The Mechanosensing and Global DNA Methylation of Human Osteoblasts on MEW Fibers.

Pingping Han,Abdalla Abdal-Hay,Sašo Ivanovski,Cedryck Vaquette

doi:10.3390/nano11112943

Pingping Han, Abdalla Abdal-Hay + Show 2 more

Open Access

https://doi.org/10.3390/nano11112943

Copy DOI

Journal: Nanomaterials	Publication Date: Nov 3, 2021
Citations: 9	License type: CC BY 4.0

Affiliation: University of Queensland, South Valley University

Abstract

Cells interact with 3D fibrous platform topography via a nano-scaled focal adhesion complex, and more research is required on how osteoblasts sense and respond to random and aligned fibers through nano-sized focal adhesions and their downstream events. The present study assessed human primary osteoblast cells’ sensing and response to random and aligned medical-grade polycaprolactone (PCL) fibrous 3D scaffolds fabricated via the melt electrowriting (MEW) technique. Cells cultured on a tissue culture plate (TCP) were used as 2D controls. Compared to 2D TCP, 3D MEW fibrous substrates led to immature vinculin focal adhesion formation and significantly reduced nuclear localization of the mechanosensor-yes-associated protein (YAP). Notably, aligned MEW fibers induced elongated cell and nucleus shape and highly activated global DNA methylation of 5-methylcytosine, 5-hydroxymethylcytosine, and N-6 methylated deoxyadenosine compared to the random fibers. Furthermore, although osteogenic markers (osterix-OSX and bone sialoprotein-BSP) were significantly enhanced in PCL-R and PCL-A groups at seven days post-osteogenic differentiation, calcium deposits on all seeded samples did not show a difference after normalizing for DNA content after three weeks of osteogenic induction. Overall, our study linked 3D extracellular fiber alignment to nano-focal adhesion complex, nuclear mechanosensing, DNA epigenetics at an early point (24 h), and longer-term changes in osteoblast osteogenic differentiation.

Highlights

Published: 3 November 2021In the native bone milieu, osteoblasts can sense their local structural microenvironment to form focal adhesions and initiate “outside-in” mechanotransductive signals, leading to extracellular matrix formation along the cellular direction [1,2,3]
The results showed that PCL-A group had significantly increased gene expression of osteogenic markers such as alkaline phosphatase (ALP), OSX, and BSP compared to 2D tissue culture plate (TCP)
Our results showed a different trend that lower nuclear yes-associated protein (YAP) and fewer focal adhesion (FAs) (24 h post-seeding) in the PCL-A group led to higher gene expression of early osteogenic markers (7-day post osteogenic differentiation), with no change in calcium mineralization after 3-week osteogenic induction

Summary

Introduction

Published: 3 November 2021In the native bone milieu, osteoblasts can sense their local structural microenvironment to form focal adhesions and initiate “outside-in” mechanotransductive signals, leading to extracellular matrix formation along the cellular direction [1,2,3]. Forces that are generated by nano-scaled FAs (such as vinculin [10]) are transmitted to the cytoplasm, nucleus (via nuclear mechanosensor–YAP/TAZ [11]) and chromatin, through physical links on the nuclear membrane and the mesh-structured nuclear Lamin A/C network [12]. This process, in turn, may govern epigenetic mechanisms, Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations

Methods

Findings

Discussion

Conclusion