Shockwaves Inhibit Chondrogenic Differentiation of Human Mesenchymal Stem Cells in Association with Adenosine and A2B Receptors

Lei Tan,Da-Hui Sun,Fu-Tao Ge,Tiecheng Yu,Bin Zhao

doi:10.1038/s41598-017-14875-y

Abstract

Extracorporeal shockwave therapy (ESWT) has emerged as the important choice for the treatment of many orthopedic disorders. Our previous mechanistic studies suggest that ESWT promoted osteogenesis of human mesenchymal stem cells (hMSCs) through mechanisms that involve adenosine 5′-triphosphate (ATP) release. In this study, we investigated the effect of ESWT on chondrogenesis of hMSCs. We demonstrate that ESWT treatment caused a significant release of adenosine from hMSCs; ESWT treatment increased the levels of A2B receptor (A2BR) in hMSCs under 3-D culture conditions. ESWT, exogenous adenosine and specialized A2BR agonist suppressed hMSC chondrogenic differentiation through downregulating the expressions of aggrecan (ACAN), Collagen Type I alpha 2(COL1A2), Collagen Type II alpha 1(COL2A1), Sex-Determining Region YBox 9 (SOX9) and Sex-Determining Region YBox 6 (SOX6). Selective A2BR antagonists induced chondrogenic differentiation of hMSCs. This study indicated that shockwave therapy inhibits hMSC chondrogenic differentiation through or partially through regulation of adenosine release and activation of A2B receptor under 3-D culture conditions.

Highlights

In the past decades, extracorporeal shockwave therapy (ESWT) had emerged as the important choice in the treatment of many orthopedic disorders including shoulder pathology, chronic diabetic foot ulcers, osteoarthritis of the knee, chronic patellar tendinopathy, bone nonunion and avascular necrosis of the femoral head[6,7,8,9,10,11]
There were no significant differences for adenosine 5′-triphosphate (ATP), ADP and AMP compared with the 200 impulses group (Fig. 1), while the release of adenosine increased significantly (p < 0.01)
Our previous study showed that shockwaves released cellular ATP that activated P2 × 7 receptors and downstream signaling events and promoted osteogenic differentiation of hMSCs13

Summary

Introduction

Extracorporeal shockwave therapy (ESWT) had emerged as the important choice in the treatment of many orthopedic disorders including shoulder pathology, chronic diabetic foot ulcers, osteoarthritis of the knee, chronic patellar tendinopathy, bone nonunion and avascular necrosis of the femoral head[6,7,8,9,10,11]. Our recent study suggested that the mechanism of shockwave promoting osteogenesis may be related to adenosine 5′-triphosphate (ATP)[13]. Adenosine may be an important factor in the biological effects of shockwaves. Adenosine in the extracellular compartment functions as a signaling molecule through the activation of G-protein-coupled receptors. Four distinct adenosine receptors (ARs) have been described, A1, −2A, -2B, and -3, which differ in their affinity for adenosine and the biological effects of their associated signaling pathways[14]. A2BR signaling pathway can stimulate the production of IL-6, which may have an important role in the differentiation of MSCs. In this study, we investigated the effect of shockwave treatment on hMSCs chondrogenesis and explored the potential mechanisms.

Methods

Results

Conclusion