Abstract: 【Abstract】 Objective To preliminarily evaluate the effect of tension stimulation on the biological activity of and expression of fibrosis marker genes in keloid fibroblasts （KD-Fbs）. Methods Three patients who were diagnosed with keloids and received surgical treatment were collected from the Department of Dermatology, Tangdu Hospital, the Fourth Military Medical University from January to March 2017. Human KD-Fbs were isolated from resected keloid tissues, and subjected to primary culture. The third- to sixth-passage KD-Fbs were divided into tension group and control group to be cultured in the tension-based chamber and control chamber respectively, and subjected to tension stimulation and normal culture respectively. Cell counting kit-8 （CCK8） assay was performed to assess the proliferative activity of KD-Fbs after 1-, 2-, 3- and 4-day culture, and the scratch assay to evaluate the migratory ability of KD-Fbs after 1- and 2-day culture. After 48-hour treatment, real-time quantitative PCR and Western blot analysis were performed to determine the mRNA and protein expression of fibrosis markers typeⅠcollagen, fibronectin and α-smooth muscle actin （α-SMA） in KD-Fbs respectively. Two-independent-sample t test was used for comparisons between 2 groups. Results CCK8 assay showed that the proliferative activity of KD-Fbs was significantly higher in the tension group than in the control group after 1-, 2-, 3- and 4-day culture （t = 3.05, 7.00, 16.65, 15.19, respectively, all P < 0.05）. After 1- and 2-day culture, the scratch assay showed that the migration rate of KD-Fbs was significantly higher in the tension group （48.65% ± 3.96%, 100.00%, respectively） than in the control group （9.36% ± 1.14%, 50.35% ± 4.23%, t = 16.53, 20.35, respectively, both P < 0.01）. Real-time quantitative PCR showed that the mRNA expression of typeⅠcollagen, fibronectin and α-SMA was significantly higher in the tension group （3.04 ± 0.20, 2.16 ± 0.10, 3.76 ± 0.24, respectively） than in the control group （1.00; t = 17.57, 21.01, 20.25, respectively, all P < 0.01）. As Western blot analysis revealed, changes in the protein expression of the 3 fibrosis markers were consistent with their mRNA expression changes （all P < 0.05）. Conclusion Tension may participate in the fibrosis in keloids by promoting the expression of fibrosis marker genes, and enhancing the proliferative and migratory ability of KD-Fbs.

Key words: Keloid, Fibrosis, Cell proliferation, Cell migration assays, Tension