Low-Intensity Pulsed Ultrasound Alleviates Osteoarthritis Condition Through Focal Adhesion Kinase-Mediated Chondrocyte Proliferation and Differentiation.

Author: Sang F1, Xu J2, Chen Z3, Liu Q1, Jiang W4
Affiliation: <sup>1</sup>Department of Orthopaedics, Lianshui County People's Hospital, The Affiliated Lianshui County People's Hospital of Kangda College of Nanjing Medical University, Huai'an, Jiangsu, China. <sup>2</sup>Department of Orthopaedics, The Affiliated Huai'an Hospital of Xuzhou Medical University and The Second People's Hospital of Huai'an, Huai'an, Jiangsu, China. <sup>3</sup>Department of Emergency Surgery, The Affiliated Huai'an No. 1 People's Hospital of Nanjing Medical University, Huai'an, Jiangsu, China. <sup>4</sup>Department of Orthopaedics, Wujin Hospital Affiliated with Jiangsu University, the Wujin Clinical College of Xuzhou Medical University, Changzhou, Jiangsu, China.
Conference/Journal: Cartilage.
Date published: 2020 Apr 13
Other: Volume ID: 1947603520912322 , Special Notes: doi: 10.1177/1947603520912322. [Epub ahead of print] , Word Count: 219

OBJECTIVE: Osteoarthritis (OA) is a prevalent chronic multifactorial degenerative disease characterized by joint tissue inflammation, osteophyte formation, subchondral bone sclerosis, and articular cartilage degradation. Low-intensity pulsed ultrasound (LIPUS), a noninvasive ultrasound technique, is widely used to attenuate diseases. The aim of this study was to investigate whether LIPUS can ameliorate OA, and to explore its underlying molecular mechanism.

DESIGN: The OA model was established in a C57BL/6 mouse by the anterior cruciate ligament transaction method. OA was assessed using arthritis scoring and weightbearing parameters. Chondrocyte proliferation was detected by a CCK-8 assay. The levels of interleukin-6 (IL-6), IL-8 and tumor necrosis factor-α (TNF-α) in synovial fluid of the mice were measured by enzyme-linked immunosorbent assay.

RESULTS: In OA mice, the arthritis score and weightbearing abilities were dramatically improved by LIPUS treatment. LIPUS also remarkably declined the levels of inflammatory cytokines IL-6, IL-8, and TNF-α in synovial fluid of OA mice. Moreover, LIPUS promoted chondrocyte proliferation and differentiation by activating focal adhesion kinase (FAK) signaling. Inhibition of FAK significantly blocked LIPUS-mediated cell proliferation and differentiation in vitro, as well as inflammation condition in OA mice.

CONCLUSION: LIPUS alleviates OA through promoting chondrocytes proliferation and differentiation by activating FAK, which could act as an intervening target for OA treatment.

KEYWORDS: chondrocytes; focal adhesion kinase; low-intensity pulsed ultrasound; osteoarthritis

PMID: 32281401 DOI: 10.1177/1947603520912322