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1.
J Eur Acad Dermatol Venereol ; 36(11): 2008-2015, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35842932

ABSTRACT

BACKGROUND: Patients diagnosed with cancer frequently search the Internet for health information. Yet, the quality of CTCL online information has not been investigated so far. OBJECTIVES: The aim of this study was to identify and assess the most visible websites on CTCL. METHODS: An Internet search on the top three search engines Google, Yahoo and Bing was performed for the terms 'cutaneous T-cell-lymphoma', 'mycosis fungoides' and 'Sézary syndrome'. After selecting the most frequented websites suitable for patients' information, we investigated content quality, readability and popularity. Eighty-nine websites were evaluated for HONcode quality certification, social media popularity, Alexa popularity rank, topicality and readability levels. Furthermore, the websites' content on 13 major topics according to guidelines on CTCL was assessed. RESULTS: Twenty-three (25.8%) websites were HONcode certified. Evaluated websites were difficult to read requiring at least 9 years of US school education to properly understand the information. More than half of all websites (57.3%) have not been updated for three or more years (or did not contain any update information). We found greatly varying quality and popularity of online patient information. Out of 1157 topics (equivalent to 13 different topics on 89 websites), 59.44% were mentioned on the websites. Of these, 40% contained incorrect or incomplete information. Publicly provided websites presented the different topics more thoroughly. We could further show that HONcode certified websites received better quality and readability scores. CONCLUSIONS: We found major shortcomings regarding readability, completeness and reliability of websites on CTCL. Nevertheless, highly selected websites on CTCL can serve as a valuable and reliable source of patient information. As a consequence, oncologists have an obligation to be aware of and guide their patients to available websites that contain reliable and appropriate information.


Subject(s)
Consumer Health Information , Lymphoma, T-Cell, Cutaneous , Social Media , Comprehension , Humans , Internet , Reproducibility of Results
2.
J Eur Acad Dermatol Venereol ; 36(10): 1766-1773, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35570468

ABSTRACT

BACKGROUND: SARS-CoV-2 has massively changed the care situation in hospitals worldwide. Although tumour care should not be affected, initial reports from European countries were suggestive for a decrease in skin cancer during the first pandemic wave and only limited data are available thereafter. OBJECTIVES: The aim of this study was to investigate skin cancer cases and surgeries in a nationwide inpatient dataset in Germany. METHODS: Comparative analyses were performed in a prepandemic (18 March 2019 until 17 March 2020) and a pandemic cohort (18 March 2020 until 17 March 2021). Cases were identified and analysed using the WHO international classification of diseases codes (ICDs) and process key codes (OPSs). RESULTS: Comparing the first year of the pandemic with the same period 1 year before, a persistent decrease of 14% in skin cancer cases (n = 19 063) was observed. The largest decrease of 24% was seen in non-invasive in situ tumours (n = 1665), followed by non-melanoma skin cancer (NMSC) with a decrease of 16% (n = 15 310) and malignant melanoma (MM) with a reduction of 7% (n = 2088). Subgroup analysis showed significant differences in the distribution of sex, age, hospital carrier type and hospital volume. There was a decrease of 17% in surgical procedures (n = 22 548), which was more pronounced in minor surgical procedures with a decrease of 24.6% compared to extended skin surgery including micrographic surgery with a decrease of 15.9%. CONCLUSIONS: Hospital admissions and surgical procedures decreased persistently since the beginning of the pandemic in Germany for skin cancer patients. The higher decrease in NMSC cases compared to MM might reflect a prioritization effect. Further evidence from tumour registries is needed to investigate the consequences of the therapy delay and identify the upcoming challenges in skin cancer care.


Subject(s)
COVID-19 , Melanoma , Skin Neoplasms , COVID-19/epidemiology , Germany/epidemiology , Humans , Inpatients , Melanoma/epidemiology , Melanoma/pathology , Melanoma/therapy , Pandemics , SARS-CoV-2 , Skin Neoplasms/epidemiology , Skin Neoplasms/therapy , Melanoma, Cutaneous Malignant
3.
J Eur Acad Dermatol Venereol ; 34(2): 285-292, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31465594

ABSTRACT

BACKGROUND: In melanoma, preclinical data suggest a possible role of polyunsaturated fatty acids inhibiting cell growth. A new target molecule for free fatty acids, the G protein-coupled receptor GPR40, was identified in melanoma cells. OBJECTIVES: The aim of this study was to investigate GPR40 expression in human melanocytic tissues and to evaluate its potential as a prognostic marker. METHODS AND RESULTS: A total of 114 tissue sections of naevi, primary melanoma and melanoma metastasis were immunohistochemically stained with anti-GPR40. The staining was evaluated, using the immunoreactivity scoring system. Compared to naevi, primary melanoma and melanoma metastasis showed significantly higher levels of GPR40 (P < 0.05). In primary melanoma, GPR40 expression positively correlated with tumour thickness (P = 0.044) and AJCC level (P = 0.017) and in melanoma metastasis with AJCC level (P = 0.035). Primary melanoma patients with high levels of GPR40 had a significantly poorer overall survival (P = 0.004) and shorter disease-free survival (0.040). CONCLUSION: The present study identified GPR40 as a novel target molecule in melanoma. First evidence for a potential role of the receptor in tumour progression and metastases was found, and it could be demonstrated that GPR40 expression is negatively correlated with patient's survival.


Subject(s)
Melanoma/metabolism , Receptors, G-Protein-Coupled/metabolism , Skin Neoplasms/metabolism , Biomarkers, Tumor/metabolism , Female , Humans , Male , Melanoma/pathology , Middle Aged , Neoplasm Staging , Skin Neoplasms/pathology , Survival Analysis
4.
Eur Rev Med Pharmacol Sci ; 23(23): 10564-10574, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31841214

ABSTRACT

OBJECTIVE: Although the natural compound curcumin exerts antitumor properties in vitro, its clinical application is hampered due to rapid metabolism. Light exposure following curcumin application has been demonstrated to improve curcumin's bioavailability. Therefore, this investigation was directed towards evaluating whether light exposure in addition to curcumin application enhances curcumin's efficacy against bladder cancer cell adhesion and migration. MATERIALS AND METHODS: RT112, UMUC3, and TCCSUP cells were incubated with low curcumin concentrations (0.1-0.4 µg/ml) and then exposed to 1.65 J/cm2 visible light for 5 min. Controls remained untreated or were treated with curcumin or light alone. Cell adhesion to Human umbilical vein endothelial cells (HUVECs), to immobilized collagen or fibronectin and chemotactic behavior, integrin α and ß receptor expression with functional relevance, as well as focal adhesion kinase (total and phosphorylated FAK) were evaluated. RESULTS: Curcumin plus light, but neither curcumin nor light alone, significantly altered tumor cell adhesion and suppressed chemotaxis. Integrin α and ß subtypes were dissimilarly modified, depending on the cell line. Suppression of pFAK was noted in RT112 and UMUC3, but not in TCCSUP cells. The integrins α3, α5, and ß1 were involved in curcumin's regulation of adhesion and migration. Blocking studies revealed α3, α5, and ß1 to be associated with TCCSUP adhesion and migration, whereas α5 and ß1, but not α3 contributed to UMUC3 adhesion and migration. Integrin α5 and ß1 controlled RT112 chemotaxis as well, but only α5 was involved in the RT112 adhesion process. CONCLUSIONS: Combining curcumin with light exposure enhances curcumin's anti-tumor potential.


Subject(s)
Antineoplastic Agents/pharmacology , Curcumin/pharmacology , Light , Photochemotherapy/methods , Urinary Bladder Neoplasms/drug therapy , Antineoplastic Agents/therapeutic use , Biological Availability , Cell Adhesion/drug effects , Cell Adhesion/radiation effects , Cell Culture Techniques , Cell Line, Tumor , Chemotaxis/drug effects , Chemotaxis/radiation effects , Curcumin/therapeutic use , Human Umbilical Vein Endothelial Cells , Humans , Urinary Bladder Neoplasms/pathology
5.
J Eur Acad Dermatol Venereol ; 32(11): 2010-2019, 2018 Nov.
Article in English | MEDLINE | ID: mdl-29705993

ABSTRACT

BACKGROUND: Adipose-derived stem cells (ASC) are known to transdifferentiate into a wide range of different cell species in vitro including along the epidermal lineage. This property makes them a promising tool for regenerative medicine to restore the epidermal barrier. OBJECTIVE: This study is dedicated to identify in vitro conditions enabling transdifferentiation to a keratinocyte-like phenotype. In particular, the impact of different culture conditions (media compositions, 2D, 3D cultures) and extracellular matrix (ECM) molecules was evaluated. METHODS: Adipose-derived stem cells derived from subcutaneous abdominal fat were characterized by stemness-associated markers and subjected to different media. Epithelial differentiation in 2D cultures was monitored by pan-cytokeratin expression using flow cytometry and immunocytochemistry. To evaluate the impact of different ECM molecules on epidermal stratification, 3D cultures were produced, lifted to the air-liquid interface (ALI) and examined by histological analysis and quantitative real-time RT-PCR. RESULTS: We identified a medium composition containing retinoic acid, hydrocortisone, ascorbic acid and BMP-4 enabling maximum pan-cytokeratin expression in 2D cultures. Moreover, adhesion to type IV collagen further promotes the pan-cytokeratin expression. When cultures were lifted to the ALI, significant stratification was observed, particularly in supports coated with type IV collagen or fibronectin. Moreover, epidermal differentiation markers (involucrin, cytokeratin 1 and 14) become induced. CONCLUSION: Conditions with hampered wound healing such as non-healing ulcers demand new treatment regimes. The here introduced optimized protocols for transdifferentiation of ASC into keratinocyte-like cells may help to establish more effective treatment procedures.


Subject(s)
Adipocytes/cytology , Cell Transdifferentiation/physiology , Keratinocytes/cytology , Stem Cells/cytology , Adipocytes/physiology , Cells, Cultured/cytology , Culture Media, Conditioned , Flow Cytometry , Humans , Immunohistochemistry , Keratinocytes/physiology , Real-Time Polymerase Chain Reaction/methods , Sensitivity and Specificity , Stem Cells/physiology
6.
Hautarzt ; 63(4): 325-8, 2012 Apr.
Article in German | MEDLINE | ID: mdl-22068935

ABSTRACT

In the context of increasing travel to the tropics, outpatient services are more frequently confronted with non-domestic diseases in Europe. A 3-year old child presented with a painful tumor of the scalp. After incision of the furuncle-like lesion, we extracted a larva of the botfly Dermatobia hominis. Botflies are mainly encountered in Central and South America; they should be considered if patients demonstrate a furuncle-like lesion and have returned from a holiday in these endemic regions.


Subject(s)
Diptera , Scalp Dermatoses/diagnosis , Scalp Dermatoses/therapy , Skin Diseases, Parasitic/diagnosis , Skin Diseases, Parasitic/therapy , Travel , Animals , Child, Preschool , Humans , Scalp Dermatoses/parasitology , Skin Diseases, Parasitic/parasitology , Treatment Outcome
7.
Br J Dermatol ; 164(1): 182-6, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21091942

ABSTRACT

BACKGROUND: The main function of the human sebaceous gland is sebum excretion. Increased sebum levels combined with follicular hyperkeratinization are a prerequisite of acne vulgaris. As peroxisome proliferator-activated receptors (PPARs) are known to control lipid metabolism in several human tissues they have been considered to be involved in the pathogenesis of acne vulgaris. OBJECTIVES: To investigate the effect of activators of PPAR-α (WY14643), PPAR-γ (rosiglitazone) and PPAR-δ (L-165.041) on basal and staurosporine-induced apoptosis in the human sebocyte cell line SZ95 in vitro. METHODS: After defining the basal effects of PPAR activators on membrane integrity (lactate dehydrogenase release) and DNA synthesis (5-bromodeoxyuridine incorporation), apoptosis was determined by the release of histone-associated DNA fragments. The underlying signalling events were detected by Western blotting and the use of specific inhibitors against p44/42 and protein kinase B (PKB)/Akt. RESULTS: PPAR activators of all three subsets offer antiapoptotic effects, with L-165.041 being the most potent. This compound induced the activation of PKB/Akt and p44/42, two kinases involved in antiapoptosis and proliferation, respectively. An inhibition of these kinases by specific inhibitors reversed the suppression of histone-associated DNA fragments by L-165.041, indicating that these signalling pathways participate in the observed antiapoptotic effect. CONCLUSIONS: The present data suggest that activators of PPAR, in particular of the δ subset, might have beneficial effects on acne vulgaris by inhibiting the release of lipids in the context of sebocyte apoptosis.


Subject(s)
Acne Vulgaris/drug therapy , Apoptosis/drug effects , Peroxisome Proliferator-Activated Receptors/pharmacology , Phenoxyacetates/pharmacology , Pyrimidines/pharmacology , Sebaceous Glands/cytology , Thiazolidinediones/pharmacology , Blotting, Western , Bromodeoxyuridine/metabolism , Cell Line/drug effects , Enzyme Inhibitors/pharmacology , Humans , L-Lactate Dehydrogenase/metabolism , PPAR alpha/pharmacology , PPAR delta/pharmacology , PPAR gamma/pharmacology , Rosiglitazone , Sebaceous Glands/drug effects , Staurosporine/pharmacology
8.
Handchir Mikrochir Plast Chir ; 41(6): 327-32, 2009 Dec.
Article in German | MEDLINE | ID: mdl-19711256

ABSTRACT

A cell-based wound coverage with keratinocytes and fibroblasts on the basis of a commercially available dermal substitute (Matriderm ((R)), Kollagen/Elastin matrix) was generated, in order to treat wide burn wounds. First the expansion of keratinocytes was optimised and the culturing time was minimised. Raw material was 1-2 cm (2) split skin. Dermis and epidermis were separated by enzymatic treatment with thermolysin. After treatment of both compartments with trypsin and collagenase I, keratinocytes and fibroblasts were isolated and expanded in collagen I coated dishes. After 10 days fibroblasts were seeded on Matriderm ((R)). After cultivation of the fibroblasts-containing matrix for one week keratinocytes were seeded on top. After an additional week of submersed cultivation the matrix was lifted up to the air-liquid interface to initiate epidermal cell differentiation. After 16 days in the air-liquid interphase the matrix was fixed and underwent immunohistochemical and electron microscopic analysis. Histological analysis showed a regularly stratification of the epidermal part. We observed collagen IV, a marker for the basement membrane, between epidermis and dermis. Desmoglein and the differentiation markers involucrine and cytokeratin 10 were found in the suprabasal layers of the epidermis. Electron microscopic analysis showed the basement membrane in the epidermal junction zone as well as cell-cell connections in the form of desmosomes. Late differentiation characteristics, like granular structures and the cornified layer, were found in the stratum granulosum and stratum corneum. Our results demonstrate that a skin equivalent can be generated by using a collagen/elastin matrix, with an expansion rate of 50-100-fold. This skin equivalent may be useful for covering deep wounds.


Subject(s)
Burns/surgery , Collagen , Elastin , Fibroblasts/transplantation , Keratinocytes/transplantation , Skin, Artificial , Tissue Engineering , Basement Membrane/pathology , Burns/pathology , Collagen/ultrastructure , Collagen Type IV/analysis , Desmogleins/analysis , Elastin/ultrastructure , Epidermis/pathology , Fibroblasts/pathology , Humans , Keratinocytes/pathology , Microscopy, Electron , Microscopy, Fluorescence , Protein Precursors/analysis , Skin/pathology
10.
J Invest Dermatol ; 117(6): 1430-6, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11886504

ABSTRACT

Peroxisome proliferator-activated receptors (PPAR) are members of a nuclear receptor superfamily, which were initially described in the context of fatty acid degradation and adipocyte differentiation. In this study we tested the hypothesis that peroxisome proliferator-activated receptor activation also controls inflammation. In an in vitro model with human keratinocytes inflammation was mimicked by irradiation with ultraviolet B light (150 mJ per cm(2)). Activators for PPAR-alpha (WY-14,643, clofibrate) were shown to reverse ultraviolet-B-light-mediated expression of inflammatory cytokines (interleukin-6, interleukin-8). An activator preferentially for PPAR-beta (bezafibrate) did not show prominent effects on interleukin-6 and interleukin-8 expression. The anti-inflammatory action of WY-14,643 on skin cells was further demonstrated by in vivo testings in which topically applied WY-14,643 markedly increased the minimal erythema dose in ultraviolet-B-irradiated skin. Additionally, it was shown that ultraviolet B irradiation led to a decrease of all three peroxisome proliferator-activated receptor subsets at the mRNA level. Also transactivation of peroxisome proliferator response element was attenuated by ultraviolet B irradiation. The downregulation of peroxisome proliferator-activated receptors by ultraviolet B irradiation provides a possible mechanism that leads to exaggerated and prolonged inflammation. This work suggests the possibility of PPAR-alpha activators as novel nonsteroidal anti-inflammatory drugs in the topical treatment of common inflammatory skin diseases such as atopic dermatitis, psoriasis, and photodermatitis.


Subject(s)
Dermatitis/metabolism , Receptors, Cytoplasmic and Nuclear/genetics , Receptors, Cytoplasmic and Nuclear/metabolism , Skin/radiation effects , Transcription Factors/genetics , Transcription Factors/metabolism , Cell Division/drug effects , Cell Line, Transformed , DNA Primers , Down-Regulation/radiation effects , Erythema/metabolism , Gene Expression/immunology , Gene Expression/radiation effects , Humans , Interleukin-6/genetics , Interleukin-8/genetics , Keratinocytes/cytology , Keratinocytes/metabolism , Keratinocytes/radiation effects , Peroxisome Proliferators/pharmacology , Pyrimidines/pharmacology , Response Elements/physiology , Skin/cytology , Skin/immunology , Ultraviolet Rays/adverse effects
11.
Biochem Biophys Res Commun ; 276(2): 571-8, 2000 Sep 24.
Article in English | MEDLINE | ID: mdl-11027515

ABSTRACT

Changes in the osmolarity of the airway surface fluid have been described to be involved in the pathogenesis of exercise induced asthma, and are suggested as the major cause of the lung disease in cystic fibrosis. In this study, we examined the signaling pathway of hyperosmotic challenge to interleukin-8 (IL-8). Hyperosmolarity (NaCl) caused a time- and concentration-dependent increase in IL-8 expression and secretion in bronchial epithelial cells. These effects could be blocked by antioxidants, such as DMSO, DMTU, DTT, and beta-mercaptoethanol, suggesting an involvement of reactive oxygen intermediates (ROI) in the signal transduction of hyperosmolarity-induced IL-8 synthesis. Since IL-8 is regulated by MAP kinases, we examined the influence of MAP kinase inhibitors on hyperosmolarity-induced IL-8 expression. The results show that this induction is regulated by p38 MAPK and not by ERK1/2. Furthermore, antioxidants blocked the activation of p38 MAPK induced by hyperosmolarity. These results suggest that ROIs are critical for p38 MAPK mediated IL-8 expression by hyperosmolarity.


Subject(s)
Bronchi/metabolism , Interleukin-8/biosynthesis , Reactive Oxygen Species/metabolism , Antioxidants/pharmacology , Bronchi/cytology , Cells, Cultured , Dose-Response Relationship, Drug , Epithelial Cells/metabolism , Humans , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3 , Mitogen-Activated Protein Kinases/metabolism , Osmolar Concentration , Osmotic Pressure , Phosphorylation , Time Factors , p38 Mitogen-Activated Protein Kinases
12.
Pigment Cell Res ; 13(4): 278-80, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10952396

ABSTRACT

Cells of human epidermis are permanently targeted by mechanical stimuli. Besides mechanical forces from external sources the body itself generates mechanical forces via muscle contractions and growth processes. Recently, it was demonstrated that mechanical stretch is connected to enhanced proliferation in epidermal cells. The underlying biochemical events are still a matter of debate. Here we show that mechanical stretch leads to activation of both ERK1/2 and SAPK/JNK in human melanocytes and keratinocytes. In response to a 5 min single stretch ERK1/2 becomes moderately induced in melanocytes and peaked 30 min after the stimulus. In keratinocytes strong activation of ERK1/2 is present directly after the stimulus. SAPK/JNK shows the same activation pattern in both cell species--a slow but steady activation. The different kinetics of both MAPK suggest that different signalling cascades were activated. Future studies should evaluate the relevance of stretch-dependent MAPK activation in triggering the cell proliferation.


Subject(s)
DNA-Binding Proteins , Melanocytes/enzymology , Melanocytes/physiology , Mitogen-Activated Protein Kinases/metabolism , Transcription Factors , Cell Line , Cell Size , Cells, Cultured , Enzyme Activation , Fetus , Humans , JNK Mitogen-Activated Protein Kinases , Keratinocytes/enzymology , Keratinocytes/physiology , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3 , Phosphorylation , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-jun/metabolism , Stress, Mechanical , ets-Domain Protein Elk-1
13.
Med Microbiol Immunol ; 188(4): 177-84, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10917154

ABSTRACT

Heterogeneities in the density of hepatitis C virus (HCV)-RNA-carrying material from human sera (1.03-1.20 g/ml) are partially due to the binding of lipoproteins [low density (LDL), very low density (VLDL), high density (HDL) lipoproteins] and immunoglobulins. In this study we demonstrate the binding of recombinant HCV envelope protein (El/E2) to human LDL, VLDL and HDL on a molecular basis. The binding of lipoproteins was restricted to the middle part of the El gene product (amino acids 222-336) and the C-terminal part of the E2 protein (amino acids 523-809). Lipoproteins did not bind to recombinant HCV core protein.


Subject(s)
Hepacivirus/metabolism , Lipoproteins, HDL/metabolism , Lipoproteins, LDL/metabolism , Lipoproteins, VLDL/metabolism , Viral Envelope Proteins/metabolism , Animals , Baculoviridae , Genetic Vectors , Hepacivirus/genetics , Humans , Protein Binding , Rabbits , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Reticulocytes/metabolism , Viral Envelope Proteins/genetics
14.
J Invest Dermatol ; 114(3): 408-12, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10692097

ABSTRACT

Cells within human skin are permanently exposed to mechanical stretching. Here we present evidence that alterations in cell shape trigger biochemical signaling via MAP kinases in human keratinocytes. In an in vitro attempt we demonstrate a fast but transient activation of extracellular signal-regulated kinases 1/2 in response to cell stretch. This activation is reversed by preincubation with functional blocking antibodies directed towards beta1-integrins. As a second member of MAP kinases, stress-activated protein kinase/c-JUN NH2-terminal kinase was activated in a slower fashion, peaking at 1 h after the initial stimulus. The delay in signal transmission suggests that extracellular signal-regulated kinases 1/2 and stress-activated protein kinase/c-JUN NH2-terminal kinase do not share the same signaling pathway. p38 was not activated by cell stretching. The contribution of cytoskeletal elements in signal perception and transduction was evaluated by selective disruption of either actin filaments, microtubules, or keratin filaments but showed no clear effect on stretch-induced activation of extracellular signal-regulated kinases 1/2 and stress-activated protein kinase/c-JUN NH2-terminal kinase. In conclusion we found evidence of a cell-shape-dependent activation of MAP kinases in human keratinocytes disclosing beta1-integrins as putative mechano-transducers. It is likely that alterations of skin mechanics in vivo underlying pathogenic processes like wound formation and healing trigger physiologic responses via the MAP kinase pathway.


Subject(s)
Keratinocytes/physiology , MAP Kinase Signaling System , Cell Line , Cytoskeleton/physiology , DNA/biosynthesis , Enzyme Activation/drug effects , Humans , Integrin beta1/pharmacology , Keratinocytes/enzymology , Mitogen-Activated Protein Kinase 3 , Mitogen-Activated Protein Kinases/metabolism , Stress, Mechanical
15.
Pigment Cell Res ; 12(4): 246-51, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10454292

ABSTRACT

Human skin is repeatedly exposed to mechanical stretching in vivo, but in an ordinary culture of skin cells this prominent feature has been neglected. In order to study whether mechanical stretching plays a role for human melanocytes, we have established a culture technique to mimic this physical stretching: primary cultures of human melanocytes were plated on silicon supports, which undergo a stretching of about 10% of the initial length. After application of repeated stretching and relaxation for 4 days, cell count was significantly (about 40%) enhanced. In addition, we found approximately 2-fold increase in heat shock protein (HSP) 90, both at the protein and mRNA level. HSP 90 is known to bind to Raf-1 and, therefore, may contribute to the Raf-1-MEK (mitogen-activated protein-kinase kinase)-MAPK (mitogen-activated protein-kinase) signaling pathway. Disruption of the Raf-1-HSP 90 multimolecular complex by geldanamycin lead to a considerable decrease in melanocyte cell count. However, geldanamycin did not reverse the stretch-induced growth stimulation. Therefore, the stretch-mediated up-regulation of HSP 90 expression in melanocytes appears to be independent of stretch-mediated growth stimulation. These findings have strong implications for the in vitro cultivation of melanocytes for transplantation purposes.


Subject(s)
HSP90 Heat-Shock Proteins/metabolism , Melanocytes/cytology , Melanocytes/metabolism , Cell Division , Cells, Cultured , HSP90 Heat-Shock Proteins/genetics , Humans , Skin/embryology , Stress, Mechanical , Up-Regulation
16.
Clin Chem ; 45(5): 619-24, 1999 May.
Article in English | MEDLINE | ID: mdl-10222347

ABSTRACT

BACKGROUND: To monitor gene therapy, we wished to quantify cystic fibrosis transmembrane conductance regulator (CFTR) mRNA. We developed a PCR-based method to measure CFTR mRNA in clinical samples. METHODS: Expression was determined by reverse transcription-competitive multiplex PCR (RCMP) for CFTR and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) transcripts, and for serial dilutions of two internal cDNA standards consisting of CFTR and GAPDH mutants containing short deletions. The RCMP used simultaneous amplification of the gene of interest with a reporter gene in one reaction tube. The expression of CFTR was calculated with reference to the amount of GAPDH to correct for variations in initial RNA loading. RESULTS: Amplification of cDNAs derived from different amounts of RNA (1-4 microgram) gave similar GAPDH/CFTR ratios, with a coefficient of variation (CV) below 7.5%. RCMP was applied on nasal and bronchial brushings and shows a high variability of CFTR expression in non-cystic fibrosis donors. CONCLUSION: This method is precise and reproducible and advantageous for use with limited amounts of tissue, such as from biopsies or from nasal or bronchial brushings.


Subject(s)
Cystic Fibrosis Transmembrane Conductance Regulator/analysis , RNA, Messenger/analysis , Bronchi/chemistry , Bronchi/cytology , Cells, Cultured , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Electrophoresis, Agar Gel , Glyceraldehyde-3-Phosphate Dehydrogenases/analysis , Glyceraldehyde-3-Phosphate Dehydrogenases/genetics , Humans , Mutation , Nose/chemistry , Nose/cytology , Reproducibility of Results , Reverse Transcriptase Polymerase Chain Reaction , Sensitivity and Specificity
17.
Photochem Photobiol ; 69(2): 218-21, 1999 Feb.
Article in English | MEDLINE | ID: mdl-10048312

ABSTRACT

Extracts of Hypericum perforatum (St. John's wort) are used in the treatment of depression. They contain the plant pigment hypericin and hypericin derivates. These compounds have light-dependent activities. In order to estimate the potential risk of phototoxic skin damage during antidepressive therapy, we investigated the phototoxic activity of hypericin extract using cultures of human keratinocytes and compared it with the effect of the well-known phototoxic agent psoralen. The absorbance spectrum of our Hypericum extract revealed maxima in the whole UV range and in parts of the visible range. We cultivated human keratinocytes in the presence of different Hypericum concentrations and irradiated the cells with 150 mJ/cm2 UVB, 1 J/cm2 UVA or 3 h with a white light of photon flux density 2.6 mumol m-2 s-1. The determination of the bromodeoxyuridine incorporation rate showed a concentration- and light-dependent decrease in DNA synthesis with high hypericin concentrations (> or = 50 micrograms/mL) combined with UVA or visible light radiation. In the case of UVB irradiation a clear phototoxic cell reaction was not detected. We found phototoxic effects even with 10 ng/mL psoralen using UVA with the same study design as in the case of the Hypericum extract. These results confirm the phototoxic activity of Hypericum extract on human keratinocytes. However, the blood levels that are to be expected during antidepressive therapy are presumably too low to induce phototoxic skin reactions.


Subject(s)
Antidepressive Agents/adverse effects , Dermatitis, Phototoxic , Ficusin/adverse effects , Keratinocytes/drug effects , Perylene/analogs & derivatives , Photosensitizing Agents/adverse effects , Plant Extracts/toxicity , Quercetin/analogs & derivatives , Xanthenes/adverse effects , Cells, Cultured , Humans , Hypericum , Perylene/adverse effects , Plants, Medicinal , Quercetin/adverse effects , Spectrophotometry, Atomic , Ultraviolet Rays
18.
J Invest Dermatol ; 110(4): 364-7, 1998 Apr.
Article in English | MEDLINE | ID: mdl-9540976

ABSTRACT

We have introduced a reverse transcriptase polymerase chain reaction based method to measure mRNA levels of the melanogenesis enzymes tyrosinase, tyrosinase-related-protein 1 (TRP-1), and tyrosinase-related-protein 2 (TRP-2). Expression was determined by reverse transcriptase-competitive multiplex polymerase chain reaction of (i) melanogenesis enzyme transcripts and the "housekeeping" gene glyceraldehyde-3-phosphate dehydrogenase, and (ii) two internal standards consisting of mutated melanogenesis enzyme cDNA and mutated gene glyceraldehyde-3-phosphate dehydrogenase cDNA. This was investigated on in vitro cultured melanocytes in the presence of three different steroids; one glucocorticoid (betamethasone-17-valerate) and two sex steroids (diethylstilbestrol and estradiol). All three steroids lead to an increase of about 1.5-2.5-fold of tyrosinase transcripts. The amount of TRP-1 transcripts was likewise enhanced, but only moderately (approximately 1.5-fold). In contrast, TRP-2 transcripts were reduced by approximately 40% in number after betamethasone-17-valerate treatment, whereas the two sex steroids, diethylstilbestrol and estradiol, caused an upregulation of about 20-fold of the initial TRP-2 transcript level. We therefore suggest that hyperpigmentation during pregnancy or under contraceptive treatment is mediated by a direct induction of melanogenesis via sex steroids.


Subject(s)
Hormones/pharmacology , Intramolecular Oxidoreductases/genetics , Melanocytes/metabolism , Membrane Glycoproteins , Monophenol Monooxygenase/genetics , Oxidoreductases , Proteins/genetics , RNA, Messenger/metabolism , Betamethasone/pharmacology , Cell Line , Diethylstilbestrol/pharmacology , Estradiol/pharmacology , Humans , Melanocytes/cytology , Melanocytes/drug effects , Polymerase Chain Reaction/methods , Transcription, Genetic
19.
Acta Derm Venereol ; 78(2): 136-8, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9534893

ABSTRACT

A variety of grafting procedures using autologous melanocytes have achieved promising results in the treatment of vitiligo. We here report on the preparation of an adequate graft recipient bed by pulsed Erbium-YAG laser skin ablation. In particular, for irregular lesions on delicate sites, which cannot be approached by utilization of suction blisters or dermabrasion, this technique may offer a distinct advantage.


Subject(s)
Laser Therapy , Melanocytes/transplantation , Skin Transplantation/methods , Vitiligo/pathology , Vitiligo/surgery , Adult , Cells, Cultured , Female , Humans , Male , Middle Aged
20.
Pigment Cell Res ; 11(1): 34-7, 1998 Feb.
Article in English | MEDLINE | ID: mdl-9523333

ABSTRACT

In human epidermis one dendritic melanocyte interacts with about 36 keratinocytes and supplies them with melanin. In contrast to the vivo situation melanocytes in culture are far less dendritic. In the present study different culture systems were tested in order to observe the mechanism of melanocyte dendrite formation. In particular, we focused on the role of keratinocytes in this process. Time lapse studies revealed that only differentiated keratinocytes enhance melanocyte dendricity. Differentiated keratinocytes form connected cell sheets, which attach to part of the melanocyte plasma membrane. By contraction and retraction of keratinocyte units, new dendrites were drawn out from the melanocytes. Melanocytes remain passive during this process, which is indicated by the observation that sometimes extended dendrites could not withstand the tension and shear.


Subject(s)
Dendritic Cells/cytology , Keratinocytes/cytology , Melanocytes/cytology , Calcium/pharmacology , Cell Differentiation/drug effects , Cells, Cultured , Coculture Techniques , Culture Media , Dendritic Cells/drug effects , Epidermal Growth Factor/pharmacology , Humans , Keratinocytes/drug effects , Melanocytes/drug effects
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