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: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.
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: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:The increased secretion of pro-inflammatory cytokines, such as tumor necrosis factor-alpha, is often associated with adipose tissue dysregulation, which often accompanies obesity. High levels of TNF-alpha have been linked to development of insulin resistance in several tissues and organs, including skeletal muscle and the liver. In this study, we examined the complex regulatory roles of TNF-alpha in murine hepatocytes utilizing a combination of global proteomics and phosphoproteomics analyses. Our results show that TNF-alpha promotes extensive, dynamic changes not only of protein levels, but also the dynamics of their downstream phosphorylation signaling states. We provide evidence that TNF-alpha likely induces DNA replication, and promotes G1/S transition through the activation of the MAPK pathway. Our data also highlights several other novel proteins, many of which are regulated by phosphorylation and that play a role in the progression and development of insulin resistance in hepatocytes.
Project description:The liver is composed of different cell populations. Interactions of different cell populations can be investigated bya newly established indirect co-culture system consisting of immortalised primary human hepatocytes and human monocyte derived macrophages(MDMs). Using the time-dependent cytokine secretion of the co-cultures and singlecultures, correlation networks(includingthe cytokinesG-CSF, CCL3, MCP-1, CCL20, FGF, TGF-β1, GM-CSF, IL-8 IL-6, IL-1β, and IL-18)were generated and the correlationswere validatedbyapplication of IL-8and TNF-α-neutralising antibodies. Thedata reveal that IL-8 is crucial for the interaction between hepatocytes and macrophages in vitro.In addition, transcriptome analyses showedthat a change in the ratio between macrophages and hepatocytes may triggerpro-inflammatory signalling pathways of the acute phase responseand the complement system(release of, e.g., certaincyto-and chemokines).Using diclofenac and LPS showed that the release of cytokines is increasingwith higher ratios of MDMs. Altogether we coulddemonstratethat the current co-culture system is better suited to mirror thein vivosituation when compared to previously established co-culturesystems composed of HepG2and differentiated THP-1cells.Further, our data reveal that the cytokine IL-8 is crucial for the interaction between hepatocytes and macrophages in vitro.
Project description:Interventions: Group A:Simple general anesthesia;Group B:QLB combined with general anesthesia
Primary outcome(s): Tumor necrosis factor-alpha, TNF-a;Interleukin-6, IL-6;Interleukin-10, IL-10;Postoperative intestinal function recovery time;Feeding time;The incidence and extent of abdominal distention
Study Design: Parallel