Project description:Interleukin-17 (IL-17) is essential in host defense against extracellular bacteria and fungi, especially at mucosal sites, but it also contributes significantly to inflammatory and autoimmune disease pathologies. Binding of IL-17 to its receptor leads to recruitment of the adaptor protein CIKS/Act1 via heterotypic association of their respective SEFIR domains and to activation of the transcription factor NF-kB; it is not known whether CIKS and/or NF-kB are required for all gene induction events. Here we report that CIKS is essential for all IL-17 induced immediate-early genes in primary mouse embryo fibroblasts, while NF-kB is profoundly involved. We also identify a novel sub-domain in the N-terminus of CIKS that is essential for IL-17-mediated NF-kB activation. This domain is both necessary and sufficient for the interaction between CIKS and TRAF6, an adaptor required for NF-kB activation. The ability of decoy peptides to block this interaction may provide a new therapeutic strategy for intervention in IL-17-driven autoimmune and inflammatory diseases. Keywords: strain comparisons strain comparisons
Project description:Interleukin-17 (IL-17) is essential in host defense against extracellular bacteria and fungi, especially at mucosal sites, but it also contributes significantly to inflammatory and autoimmune disease pathologies. Binding of IL-17 to its receptor leads to recruitment of the adaptor protein CIKS/Act1 via heterotypic association of their respective SEFIR domains and to activation of the transcription factor NF-kB; it is not known whether CIKS and/or NF-kB are required for all gene induction events. Here we report that CIKS is essential for all IL-17 induced immediate-early genes in primary mouse embryo fibroblasts, while NF-kB is profoundly involved. We also identify a novel sub-domain in the N-terminus of CIKS that is essential for IL-17-mediated NF-kB activation. This domain is both necessary and sufficient for the interaction between CIKS and TRAF6, an adaptor required for NF-kB activation. The ability of decoy peptides to block this interaction may provide a new therapeutic strategy for intervention in IL-17-driven autoimmune and inflammatory diseases. Keywords: strain comparisons
Project description:IL-17 mediates immune protection from fungi and bacteria as well as it promotes autoimmune pathologies. However, the regulation of the signal transduction from the IL-17 receptor (IL-17R) remained elusive. We developed a novel mass spectrometry-based approach to identify components of the IL-17R complex followed by analysis of their roles using reverse genetics. Besides the identification of LUBAC as an important signal transducing component of IL-17R, we established that IL-17 signaling is regulated by a robust negative feedback loop mediated by TBK1 and IKKε. These kinases terminate IL-17 signaling by phosphorylating the adaptor ACT1 leading to the release of the essential ubiquitin ligase TRAF6 from the complex. NEMO recruits both kinases to the IL-17R complex, documenting that NEMO has an unprecedented negative function in IL-17 signaling, distinct from its role in NF-κB activation. Our study provides a comprehensive view of the molecular events of the IL-17 signal transduction and its regulation.
Project description:The IL-17 receptor adaptor molecule Act1, an RNA binding protein, plays a critical role in IL-17-mediated cancer progression. Here we report a novel mechanism for how IL-17/Act1 induces chemoresistance by modulating redox homeostasis through epitranscriptomic regulation of antioxidant RNA metabolism. Transcriptome-wide mapping of direct Act1-RNA interactions revealed that Act1 binds to the 5'UTR of antioxidant mRNAs and Wilms' tumor 1-associating protein (WTAP), a key regulator in m6A methyltransferase complex. Strikingly, Act1's binding sites are located in proximity to m6A modification sites, which allows Act1 to promote the recruitment of elF3G for cap-independent translation. Loss of Act1’s RNA binding activity or Wtap knockdown abolished IL-17-induced m6A modification and translation of Wtap and antioxidant mRNAs, indicating a feedforward mechanism of Act1-WTAP loop. We then developed antisense oligonucleotides (Wtap ASO) that specifically disrupts Act1’s binding to Wtap mRNA, abolishing IL-17/Act1-WTAP-mediated antioxidant protein production during chemotherapy. Wtap ASO substantially increased the antitumor efficacy of cisplatin, demonstrating a potential therapeutic strategy for chemoresistance.
Project description:The IL-17 receptor adaptor molecule Act1, an RNA binding protein, plays a critical role in IL-17-mediated cancer progression. Here we report a novel mechanism for how IL-17/Act1 induces chemoresistance by modulating redox homeostasis through epitranscriptomic regulation of antioxidant RNA metabolism. Transcriptome-wide mapping of direct Act1-RNA interactions revealed that Act1 binds to the 5'UTR of antioxidant mRNAs and Wilms' tumor 1-associating protein (WTAP), a key regulator in m6A methyltransferase complex. Strikingly, Act1's binding sites are located in proximity to m6A modification sites, which allows Act1 to promote the recruitment of elF3G for cap-independent translation. Loss of Act1’s RNA binding activity or Wtap knockdown abolished IL-17-induced m6A modification and translation of Wtap and antioxidant mRNAs, indicating a feedforward mechanism of Act1-WTAP loop. We then developed antisense oligonucleotides (Wtap ASO) that specifically disrupts Act1’s binding to Wtap mRNA, abolishing IL-17/Act1-WTAP-mediated antioxidant protein production during chemotherapy. Wtap ASO substantially increased the antitumor efficacy of cisplatin, demonstrating a potential therapeutic strategy for chemoresistance.
Project description:5-Fuorouracil (5-Fu) remains one of the most effective and most commonly used drugs to treat colorectal cancer. Mucositis is a major complication that occurs in approximately 80% of patients receiving 5-FU and results in abdominal bloating as well as vomiting and diarrhea. oral mucositis (OM) are often very painful and compromise nutrition and oral hygiene as well as increase risk for local and systemic infection.
OM is characterized by an intense inflammatory reaction on the mucosa lamina propria cells, which results in activation of the transcription factor NF-kB. The activation of NF-kB leads to transcription of genes involved in the synthesis of pro-inflammatory cytokines, such as IL-1β, IL-6 and TNF-α. Agents known to attenuate the expression of cytokines have demonstrated efficacy in the prevention of experimental mucositis.
The use of atorvastatin were associated with reduced production of TNF-α and IL-1β and decreased neutrophil infiltration evidenced by histopathological analysis and Myeloperoxidase (MPO) activity. In addition, atorvastatin also reduced oxidative stress and induced an increase in non-protein sulfhydryl groups showing anti-inflammatory and immunomodulatory action.
Project description:The efficacy of monoclonal antibodies against either interleukin (IL)-17 or the IL-17 receptor in psoriasis therapy provides strong evidence that IL-17 is the major inflammatory mediation in this disease. However, how IL-17 induces epidermal hyperplasia in psoriasis remains largely unknown. Here, we show that IL-17 actives NF-kB in keratinocytes and initiates the NF-kB-dependent transcription of microRNA-31 (miR-31), one of the most abundant microRNAs in the epidermis of lesional skin of psoriasis and two related mouse models. Similar to IL-17 deficiency (IL-17-/-), knocking out miR-31 (miR-31-/-) or targeting it by antagomir-31 prevents keratinocytes Ki67 expression and inhibits acanthosis and dermal inflammation in psoriasis mouse model. Moreover, PPP6c, a negative regulator restricting G0/G1 to G2/M phase progression in the cell cycle, is diminished in human psoriatic epidermis and is directly targeted by miR-31. Inhibition of ppp6c is functionally important for the biological effects of miR-31 in the development of epidermal hyperplasia. Thus, our data define IL-17-inducede miR-31 and its target ppp6c as critical factors for hyperproliferative epidermis in psoriasis.
Project description:Our study indicates that lncRNA TRAF3IP2-AS1 serving as a negative regulator of Act1 transcriptional expression and IL-17 signaling pathway activity,recruits SRSF10 to downregulate the transcription of IRF1, which is itself a transcriptional factor for Act1. And the psoriasis-susceptible variant A4165G of TRAF3IP2-AS1 is a gain-of-function mutant that binds more strongly than the wild-type form to SRSF10. It means that TRAF3IP2-AS1 or SRSF10 may be a good target for the treatment of human IL-17-related autoimmune diseases.