated platelets. Altogether, the present findings show that resveratrol inhibits the TLR4-mediated inflammatory response in ox-LDL-activated platelets, which may contribute to the treatment of thrombosis and atherosclerosis., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Endothelial cells are sensitive to changes in both blood components and mechanical stimuli. Endothelial cells may undergo phenotypic changes, such as changes in adhesion protein expression, under different shear stress conditions. Such changes may impact platelet and monocyte adhesion to endothelial cells. This phenomenon is linked to chronic vascular inflammation and the development of atherosclerosis. In the present study, we investigated the effects of ginkgolide B on platelet and monocyte adhesion to human umbilical vein endothelial cells (HUVECs) under different conditions of laminar shear stress., Methods: Platelet and monocyte adhesion to endothelial cells was determined by the Bioflux 1000. HUVECs were incubated with ginkgolide B or aspirin for 12 h, and then TNFα was added for 2 h to induce the inflammatory response under conditions of 1 and 9 dyn/cm 2 laminar shear stress. The protein expression was analyzed by Western blot., Results: The number of platelets that adhered was greater under conditions of 1 dyn/cm 2 than under conditions of 9 dyn/cm 2 of laminar shear stress (74.8 ± 19.2 and 59.5 ± 15.1, respectively). Ginkgolide B reduced the tumor necrosis factor α (TNFα)-induced increase in platelet and monocyte adhesion to HUVECs at 1 and 9 dyn/cm 2 of laminar shear stress. In TNFα-treated HUVECs, the number of monocytes that adhered was greater under conditions of 1 dyn/cm 2 of laminar shear stress compared with 9 dyn/cm 2 (29.1 ± 4.9 and 22.7 ± 3.7, respectively). Ginkgolide B inhibited the TNFα-induced expression of vascular cell adhesion molecule-1(VCAM-1), VE-cadherin, and Cx43 in HUVECs at 1 and 9 dyn/cm 2 . The expression of these proteins was not different between 1 and 9 dyn/cm 2 ., Conclusions: Ginkgolide B suppressed platelet and monocyte adhesion under different conditions of laminar shear stress. Moreover, ginkgolide B reduced VCAM-1, VE-cadherin and Cx43 expression in TNFα-treated HUVECs under laminar shear stress. This suggested that ginkgolide B might shed light on the treatment of inflammation in atherosclerosis.

Introduction: Atherosclerosis is a chronic vascular inflammatory disease. Platelets play a critic role in the initiation of vascular inflammation in atherosclerosis. In the present study, we investigated the effects of ginkgolide B on the inhibition of platelet release and the potential mechanisms., Methods: Experiments were performed in freshly human platelets. Platelet aggregation and ATP release were measured with a Lumi-aggregometer. Thrombin (0.5 U/ml) was used to induce platelet activation. Protein expression and phosphorylation was examined by Western blotting., Results: The results showed that ginkgolide B significantly suppressed ATP release by 50.8% in thrombin-activated platelets. Ginkgolide B completely abolished the expression of platelet factor 4 (PF4) and CD40 Ligand (CD40L). Moreover, ginkgolide B fully attenuated the phosphorylation of Syk and p38MAPK. Similarly, R788 (a syk inhibitor) and SB203580 (a p38 MAPK inhibitor) inhibited the expression PF4 and CD40L, respectively. Furthermore, the combination of low concentrations of ginkgolide B and R788 or SB203580 has synergistic inhibition on the expression of PF4 and CD40L. Ginkgolide B partially reduced calcium efflux by 52.7% in thrombin-stimulated platelets., Conclusion: Ginkgolide B potently inhibited the expression of PF4 and CD40L in thrombin-activated platelets. Ginkgolide B partially decreased ATP release and Ca(2+) efflux. The mechanism might be associated with the inhibition of Syk and p38 MAPK phosphorylation. These results demonstrated that ginkgolide B might be a promising drug on inhibiting platelet function and reducing inflammation in atherosclerosis., (Copyright © 2014 Elsevier Ltd. All rights reserved.)