Abstract
The inflammatory responses of vascular endothelial cells (VECs) are critical in the development of many cardio-cerebrovascular diseases. Let-7e is an important regulator of endothelial function and inflammation. However, the effects and mechanisms of let-7e on VECs inflammation have not been studied until recently. Thus, we investigated these issues and found that in addition to proliferation, apoptosis and cell adhesion, let-7e was also implicated in the regulation of inflammatory responses through a complex network, including IκBβ and lncRNA lnc-MKI67IP-3. Let-7e promoted NF-κB activation and translocation to the nucleus by inhibiting its target gene (IκBβ) expression and subsequently increased the expression of inflammatory and adhesion molecules. Meanwhile, lnc-MKI67IP-3 acted as a sponge or competing endogenous RNA (ceRNA) for let-7e, suppressing its pro-inflammatory effects, and let-7e decreased lnc-MKI67IP-3 expression, thereby forming a positive feedback loop to aggravate inflammation. Moreover, let-7e, lnc-MKI67IP-3 and IκBβ were also abnormal in oxLDL-treated VECs and atherosclerotic plaques. The present study revealed let-7e as a pro-inflammatory mediator and a novel regulatory mechanism for the NF-κB pathway through ceRNA crosstalk, comprising let-7e and its target IκBβ and the ceRNA lnc-MKI67IP-3. Thus, this molecule might play important roles in the inflammatory responses of VECs and development of atherosclerosis.