Research Paper|Volume 13, Issue 3|pp 4199—4214

Long non-coding RNA (LncRNA) HOTAIR regulates BMP9-induced osteogenic differentiation by targeting the proliferation of mesenchymal stem cells (MSCs)

Ruidong Li^1,², Wenwen Zhang^2,³, Zhengjian Yan^1,², Wei Liu^2,⁴, Jiaming Fan^2,⁶, Yixiao Feng^2,⁵, Zongyue Zeng^2,⁶, Daigui Cao^1,^2,⁷, Rex C. Haydon², Hue H. Luu², Zhong-Liang Deng^1,², Tong-Chuan He², Yulong Zou^1,²

¹Department of Orthopaedic Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
²Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, IL 60637, USA
³Department of Obstetrics and Gynecology, The Affiliated University-Town Hospital of Chongqing Medical University, Chongqing 401331, China
⁴Department of Orthopaedic Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
⁵Department of Breast Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
⁶Ministry of Education Key Laboratory of Diagnostic Medicine, Chongqing Medical University, Chongqing 400016, China
⁷Department of Orthopaedic Surgery, Chongqing General Hospital, Chongqing 400021, China

Received: July 13, 2020Accepted: November 17, 2020Published: January 10, 2021

https://doi.org/10.18632/aging.202384

Copyright: © 2021 Li et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Long non-coding RNAs are important regulators of biological processes, but their roles in the osteogenic differentiation of mesenchymal stem cells (MSCs) remain unclear. Here we investigated the role of murine HOX transcript antisense RNA (mHotair) in BMP9-induced osteogenic differentiation of MSCs using immortalized mouse adipose-derived cells (iMADs). Touchdown quantitative polymerase chain reaction analysis found increased mHotair expression in bones in comparison with most other tissues. Moreover, the level of mHotair in femurs peaked at the age of week-4, a period of fast skeleton development. BMP9 could induce earlier peak expression of mHotair during in vitro iMAD osteogenesis. Silencing mHotair diminished BMP9-induced ALP activity, matrix mineralization, and expression of osteogenic, chondrogenic and adipogenic markers. Cell implantation experiments further confirmed that knockdown of mHotair attenuated BMP9-induced ectopic bone formation and mineralization of iMADs, leading to more undifferentiated cells. Crystal violet staining and cell cycle analysis revealed that silencing of mHotair promoted the proliferation of iMAD cells regardless of BMP9 induction. Moreover, ectopic bone masses developed from mHotair-knockdown iMAD cells exhibited higher expression of PCNA than the control group. Taken together, our results demonstrated that murine mHotair is an important regulator of BMP9-induced MSC osteogenesis by targeting cell cycle and proliferation.