title: Human sebum extract induces barrier disruption and cytokine expression in murine epidermis.
abstract: BACKGROUND
  Previous studies have shown that human sebum may play a role in barrier function but with much debate.
  
  
  OBJECTIVE
  To elucidate the effects of human sebum on skin barrier function.
  
  
  METHODS
  We used hairless mouse skin to study the functional and morphological alternation of epidermis after the application of human sebum.
  
  
  RESULTS
  The results showed a significant increase in transepidermal water loss and erythema value, and a decrease in skin hydration, accompanied by epidermal hyperplasia with parakeratosis following sebum application. Nile red staining together with electron microscopic examination confirmed the underlying mechanisms for sebum-induced barrier disruption are related directly to the interaction of sebum with the intracellular lipid lamellae of the SC, thereby leading to the increase in the fluidity of SC intracellular lipids as demonstrated by ATR-FTIR measurement. An inflammatory reaction characterized by an enhanced cytokine cascade, including up-regulation of TNF-α, IL-1α and IL-6, was also observed. On the other hand, there were insignificant expression of thymic stromal lymphopoietin and unchanged serum levels of IgE, suggesting non-immunogenic stimulation by sebum treatment.
  
  
  CONCLUSIONS
  It may be concluded that inflammation induced by excess amount of sebum is more likely an irritant contact dermatitis rather than an allergic one. Moreover, these findings implicated possible relationships between sebum, irritant contact dermatitis, and seborrheic dermatitis.
authors: Institute of Clinical Pharmacy and Pharmaceutical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors: Jiun-Wen
authors: JW
authors: Guo
authors: Department of Dermatology, National Chung Kung University Hospital, College of Medicine, National Chung Kung University, Tainan, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, National Chung Kung University, Tainan, Taiwan.
authors: Tzu-Kai
authors: TK
authors: Lin
authors: Department of Dermatology, Kaohsiung Medical University and Hospital, Kaohsiung, Taiwan.
authors: Chin-Han
authors: CH
authors: Wu
authors: Department of Dermatology, Kaohsiung Veterans General Hospital, Taiwan.
authors: Kai-Che
authors: KC
authors: Wei
authors: Department of Dermatology, Kaohsiung Medical University and Hospital, Kaohsiung, Taiwan; Department of Dermatology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors: Cheng-Che E
authors: CC
authors: Lan
authors: Department of Dermatology, National Chung Kung University Hospital, College of Medicine, National Chung Kung University, Tainan, Taiwan.
authors: Amy Chia-Ying
authors: AC
authors: Peng
authors: Institute of Clinical Pharmacy and Pharmaceutical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan. Electronic address: jctsai@mail.ncku.edu.tw.
authors: Jui-Chen
authors: JC
authors: Tsai
authors: Department of Dermatology, National Chung Kung University Hospital, College of Medicine, National Chung Kung University, Tainan, Taiwan; Department of Dermatology, College of Medicine, National Chung Kung University, Tainan, Taiwan. Electronic address: hmsheu@mail.ncku.edu.tw.
authors: Hamm-Ming
authors: HM
authors: Sheu
mesh_terms: D000328:Adult; D000818:Animals; D016207:Cytokines / Q000276:immunology / Q000378:metabolism*; D017453:Dermatitis, Irritant / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D004817:Epidermis / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D004890:Erythema / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D006801:Humans; D006965:Hyperplasia; D018836:Inflammation Mediators / Q000276:immunology / Q000378:metabolism*; D008297:Male; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000378:metabolism; D008812:Mice, Hairless; D010241:Parakeratosis / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D010539:Permeability; D012629:Sebum / Q000276:immunology / Q000378:metabolism*; D013997:Time Factors; D014870:Water Loss, Insensible
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D008563:Membrane Lipids
keywords: Cytokine expression; Dermatitis; Epidermal barrier function; Human sebum; Morphology