Synthetic E-selectin prevents postoperative vascular restenosis by inhibiting nuclear factor κB in rats

Apolipoprotein J Attenuates Vascular Restenosis by Promoting Autophagy and Inhibiting the Proliferation and Migration of Vascular Smooth Muscle Cells

This research investigated the mechanism of CLU in vascular restenosis by regulating vascular smooth muscle cell (VSMC) proliferation and migration. Firstly, rat models of balloon injury (BI) were established, followed by the assessment of the injury to the common carotid artery. The effect of CLU on the intimal hyperplasia of BI rats was measured after the intervention in CLU, in addition to the evaluation of proliferation, migration, and autophagy of VSMCs. Moreover, the interaction between ATG and LC3 was analyzed, followed by validation of the role of autophagy in CLU's regulation on the proliferation and migration of VSMCs. It was found that CLU was highly expressed in BI rats. Altogether, our findings indicated that CLU was highly expressed in vascular restenosis, and CLU over-expression promoted the binding between ATG3 and LC3, thus facilitating VSMC autophagy and eventually attenuating intimal hyperplasia and vascular restenosis.

Metformin represses the pathophysiology of AAA by suppressing the activation of PI3K/AKT/mTOR/autophagy pathway in ApoE-/- mice

Background

The protective effect of metformin (MET) on abdominal aortic aneurysm (AAA) has been reported. However, the related mechanism is still poor understood. In this study, we deeply investigated the role of metformin in AAA pathophysiology.

Methods

Angiotensin II (Ang-II) was used to construct the AAA model in ApoE^−/− mice. The related mechanism was explored using Western blot and quantitative real time PCR (qRT-PCR). We also observed the morphological changes in the abdominal aorta and the influence of metformin on biological behaviors of rat abdominal aortic VSMCs.

Results

The PI3K/AKT/mTOR pathway was activated in aneurysmal wall tissues of AAA patients and rat model. Treatment with metformin inhibited the breakage and preserved the elastin structure of the aorta, the loss of collagen, and the apoptosis of aortic cells. In addition, metformin significantly suppressed the activation of the PI3K/AKT/mToR pathway and decreased the mRNA and protein levels of LC3B and Beclin1, which were induced by Ang-II. Moreover, PI3K inhibitors enhanced the effect of metformin while PI3K agonists largely reversed this effect. Interestingly, the cell proliferation, apoptosis, migration and autophagy of vascular smooth muscle cells (VSMCs) induced by Ang-II were also decreased following metformin treatment. PI3K inhibitors and agonists strengthened and weakened the effects of metformin in VSMCs, respectively.

Conclusions

Metformin represses the pathophysiology of AAA by inhibiting the activation of PI3K/AKT/mTOR/autophagy pathway. This repression may be useful as a new therapeutic strategy for AAA.

Ultrasmall superparamagnetic nanoparticles targeting E-selectin: synthesis and effects in mice in vitro and in vivo

Purpose: We developed a contrast agent for targeting E-selectin expression. We detected the agent using magnetic resonance imaging (MRI) in vivo in nude mice that had undergone nasopharyngeal carcinoma (NPC) metastasis.

Methods: Sialyl Lewis X (sLe^X) was conjugated with ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles. Hydrodynamic size, polydispersity index, and ζ-potential of USPIO–polyethylene glycol (PEG) nanoparticles and USPIO-PEG-sLe^X nanoparticles were measured. Component changes in nanoparticles of USPIO, USPIO-PEG, and USPIO-PEG-sLe^X were analyzed by thermogravimetric analysis and Fourier-transform infrared spectroscopy. A model of NPC metastasis to inguinal lymph nodes in nude mice was used to investigate characteristics of the USPIO-PEG-sLe^X nanoparticles in vivo. We investigated the ability of the T2* value, change in T2* value (ΔT2* value), and enhancement rate (ER) to assess accumulation of USPIO-PEG-sLe^X nanoparticles quantitatively in mice of a metastasis group and control group. Four MRI scans were undertaken for each mouse. The first scan (t0) was done before administration of USPIO-PEG-sLe^X nanoparticles (0.1 mL) via the tail vein. The other scans were carried out at 0 (t1), 1 (t2), and 2 hours (t3) postinjection. The mean optical density was used to reflect E-selectin expression.

Results: sLe^X was labeled onto USPIO successfully. In vivo, there were significant interactions between the groups and time for T2* values after administration of USPIO-PEG-sLe^X nanoparticles. Six parameters (T2* at t2, ΔT2* at t1, ΔT2* at t2, ER at t1, ER at t2, and ER at t3) were correlated with the mean optical density.

Conclusion: USPIO-PEG-sLe^X nanoparticles can be used to assess E-selectin expression quantitatively. Use of such molecular probes could enable detection of early metastasis of NPC, more accurate staging, and treatment monitoring.