Q开关Nd:YAG 1064 nm激光照射对体外培养的PIG细胞黑素合成的影响

目的 探讨Q开关Nd:YAG 1064 nm激光照射对体外培养的人表皮黑素细胞系PIG细胞黑素合成的影响。方法 选择Medlite C6 Q开关Nd:YAG激光照射体外培养的PIG细胞，MTT法检测PIG细胞的活性，多巴氧化法检测酪氨酸酶活性的变化，荧光定量反转录（RT）-PCR和Westenr印迹分别检测酪氨酸酶相关蛋白（TRP）转录和蛋白表达水平。结果 ①在不影响细胞存活率的范围内，1 J/cm2照射后24 h时，PIG细胞酪氨酸酶活性（0.563 ± 0.014）与空白对照组（0.501 ± 0.019）比较轻度增加（P ＜ 0.05），酪氨酸酶与TRP-1 mRNA表达（分别为1.40 ± 0.11，1.28 ± 0.03）与空白对照组（1.0）比较明显上调（P ＜ 0.05），而TRP-2 mRNA表达（0.91 ± 0.17）并无明显变化（P ＞ 0.05），其蛋白水平的变化与转录水平相符。②在不影响细胞活性的范围内，3 J/cm2照射后24 h时，PIG细胞酪氨酸酶活性（0.343 ± 0.012）与空白对照组（0.501 ± 0.019）比较明显下降（P ＜ 0.05），酪氨酸酶、TRP-1和TRP-2的mRNA表达（分别为0.70 ± 0.02、0.73 ± 0.04、0.68 ± 0.04）和蛋白表达（分别为0.64 ± 0.05、0.86 ± 0.17、0.69 ± 0.11）与空白对照组（1.0）相比均不同程度的降低（P ＜ 0.05）。结论 Q开关Nd:YAG 1064 nm激光照射可以影响PIG细胞的黑素合成。在不影响细胞存活率的范围内，能量密度为1 J/cm2的Q开关 Nd:YAG 1064 nm激光照射能够刺激黑素合成，而3 J/cm2的照射对黑素合成有抑制作用。

Effects of irradiation with 1064-nm Q-switched Nd:YAG laser on melanogenesis in cultured PIG cells in vitro

Objective To study to the effect of 1064-nm Q-switched Nd:YAG laser irradiation on the melanogenesis in a human epidermal melanocyte line PIG. Methods Cultured PIG cells were irradiated with 1064-nm Q-switched Nd:YAG laser (Medlite C6) at different energy densities for 10 times. After additional culture for various durations, cell viability was detected by MT assay, tyrosinase activity by dopa oxidation assay, mRNA and protein expressions of tyrosinase, tyrosinase related protein (TRP)-1 and TRP-2 by real-time quantitative fluorescent RT-PCR and Westen blotting respectively, Results The irradiation with Q-switched Nd:YAG laser at energy densities from 1 to 3 J/cm2 had no obvious effect on the viability of PIG cells. After irradiation with Nd:YAG laser at 1 J/cm2, PIG cells showed a significant increase in the tyrosinase activity,mRNA expressions of tyrosinase and TRP-1 compared with unirradiated cells (0.563 ± 0.014 vs 0.501 ±0.019, 1.40±0.11 vs 1.0, 1.28 ± 0.03 vs 1.0, all P＜ 0.05), but both the mRNA (0.91 ± 0.17 vs 1.0, P＞0.05) and protein expressions of TRP-2 experienced no significant changes before and after the irradiation.However, a significant decrease was noted in PIG cells irradiated with Nd:YAG laser at 3 J/cm2 in tyrosinase activity, mRNA and protein expressions of tyrosinase (0.70 ± 0.02 vs 1.0, 0.64 ± 0.05 vs 1.0, both P ＜ 0.05),TRP-1 (0.73±0.04 vs l.0, 0.86±0.17 vs l.0, both P＜0.05) andTRP-2 (0.68±0.04 vs l.0,0.69±0.11vs 1.0, both P ＜0.05) in comparison with unirradiated PIG cells. Conclusions The 1064-nm Q-switched Nd:YAG laser irradiation may affect the melanogenesis in PIG cells. With no influence on cell viability, the 1064-nm Q-switched Nd:YAG laser at 1 J/cm2 could enhance melanogenesis, while that at 3 J/cm2 could suppress melanogenesis, in PIG cells.