Abstract:

BACKGROUND: Mechanical strain plays a key role in cell proliferation, differentiation, apoptosis and gene expression.
OBJECTIVE: To investigate mechanical strain effects on the formation of hypertrophic scar and hydroxyproline content in mice.
METHODS: Four weeks old C57/BL mice were randomly divided into mechanical strain group and control group. The mice in the mechanical strain group were subjected to a 2-cm full-thickness skin incision, and then sutured with nylon wire. After stitches were taken out at day 4, 222-cm-mm stretching screw was fixed on the healed wound with nylon wire and expanded every other day. While stretching screw in the control group had no treatment. Six mice in each group were collected respectively at weeks 1, 2, 3, 4 and 5 after wounded, and then their hypertrophic scar thickness, cross-sectional area changes and hydroxyproline content in the hypertrophic scar tissues were observed.
RESULTS AND CONCLUSION: Compared with the control group, scar hyperplasia in the mechanical strain group was more obvious, besides, the thickness, cross-sectional area of hypertrophic scars was bigger (P < 0.01). Hydroxyproline content in the hypertrophic scar tissues of the mechanical strain group was significantly higher than that in the control group at each time point (P < 0.01). These results suggest that mechanical strain can result in obvious scar hyperplasia in mice and a significant increase in hydroxyproline content.