title: [Effect of compressive stress on proliferation and apoptosis of human hyperplastic scar fibroblasts in vitro].
abstract: OBJECTIVE
  To investigate an effect of compressive stress on proliferation and apoptosis of human hyperplastic scar fibroblasts (HSFb) in vitro.
  
  
  METHODS
  HSFb were obtained from a 20-year-old female patient who developed a hyperplastic scar 3 months after operation for a large-area burn. HSFb were isolated, and were cultured in vitro with the simplified air-pressure controlled cell-culture instrument, and then they were randomly divided into the following 8 groups: the control group (no stress) and the 7 continuous compressive stress groups, which respectively underwent the 5, 10, 15, 25, 50, 100 and 150 mmHg (1 mmHg = 0.133 kPa) pressure treatment for 4 days. The absorbance (A) of the cell and the inhibition ratio (IR) of the cell proliferation were determined by the MTT assay, the cell growth cycle was determined by the flow cytometer, and the cell apoptosis was observed by the Annexin V binding with PI labeling method.
  
  
  RESULTS
  In the 5, 10, 15, 25, 50, 100 and 150 mmHg pressure groups and the control group, the A values of the cells were 0.228 +/- 0.004, 0.226 +/- 0.003, 0.213 +/- 0.005, 0.180 +/- 0.005, 0.172 +/- 0.007, 0.165 +/- 0.004, 0.164 +/- 0.004 and 0.230 +/- 0.005, respectively; the IRs of the cell proliferation were 0.8%, 2.0%, 7.3%, 21.7%, 25.2%, 28.2% and 0, respectively; the ratios of the cells in G1 were 71.80% +/- 0.44%, 72.32% +/- 0.40%, 74.56% +/- l.01%, 82.82% +/- 2.76%, 86.77% +/- 2.06%, 88.23% +/- 1.27%, 89.11% +/- 1.74% and 71.46% +/- 0.49%, respectively; the cell apoptosis ratios were 4.22% +/- 0.49%, 5.12% +/- 0.74%, 8.58% +/- 0.79%, 19.28% +/- 1.40%, 25.60% +/- 1.21%, 35.80% +/- 2.39%, 36.18% +/- 2.38% and 4.00% +/- 0.36%, respectively. In the 5 and 10 mmHg groups there were no statistically significant differences in all the above parameters when compared with those in the control group (P > 0.05); however, in the 15, 25, 50, 100 and 150 mmHg groups there were statistically significant differences in the above parameters when compared with those in the control group (P < 0.05). Furthermore, in the 10, 15, 25 and 50 mmHg groups, there were statistically significant differences in the A value of the cells and the ratios of the cells in G1 when compared with each other (P < 0.01). By contrast, there were no statistically significant differences in the 50, 100 and 150 mmHg groups when compared with each other (P > 0.05). In the 10, 15, 25, 50 and 100 mmHg groups there were statistically significant differences in the cell apoptosis ratio when compared with each other (P < 0.01). In the 100 and 150 mmHg groups there were no such statistically significant differences when compared with each other (P > 0.05).
  
  
  CONCLUSIONS
  A continuous compressive stress when given properly can have a combined effect of the proliferation inhibition and the apoptosis promotion on HSFb in vitro, and this kind of combined effects can become one of the important mechanisms for the pressure therapy in treating hyperplastic scar.
authors.affiliation: Department of Plastic and Reconstructive Surgery, Southwest Hospital, Third Military Medical University, Chongqing, 400038, PR China. XH_SMMUPLA@126.com
authors.forename: Hong
authors.initials: H
authors.lastname: Xiao
authors.forename: Jianfu
authors.initials: J
authors.lastname: Li
mesh_terms: D017209:Apoptosis; D049109:Cell Proliferation; D002478:Cells, Cultured; D017439:Cicatrix, Hypertrophic / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005347:Fibroblasts / Q000473:pathology; D005434:Flow Cytometry; D006801:Humans; D013314:Stress, Mechanical; D055815:Young Adult