| 1. |
- Alanazi, Sultan, et al.
(author)
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Mast Cell β-Tryptase Is Enzymatically Stabilized by DNA
- 2020
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In: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 21:14
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Journal article (peer-reviewed)abstract
- Tryptase is a tetrameric serine protease located within the secretory granules of mast cells. In the secretory granules, tryptase is stored in complex with negatively charged heparin proteoglycans and it is known that heparin is essential for stabilizing the enzymatic activity of tryptase. However, recent findings suggest that enzymatically active tryptase also can be found in the nucleus of murine mast cells, but it is not known how the enzmatic activity of tryptase is maintained in the nuclear milieu. Here we hypothesized that tryptase, as well as being stabilized by heparin, can be stabilized by DNA, the rationale being that the anionic charge of DNA could potentially substitute for that of heparin to execute this function. Indeed, we showed that double-stranded DNA preserved the enzymatic activity of human β-tryptase with a similar efficiency as heparin. In contrast, single-stranded DNA did not have this capacity. We also demonstrated that DNA fragments down to 400 base pairs have tryptase-stabilizing effects equal to that of intact DNA. Further, we showed that DNA-stabilized tryptase was more efficient in degrading nuclear core histones than heparin-stabilized enzyme. Finally, we demonstrated that tryptase, similar to its nuclear localization in murine mast cells, is found within the nucleus of primary human skin mast cells. Altogether, these finding reveal a hitherto unknown mechanism for the stabilization of mast cell tryptase, and these findings can have an important impact on our understanding of how tryptase regulates nuclear events.
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| 2. |
- Forsberg, Sofi, et al.
(author)
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Comparison of growth-inhibitory agents by fluorescence imaging of human skin re-epithelialization in vitro
- 2006
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In: Acta Dermato-Venereologica. - : Medical Journals Sweden AB. - 0001-5555 .- 1651-2057. ; 86:4, s. 292-299
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Journal article (peer-reviewed)abstract
- Drug screening procedures should preferably utilize experimental settings mimicking the in vivo situation. The aim of this study was to evaluate a skin explant model as a tool to identify topical agents with anti-proliferative properties in human epidermis. Re-epithelialization was initiated from a skin punch biopsy explanted onto de-epidermized dermis and cultured at the air-liquid interface in the presence of the epidermal growth factor receptor kinase inhibitor PKI166, tacrolimus or established topical anti-psoriatic drugs: betamethasone, calcipotriol, dithranol and tazarotene. Neo-epidermal extension was traced by fluorescence microscopy prior to histomorphometric analysis. PKI166 at 1 mu M decreased the mean radial outgrowth rate (-19%), frequency of BrdU-positive (-37%) and laminin 5-positive (-45%) cells, indicating reduced proliferation and migration of neo-epidermal keratinocytes. However, the papillomatosis index and epithelial thickness were not significantly affected. Calcipotriol at 1 mu M had a similar effect on the outgrowth rate (-15%) and fraction of laminin 5-stained keratinocytes (-40%). Furthermore, calcipotriol significantly reduced mean neo-epidermal thickness. Equimolar concentrations of the other test compounds had no apparent effect on histology or outgrowth parameters. This study exemplifies the versatility of combined dynamic and morphological analysis and emphasizes the potential of epidermal growth factor receptor-directed inhibition in hyperproliferative disorders of the epidermis.
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| 3. |
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| 4. |
- Forsberg, Sofi, 1980-
(author)
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Human Epidermal Growth Factor Receptors and Biological Effects of HER-directed Molecules on Skin Epithelialization
- 2009
-
Doctoral thesis (other academic/artistic)abstract
- Human skin forms a biologically active barrier and maintains vital protective functions through continuous regeneration of cells within its outermost layer, the epidermis. In healthy skin, renewal of epithelial cells is a tightly regulated process in which the epidermal growth factor receptor (EGFR or HER1) and its various ligands are involved. The biological role of other EGFR family members (HER2–4) in normal and diseased human skin has gained less interest. The purpose of this work was to investigate the expression and contribution of different HERs in cultured epidermis and psoriatic skin. Epidermal regeneration was studied by fluorescence imaging of a skin explant model exposed to anti-psoriatic drugs, HER ligands or HER-blocking molecules. EGFR, HER2 and HER3 were all markedly expressed with an in vivo-like immunostaining pattern in cultured neoepidermis, whereas only low amounts of HER4 were detected at protein and mRNA levels. Re-epithelialization was associated with receptor activation. Application of HER-selective tyrosine kinase inhibitors and monoclonal antibodies reduced the proliferative activity, receptor phosphorylation and radial outgrowth from normal skin explants. Similar anti-dynamic effects were obtained with HER kinase inhibition of neoepidermis generated from psoriatic skin. Among the HER receptors, EGFR seemed to be the dominant subtype during epithelialization in vitro although HER2 and HER3 were also involved. HER2 probably functioned as a co-receptor for the kinase-deficient HER3 in neoepidermis. In vivo, expression of HER4 mRNA was detected in normal and uninvolved psoriatic skin but was virtually absent in lesional skin, a potentially important finding for HER signalling in psoriasis. This thesis demonstrates the utility of combined dynamic and biochemical analyses of re-epithelialization and highlights the role of EGFR and other HERs for epidermal growth. It also underscores the potential of HER-directed inhibition to control hyperproliferative states of the epidermis.
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| 5. |
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| 6. |
- Forsberg, Sofi, et al.
(author)
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Re-epithelialization from human skin explant cultures is promoted by ligand-activated HER3 receptor
- 2010
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In: Journal of dermatological science (Amsterdam). - : Elsevier BV. - 0923-1811 .- 1873-569X. ; 59:1, s. 7-15
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Journal article (peer-reviewed)abstract
- BACKGROUND: Ligand-stimulated epidermal growth factor receptor (EGFR/HER1) plays a fundamental role in skin biology as potent transducer of mitotic and anti-apoptotic stimuli in keratinocytes. In human epidermis, at least two additional EGFR family members--HER2 and HER3--are expressed but their biological functions in normal and diseased human skin remain obscure. OBJECTIVE: Here, we studied the expression and biological impact of HER3 in regenerating human epidermis formed from skin explants adhered to acellular dermis. METHODS: Neoepidermal HER3 expression was examined by quantitative real-time reverse transcriptase polymerase chain reaction, immunohistochemistry and Western blot analysis. The dynamic effect of HER3 receptor stimulation by recombinant heregulin (HRG)-beta1 was assessed by fluorescence imaging of re-epithelialization. RESULTS: In the neoepidermis, HER3 mRNA and protein were detected with activated receptors being immunolocalized at basal and low suprabasal levels. Exogenous HRG-beta1 at 10-20 ng/ml increased the outgrowth rate corresponding to approximately 30% the response of exogenous EGF. The growth-promoting effect of HRG-beta1 was associated with enhanced HER3 phosphorylation, keratinocyte proliferation and thickening of viable neoepidermis whereas blockade of ligand-binding to HER3 delayed the outgrowth process and inhibited both constitutive and ligand-induced HER3 phosphorylation. HER2 antagonism using an anti-dimerization antibody, pertuzumab, impeded the re-epithelialization rate. In addition, a selective HER2 kinase inhibitor, CP654577, downregulated phospho-HER3 expression suggesting that transactivation of kinase-deficient HER3 was accomplished through dimerization with HER2. CONCLUSION: The study emphasizes the central role of EGFR in epidermal renewal and demonstrates that HRG-activated HER3 contributes to the outgrowth process of epidermis in vitro.
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| 7. |
- Forsberg, Sofi, et al.
(author)
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Regeneration of human epidermis on acellular dermis is impeded by small-molecule inhibitors of EGF receptor tyrosine kinase
- 2008
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In: Archives of Dermatological Research. - : Springer Science and Business Media LLC. - 0340-3696 .- 1432-069X. ; 300:9, s. 505-516
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Journal article (peer-reviewed)abstract
- The family of human epidermal growth factor receptors (EGFR, HER2-4) exerts key functions in normal and malignant epithelial cells. Both EGFR and HER2 are valuable targets for anti-cancer drugs by interfering with ligand binding, receptor dimerization, or tyrosine kinase activity. A similar therapeutic strategy has been advocated for chronic psoriasis since plaque lesions overexpress EGFR and its ligands. Our aim was to characterize EGFR/HER2 protein expression in skin cultures and to evaluate the effects of tyrosine kinase inhibitors on epidermal outgrowth, morphology, and EGFR activation. Human skin explants were established on cell-free dermis and cultured at the air-liquid interface. The impact of small-molecule HER inhibitors on outgrowth was assayed by fluorescence-based image analysis and histometry. Effects of a dual EGFR/HER2 kinase inhibitor, PKI166, on neoepidermis were studied by immunohistochemistry and Western blot. Receptor immunostaining showed in vivo-like distributions with highest EGFR intensity in the proliferative layers whereas HER2 was mainly expressed by suprabasal keratinocytes. Reepithelialization was associated with EGFR autophosphorylation irrespective of exogenous ligand stimulation. PKI166 inhibited neoepidermal EGFR activation, keratinocyte proliferation, and outgrowth from normal and psoriatic skin explants. The rate of epidermalization in presence of other HER inhibitors varied suggesting that drug specificity, potency, and reversibility determine the dynamic outcome. Overall, agents predominantly targeting EGFR kinase were more efficient inhibitors of epidermal regeneration than an HER2-selective drug. The study illustrates the usefulness of a dynamic skin model and emphasizes the potential of HER-directed approaches to control epidermal growth in hyperproliferative skin disorders.
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| 8. |
- Gronberg, Alvar, et al.
(author)
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Treatment with LL-37 is safe and effective in enhancing healing of hard-to-heal venous leg ulcers : a randomized, placebo-controlled clinical trial
- 2014
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In: Wound Repair and Regeneration. - : Wiley. - 1067-1927 .- 1524-475X. ; 22:5, s. 613-621
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Journal article (peer-reviewed)abstract
- Venous leg ulcers (VLUs) are one of the most prevalent types of chronic wounds. The aim of this study was to determine the safety and dose-response efficacy of the human synthetic peptide LL-37 in the treatment of hard-to-heal VLUs. This first-in-man trial included 34 participants with VLUs and comprised a 3-week, open-label, run-in period on placebo, followed by a 4-week randomized double-blind treatment phase with twice weekly applications of LL-37 (0.5, 1.6, or 3.2 mg/mL) or placebo, and a 4-week follow-up. The healing rate constants for 0.5 and 1.6 mg/mL of LL-37 were approximately six-and threefold higher than for placebo (p = 0.003 for 0.5 mg/mL and p = 0.088 for 1.6 mg/mL). Square-root transformed wound area data showed improved healing for the 0.5 and 1.6 mg/mL dose groups compared with pretreatment values (p < 0.001 and p = 0.011, respectively). Consistently, treatment with the two lower doses markedly decreased the mean ulcer area (68% for 0.5 mg/mL and 50% for 1.6 mg/mL groups). No difference in healing was observed between the groups receiving 3.2 mg/mL of LL-37 and placebo. There were no safety concerns regarding local or systemic adverse events. In conclusion, topical treatment with LL-37 for chronic leg ulcers was safe and well tolerated with the marked effect on healing predictors at the two lower doses warranting further investigations.
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| 9. |
- Hagforsen, Eva, et al.
(author)
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Ablation of human skin mast cells in situ by lysosomotropic agents
- 2015
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In: Experimental dermatology. - : Wiley. - 0906-6705 .- 1600-0625. ; 24:7, s. 516-521
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Journal article (peer-reviewed)abstract
- Mast cells are known to have a detrimental impact on numerous types of inflammatory skin diseases such as contact dermatitis, atopic eczema and cutaneous mastocytosis. Regimens that dampen skin mast cell-mediated activities can thus offer an attractive therapeutic option under such circumstances. As mast cells are known to secrete a large array of potentially pathogenic compounds, both from preformed stores in secretory lysosomes (granules) and after de novo synthesis, mere inhibition of degranulation or interference with individual mast cell mediators may not be sufficient to provide an effective blockade of harmful mast cell activities. An alternative strategy may therefore be to locally reduce skin mast cell numbers. Here, we explored the possibility of using lysosomotropic agents for this purpose, appreciating the fact that mast cell granules contain bioactive compounds prone to trigger apoptosis if released into the cytosolic compartment. Based on this principle, we show that incubation of human skin punch biopsies with the lysosomotropic agents siramesine or Leu-Leu methyl ester preferably ablated the mast cell population, without causing any gross adverse effects on the skin morphology. Subsequent analysis revealed that mast cells treated with lysosomotropic agents predominantly underwent apoptotic rather than necrotic cell death. In summary, this study raises the possibility of using lysosomotropic agents as a novel approach to targeting deleterious mast cell populations in cutaneous mastocytosis and other skin disorders negatively influenced by mast cells.
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| 10. |
- Hagforsen, Eva, et al.
(author)
-
Siramesine causes preferential apoptosis of mast cells in skin biopsies from psoriatic lesions
- 2017
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In: British Journal of Dermatology. - : Oxford University Press (OUP). - 0007-0963 .- 1365-2133. ; 177:1, s. 179-187
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Journal article (peer-reviewed)abstract
- BACKGROUND: Skin mast cells are implicated as detrimental effector cells in various inflammatory skin diseases such as contact eczema, atopic dermatitis and psoriasis. Selective reduction of cutaneous mast cells, e.g. by inducing targeted apoptosis, might prove a rational and efficient therapeutic strategy in dermatoses negatively influenced by mast cells.OBJECTIVES: The objective of the present study was to evaluate whether a lysosomotropic agent such as siramesine can cause apoptosis of mast cells present in psoriatic lesions.MATERIALS AND METHODS: Punch biopsies were obtained from lesional and uninvolved skin in 25 patients with chronic plaque psoriasis. After incubation with siramesine, the number of tryptase-positive mast cells and their expression of interleukin (IL)-6 and IL-17 was analysed. Skin biopsies were digested to allow flow cytometric analysis of the drug's effect on cutaneous fibroblasts and keratinocytes.RESULTS: Siramesine caused a profound reduction in the total number of mast cells in both lesional and uninvolved psoriatic skin biopsies without affecting the gross morphology of the tissue. The drug reduced the density of IL-6- and IL-17-positive mast cells, and showed antiproliferative effects on epidermal keratinocytes but had no apparent cytotoxic effect on keratinocytes or dermal fibroblasts.CONCLUSIONS: Considering the pathophysiology of psoriasis, the effects of siramesine on cutaneous mast cells may prove favourable from the therapeutic aspect. The results encourage further studies to assess the usefulness of siramesine and other lysosomotropic agents in the treatment of cutaneous mastocytoses and inflammatory skin diseases aggravated by dermal mast cells.
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| 11. |
- Karlsson, Teresa, et al.
(author)
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Immunofluorescence localization of nuclear retinoid receptors in psoriasis versus normal human skin
- 2004
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In: Acta Dermato-Venereologica. - : Medical Journals Sweden AB. - 0001-5555 .- 1651-2057. ; 84:5, s. 363-369
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Journal article (peer-reviewed)abstract
- Psoriasis responds favourably to treatment with retinoids but the cellular pathways mediating these effects are poorly understood. Retinoids regulate keratinocyte proliferation and maturation via binding to nuclear retinoic acid receptors (mainly RARalpha and RARgamma) which form heterodimers with the 9-cis-RA receptor, RXRalpha. We have previously shown that mRNA expression of RARalpha and RXRalpha is down-regulated in psoriatic lesions as compared with non-lesional human skin. In the present study, we investigated the protein expression of RARalpha, RARgamma and RXRalpha in normal and psoriatic skin using indirect immunofluorescence analysis. Epidermal keratinocytes of normal and non-lesional psoriatic skin displayed similar nuclear localization of all three receptors; RARalpha was detected with decreasing intensity from basal to suprabasal layers, RARgamma showed the opposite trend, whereas RXRalpha was evenly expressed throughout the epidermis. In lesional psoriatic skin, however, all three receptor proteins showed a much higher staining intensity in the lower half of the epidermis; in particular, RARalpha immunoreactivity was low or even absent in the upper layers of epidermis. The results support the idea that psoriasis is associated with abnormal retinoid signalling in lesional epidermis.
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| 12. |
- Karlsson, Teresa, et al.
(author)
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Topical retinoic acid alters the expression of cellular retinoic acid-binding protein-I and cellular retinoic acid-binding protein-II in non-lesional but not lesional psoriatic skin
- 2002
-
In: Experimental dermatology. - : Wiley. - 0906-6705 .- 1600-0625. ; 11:2, s. 143-152
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Journal article (peer-reviewed)abstract
- Therapeutic retinoids have profound effects on psoriatic skin pathology but their interactions with various retinoid-binding proteins in lesional vs non-lesional skin have not been investigated. Using quantitative real-time PCR the mRNA expression of cellular retinol-binding protein I (CRBPI) and retinoic acid-binding protein I/II (CRABPI/CRABPII) was studied in psoriatic and healthy control (=normal) skin after 4 days of occlusive RA/vehicle treatment (n=6). Untreated psoriatic lesions showed a markedly elevated CRABPII/CRABPI ratio, while the CRBPI level was reduced in lesional and non-lesional skin as compared to normal skin. In RA-treated normal and non-lesional skin, the mRNA expression of CRBPI was unaltered while that of CRABPI and CRABPII was reduced by approximately 80% and increased approximately 5-fold, respectively, as compared to vehicle-treated skin. In contrast, lesional skin exposed to RA showed an almost 90% increase in CRBPI transcripts but unaltered expression of CRABPI and CRABPII, yet, the mRNA expression of several inflammatory mediators, e.g. inducible nitric oxide synthase, interferon-gamma and interleukin-1beta, was clearly reduced. Immunohistochemistry localized CRABPII to suprabasal keratinocytes in normal skin and revealed markedly elevated levels in lesional skin. RA treatment induced CRABPII protein expression in normal and non-lesional skin, to similar levels as in untreated lesions. The results indicate that the effects of RA differ in normal/non-lesional psoriatic skin and lesional skin. Whether the high expression of CRABPII in psoriatic skin lesions is due to increased amounts of endogenous retinoids in lesional skin or reflects an abnormal regulation of the CRABPII gene in psoriasis remains to be studied.
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| 13. |
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| 14. |
- Kindmark, Andreas, et al.
(author)
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Oral Isotretinoin Therapy in Severe Acne Induces Transient Suppression of Biochemical Markers of Bone Turnover and Calcium Homeostasis
- 1998
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In: Acta Dermato-Venereologica. - : Medical Journals Sweden AB. - 0001-5555 .- 1651-2057. ; 78:4, s. 266-269
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Journal article (peer-reviewed)abstract
- Although dietary vitamin A is required for normal growth and development, long-term or high-dose administration of vitamin A derivatives (retinoids) may produce a variety of skeletal side-effects in man. In this study we investigated the early effects of oral isotretinoin therapy on bone turnover and calcium homeostasis in eleven consecutive patients with nodulocystic acne. The effects on bone metabolism were correlated to radiological and bone mineral density measurements following drug therapy for six months. Markers of bone turnover, i.e. serum osteocalcin, the carboxyterminal propeptide of type I collagen, bone specific alkaline phosphatase, the carboxyterminal telopeptide of type I collagen, and urine levels of calcium and hydroxyproline decreased significantly within five days of treatment (p < 0.05). There was also a statistically significant decrease in serum calcium, with a minimum on day five, and a marked increase in serum parathyroid hormone (p < 0.05). With continued treatment, however, the abnormal levels of these markers returned to baseline values within 14 days. No significant roentgenological changes or effects on bone mineral density were found in response to the drug. The observed inhibitory effects of isotretinoin on bone turnover, despite elevated parathyroid hormone levels, indicates that the drug exerts a direct effect on bone tissue.
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| 15. |
- Lampinen, Maria, et al.
(author)
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Mefloquine causes selective mast cell apoptosis in cutaneous mastocytosis lesions by a secretory granule-mediated pathway
- 2022
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In: Experimental dermatology. - : John Wiley & Sons. - 0906-6705 .- 1600-0625. ; 31:11, s. 1729-1740
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Journal article (peer-reviewed)abstract
- Mastocytosis is a KIT-related myeloproliferative disease characterised by abnormal expansion of neoplastic mast cells (MC) in the skin or virtually any other organ system. The cutaneous form of adult-onset mastocytosis is almost invariably combined with indolent systemic involvement for which curative therapy is yet not available. Here we evaluated a concept of depleting cutaneous MCs in mastocytosis lesions ex vivo by targeting their secretory granules. Skin biopsies from mastocytosis patients were incubated with or without mefloquine, an antimalarial drug known to penetrate into acidic organelles such as MC secretory granules. Mefloquine reduced the number of dermal MCs without affecting keratinocyte proliferation or epidermal gross morphology at drug concentrations up to 40 mu M. Flow cytometric analysis of purified dermal MCs showed that mefloquine-induced cell death was mainly due to apoptosis and accompanied by caspase-3 activation. However, caspase inhibition provided only partial protection against mefloquine-induced cell death, indicating predominantly caspase-independent apoptosis. Further assessments revealed that mefloquine caused an elevation of granule pH and a corresponding decrease in cytosolic pH, suggesting drug-induced granule permeabilisation. Extensive damage to the MC secretory granules was confirmed by transmission electron microscopy analysis. Further, blockade of granule acidification or serine protease activity prior to mefloquine treatment protected MCs from apoptosis, indicating that granule acidity and granule-localised serine proteases play major roles in the execution of mefloquine-induced cell death. Altogether, these findings reveal that mefloquine induces selective apoptosis of MCs by targeting their secretory granules and suggest that the drug may potentially extend its range of medical applications.
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| 16. |
- Li, Dongqing, et al.
(author)
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Human skin long noncoding RNA WAKMAR1 regulates wound healing by enhancing keratinocyte migration
- 2019
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In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 116:19, s. 9443-9452
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Journal article (peer-reviewed)abstract
- An increasing number of studies reveal the importance of long noncoding RNAs (lncRNAs) in gene expression control underlying many physiological and pathological processes. However, their role in skin wound healing remains poorly understood. Our study focused on a skin-specific lncRNA, LOC105372576, whose expression was increased during physiological wound healing. In human nonhealing wounds, however, its level was significantly lower compared with normal wounds under reepithelialization. We characterized LOC105372576 as a nuclear-localized, RNAPII-transcribed, and polyadenylated lncRNA. In keratinocytes, its expression was induced by TGF-beta signaling. Knockdown of LOC105372576 and activation of its endogenous transcription, respectively, reduced and increased the motility of keratinocytes and reepithelialization of human ex vivo skin wounds. Therefore, LOC105372576 was termed "wound and keratinocyte migration-associated lncRNA 1" (WAKMAR1). Further study revealed that WAKMAR1 regulated a network of protein-coding genes important for cell migration, most of which were under the control of transcription factor E2F1. Mechanistically, WAKMAR1 enhanced E2F1 expression by interfering with E2F1 promoter methylation through the sequestration of DNA methyltransferases. Collectively, we have identified a lncRNA important for keratinocyte migration, whose deficiency may be involved in the pathogenesis of chronic wounds.
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| 17. |
- Li, Dongqing, et al.
(author)
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miR-19a/b and miR-20a promote wound healing by regulating the inflammatory response of keratinocytes
- 2021
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In: Journal of Investigative Dermatology. - : Elsevier. - 0022-202X .- 1523-1747. ; 141:3, s. 659-671
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Journal article (peer-reviewed)abstract
- Persistent and impaired inflammation impedes tissue healing and is characteristic of chronic wounds. A better understanding of the mechanisms controlling wound inflammation is needed. Here we show that in human wound-edge keratinocytes, the expression of miR-17, miR-18a, miR-19a, miR-19b, and miR-20a, which all belong to the miR-17∼92 cluster, is upregulated during wound repair. However, their levels are lower in chronic ulcers than acute wounds at the proliferative phase. Conditional knockout of miR-17∼92 in keratinocytes as well as injection of miR-19a/b and miR-20a antisense inhibitors into wound-edges enhanced inflammation and delayed wound closure in mice. In contrast, conditional overexpression of the miR-17∼92 cluster or miR-19b alone in mice keratinocytes accelerated wound closure in vivo. Mechanistically, miR-19a/b and miR-20a decreased TLR3-mediated NF-κB activation by targeting SHCBP1 and SEMA7A, respectively, reducing the production of inflammatory chemokines/cytokines by keratinocytes. Thus, as crucial regulators of wound inflammation, lack of miR-19a/b and miR-20a may contribute to sustained inflammation and impaired healing in chronic wounds. In line with this, we show that a combinatory treatment with miR-19b and miR-20a improved wound healing in a mouse model of type 2 diabetes.
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| 18. |
- Liu, Wei, et al.
(author)
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Biosynthesis and function of all-trans- and 9-cis retinoic acid in parathyroid cells
- 1996
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In: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 229:3, s. 922-929
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Journal article (peer-reviewed)abstract
- We demonstrate that cultured human and bovine parathyroid cells incubated with all-trans-[11,12-3H]-retinol convert this tracer into all-trans- and 9-cis-retinoic acid. By using RT-PCR, cellular retinol-binding protein type I (CRBP I), cellular retinoic acid binding protein I and II (CRABP I and II), retinoic acid receptors (RARs) alpha, beta and gamma, and 9-cis-retinoic acid receptor (RXR) alpha transcripts were detected in human parathyroid cDNA. CRBP I and CRABP I expression was confirmed by immunohistochemistry. Both 9-cis- and all-trans-RA were found to suppress parathyroid hormone (PTH) secretion from dispersed human adenomatous parathyroid cells, which was augmented by combined treatment with 1mM RA and 100 nM 1,25 (OH)2D3. The present data establish parathyroid gland as a target for retinoids and as a site of synthesis of the hormonal forms of vitamin A (retinol), all-trans- and 9-cis-retinoic acid.
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| 19. |
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| 20. |
- Löntz, Werner, et al.
(author)
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Increased mRNA expression of manganese superoxide dismutase in psoriasis skin lesions and in cultured human keratinocytes exposed to IL-1 beta and TNF-alpha
- 1995
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In: Free Radical Biology & Medicine. - 0891-5849 .- 1873-4596. ; 18:2, s. 349-355
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Journal article (peer-reviewed)abstract
- Because reactive oxygen species have been implicated in the pathogenesis of various hyperproliferative and inflammatory diseases, the mRNA expression of the antioxidant enzyme superoxide dismutase was studied in psoriatic skin tissue. By using reverse transcription-PCR we found similar expression of copper, zinc superoxide dismutase (CuZnSOD) in the involved vs. uninvolved psoriatic skin. In contrast, the level of the manganese superoxide dismutase (MnSOD) mRNA message was consistently higher in lesional psoriatic skin as compared to adjacent uninvolved skin and healthy control skin. Parallel investigation of those cytokines that are thought to be direct or indirect inducers of the MnSOD activity revealed an increased mRNA expression of IL-1 beta, TNF-alpha, and GM-CSF in lesional psoriatic skin. To study if these cytokines exert a direct effect on dismutase expression in epidermal cells, human keratinocytes in culture were challenged with IL-1 beta, TNF-alpha, and GM-CSF. It was found that IL-1 beta and TNF-alpha, but not GM-CSF, induced the mRNA expression of MnSOD, and an additive effect was demonstrated for the two former cytokines. Further, the expression of both CuZnSOD and MnSOD transcripts was similar in cultured keratinocytes maintained at low differentiation (low Ca2+ medium) and cells forced to terminal differentiation (by high Ca2+ medium). Our results indicate that the abnormal expression of MnSOD mRNA in lesional psoriatic skin is not directly linked to the pathologic state of keratinocyte differentiation in the skin. It seems more likely that the cutaneous overexpression of MnSOD in psoriatic epidermis represents a protective cellular response evoked by cytokines released from inflammatory cells invading the diseased skin.
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| 21. |
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| 22. |
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| 23. |
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| 24. |
- Nilsson, Kenneth, Docent, 1953-, et al.
(author)
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Impact of prolonged storage of clinical samples at 4 degrees C on the recovery of dermatophytes by culture or PCR analysis
- 2019
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In: Journal de Mycologie Médicale. - : MASSON EDITEUR. - 1156-5233 .- 1773-0449. ; 29:1, s. 1-6
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Journal article (peer-reviewed)abstract
- Dermatophytes are common pathogens in superficial mycoses that are routinely identified by culture or PCR analysis of freshly collected skin, nail or hair specimens. Although clinical samples are normally processed without delay, practical or research issues may necessitate sample storage until later analysis. However, the influence of extended sample storage on the ability to recover fungi by culture vs. PCR analysis has not been specifically studied. Here, a total of 172 dermatological samples collected from 2013-2015 were examined before and after refrigerated storage at 4 degrees C for 10.2-32.3 (mean 25.6) months. By culture, 35% of the dermatophyte-containing fresh samples remained positive at reexamination. At species level, only 19% of initially Trichophyton rubrum-positive samples yielded a positive result after refrigeration, whereas few samples containing Trichophyton violaceum, Microsporum canis or Microsporum audouinii remained culture-positive. Using PCR, 76% of dermatophyte DNA-positive fresh samples were still positive at re-analysis. Notably, 92% of the samples targeted by the T. rubrum DNA primer remained positive after storage. Hence, PCR analysis is more favourable than cultivation with regard to the detectability of dermatophytes in long-term refrigerated clinical samples.
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| 25. |
- Ovrén, Ellen, et al.
(author)
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Dermatophytosis : fluorostaining enhances speed and sensitivity in direct microscopy of skin, nail and hair specimens from dermatology outpatients
- 2016
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In: Mycoses. - : Wiley. - 0933-7407 .- 1439-0507. ; 59:7, s. 436-441
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Journal article (peer-reviewed)abstract
- Direct microscopy of keratinised specimens is a standard screening procedure that assists clinicians to differentiate true superficial mycoses from non-fungal disorders of the skin, nail and hair. Most clinical dermatologists use bright-field microscopy when searching for dermatophyte fungi in clinical samples while laboratory-based mycologists increasingly favour fluorescence microscopy in order to optimise visualisation of fungal elements. This study compared the validity and speediness of fluorescence microscopy vs. conventional light microscopy when screening for fungi in 206 dermatological samples from dermatology outpatients. Both senior dermatologist and a less experienced investigator (medical student) attained high and comparable levels of specificity (91.7-93.8%), positive predictive value (77.1-81.4%) and negative predictive value (83.7-89.9%) using either method. Fluorostaining with Blankophor prior to fluorescence microscopy increased the sensitivity by 22 +/- 1% as compared to light microscopy of unstained samples. For both investigators, the time required to identify fungal elements by the fluorescence-based technique was reduced by at least 50%, thus improving the performance of direct microscopy in the clinical setting.
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| 26. |
- Rollman, Ola, et al.
(author)
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Platelet derived growth factor (PDGF) responsive epidermis formed from human keratinocytes transduced with the PDGF beta receptor gene.
- 2003
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In: J Invest Dermatol. ; 120, s. 742-
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Journal article (peer-reviewed)abstract
- Platelet-derived growth factor is a major proliferative and migratory stimulus for connective tissue cells during the initiation of skin repair processes. In response to injury, locally produced platelet-derived growth factor is secreted by a diversity of cutaneous cell types whereas target activity is confined to cells of mesenchymal origin, e.g. dermal fibroblasts and smooth muscle cells. Although epidermal cells contribute to cutaneous platelet-derived growth factor activity by their ample capacity to secrete platelet-derived growth factor ligand, normal epidermal keratinocytes are not known to express any member of the platelet-derived growth factor receptor family. In order to study if epidermis may be genetically transformed to a platelet-derived growth factor sensitive compartment we aimed to introduce the gene encoding human platelet-derived growth factor receptor beta (PDGF beta R) into epidermal keratinocytes using a retrovirus-derived vector. Successful gene transfer to primary cells was confirmed by immunofluorescence staining, southern blotting, and ligand-induced receptor autophosphorylation. By culturing a mixture of PDGF beta R-transduced and unmodified keratinocytes at the air-liquid interface on devitalized dermis, we were able to establish a multilayered epithelium showing histologic similarities to that evolved from native keratinocytes or keratinocytes transduced with the reporter gene encoding enhanced green fluorescent protein. Receptor-modified epidermal tissue cultured for 6 days and examined by immunofluorescence microscopy was shown to contain PDGF beta R-expressing keratinocytes distributed in all layers of living epidermis. By continued tissue culture in serum-containing medium, the epidermis became increasingly cornified although receptor-positive cells were still observed within the viable basal compartment. Stimulation of PDGF beta R-transduced epidermis with recombinant platelet-derived growth factor BB had a mitogenic effect as reflected by an increased frequency of Ki-67 positive keratinocytes. The study demonstrates that transgene expression of human PDGF beta R can be achieved in epidermal keratinocytes by retroviral transduction, and that ligand activation of such gene-modified skin equivalent enhances cell proliferation. In perspective, viral PDGF beta R gene transfer to keratinocytes may be a useful approach in studies of receptor tyrosine kinase mediated skin repair and epithelialization.
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| 27. |
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| 28. |
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| 29. |
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| 30. |
- Rönnberg, Elin, et al.
(author)
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Granzyme H Is a Novel Protease Expressed by Human Mast Cells
- 2014
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In: International Archives of Allergy and Immunology. - : S. Karger AG. - 1018-2438 .- 1423-0097. ; 165:1, s. 68-74
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Journal article (peer-reviewed)abstract
- Background: Many of the functions attributed to mast cells depend on the various pro-inflammatory mediators that are secreted upon mast cell activation. These include a panel of mast cell-specific proteases. In addition, recent studies have indicated that murine mast cells also express granzyme D, a protease previously thought to be confined to cytotoxic lymphocytes. Here, we address the human relevance of the latter findings by investigating whether human mast cells express granzyme H, the granzyme that may represent the functional counterpart to murine granzyme D. Methods: Cord blood-derived mast cells, LAD2 cells and skin mast cells in situ were evaluated for their expression of granzymes using quantitative PCR, Western blot analysis and immunostaining. Mast cells were activated by either calcium ionophore stimulation or IgE receptor cross-linking. Results: Cord blood-derived mast cells and LAD2 cells were shown to express granzyme H and B mRNA, while granzyme A, K and M expression was undetectable. Mast cell activation by either calcium ionophore or IgE receptor cross-linking caused down-regulated expression of granzyme H. In contrast, granzyme B expression was up-regulated by the same stimuli. Granzyme H expression was also confirmed at the protein level, as shown by both Western blot analysis and confocal microscopy. Further, we show that granzyme H is expressed by human skin mast cells in situ. Conclusions: The present findings implicate granzyme H as a novel protease expressed by human mast cells and support earlier findings obtained in natural killer cells suggesting that granzymes B and H are reciprocally regulated.
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| 31. |
- Sirsjö, Allan, et al.
(author)
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Increased expression of inducible nitric oxide synthase in psoriatic skin and cytokine-stimulated cultured keratinocytes
- 1996
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In: British Journal of Dermatology. - 0007-0963 .- 1365-2133. ; 134:4, s. 643-648
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Journal article (peer-reviewed)abstract
- Since nitric oxide (NO) has been implicated in the pathogenesis of various hyperproliferative and inflammatory diseases, the mRNA expression of constitutive nitric oxide synthase (cNOS) and inducible nitric oxide synthase (iNOS) were investigated in psoriatic skin by reverse transcriptase coupled to the polymerase chain reaction (PCR). The study showed that the mRNA expression of brain nitric oxide synthase (bNOS), one of two isoforms of cNOS, was weak in both psoriatic plaques lesions and uninvolved skin, while mRNA transcripts for the second isoform, endothelial nitric oxide synthase (eNOS), were not detectable using the present method. In contrast, the mRNA expression of iNOS was markedly increased in lesional skin as compared to uninvolved skin. Cultured human keratinocytes exposed to a combination of interleukin-1 beta (IL-1 beta) and tumour necrosis factor-alpha (TNF-alpha) for 4 h, showed strong gene expression of iNOS, while in 24 h, the expression had returned to baseline expression. In summary, the study demonstrates that mRNA for the inducible form of NOS is over-expressed in psoriatic lesions. The cause of this may be the local presence of inflammatory cytokines. These findings imply that iNOS may play an important part in local regulation of NO synthesis in psoriasis and other inflammatory dermatoses.
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| 32. |
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| 33. |
- Skoog, Tiina, et al.
(author)
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Matrix metalloproteinase-21 expression is associated with keratinocyte differentiation and upregulated by retinoic acid in HaCaT cells
- 2009
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In: Journal of Investigative Dermatology. - : Elsevier BV. - 0022-202X .- 1523-1747. ; 129:1, s. 119-30
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Journal article (peer-reviewed)abstract
- In the skin, expression of several matrix metalloproteinases (MMPs) occurs in response to tissue injury, tumorigenesis, angiogenesis, apoptosis, and inflammation. The recently cloned MMP-21 has been implicated in skin development and various epithelial cancers. In this study, we found that it is also expressed by differentiated keratinocytes (KCs) in various benign skin disorders, in which it was not associated with KC apoptosis or proliferation, and in organotypic cultures. Furthermore, MMP-21 was induced in keratinocytes in association with increased calcium and presence of the differentiation marker filaggrin. In stably transfected A431 and HEK293 cell lines, MMP-21 increased invasion of cells but did not associate with increased apoptosis, proliferation, or epithelial-to-mesenchymal transition. Of various agents tested in HaCaT cell cultures, only retinoic acid (10(-6) M) and staurosporine (2.5 x 10(-8) M) upregulated MMP-21 mRNA and protein expression, whereas tumor promoters, hormones, or dexamethasone were without effect. Our results suggest that MMP-21 may be an important protease in the terminal differentiation of keratinocytes.
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| 34. |
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| 35. |
- Tiala, Inkeri, et al.
(author)
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The PSORS1 locus gene CCHCR1 affects keratinocyte proliferation in transgenic mice
- 2008
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In: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 17:7, s. 1043-1051
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Journal article (peer-reviewed)abstract
- The CCHCR1 gene (Coiled-Coil alpha-Helical Rod protein 1) within the major psoriasis susceptibility locus PSORS1 is a plausible candidate gene for the risk effect. We have previously generated transgenic mice overexpressing either the psoriasis-associated risk allele CCHCR1*WWCC or the normal allele of CCHCR1. All transgenic CCHCR1 mice appeared phenotypically normal, but exhibited altered expression of genes relevant to the pathogenesis of psoriasis, including upregulation of hyperproliferation markers keratins 6, 16 and 17. Here, we challenged the skin of CCHCR1 transgenic mice with wounding or 12-O-tetradecanoyl-13-acetate (TPA), treatments able to induce epidermal hyperplasia and proliferation that both are hallmarks of psoriasis. These experiments revealed that CCHCR1 regulates keratinocyte proliferation. Early wound healing on days 1 and 4 was delayed, and TPA-induced epidermal hyperproliferation was less pronounced in mice with the CCHCR1*WWCC risk allele than in mice with the normal allele or in wild-type animals. Finally, we demonstrated that overexpression of CCHCR1 affects basal keratinocyte proliferation in mice; CCHCR1*WWCC mice had less proliferating keratinocytes than the non-risk allele mice. Similarly, keratinocytes isolated from risk allele mice proliferated more slowly in culture than wild-type cells when measured by BrdU labeling and ELISA. Our data show that CCHCR1 may function as a negative regulator of keratinocyte proliferation. Thus, aberrant function of CCHCR1 may lead to abnormal keratinocyte proliferation which is a key feature of psoriatic epidermis.
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| 36. |
- Törmä, Hans, et al.
(author)
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Decreased mRNA Levels of Retinoic Acid Receptor alpha, Retinoid X Receptor alpha and Thyroid Hormone Receptor alpha in Lesional Psoriatic Skin
- 2000
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In: Acta Dermato-Venereologica. - : Medical Journals Sweden AB. - 0001-5555 .- 1651-2057. ; 80:1, s. 4-9
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Journal article (peer-reviewed)abstract
- Retinoic acid, vitamin D3 and triiodothyronine regulate keratinocyte proliferation and differentiation--processes that are disturbed in psoriatic skin--via binding to nuclear receptors for retinoic acid (RAR-alpha,-gamma), vitamin D3 (VDR), thyroid hormone (TR-alpha,-beta) plus the common heterodimer partners, the 9-cis-retinoic acid receptors (RXR-alpha,-beta). By using a new quantitative real-time polymerase chain reaction assay, the expression of these receptors and three housekeeping genes (cyclophilin, GAPDH and beta-actin) was studied in psoriatic skin. The expression of housekeeping genes was consistently 2.7-4.3 times higher in lesional than in non-lesional skin. When the beta-actin expression was used to normalize the receptor mRNA values, the RARalpha, RXRalpha and TRalpha transcripts were found to be 58-75% lower in lesional vs. non-lesional skin and the RXRalpha:RARgamma ratio was reduced from 3.2 to 1.5. Topical treatment for 4 days with 0.025% all-trans-retinoic acid or calcipotriol under occlusion did not normalize the altered mRNA expression of RARs, RXR and VDR in lesional skin. The results suggest that retinoid and thyroid hormone signalling is abnormal in lesional psoriatic skin, but how this relates to the pathogenesis of the disease is still unclear.
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| 37. |
- Törmä, Hans, et al.
(author)
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The vitamin A metabolism and expression of retinoid-binding proteins differ in HaCaT cells and normal human keratinocytes
- 1999
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In: Archives of Dermatological Research. - : Springer Science and Business Media LLC. - 0340-3696 .- 1432-069X. ; 291:6, s. 339-345
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Journal article (peer-reviewed)abstract
- HaCaT keratinocytes differ from normal human epidermal keratinocytes (HEK) by constitutive expression of differentiation markers which are normally suppressed by vitamin A. In search of an explanation for this discrepancy we compared the vitamin A content, the expression of retinoid-binding proteins, and the vitamin A metabolism in the two cell types. The concentrations of retinol and 3,4-didehydroretinol in cultured HaCaT cells were less than one-fifth those in HEK, and the content of fatty acyl esters was even lower. Similarly, the concentrations of cellular retinol-binding protein and cellular retinoic acid-binding protein (CRBPI and CRABPII, respectively) were 10-30 times lower in HaCaT cells than in HEK corresponding to a reduced mRNA expression of these proteins. Unexpectedly, HaCaT cells expressed RARbeta in addition to RARalpha, RARgamma and RXRalpha, which are nuclear receptors normally found in HEK. Radioactive retinol added to the culture medium appeared only transiently in HaCaT cells, and pulse labeling confirmed a defective cellular retention of retinyl esters. After 24 h of incubation with [3H]retinol, cell-associated radioactivity corresponding to retinol, 3,4-didehydroretinol, all-trans-retinoic acid and 3,4-didehydroretinoic acid was found in both HaCaT cells and HEK. [3H]Retinoic acid showed a more rapid metabolism to 4-hydroxy/4-keto-retinoic acid in HaCaT cells than in HEK, which could be explained by a higher expression of cytochrome p450RAI in the former cells. In conclusion, the abnormal uptake of vitamin A and low levels of retinoid binding proteins in HaCaT cells, linked with an aberrant metabolism of retinol, may help to explain why these cells differentiate also in the presence of retinoids.
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| 38. |
- Törmä, Hans, et al.
(author)
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Vitamin D analogs affect the uptake and metabolism of retinol by human epidermal keratinocytes in culture
- 1996
-
In: Journal of Investigative Dermatology Symposium Proceedings. - 1087-0024 .- 1529-1774. ; 1:1, s. 49-53
-
Journal article (peer-reviewed)abstract
- Human epidermis utilizes retinol as precursor for local production of a range of bioactive vitamin A metabolites including 3,4-didehydroretinol, retinoic acid, and 3,4-didehydroretinoic acid. These endogenously formed retinoids bind to nuclear retinoic acid receptors (RARs), thereby altering gene transcription. Because 9-cis-retinoic acid receptors (RXRs) form heterodimers both with RARs and the vitamin D3 receptor (VDR), it is plausible that vitamin D3 may affect retinol metabolism if altered transcription is involved in the regulation of vitamin A-metabolizing enzymes. To investigate the potential effect of vitamin D on retinol metabolism in human skin keratinocytes, HaCaT cells were preincubated with various vitamin D3-analogs at 10(-7)M for 24 h followed by the addition of [3H]retinol for another 24 h period. The uptake and metabolism of the radioactive tracer was monitored by HPLC-radiochromatography. It was found that all synthetic vitamin D-analogs tested (MC903, KH1060, EB1089, and EB1213) reduced the amount of cell-associated [3H]retinoid activity by 35-50% as compared to the vehicle. More specifically, the appearance of the parent substrate and two of its main metabolites, e.g., 3,4-didehydroretinol (ddROH) and 3,4-didehydroretinoic acid (ddRA), was inhibited by the synthetic vitamin D-analogs. The effects on retinol metabolism were not potentiated by coincubation of cells with vitamin D-analogs plus retinoic acid (RA) or 9-cis-RA. This study demonstrates that synthetic vitamin D3 interferes with both the uptake and the metabolism of retinol by human epidermal keratinocytes. Whether the effects are due to direct inhibition of cellular retinol uptake and metabolism or involve VDR-mediated transcriptional alteration of vitamin A metabolizing enzymes remains to be clarified.
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| 39. |
- Vahlquist, Anders, et al.
(author)
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Increased concentrations of 3,4-didehydroretinol and retinoic acid-binding protein (CRABPII) in human squamous cell carcinoma and keratoacanthoma but not in basal cell carcinoma of the skin
- 1996
-
In: Journal of Investigative Dermatology. - : Elsevier BV. - 0022-202X .- 1523-1747. ; 106:5, s. 1070-1074
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Journal article (peer-reviewed)abstract
- Retinoids are biologic response modifiers that are present in normal skin and may possibly be perturbed in carcinogenesis. To examine this possibility in human skin, we analyzed vitamin A and cytosolic retinoid binding proteins (cellular retinol binding protein and cellular retinoic acid binding protein [CRABP]) in a total of 38 non-melanoma skin tumors and 25 healthy skin samples using high performance liquid chromatography, radioligand electrophoresis, and reverse transcriptase-polymerase chain reaction. The mean +/- SEM retinol concentration was normal in basal cell carcinoma (0.60 +/- 0.10 microM) and seborrheic keratosis (0.47 +/- 0.07 microM), but increased in keratoacanthoma (1.60 +/- 0.41 microM) and squamous cell carcinoma (1.17 +/- 0.28 microM) (p < 0.05 for both). Also, the concentrations of 3,4-didehydroretinol, a major vitamin A metabolite produced in human skin, were markedly elevated (6-7 times normal) in keratoacanthoma and squamous cell cancer. All types of tumors showed moderately increased levels of cellular retinol binding protein. In addition, keratoacanthoma and squamous cell cancer showed markedly increased levels (6-7 times normal) of CRABPII protein. Transcriptional activity of the CRABPII gene was demonstrated in both normal and neoplastic epidermis, but clear CRABPI mRNA expression was found only in basal cell carcinoma. The data indicate that characteristic perturbations of the vitamin A and retinoid binding protein levels occur in squamous cell-derived skin tumors, but whether these reflect intrinsic errors in retinoid metabolism or are secondary to abnormal cellular differentiation is unknown.
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| 40. |
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| 41. |
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| 42. |
- Vraila, Marianthi, et al.
(author)
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Monensin induces secretory granule-mediated cell death in eosinophils
- 2023
-
In: Journal of Allergy and Clinical Immunology. - : Elsevier. - 0091-6749 .- 1097-6825. ; 152:5
-
Journal article (peer-reviewed)abstract
- Background: Eosinophils contribute to the pathology of several types of disorders, in particular of allergic nature, and strategies to limit their actions are therefore warranted.Objective: We sought to evaluate the possibility of targeting the acidic, lysosome-like eosinophil granules as a potential means of inducing eosinophil cell death.Methods: To this end, we used monensin, an ionophoric drug that has previously been shown to permeabilize the secretory granules of mast cells, thereby inducing cell death.Results: Our findings reveal that monensin induces cell death in human eosinophils, whereas neutrophils were less affected. Blockade of granule acidification reduced the effect of monensin on the eosinophils, demonstrating that granule acidity is an important factor in the mechanism of cell death. Furthermore, monensin caused an elevation of the granule pH, which was accompanied by a decrease of the cytosolic pH, hence indicating that monensin caused leakage of acidic contents from the granules into the cytosol. In agreement with a granule-targeting mechanism, transmission electron microscopy analysis revealed that monensin caused extensive morphological alterations of the eosinophil granules, as manifested by a marked loss of electron density. Eosinophil cell death in response to monensin was caspase-independent, but dependent on granzyme B, a pro-apoptotic serine protease known to be expressed by eosinophils.Conclusions: We conclude that monensin causes cell death of human eosinophils through a granule-mediated mechanism dependent on granzyme B.
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| 43. |
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| 44. |
- Wu, Jianmin, et al.
(author)
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MicroRNA-34 Family Enhances Wound Inflammation by Targeting LGR4
- 2020
-
In: Journal of Investigative Dermatology. - : Elsevier. - 0022-202X .- 1523-1747. ; 140:2, s. 465-476
-
Journal article (peer-reviewed)abstract
- Venous ulcers are the most common type of human chronic nonhealing wounds and are stalled in a constant and excessive inflammatory state. The molecular mechanisms underlying the chronic wound inflammation remain elusive. Moreover, little is known about the role of regulatory RNAs, such as microRNAs, in the pathogenesis of venous ulcers. We found that both microRNA (miR)-34a and miR-34c were upregulated in the wound-edge epidermal keratinocytes of venous ulcers compared with normal wounds or the skin. In keratinocytes, miR-34a and miR-34c promoted inflammatory chemokine and cytokine production. In wounds of wild-type mice, miR-34a-mimic treatment enhanced inflammation and delayed healing. To further explore how miR-34 functions, LGR4 was identified as a direct target mediating the proinflammatory function of miR-34a and miR-34c. Interestingly, impaired wound closure with enhanced inflammation was also observed in Lgr4 knockout mice. Mechanistically, the miR-34-LGR4 axis regulated GSK-3β-induced p65 serine 468 phosphorylation, changing the activity of the NF-κB signaling pathway. Collectively, the miR-34-LGR4 axis was shown to regulate keratinocyte inflammatory response, the deregulation of which may play a pathological role in venous ulcers.
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| 45. |
- Zhao, Xinran, 1995-, et al.
(author)
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Mast cell chymase affects the functional properties of primary human airway fibroblasts : Implications for asthma
- 2022
-
In: Journal of Allergy and Clinical Immunology. - : Elsevier. - 0091-6749 .- 1097-6825. ; 149:2, s. 718-727
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Mast cells (MCs) have a profound impact on allergic asthma. Under such conditions, MCs undergo degranulation, resulting in the release of exceptionally large amounts of MC-restricted proteases. However, the role of these proteases in asthma is only partially understood.OBJECTIVES: We sought to test our hypothesis that MC proteases can influence the functionality of human lung fibroblasts (HLFs).METHODS: Primary HLFs were treated with MC chymase or tryptase, followed by assessment of parameters related to fibroblast function.RESULTS: HLFs underwent major morphologic changes in response to chymase, showing signs of cellular contraction, but were refractory to tryptase. However, no effects of chymase on HLF viability or proliferation were seen. Chymase, but not tryptase, had a major impact on the output of extracellular matrix-associated compounds from the HLFs, including degradation of fibronectin and collagen-1, and activation of pro-matrix metalloprotease 2. Further, chymase induced the release of various chemotactic factors from HLFs. In line with this, conditioned medium from chymase-treated HLFs showed chemotactic activity on neutrophils. Transcriptome analysis revealed that chymase induced a proinflammatory gene transcription profile in HLFs, whereas tryptase had minimal effects.CONCLUSIONS: Chymase, but not tryptase, has a major impact on the phenotype of primary airway fibroblasts by modifying their output of extracellular matrix components and by inducing a proinflammatory phenotype.
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