title: Effects of Shock Waves on Expression of IL-6, IL-8, MCP-1, and TNF-α Expression by Human Periodontal Ligament Fibroblasts: An In Vitro Study.
abstract: BACKGROUND
  Extracorporeal shock wave therapy (ESWT) can modulate cell behavior through mechanical information transduction. Human periodontal ligament fibroblasts (hPDLF) are sensible to mechanical stimulus and can express pro-inflammatory molecules in response. The aim of this study was to evaluate the impacts of shock waves on interleukin-6 (IL-6), interleukin-8 (IL-8), monocyte chemotactic protein 1 (MCP-1), and tumor necrosis factor-alpha (TNF-α) expression by hPDLF.
  
  
  METHODS
  After being treated by shock waves with different parameters (100-500 times, 0.05-0.19 mJ/mm(2)), cell viability was tested using CCK-8. IL-6, IL-8, MCP-1, and TNF-α gene expression was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) and IL-6 and IL-8 protein was measured by enzyme-linked immunosorbent assay (ELISA) at different time points.
  
  
  RESULTS
  Shock waves with the parameters used in this study had no significant effects on the viability of hPDLF. A statistical inhibition of IL-6, IL-8, MCP-1, and TNF-α expression during the first few hours was observed (P<0.05). Expression of IL-8 was significantly elevated in the group receiving the most pulses of shock wave (500 times) after 4 h (P<0.05). At 8 h and 24 h, all treated groups demonstrated significantly enhanced IL-6 expression (P<0.05). TNF-α expression in the groups receiving more shock pulses (300, 500 times) or the highest energy shock treatment (0.19 mJ/mm(2)) was statistically decreased (P<0.05) at 24 h.
  
  
  CONCLUSIONS
  Under the condition of this study, a shock wave with energy density no higher than 0.19 mJ/mm(2) and pulses no more than 500 times elicited no negative effects on cell viability of hPDLF. After a uniform initial inhibition impact on expression of inflammatory mediators, a shock wave could cause dose-related up-regulation of IL-6 and IL-8 and down-regulation of TNF-α.
authors.affiliation: School and Hospital of Stomatology, Fujian Medical University, Fuzhou, Fujian, China (mainland).
authors.forename: Zhiyu
authors.initials: Z
authors.lastname: Cai
authors.affiliation: Department of Orthodontics, Bernhard Gottlieb University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria.
authors.forename: Frank
authors.initials: F
authors.lastname: Falkensammer
authors.affiliation: Competence Centre of Periodontal Research, Bernhard Gottlieb School of Dentistry, Medical University of Vienna, Vienna, Austria.
authors.forename: Oleh
authors.initials: O
authors.lastname: Andrukhov
authors.affiliation: School and Hospital of Stomatology, Fujian Medical University, Fuzhou, Fujian, China (mainland).
authors.forename: Jiang
authors.initials: J
authors.lastname: Chen
authors.affiliation: The Austrian Cluster for Tissue Regeneration, Ludwig Boltzmann Institute for Experimental and Clinical Traumatology/Austrian Workers' Compensation Board (AUVA) Research Center, Vienna, Austria.
authors.forename: Rainer
authors.initials: R
authors.lastname: Mittermayr
authors.affiliation: Competence Centre of Periodontal Research, Bernhard Gottlieb School of Dentistry, Medical University of Vienna, Vienna, Austria.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Rausch-Fan
mesh_terms: D000293:Adolescent; D049109:Cell Proliferation; D002470:Cell Survival / Q000235:genetics; D018932:Chemokine CCL2 / Q000235:genetics* / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D005786:Gene Expression Regulation; D019220:High-Energy Shock Waves; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics* / Q000378:metabolism; D016209:Interleukin-8 / Q000235:genetics* / Q000378:metabolism; D008297:Male; D010513:Periodontal Ligament / Q000166:cytology*; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics* / Q000378:metabolism
chemical_list: C111835:CCL2 protein, human; C508606:CXCL8 protein, human; D018932:Chemokine CCL2; C508600:IL6 protein, human; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha