title: [Effect of melatonin on proliferation and apoptosis of fibroblasts in human hypertrophic scar].
abstract: OBJECTIVE
  To study the effect of melatonin on proliferation and apoptosis of fibroblasts in human hypertrophic scar and its mechanism.
  
  
  METHODS
  Fibroblasts from human hypertrophic scar were isolated and cultured with DMEM medium containing 10% FBS, and then they were divided into control (C, added with ethanol), low concentration (LC, added with 1 × 10(-5) mmol/L melatonin), middle concentration (MC, added with 1 × 10(-3) mmol/L melatonin), and high concentration (HC, added with 1 mmol/L melatonin) groups according to the random number table. After being cultured for 24 hours, cell morphologic change was observed under microscope; XTT-PMS assay was used to examine cell proliferative activity; cell cycle and apoptosis were assessed with flow cytometry after double staining of FITC and PI, and the levels of cyclin E, p53, and Fas mRNA were determined with fluorescence quantitative RT-PCR. Data were processed with analysis of variance and LSD test.
  
  
  RESULTS
  (1) Fibroblasts in C group were spindle-shaped with growth in colonies. Along with the increase in melatonin concentration, fibroblasts in LC, MC, and HC groups gradually dispersed, deformed and atrophied, with shrunk cellular membrane, and decrease in ratio of nucleus and cytoplasm. (2) Proliferative activity of fibroblasts in LC, MC, and HC groups decreased along with an increase in melatonin concentration (1.49 ± 0.15, 1.24 ± 0.20, and 0.92 ± 0.09), which were lower that in C group (1.79 ± 0.10, F = 67.61, P < 0.05). Cell ratios of S and G2/M phases in LC, MC, and HC groups decreased along with an increase in melatonin concentration, which were all lower than those in C group [(10.6 ± 1.1)%, (6.1 ± 1.2)%, (3.2 ± 0.8)% vs.(16.9 ± 1.3)%, F = 286.10, P < 0.05; (13.5 ± 1.1)%, (9.8 ± 1.0)%, (6.0 ± 0.7)% vs. (16.7 ± 1.6)%, F = 162.69, P < 0.05]. Apoptotic rates in early and late stages of LC, MC, and HC groups increased along with an increase in melatonin concentration, all higher than those in C group (with F value respectively 424.05, 236.44, P values all below 0.05). The expressions of cyclin E mRNA in LC, MC, and HC groups decreased along with an increase in melatonin concentration, which were lower than that in C group (1.58 ± 0.21, 0.90 ± 0.20, and 0.24 ± 0.12 vs. 2.90 ± 0.30, F = 266.79, P < 0.05), while the expressions of p53 mRNA and Fas mRNA showed opposite tendency (with F value respectively 10.11, 12.03, P values all below 0.05).
  
  
  CONCLUSIONS
  Melatonin can inhibit proliferation and induce apoptosis of fibroblasts in hypertrophic scar through regulating the gene expressions of cyclin E, p53, and Fas.
authors.affiliation: Department of Burns and Plastic Surgery, Ji'nan University Medical School, Guangzhou, China.
authors.forename: You-fu
authors.initials: YF
authors.lastname: Xie
authors.forename: Jun-cheng
authors.initials: JC
authors.lastname: Zhang
authors.forename: Si-jun
authors.initials: SJ
authors.lastname: Liu
authors.forename: Li-bing
authors.initials: LB
authors.lastname: Dai
authors.forename: Gao-wei
authors.initials: GW
authors.lastname: Du
mesh_terms: D000328:Adult; D017209:Apoptosis / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D017439:Cicatrix, Hypertrophic / Q000378:metabolism / Q000473:pathology*; D019927:Cyclin E / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D015513:Oncogene Proteins / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D019014:fas Receptor / Q000378:metabolism
chemical_list: C475820:CCNE1 protein, human; D019927:Cyclin E; C491901:FAS protein, human; D015513:Oncogene Proteins; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D019014:fas Receptor; D008550:Melatonin