Low-Intensity Pulsed Ultrasound Modulates RhoA/ROCK Signaling of Rat Mandibular Bone Marrow Mesenchymal Stem Cells to Rescue Their Damaged Cytoskeletal Organization and Cell Biological Function Induced by Radiation

Rong Zhang; Zhaoling Wang; Guoxiong Zhu; Gaoyi Wu; Qingyuan Guo; Hongchen Liu; Lei Chen

doi:10.1155/2020/8863577

Low-Intensity Pulsed Ultrasound Modulates RhoA/ROCK Signaling of Rat Mandibular Bone Marrow Mesenchymal Stem Cells to Rescue Their Damaged Cytoskeletal Organization and Cell Biological Function Induced by Radiation

Stem Cells Int. 2020 Sep 1:2020:8863577. doi: 10.1155/2020/8863577. eCollection 2020.

Authors

Rong Zhang^#^{1

2

3

4}, Zhaoling Wang^#⁵, Guoxiong Zhu⁵, Gaoyi Wu⁵, Qingyuan Guo⁶, Hongchen Liu¹, Lei Chen⁴

Affiliations

¹ Institute of Stomatology & Oral Maxilla Facial Key Laboratory, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing 100853, China.
² The Second Department of Naval Recuperation, First District of Recuperation, Armed Police Yantai Special Service Center, No. 191 Huanshan Road, Zhifu District, Yantai, Shandong Province 264000, China.
³ State Key Laboratory of Military Stomatology, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi Province 710032, China.
⁴ Department of Orthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, No. 44-1 Wenhua Road West, Jinan, Shandong Province 250012, China.
⁵ Department of Stomatology, No.960 Hospital of PLA, No. 25 Shifan Road, Jinan, Shandong Province 250000, China.
⁶ Department of Stomatology, Qingdao Municipal Hospital Group, Qingdao University, Qingdao, Shandong Province 266011, China.

^# Contributed equally.

Abstract

Osteoradionecrosis of the jaw (ORNJ) is an infrequent yet potentially devastating complication of head and neck radiation therapy. Low-intensity pulsed ultrasound (LIPUS) has been widely accepted as a promising method for the successful management of ORNJ, but the mechanism remains unclear. In this study, the effects of LIPUS on cytoskeletal reorganization, cell viability, and osteogenic differentiation capacity of rat mandible-derived bone marrow mesenchymal stem cells (M-BMMSCs) induced by radiation were determined by immunofluorescence staining, CCK-8 cell proliferation assay, quantification of alkaline phosphatase (ALP) activity, alizarin red staining, and real-time RT-PCR, respectively. Moreover, the involvement of the RhoA/ROCK signaling pathway underlying this process was investigated via western blot analysis. We found that radiation induced significant damage to the cytoskeleton, cell viability, and osteogenic differentiation capacity of M-BMMSCs and downregulated their expression of RhoA, ROCK, and vinculin while increasing FAK expression. LIPUS treatment effectively rescued the disordered cytoskeleton and redistributed vinculin. Furthermore, the cell viability and osteogenic differentiation capacity were also significantly recovered. More importantly, it could reverse the aberrant expression of the key molecules induced by radiation. Inhibition of RhoA/ROCK signaling remarkably aggravated the inhibitory effect of radiation and attenuated the therapeutic effect of LIPUS. In the light of these findings, the RhoA/ROCK signaling pathway might be a promising target for modifying the therapeutic effect of LIPUS on osteoradionecrosis.