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- Haak-Frendscho, M, et al.
(author)
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Histidine decarboxylase expression in human melanoma.
- 2000
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In: Journal of Investigative Dermatology. - : Elsevier BV. - 0022-202X .- 1523-1747. ; 115:3, s. 345-52
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Journal article (peer-reviewed)abstract
- Histamine has been implicated as one of the mediators involved in regulation of proliferation in both normal and neoplastic tissues. Histidine decarboxylase, the only enzyme that catalyzes the formation of histamine from L-histidine, is an essential regulator of histamine levels. In this study, we investigated the gene and protein expression of histidine decarboxylase in melanoma. Reverse transcriptase polymerase chain reaction and in situ hybridization studies of WM-35, WM-983/B, HT-168, and M1 human melanoma cell lines both resulted in positive signals for histidine decarboxylase messenger RNA. A polyclonal chicken antibody was developed against human histidine decarboxylase and protein expression was confirmed by western blot analysis of the cell lysates, revealing a predominant immunoreactive band at approximately 54 kDa corresponding to monomeric histidine decarboxylase. Protein expression of histidine decarboxylase was also shown by flow cytometric analysis and strong punctate cytoplasmic staining of melanoma cell lines. Moreover, both primary and metastatic human melanoma tissues were brightly stained for histidine decarboxylase. When compared with the very weak or no reactions on cultivated human melanocytes both western blot and immunohistochemical studies showed much stronger histidine decarboxylase expression in melanoma cells. These findings suggest that expression of histidine decarboxylase is elevated in human melanoma.
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- Kis, K, et al.
(author)
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Budesonide, but not tacrolimus, affects the immune functions of normal human keratinocytes.
- 2006
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In: International Immunopharmacology. - : Elsevier BV. - 1567-5769 .- 1878-1705. ; 6:3, s. 358-68
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Journal article (peer-reviewed)abstract
- Topical immunosuppressant therapy is widely used in the treatment of inflammatory skin diseases such as psoriasis and atopic dermatitis. Besides its beneficial therapeutic effects, application of topical anti-inflammatory drugs may render the epidermis more vulnerable to invading pathogens by suppressing innate immune responses in keratinocytes, such as cytokine production and Toll-like receptor (TLR) expression. In order to evaluate and compare the immunosuppressive effects of different immunosuppressant drugs on keratinocytes, we treated lipopolysaccharide (LPS)-stimulated and -unstimulated normal human keratinocytes with the synthetic corticosteroid budesonide and the macrolide tacrolimus. The expressions of the pattern recognition receptors (PRRs) TLR2 and TLR4 were measured by quantitative RT-PCR, pro-inflammatory cytokines IL-1alpha, IL-8 and TNF-alpha were monitored by quantitative RT-PCR and by ELISA, and alterations in TLR2 protein level were measured by flow cytometry. Budesonide had a suppressive effect on both constitutive and LPS-induced IL-8 gene expression. The amount of TNF-alpha mRNA was diminished in unstimulated keratinocytes, while TLR2 mRNA expression was markedly enhanced both in unstimulated and LPS-treated cells after incubation with budesonide. This increase in TLR2 mRNA expression was also detectable at the protein level in LPS-stimulated cells. Tacrolimus had no effect on any of the examined genes. Budesonide, but not tacrolimus, significantly inhibited the NF-kappaB-dependent luciferase reporter activity in HaCaT cells after induction with LPS or TNF-alpha. Although tacrolimus and budesonide are both effective treatments in some inflammatory skin diseases, the data provided here imply differences in local therapeutic and adverse effects of these two topical immunosuppressants.
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- Szolnoky, G, et al.
(author)
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A mannose-binding receptor is expressed on human keratinocytes and mediates killing of Candida albicans.
- 2001
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In: Journal of Investigative Dermatology. - : Elsevier BV. - 0022-202X .- 1523-1747. ; 117:2, s. 205-13
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Journal article (peer-reviewed)abstract
- Human keratinocytes are known to kill Candida albicans in vitro, but the mechanism of killing is not yet understood. Here, we demonstrate that spontaneous, ultraviolet-B-light-induced, alpha-melanocyte-stimulating-hormone-induced, and interleukin-8-induced Candida killing by keratinocytes can be inhibited with mannan and mannosylated bovine serum albumin (Man-BSA). A polyclonal goat serum raised against the human macrophage mannose receptor stained suprabasal keratinocytes, but no staining was observed on keratinocytes with a monoclonal antibody (mAb15) specific for the human macrophage mannose receptor. Mannose-affinity chromatography of keratinocyte extract isolated a 200 kDa protein, and on the Western blot the goat antiserum reacted with a 200 kDa protein. In radioligand binding studies, the binding of 125I-Man-BSA to human keratinocytes was inhibited by mannan in a concentration-dependent manner. Analysis of the binding revealed a single class keratinocyte mannose receptor with a KD of 1.4 x 10(-8) M and a Bmax of 1 x 10(4) binding sites per cell. The binding of 125I-Man- BSA to keratinocytes proved to be time-dependent, acid-precipitable, and Ca2+- and trypsin-sensitive. After trypsinization the receptors underwent a rapid recovery at 37 degrees C. These results demonstrate the presence of mannose receptor on human keratinocytes, and its active involvement in the killing of Candida albicans.
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- Farkas, A, et al.
(author)
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Dithranol upregulates IL-10 receptors on the cultured human keratinocyte cell line HaCaT.
- 2001
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In: Inflammation Research. - : Springer Science and Business Media LLC. - 1023-3830 .- 1420-908X. ; 50:1, s. 44-9
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Dithranol is highly effective in the treatment of psoriasis, however its mode of action is still not well known. Since interleukin-8 and interleukin-10 are involved in the pathogenesis of psoriasis, the aim of our study was to investigate the effect of dithranol on interleukin-8, interleukin-10 mRNA production and interleukin-10 receptor expression of the HaCaT keratinocyte cell line which is commonly used in experiments examining the effects of therapeutic drugs on keratinocytes.MATERIALS AND METHODS: Cultured HaCaT cells were treated with 0.1-0.5 microg/ml dithranol for 30 minutes. After 2 and 4 h total cellular RNA isolated from HaCaT cells was reverse transcribed (RT) to cDNA which was subjected to polymerase chain reaction (PCR) with specific primer pairs for interleukin-8, interleukin-10 and interleukin-10 receptor. For immunohistochemistry cultured HaCaT cells were stained with a monoclonal antibody against the human interleukin-10 receptor.RESULTS: Our results showed that dithranol treatment did not change the highly elevated level of interleukin-8 mRNA of HaCaT cells. Interleukin-10 mRNA signal with RT-PCR could not be detected in HaCaT cells. Depending on the concentration dithranol increased the mRNA production of interleukin-10 receptors in HaCaT cells. This dithranol induced dose dependent upregulation of IL-10 receptors in HaCaT cells was also observed on the protein level using immunohistochemistry.CONCLUSIONS: Since the interleukin-10 receptor expression of keratinocytes in psoriatic lesional skin is downregulated, the dithranol induced upregulation of the receptor in our model system might help to reveal the therapeutic action of the drug.
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| 11. |
- Koreck, A, et al.
(author)
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The role of innate immunity in the pathogenesis of acne.
- 2003
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In: Dermatology. - : S. Karger AG. - 1018-8665 .- 1421-9832. ; 206:2, s. 96-105
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Journal article (peer-reviewed)abstract
- Acne is a multifactorial disease of the pilosebaceous follicle. The most significant pathogenetic factors of acne are: abnormal ductal keratinization, increased sebum secretion, abnormalities of the microbial flora and inflammation. The pilosebaceous unit is an immunocompetent organ. Keratinocytes and sebocytes may act as immune cells capable of pathogen recognition and abnormal lipid presentation, and they might have an important role in initiating and perpetuating the activation of both innate and adaptive immune responses. The elements of the skin immune system are involved in the development of both noninflammatory and inflammatory acne lesions.
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- Pivarcsi, A, et al.
(author)
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Innate immune functions of the keratinocytes. A review.
- 2004
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In: Acta microbiologica et immunologica Hungarica. - 1217-8950. ; 51:3, s. 303-10
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Journal article (peer-reviewed)abstract
- Human keratinocytes are known to kill living microbes. They express different pattern recognition receptors (PRRs) such as the Toll-like receptor 2 (TLR2), TLR4, the CD1d molecule and a keratinocyte mannose-binding receptor (KcMR). In response to challenge with microbes or microbial-derived substances the activation and nuclear translocation of NF-kappaB, the production of nitric oxide (NO) and inflammatory cytokines occur in keratinocytes, in a TLR-dependent manner. Blocking of NF-kappaB activation or NO production inhibit the Candida albicans-killing activity of keratinocytes. This Candida killing activity could be inhibited by blocking of KcMR. Recognition of invading pathogens in the epidermis triggers cytokine production in keratinocytes leading to elimination of pathogens and the activation of the adaptive immune system. These findings stress the importance of the role of keratinocytes in innate immunity.
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| 15. |
- Pivarcsi, A, et al.
(author)
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Serum factors regulate the expression of the proliferation-related genes alpha5 integrin and keratin 1, but not keratin 10, in HaCaT keratinocytes.
- 2001
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In: Archives of Dermatological Research. - : Springer Science and Business Media LLC. - 0340-3696 .- 1432-069X. ; 293:4, s. 206-13
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Journal article (peer-reviewed)abstract
- In the highly coordinated programme of gene expression during keratinocyte proliferation and differentiation, alpha5 integrin and keratins 1 and 10 (K1/K10) may play important regulatory roles. We were interested in seeing whether, in continuously growing, immortalized HaCaT keratinocytes, similar to normal keratinocytes, the expression of alpha5 integrin and K1/K10 was related to cell proliferation and differentiation. After release from cell quiescence the expression of alpha5 integrin, both at the mRNA and protein levels, was upregulated in the cells. At the same time, K1/K10 mRNA and protein expression decreased dramatically, while the mRNA for D1 cyclin became detectable, and the cells became highly proliferative. These findings indicate that alpha5 integrin and K1/K10 are involved in the regulation of HaCaT proliferation and differentiation, as in normal keratinocytes. However, HaCaT cells are different from normal keratinocytes in their ability to lose K1/K10 expression. There is no evidence that the expression of K1/K10 can be reversed in normal keratinocytes. This ability of dedifferentiation might be a unique feature of HaCaT cells and may be a key component of their immortalized nature. We also found that serum factors regulate mRNA expression of alpha5 integrin and K1, but not of K10, in HaCaT cells. This information could be relevant to the understanding of normal epidermal differentiation.
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| 18. |
- Wang, GY, et al.
(author)
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Immunostimulatory sequence CpG elicits Th1-type immune responses in inflammatory skin lesions in an atopic dermatitis murine model
- 2008
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In: International archives of allergy and immunology. - : S. Karger AG. - 1423-0097 .- 1018-2438. ; 147:1, s. 41-51
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Journal article (peer-reviewed)abstract
- <i>Background:</i> Atopic dermatitis (AD) is a chronic inflammatory skin disease, for which no fundamental therapy exists. Immunostimulatory sequence CpG (ISS CpG) has potential in reducing susceptibility to allergic diseases and reversing established allergic reactions. <i>Objective:</i> To investigate the effects of ISS CpG in the prevention and treatment of AD in an AD murine model. <i>Methods:</i> BALB/c mice were epicutaneously exposed to ovalbumin (OVA) for 3 or 4 weeks with a 2-week resting period between each exposure week. ISS i.d. injection was given either on the 1st day of each exposure week (in the prevention experiment) or 3 days before and on the 1st, 4th and 7th day of the last exposure week (in the treatment experiment). Skin biopsy and blood were obtained at the end of the experiments. <i>Results:</i> ISS CpG treatment increased drastically mRNA expression of proinflammatory and Th1-type cytokines and chemokines in OVA-treated skin both in the prevention and treatment experiments. The suppressing effect of ISS CpG on Th2-type cytokines and chemokines was weak and limited to IL-13 and CCL24 in the treatment experiment. No significant reduction in OVA-elicited infiltration of eosinophils and T cells in the skin was seen after ISS administration but infiltration of plasmacytoid dendritic cells was absent in ISS CpG-treated skin. In contrast, ISS injection elicited dramatic infiltration of F4/80+ and CCR5+ cells into the dermis and subcutaneous tissue. <i>Conclusion:</i> Due to unwanted side effects and minor beneficial effects in our model, administration of ISS CpG may not be suitable for the treatment of AD in humans.
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