| 1. |
- Belsõ, Nóra, et al.
(författare)
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Differential expression of D-type cyclins in HaCaT keratinocytes and in psoriasis.
- 2008
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Ingår i: Journal of Investigative Dermatology. - : Elsevier BV. - 0022-202X .- 1523-1747. ; 128:3, s. 634-42
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we show that the G0-G1/S phase of HaCaT keratinocyte cell cycle is characterized by D1-type cyclin expression, whereas during the repeated rapid turnover of highly proliferating cells, the expression of cyclins D2 and D3 dominates. Knocking down cyclin D1 mRNA resulted in no change of cell proliferation and morphology, indicating that D2 and D3 cyclins could substitute for D1 in driving the cell cycle. Increased numbers of cyclin D1-expressing keratinocytes were found in the basal layers of the lesional psoriatic epidermis compared to both normal and non-lesional epidermis without increased expression of cyclin D1 mRNA, suggesting a possible dysfunction in the degradation of cyclin D1 protein. We also detected a significant increase in cyclin D2 and D3 mRNA expressions in psoriatic epidermis compared to normal epidermis with no difference in protein expressions. Blocking alpha5-integrin function by a neutralizing antibody in HaCaT keratinocytes downregulated the expression of cyclin D1 mRNA without affecting the expressions of cyclin D2 and D3 indicating a regulatory role for alpha5-integrin in the expression of cyclin D1. Our data suggest a possible role for D-type cyclins in the excessive basal-cell proliferation and perturbed keratinocyte differentiation in the psoriatic epidermis.
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| 2. |
- Bergman, Petra, et al.
(författare)
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Next-generation sequencing identifies microRNAs that associate with pathogenic autoimmune neuroinflammation in rats.
- 2013
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 190:8, s. 4066-75
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Tidskriftsartikel (refereegranskat)abstract
- MicroRNAs (miRNAs) are known to regulate most biological processes and have been found dysregulated in a variety of diseases, including multiple sclerosis (MS). In this study, we characterized miRNAs that associate with susceptibility to develop experimental autoimmune encephalomyelitis (EAE) in rats, a well-established animal model of MS. Using Illumina next-generation sequencing, we detected 544 miRNAs in the lymph nodes of EAE-susceptible Dark Agouti and EAE-resistant Piebald Virol Glaxo rats during immune activation. Forty-three miRNAs were found differentially expressed between the two strains, with 81% (35 out of 43) showing higher expression in the susceptible strain. Only 33% of tested miRNAs displayed differential expression in naive lymph nodes, suggesting that a majority of regulated miRNAs are EAE dependent. Further investigation of a selected six miRNAs indicates differences in cellular source and kinetics of expression. Several of the miRNAs, including miR-146a, miR-21, miR-181a, miR-223, and let-7, have previously been implicated in immune system regulation. Moreover, 77% (33 out of 43) of the miRNAs were associated with MS and other autoimmune diseases. Target genes likely regulated by the miRNAs were identified using computational predictions combined with whole-genome expression data. Differentially expressed miRNAs and their targets involve functions important for MS and EAE, such as immune cell migration through targeting genes like Cxcr3 and cellular maintenance and signaling by regulation of Prkcd and Stat1. In addition, we demonstrated that these three genes are direct targets of miR-181a. Our study highlights the impact of multiple miRNAs, displaying diverse kinetics and cellular sources, on development of pathogenic autoimmune inflammation.
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| 3. |
- Chamorro, Clara I, et al.
(författare)
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The human antimicrobial peptide LL-37 suppresses apoptosis in keratinocytes.
- 2009
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Ingår i: Journal of Investigative Dermatology. - : Elsevier BV. - 0022-202X .- 1523-1747. ; 129:4, s. 937-44
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Tidskriftsartikel (refereegranskat)abstract
- The human cathelicidin antimicrobial peptide LL-37 is involved in various aspects of skin biology, including protection against infection, wound healing, and also in psoriasis. The tight regulation of apoptosis is critical in tissue repair and its deregulation is a part of the psoriasis phenotype. Despite being involved in cell death of several cell types, virtually nothing is known about the function of LL-37 in keratinocyte apoptosis. Here we report that LL-37 peptide protects primary human keratinocytes and HaCaT cells from apoptosis induced by the topoisomerase I inhibitor camptothecin (CAM). In particular, pretreatment with LL-37 significantly decreased caspase-3 activity after CAM-treatment. Expression profiling of keratinocytes treated with LL-37 identified the upregulation of cyclooxygenase-2 (COX-2) expression, a gene implicated in protection from apoptosis. In addition to inducing COX-2 expression, LL-37 stimulated the production of its product, prostaglandin E-2 (PGE-2). Moreover, LL-37 induced the expression of inhibitor of apoptosis-2 (IAP-2), implicated in the COX-2/PGE-2 antiapoptotic pathway. Pretreatment with a selective COX-2 inhibitor abolished the antiapoptotic effect of LL-37 and reduced IAP-2 expression implicating that the antiapoptotic effect of LL-37 in keratinocytes is mediated by a COX-2-dependent mechanism involving IAP-2. Thus, overexpression of LL-37 may contribute to reduced keratinocyte apoptosis in conditions such as psoriasis.
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| 4. |
- Das Mahapatra, Kunal, et al.
(författare)
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A comprehensive analysis of coding and non-coding transcriptomic changes in cutaneous squamous cell carcinoma
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Cutaneous Squamous Cell Carcinoma (cSCC) is the most common and fastest-increasing cancer with metastatic potential. Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) are novel regulators of gene expression. To identify mRNAs, lncRNAs and circRNAs, which can be involved in cSCC, RNA-seq was performed on nine cSCCs and seven healthy skin samples. Representative transcripts were validated by NanoString nCounter assays using an extended cohort, which also included samples from pre-cancerous skin lesions (actinic keratosis). 5,352 protein-coding genes, 908 lncRNAs and 55 circular RNAs were identified to be differentially expressed in cSCC. Targets of 519 transcription factors were enriched among differentially expressed genes, 105 of which displayed altered level in cSCCs, including fundamental regulators of skin development (MYC, RELA, ETS1, TP63). Pathways related to cell cycle, apoptosis, inflammation and epidermal differentiation were enriched. In addition to known oncogenic lncRNAs (PVT1, LUCAT1, CASC9), a set of skin-specific lncRNAs were were identified to be dysregulated. A global downregulation of circRNAs was observed in cSCC, and novel skin-enriched circRNAs, circ_IFFO2 and circ_POF1B, were identified and validated. In conclusion, a reference set of coding and non-coding transcripts were identified in cSCC, which may become potential therapeutic targets or biomarkers.
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| 5. |
- Fekete, Tünde, et al.
(författare)
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Constraints for monocyte-derived dendritic cell functions under inflammatory conditions.
- 2012
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Ingår i: European Journal of Immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 42:2, s. 458-69
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Tidskriftsartikel (refereegranskat)abstract
- The activation of TLRs expressed by macrophages or DCs, in the long run, leads to persistently impaired functionality. TLR signals activate a wide range of negative feedback mechanisms; it is not known, however, which of these can lead to long-lasting tolerance for further stimulatory signals. In addition, it is not yet understood how the functionality of monocyte-derived DCs (MoDCs) is influenced in inflamed tissues by the continuous presence of stimulatory signals during their differentiation. Here we studied the role of a wide range of DC-inhibitory mechanisms in a simple and robust model of MoDC inactivation induced by early TLR signals during differentiation. We show that the activation-induced suppressor of cytokine signaling 1 (SOCS1), IL-10, STAT3, miR146a and CD150 (SLAM) molecules possessed short-term inhibitory effects on cytokine production but did not induce persistent DC inactivation. On the contrary, the LPS-induced IRAK-1 downregulation could alone lead to persistent MoDC inactivation. Studying cellular functions in line with the activation-induced negative feedback mechanisms, we show that early activation of developing MoDCs allowed only a transient cytokine production that was followed by the downregulation of effector functions and the preservation of a tissue-resident non-migratory phenotype.
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| 6. |
- Garaczi, Edina, et al.
(författare)
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Negative regulatory effect of histamine in DNFB-induced contact hypersensitivity.
- 2004
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Ingår i: International Immunology. - : Oxford University Press (OUP). - 0953-8178 .- 1460-2377. ; 16:12, s. 1781-8
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Tidskriftsartikel (refereegranskat)abstract
- Histamine plays an important role in the regulation of various immunological functions. To evaluate the role of histamine in contact hypersensitivity, contact dermatitis was induced with dinitrofluorobenzene (DNFB) in histidine decarboxylase knockout (HDC-/-) histamine-deficient and wild-type mice. The DNFB-induced increase of the ear thickness was significantly higher in HDC-/- mice than in wild-type mice. Using flow cytometry, significantly lower percentages of CD4+ Th and CD8+ Tc cells, and significantly higher percentages of CD45R+ B cells were observed in the regional lymph nodes in HDC-/- mice than in wild-type mice. In the ear specimens of both groups, the majority of the infiltrating cells were neutrophils and macrophages at 24 and 48 h after challenge. Using immunohistochemistry, we observed significantly more CD45+ leukocytes in HDC-/- mice than in wild-type mice. The expression of Th1 (IL-2, IFN-gamma, TNF-alpha) and Th2 (IL-4) mRNAs was examined by quantitative real time RT-PCR in the ear samples. The levels of Th1 cytokine mRNAs both at 24 and 48 h after challenge and IL-4 mRNA at 48 h showed a significantly higher increase in HDC-/- mice than in wild-type mice. These results suggest that histamine plays a negative immunoregulatory role in DNFB-induced contact hypersensitivity.
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| 7. |
- Gastaldi, Cécile, et al.
(författare)
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miR-193b/365a cluster controls progression of epidermal squamous cell carcinoma.
- 2014
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Ingår i: Carcinogenesis. - : Oxford University Press (OUP). - 0143-3334 .- 1460-2180. ; 35:5, s. 1110-20
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Tidskriftsartikel (refereegranskat)abstract
- Incidence of cutaneous squamous cell carcinomas (cSCCs) constantly increases in the Caucasian population. Developing preferentially on precancerous lesions such as actinic keratoses due to chronic sunlight exposure, cSCCs result from the malignant transformation of keratinocytes. Although a resection of the primary tumor is usually curative, a subset of aggressive cSCCs shows a high risk of recurrence and metastases. The characterization of the molecular dysfunctions involved in cSCC development should help to identify new relevant targets against these aggressive cSCCs. In that context, we have used small RNA sequencing to identify 100 microRNAs (miRNAs) whose expression was altered during chemically induced mouse skin tumorigenesis. The decreased expression of the miR-193b/365a cluster during tumor progression suggests a tumor suppressor role. Ectopic expression of these miRNAs in tumor cells indeed inhibited their proliferation, clonogenic potential and migration, which were stimulated in normal keratinocytes when these miRNAs were blocked with antisense oligonucleotides. A combination of in silico predictions and transcriptome analyses identified several target genes of interest. We validated KRAS and MAX as direct targets of miR-193b and miR-365a. Repression of these targets using siRNAs mimicked the effects of miR-193b and miR-365a, suggesting that these genes might mediate, at least in part, the tumor-suppressive action of these miRNAs.
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| 8. |
- Gombert, Michael, et al.
(författare)
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CCL1-CCR8 interactions : an axis mediating the recruitment of T cells and Langerhans-type dendritic cells to sites of atopic skin inflammation.
- 2005
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 174:8, s. 5082-91
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Tidskriftsartikel (refereegranskat)abstract
- Atopic dermatitis represents a chronically relapsing skin disease with a steadily increasing prevalence of 10-20% in children. Skin-infiltrating T cells, dendritic cells (DC), and mast cells are thought to play a crucial role in its pathogenesis. We report that the expression of the CC chemokine CCL1 (I-309) is significantly and selectively up-regulated in atopic dermatitis in comparison to psoriasis, cutaneous lupus erythematosus, or normal skin. CCL1 serum levels of atopic dermatitis patients are significantly higher than levels in healthy individuals. DC, mast cells, and dermal endothelial cells are abundant sources of CCL1 during atopic skin inflammation and allergen challenge, and Staphylococcus aureus-derived products induce its production. In vitro, binding and cross-linking of IgE on mast cells resulted in a significant up-regulation of this inflammatory chemokine. Its specific receptor, CCR8, is expressed on a small subset of circulating T cells and is abundantly expressed on interstitial DC, Langerhans cells generated in vitro, and their monocytic precursors. Although DC maintain their CCR8+ status during maturation, brief activation of circulating T cells recruits CCR8 from intracytoplamic stores to the cell surface. Moreover, the inflammatory and atopy-associated chemokine CCL1 synergizes with the homeostatic chemokine CXCL12 (SDF-1alpha) resulting in the recruitment of T cell and Langerhans cell-like DC. Taken together, these findings suggest that the axis CCL1-CCR8 links adaptive and innate immune functions that play a role in the initiation and amplification of atopic skin inflammation.
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| 9. |
- Hippe, Andreas, et al.
(författare)
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EGFR/Ras-induced CCL20 production modulates the tumour microenvironment.
- 2020
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 123:6, s. 942-954
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The activation of the EGFR/Ras-signalling pathway in tumour cells induces a distinct chemokine repertoire, which in turn modulates the tumour microenvironment.METHODS: The effects of EGFR/Ras on the expression and translation of CCL20 were analysed in a large set of epithelial cancer cell lines and tumour tissues by RT-qPCR and ELISA in vitro. CCL20 production was verified by immunohistochemistry in different tumour tissues and correlated with clinical data. The effects of CCL20 on endothelial cell migration and tumour-associated vascularisation were comprehensively analysed with chemotaxis assays in vitro and in CCR6-deficient mice in vivo.RESULTS: Tumours facilitate progression by the EGFR/Ras-induced production of CCL20. Expression of the chemokine CCL20 in tumours correlates with advanced tumour stage, increased lymph node metastasis and decreased survival in patients. Microvascular endothelial cells abundantly express the specific CCL20 receptor CCR6. CCR6 signalling in endothelial cells induces angiogenesis. CCR6-deficient mice show significantly decreased tumour growth and tumour-associated vascularisation. The observed phenotype is dependent on CCR6 deficiency in stromal cells but not within the immune system.CONCLUSION: We propose that the chemokine axis CCL20-CCR6 represents a novel and promising target to interfere with the tumour microenvironment, and opens an innovative multimodal strategy for cancer therapy.
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| 10. |
- Hoffmann, Thomas K, et al.
(författare)
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A novel mechanism for anti-EGFR antibody action involves chemokine-mediated leukocyte infiltration.
- 2009
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 124:11, s. 2589-96
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Tidskriftsartikel (refereegranskat)abstract
- Overexpression of the epidermal growth factor receptor (EGFR) is a hallmark of squamous cell carcinoma of the head and neck (SCCHN). Monoclonal antibodies (mAbs) against EGFR are currently used for therapy of recurrent or metastatic disease; however, their mode of action is not completely understood. To investigate the immunological effects of anti-EGFR mAb, we generated a three-dimensional spheroid model of EGFR-expressing SCCHN and used this model to study the effect of anti-EGFR mAb on leukocyte migration toward tumors. Pretreatment with the blocking anti-EGFR mAb EMD 72000, its F(ab')2 fragments or an EGFR tyrosine kinase inhibitor led to substantially increased leukocyte infiltration into EGFR overexpressing tumor spheroids, but not into those with low EGFR expression. Nonblocking anti-EGFR mAb or fibroblast-specific mAb did not affect leukocyte infiltration, suggesting that the observed increase in leukocyte infiltration depends on interference with EGFR activation. Using a human cytokine macroarray, we demonstrated that the blockade of EGFR by anti-EGFR mAb in EGFR-overexpressing SCCHN cells leads to differential expression of several cytokines and chemokines, including the chemokine MCP-1/CCL-2. The significant upregulation of MCP-1/CCL2 on exposure to anti-EGFR mAb was confirmed by quantitative PCR and enzyme-linked immunospot analyses. Moreover, blocking anti-MCP-1 antibody inhibited leukocyte migration toward tumor cells induced by anti-EGFR mAb, pointing to an important role of MCP-1/CCL2 in anti-EGFR mAb-induced leukocyte migration. Our findings demonstrate that anti-EGFR mAb induces leukocyte infiltration to tumor spheroids by upregulating chemokine expression. This novel mechanism for anti-EGFR mAb action may contribute to the antitumor effects of anti-EGFR mAb in vivo.
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