Inhibitory effect of small proteoglycan, decorin, on hypertrophic scars in rabbit ears

Abstract

Objective To observe the inhibitory effect of decorin on hypertrophic scar in rabbit ears. Methods Full-thickness excisional wounds, 8 mm in diameter, were made over the ventral side of ears in 8 adult New Zealand white rabbits, and 48 hypertrophic scars in total. Then the rabbits were divided into two groups: group A, experimental group (decorin, 10 mg/L); group B, control group (physiological saline). At the 20th and 30th day after operation, the hypertrophic scars were injected with decorin (group A) and saline (group B) intralesionally. Samples were harvested 20 days after the last injection (50th day) for measurement of scar elevation index (SEI). The expression of type Ⅰ collagen protein and type Ⅰ pro-collagen mRNA was assessed by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR) respectively. Results Compared with group B, the scars appeared to be flatter,softer, and lighter in color in group A. The SEI in group A and group B was 2. 8970 ±0. 2066 and 3. 5210 ±0. 1960 respectively. The expression of type Ⅰ collagen protein and type Ⅰ pro-collagen mRNA in group A was 0. 221 20 ±0. 027 06 and 0. 372 50 ±0.026 78 respectively, and that in group B was 0. 336 90 ±0.030 74 and 0.645 60 ±0.029 94 respectively ( all P ＜ 0.05). Conclusion Decorin can inhibit the proliferation process of hypertrophic scar in rabbit ears and remarkably decrease the degree of fibrosis in the scar. Key words: Hypertrophic scar; Proteoglycan