scholarly journals Mechanisms of Smoothened Regulation in Hedgehog Signaling

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 2138
Author(s):  
Jie Zhang ◽  
Zulong Liu ◽  
Jianhang Jia
Keyword(s):  
Small Molecules ◽  
Intracellular Trafficking ◽  
Hedgehog Signaling ◽  
Transmembrane Protein ◽  
Developmental Defects ◽  
Hh Signaling ◽  
Development Outcomes ◽  
Late Stages ◽  
Signaling Activity

The seven-transmembrane protein, Smoothened (SMO), has shown to be critical for the hedgehog (HH) signal transduction on the cell membrane (and the cilium in vertebrates). SMO is subjected to multiple types of post-translational regulations, including phosphorylation, ubiquitination, and sumoylation, which alter SMO intracellular trafficking and cell surface accumulation. Recently, SMO is also shown to be regulated by small molecules, such as oxysterol, cholesterol, and phospholipid. The activity of SMO must be very well balanced by these different mechanisms in vivo because the malfunction of SMO will not only cause developmental defects in early stages, but also induce cancers in late stages. Here, we discuss the activation and inactivation of SMO by different mechanisms to better understand how SMO is regulated by the graded HH signaling activity that eventually governs distinct development outcomes.

scholarly journals Gene-teratogen interactions influence the penetrance of birth defects by altering Hedgehog signaling strength

Development ◽  
2021 ◽  
Vol 148 (19) ◽  
Author(s):  
Jennifer H. Kong ◽  
Cullen B. Young ◽  
Ganesh V. Pusapati ◽  
F. Hernán Espinoza ◽  
Chandni B. Patel ◽  
...  
Keyword(s):  
Small Molecules ◽  
Birth Defects ◽  
Birth Defect ◽  
Hedgehog Signaling ◽  
Multiple Birth ◽  
In Utero Exposure ◽  
Membrane Protein Complex ◽  
Protein Target ◽  
Hh Signaling ◽  
Genetic And Environmental Factors

ABSTRACT Birth defects result from interactions between genetic and environmental factors, but the mechanisms remain poorly understood. We find that mutations and teratogens interact in predictable ways to cause birth defects by changing target cell sensitivity to Hedgehog (Hh) ligands. These interactions converge on a membrane protein complex, the MMM complex, that promotes degradation of the Hh transducer Smoothened (SMO). Deficiency of the MMM component MOSMO results in elevated SMO and increased Hh signaling, causing multiple birth defects. In utero exposure to a teratogen that directly inhibits SMO reduces the penetrance and expressivity of birth defects in Mosmo−/− embryos. Additionally, tissues that develop normally in Mosmo−/− embryos are refractory to the teratogen. Thus, changes in the abundance of the protein target of a teratogen can change birth defect outcomes by quantitative shifts in Hh signaling. Consequently, small molecules that re-calibrate signaling strength could be harnessed to rescue structural birth defects.

scholarly journals Detection of Canonical Hedgehog Signaling in Breast Cancer by 131-Iodine-Labeled Derivatives of the Sonic Hedgehog Protein

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Jennifer Sims-Mourtada ◽  
David Yang ◽  
Izabela Tworowska ◽  
Richard Larson ◽  
Daniel Smith ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Hedgehog Signaling ◽  
Receptor Expression ◽  
Biodistribution Studies ◽  
Pathway Activation ◽  
Signaling Inhibitors ◽  
Gastrointestinal Tissue ◽  
Hh Signaling ◽  
Significant Uptake

Activation of hedgehog (HH) pathway signaling is observed in many tumors. Due to a feedback loop, the HH receptor Patched (PTCH-1) is overexpressed in tumors with activated HH signaling. Therefore, we sought to radiolabel the PTCH-1 ligand sonic (SHH) for detection of cancer cells with canonical HH activity. Receptor binding of131I-SHH was increased in cell lines with high HH pathway activation. Our findings also show that PTCH-1 receptor expression is decreased upon treatment with HH signaling inhibitors, and receptor binding of131I-SHH is significantly decreased following treatment with cyclopamine.In vivoimaging and biodistribution studies revealed significant accumulation of131I-SHH within tumor tissue as compared to normal organs. Tumor-to-muscle ratios were approximately 8 : 1 at 5 hours, while tumor to blood and tumor to bone were 2 : 1 and 5 : 1, respectively. Significant uptake was also observed in liver and gastrointestinal tissue. These studies show that131I-SHH is capable ofin vivodetection of breast tumors with high HH signaling. We further demonstrate that the hedgehog receptor PTCH-1 is downregulated upon treatment with hedgehog inhibitors. Our data suggests that radiolabeled SHH derivatives may provide a method to determine response to SHH-targeted therapies.

scholarly journals The novel ciliogenesis regulator DYRK2 governs Hedgehog signaling during mouse embryogenesis

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Saishu Yoshida ◽  
Katsuhiko Aoki ◽  
Ken Fujiwara ◽  
Takashi Nakakura ◽  
Akira Kawamura ◽  
...  
Keyword(s):  
Hedgehog Signaling ◽  
Primary Cilia ◽  
Molecular Mechanisms ◽  
The Novel ◽  
Mammalian Development ◽  
Hh Signaling ◽  
Functional Analyses ◽  
First Time ◽  
Insight Into

Mammalian Hedgehog (Hh) signaling plays key roles in embryogenesis and uniquely requires primary cilia. Functional analyses of several ciliogenesis-related genes led to the discovery of the developmental diseases known as ciliopathies. Hence, identification of mammalian factors that regulate ciliogenesis can provide insight into the molecular mechanisms of embryogenesis and ciliopathy. Here, we demonstrate that DYRK2 acts as a novel mammalian ciliogenesis-related protein kinase. Loss of Dyrk2 in mice causes suppression of Hh signaling and results in skeletal abnormalities during in vivo embryogenesis. Deletion of Dyrk2 induces abnormal ciliary morphology and trafficking of Hh pathway components. Mechanistically, transcriptome analyses demonstrate down-regulation of Aurka and other disassembly genes following Dyrk2 deletion. Taken together, the present study demonstrates for the first time that DYRK2 controls ciliogenesis and is necessary for Hh signaling during mammalian development.

scholarly journals Chondroitin sulfate proteoglycan Windpipe modulates Hedgehog signaling in Drosophila

2018 ◽  
Author(s):  
Masahiko Takemura ◽  
Fredrik Noborn ◽  
Jonas Nilsson ◽  
Eriko Nakato ◽  
Tsu-Yi Su ◽  
...  
Keyword(s):  
Cell Surface ◽  
Chondroitin Sulfate ◽  
Hedgehog Signaling ◽  
Transmembrane Protein ◽  
Wing Disc ◽  
Chondroitin Sulfate Proteoglycan ◽  
Growth Factor Signaling ◽  
Sulfate Proteoglycan ◽  
Sugar Chain ◽  
Hh Signaling

AbstractProteoglycans, a class of carbohydrate-modified proteins, often modulate growth factor signaling on the cell surface. However, the molecular mechanism by which proteoglycans regulate signal transduction is largely unknown. In this study, using a recently-developed glycoproteomic method, we found that Windpipe (Wdp) is a novel chondroitin sulfate proteoglycan (CSPG) in Drosophila. Wdp is a single-pass transmembrane protein with leucin-rich repeat (LRR) motifs and bears three CS sugar chain attachment sites in the extracellular domain. Here we show that Wdp modulates the Hedgehog (Hh) pathway. Overexpression of wdp inhibits Hh signaling in the wing disc, which is dependent on its CS chains and the LRR motifs. Conversely, loss of wdp leads to the upregulation of Hh signaling. Furthermore, knockdown of wdp increase the cell surface accumulation of Smoothened (Smo), suggesting that Wdp inhibits Hh signaling by regulating Smo stability. Our study demonstrates a novel role of CSPG in regulating Hh signaling.

Hedgehog Signaling Is Dispensable for Adult Murine Hematopoiesis and Leukemogenesis.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1391-1391
Author(s):  
Inga Hofmann Zhang ◽  
Elizabeth H. Stover ◽  
Dana E. Cullen ◽  
Junhao Mao ◽  
Kelly J. Morgan ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Cell Fate ◽  
Intracellular Signaling ◽  
Hedgehog Signaling ◽  
Unexpected Finding ◽  
Hematopoietic Stem ◽  
Developmental Abnormalities ◽  
Hh Signaling ◽  
Pharmacologic Inhibition

Abstract Hedgehog (Hh) pathway proteins are a highly conserved family of intracellular signaling molecules that are critical for the development of multiple organs and tissues, and play a role in cell fate determination of self-renewing tissues in the adult. Mutations that impair Hh signaling have been associated with developmental abnormalities, and recent studies indicate that Hh plays an important role in hemangioblast formation and in adult hematopoiesis, as well as in the differentiation and proliferation of hematopoietic stem cells (HSC) and progenitor cells. We used a genetic and pharmacologic approach to define the role of the Hh pathway in adult hematopoiesis and leukemogenesis. We report the unexpected finding that loss of Hh signaling through conditional deletion of Smoothened (Smo) in the adult hematopoietic compartment has no effect on adult hematopoiesis, including peripheral blood count, number or cell cycle status of stem and progenitor cells, hematopoietic colony forming potential, long-term repopulating activity in competitive repopulation assays, or stress-response to serial 5-fluorouracil treatment. In support of these observations based on genetic inactivation of the pathway, we observed that pharmacologic inhibition of Hh signaling with a potent and highly selective small molecule antagonist of Smo has no apparent effect on hematopoiesis in the mouse in vivo. In addition, we observed that Hh signaling is not required for the development of MLL-AF9 mediated leukemia. Taken together, these data indicate that Hh signaling is dispensable for normal hematopoietic development and leukemogenesis, and that pharmacologic inhibition of Hh signaling, as a therapeutic strategy in treatment of solid tumors with constitutive Hh pathway activation is not likely to be associated with unmanageable hematopoietic toxicity.

scholarly journals Endocannabinoids are conserved inhibitors of the Hedgehog pathway

2015 ◽  
Vol 112 (11) ◽  
pp. 3415-3420 ◽  
Author(s):  
Helena Khaliullina ◽  
Mesut Bilgin ◽  
Julio L. Sampaio ◽  
Andrej Shevchenko ◽  
Suzanne Eaton
Keyword(s):  
Mass Spectrometry ◽  
Hedgehog Signaling ◽  
Transmembrane Protein ◽  
Hedgehog Pathway ◽  
Tissue Development ◽  
Control Tissue ◽  
Lipid Mass ◽  
Biochemical Fractionation

Hedgehog ligands control tissue development and homeostasis by alleviating repression of Smoothened, a seven-pass transmembrane protein. The Hedgehog receptor, Patched, is thought to regulate the availability of small lipophilic Smoothened repressors whose identity is unknown. Lipoproteins contain lipids required to repress Smoothened signaling in vivo. Here, using biochemical fractionation and lipid mass spectrometry, we identify these repressors as endocannabinoids. Endocannabinoids circulate in human and Drosophila lipoproteins and act directly on Smoothened at physiological concentrations to repress signaling in Drosophila and mammalian assays. Phytocannabinoids are also potent Smo inhibitors. These findings link organismal metabolism to local Hedgehog signaling and suggest previously unsuspected mechanisms for the physiological activities of cannabinoids.

scholarly journals The Role of Small Molecules and Their Effect on the Molecular Mechanisms of Early Retinal Organoid Development

2021 ◽  
Vol 22 (13) ◽  
pp. 7081
Author(s):  
Philip E. Wagstaff ◽  
Andrea Heredero Berzal ◽  
Camiel J. F. Boon ◽  
Peter M. J. Quinn ◽  
Anneloor L. M. A. ten Asbroek ◽  
...  
Keyword(s):  
Small Molecules ◽  
Signaling Pathways ◽  
Hedgehog Signaling ◽  
Molecular Mechanisms ◽  
Retinal Development ◽  
Comprehensive Overview ◽  
Or Efficiency

Early in vivo embryonic retinal development is a well-documented and evolutionary conserved process. The specification towards eye development is temporally controlled by consecutive activation or inhibition of multiple key signaling pathways, such as the Wnt and hedgehog signaling pathways. Recently, with the use of retinal organoids, researchers aim to manipulate these pathways to achieve better human representative models for retinal development and disease. To achieve this, a plethora of different small molecules and signaling factors have been used at various time points and concentrations in retinal organoid differentiations, with varying success. Additions differ from protocol to protocol, but their usefulness or efficiency has not yet been systematically reviewed. Interestingly, many of these small molecules affect the same and/or multiple pathways, leading to reduced reproducibility and high variability between studies. In this review, we make an inventory of the key signaling pathways involved in early retinogenesis and their effect on the development of the early retina in vitro. Further, we provide a comprehensive overview of the small molecules and signaling factors that are added to retinal organoid differentiation protocols, documenting the molecular and functional effects of these additions. Lastly, we comparatively evaluate several of these factors using our established retinal organoid methodology.

scholarly journals Hedgehog signaling activates a heterochronic gene regulatory network to control differentiation timing across lineages

2018 ◽  
Author(s):  
Megan Rowton ◽  
Carlos Perez-Cervantes ◽  
Ariel Rydeen ◽  
Suzy Hur ◽  
Jessica Jacobs-Li ◽  
...  
Keyword(s):  
Gene Regulatory Network ◽  
Regulatory Network ◽  
Hedgehog Signaling ◽  
Cardiomyocyte Differentiation ◽  
Cardiac Progenitors ◽  
Second Heart Field ◽  
Heart Field ◽  
Gene Regulatory ◽  
Hh Signaling

SUMMARYHeterochrony, defined as differences in the timing of developmental processes, impacts organ development, homeostasis, and regeneration. The molecular basis of heterochrony in mammalian tissues is poorly understood. We report that Hedgehog signaling activates a heterochronic pathway that controls differentiation timing in multiple lineages. A differentiation trajectory from second heart field cardiac progenitors to first heart field cardiomyocytes was identified by single-cell transcriptional profiling in mouse embryos. A survey of developmental signaling pathways revealed specific enrichment for Hedgehog signaling targets in cardiac progenitors. Removal of Hh signaling caused loss of progenitor and precocious cardiomyocyte differentiation gene expression in the second heart field in vivo. Introduction of active Hh signaling to mESC-derived progenitors, modelled by transient expression of the Hh-dependent transcription factor GLI1, delayed differentiation in cardiac and neural lineages in vitro. A shared GLI1-dependent network in both cardiac and neural progenitors was enriched with FOX family transcription factors. FOXF1, a GLI1 target, was sufficient to delay onset of the cardiomyocyte differentiation program in progenitors, by epigenetic repression of cardiomyocyte-specific enhancers. Removal of active Hh signaling or Foxf1 expression from second heart field progenitors caused precocious cardiac differentiation in vivo, establishing a mechanism for resultant Congenital Heart Disease. Together, these studies suggest that Hedgehog signaling directly activates a gene regulatory network that functions as a heterochronic switch to control differentiation timing across developmental lineages.

scholarly journals Biphasic roles of hedgehog signaling in the production and self-renewal of outer radial glia in the ferret cerebral cortex

2021 ◽  
Author(s):  
Shirui Hou ◽  
Wan-Ling Ho ◽  
Lei Wang ◽  
Bryan Kuo ◽  
Jun Young Park ◽  
...  
Keyword(s):  
Hedgehog Signaling ◽  
Radial Glia ◽  
Superficial Layer ◽  
Cellular Mechanisms ◽  
Self Renewal ◽  
Layer Neuron ◽  
Outer Radial Glia ◽  
Hh Signaling ◽  
Necessary And Sufficient

The neocortex, the center for higher brain function, emerged in mammals and expanded in the course of evolution. The expansion of outer radial glia (oRGs) and intermediate progenitor cells (IPCs) plays key roles in the expansion and consequential folding of the neocortex. Therefore, understanding the mechanisms of oRG and IPC expansion is important for understanding neocortical development and evolution. By using mice and human cerebral organoids, we previously revealed that hedgehog (HH) signaling expands oRGs and IPCs. Nevertheless, it remained to be determined whether HH signaling expanded oRGs and IPCs in vivo in gyrencephalic species, in which oRGs and IPCs are naturally expanded. Here, we show that HH signaling is necessary and sufficient to expand oRGs and IPCs in ferrets, a gyrencephalic species, through conserved cellular mechanisms. HH signaling increases oRG-producing division modes of ventricular radial glia (vRGs), oRG self-renewal, and IPC proliferation. Notably, HH signaling affects vRG division modes only in an early restricted phase before superficial-layer neuron production peaks. Beyond this restricted phase, HH signaling promotes oRG self-renewal. Thus, HH signaling expands oRGs and IPCs in two distinct but continuous phases during cortical development.

scholarly journals AICD Overexpression in Neuro 2A Cells Regulates Expression of PTCH1 and TRPC5

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Mithu Raychaudhuri ◽  
Debashis Mukhopadhyay
Keyword(s):  
Hedgehog Signaling ◽  
Transient Receptor Potential ◽  
Transmembrane Protein ◽  
Neuroblastoma Cell ◽  
Receptor Potential ◽  
Cation Channel ◽  
Gamma Secretase ◽  
Sonic Hedgehog Signaling

Amyloid precursor protein (APP), implicated in Alzheimer's disease, is a transmembrane protein of undetermined function. APP is cleaved by gamma-secretase that releases the APP intracellular domain (AICD) in the cytoplasm.In vitroandin vivostudies have implicated the role of AICD in cell signaling and transcriptional regulation of Gsk3β, KAI1, BACE1, EGFR, and other proteins. In this study, by overexpressing AICD in mouse neuroblastoma cell lines, we have demonstrated the alteration in the expressions of two proteins, patched homolog 1 (PTCH1), a receptor for sonic hedgehog signaling, and transient receptor potential cation channel subfamily C member 5 (TRPC5), a component of receptor-activated nonselective calcium permeant cation channel. Our results indicate the possibility of regulation by AICD in developmental processes as well as in the maintenance of calcium homeostasis at the transcription level.

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