Project description:Interleukin (IL)-33 is a cytokine that appears to mediate fibrosis by signaling via its receptor ST2 (IL-33R/IL1RL1). It is also, however, a protein that after synthesis is sorted to the cell nucleus, where it appears to affect chromatin folding. Here we describe a novel role for nuclear IL-33 in regulating the fibroblast phenotype in murine kidney fibrosis driven by unilateral ureteral obstruction. Transcriptional profiling of IL-33-deficient kidneys 24h after ligation revealed enhanced expression of fibrogenic genes and enrichment of gene sets involved in extracellular matrix formation and remodeling. These changes relied on intracellular effects of IL-33, because they were not reproduced by treatment with a neutralizing antibody to IL-33 that prevents IL-33R/ST2L receptor signaling nor were they observed in IL33R/ST2-deficient kidneys. To further explore the intracellular function of IL-33, we established transcription profiles of human fibroblasts, observing that knockdown of IL-33 skewed the transcription profile from an inflammatory towards a myofibroblast phenotype, reflected in higher levels of COL3A1, COL5A1 and transgelin protein, as well as lower expression levels of IL6, CXCL8, CLL7 and CCL8. In conclusion, our findings suggest that nuclear IL-33 in fibroblasts dampens the initial profibrotic response until persistent stimuli, as enforced by UUO, can override this protective mechanism.
Project description:Interleukin-33 (IL-33), a member of the IL-1 superfamily cytokines, is an endogenous danger signal and a nuclear-associated cytokine. It is one of the essential mediators of both innate and adaptive immune responses. Aberrant IL-33 signaling has been demonstrated to play a defensive role against various infectious and inflammatory diseases. Although the signaling responses mediated by IL-33 have been previously reported, the temporal signalingdynamicsare yet to be explored. Towards this end,we applied quantitative temporal phosphoproteomics analysis to elucidate pathways and proteins induced by IL-33 in THP1 monocytes. Employing TMT labeling-based quantitation and titanium dioxide (TiO2)-based phosphopeptide enrichment strategy followed by mass spectrometry analysis, we identified 14,515 phosphorylation sites mapping to 4,174 proteins across (0 min to 240 mins)time points.
Project description:Interleukin-33 (IL-33) is a member of the IL-1 family of cytokines that play a central role in the regulation of immune responses. IL-33 signaling, from the early signaling events triggered by the ligand-activated receptor to result in activation of early and late signaling events, such as proteome changes. In this study, THP1 (monocyte) cell line model was stimulated with IL-33 (50 ng/ml) for varying duration (5, 10, 15, 30, 40, 60, 120 and 240 mins). We carried out in-depth proteomic analysis using high-resolution LC-MS/MS. Our analysis resulted in the identification of 64,030 peptides corresponding to 7947 protein groups. Differentially regulated proteins identified in this study could be targeted for developing an inflammatory immune response.
Project description:Resistance to DNA damage is one of the primary mechanisms by which tumor cells evade the effects of standard chemotherapeutic agents and radiotherapy. Dynamic and complex interactions between the tumor microenvironment (TME) and tumor cells critically influence the DNA damage response. Interleukin-33 (IL-33) is a multifunctional cytokine secreted at high levels in response to cellular damage and stress. Recently, increasing evidence has suggested that IL-33 plays a key role in promoting the therapeutic resistance of tumors. However, the actual source of IL-33 during cancer therapy and how IL-33 contributes to a resistant TME remain incompletely understood. In this study, we found that both cancer-associated fibroblasts (CAFs) and tumor cells treated with DNA damage-inducing agents expressed and secreted high levels of IL-33, subsequently leading to enhanced DNA damage repair efficacy. Mechanistically, nuclear IL-33 primarily functions as a transcriptional co-activator of homologous recombination repair (HRR) genes, whereas the active form of IL-33 can drive the non-homologous end joining (NHEJ) pathway via the canonical IL-33/ST2 axis. Overall, we demonstrated that IL-33 plays a key role in mediating a DNA damage-resistant TME, which could represent a potential therapeutic vulnerability in chemoresistant cancer cells
Project description:The role of IL-33 and its receptor ST2 in kidney injury is not well understood. This study demonstrates the importance of ST2 expression on the T-regulatory cells (Tregs) for the resolution of renal injury by suppressing inflammation and fibrosis. Treg-specific deletion of ST2, detrimentally impacted late outcomes of renal injury worsening the impairment of kidney function, inflammation, and fibrosis.