Microtopography Attenuates Endothelial Cell Proliferation by Regulating MicroRNAs

Dan Wang,Shuangying Gu,Mengya Liu,Song Li,Yue Zhou

doi:10.4236/jbnb.2017.83013

Abstract

Endothelial cell (EC) morphology can be regulated by the micro/nano topography in engineered vascular grafts and by hemodynamic forces in the native blood vessels. However, how EC morphology affects miRNA and thus EC functions is not well understood. In this study, we addressed this question by using human umbilical vein endothelial cells (HUVECs) cultured on microgrooves as a model. HUVECs were grown on either microgrooved (with 10 μm width/spacing and 3 μm depth) or smooth surfaces. HUVECs on microgrooved surface had elongated and bipolar morphology, while HUVECs on smooth surface showed cobble stone shape or non-polar morphology. EdU staining indicated that HUVECs with elongated morphology had lower proliferation rate compared to their counterpart cultured on smooth surface. Quantitative PCR analysis demonstrated that the expression of the specific microRNAs (miR-10a, miR-19a, miR-221) that targeted proliferation-related genes was all up-regulated. Consistently, the mRNA levels of their respective target genes, mitogen-activated protein kinase kinase kinase 7, Cyclin D1 and c-kit were significantly reduced by a fold change of 0.12 ± 0.01 (p p 0.05) and 0.76 ± 0.21 (p < 0.05). Other miRNAs such as miR-126 and miR-181a were up-regulated as well, leading to the repression of their targets vascular cell adhesion molecule-1 and prospero homeobox-1. Our results suggested that microgrooved surface may regulate microRNA levels and thus EC functions. These results provide insight into the modulation of EC functions by microtopographic cues, and will facilitate the rational design of microstructured materials for cell and tissue engineering.

Highlights

IntroductionVascular tissue engineering provides a valuable approach to replace diseased arteries [2]
How Endothelial cell (EC) morphology affects miRNA and EC functions is not well understood. We addressed this question by using human umbilical vein endothelial cells (HUVECs) cultured on microgrooves as a model
Since the water droplet was much larger than the size of the microgrooves, no significant difference was observed between the smooth surface and microgrooved surface

Summary

Introduction

Vascular tissue engineering provides a valuable approach to replace diseased arteries [2]. Many factors in the extracellular environment such as signal molecules, cellcell adhesions and extracellular matrix affect cell behaviors. Among these factors, physical cues play important roles in regulating cell functions. Micro-needles regulate cell adhesion, cell lysing and cell growth [7], and microposts accelerate the proliferation of connective tissue progenitor cells [8]. Microgrooved surfaces facilitate the derivation of cardiomyocytes from stem cells [10], affect proliferation of vascular smooth muscle cells [11] [12], and regulate cell reprogramming and epigenetic state [13] [14]. Whether and how microgrooved surface modulates microRNA and endothelial cells (EC) functions is not well understood

Methods

Results

Conclusion