Browsing by Subject "Keratinocyte"

Now showing 1 - 4 of 4
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    Antinuclear antibody-keratinocyte interactions in photosensitive cutaneous lupus erythematosus
    (Murcia : F. Hernández, 1999) Furukawa, F.
    Autoimmune diseases are characterized by various circulating autoantibodies, especially antinuclear antibodies (ANA). It has been a long-standing issue as to whether andlor how ANA interact with epidermal cells to produce skin lesions. Of these ANA, the anti-SS-AIR0 antibody is the most closely associated with photosensitivity in patients with systemic lupus erythematosus (SLE) and its subgroups, including subacute cutaneous lupus erythematosus (SCLE) and neonatal lupus erythematosus (NLE). SS-A/Ro antigens are present in the nucleus and cytoplasm, and interestingly, ultraviolet B (UVB) light translocates these antigens to the surface of the cultured keratinocytes. Thus, anti-SS-AIR0 antibodies in the sera can bind to the relevant antigens expressed on the UVB-irradiated keratinocyte surface, and have been speculated to be an important inducer of antibody-dependent keratinocyte damage. This interaction between the anti-SS-A/Ro antibodies and UVBirradiated keratinocytes may induce the skin lesions through a cytotoxic mechanism. This review will focus on the involvement of antibody-dependent cellular cytotoxicity in the pathogenesis of the skin lesions observed in photosensitive cutaneous lupus erythernatosus.
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    Expression of acyl-CoA synthetase 5 in human epidermis
    (Murcia : F. Hernández, 2008) Gaisa, N.T.; Köster, J.; Reinartz, A.; Ertmer, K.; Ehling, J.; Raupach, K.; Perez-Bouza, A.; Knüchel, R.; Gassler, N.
    The human epidermis is characterized by a constant renewal of keratinocytes embedded in a matrix enriched with lipids. Numerous proteins involved in lipid metabolism are found in human epidermis, especially in keratinocytes. Long-chain acyl-CoA derivatives, which are catalyzed by human ACSL5, are important metabolites in several biochemical pathways, including ceramide de novo synthesis. The aim of the present study was to investigate expression of acyl-CoA synthetase isoform 5 (ACSL5) in human epidermis by an in situ, as well as a molecular approach. We show that ACSL5 mRNA and protein are found in human epidermis, as well as in non-differentiated and differentiated HaCaT cells. Keratinocytes of stratum spinosum are the main source for ACSL5 expression in both meshed facial or abdominal skin and ridged skin of upper or lower extremities including TUNEL-positive cells in upper cellular layers. Single keratinocytes of chronic solar-exposed meshed facial epidermis occasionally display a stronger ACSL5 immunostaining. In conclusion, our study indicates that epidermal ACSL5 expression might be involved in differentiation and the stress response of keratinocytes.
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    Presence of MUC1 in the epidermal thickening of psoriatic plaques
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2015) Arciniegas, Enrique; Carrillo, Luz Marina; Páez, Erika; Rojas, Héctor; Ramírez, Richard; Reales, Eysi; Chopite, Marina
    Mucin 1 (MUC1) is a transmembrane glycoprotein that protects epithelial cells from injury caused by external stimuli. In addition to this role, MUC1 is involved in cell-cell adhesion, proliferation, motility, invasion and survival. In epithelial cells, MUC1 expression is regulated by binding of TNFα to TNFR1 and activation of the NFκB pathway. In human skin, MUC1 is not expressed in normal epidermis but rather in pre-malignant and malignant conditions. Nevertheless, the expression of MUC1 and its implication in psoriasis vulgaris has not been considered. Here, we show that MUC1 was present in the epidermis of psoriatic plaques observed in 11 biopsies from patients diagnosed with psoriasis vulgaris which were compared with 5 normal human skin. Interestingly, MUC1 in addition to being localized at the apical surface of some suprabasal keratinocytes, was also localized over the entire cell surface of some of these cells and some basal keratinocytes. Conversely, no MUC1 immunoreactivity was detected in the epidermis of normal skin. Additionally, we demonstrated that activated TNFR1, cSrc, IKKα/β and p50/p65 were present in the epidermal thickening. This study demonstrates the presence of MUC1 in psoriatic plaque and suggests a possible role for MUC1 during the motility, migration and survival of human keratinocytes, where activated TNFR1, c-Src and NFκB seem to be required.
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    Preservation of human skin structure and function in organ culture
    (Murcia : F. Hernández, 1998) Varani, J.
    Human keratinocytes can be maintained in monolayer culture under serum-free conditions for an extended period of time. Under low ca2+ conditions (e.g., 0.05-0.15 mM), an undifferentiated state is maintained and the cells proliferate optimally. When the ca2+ concentration is raised to approximately 1.0 mM, differentiation occurs and growth slows. Human dermal fibroblasts can also be maintained in monolayer culture under serum-free conditions, but in contrast to keratinocytes, a physiological level of extracellular ca2+ (above approximately 1.0 mM) is required. A variety of growth factors stimulate roliferation of both cell types but do not replace the CaP+ requirement of the fibroblast population. All-trans retinoic acid also promotes proliferation of both cell types and, most interestingly, replaces the requirement for a physiological level of ca2+ in the fibroblast cultures. Human skin can be maintained in organ culture for an extended period of time under serum-free conditions. Conditions optimized for fibroblast proliferation (either physiological ca2+ or all-trans retinoic acid) are required. In the presence of culture conditions optimized for the epithelial cell component, both the epidermis and dermis rapidly lyse. These data suggest that the fibroblast is the critical component in maintaining homeostasis of skin, and that maintenance of the epidermis as well as the dermis depends on the viability and functioning of these cells.