Change of alpha-SM Actin Expression Induced by the Antibody for TGF-beta in Fibroblast NIH3T3 Culture: The basic research for the inhibition of wound contracture

PURPOSE: The purpose of this experiment is to measure the expression of TGF-beta and alpha-SM actin (smooth muscle actin) from fibroblast culture by the duration of culture days and to analyze the inhibition of alpha-SM actin expression in fibroblast by the antibodies for TGF-beta. METHODS: The levels of alpha-SM actin from the paired NIH3T3 cell cultures with TGF-beta 1 containing medium (10 ng/ml) and with the antibody (for TGF-beta) medium (1 or 2 ug/ml) were determined by SDS PAGE for cell lysate protein, Western blot with ECL autoradiography and immuno - slot blot. RESULTS: In NIH3T3 culture, the expression of alpha-SM actin increased at culture days 4, 5, 6. TGF-beta was expressed from 2nd day of culture and increased by day 7. The addition of TGF beta (10 ng/ml) did not increased the expression of alpha-SM actin. But alpha-SM actin expression decreased in the presence of anti-TGF beta antibody. The decrease of expression was proportional to the concentration of antibody and duration of exposure to the antibody. CONCLUSIONS: Endogenous TGF-beta produced by fibroblast cultures is sufficient to express the alpha-SM actin from the myofiboblast. There was no additive expression of alpha-SM actin with exogenous TGF-beta 1. The antibody for TGF- beta inhibits the production of the alpha-SM actin during wound healing and may prevent the wound contracture.

The Experimantal Studey of Delayed Wound Healing on Full-Thickness Skin Defects in Diabetic Rats

Wound healing was a natural process proceeded by connective tissue deposition, epithelialization, and wound contracture. Streptozotocin-induced diabetes mellitus was known to impair wound healing. However, the extend of delayed wound healing was not evaluate objectively in the diabetic rats. Therefore, we studied the extend of delayed wound healing(epithelialization and wound contracture) and histologic difference between diabetic and control rats. Twenty adult Sprague-Dawley rats(200-250 gm) were used as experimental animals(Diabetes: 10 rats, control: 10 rats). The wounds(2 x 2 cm, sized) were made on the back of the rats by excision through the panniculus carnosus. The areas of both wounds in relation to original wound areas (operative day) were serially measured at 0, 1,2, 3, 4, 5 weeks postoperatively. In addition, we performed histological examination of biopsy taken at 0, 1,2, 3, 4, 5weeks postoperatively. The difference in the mean area ratio between two groups was then compared using Kruskal Wallis test(SAS Program). Results were as follows: At postoperative 1 week, there was a significant difference(p < 0.05) in degree of epithelialization between the two groups, 1) After postoperative 2 weeks, there was a significant difference(p<0.05) in degree of wound contracture between the two groups. 2) In the diabetic group, the collagen fibers were smaller and poor organized than control group. Conclusion was that delay of epithelialization early and delay of wound contracture late in wound healing, were important roles in diabetic wound problem.