Project description:In this study, we sought to determine how IL-17 and TNF influence normal human melanocytes, either alone, or with both cytokines together. We reveal a dichotomous effect of IL-17 and TNF, which not only elicit essential mitogenic cytokines but also suppress melanogenesis by down-regulating genes of melanogenesis pathway Comparison of one batch of primary human melanocyte line cultured in serum free media, treated with TNF and/or IL-17, for either 24 or 48 hours.
Project description:In this study, we sought to determine how IL-17 and TNF influence normal human melanocytes, either alone, or with both cytokines together. We reveal a dichotomous effect of IL-17 and TNF, which not only elicit essential mitogenic cytokines but also suppress melanogenesis by down-regulating genes of melanogenesis pathway
Project description:We sought to provide a comprehensive evaluation of the effects of TNF-α and IL-17 on the keratinocyte gene profile in order to identify genes that might be co-regulated by these cytokines. We then sought to determine how genes that were synergistically activated by both cytokines relate to the psoriasis transcriptome. Here, we identified 160 unique genes that were synergistically up-regulated by IL-17 and TNF-α and 188 unique genes where the two cytokines had at least an additive effect. Among highly up-regulated genes were those involved in neutrophil and lymphocyte chemotaxis, inflammation, and epidermal differentiation. Synergistically up-regulated genes included some of the highest expressed genes in lesional psoriatic skin with an impressive correlation between IL-17/TNF-α induced genes and the psoriasis gene signature. In conclusion, keratinocytes may be key drivers of pathogenetic inflammatory circuits in psoriasis through integrating responses to TNF-α and IL-17. This may explain high efficacy of targeting psoriasis with either anti-TNF-α or agents that block Th17 T-cells/IL-17 and has important implications for the development of new therapeutic agents. Comparison of keratinocyte responses to IL-17, TNF-α (1 ng mL-1 and 10 ng mL-1), and the combination of both cytokines in psoriasis.
Project description:We sought to provide a comprehensive evaluation of the effects of TNF-α and IL-17 on the keratinocyte gene profile in order to identify genes that might be co-regulated by these cytokines. We then sought to determine how genes that were synergistically activated by both cytokines relate to the psoriasis transcriptome. Here, we identified 160 unique genes that were synergistically up-regulated by IL-17 and TNF-α and 188 unique genes where the two cytokines had at least an additive effect. Among highly up-regulated genes were those involved in neutrophil and lymphocyte chemotaxis, inflammation, and epidermal differentiation. Synergistically up-regulated genes included some of the highest expressed genes in lesional psoriatic skin with an impressive correlation between IL-17/TNF-α induced genes and the psoriasis gene signature. In conclusion, keratinocytes may be key drivers of pathogenetic inflammatory circuits in psoriasis through integrating responses to TNF-α and IL-17. This may explain high efficacy of targeting psoriasis with either anti-TNF-α or agents that block Th17 T-cells/IL-17 and has important implications for the development of new therapeutic agents.
Project description:IL-17 and TNF-alpha synergistically induce surface expression of IL-13Ra2 on primary lung fibroblasts, rendering them unresponsive to IL-13. Neutralizing antibodies to IL-13Ra2 restored IL-13-mediated signaling and transcriptome studies confirmed IL-13Ra2 is an IL-13 decoy receptor.
Project description:These experiments are cytokine stimulations (TNF, IL-17, IFNg) of three keratinocyte lines (HAHA, PAK and BS4). Aim is to determine the metabolic changes induced by these cytokines and correlate with metabolomic profiling of psoriatic, uninvolved and normal skin.
Project description:Cytokines such as TNF-alpha and IL-1beta are known for their contribution to inflammatory processes in liver . In contrast, the cytokine IL-17 has not yet been assigned a role in liver diseases. IL-17 can cooperate with TNF-alpha to induce a synergistic response on several target genes in different cell lines, but no data exist for primary hepatocytes. To enhance our knowledge on the impact of IL-17 alone and combined with TNF-alpha in primary murine hepatocytes a comprehensive microarray study was designed. IL-1beta was included as this cytokine is suggested to act in a similar manner as the combination of TNF-alpha and IL-17, especially with respect to its role in mRNA stabilization. Results: The present microarray analysis demonstrates that primary murine hepatocytes responded to IL-17 stimulation by upregulation of chemokines and genes, which are functionally responsible to increase and sustain inflammation. Cxcl2, Nfkbiz and Zc3h12a were strongly induced, whereas the majority of the genes were only very moderately upregulated. Promoter analysis revealed involvement of NF-kappaB in the activation of many genes. Combined stimulation of TNF-alpha/IL-17 resulted in enhanced induction of gene expression, but significantly synergistic effects could be applied only to a few genes, such as Nfkbiz, Cxcl2, Zc3h12 and Steap4. Comparison of the gene expression profile obtained after stimulation of TNF-alpha/IL-17 versus IL-1 proposed a IL-1beta-like effect of the latter cytokine combination. Moreover, evidence was provided that modulation of mRNA stability may be a major mechanism by which IL-17 regulates gene expression in primary hepatocytes. This assumption was exemplarily proven for Nfkbiz mRNA for the first time in hepatocytes. Our studies also suggest that RNA stability can partially be correlated to the existence of AU rich elements, but further mechanisms like the RNase-activity of the upregulated Zc3h12a have to be considered. Conclusions: Our microarray analysis gives new insights in IL-17 induced gene expression in primary hepatocytes highlighting the crosstalk with the NF-kappaB signalling pathway. Gene expression profile suggests IL-17 a role in sustaining liver inflammatory processes most likely by RNA stabilization. Altogether, our results provide evidence that IL-17 alone and in concert with TNF-alpha may play a role in inflammatory liver diseases. Primary murine hepatocytes of three animals stimulated for 1 or 4h by TNF-alpha, IL-1beta, IL-17 or TNF-alpha followed by IL-17 were used for microarray analysis.
Project description:Nrf2-Keap1 signaling pathway protects cells against photo-oxidative stress. Yet in recent works, its role in melanogenesis together with cell protection functions against oxidative stress has been gaining interest. However, its effect on melanogenesis still has contradictory results from different studies. The aims of our study were to investigate the effect of Keap1 silencing in melanocyte on melanogenesis and its associated mechanism. Primary human epidermal melanocytes and melan-a cell line were used for this experiment. RNA sequencing was done to identify genes involved in melanocyte biology using Keap1 knockdown through siRNA techniques. And melanogenesis and the expression of melanogenesis-associated molecules were evaluated in Keap1 silenced melanocyte to examine the effects of Keap1 on melanogenesis, melanocyte growth, and related pathways. RNA-sequencing data revealed that Keap1 knockdown in primary human epidermal melanocytes (PHEMs) induced cell survival-related gene expression. Additionally, siRNA-mediated inhibition of Keap1 led to upregulation of MITF and melanogenesis-associated molecules along with Nrf2 activation in PHEMs. HO-1, a major gene that is upregulated in RNA-sequencing using Keap1-silenced PHEMs, protected melanocytes against H2O2-induced cell death and upregulated MITF and β-catenin expression. Further, increased expression of melanogenesis-associated molecules after Keap1 silencing was validated to occur through HO-1-associated β-catenin activation in a Keap1 and HO-1 double knockdown experiment. This work suggests that Keap1 silencing in melanocytes induced melanogenesis and the expression of melanogenesis-associated molecules through HO-1-associated β-catenin activation. Keap1 downregulation in melanocytes is important for cell proliferation and survival.
Project description:To provide a global perspective on the relationships between macrophage activation programs and to understand how certain pathogens circumvent them, we used transcriptional profiling by genome wide microarray analysis to compare the responses of mouse macrophages following exposure to the intracellular parasites Trypanosoma cruzi and Leishmania mexicana, the bacterial product lipopolysaccharide (LPS), and the cytokines IFNG, TNF, IFNB, IL-4, IL-10, and IL-17. We found that LPS induced a classical activation state that resembled macrophage stimulation by the Th1 cytokines IFNG and TNF. However, infection by the protozoan pathogen Leishmania mexicana produced so few transcriptional changes that the infected macrophages were almost indistinguishable from uninfected cells. Trypanosoma cruzi activated macrophages produced a transcriptional signature characterized by the induction of interferon-stimulated genes by 24 h post-infection. Despite this delayed IFN response by T. cruzi, the transcriptional response of macrophages infected by the kinetoplastid pathogens more closely resembled the transcriptional response of macrophages stimulated by the cytokines IL-4, IL-10, and IL-17 than macrophages stimulated by Th1 cytokines. Keywords: Bone marrow macrophage response to intracellular parasites and cytokines We analyzed a series MEEBO arrays on which were hybed RNA amplified from bone marrow-derived macrophages from C57BL/6 mice. Macrophages infected with L. mexicana or T. cruzi or stimulated by LPS, IFNG, IL-4, IL-10, TNF, IFNB, or IL-17 were compared to one another as well as to uninfected, unstimulated control macrophages. All experiments were performed over a 24 h timecourse with timepoints taken at 2 h, 6 h, 12 h, and 24 h.
Project description:Cytokines such as TNF-alpha and IL-1beta are known for their contribution to inflammatory processes in liver . In contrast, the cytokine IL-17 has not yet been assigned a role in liver diseases. IL-17 can cooperate with TNF-alpha to induce a synergistic response on several target genes in different cell lines, but no data exist for primary hepatocytes. To enhance our knowledge on the impact of IL-17 alone and combined with TNF-alpha in primary murine hepatocytes a comprehensive microarray study was designed. IL-1beta was included as this cytokine is suggested to act in a similar manner as the combination of TNF-alpha and IL-17, especially with respect to its role in mRNA stabilization. Results: The present microarray analysis demonstrates that primary murine hepatocytes responded to IL-17 stimulation by upregulation of chemokines and genes, which are functionally responsible to increase and sustain inflammation. Cxcl2, Nfkbiz and Zc3h12a were strongly induced, whereas the majority of the genes were only very moderately upregulated. Promoter analysis revealed involvement of NF-kappaB in the activation of many genes. Combined stimulation of TNF-alpha/IL-17 resulted in enhanced induction of gene expression, but significantly synergistic effects could be applied only to a few genes, such as Nfkbiz, Cxcl2, Zc3h12 and Steap4. Comparison of the gene expression profile obtained after stimulation of TNF-alpha/IL-17 versus IL-1 proposed a IL-1beta-like effect of the latter cytokine combination. Moreover, evidence was provided that modulation of mRNA stability may be a major mechanism by which IL-17 regulates gene expression in primary hepatocytes. This assumption was exemplarily proven for Nfkbiz mRNA for the first time in hepatocytes. Our studies also suggest that RNA stability can partially be correlated to the existence of AU rich elements, but further mechanisms like the RNase-activity of the upregulated Zc3h12a have to be considered. Conclusions: Our microarray analysis gives new insights in IL-17 induced gene expression in primary hepatocytes highlighting the crosstalk with the NF-kappaB signalling pathway. Gene expression profile suggests IL-17 a role in sustaining liver inflammatory processes most likely by RNA stabilization. Altogether, our results provide evidence that IL-17 alone and in concert with TNF-alpha may play a role in inflammatory liver diseases.