Project description:Pedro Vizán, Daniel S. J. Miller, Ilaria Gori, Debipriya Das, Bernhard Schmierer & Caroline S. Hill. Controlling long-term signaling: receptor dynamics determine attenuation and refractory behavior of the TGF-β pathway. Science Signaling 6, 305 (2013).
Understanding the complex dynamics of growth factor signaling requires both mechanistic and kinetic information. Although signaling dynamics have been studied for pathways downstream of receptor tyrosine kinases and G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptors, they have not been investigated for the transforming growth factor-β (TGF-β) superfamily pathways. Using an integrative experimental and mathematical modeling approach, we dissected the dynamic behavior of the TGF-β to Smad pathway, which is mediated by type I and type II receptor serine/threonine kinases, in response to acute, chronic, and repeated ligand stimulations. TGF-β exposure produced a transient response that attenuated over time, resulting in desensitized cells that were refractory to further acute stimulation. This loss of signaling competence depended on ligand binding, but not on receptor activity, and was restored only after the ligand had been depleted. Furthermore, TGF-β binding triggered the rapid depletion of signaling-competent receptors from the cell surface, with the type I and type II receptors exhibiting different degradation and trafficking kinetics. A computational model of TGF-β signal transduction from the membrane to the nucleus that incorporates our experimental findings predicts that autocrine signaling, such as that associated with tumorigenesis, severely compromises the TGF-β response, which we confirmed experimentally. Thus, we have shown that the long-term signaling behavior of the TGF-β pathway is determined by receptor dynamics, does not require TGF-β-induced gene expression, and influences context-dependent responses in vivo.
Project description:To elucidate the epithelial cell diversity within the nasal inferior turbinates, a comprehensive investigation was conducted comparing control subjects to individuals with house dust mite-induced allergic rhinitis. This study aimed to delineate the differential expression profiles and phenotypic variations of epithelial cells in response to allergic rhinitis. This research elucidated distinct subpopulations and rare cell types of epithelial cells within the nasal turbinates, discerning alterations induced by allergic rhinitis. Furthermore, by interrogating transcriptomic signatures, the investigation provided novel insights into the cellular dynamics and immune responses underlying allergic rhinitis pathogenesis
Project description:Transforming growth factor (TGF)-β signaling is a key driver to induce epithelial-to-mesenchymal transition (EMT), a process that enhances cancer cell plasticity and metastatic potential. However, the role of circular RNAs (circRNAs) in TGF-β signaling remains largely unexplored. Here, we identify circTBRII(3-6), a circRNA derived from TGF-β type II receptor (TBRII) pre-mRNA, as a critical enhancer of TGF-β/SMAD signaling in breast cancer cells. Depletion of circTBRII(3-6) inhibits TGF-β-induced EMT, migration, and in vivo extravasation of breast cancer cells. Mechanistically, circTBRII(3-6) acts as a scaffold that facilitates the interaction between the RNA-binding protein insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) and TGF-β type I receptor (TBRI) mRNA in an N6-methyladenosine (m6A)-dependent manner, and thereby stabilizes TBRI and promotes its expression. Furthermore, IGF2BP3 knockdown reduces circTBRII(3-6)-mediated enhancement of TGF-β/SMAD signaling, as well as TGF-β-induced EMT and migration. Our findings identify circTBRII(3-6) as a novel enforcer of TGF-β/SMAD signaling at the receptor level and highlight IGF2BP3 as a critical m6A reader that mediates circTBRII(3-6)-driven breast cancer cell plasticity.
Project description:Investigation of transcript level modulation in unstimulated and TGF-beta treated (with or without superimposed T-cell receptor and CD28 stimulation) naive CD4 T cells from wild type or Smad3-deficient littermate mice. Smad3 is a critical signaling molecule and transcription factor downstream of TGF-beta and mediates several of the TGF-beta dependent tolerogenic effects in T cells. This study was undertaken to unveil the transcriptionnal program controled by the TGF-b/Smad3 axis.
Project description:Investigation of transcript level modulation in unstimulated and TGF-beta treated (with or without superimposed T-cell receptor and CD28 stimulation) naive CD4 T cells from wild type or Smad3-deficient littermate mice. Smad3 is a critical signaling molecule and transcription factor downstream of TGF-beta and mediates several of the TGF-beta dependent tolerogenic effects in T cells. This study was undertaken to unveil the transcriptionnal program controled by the TGF-b/Smad3 axis. Microarray study using RNA recovered after 6 hours of culture in either serum free media, serum-free media + TGF-beta (2.5ng/ml) or serum-free media + TGF-beta and anti-CD3e and anti-CD28 stimulation (3 conditions). Naive CD4 T cells (TCRb+, CD4+, CD62L+ and CD44-) were sorted from either wild type or Smad3 deficient littermates and submitted to the 3 culture conditions. Three biological replicates were obtained (each from at least 2 different mice). Thus a total of 18 Nimblegen 365K chip were used.
Project description:Cancer-associated fibroblasts (CAFs) are a major stromal cell type within the tumor microenvironment (TME). Transforming growth factor-β (TGF-β) is a key cytokine in the TME that activates CAFs, which alters their ability to remodel the extracellular matrix (ECM) and changes their secretome profile. However, the effects of TGF-β-activated CAF-derived extracellular vesicles (EVs) on the TME, and how TGF-β-induced CAF activation influences the composition of EV cargo and remodels the TME remain largely unexplored. In this study, we reveal the altered protein composition and function of EVs derived from TGF-β-activated CAFs compared to those derived from non-activated CAF-derived EVs. Notably, several proteins that are significantly upregulated in TGF-β-activated CAF-derived EVs (TGF-β-EVs) are found on the surface of these EVs. One such protein is tumor necrosis factor-stimulated gene-6 protein (TSG6), which interacts with its receptor CD44 on the EVs and hyaluronan. These surface-associated proteins facilitate the docking of EVs to cell membrane by binding to transmembrane cell surface receptors. The elevated TSG6 on EV surface promotes the clustering of the co-receptor CD44, and TGF-β type I receptor (TGFBR1) on recipient cells, and thereby enhancing TGF-β receptor signaling. Consequently, TGF-β-EVs further activate CAFs and contribute to the immunosuppression of CD8+ T cells, which facilitates cancer progression. Overall, our findings reveal the effect of CAF-derived EVs on other cell types in TME in a contact-dependent manner, and suggest a potential universal mechanism by which EV surface-associated proteins regulate cell signaling by interacting with and clustering cell receptors, particularly in cells with low EV uptake.