실크단백질의 식이 공급이 아토피 피부염 동물 모델 NC/Nga Mice 피부의 세라마이드 함량 및 관련인자 발현에 미치는 영향

Abstract

Ceramide rich intercellular lipid lamellae are thought to be particularly important in maintaining the structural integrity of epidermal barrier. Ceramide is synthesized de novo by serine palmitoyltransferase (SPT) phospholipid intermediates, serine and palmitic acid persist within the stratum corneum. The ceramide which is synthesized is degraded with fatty acid and sphingosine by degradative enzyme ceramidase. The depletion of ceramide in stratum corneum was reported in the atopic dermatitis. As an effort to search for the dietary source for improving the level of ceramide in epidermis, the dietary effects of various-typed silk protein were compared. Seventy male NC/Nga mice, an animal model of atopic dermatitis, were divided into seven groups: group CA as an atopic control with control diet, group S: 1% crude sericin diet, group F: 1% crude fibroin diet, group PS: peptide pattern of sericin (Mw 5000), group PF: peptide pattern of fibroin (Mw 1500), group AS: manufactured the same as amino acid profile of sericin and group AF: manufactured the same as amino acid profile of fibroin. Ten male BALB/c mice were served as group C (control group) control diet. All mice were fed on diet and water ad libitum for 10 weeks. Dry skin condition was established in group CA as ceram ide content was decreased. Despite a marked decrease of mRNA and prorein expression of SPT, enzyme de novosynthesis, ceramide content of group S was dramatically increased by inhibiting the mRNA and protein expression of degradative enzyme ceramidase. However, dietary supplementation of crude silk fibroin protein (group F) and in other groups that were supplemented with either amino acid or peptide type of sericin or fibroin did not increase the level of ceramide. Together, our data demonstrate that dietary supplementation of crude sericin is more effective at improving ceramide level in epidemis of NC/Nga mice.