Low-Energy Helium-Neon Laser Irradiation Stimulates Interleukin-1α and Interleukin-8 Release from Cultured Human Keratinocytes

Abstract

Clinical observations have suggested that low-energy lasers might promote wound healing. Evidence suggests that He-Ne laser irradiation induces an increase in the rate of keratinocyte migration and proliferation as compared with nonirradiated controls in vitro. This study sought to determine whether He-Ne laser could induce cytokine production in cultured keratinocytes. The results revealed (i) a significant increase in interleukin-1α and interleukin-8 production and their respective mRNA expression in He-Ne laser–treated groups as compared with nonirradiated controls, and (ii) under 1.5 joules/cm2 irradiation, this stimulating effect of He-Ne laser treatment is concentration-dependent. Because interleukin-1α induces keratinocyte migration, this finding may partially explain the stimulatory effects on the motility of keratinocytes. As both interleukin-1α and inteleukin-8 provoke proliferation of keratinocyes, it is not unreasonable to propose that these tow cytokines play a profound role in the enhancement of keratinocyte proliferation as a result of He-Ne laser irradiation. Our findings provide further evidence of enhanced wound healing at the cellular and molecular level as result of the He-Ne laser