The proliferation and migration of vascular smooth muscle cells are significant in the development and progression of atherosclerosis and plaque rupture. Metformin is a widely used antidiabetic drug, which has been reported to inhibit cell growth and migration. The antiproliferative and antimigratory effects of metformin have been attributed to 5′ adenosine monophosphate-activated protein kinase (AMPK) activation. The purpose of the present study was to investigate the effects of metformin on primary human aortic muscle cells (HASMCs) in vitro and to clarify the underlying mechanism. We investigated the effectiveness of metformin in inhibiting the proliferation and migration of HASMCs in vitro using RNA extraction and reverse transcription-quantitative polymerase chain reaction (RT-qPCR), cell number counting, cell viability assay, cell cycle assay and cell migration assay. Through transfection with small interfering (si)RNA targeting p53 and interferon-inducible protein 16 (IFI16), the roles of p53 and IFI16 in these processes were evaluated. The present study demonstrated that p53, IFI16 and AMPK were upregulated in senescent primary HASMCs, which exhibited a decrease in proliferation and migration. In addition, metformin was able to activate p53, IFI16 and AMPK, in order to inhibit proliferation and migration of HASMCs. Furthermore, siRNA-mediated knockdown of p53 and IFI16 attenuated AMPK activation and reversed the suppressive effects of metformin. Notably, in response to metformin, the activation of AMPK was not observed in p53- and IFI16-silenced HASMCs. These results indicated that metformin-induced activation of AMPK suppresses the proliferation and migration of HASMCs by upregulating p53 and IFI16. These findings suggested that metformin may have potential use in the treatment of atherosclerosis.

Background: Metformin has been shown to inhibit the proliferation and migration of vascular wall cells. However, the mechanism through which metformin acts on atherosclerosis (AS) via the long non-coding RNA taurine up-regulated gene 1 (lncRNA TUG1) is still unknown. Thus, this research investigated the effect of metformin and lncRNA TUG1 on AS. Methods: First, qRT-PCR was used to detect the expression of lncRNA TUG1 in patients with coronary heart disease (CHD). Then, the correlation between metformin and TUG1 expression in vitro and their effects on proliferation, migration, and autophagy in vascular wall cells were examined. Furthermore, in vivo experiments were performed to verify the anti-AS effect of metformin and TUG1 to provide a new strategy for the prevention and treatment of AS. Results: qRT-PCR results suggested that lncRNA TUG1 expression was robustly upregulated in patients with CHD. In vitro experiments indicated that after metformin administration, the expression of lncRNA TUG1 decreased in a time-dependent manner. Metformin and TUG1 knockdown via small interfering RNA both inhibited proliferation and migration while promoted autophagy via the AMPK/mTOR pathway in vascular wall cells. In vivo experiments with a rat AS model further demonstrated that metformin and sh-TUG1 could inhibit the progression of AS. Conclusion: Taken together, our data demonstrate that metformin might function to prevent AS by activating the AMPK/mTOR pathway via lncRNA TUG1.

Background Controversy still exists that whether clopidogrel should add proton pump inhibitors (PPIs) in patients with coronary heart disease after percutaneous coronary intervention (PCI). The aim of this study was to evaluate the efficacy and safety of clopidogrel added proton pump inhibitors (PPIs) vs. clopidogrel for the treatment of patients with coronary heart disease after percutaneous coronary intervention (PCI). Methods and results We systematically searched PubMed, EMBASE, Web of Science, the Chinese Biomedical Medical Literature database, and the Cochrane Library for all clinical trials that were published on this topic through October 2018. We specifically selected the clinical trials that evaluated the efficacy and safety of clopidogrel added proton pump inhibitors vs. clopidogrel in the treatment of patients with coronary heart disease after PCI. RevMan 5.0 software was used for quantitative data analyses. 15 randomized controlled trials including 50,366 patients were included. The meta-analysis results showed that compared with the clopidogrel added PPI group, the non-PPI group had significantly less risk of MACE[RR = 0.82,95%CI:0.77–0.88], myocardial infarction recurrence[RR = 0.72,95%CI:0.57–0.90], stent thrombosis[RR = 0.71,95%CI:0.56–0.92], Target vessel revascularization (TVR)[RR = 0.77,95%CI:0.63–0.93] and stroke [RR = 0.72,95%CI:0.67–0.76]. The risks of all cause death [RR = 1.14,95%CI:0.85–1.51], cardiovascular death [RR = 1.14, 95% CI: 0.85–1.52], bleedings events [RR = 1.60,95%CI:0.53–4.81] were similar in the two groups. Conclusions The patients in the non-PPI group were observed to be associated with less risk of MACE, myocardial infarction recurrence, stent thrombosis, target vessel revascularization (TVR) and stroke. And the two groups had similar all cause death, cardiovascular death, bleedings events.

Apoptosis of vascular endothelial cells (VECs) is highly important in the occurrence and development of atherosclerosis (AS). HomeboxC6 (HOXC6) is expressed in higher levels in multiple malignant tissues, and it influences the malignant biological behavior of the cancer cells. However, the effects of HOXC6 on AS and the apoptosis of VECs have not been fully elucidated. In this study, we demonstrated that HOXC6 expression was increased in aortic wall of AS rats and peripheral blood monocytes of patients with coronary heart disease. Furthermore, it was uncovered that BAX expression was upregulated, while BCL-2 expression was downregulated in the aortic wall of AS rats. The apoptosis of human VECs (HVECs) cultured normally or treated with oxidized low-density lipoprotein in vitro was decreased after transfection with HOXC6-siRNA. Moreover, the results of Western blot analysis unveiled that the expressions of proapoptotic proteins, such as BAX, caspase-3, cleaved-caspase-3, and caspase-9 were reduced, while the expression of antiapoptotic protein, BCL-2, was elevated. Meanwhile, mRNA and protein expressions of phospholipase C beta (PLCβ) were decreased, the phosphorylation levels of protein kinase C zeta (PKCζ) and nuclear transcription factor-κB-p65 (NF-κBp65) and the membrane translocation of PKCζ were reduced as well. Besides, the expression of interleukin-18 (IL-18) protein was downregulated. However, after overexpression of HOXC6, the opposite trends of the abovementioned indices were observed. Furthermore, the inhibition of apoptosis induced by HOXC6-siRNA was reversed by lysophosphatidylcholine, an activator of PKCζ. Taken together, our results indicated that HOXC6 can promote the apoptosis of HVECs and may be involved in the occurrence and development of AS, which may be partially associated with the activation of PLCβ/PKCζ/NF-κBp65/IL-18 signaling pathway.