Objective: To mimic contact pattern between decorin and TGF-beta1, in vivo, and investigate the antagonistic effect of recombinant human decorin on TGF-beta1 stimulation of hypertrophic scar fibroblasts in collagen lattices.
Methods: Fibroblasts populated collagen lattices (FPCL) model was adopted in the study, and they were divided into control group, decorin group [2mg/L recombinant human decorin (rh-decorin) was administered to FPCL], TGF-beta1 group (5 microg/LTGF-beta1 was administered to the culture medium), and TGF-beta1 + decorin group (2mg/L rh-decorin was administered to FPCL, then culture medium containing 5 microg/L TGF-beta1 was added into FPCL). Changes in PAI-1 and alpha-SMA protein expression in scar fibroblasts in collagen lattices were detected with Western blotting at 12 post-administration hour (PAH), 24 PAH, 48 PAH, and 72 PAH, and expressions of PAI-1 and alpha-SMA mRNA were concomitantly examined by RT-PCR.
Results: The contraction of FPCL at each time-point in control group was obviously attenuated compared with that in decorin group, but it was significantly intensified compared with that in TGF-beta1 group. The expression of PAI-1 and alpha-SMA mRNA and protein in TGF-beta1 group (3482 +/- 211, 4320 +/- 272, 0.89 +/- 0.15, 0.56 +/- 0. 11) were markedly increased than those in control group (1764 +/- 147, 1699 +/- 146, 0.29 +/- 0.06, 0.21 +/- 0.06, P < 0.01), while no obvious difference of them was found between control and other two groups.
Conclusion: Stimulation of scar fibroblasts by TGF-beta1, can be suppressed when rh-decorin is blended into collagen lattices, indicating that decorin is effective in neutralizing TGF-beta1 in vitro. The pathogenesis of hypertrophic scar might be related to up-regulation of TGF-beta1 with the lack of decorin after cutaneous injury.