To investigate the differential expression of genes by 635nm LEDs irradiation in arachidonic acid-treated human gingival fibroblasts, cDNA microarray was carried out. Human gingival fibroblasts were primary cultured and arachidonic acid was treated to induce inflammation. 635nm of wave length was used for LEDs irradiation. The experimental group was categorized into four group ; control, only LEDs irradiation group, only arachidonic acid-treated group and arachidonic acid-treated with LEDs irradiation group. The expression of 8,078 genes were increased and the expression of 7,103 genes were decreased in only LEDs irradiation group. For arachidonic acid-treated with LEDs irradiation group, the expression of 6,815 genes were increased, while the expression of 8,031 genes were decreased comparing with only arachidonic acid-treated group. IL-13alpha2 receptor was the most expressed gene in LEDs irradiation group comparing with control, followed by MMP3. Genes which the most down regulated was BIRC3 in LEDs irradiation group. PLAB genes was the most up-regulated in arachidonic acid treated with LEDs irradation group, followed by ranked RARRES1. Considering the classification by cell function, genes associated with signal transduction were the most affected by LEDs irradiation, followed by the genes associated with nucleoside, nucleotide and nucleic acid metabolism. In arachidonic acid treated with LEDs irradiation, genes associated with signal transduction and protein metabolism were affected. Taken together, LEDs irradiation could affect various biological process and could identify many genes related to LEDs irradiation, which could be used for clinical application.

The process 0 1' wound healing needs the deposition of collagen and non-collagenous compounds, followed by the remodelling of extracellul ar matrix Recently, it has known that LEDs irradiation can help wound healing to accelerate the cell proliferation. But its mec hanism is not elucidated yot. The purpose of the present study is to observe the expression level of extracellular matrix by 635nm LEDs ir radiation. Human gingival fibroblasts were primary cultured, treated arac hidonic acid (때 and followed by LEDs irradiation. To observe the mRNA expression of extracellular matrix, cDNA mlcroarray was ca n‘ ied out 1n present study, 3 experimental groups were categorized into control, AA-treated group, and AA-treated with LEDs irradiation group. The differential expressions of MMP-1, -2, -3, - 10, - 11, -14, -16, - 17, -25 and TIMP-1, -2, -3. -4 were observed. Especially, mRNA expression of T1MP-3 was 10 fold decreased in arach idonic acid -treated with 635nm LEDs irradiation group. Finally, LEDs irradation can affect the expression level of MMPs and TIMPs, which lead to prolifer ation of gingival fibroblasts and result in would healing