Effects of Low-Intensity Pulsed Ultrasound on the Expression and Activity of Hyaluronan Synthase and Hyaluronidase in IL-1β-Stimulated Synovial Cells

Abstract

The purpose of this study is to examine effects of low-intensity pulsed ultrasound (LIPUS) on metabolism of hyaluronan (HA) in synovial membrane cells stimulated by IL-1β. Rabbit knee synovial membrane cell line, HIG-82, was cultured in medium with the presence or absence of 1 ng/mL IL-1β, and after 4 h the cell was exposed to LIPUS for 15 min. The mRNA levels of HA synthase (HAS) 2,3, hyaluronidase (HYAL) 2, and cyclooxygenase (COX)-2 were examined by real-time PCR analysis. Concentrations of HA and PGE₂ were quantified by use of enzyme linked immunosorbent assay (ELISA). The COX-2 level was analyzed by western blotting. Gene levels of HAS2 and HAS3 in IL-1β-stimulated cells were up-regulated significantly (p < 0.01) by LIPUS. HYAL2 mRNA was up-regulated by the treatment with IL-1β, whereas down-regulated significantly (p < 0.01) by the following LIPUS exposure. Furthermore, IL-1β stimulation enhanced COX-2 and PGE₂ expression as compared to the untreated control, and IL-1β-induced COX-2 and PGE₂ expression was inhibited by LIPUS. These results suggest that LIPUS enhanced HA synthesis and inhibited HYAL2 expression, leading to the accumulation of high-molecular weight HA. Therefore, LIPUS stimulation may be a better candidate as medical remedy to treat inflammatory joint diseases accompanied with HA degradation in synovial fluid.

Effects of Payena dasyphylla (Miq.) on hyaluronidase enzyme activity and metalloproteinases protein expressions in interleukin-1β stimulated human chondrocytes cells

“…However, results from both the mRNA expression of the hyaluronidases shows that HYAL1 and HYAL2 are up-regulated by the treatment of IL-1β. This is in accordance with the study done by Nakamura et al, [25]. Findings from this data demonstrates that treatment with P. dasyphylla EA extract in response to human IL-1β has proven to be potential inhibiting the two principle hyaluronidases.…”

Low-Intensity Pulsed Ultrasound Reduces the Inflammatory Activity of Synovitis

“…22 In addition, It was reported that LIPUS down-regulated the expression of Cox-2 mRNA in chondrocytes as well as synovial membrane cells (Y. Iwabuchi, Personal communication). In the present study, we showed that the expression of Cox-2 in the knee joints of MRL/lpr mice was markedly reduced by daily LIPUS exposure in vivo.…”

“…13 To the best of our knowledge, this is the first attempt to investigate the effects of LIPUS on the cell proliferation and growth of synovial membrane cells. The only available information about its effect on synovial membrane cells is from our previous study, 22 in which the effect of LIPUS on the IL-1b-stimulated metabolism of hyaluronic acid in synovial membrane cells was examined. We showed that gene and protein expression of Cox-2 as well as PGE 2 secretion were increased in the HIG-82 synovial membrane cell line following stimulation with IL-1b, and that the increased expression of Cox-2 was significantly inhibited by subsequent LIPUS exposure.…”

“…22 Therefore, we next examined Cox-2 expression in the knee joint of MRL/lpr mice treated with LIPUS in vivo. As shown in Fig.…”

“…33 Furthermore, various cell types have been reported to be sensitive to ultrasound exposure, including periodontal ligament cells, 12,15 cementoblastic cells, 6,7 chondrocytes, 32 bone cells, 23 and synovial membrane cells. 22 We previously demonstrated 22 that LIPUS downregulates Cox-2 and PGE 2 expression in IL-1b-stimulated synovial membrane cells in vitro. Since LIPUS provides mechanical stimulation to the cellular system, the mechanical stimulation induced by LIPUS may modulate synovial inflammation.…”