Experimental Study On The Protective Effect Of LEKTI On The Skin Barrier Of BALB/c Mice Model Of Atopic Dermatitis

Objective: To investigate whether lymphoepithelial Kazal type-related inhibitor(LEKTI)encoded by serine protease inhibitor Kazal 5(SPINK5)has a protective effect on the skin barrier in 2,4-dinitrochlorobenzene(DNCB)induced atopic dermatitis(AD)mice.Methods:The recombinant adenovirus vector of mouse SPINK5 gene was constructed The AD model in BALB / c mice was induced by DNCB.The recombinant adenovirus vector containing SPINK5 gene was injected into the dorsal lesions of AD mice.The blank control group and dexamethasone(DEX)control group for local external use were set at the same time.,Skin lesion,pruritus score and dermatitis score were evaluated in AD mice.The pathological changes of mice in different treatment groups were observed under light microscope..Western Blot(WB)was used to detect the expression of LEKTI in the lesions of each group.Real Time PCR(RT-PCR)was used to detect the expression levels of LEKTI and skin barrier related protein Filaggrin(FLG)and its metabolism-related protease coding genes in each group:stratum corneum tryptic enzyme/kallikrein 5(SCTE/KLK5),stratum corneum chymotryptic enzyme/kallikrein 7(SCCE/KLK7),channel-activating serine protease1(CAP1),cysteine aspastic acid-specific protease 14(CASP14).Results: Compared with the model blank control group,mice treated with the SPINK5 recombinant adenoviral vector had significantly improved skin lesions,itching frequency,dermatitis score,epidermal thickness,infiltration of eosinophils and mast cells,increased the m RNA expression levels of SPINK5 and FLG and decreased the m RNA expression levels of KLK5,KLK7,CAP1 and CASP14(P<0.01).The number of scratching,epidermal thickness,the infiltration of eosinophil,the expression level of LEKTI and the m RNA expression level of SPINK5,FLG and KLK7 were significantly improved in the SPINK5 recombinant adenoviral vector treated after 17 days group compared with the 10 days group,the difference was statistically significant(p<0.01).Compared with DEX group,there was no statistical significance in the improvement of scratching times,epidermal thickness and the infiltration of eosinophil in mice treated with SPINK5 recombinant adenoviral vector after 17 days(P>0.05).There was no statistical significance in the improvement of skin lesions,dermatitis score,the infiltration of mast cell,the m RNA expression levels of CASP14,KLK5 and CAP1 between the SPINK5 recombinant adenoviral vector treated group and the DEX group(p > 0.05).Conclusion: LEKTI protein encoded by SPINK5 has obvious therapeutic effect on DNCB induced AD mice,and its mechanism is related to regulating the expression of FLG metabolism related enzymes,thus repairing the damaged skin barrier.