Effects of Low Level Laser on the Proliferation and Gene Expression of Fibroblasts and Immune Cells

저출력레이저조사가 섬유아세포와 면역세포의 증식 및 유전자발현에 미치는 영향

The growth and synthetic activities of fibroblasts are regulated by cytokines and growth factors derived from activated inflammatory cells. Stimulatory effect of low level laser (LLL) radiation on wound healing seems to be in part due to direct stimulatory action on cell proliferation and synthetic activities of fibroblasts. Also indirect stimulatory effect on the fibroblast function through inflammatory or immune cells is another possible mechanism of biostimulatory action of LLL. This study was performed to determine the growth rate of human gingival fibroblasts obtained biopsy and culture, fibroblast cell line, and immune cell line by using $[^3H]-$ thymidine incorporation test. And gene expression pattern was also analyzed by using the DNA probe such as Hsp70, IL-1$\beta$, MIP-1$\alpha$ and actin cDNA. Proliferation rate of gingival fibroblast was increased by LLL irradiation, but no more effect was added by LPS or IL-1$\beta$ pretreatment Enhanced Hsp70 gene expression was found from gingival fibroblasts and fibroblast cell line COS by LLL irradiation., which was not more increased by LPS or IL-1$\beta$ pretreatment. LLL-irradiated promyelcytic cell line HL-60 and macrophage cell line RAW264.7 showed significant stimulatory effect of proliferation rate when compared with respective control. However there were no changes in growth rate of other immune cell tested in this study, such as B cell line WR19n.l and 230, helper T cell line Jurkat and Hut78, cytolytic T cell line CTLL-r8. By LLL-irradiation Hsp70 gene expression was increased in RAW246.7 and HL-60, not in CTLL-R8. And IL-1$\beta$ and MIP-1$\alpha$ gene expression were induced only from LLL-irradiated RAW264.7. These results led us to presume that LLL radiation may affect to the immune cells, especially to macrophage, through which it might promote wound healing process.