Bacterial TLR2/6 Ligands Block Ciliogenesis, Derepress Hedgehog Signaling, and Expand the Neocortex
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE229699 | GEO | 2023/04/13
REPOSITORIES: GEO
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Project description:Misactivation of the Hedgehog (Hh) pathway can cause cancers such as medulloblastomas, the most common malignant brain tumor in children, and basal cell carcinomas, the most common cancer in the United States. Hedgehog signals are transmitted through primary cilia, where Hedgehog ligands bind to Patched1 and activate Smoothened through interactions with cilia-associated sterol lipids. The gene expression programs driving cellular responses to ciliary Hh signals are incompletely understood. Thus, to define Hh target genes, we performed RNA sequencing of cells after treatment with Hh ligands (Shh, Dhh, Ihh), cilia-associated lipids (7b,27-dihydroxycholesterol, 24(S),25-epoxycholesterol), or synthetic lipids or small molecules that activate Smoothened (20(S)-hydroxycholesterol, SAG). Treatment with Hh pathway agonists identified a core gene expression program comprised of 155 genes driving lipid synthesis, metabolism, signaling, adhesion, or angiogenesis. These datasets were integrated with RNA sequencing of Hh-human medulloblastomas (n=?), a Math1-Cre SmoM2 mouse genetic model of Hh-associated medulloblastoma (n=?), and human basal cell carcinomas (n=10) to ascertain how malignant Hh signaling differs from canonical Hh signaling. We discover a conserved response to ciliary Hh signals in human or mouse medulloblastomas, including known target genes such as Gli1 or Ptch1, and novel target genes such as Hsd11b1 or Retnla. Importantly, mechanistic studies reveal Hsd11b1 to be a putative negative regulator of Hh signaling that is dysregulated in malignancies. We further demonstrate Retnla to be a positive regulator of Hh signaling that drives expression of Hsd11b2, a druggable dependency underlying Hedgehog-associated medulloblastoma. Orthotopic implantation of neuroepithelial stem cells that overexpress either Hsd11b1 and Retnla demonstrate that tumors derived Hsd11ß1 overexpression are more primitive and less aggressive whereas Retnla overexpression forms tumors that are more differentiated and behave more aggressively. In sum, we illuminate the first comprehensive transcriptome of Hh signaling and highlight the intricate interplay between Hh signaling and lipid metabolism that Hh-dependent malignancies dysregulate to drive tumor progression.
2023-06-06 | GSE233744 | GEO
Project description:Cilia are organelles specialized for movement and signaling. To infer when during animal evolution signaling pathways became associated with cilia, we characterized the proteomes of cilia from three organisms: sea urchins, sea anemones and choanoflagellates. From these ciliomes, we identified 437 high confidence ciliary candidate proteins conserved in mammals, including known regulators of Hh, GPCR and TRP channel signaling. The phylogenetic profiles of their ciliary association indicate that the Hh and GPCR pathways were linked to cilia before the origin of bilateria and TRP channels before the origin of animals. We demonstrated that some of the candidates not previously implicated in ciliary biology localized to cilia and further investigated ENKUR, a TRP channel-interacting protein that we identified in the cilia of all three organisms. In animals, ENKUR is expressed by cells with motile cilia, ENKUR localizes to cilia in diverse organisms and, in both Xenopus laevis and mice, ENKUR is required for patterning the left/right axis. Moreover, mutation of ENKUR causes situs inversus in humans. Thus, proteomic profiling of cilia from diverse eukaryotes defines a conserved ciliary proteome, reveals ancient connections to Hh, GPCR and TRP channel signaling, and uncovers a novel ciliary protein that controls vertebrate development and human disease.
2019-12-16 | PXD006632 | Pride
Project description:Remyelination after white matter injury (WMI) often fails in diseases such as multiple sclerosis due to improper recruitment and repopulation of oligodendrocyte precursor cells (OPCs) in lesions. How OPCs elicit specific intracellular programs in response to a chemically and mechanically diverse environment to properly regenerate myelin remains unclear. OPCs construct primary cilia, specialized signaling compartments that transduce Hh and GPCR signals. We investigated the role of primary cilia in the OPC response to WMI. Removing cilia from OPCs genetically via deletion of Ift88 results in OPCs failing to repopulate WMI lesions due to reduced proliferation. Interestingly, loss of cilia does not affect Hh signaling in OPCs or their responsiveness to Hh signals, but instead leads to dysfunctional cAMP-dependent CREB-mediated transcription. As inhibition of CREB activity in OPCs reduces proliferation, we propose that a GPCR/cAMP/CREB signaling axis initiated at OPC cilia orchestrates OPC proliferation during development and in response to WMI.
2023-09-29 | GSE243997 | GEO
Project description:Congenital lung malformations are fatal at birth in their severe forms. Prevention and early intervention of these birth defects require a comprehensive understanding of the molecular mechanisms of lung development. We find that the loss of Inturned (Intu), a cilia and planar polarity effector gene, severely disrupts growth and branching morphogenesis of the mouse embryonic lungs. Consistent with our previous results indicating an important role for Intu in ciliogenesis and hedgehog (Hh) signaling, we find greatly reduced number of primary cilia in both the epithelial and mesenchymal tissues of the lungs. We also find significantly reduced expression of Gli1 and Ptch1, direct targets of Hh signaling, suggesting disruption of cilia-dependent Hh signaling in Intu mutant lungs. An agonist of the Hh pathway activator, smoothened, increased Hh target gene expression and tubulogenesis in explanted lungs in wild type, but not Intu mutants, suggesting impaired Hh signaling response in the absence of Intu. Furthermore, removing both Gli2 and Intu completely abolishes branching morphogenesis of the lung, strongly supporting a mechanism by which Intu regulates lung growth and patterning through cilia-dependent Hh signaling. Moreover, a transcriptomics analysis identifies around 200 differentially expressed genes (DEGs) in Intu mutant lungs, including known Hh target genes Gli1, Ptch1/2 and Hhip. Genes involved in muscle differentiation and function are highly enriched among the DEGs, consistent with an important role of Hh signaling in airway smooth muscle differentiation. In addition, we find a diminishing difference in gene expression between the left and right lungs in Intu mutants, suggesting an important role of Intu in asymmetrical growth and patterning of the mouse lungs.
2024-03-31 | GSE251669 | GEO
Project description:Basal cell carcinomas (BCCs) rely on Hedgehog (HH) pathway growth signal amplification by the microtubule-based organelle, the primary cilium. Despite naïve tumors responsiveness to Smoothened inhibitors (Smoi), resistance in advanced tumors remains frequent. While the resistant BCCs usually maintain HH pathway activation, squamous cell carcinomas with Ras/MAPK pathway activation also arise, with the molecular basis of tumor type and pathway selection still obscure. Here we identify the primary cilium as a critical determinant controlling tumor pathway switching. Strikingly, Smoi-resistant BCCs possess an increased mutational load in ciliome genes, resulting in reduced primary cilia and HH pathway activation compared to naive or Gorlin patient BCCs. Gene set enrichment analysis of resistant BCCs with a low HH pathway signature reveals increased Ras/MAPK pathway activation. Tissue analysis confirms an inverse relationship between primary cilia presence and Ras/MAPK activation, and primary cilia removal in BCCs potentiates Ras/MAPK pathway activation. Moreover, activating Ras in HH-responsive cell lines confers resistance to both canonical (vismodegib) and non-canonical (aPKC and MRTF inhibitors) HH pathway inhibitors, while conferring sensitivity to MAPK inhibitors. Our results provide new insights into BCC treatment and identify the primary cilium as an important lineage gatekeeper, preventing HH to Ras/MAPK pathway switching.
2018-10-10 | GSE120954 | GEO
Project description:Injured skeletal muscle regenerates, but with age or in muscular dystrophies, muscle is replaced by fat. Upon injury, muscle-resident fibro/adipogenic progenitors (FAPs) proliferated and gave rise to adipocytes. These FAPs dynamically produced primary cilia, structures that transduce intercellular cues such as Hedgehog (Hh) signals. Genetically removing cilia from FAPs inhibited intramuscular adipogenesis, both after injury and in a mouse model of Duchenne muscular dystrophy. Blocking FAP ciliation also enhanced myofiber regeneration after injury and reduced myofiber size decline in the muscular dystrophy model. Hh signaling through FAP cilia regulated the expression of TIMP3, a secreted metalloproteinase inhibitor, that inhibited MMP14 to block adipogenesis. A pharmacological mimetic of TIMP3 blocked the conversion of FAPs into adipocytes, pointing to a strategy to combat fatty degeneration of skeletal muscle. We conclude that ciliary Hh signaling by FAPs orchestrates the regenerative response to skeletal muscle injury.
2017-07-13 | GSE86073 | GEO
Project description:The neural stem cell decision to self-renew or differentiate is tightly regulated by its microenvironment. Here, we have asked about this microenvironment, focusing on growth factors in the embryonic cortex at a time when it is largely comprised of neural precursor cells (NPCs) and newborn neurons. We show that cortical NPCs secrete factors that promote their maintenance while cortical neurons secrete factors that promote differentiation. To define factors important for these activities, we used transcriptome profiling to identify ligands produced by NPCs and neurons, cell surface mass spectrometry to identify receptors on these cells, and computational modeling to integrate these data. The resultant model predicts a complex growth factor environment with multiple autocrine and paracrine interactions. We tested this communication model, focusing on neurogenesis, and identified IFNγ, Nrtn and glial-derived neurotrophic factor (GDNF) as ligands with unexpected roles in promoting neurogenic differentiation of NPCs in vivo. We prepared E16 cortical neuron, E13 cortical precursor and co-cultured E16 cortical neuron and E13 cortical precursor cultures from three independent biological replicates.
2016-08-23 | E-GEOD-84482 | biostudies-arrayexpress
Project description:Clinical approaches to treat advanced melanoma include immune therapies, whose benefits depend on tumor-reactive T-cells to infiltrate metastases. However, most tumors lack significant immune infiltration prior to therapy, and some immune therapies are hindered by a persistent lack of immune cell infiltration. CXCL10 has been implicated as a critical chemokine supporting T-cell migration into tumors; thus agents that induce CXCL10 in tumors may improve patient responses to systemic immune therapy. We find that melanoma cells treated with TLR2/6 agonists (MALP-2 or FSL-1) and interferon-gamma (IFNgamma) upregulate CXCL10 production, when compared to IFNgamma treatment alone or no treatment. Gene profiling of melanoma cells lines treated with TLR2/6 agonists and IFNgamma demonstrate that a selective profile of genes are induced which may be favorable for promoting immune cell infiltration of tumors. TLR2 and TLR6 are widely expressed on human melanoma cells, and treatment of melanoma cells with TLR2/6 agonists and IFNgamma does not hinder melanoma cell apoptosis or promote proliferation. Furthermore, melanoma cells from surgically resected patient tumors upregulate CXCL10 production after treatment with TLR2/6 agonists and IFNgamma when compared to treatment with either agent alone. Collectively, these data identify TLR2/6 agonists and IFNgamma as a novel target for promoting CXCL10 production directly from melanoma cells. Samples from four human melanoma cell lines, VMM1 (n=6), DM13 (n=6), DM93 (n=6) and VMM39 (n=6), were treated with media alone, MALP-2 (TLR2/6 agonist), FSL-1 (TLR2/6 agonist), IFNgamma alone, MALP-2 and IFNgamma, or FSL-1 and IFNgamma.
2015-11-22 | E-GEOD-64506 | biostudies-arrayexpress
Project description:Background. Primary cilia (PC) are solitary antennae present at the cell surface. These non-motile cilia play an important role in organ development and tissue homeostasis through the transduction of the Hedgehog (Hh) signaling pathway. We recently revealed the presence of PC in the epithelium of the developing epididymis, an organ of the male reproductive system whose dysfunction triggers male infertility. Acknowledging that systemic blockade of the Hh pathway trigger epididymal dysfunctions in vivo, our main goals were 1) to portray the epididymal Hh environment, 2) to determine the direct responsiveness of epididymal epithelial cells to Hh, and 3) to define the contribution of PC to the transduction of this pathway. Results. The Hh ligands Indian and Sonic hedgehog (Ihh and Shh) were respectively located in principal and clear cells of the mouse epididymis by immunofluorescent staining. The propensity of epididymal principal cells to respond to Hh signaling was assessed on immortalized epididymal DC2 cells by western-blot, confocal imaging and 3D-reconstruction. Our results indicate that epididymal principal cells secrete Ihh and expose PC that co-localize with the conventional acetylated tubulin/Arl13b ciliary markers, as well as with GLI3 Hh signaling factor. Gene expression microarray profiling indicated that the expression of 43 and 248 genes was respectively and significantly modified following pharmacological treatment of DC2 cells with the Hh agonist SAG (250 nM) or the Hh antagonist cyclopamine (20 µM) compared with the control. Among Hh target genes identified, 6.7 % presented perfect matches for GLI-transcription factor consensus sequences, and the majority belonged to interferon-dependent immune response and lipocalin 2 pathways. Finally, the contribution of epididymal PC to the transduction of canonical Hh pathway was validated by ciliobrevinD treatment, which induced a significant decrease of PC length and the expressional reduction of Hh signalling targets. Conclusions. All together our data indicate that PC from epithelial principal cells regulate gene expression profile through a possible autocrine Hh signaling. This provides new hypotheses regarding the potential contribution of PC and Hh signaling in intercellular cross-talk and immunological regulation of the epididymis.
2020-04-17 | GSE143829 | GEO
Project description:Clinical approaches to treat advanced melanoma include immune therapies, whose benefits depend on tumor-reactive T-cells to infiltrate metastases. However, most tumors lack significant immune infiltration prior to therapy, and some immune therapies are hindered by a persistent lack of immune cell infiltration. CXCL10 has been implicated as a critical chemokine supporting T-cell migration into tumors; thus agents that induce CXCL10 in tumors may improve patient responses to systemic immune therapy. We find that melanoma cells treated with TLR2/6 agonists (MALP-2 or FSL-1) and interferon-gamma (IFNgamma) upregulate CXCL10 production, when compared to IFNgamma treatment alone or no treatment. Gene profiling of melanoma cells lines treated with TLR2/6 agonists and IFNgamma demonstrate that a selective profile of genes are induced which may be favorable for promoting immune cell infiltration of tumors. TLR2 and TLR6 are widely expressed on human melanoma cells, and treatment of melanoma cells with TLR2/6 agonists and IFNgamma does not hinder melanoma cell apoptosis or promote proliferation. Furthermore, melanoma cells from surgically resected patient tumors upregulate CXCL10 production after treatment with TLR2/6 agonists and IFNgamma when compared to treatment with either agent alone. Collectively, these data identify TLR2/6 agonists and IFNgamma as a novel target for promoting CXCL10 production directly from melanoma cells.
2015-11-22 | GSE64506 | GEO