[Effect of Col I A1 antisense oligodeoxynucleotide on collagen synthesis in human hypertrophic scar transplanted nude mouse model].

UNLABELLED

Objective Col I A1 antisense oligodeoxynucleotide (ASODN) has inhibitory effect on collagen synthesis in cultured human hypertrophic scar fibroblasts. To investigate the effects of intralesional injection of Col I A1 ASODN on collagen synthesis in human hypertrophic scar transplanted nude mouse model.

METHODS

The animal model of human hypertrophic scar transplantation was established in the 60 BALB/c-nunu nude mice (specific pathogen free grade, weighing about 20 g, and aged 6-8 weeks) by transplanting hypertrophic scar without epidermis donated by the patients into the interscapular subcutaneous region on the back, with 1 piece each mouse. Fifty-eight succeed models mice were randomly divided into 3 groups in accordance with the contents of injection. In group A (n = 20): 5 microL Col I A1 ASODN (3 mmol/L), 3 microL liposome, and 92 microL Opti-MEM I; in group B (n = 20): 3 microL liposome and 97 microL Opti-MEM I; in group C (n = 18): only 100 microL Opti-MEM I. The injection was every day in the first 2 weeks and once every other day thereafter. The scar specimens were harvested at 2, 4, and 6 weeks after injection, respectively and the hardness of the scar tissue was measured. The collagens type I and III in the scar were observed under polarized light microscope after sirius red staining. The ultrastructures of the scar tissues were also observed under transmission electronic microscope (TEM). Additionally, the Col I A1 mRNAs expression was determined by RT-PCR and the concentrations of Col I A1 protein were measured with ELISA method.

RESULTS

Seventeen mice died after intralesional injection. Totally 40 specimens out of 41 mice were suitable for nucleic acid and protein study, including 14 in group A, 13 in group B, and 14 in group C. The hardness of scars showed no significant difference (P > 0.05) among 3 groups at 2 weeks after injection, whereas the hardness of scars in group A was significantly lower than those in groups B and C at 4 and 6 weeks (P < 0.05), and there was no significant difference between groups B and C (P > 0.05). The collagen staining showed the increase of collagen type III in all groups, especially in group A with a regular arrangement of collagen type I fibers. TEM observation indicated that there was degeneration of fibroblasts and better organization of collagen fibers in group A, and the structures of collagen fibers in all groups became orderly with time. The relative expressions of Col I A1 mRNA and the concentrations of Col I A1 protein at 2 and 4 weeks after injection were significant difference among 3 groups (P < 0.05), and they were significantly lower in group A than in groups B and C (P < 0.05) at 6 weeks after injection, but no significant difference was found between groups B and C (P > 0.05).

CONCLUSION

Intralesional injection of Col I A1 ASODN in the nude mice model with human hypertrophic scars can inhibit the expression of Col I A1 mRNA and collagen type I, which enhances the mature and softening of the scar tissue. In this process, liposome shows some assistant effect.