Sortilin Is Expressed in Cultured Human Keratinocytes and Is Regulated by Cutaneous Neuropeptides

Sortilin, a member of the family of Vps10p domain receptors, has been shown to be able to bind the precursor peptide of nerve growth factor (proNGF). ProNGF interacts with sortilin and the p75NTR receptor on the cell surface to form a molecular complex capable of activating an apoptotic cascade. Keratinocytes can secrete proNGF and they have p75NTR on their surface. The expression of sortilin in normal human keratinocytes has not yet been clearly shown. In this study, we show that keratinocytes express sortilin mRNA, and the presence of sortilin protein is shown in cultured keratinocytes and in normal human skin. We have also shown that the cutaneous neuropeptides substance P, calcitonin gene-related peptide, vasoactive intestinal polypeptide, and galanin are able to reduce the expression of sortilin mRNA and sortilin protein in cultured human keratinocytes. In addition, each of the analyzed neuropeptides has the ability to arrest the proNGF-induced apoptosis of human keratinocytes. These results suggest that all the participants in the NGF/proNGF pathway are present in the keratinocytes, and cutaneous neuropeptides can modulate their expressions and actions. The NGF/proNGF balance and its regulation by neuropeptides may have an important role in skin homeostasis

A tünetmentes pikkelysömörös bőr pathológiás elváltozásainak szerepe a betegség fenotípusának megjelenésében = The contribution of inherent abnormalities of non-lesional skin to disease phenotype in psoriasis

Az elvégzett kutatás alapkutatás, amely jelentős része klinikai jellegű, a pikkelysömör bőrbetegség pathomechanizmusának megértését célozza, ezáltal terápiás célpontokat jelöl ki a betegség gyógyításában. Közvetlen hasznosítás az elmúlt 4 évben nem történt, de ez nem is volt kitűzött cél, azonban a betegség kialakulásával kapcsolatban számos új adatot szolgáltattunk, melyeknek egy része szakmánk vezető folyóirataiban publikációra is került. Az utóbbi év eredményei új távlatokat nyitottak további kutatásaink célkitűzéseihez. A pályázatban vázolt munkáktól, csak annyiban tértünk el, amennyiben bizonyos eredmények más területen való hasznosítása értelemszerűen kívánkozott, valamint amennyiben kutatásunk eredményei új, fontosnak ítélhető megválaszolandó kérdéseket tettek fel. A munka eddig megjelent dolgozatai mellett 2 cikk közvetlen benyújtás előtt, kettő pedig az írás fázisában van. 1 hallgató a pályázat ideje alatt ebből a munkából írt és szerzett PhD fokozatot, jelenleg 2 hallgató PhD-ja készül részben az itt elvégzett munkákat is tartalmazva. | Within the project we carried out basic research toward the understanding of psoriasis pathomechanisms. Our research carries the possibility of new therapies in this common skin disease. We have made considerable progress in understanding key mechanisms of keratinocyte hyperproliferation, the major cutaneous characteristic of this skin disease. Our research work went according to the proposed plan, minor changes were made as required by experimental data. Some of the results have already been published in leading journals of our field, we are about to submit two papers and two is in the process of writing. One PhD student who worked on the project has successfully defended her thesis and two are presently working on their theses

In Vitro Dedifferentiation of Melanocytes from Adult Epidermis

In previous work we described a novel culture technique using a cholera toxin and PMA-free medium (Mel-mix) for obtaining pure melanocyte cultures from human adult epidermis. In Mel-mix medium the cultured melanocytes are bipolar, unpigmented and highly proliferative. Further characterization of the cultured melanocytes revealed the disappearance of c-Kit and TRP-1 and induction of nestin expression, indicating that melanocytes dedifferentiated in this in vitro culture. Cholera toxin and PMA were able to induce c-Kit and TRP-1 protein expressions in the cells, reversing dedifferentiation. TRP-1 mRNA expression was induced in dedifferentiated melanocytes by UV-B irradiated keratinocyte supernatants, however direct UV-B irradiation of the cells resulted in further decrease of TRP-1 mRNA expression. These dedifferentiated, easily accessible cultured melanocytes provide a good model for studying melanocyte differentiation and possibly transdifferentiation. Because melanocytes in Mel-mix medium can be cultured with human serum as the only supplement, this culture system is also suitable for autologous cell transplantation

Investigations on normal human adult epidermal melanoytes

For obtaining pure melanocyte cultures from human adult epidermis a novel culture technique using a cholera toxin and PMA-free medium (Mel-mix) was described by our group. In Mel-mix medium the cultured melanocytes become bipolar, unpigmented and highly proliferative. Further characterization of the cultured melanocytes revealed the disappearance of c-Kit and TRP-1 and induction of nestin expression, indicating that melanocytes dedifferentiated in this in vitro culture. Cholera toxin and PMA were able to induce c-Kit and TRP-1 protein expressions in the cells, reversing dedifferentiation. TRP-1 mRNA expression was induced in dedifferentiated melanocytes by UV-B irradiated keratinocyte supernatants, however direct UV-B irradiation of the cells resulted in further decrease of TRP-1 mRNA expression. Expressions of EGFR mRNA and protein and mitogenic effect of EGF on Mel-mix cultured melanocytes were proved. EGFR protein expression was more intensive in dedifferentiated melanocytes. These dedifferentiated, easily accessible cultured melanocytes provide a good model for studying melanocyte differentiation and possibly transdifferentiation. Because melanocytes in Mel-mix medium can be cultured with human serum as the only supplement, this culture system is also suitable for autologous cell transplantation