Epac1 deficiency inhibits basic fibroblast growth factor-mediated vascular smooth muscle cell migration

Inhibition effect of copper-bearing metals on arterial neointimal hyperplasia via the AKT/Nrf2/ARE pathway in vitro and in vivo

In-stent restenosis can be caused by the activation, proliferation and migration of vascular smooth muscle cells (VSMCs), which affects long-term efficacy of interventional therapy. Copper (Cu) has been proved to accelerate the endothelialization and reduce thrombosis formation, but little is known about its inhibition effect on the excessive proliferation of VSMCs. In this study, 316L-Cu stainless steel and L605-Cu cobalt-based alloy with varying Cu content were fabricated and their effects on surface property, blood compatibility and VSMCs were studied in vitro and in vivo. CCK-8 assay and EdU assay indicated that the Cu-bearing metals had obvious inhibitory effect on proliferation of VSMCs. Blood clotting and hemolysis tests showed that the Cu-bearing metals had good blood compatibility. The inhibition effect of the Cu-bearing metals on migration of cells was detected by Transwell assay. Further studies showed that Cu-bearing metals significantly decreased the mRNA expressions of bFGF, PDGF-B, HGF, Nrf2, GCLC, GCLM, NQO1 and HO1. The phosphorylation of AKT and Nrf2 protein expressions in VSMCs were significantly decreased by Cu-bearing metals. Furthermore, it was also found that SC79 and TBHQ treatments could recover the protein expressions of phospho-AKT and Nrf2, and their downstream proteins as well. Moreover, 316L-Cu stent proved its inhibitory action on the proliferation of VSMCs in vivo. In sum, the results demonstrated that the Cu-bearing metals possessed apparent inhibitory effect on proliferation and migration of VSMCs via regulating the AKT/Nrf2/ARE pathway, showing the Cu-bearing metals as promising stent materials for long-term efficacy of implantation.

Regulation of bFGF-induced effects on rat aortic smooth muscle cells by β3-adrenergic receptors

Background

Basic fibroblast growth factor (bFGF)-mediated vascular smooth muscle cell (VSMC) proliferation and migration play an important role in vascular injury-induced neointima formation and subsequent vascular restenosis, a major event that hinders the long-term success of angioplasty. The function of β₃-adrenergic receptors (β₃-ARs) in vascular injury-induced neointima formation has not yet been defined.

Objectives

Our current study explored the possible role of β₃-ARs in vascular injury-induced neointima formation by testing its effects on bFGF-induced VSMC migration and proliferation.

Methods

β₃-AR expression in rat carotid arteries was examined at 14 days following a balloon catheter-induced injury. The effects of β₃-AR activation on bFGF-induced rat aortic smooth muscle cell proliferation, migration, and signaling transduction (including extracellular-signal-regulated kinase/mitogen activated protein kinase, ERK/MAPK and Protein kinase B, AKT) were tested.

Results

We found that vascular injury induced upregulation of β₃-ARs in neointima. Pretreatment of VSMCs with a selective β₃-AR agonist, CL316,243 significantly potentiated bFGF-induced cell migration and proliferation, and ERK and AKT phosphorylation. Our results also revealed that suppressing phosphorylation of ERK and AKT blocked bFGF-induced cell migration and that inhibiting AKT phosphorylation reduced bFGF-mediated cell proliferation.

Conclusion

Our results suggest that activation of β₃-ARs potentiates bFGF-mediated effects on VSMCs by enhancing bFGF-mediated ERK and AKT phosphorylation and that β₃-ARs may play a role in vascular injury-induced neointima formation.

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β₃-adrenergic receptor (β₃-AR) expression was upregulated in the newly formed intima following rat carotid artery injury.

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Activation of β₃-ARs potentiated bFGF-induced VSMC migration and proliferation and phosphorylation of ERK and/or AKT.

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Inhibition of ERK or AKT pathways decreased bFGF-induced cell migration.

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Inhibition of AKT pathway decreased bFGF-induced cell proliferation.

miR‑125a‑5p and miR‑7 inhibits the proliferation, migration and invasion of vascular smooth muscle cell by targeting EGFR

The ectopic proliferation, migration and invasion of vascular smooth muscle cells (VSMCs) contributes to the progression of various human vascular diseases. Accumulating evidence has demonstrated that microRNAs (miRs) exert vital functions in the proliferation and invasion of VSMCs. The current study aimed to elucidate the functions of miR-125a-5p and miR-7 in VSMCs and investigate the associated molecular mechanisms. The results of EdU and reverse transcription-quantitative PCR assays revealed that platelet-derived growth factor (PDGF)-BB enhanced the proliferation of VSMCs and significantly reduced the expression of miR-125a-5p and miR-7. miR-125a-5p or miR-7 overexpression significantly ameliorated PDGF-BB-induced proliferation, migration and invasion of VSMCs. Furthermore, the results demonstrated that epidermal growth factor receptor (EGFR) may be a target mRNA of miR-125a-5p and miR-7 in VSMCs. The results of western blot analysis indicated that co-transfection of miR-125a-5p mimics or miR-7 mimics distinctly decreased the protein expression of EGFR in EGFR-overexpressed VSMCs. Moreover, rescue experiments indicated that EGFR overexpression alleviated the suppressive impact of the miR-125a-5p and miR-7 s on the growth, migration and invasion of VSMCs. In conclusion, the current study identified that miR-125a-5p and miR-7 repressed the growth, migration and invasion of PDGF-BB-stimulated VSMCs by, at least partially, targeting EGFR. The current study verified that miR-125a-5p and miR-7 may be used as feasible therapeutic targets for cardiovascular diseases.

EPAC in Vascular Smooth Muscle Cells

Vascular smooth muscle cells (VSMCs) are major components of blood vessels. They regulate physiological functions, such as vascular tone and blood flow. Under pathological conditions, VSMCs undergo a remodeling process known as phenotypic switching. During this process, VSMCs lose their contractility and acquire a synthetic phenotype, where they over-proliferate and migrate from the tunica media to the tunica interna, contributing to the occlusion of blood vessels. Since their discovery as effector proteins of cyclic adenosine 3′,5′-monophosphate (cAMP), exchange proteins activated by cAMP (EPACs) have been shown to play vital roles in a plethora of pathways in different cell systems. While extensive research to identify the role of EPAC in the vasculature has been conducted, much remains to be explored to resolve the reported discordance in EPAC’s effects. In this paper, we review the role of EPAC in VSMCs, namely its regulation of the vascular tone and phenotypic switching, with the likely involvement of reactive oxygen species (ROS) in the interplay between EPAC and its targets/effectors.

Anti-enolase１antibodies from a patient with systemic lupus erythematosus accompanied by pulmonary arterial hypertension promote migration of pulmonary artery smooth muscle cells

OBJECTIVE

Pulmonary arterial hypertension (PAH) is an intractable complication in connective tissue diseases, but the pathological mechanisms responsible for progression remain obscure. This study aims to test whether patient IgG possesses biological activity promoting the migration of pulmonary artery smooth muscle cells (PASMCs).

METHODS

Cell migration was estimated by lamellipodia formation and by utilizing a Boyden chamber method. The specificity of autoantibodies was established by western blotting, ELISA, and immunocytochemistry. The target antigen was investigated by mass spectrometry.

RESULTS

IgG obtained from a patient with systemic lupus erythematosus (SLE) accompanied by PAH was found to promote lamellipodia formation and migration of PASMCs. The IgG bound to a ∼50 kDa protein expressed on the cell membrane, and in the cytoplasm and nucleus. This molecule was identified as enolase 1. Removal of enolase 1-binding antibodies from the IgG fraction, or treatment of the cells with an enolase inhibitor, significantly suppressed the migration of PASMCs.

CONCLUSION

Patients with SLE may possess autoantibodies to enolase 1 which stimulate the migration of PASMCs and are likely to play a role in the progression of PAH.