The Study On The Protection Of The ATRQβ-001 Vaccine Against Atherosclerosis In Apolipoprotein E-null Mice

Backgroud and Objective:The renin-angiotensin systemin (RAS) play a pivotal role in the pathogenesis of advanced atherosclerotic plaques. Angiotensin Ⅱ (AngⅡ) type 1 receptor (AT1R) blockers have been proved to reduce atherosclerosis. Previously, we have invented ATRQβ-001 vaccine which showed a desirable blocking effect for AT1R. The purpose of this study was to investigate whether ATRQβ-001 vaccine would prevent atherosclerosis in apolipoprotein E-null (ApoE-/-) mice.Methods:Five-week-old, male ApoE-/- mice were randomly divideded into the flowing four groups, namely, the ATRQβ-001 group (ATRQβ-001), the VLP group (VLP), the valsartan group (Valsartan,8mg/kg/d), respectively. ATR-001-specific antibody titers were measured on days 7,14,21,49,77,105 and 160. For the assessment of plaque lesion in aortic sinus and the whole aorta, the frozen histological sections of the aortic sinus or en face surface of the whole aorta was processed. To assess the apoptosis in the atherosclerotic lesions, the apoptotic cells were detected by TUNEL using an in situ cell death detection kit. PRA and AngⅡ concentration was quantified by radioimmunoassay. To evaluate the he protective effect of the anti-ATR against atherosclerosis in vitro, we examined the anti apoptosis of the anti-ATR in endothelial cells. In additions, we also investigated the regulatory function of the anti-ATR on the macrophage metabolism.Results:ATRQβ-001 vaccine significantly reduced the lesion area and promoted the stability of atherosclerotic plaque. Meanwhile, macrophage infiltration as well as the expressions of adhesion molecules (VCAM-1) and monocyte chemoattractant protein-1 (MCP-1) was obviously decreased in the ATRQβ-001 vaccine group. Additionally, the vaccine markedly reduced the apoptosis in the lesions of the ApoE-/- mice. In vitro, the anti-ATR-001 antibody inhibited endothelial apoptosis induced by Angll. Additionally, the anti-ATR-001 antibody attenuated the intracellular cholesteryl ester synthesis in macrophage while still promoting the cholesterol efflux. Furthermore, ATRQP-001 vaccine exhibited a dramatical attenuation in the expressions of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and AT1R in the aortic. More importantly, compared with the valsartan group, no obvious feedback of plasma renin-angiotensin system (RAS) was elicited in the vaccine group. The ATRQβ-001 vaccine was found to be basically safe, although further assessments are needed to confirm this statement.Conclusions:The results demonstrated that ATRQβ-001 vaccine reduced the progression of atherosclerosis in ApoE-/- mice. According our results, its mechanism may be through inhibiting the formation foam cells, reducing the inflammation and apoptosis caused by AngⅡ and regulating the macrophage polarization in the plaque area during the course of atherosclerosis. In additions, compared to chemical drugs, non feedback activation of loop RAS is also a unique advantage of the vaccine, although the specific reasons need to be further studied.