The Study Of Expression Of ERK/MAPK Signaling Pathway In The Process Of Oral Ulcer Healing Promoted By The Switched Nd:YAG Laser

Objective:To investigate the expression of ERK/MAPK signaling pathway in the process of oral ulcer healing promoted by the switched Nd:YAG laser.Methods:Forty male SD rats were selected,and ten of them was the control group,oral ulcer models were established in the other 30 SD rats through immune method combine with trauma method.Ten of which as the ulcer group and collected the tissue,ten of which were treated by Triamcinolone Acetonide Dental Paste as the drug group,ten of which were treated by switched Nd:YAG laser as the laser group.After two days,the tissues of the drug group and the laser group were collected.Then,tissue of each group were detected by HE staining,the expressions of MMP-2,MMP-9,TIMP-1 and type Ⅳcollagen were examined by immunohistochemistry,and the expressions of EMMPRIN,ERK1/2 and p-ERK1/2 in each group were detected by Western-blot.Results:1.The result of HE staining: there are no epithelial defects in control group;In the ulcer group,tissue epithelium defects,the fibrous tissue edema and collagen fiber arrangement disorder were observed,and inflammatory cells can be seen in the submucosa..In the laser group,the epithelium basically healed,the epithelial nail process was slightly prolonged,and a small amount of inflammatory cell infiltration in submucosa.2.The result of Immunohistochemical : The expressions of MMP-2 and MMP-9 in ulcer group were significantly higher than those in control group(P<0.001 and P<0.01),but the expressions of MMP-2 and MMP-9 in laser group were significantly lower than those in ulcer group(P<0.001 and P<0.05).The expressions of TIMP-1 and type Ⅳcollagen in ulcer group were lower than those in control group(P<0.05),but the two indicators in laser group were higher than those in ulcer group(P<0.01).3.The result of Western-blot: The expressions of EMMPRIN and ERK1/2 in ulcer group was higher than those in control group(P<0.01),and the expressions of EMMPRIN and ERK1/2 in laser group were lower than those in ulcer group(P<0.05).There were no significant differences in the expression of p-ERK1/2 among control group,ulcer group,drug group and laser group.Conclusion:1.In the process of promoted oral ulcer by the switched Nd:YAG laser,the expression of EMMPRIN was inhibited,and the expression of downstream molecules MMP-2 and MMP-9 are further inhibited,while the expression of TIMP-1 was promoted,and then the expression of type Ⅳ collagen was promoted.2.The promotion of oral ulcer healing by the switched Nd:YAG laser may be related to ERK/MAPK signaling pathway.