Study On The Role And Mechanism Of Decorin In The Process Of Keloids

Objective:1.To investigate the expression of core protein glycan in keloids and its function in the formation of keloids.2.To explore the regulation mechanism of core proteoglycan on TGF-β1/Smad,PI3K/AKT and MAPK related signaling pathways during the development of keloid.Method:1.Eight cases of KD and normal tissues adjacent to KD were collected,then HE staining,immunohistochemical staining and Western blot method were executed to analyze the expression of Decorin(DCN)in KD tissues.The primary culture of keloid fibroblasts(KFs)and normal fibroblasts(NFs)were prepared with collagenase II,and the expression of DCN in KFs was detected by Western blot method.2.The knockdown of DCN in primary culture of KFs was achieved by means of siRNA method,after the knockdown was verified,the effects of DCN knockdown on the expression of ECM-related proteins,TGF-β1/Smad,PI3K/AKT and MAPK related signaling pathway proteins were detected through Western blot method.Result:1.The results of HE staining manifested that a clear dividing line existed between KD and the adjoining normal skin tissue.Collagen fibers on the KD side were compact and disarrayed,while the dermis of the normal skin side next to KD was thinner,collagen fibers arranged in an orderly manner,and spindle cells were sparse.Low expression of DCN was detected in KD tissues by immunohistochemcal staining.The expression of type I and type III collagen protein in KFs and extracellular fluid detected by Western blot method was more distinct than in NFs(P<0.01),and the expression of DCN in KFs detected by Western blot method was evidently more insignificant than that in NFs(P<0.01).2.DCN siRNA was able to stimulate the expression of ECM-related proteins in KFs and extracellular fluid,and promote the expression of p-Erk,p-Akt and p-P38 signaling pathway-related proteins in KFs(P<0.01).Conclusions:1.DCN protein is under-expressed in keloid tissue and keloid fibroblasts.2.DCN through PI3K/AKT and MAPK related signal pathways promoted the restrain of collagen protein Ⅰ and Ⅲ in KFs.