[Addendum to the contribution by Rupec, RA, et al.: Erythema palmare hereditarium].
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Adult↗
Biomedical subjects
R Rupec
Publications and source records attributed to R Rupec.
Granulocyte/macrophage-colony-stimulating factor induces the migration of human epidermal Langerhans cells in vitro.
In the present study, we investigated the in vitro migratory activity of human epidermal Langerhans cells (LC). Freshly isolated LC exhibit very low spontaneous migration. In contrast, a strong migration is recorded 6 h after the isolation. This migration is due to the presence of GM-CSF released by surrounding keratinocytes in vitro. Picomolar concentrations of GM-CSF promote the migration of LC, but nanomolar concentrations are inhibitory. Checker-board experiments indicate that GM-CSF acts as a chemokinetic mediator for LC, Bulk cultured LC exhibit a significant decrease of their spontaneous migration but retain the capacity to respond to GM-CSF only at nanomolar concentrations. In contrast, LC cultured in the presence of picomolar concentrations of exogenous GM-CSF exhibit a spontaneous migratory activity comparable to that of 6 h rested LC but do not respond to GM-CSF. These results suggest that GM-CSF represents an essential factor triggering the egress of LC from their epidermal environment.
Cell Movement↗
[Malignant blue nevus].
A 35-year-old male patient suffering from a malignant blue naevus is presented. An uncommon melanocytic naevus and malignant melanoma were considered in the differential diagnosis. The final diagnosis was established by histological examination. Immunohistochemical studies showed a strongly positive reaction of the tumour cells for vimentin and S-100 protein. In addition, tumour cells reacted with the antibody HMB-45.
Adult↗
Langerhans cells of the human skin possess high-affinity 12(S)-hydroxyeicosa tetraenoic acid receptors.
The arachidonic acid metabolite 12-hydroxyeicosatetraenoic acid (12-HETE) is the main eicosanoid formed by epidermal cells and is assumed to play an important role in skin physiology and pathophysiology. Our aim was to find out whether epidermal Langerhans cells possess specific receptors for 12-HETE which would mediate the effects of this eicosanoid in their skin microenvironment. By radioligand binding studies on isolated human Langerhans cells, we could identify specific binding sites for 12(S)-HETE. The analysis of binding data revealed a single class of binding sites with a Kd of 3.32 +/- 0.45 nM and a Bmax of 691,000 +/- 58,000 receptors per cell. The binding was saturable, readily reversible, and specific for 12(S)-HETE. The receptor is likely to mediate the potent chemotactic response of human Langerhans cells towards 12(S)-HETE, which we previously described. Our results strongly suggest that extremely low concentrations of 12-HETE which is formed by epidermal keratinocytes may dramatically influence the biology of Langerhans cells by receptor-mediated effects.
12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗