BACKGROUND AND OBJECTIVES The aim of this study is to determine whether the hyperproliferative and hyperkeratotic characters of cholesteatoma are associated with differentiation of keratinocytes in cholesteatoma by examining the localization of marker proteins, such as involucrin, filaggrin, and cytokeratins. MATERIALS AND METHODS Immunohistochemical study was carried out in 30 cholesteatoma ...

The defined, serum-free media used in the cultivation of skin equivalents are liable to inter-laboratory variations, require the preparation of multiple additives, and are potentially difficult to replicate. In this study, we assessed the use of standardized, serum-free and bovine pituitary extract-free keratinocyte culture media in the development of a human skin equivalent. After culture at t...

BACKGROUND Through differentiation processes, keratinocytes provide a physical barrier to our bodies and control skin features such as moisturization, wrinkles and pigmentation. Keratinocyte differentiation is disturbed in several skin diseases such as psoriasis and atopic dermatitis. OBJECTIVE The aim of this study is to evaluate the keratinocyte differentiation-enhancing effect of rose abso...

Erythrokeratoderma variabilis, characterized by migrating erythema and fixed keratotic plaques, is a rare congenital disorder which has recently been connected with connexin (Cx)30.3 or Cx31 gene mutations. We present a 9-month-old Japanese girl who exhibited the typical clinical features of the disease, but carried no Cx30.3 or Cx31 gene mutations. Histopathologically, regular acanthosis with ...

Our previous study shows that inhibiting activator protein one (AP1) transcription factor function in murine epidermis, using dominant-negative c-jun (TAM67), increases cell proliferation and delays differentiation. To understand the mechanism of action, we compare TAM67 impact in mouse epidermis and in cultured normal human keratinocytes. We show that TAM67 localizes in the nucleus where it fo...

Skin photoaging due to UV irradiation is a degenerative process that appears more and more as a growing concern. Lipids, including oxysterols, are involved in degenerative processes; as skin cells contain various lipids, the aim of our study was to evaluate first, changes in keratinocyte lipid levels induced by UV exposure and second, cellular effects of oxysterols in cell morphology and severa...

The roles of autoimmune regulator (Aire) in the expression of the diverse arrays of tissue-restricted antigen (TRA) genes from thymic epithelial cells in the medulla (medullary thymic epithelial cells [mTECs]) and in organization of the thymic microenvironment are enigmatic. We approached this issue by creating a mouse strain in which the coding sequence of green fluorescent protein (GFP) was i...

PURPOSE To develop a reproducible procedure for the long-term culture of corneal epithelial cells from a single mouse cornea. METHODS Corneal limbal explants of C57BL6/J mice were cultured in serum-free, low-Ca(2+) medium supplemented with EGF and cholera toxin. Epithelial cells were subcultured at a 1:3 split until passage (P)4 and at lower densities after P4. Colony-forming efficiency, popu...

In normal epidermis, beta1 integrin expression is confined to the basal layer, whereas in hyperproliferative epidermis, integrins are also expressed in the suprabasal layers. Transgenic mice in which integrins are expressed suprabasally via the involucrin promoter have a sporadic psoriatic phenotype; however, the mechanism by which integrins contribute to the pathogenesis of psoriasis is unknow...

Late in terminal differentiation, human epidermal keratinocytes form an insoluble protein envelope on the cytoplasmic side of the plasma membrane. Involucrin, a soluble protein precursor of the envelope, is synthesized at an earlier stage of differentiation, both in the natural epithelium and in cultured keratinocytes. Because keratinocytes are known to enlarge during differentiation, we looked...