Lower energy radial shock wave therapy improves characteristics of hypertrophic scar in a rabbit ear model
- Jing‑Chun Zhao
- Bo‑Ru Zhang
- Kai Shi
- Jian Wang
- Qing-Hua Yu
- Jia‑Ao Yu
Published online on: November 6, 2017
Copyright: © Zhao et al.
This is an open access article distributed under the terms of Creative Commons Attribution License.
The aim of the present study was to investigate the effects of radial extracorporeal shock wave therapy (rESWT) on scar characteristics and transforming growth factor (TGF)‑β1/Smad signaling in order to explore a potential modality for the treatment of hypertrophic scars (HS). The HS model was generated in rabbit ears, then rabbits were randomly divided into 3 groups: Lower (L)‑ESWT [treated with rESWT with lower energy flux density (EFD) of 0.1 mJ/mm2], higher (H)‑ESWT (treated with a higher EFD of 0.18 mJ/mm2) and the sham ESWT group (S‑ESWT; no ESWT treatment). Scar characteristics (wrinkles, texture, diameter, area, volume of elevation, hemoglobin and melanin) were assessed using the Antera 3D® system. The protein and mRNA expression of TGF‑β1, Smad2, Smad3 and Smad7 was assessed by enzyme‑linked immunosorbent assay and reverse transcription‑quantitative polymerase chain reaction, respectively. The Antera 3D® results indicated that wrinkles and hemoglobin of the HS were significantly improved in both of the rESWT groups when compared with the S‑ESWT group. However, these changes appeared much earlier in the L‑ESWT group than the H‑ESWT. Scar texture was also improved in the L‑ESWT group. However, rESWT did not influence HS diameter, area, volume of elevation or melanin levels. rESWT had no effect on TGF‑β1 or Smad7 expression in either of rESWT groups. Although no difference was observed in Smad2 mRNA expression in the L‑ESWT group, the Smad3 mRNA and protein expression significantly decreased when compared with the H‑ESWT and S‑ESWT groups. By contrast, Smad2 and Smad3 mRNA expression were upregulated in the H‑ESWT group. These results demonstrated that rESWT with 0.1 mJ/mm2 EFD improved some characteristics of the HS tissue. Downregulation of Smad3 expression may underlie this inhibitory effect. Inhibition of the TGF‑β1/Smad signal transduction pathway may be a potential therapeutic target for the management of HS.