The Expression And Significance Of The Pigment Epithelium-derived Factor (PEDF) In Pathological Scar

Objective: To investigate the expression and significance of the pigment epitheliumderived factor(PEDF)in pathological scar.Methods: During October 2017 to December 2019,64 cases of surgical tissue samples form 38 patients were obtained from Plastic Surgery Department,Affiliated Fujian Union Hospital.All clinical specimens were divided into four groups:11 cases of flat scar(Group A),12 cases of hypertrophic scar(Group B)and 15 cases of keloid(Group C).Meanwhile,there are 26 cases of normal skin(Group D)which were taken from the excess normal skin tissue around the scar.First of all,sections were stained by HE and Massson to determine the pathological diagnosis,verifying the correctness of the grouping.Then,The expressions of PEDF、VEGF、NF-κB、TGF-β1、α-SMA protein in four groups were examined with immunohistochemical polymer HRP method.Meanwhile,the m RNA expressions of these factors were detected with quantitative real-time PCR.Furthermore,the correlation between PEDF and MVD value(CD31 staining)、VEGF、NF-κB、TGF-β1、α-SMA expression were analyzed.Results: The results of HE staining and Masson staining showed that the dermal collagen of hypertrophic scar(group B)was thicker and more disorderly than normal skin(group D)and flat scar(group A).Some of them can be a nodular change,including high-density fibroblasts,immature vessels and randomly arranged collagen fibers.Among four groups,keloid(group C)had the thickest collagen fibers.Some of them even presented a gyrate change containing a large number of immature blood vessels and fibroblasts.The protein and m RNA expressions of PEDF in pathological scar were significantly lower than those in flat scar and normal skin(P<0.001),while the protein expressions of VEGF、NF-κB、TGF-β1、α-SMA and the m RNA expressions of VEGF、NF-κB、TGF-β1were much higher(P<0.001).The MVD,VEGF、NF-κB、TGF-β1 changes and the expressions of PEDF were found significantly negative correlated(P<0.001).Conclusions:PEDF may play a key role in the occurrence and development of pathological scar through inhibiting the excessive angiogenesis,hyperinflammatory response and abnormal fibrosis.