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Tight junction proteins in keratinocytes: localization and contribution to barrier function
Author(s) -
Yuki Takuo,
Haratake Akinori,
Koishikawa Hisa,
Morita Kazumasa,
Miyachi Yoshiki,
Inoue Shintaro
Publication year - 2007
Publication title -
experimental dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.108
H-Index - 96
eISSN - 1600-0625
pISSN - 0906-6705
DOI - 10.1111/j.1600-0625.2006.00539.x
Subject(s) - tight junction , occludin , claudin , barrier function , microbiology and biotechnology , stratum granulosum , chemistry , stratum corneum , permeability (electromagnetism) , epidermis (zoology) , biophysics , biology , biochemistry , anatomy , genetics , membrane
Recent research suggests that tight junctions (TJs) are located in the stratum granulosum, where they contribute to the barrier function of the epidermis. In this study, we investigated the formation of functional TJs in cultured normal human epidermal keratinocytes. We observed the development of permeability barrier function through the process of Ca 2+ ‐induced differentiation. Immunofluorescence analyses at 96 h after Ca 2+ ‐induced differentiation revealed concentrated portions of occludin, a TJ‐specific marker, arranged as continuous lines circumscribing individual flattened suprabasal cells in areas with high concentrations of claudin‐1 and ‐4. Transient Ca 2+ depletion reversibly disrupted the continuous network of TJ proteins and the permeability barrier. We also found that the addition of ochratoxin A weakened the permeability barrier and the expression of claudin‐4. Our findings suggest that TJ proteins contribute to the permeability barrier in epidermal keratinocytes.