Abstract
Background:
Ginsenoside Rb1 (Rb1) exerts pharmacological effects in attenuating the progression of atherosclerosis. However, whether the anti-atherosclerotic effects of Rb1 involve suppressing neutrophil extracellular traps (NETs)-induced endothelial activation and whether N6-methyadenosine (m6A) RNA modification is mechanistically implicated in this process remain unknown.
Methods:
High fat diet (HFD)-fed Apoe -/- mice were subjected to histological, immunohistological and molecular biological analyses. Moreover, NETs-induced endothelial activation and m6A RNA methylation were assessed in human aortic endothelial cells (HAECs).
Results:
Rb1 mitigated atherosclerotic lesions and endothelial activation in vivo. Rb1 diminished adhesion of neutrophils and monocytes to NETs-stimulated HAECs, offset NETs-upregulated endothelial expression of ICAM1, VCAM1, SELE and SELP, and counteracted NETs-induced endothelial barrier impairment in vitro. NETs exposure significantly decreased the level of m6A RNA methylation and increased the expression of demethylase fat mass and obesity-associated protein (FTO) in HAECs, whereas Rb1 treatment enhanced m6A RNA methylation and reduced FTO expression in the NETs-stimulated HAECs. Overexpression of FTO abrogated the protective effects of Rb1 against NETs-induced endothelial activation in HAECs. Furthermore, Fto overexpression in endothelial cells partially abolished Rb1-confered attenuation of atherosclerotic pathologies and the aortic expression of Vcam1 in HFD-fed Apoe -/- mice.
Conclusion:
The work here demonstrates that Rb1 mitigates atherosclerosis in part by suppressing NETs-induced endothelial activation. Mechanistically, the pharmacological effects of Rb1 in attenuating NETs-induced endothelial activation are in part mediated by modulating FTO-mediated m6A RNA demethylation in endothelial cells.