Wnt10b-overexpressing umbilical cord mesenchymal stem cells promote critical size rat calvarial defect healing by enhanced osteogenesis and VEGF-mediated angiogenesis

Yong Liu; Jiarui Fang; Quan Zhang; Xiaoguang Zhang; Yulin Cao; Wei Chen; Zengwu Shao; Shuhua Yang; Dongcheng Wu; Man Hung; Yingze Zhang; Wei Tong; Hongtao Tian

doi:10.1016/j.jot.2020.02.009

Wnt10b-overexpressing umbilical cord mesenchymal stem cells promote critical size rat calvarial defect healing by enhanced osteogenesis and VEGF-mediated angiogenesis

J Orthop Translat. 2020 Mar 28:23:29-37. doi: 10.1016/j.jot.2020.02.009. eCollection 2020 Jul.

Authors

Yong Liu¹, Jiarui Fang¹, Quan Zhang², Xiaoguang Zhang¹, Yulin Cao¹, Wei Chen³, Zengwu Shao¹, Shuhua Yang¹, Dongcheng Wu^{2

4}, Man Hung⁵, Yingze Zhang³, Wei Tong¹, Hongtao Tian¹

Affiliations

¹ Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277, Jiefang Avenue, Wuhan, Hubei, 430022, China.
² Wuhan Hamilton Biotechnology Co., Ltd, Wuhan, Hubei, 430075, China.
³ The Third Hospital of Hebei Medical University, 139, Ziqiang Road, Shi Jiazhuang, Hebei, 050051, China.
⁴ Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Wuhan University, China.
⁵ College of Dental Medicine, Roseman University of Health Sciences, 10984 S River Front Pkwy, South Jordan, UT, 84095, USA.

Abstract

Background/objectives: Accelerating the process of bone regeneration is of great interest for surgeons and basic scientists alike. Recently, umbilical cord mesenchymal stem cells (UCMSCs) are considered clinically applicable for tissue regeneration due to their noninvasive harvesting and better viability. Nonetheless, the bone regenerative ability of human UCMSCs (HUCMSCs) is largely unknown. This study aimed to investigate whether Wnt10b-overexpressing HUCMSCs have enhanced bone regeneration ability in a rat model.

Method: A rat calvarial defect was performed on 8-week old male Sprague Dawley rats. Commercially purchased HUCMSCs^Emp in hydrogel, HUCMSCs^Wnt10b in hydrogel and HUCMSCs^Wnt10b with IWR-1 were placed in the calvarial bone defect right after surgery on rats (N = 8 rats for each group). Calvaria were harvested for micro-CT analysis and histology four weeks after surgery. CFU-F and multi-differentiation assay by oil red staining, alizarin red staining and RT-PCR (real-time polymerase chain reaction) were performed on HUCMSCs^Emp and HUCMSCs^Wnt10b in vitro. Conditioned media from HUCMSCs^Emp and HUCMSCs^Wnt10b were collected and used to treat human umbilical cord vein endothelial cells in Matrigel to access vessel formation capacity by tube formation assay.

Results: Alizarin red staining, oil red staining and RT-PCR results showed robust osteogenic differentiation but poor adipogenic differentiation ability of HUCMSCs^Wnt10b. Furthermore, HUCMSCs^Wnt10b could accelerate bone defect healing, which was likely due to enhanced angiogenesis after the HUCMSCs^Wnt10b treatment, because more CD31+ vessels and increased vascular endothelial growth factor-A (VEGF-A) expression were observed, compared with the HUCMSCs^Emp treatment. Conditioned media from HUCMSCs^Wnt10b also induced endothelial cells to form vessel tubes in a tube formation assay, which could be abolished by SU5416, an angiogenesis inhibitor.

Conclusion: To our knowledge, this is the first study providing empirical evidence that HUCMSCs^Wnt10b can enhance their ability to heal calvarial bone defects via VEGF-mediated angiogenesis.

The translational potential of this article: HUCMSCs^Wnt10b can accelerate critical size calvaria and are a new promising therapeutic cell source for fracture nonunion healing.

Keywords: Angiogenesis; Bone regeneration; Umbilical cord MSCs; Wnt signalling pathway.