脉冲掺钕钇铝石榴石激光对增生性瘢痕成纤维细胞胶原合成的影响

摘要

目的　探讨脉冲掺钕钇铝石榴石(Nd:YAG)激光对体外培养瘢痕成纤维细胞胶原合成的选择性抑制作用。方法　以不同能量密度（500 J/cm2、1 000 J/cm2、1 500 J/cm2和2 000 J/cm2）Nd:YAG激光（波长1 064 nm，脉宽150 μs）照射体外培养增生性瘢痕和正常皮肤成纤维细胞，照射后24 h分别用3H-脯氨酸掺入法和斑点杂交法检测成纤维细胞胶原合成和I型前胶原基因表达。 结果　体外培养增生性瘢痕成纤维细胞胶原合成高于正常皮肤，约为正常皮肤的2倍，I型前胶原基因表达亦明显高于正常皮肤，约为正常皮肤的3倍；以500 J/cm2激光照射，增生性瘢痕与正常皮肤成纤维细胞胶原合成、I型前胶原mRNA水平均无变化，以1 500 J/cm2、2 000 J/cm2能量密度激光照射，增生性瘢痕成纤维细胞胶原合成、I型前胶原mRNA水平都显著降低（P<0.001，P<0.001）；正常皮肤成纤维细胞胶原合成、I型前胶原mRNA水平在1 500 J/cm2激光照射后降低（P<0.001，P<0.01），2 000 J/cm2照射后亦显著降低（P<0.001，P<0.05）；以1 000 J/cm2照射，增生性瘢痕成纤维细胞胶原合成与I型前胶原基因表达显著下降（P<0.001），而正常皮肤成纤维细胞胶原合成和I型前胶原基因表达却无明显变化。结论　1 000 J/cm2脉冲Nd:YAG激光照射能选择性抑制增生性瘢痕成纤维细胞胶原合成和I型前胶原基因表达。%Objective　In order to explore the selectively inhibitory effects of pulsed Nd:YAG laser irradiation on collagen production of scar fibroblasts in vitro. Methods　Cultured fibroblasts derived from hypertrophic scars (HS) and normal human skin were irradiated with a pulsed Nd:YAG laser(wavelength 1 064 nm, pulse width 150(μs) at various energy density levels (500 J/cm2, 1 000 J/cm2, 1 500 J/cm2 and 2 000 J/cm2). At 24 hours after laser irradiation, collagen production of fibroblasts was measured by the incorporation of ［3H］proline. The expression of proα1(I) procollagen mRNA was investigated by blot hybridization techniques. Results　Collagen production of HS fibroblasts was significantly increased, as 2 times as that of normal skin fibroblasts. Type I procollagen mRNA level in HS fibroblasts was markedly elevated, as 3 times as that in normal skin fibroblasts. Collagen synthesis and type I procollagen mRNA level in HS fibroblasts remained unchanged at energy level of 500 J/cm2, and were significantly decreased at energy density of 1 500 and 2 000 J/cm2 (P<0.001,P<0.001). Collagen synthesis and type I procollagen mRNA level in normal dermal fibroblasts were markedly decreased at energy density of 1 500 J/cm2 (P<0.001,P<0.05), and were also reduced at energy denstity of 2 000 J/cm2 (P<0.001,P<0.01). Collagen production and type I procollagen mRNA level in HS fibroblasts was markedly reduced at energy density of 1 000 J/cm2 (P<0.001), the dose at which did not affect collagen synthesis and type I procollagen mRNA level in normal dermal fibroblasts. Conclusion　Pulsed Nd: YAG laser at energy density of 1 000 J/cm2 can selectively suppress collagen synthesis and type I procollagen mRNA level of HS fibroblasts.