Chronic administration of BMS309403 improves endothelial function in apolipoprotein E-deficient mice and in cultured human endothelial cells

Background/Aims: Estrogen signalling plays an important role in vascular biology as it modulates vasoactive and metabolic pathways in endothelial cells. Growing evidence has also established microRNA (miRNA) as key regulators of endothelial function. Nonetheless, the role of estrogen regulation on miRNA profile in endothelial cells is poorly understood. In this study, we aimed to determine how estrogen modulates miRNA profile in human endothelial cells and to explore the role of the different estrogen receptors (ERα, ERβ and GPER) in the regulation of miRNA expression by estrogen. Methods: We used miRNA microarrays to determine global miRNA expression in human umbilical vein endothelial cells (HUVEC) exposed to a physiological concentration of estradiol (E2; 1 nmol/L) for 24 hours. miRNA-gene interactions were computationally predicted using Ingenuity Pathway Analysis and changes in miRNA levels were validated by qRT-PCR. Role of ER in the E2-induced miRNA was additionally confirmed by using specific ER agonists and antagonists. Results: miRNA array revealed that expression of 114 miRNA were significantly modified after E2 exposition. Further biological pathway analysis revealed cell death and survival, lipid metabolism, reproductive system function, as the top functions regulated by E2. We validated changes in the most significantly increased (miR-30b-5p, miR-487a-5p, miR-4710, miR-501-3p) and decreased (miR-378h and miR-1244) miRNA and the role of ER in these E2-induced miRNA was determined. Results showed that both classical, ERα and ERβ, and membrane-bound ER, GPER, differentially regulated specific miRNA. In silico analysis of validated miRNA promoters identified specific ER binding sites. Conclusion: Our findings identify differentially expressed miRNA pathways linked to E2 in human endothelial cells through ER, and provide new insights by which estrogen can modulate endothelial function.

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Abstract 276: Systemic Delivery of Microrna-146a Improves Endothelial Function and Ameliorates Atherosclerosis in Apolipoprotein E-deficient Mice

Circulation Research ◽

10.1161/res.117.suppl_1.276 ◽

2015 ◽

Vol 117 (suppl_1) ◽

Author(s):

Shuangtao Ma ◽

Xiao Yu Tian ◽

Chaofeng Mu ◽

Haifa Shen ◽

Yunrong Zhang ◽

...

Keyword(s):

Endothelial Function ◽

Apolipoprotein E ◽

Carotid Arteries ◽

Treated Group ◽

Vehicle Group ◽

Early Event ◽

Aortic Tissue ◽

Systemic Delivery ◽

Plaque Area ◽

Deficient Mice

Rationale: Endothelial inflammation is an early event in the development of atherosclerosis. The microRNA (miR)-146a showed anti-inflammatory effects in cultured endothelial cells. In this study, we investigated the therapeutic role of miR-146a in endothelial function and atherosclerosis in apolipoprotein E (ApoE)-deficient mice. Methods and Results: The miR-146a was packaged into a multistage vector (MSV) that was conjugated with an E-selectin-targeting thioaptamer (ESTA) to form an ESTA-MSV microparticle. The ApoE-deficient mice were fed with Western diet and injected through tail vein with 15μg of miR-146a loaded ESTA-MSV microparticles or vehicle vectors biweekly for 12 weeks. The expressions of miR-146a in aortic tissue was increased by five times at two weeks after injection. However, the expressions of miR-146a in heart, lung, liver, spleen, kidney, and skeletal muscle were not increased. The acetylcholine-induced endothelium-dependent relaxations in both carotid arteries and aortas were significantly improved in mice from miR-146a treated group compared with vehicle group. In addition, the endothelium-dependent contractions of carotid arteries were also improved by miR-146a treatment. The en face oil red O staining of whole aortas showed the plaque area was decreased in miR-146a-treated mice. Application of miR-146a also decreased the plaque size, macrophages, and T-lymphocytes, but increased the collagen deposition and vascular smooth muscle cells in the sections of aortic roots. The PCR results showed that expressions of chemokine (C-C motif) ligand (CCL)-2, CCL-5, and CCL-8 were decreased by miR-146a. Conclusions: E-selectin-targeting delivery of miR-146a improves endothelial function and inhibits atherosclerosis.

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