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Sample records for constitutive hedgehog signaling

  1. [Primary cilia and hedgehog signaling].

    PubMed

    Fujii, Katsunori

    2015-07-01

    The primary cilium is an immotile organelle protruding from the cell surface in almost all vertebrate cells. Many molecules inside the primary cilia coordinately play a pivotal role, so genetic defects of these components result in diverse congenital malformations of the brain, eye, liver, kidney, and skeleton. Hedgehog signaling is a highly conserved pathway regulating morphogenesis in early development and tumorigenesis postnatally. Recently, advanced molecular biology has revealed that components of hedgehog signaling such as PTCH1, SMO, and GLI specifically translocate within the primary cilium upon the ligand binding of the hedgehog protein, and transduce the biological growth signal from the cell surface to the nucleus. Haploinsufficiency of the components in the primary cilium would inhibit the hedgehog pathway, resulting in developmental anomalies like ventral neural tube defects. Since the hedgehog-dependent pathway is critical for vertebrate development, it is crucial to elucidate the functional roles of hedgehog-related proteins in the primary cilium. PMID:26353446

  2. Inhibitors of Hedgehog acyltransferase block Sonic Hedgehog signaling.

    PubMed

    Petrova, Elissaveta; Rios-Esteves, Jessica; Ouerfelli, Ouathek; Glickman, J Fraser; Resh, Marilyn D

    2013-04-01

    Inhibition of Sonic hedgehog (Shh) signaling is of great clinical interest. Here we exploit Hedgehog acyltransferase (Hhat)-mediated Shh palmitoylation, a modification critical for Shh signaling, as a new target for Shh pathway inhibition. A target-oriented high-throughput screen was used to identify small-molecule inhibitors of Hhat. In cells, these Hhat inhibitors specifically block Shh palmitoylation and inhibit autocrine and paracrine Shh signaling.

  3. Inhibitors of Hedgehog acyltransferase block Sonic Hedgehog signaling.

    PubMed

    Petrova, Elissaveta; Rios-Esteves, Jessica; Ouerfelli, Ouathek; Glickman, J Fraser; Resh, Marilyn D

    2013-04-01

    Inhibition of Sonic hedgehog (Shh) signaling is of great clinical interest. Here we exploit Hedgehog acyltransferase (Hhat)-mediated Shh palmitoylation, a modification critical for Shh signaling, as a new target for Shh pathway inhibition. A target-oriented high-throughput screen was used to identify small-molecule inhibitors of Hhat. In cells, these Hhat inhibitors specifically block Shh palmitoylation and inhibit autocrine and paracrine Shh signaling. PMID:23416332

  4. The Hedgehog Signal Transduction Network

    PubMed Central

    Robbins, David J.; Fei, Dennis Liang; Riobo, Natalia A.

    2013-01-01

    Hedgehog (Hh) proteins regulate the development of a wide range of metazoan embryonic and adult structures, and disruption of Hh signaling pathways results in various human diseases. Here, we provide a comprehensive review of the signaling pathways regulated by Hh, consolidating data from a diverse array of organisms in a variety of scientific disciplines. Similar to the elucidation of many other signaling pathways, our knowledge of Hh signaling developed in a sequential manner centered on its earliest discoveries. Thus, our knowledge of Hh signaling has for the most part focused on elucidating the mechanism by which Hh regulates the Gli family of transcription factors, the so-called “canonical” Hh signaling pathway. However, in the past few years, numerous studies have shown that Hh proteins can also signal through Gli-independent mechanisms collectively referred to as “noncanonical” signaling pathways. Noncanonical Hh signaling is itself subdivided into two distinct signaling modules: (i) those not requiring Smoothened (Smo) and (ii) those downstream of Smo that do not require Gli transcription factors. Thus, Hh signaling is now proposed to occur through a variety of distinct context-dependent signaling modules that have the ability to crosstalk with one another to form an interacting, dynamic Hh signaling network. PMID:23074268

  5. Hedgehog Signaling in Pancreatic Fibrosis and Cancer

    PubMed Central

    Bai, Yongyu; Bai, Yongheng; Dong, Jiaojiao; Li, Qiang; Jin, Yuepeng; Chen, Bicheng; Zhou, Mengtao

    2016-01-01

    Abstract The hedgehog signaling pathway was first discovered in the 1980s. It is a stem cell-related pathway that plays a crucial role in embryonic development, tissue regeneration, and organogenesis. Aberrant activation of hedgehog signaling leads to pathological consequences, including a variety of human tumors such as pancreatic cancer. Multiple lines of evidence indicate that blockade of this pathway with several small-molecule inhibitors can inhibit the development of pancreatic neoplasm. In addition, activated hedgehog signaling has been reported to be involved in fibrogenesis in many tissues, including the pancreas. Therefore, new therapeutic targets based on hedgehog signaling have attracted a great deal of attention to alleviate pancreatic diseases. In this review, we briefly discuss the recent advances in hedgehog signaling in pancreatic fibrogenesis and carcinogenesis and highlight new insights on their potential relationship with respect to the development of novel targeted therapies. PMID:26962810

  6. Hedgehog Signaling in Pancreatic Fibrosis and Cancer.

    PubMed

    Bai, Yongyu; Bai, Yongheng; Dong, Jiaojiao; Li, Qiang; Jin, Yuepeng; Chen, Bicheng; Zhou, Mengtao

    2016-03-01

    The hedgehog signaling pathway was first discovered in the 1980s. It is a stem cell-related pathway that plays a crucial role in embryonic development, tissue regeneration, and organogenesis. Aberrant activation of hedgehog signaling leads to pathological consequences, including a variety of human tumors such as pancreatic cancer. Multiple lines of evidence indicate that blockade of this pathway with several small-molecule inhibitors can inhibit the development of pancreatic neoplasm. In addition, activated hedgehog signaling has been reported to be involved in fibrogenesis in many tissues, including the pancreas. Therefore, new therapeutic targets based on hedgehog signaling have attracted a great deal of attention to alleviate pancreatic diseases. In this review, we briefly discuss the recent advances in hedgehog signaling in pancreatic fibrogenesis and carcinogenesis and highlight new insights on their potential relationship with respect to the development of novel targeted therapies. PMID:26962810

  7. Hedgehog Cholesterolysis: Specialized Gatekeeper to Oncogenic Signaling

    PubMed Central

    Callahan, Brian P.; Wang, Chunyu

    2015-01-01

    Discussions of therapeutic suppression of hedgehog (Hh) signaling almost exclusively focus on receptor antagonism; however, hedgehog’s biosynthesis represents a unique and potentially targetable aspect of this oncogenic signaling pathway. Here, we review a key biosynthetic step called cholesterolysis from the perspectives of structure/function and small molecule inhibition. Cholesterolysis, also called cholesteroylation, generates cholesterol-modified Hh ligand via autoprocessing of a hedgehog precursor protein. Post-translational modification by cholesterol appears to be restricted to proteins in the hedgehog family. The transformation is essential for Hh biological activity and upstream of signaling events. Despite its decisive role in generating ligand, cholesterolysis remains conspicuously unexplored as a therapeutic target. PMID:26473928

  8. The Hedgehog signalling pathway in bone formation

    PubMed Central

    Yang, Jing; Andre, Philipp; Ye, Ling; Yang, Ying-Zi

    2015-01-01

    The Hedgehog (Hh) signalling pathway plays many important roles in development, homeostasis and tumorigenesis. The critical function of Hh signalling in bone formation has been identified in the past two decades. Here, we review the evolutionarily conserved Hh signalling mechanisms with an emphasis on the functions of the Hh signalling pathway in bone development, homeostasis and diseases. In the early stages of embryonic limb development, Sonic Hedgehog (Shh) acts as a major morphogen in patterning the limb buds. Indian Hedgehog (Ihh) has an essential function in endochondral ossification and induces osteoblast differentiation in the perichondrium. Hh signalling is also involved intramembrane ossification. Interactions between Hh and Wnt signalling regulate cartilage development, endochondral bone formation and synovial joint formation. Hh also plays an important role in bone homeostasis, and reducing Hh signalling protects against age-related bone loss. Disruption of Hh signalling regulation leads to multiple bone diseases, such as progressive osseous heteroplasia. Therefore, understanding the signalling mechanisms and functions of Hh signalling in bone development, homeostasis and diseases will provide important insights into bone disease prevention, diagnoses and therapeutics. PMID:26023726

  9. Hedgehog Signalling in the Embryonic Mouse Thymus

    PubMed Central

    Saldaña, José Ignacio; Crompton, Tessa

    2016-01-01

    T cells develop in the thymus, which provides an essential environment for T cell fate specification, and for the differentiation of multipotent progenitor cells into major histocompatibility complex (MHC)-restricted, non-autoreactive T cells. Here we review the role of the Hedgehog signalling pathway in T cell development, thymic epithelial cell (TEC) development, and thymocyte–TEC cross-talk in the embryonic mouse thymus during the last week of gestation. PMID:27504268

  10. Hedgehog Secretion and Signal Transduction in Vertebrates

    PubMed Central

    Ryan, Kaitlyn E.; Chiang, Chin

    2012-01-01

    Signaling by the Hedgehog (Hh) family of secreted proteins is essential for proper embryonic patterning and development. Dysregulation of Hh signaling is associated with a variety of human diseases ranging from developmental disorders such as holoprosencephaly to certain forms of cancer, including medulloblastoma and basal cell carcinoma. Genetic studies in flies and mice have shaped our understanding of Hh signaling and revealed that nearly all core components of the pathway are highly conserved. Although many aspects of the Drosophila Hh pathway are conserved in vertebrates, mechanistic differences between the two species have begun to emerge. Perhaps the most striking divergence in vertebrate Hh signaling is its dependence on the primary cilium, a vestigial organelle that is largely absent in flies. This minireview will provide an overview of Hh signaling and present recent insights into vertebrate Hh secretion, receptor binding, and signal transduction. PMID:22474285

  11. The role of glypicans in Hedgehog signaling.

    PubMed

    Filmus, Jorge; Capurro, Mariana

    2014-04-01

    Glypicans (GPCs) are a family of proteoglycans that are bound to the cell surface by a glycosylphosphatidylinositol anchor. Six glypicans have been found in the mammalian genome (GPC1 to GPC6). GPCs regulate several signaling pathways, including the pathway triggered by Hedgehogs (Hhs). This regulation, which could be stimulatory or inhibitory, occurs at the signal reception level. In addition, GPCs have been shown to be involved in the formation of Hh gradients in the imaginal wing disks in Drosophila. In this review we will discuss the role of various glypicans in specific developmental events in the embryo that are regulated by Hh signaling. In addition, we will discuss the mechanism by which loss-of-function GPC3 mutations alter Hh signaling in the Simpson-Golabi-Behmel overgrowth syndrome, and the molecular basis of the GPC5-induced stimulation of Hh signaling and tumor progression in rhabdomyosarcomas. PMID:24412155

  12. Hedgehog Signaling during Appendage Development and Regeneration.

    PubMed

    Singh, Bhairab N; Koyano-Nakagawa, Naoko; Donaldson, Andrew; Weaver, Cyprian V; Garry, Mary G; Garry, Daniel J

    2015-01-01

    Regulatory networks that govern embryonic development have been well defined. While a common hypothesis supports the notion that the embryonic regulatory cascades are reexpressed following injury and tissue regeneration, the mechanistic regulatory pathways that mediate the regenerative response in higher organisms remain undefined. Relative to mammals, lower vertebrates, including zebrafish and newts, have a tremendous regenerative capacity to repair and regenerate a number of organs including: appendages, retina, heart, jaw and nervous system. Elucidation of the pathways that govern regeneration in these lower organisms may provide cues that will enhance the capacity for the regeneration of mammalian organs. Signaling pathways, such as the hedgehog pathway, have been shown to play critical functions during development and during regeneration in lower organisms. These signaling pathways have been shown to modulate multiple processes including cellular origin, positional identity and cellular maturation. The present review will focus on the cellular and molecular regulation of the hedgehog (HH) signaling pathway and its interaction with other signaling factors during appendage development and regeneration. PMID:26110318

  13. Hedgehog Signaling during Appendage Development and Regeneration

    PubMed Central

    Singh, Bhairab N.; Koyano-Nakagawa, Naoko; Donaldson, Andrew; Weaver, Cyprian V.; Garry, Mary G.; Garry, Daniel J.

    2015-01-01

    Regulatory networks that govern embryonic development have been well defined. While a common hypothesis supports the notion that the embryonic regulatory cascades are reexpressed following injury and tissue regeneration, the mechanistic regulatory pathways that mediate the regenerative response in higher organisms remain undefined. Relative to mammals, lower vertebrates, including zebrafish and newts, have a tremendous regenerative capacity to repair and regenerate a number of organs including: appendages, retina, heart, jaw and nervous system. Elucidation of the pathways that govern regeneration in these lower organisms may provide cues that will enhance the capacity for the regeneration of mammalian organs. Signaling pathways, such as the hedgehog pathway, have been shown to play critical functions during development and during regeneration in lower organisms. These signaling pathways have been shown to modulate multiple processes including cellular origin, positional identity and cellular maturation. The present review will focus on the cellular and molecular regulation of the hedgehog (HH) signaling pathway and its interaction with other signaling factors during appendage development and regeneration. PMID:26110318

  14. [Hedgehog signaling in the pathogenesis of neuro-oncology diseases].

    PubMed

    Cherepanov, S A; Baklaushev, V P; Gabashvili, A N; Shepeleva, I I; Chekhonin, V P

    2015-01-01

    The review summarizes current knowledge on the Hedgehog signaling pathway, its role in normal embryogenesis and/or initiation and progression of neuro-oncological diseases, especially of high-grade gliomas, the most malignant neuroepithelial tumors. The main proteins forming the Hedgehog signaling pathway include Shh, PTCH1, SMO, HHIP, SUFU and GLI1 isoforms. Effects of other signaling pathways on the family of transcription factors GLI and other proteins are described. The review summarizes modern data about the impact of the Hedgehog signaling pathway on proliferation, migration activity and invasiveness, and also on tumor neoangiogenesis and tumor cell chemoresistance. The role of the Hedgehog signaling pathway in origin of cancer stem cells and epithelial-mesenchymal transition is also analyzed. Some prospects for new anticancer drugs acting on components of the Hedgehog signaling pathway inhibitors are demonstrated. PMID:26215410

  15. Protein kinase A activity and Hedgehog signaling pathway.

    PubMed

    Kotani, Tomoya

    2012-01-01

    Protein kinase A (PKA) is a well-known kinase that plays fundamental roles in a variety of biological processes. In Hedgehog-responsive cells, PKA plays key roles in proliferation and fate specification by modulating the transduction of Hedgehog signaling. In the absence of Hedgehog, a basal level of PKA activity represses the transcription of Hedgehog target genes. The main substrates of PKA in this process are the Ci/Gli family of bipotential transcription factors, which activate and repress Hedgehog target gene expression. PKA phosphorylates Ci/Gli, promoting the production of the repressor forms of Ci/Gli and thus repressing Hedgehog target gene expression. In contrast, the activation of Hedgehog signaling in response to Hedgehog increases the active forms of Ci/Gli, resulting in Hedgehog target gene expression. Because both decreased and increased levels of PKA activity cause abnormal cell proliferation and alter cell fate specification, the basal level of PKA activity in Hedgehog-responsive cells should be precisely regulated. However, the mechanism by which PKA activity is regulated remains obscure and appears to vary between cell types, tissues, and organisms. To date, two mechanisms have been proposed. One is a classical mechanism in which PKA activity is regulated by a small second messenger, cAMP; the other is a novel mechanism in which PKA activity is regulated by a protein, Misty somites. PMID:22391308

  16. Hedgehog signalling in the mouse requires intraflagellar transport proteins.

    PubMed

    Huangfu, Danwei; Liu, Aimin; Rakeman, Andrew S; Murcia, Noel S; Niswander, Lee; Anderson, Kathryn V

    2003-11-01

    Intraflagellar transport (IFT) proteins were first identified as essential factors for the growth and maintenance of flagella in the single-celled alga Chlamydomonas reinhardtii. In a screen for embryonic patterning mutations induced by ethylnitrosourea, here we identify two mouse mutants, wimple (wim) and flexo (fxo), that lack ventral neural cell types and show other phenotypes characteristic of defects in Sonic hedgehog signalling. Both mutations disrupt IFT proteins: the wim mutation is an allele of the previously uncharacterized mouse homologue of IFT172; and fxo is a new hypomorphic allele of polaris, the mouse homologue of IFT88. Genetic analysis shows that Wim, Polaris and the IFT motor protein Kif3a are required for Hedgehog signalling at a step downstream of Patched1 (the Hedgehog receptor) and upstream of direct targets of Hedgehog signalling. Our data show that IFT machinery has an essential and vertebrate-specific role in Hedgehog signal transduction. PMID:14603322

  17. Sex and hedgehog: roles of genes in the hedgehog signaling pathway in mammalian sexual differentiation.

    PubMed

    Franco, Heather L; Yao, Humphrey H-C

    2012-01-01

    The chromosome status of the mammalian embryo initiates a multistage process of sexual development in which the bipotential reproductive system establishes itself as either male or female. These events are governed by intricate cell-cell and interorgan communication that is regulated by multiple signaling pathways. The hedgehog signaling pathway was originally identified for its key role in the development of Drosophila, but is now recognized as a critical developmental regulator in many species, including humans. In addition to its developmental roles, the hedgehog signaling pathway also modulates adult organ function, and misregulation of this pathway often leads to diseases, such as cancer. The hedgehog signaling pathway acts through its morphogenetic ligands that signal from ligand-producing cells to target cells over a specified distance. The target cells then respond in a graded manner based on the concentration of the ligands that they are exposed to. Through this unique mechanism of action, the hedgehog signaling pathway elicits cell fate determination, epithelial-mesenchymal interactions, and cellular homeostasis. Here, we review current findings on the roles of hedgehog signaling in the sexually dimorphic development of the reproductive organs with an emphasis on mammals and comparative evidence in other species.

  18. dachshund Potentiates Hedgehog Signaling during Drosophila Retinogenesis

    PubMed Central

    Aerts, Stein; Casares, Fernando; Janody, Florence

    2016-01-01

    Proper organ patterning depends on a tight coordination between cell proliferation and differentiation. The patterning of Drosophila retina occurs both very fast and with high precision. This process is driven by the dynamic changes in signaling activity of the conserved Hedgehog (Hh) pathway, which coordinates cell fate determination, cell cycle and tissue morphogenesis. Here we show that during Drosophila retinogenesis, the retinal determination gene dachshund (dac) is not only a target of the Hh signaling pathway, but is also a modulator of its activity. Using developmental genetics techniques, we demonstrate that dac enhances Hh signaling by promoting the accumulation of the Gli transcription factor Cubitus interruptus (Ci) parallel to or downstream of fused. In the absence of dac, all Hh-mediated events associated to the morphogenetic furrow are delayed. One of the consequences is that, posterior to the furrow, dac- cells cannot activate a Roadkill-Cullin3 negative feedback loop that attenuates Hh signaling and which is necessary for retinal cells to continue normal differentiation. Therefore, dac is part of an essential positive feedback loop in the Hh pathway, guaranteeing the speed and the accuracy of Drosophila retinogenesis. PMID:27442438

  19. Cellular Cholesterol Directly Activates Smoothened in Hedgehog Signaling.

    PubMed

    Huang, Pengxiang; Nedelcu, Daniel; Watanabe, Miyako; Jao, Cindy; Kim, Youngchang; Liu, Jing; Salic, Adrian

    2016-08-25

    In vertebrates, sterols are necessary for Hedgehog signaling, a pathway critical in embryogenesis and cancer. Sterols activate the membrane protein Smoothened by binding its extracellular, cysteine-rich domain (CRD). Major unanswered questions concern the nature of the endogenous, activating sterol and the mechanism by which it regulates Smoothened. We report crystal structures of CRD complexed with sterols and alone, revealing that sterols induce a dramatic conformational change of the binding site, which is sufficient for Smoothened activation and is unique among CRD-containing receptors. We demonstrate that Hedgehog signaling requires sterol binding to Smoothened and define key residues for sterol recognition and activity. We also show that cholesterol itself binds and activates Smoothened. Furthermore, the effect of oxysterols is abolished in Smoothened mutants that retain activation by cholesterol and Hedgehog. We propose that the endogenous Smoothened activator is cholesterol, not oxysterols, and that vertebrate Hedgehog signaling controls Smoothened by regulating its access to cholesterol. PMID:27545348

  20. Intricacies of hedgehog signaling pathways: A perspective in tumorigenesis

    SciTech Connect

    Kar, Swayamsiddha; Deb, Moonmoon; Sengupta, Dipta; Shilpi, Arunima; Bhutia, Sujit Kumar; Patra, Samir Kumar

    2012-10-01

    The hedgehog (HH) signaling pathway is a crucial negotiator of developmental proceedings in the embryo governing a diverse array of processes including cell proliferation, differentiation, and tissue patterning. The overall activity of the pathway is significantly curtailed after embryogenesis as well as in adults, yet it retains many of its functional capacities. However, aberration in HH signaling mediates the initiation, proliferation and continued sustenance of malignancy in different tissues to varying degrees through different mechanisms. In this review, we provide an overview of the role of constitutively active aberrant HH signaling pathway in different types of human cancer and the underlying molecular and genetic mechanisms that drive tumorigenesis in that particular tissue. An insight into the various modes of anomalous HH signaling in different organs will provide a comprehensive knowledge of the pathway in these tissues and open a window for individually tailored, tissue-specific therapeutic interventions. The synergistic cross talking of HH pathway with many other regulatory molecules and developmentally inclined signaling pathways may offer many avenues for pharmacological advances. Understanding the molecular basis of abnormal HH signaling in cancer will provide an opportunity to inhibit the deregulated pathway in many aggressive and therapeutically challenging cancers where promising options are not available.

  1. Hedgehog signaling in the normal and neoplastic mammary gland.

    PubMed

    Visbal, Adriana P; Lewis, Michael T

    2010-09-01

    The hedgehog signal transduction network is a critical regulator of metazoan development. Inappropriate activation of this network is implicated in several different cancers, including breast. Genetic evidence in mice as well as molecular biological studies in human cells clearly indicate that activated signaling can lead to mammary hyperplasia and, in some cases, tumor formation. However, the exact role(s) activated hedgehog signaling plays in the development or progression of breast cancer also remain unclear. In this review, we have discussed recent data regarding the mechanism(s) by which the hedgehog network may signal in the mammary gland, as well as the data implicating activated signaling as a contributing factor to breast cancer development. Finally, we provide a brief update on the available hedgehog signaling inhibitors with respect to ongoing clinical trials, some of which will include locally advanced or metastatic breast cancers. Given the growing intensity with which the hedgehog signaling network is being studied in the normal and neoplastic mammary gland, a more complete understanding of this network should allow more effective targeting of its activities in breast cancer treatment or prevention.

  2. Expression pattern of the Hedgehog signaling pathway in pituitary adenomas.

    PubMed

    Yavropoulou, Maria P; Maladaki, Anna; Topouridou, Konstantina; Kotoula, Vasiliki; Poulios, Chris; Daskalaki, Emily; Foroglou, Nikolaos; Karkavelas, George; Yovos, John G

    2016-01-12

    Several studies have demonstrated the role of Wnt and Notch signaling in the pathogenesis of pituitary adenomas, but data are scarce regarding the role of Hedgehog signaling. In this study we investigated the differential expression of gene targets of the Hedgehog signaling pathway. Formalin-fixed, paraffin-embedded specimens from adult patients who underwent transphenoidal resection and normal human pituitary tissues that were obtained from autopsies were used. Clinical information and data from pre-operative MRI scan (extracellular tumor extension, tumor size, displacement of the optic chiasm) were retrieved from the Hospital's database. We used a customized RT(2) Profiler PCR Array, to investigate the expression of genes related to Notch and Hedgehog signaling pathways (PTCH1, PTCH2, GLI1, GLI3, NOTCH3, JAG1, HES1, and HIP). A total of 52 pituitary adenomas (32 non-functioning adenomas, 15 somatotropinomas and 5 prolactinomas) were used in the final analysis. In non-functioning pituitary adenomas there was a significant decrease (approximately 75%) in expression of all Hedgehog related genes that were tested, while Notch3 and Jagged-1 expression was found significantly increased, compared with normal pituitary tissue controls. In contrast, somatotropinomas demonstrated a significant increase in expression of all Hedgehog related genes and a decrease in the expression of Notch3 and Jagged-1. There was no significant difference in the expression of Hedgehog and Notch related genes between prolactinomas and healthy pituitary tissues. Hedgehog signalling appears to be activated in somatotropinomas but not in non-functioning pituitary adenomas in contrast to the expression pattern of Notch signalling pathway. PMID:26620835

  3. An Nfic-hedgehog signaling cascade regulates tooth root development.

    PubMed

    Liu, Yang; Feng, Jifan; Li, Jingyuan; Zhao, Hu; Ho, Thach-Vu; Chai, Yang

    2015-10-01

    Coordination between the Hertwig's epithelial root sheath (HERS) and apical papilla (AP) is crucial for proper tooth root development. The hedgehog (Hh) signaling pathway and Nfic are both involved in tooth root development; however, their relationship has yet to be elucidated. Here, we establish a timecourse of mouse molar root development by histological staining of sections, and we demonstrate that Hh signaling is active before and during root development in the AP and HERS using Gli1 reporter mice. The proper pattern of Hh signaling activity in the AP is crucial for the proliferation of dental mesenchymal cells, because either inhibition with Hh inhibitors or constitutive activation of Hh signaling activity in transgenic mice leads to decreased proliferation in the AP and shorter roots. Moreover, Hh activity is elevated in Nfic(-/-) mice, a root defect model, whereas RNA sequencing and in situ hybridization show that the Hh attenuator Hhip is downregulated. ChIP and RNAscope analyses suggest that Nfic binds to the promoter region of Hhip. Treatment of Nfic(-/-) mice with Hh inhibitor partially restores cell proliferation, AP growth and root development. Taken together, our results demonstrate that an Nfic-Hhip-Hh signaling pathway is crucial for apical papilla growth and proper root formation. This discovery provides insight into the molecular mechanisms regulating tooth root development.

  4. An Nfic-hedgehog signaling cascade regulates tooth root development

    PubMed Central

    Liu, Yang; Feng, Jifan; Li, Jingyuan; Zhao, Hu; Ho, Thach-Vu; Chai, Yang

    2015-01-01

    Coordination between the Hertwig's epithelial root sheath (HERS) and apical papilla (AP) is crucial for proper tooth root development. The hedgehog (Hh) signaling pathway and Nfic are both involved in tooth root development; however, their relationship has yet to be elucidated. Here, we establish a timecourse of mouse molar root development by histological staining of sections, and we demonstrate that Hh signaling is active before and during root development in the AP and HERS using Gli1 reporter mice. The proper pattern of Hh signaling activity in the AP is crucial for the proliferation of dental mesenchymal cells, because either inhibition with Hh inhibitors or constitutive activation of Hh signaling activity in transgenic mice leads to decreased proliferation in the AP and shorter roots. Moreover, Hh activity is elevated in Nfic−/− mice, a root defect model, whereas RNA sequencing and in situ hybridization show that the Hh attenuator Hhip is downregulated. ChIP and RNAscope analyses suggest that Nfic binds to the promoter region of Hhip. Treatment of Nfic−/− mice with Hh inhibitor partially restores cell proliferation, AP growth and root development. Taken together, our results demonstrate that an Nfic-Hhip-Hh signaling pathway is crucial for apical papilla growth and proper root formation. This discovery provides insight into the molecular mechanisms regulating tooth root development. PMID:26293299

  5. Deciphering the role of hedgehog signaling in pancreatic cancer

    PubMed Central

    Gu, Dongsheng; Schlotman, Kelly E; Xie, Jingwu

    2016-01-01

    Abstract Pancreatic cancer, mostly pancreatic ductal adenocarcinoma (PDAC), is a leading cause of cancer-related death in the US, with a dismal median survival of 6 months. Thus, there is an urgent unmet need to identify ways to diagnose and to treat this deadly cancer. Although a number of genetic changes have been identified in pancreatic cancer, their mechanisms of action in tumor development, progression and metastasis are not completely understood. Hedgehog signaling, which plays a major role in embryonic development and stem cell regulation, is known to be activated in pancreatic cancer; however, specific inhibitors targeting the smoothened molecule failed to improve the condition of pancreatic cancer patients in clinical trials. Furthermore, results regarding the role of Hh signaling in pancreatic cancer are controversial with some reporting tumor promoting activities whereas others tumor suppressive actions. In this review, we will summarize what we know about hedgehog signaling in pancreatic cancer, and try to explain the contradicting roles of hedgehog signaling as well as the reason(s) behind the failed clinical trials. In addition to the canonical hedgehog signaling, we will also discuss several non-canonical hedgehog signaling mechanisms. PMID:27346466

  6. Lithium chloride modulates chondrocyte primary cilia and inhibits Hedgehog signaling.

    PubMed

    Thompson, Clare L; Wiles, Anna; Poole, C Anthony; Knight, Martin M

    2016-02-01

    Lithium chloride (LiCl) exhibits significant therapeutic potential as a treatment for osteoarthritis. Hedgehog signaling is activated in osteoarthritis, where it promotes chondrocyte hypertrophy and cartilage matrix catabolism. Hedgehog signaling requires the primary cilium such that maintenance of this compartment is essential for pathway activity. Here we report that LiCl (50 mM) inhibits Hedgehog signaling in bovine articular chondrocytes such that the induction of GLI1 and PTCH1 expression is reduced ​ by 71 and 55%, respectively. Pathway inhibition is associated with a 97% increase in primary cilia length from 2.09 ± 0.7 μm in untreated cells to 4.06 ± 0.9 μm in LiCl-treated cells. We show that cilia elongation disrupts trafficking within the axoneme with a 38% reduction in Arl13b ciliary localization at the distal region of the cilium, consistent with the role of Arl13b in modulating Hedgehog signaling. In addition, we demonstrate similar increases in cilia length in human chondrocytes in vitro and after administration of dietary lithium to Wistar rats in vivo. Our data provide new insights into the effects of LiCl on chondrocyte primary cilia and Hedgehog signaling and shows for the first time that pharmaceutical targeting of the primary cilium may have therapeutic benefits in the treatment of osteoarthritis. PMID:26499268

  7. Piperazic acid derivatives inhibit Gli1 in Hedgehog signaling pathway.

    PubMed

    Khatra, Harleen; Kundu, Jayanta; Khan, Pragya Paramita; Duttagupta, Indranil; Pattanayak, Sankha; Sinha, Surajit

    2016-09-15

    Piperazic acid, a non-proteinogenic amino acid, found in complex secondary metabolites and peptide natural substances, has shown down regulation of Gli1 expression in Hedgehog signaling pathway in cell based assays. Further structure activity relationship study indicated that amide derivatives of piperazic acid are more potent than piperazic acid itself, with little to no toxicity. However, other cellular components involved in the pathway were not affected. To the best of our knowledge, this is the first report on the inhibitory property of piperazic acid in this pathway. Hence, this molecule could serve as a useful tool for studying Hedgehog signaling. PMID:27528433

  8. Skinny hedgehog, an acyltransferase required for palmitoylation and activity of the hedgehog signal.

    PubMed

    Chamoun, Z; Mann, R K; Nellen, D; von Kessler, D P; Bellotto, M; Beachy, P A; Basler, K

    2001-09-14

    One of the most dominant influences in the patterning of multicellular embryos is exerted by the Hedgehog (Hh) family of secreted signaling proteins. Here, we identify a segment polarity gene in Drosophila melanogaster, skinny hedgehog (ski), and show that its product is required in Hh-expressing cells for production of appropriate signaling activity in embryos and in the imaginal precursors of adult tissues. The ski gene encodes an apparent acyltransferase, and we provide genetic and biochemical evidence that Hh proteins from ski mutant cells retain carboxyl-terminal cholesterol modification but lack amino-terminal palmitate modification. Our results suggest that ski encodes an enzyme that acts within the secretory pathway to catalyze amino-terminal palmitoylation of Hh, and further demonstrate that this lipid modification is required for the embryonic and larval patterning activities of the Hh signal.

  9. Role of Hedgehog Signaling Pathway in NASH

    PubMed Central

    Verdelho Machado, Mariana; Diehl, Anna Mae

    2016-01-01

    Non-alcoholic fatty liver disease (NAFLD) is the number one cause of chronic liver disease in the Western world. Although only a minority of patients will ultimately develop end-stage liver disease, it is not yet possible to efficiently predict who will progress and, most importantly, effective treatments are still unavailable. Better understanding of the pathophysiology of this disease is necessary to improve the clinical management of NAFLD patients. Epidemiological data indicate that NAFLD prognosis is determined by an individual’s response to lipotoxic injury, rather than either the severity of exposure to lipotoxins, or the intensity of liver injury. The liver responds to injury with a synchronized wound-healing response. When this response is abnormal, it leads to pathological scarring, resulting in progressive fibrosis and cirrhosis, rather than repair. The hedgehog pathway is a crucial player in the wound-healing response. In this review, we summarize the pre-clinical and clinical evidence, which demonstrate the role of hedgehog pathway dysregulation in NAFLD pathogenesis, and the preliminary data that place the hedgehog pathway as a potential target for the treatment of this disease. PMID:27258259

  10. Regulation of Hedgehog Signalling Inside and Outside the Cell

    PubMed Central

    Ramsbottom, Simon A.; Pownall, Mary E.

    2016-01-01

    The hedgehog (Hh) signalling pathway is conserved throughout metazoans and plays an important regulatory role in both embryonic development and adult homeostasis. Many levels of regulation exist that control the release, reception, and interpretation of the hedgehog signal. The fatty nature of the Shh ligand means that it tends to associate tightly with the cell membrane, and yet it is known to act as a morphogen that diffuses to elicit pattern formation. Heparan sulfate proteoglycans (HSPGs) play a major role in the regulation of Hh distribution outside the cell. Inside the cell, the primary cilium provides an important hub for processing the Hh signal in vertebrates. This review will summarise the current understanding of how the Hh pathway is regulated from ligand production, release, and diffusion, through to signal reception and intracellular transduction. PMID:27547735

  11. Hedgehog Signaling Regulates Telomerase Reverse Transcriptase in Human Cancer Cells

    PubMed Central

    Mazumdar, Tapati; Sandhu, Ranjodh; Qadan, Maha; DeVecchio, Jennifer; Magloire, Victoria; Agyeman, Akwasi; Li, Bibo; Houghton, Janet A.

    2013-01-01

    The Hedgehog (HH) signaling pathway is critical for normal embryonic development, tissue patterning and cell differentiation. Aberrant HH signaling is involved in multiple human cancers. HH signaling involves a multi-protein cascade activating the GLI proteins that transcriptionally regulate HH target genes. We have previously reported that HH signaling is essential for human colon cancer cell survival and inhibition of this signal induces DNA damage and extensive cell death. Here we report that the HH/GLI axis regulates human telomerase reverse transcriptase (hTERT), which determines the replication potential of cancer cells. Suppression of GLI1/GLI2 functions by a C-terminus truncated GLI3 repressor mutant (GLI3R), or by GANT61, a pharmacological inhibitor of GLI1/GLI2, reduced hTERT protein expression in human colon cancer, prostate cancer and Glioblastoma multiforme (GBM) cell lines. Expression of an N-terminus deleted constitutively active mutant of GLI2 (GLI2ΔN) increased hTERT mRNA and protein expression and hTERT promoter driven luciferase activity in human colon cancer cells while GANT61 inhibited hTERT mRNA expression and hTERT promoter driven luciferase activity. Chromatin immunoprecipitation with GLI1 or GLI2 antibodies precipitated fragments of the hTERT promoter in human colon cancer cells, which was reduced upon exposure to GANT61. In contrast, expression of GLI1 or GLI2ΔN in non-malignant 293T cells failed to alter the levels of hTERT mRNA and protein, or hTERT promoter driven luciferase activity. Further, expression of GLI2ΔN increased the telomerase enzyme activity, which was reduced by GANT61 administration in human colon cancer, prostate cancer, and GBM cells. These results identify hTERT as a direct target of the HH signaling pathway, and reveal a previously unknown role of the HH/GLI axis in regulating the replication potential of cancer cells. These findings are of significance in understanding the important regulatory mechanisms that

  12. A review of hedgehog signaling in cranial bone development

    PubMed Central

    Pan, Angel; Chang, Le; Nguyen, Alan; James, Aaron W.

    2013-01-01

    During craniofacial development, the Hedgehog (HH) signaling pathway is essential for mesodermal tissue patterning and differentiation. The HH family consists of three protein ligands: Sonic Hedgehog (SHH), Indian Hedgehog (IHH), and Desert Hedgehog (DHH), of which two are expressed in the craniofacial complex (IHH and SHH). Dysregulations in HH signaling are well documented to result in a wide range of craniofacial abnormalities, including holoprosencephaly (HPE), hypotelorism, and cleft lip/palate. Furthermore, mutations in HH effectors, co-receptors, and ciliary proteins result in skeletal and craniofacial deformities. Cranial suture morphogenesis is a delicate developmental process that requires control of cell commitment, proliferation and differentiation. This review focuses on both what is known and what remains unknown regarding HH signaling in cranial suture morphogenesis and intramembranous ossification. As demonstrated from murine studies, expression of both SHH and IHH is critical to the formation and fusion of the cranial sutures and calvarial ossification. SHH expression has been observed in the cranial suture mesenchyme and its precise function is not fully defined, although some postulate SHH to delay cranial suture fusion. IHH expression is mainly found on the osteogenic fronts of the calvarial bones, and functions to induce cell proliferation and differentiation. Unfortunately, neonatal lethality of IHH deficient mice precludes a detailed examination of their postnatal calvarial phenotype. In summary, a number of basic questions are yet to be answered regarding domains of expression, developmental role, and functional overlap of HH morphogens in the calvaria. Nevertheless, SHH and IHH ligands are integral to cranial suture development and regulation of calvarial ossification. When HH signaling goes awry, the resultant suite of morphologic abnormalities highlights the important roles of HH signaling in cranial development. PMID:23565096

  13. Primary cilia integrate hedgehog and Wnt signaling during tooth development.

    PubMed

    Liu, B; Chen, S; Cheng, D; Jing, W; Helms, J A

    2014-05-01

    Many ciliopathies have clinical features that include tooth malformations but how these defects come about is not clear. Here we show that genetic deletion of the motor protein Kif3a in dental mesenchyme results in an arrest in odontogenesis. Incisors are completely missing, and molars are enlarged in Wnt1(Cre+)Kif3a(fl/fl) embryos. Although amelogenesis and dentinogenesis initiate in the molar tooth bud, both processes terminate prematurely. We demonstrate that loss of Kif3a in dental mesenchyme results in loss of Hedgehog signaling and gain of Wnt signaling in this same tissue. The defective dental mesenchyme then aberrantly signals to the dental epithelia, which prompts an up-regulation in the Hedgehog and Wnt responses in the epithelia and leads to multiple attempts at invagination and an expanded enamel organ. Thus, the primary cilium integrates Hedgehog and Wnt signaling between dental epithelia and mesenchyme, and this cilia-dependent integration is required for proper tooth development.

  14. Mechanism and evolution of cytosolic Hedgehog signal transduction

    PubMed Central

    Wilson, Christopher W.; Chuang, Pao-Tien

    2010-01-01

    Hedgehog (Hh) signaling is required for embryonic patterning and postnatal physiology in invertebrates and vertebrates. With the revelation that the primary cilium is crucial for mammalian Hh signaling, the prevailing view that Hh signal transduction mechanisms are conserved across species has been challenged. However, more recent progress on elucidating the function of core Hh pathway cytosolic regulators in Drosophila, zebrafish and mice has confirmed that the essential logic of Hh transduction is similar between species. Here, we review Hh signaling events at the membrane and in the cytosol, and focus on parallel and divergent functions of cytosolic Hh regulators in Drosophila and mammals. PMID:20530542

  15. Hedgehog Signal Transduction: Key Players, Oncogenic Drivers, and Cancer Therapy.

    PubMed

    Pak, Ekaterina; Segal, Rosalind A

    2016-08-22

    The Hedgehog (Hh) signaling pathway governs complex developmental processes, including proliferation and patterning within diverse tissues. These activities rely on a tightly regulated transduction system that converts graded Hh input signals into specific levels of pathway activity. Uncontrolled activation of Hh signaling drives tumor initiation and maintenance. However, recent entry of pathway-specific inhibitors into the clinic reveals mixed patient responses and thus prompts further exploration of pathway activation and inhibition. In this review, we share emerging insights into regulated and oncogenic Hh signaling, supplemented with updates on the development and use of Hh pathway-targeted therapies.

  16. Hedgehog Signaling and Steroidogenesis Annual Review of Physiology

    PubMed Central

    Finco, Isabella; LaPensee, Christopher R.; Krill, Kenneth T.; Hammer, Gary D.

    2016-01-01

    Since its discovery nearly 30 years ago, the Hedgehog (Hh) signaling pathway has been shown to be pivotal in many developmental and pathophysiological processes in several steroidogenic tissues, including the testis, ovary, adrenal cortex, and placenta. New evidence links the evolutionarily conserved Hh pathway to the steroidogenic organs, demonstrating how Hh signaling can influence their development and homeostasis and can act in concert with steroids to mediate physiological functions. In this review, we highlight the role of the components of the Hh signaling pathway in steroidogenesis of endocrine tissues. PMID:25668018

  17. Hedgehog signaling regulates gene expression in planarian glia

    PubMed Central

    Wang, Irving E; Lapan, Sylvain W; Scimone, M Lucila; Clandinin, Thomas R; Reddien, Peter W

    2016-01-01

    Hedgehog signaling is critical for vertebrate central nervous system (CNS) development, but its role in CNS biology in other organisms is poorly characterized. In the planarian Schmidtea mediterranea, hedgehog (hh) is expressed in medial cephalic ganglia neurons, suggesting a possible role in CNS maintenance or regeneration. We performed RNA sequencing of planarian brain tissue following RNAi of hh and patched (ptc), which encodes the Hh receptor. Two misregulated genes, intermediate filament-1 (if-1) and calamari (cali), were expressed in a previously unidentified non-neural CNS cell type. These cells expressed orthologs of astrocyte-associated genes involved in neurotransmitter uptake and metabolism, and extended processes enveloping regions of high synapse concentration. We propose that these cells are planarian glia. Planarian glia were distributed broadly, but only expressed if-1 and cali in the neuropil near hh+ neurons. Planarian glia and their regulation by Hedgehog signaling present a novel tractable system for dissection of glia biology. DOI: http://dx.doi.org/10.7554/eLife.16996.001 PMID:27612382

  18. Sonic Hedgehog Signalling Pathway and Ameloblastoma - A Review.

    PubMed

    Mishra, Pallavi; Panda, Abikshyeet; Bandyopadhyay, Alokenath; Kumar, Harish; Mohiddin, Gouse

    2015-11-01

    Ameloblastoma is a benign but aggressive odontogenic neoplasm arising from odontogenic epithelium. Many theories have been proposed to explain the pathogenesis of ameloblatoma. Numerous signalling pathways have been implicated to be associated in the development and progression of this neoplasm. Studies have found association of various signalling molecules of Sonic Hedgehog Pathway, namely SHH, PTCH1, SMO, Gli 1, Gli 2, Gli 3, with ameloblastoma. Knowledge about this pathway will help us to understand the nature and behaviour of this neoplasm. This will open the door towards new treatment modalities. PMID:26674664

  19. Sonic Hedgehog Signalling Pathway and Ameloblastoma – A Review

    PubMed Central

    Mishra, Pallavi; Bandyopadhyay, Alokenath; Kumar, Harish; Mohiddin, Gouse

    2015-01-01

    Ameloblastoma is a benign but aggressive odontogenic neoplasm arising from odontogenic epithelium. Many theories have been proposed to explain the pathogenesis of ameloblatoma. Numerous signalling pathways have been implicated to be associated in the development and progression of this neoplasm. Studies have found association of various signalling molecules of Sonic Hedgehog Pathway, namely SHH, PTCH1, SMO, Gli 1, Gli 2, Gli 3, with ameloblastoma. Knowledge about this pathway will help us to understand the nature and behaviour of this neoplasm. This will open the door towards new treatment modalities. PMID:26674664

  20. A directed mutagenesis screen in Drosophila melanogaster reveals new mutants that influence hedgehog signaling.

    PubMed Central

    Haines, N; van den Heuvel, M

    2000-01-01

    The Hedgehog signaling pathway has been recognized as essential for patterning processes in development of metazoan animal species. The signaling pathway is, however, not entirely understood. To start to address this problem, we set out to isolate new mutations that influence Hedgehog signaling. We performed a mutagenesis screen for mutations that dominantly suppress Hedgehog overexpression phenotypes in the Drosophila melanogaster wing. We isolated four mutations that influence Hedgehog signaling. These were analyzed in the amenable wing system using genetic and molecular techniques. One of these four mutations affects the stability of the Hedgehog expression domain boundary, also known as the organizer in the developing wing. Another mutation affects a possible Hedgehog autoregulation mechanism, which stabilizes the same boundary. PMID:11102373

  1. Smoothened transduces Hedgehog signal by forming a complex with Evc/Evc2.

    PubMed

    Yang, Cuiping; Chen, Wenlin; Chen, Yongbin; Jiang, Jin

    2012-11-01

    Hedgehog (Hh) signaling plays pivotal roles in embryonic development and adult tissue homeostasis in species ranging from Drosophila to mammals. The Hh signal is transduced by Smoothened (Smo), a seven-transmembrane protein related to G protein coupled receptors. Despite a conserved mechanism by which Hh activates Smo in Drosophila and mammals, how mammalian Hh signal is transduced from Smo to the Gli transcription factors is poorly understood. Here, we provide evidence that two ciliary proteins, Evc and Evc2, the products of human disease genes responsible for the Ellis-van Creveld syndrome, act downstream of Smo to transduce the Hh signal. We found that loss of Evc/Evc2 does not affect Sonic Hedgehog-induced Smo phosphorylation and ciliary localization but impedes Hh pathway activation mediated by constitutively active forms of Smo. Evc/Evc2 are dispensable for the constitutive Gli activity in Sufu(-/-) cells, suggesting that Evc/Evc2 act upstream of Sufu to promote Gli activation. Furthermore, we demonstrated that Hh stimulates binding of Evc/Evc2 to Smo depending on phosphorylation of the Smo C-terminal intracellular tail and that the binding is abolished in Kif3a(-/-) cilium-deficient cells. We propose that Hh activates Smo by inducing its phosphorylation, which recruits Evc/Evc2 to activate Gli proteins by antagonizing Sufu in the primary cilia.

  2. Phosphorylation of the fused protein kinase in response to signaling from hedgehog.

    PubMed Central

    Thérond, P P; Knight, J D; Kornberg, T B; Bishop, J M

    1996-01-01

    The hedgehog gene (hh) of Drosophila melanogaster exerts both short- and long-range effects on cell patterning during development. The product of hedgehog is a secreted protein that apparently acts by triggering an intra-cellular signaling pathway, but little is known about the details of that pathway. The Drosophila gene fused (fu) encodes a serine/threonine-protein kinase that genetic experiments have implicated in signaling initiated by hedgehog. Here we report that the fused protein is phosphorylated during the course of Drosophila embryogenesis, as a result of hedgehog activity. In cell culture, phosphorylation of fused protein occurs in response to the biologically active form of hedgehog and cannot be blocked by activation of protein kinase A, which is thought to be an antagonist of signaling from hedgehog. These results suggest that fused and protein kinase A function downstream of hedgehog but in parallel pathways that eventually converge distal to fused. The reconstruction of signaling from hedgehog in cell culture should provide further access to the mechanisms by which hedgehog acts. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8633045

  3. Dendrosomatic Sonic Hedgehog Signaling in Hippocampal Neurons Regulates Axon Elongation

    PubMed Central

    Petralia, Ronald S.; Ott, Carolyn; Wang, Ya-Xian; Lippincott-Schwartz, Jennifer; Mattson, Mark P.

    2015-01-01

    The presence of Sonic Hedgehog (Shh) and its signaling components in the neurons of the hippocampus raises a question about what role the Shh signaling pathway may play in these neurons. We show here that activation of the Shh signaling pathway stimulates axon elongation in rat hippocampal neurons. This Shh-induced effect depends on the pathway transducer Smoothened (Smo) and the transcription factor Gli1. The axon itself does not respond directly to Shh; instead, the Shh signal transduction originates from the somatodendritic region of the neurons and occurs in neurons with and without detectable primary cilia. Upon Shh stimulation, Smo localization to dendrites increases significantly. Shh pathway activation results in increased levels of profilin1 (Pfn1), an actin-binding protein. Mutations in Pfn1's actin-binding sites or reduction of Pfn1 eliminate the Shh-induced axon elongation. These findings indicate that Shh can regulate axon growth, which may be critical for development of hippocampal neurons. SIGNIFICANCE STATEMENT Although numerous signaling mechanisms have been identified that act directly on axons to regulate their outgrowth, it is not known whether signals transduced in dendrites may also affect axon outgrowth. We describe here a transcellular signaling pathway in embryonic hippocampal neurons in which activation of Sonic Hedgehog (Shh) receptors in dendrites stimulates axon growth. The pathway involves the dendritic-membrane-associated Shh signal transducer Smoothened (Smo) and the transcription factor Gli, which induces the expression of the gene encoding the actin-binding protein profilin 1. Our findings suggest scenarios in which stimulation of Shh in dendrites results in accelerated outgrowth of the axon, which therefore reaches its presumptive postsynaptic target cell more quickly. By this mechanism, Shh may play critical roles in the development of hippocampal neuronal circuits. PMID:26658865

  4. Sonic hedgehog, the penis and erectile dysfunction: a review of sonic hedgehog signaling in the penis.

    PubMed

    Podlasek, C A; Meroz, C L; Korolis, H; Tang, Y; McKenna, K E; McVary, K T

    2005-01-01

    The sinusoid anatomy of the penis is complex and requires complicated interaction between smooth muscle and endothelium in order to maintain homeostasis in the adult. The morphogen, Sonic hedgehog (Shh), is a crucial regulator of these processes, along with its down stream targets patched (Ptc), Hox, bone morphogenetic proteins (BMP's), vascular endothelial growth factor (VEGF) and nitric oxide synthase (NOS). Shh is critical for patterning and establishing tissue identity of the penis during embryonic development, is a crucial regulator of penile postnatal differentiation of the sinusoid morphology of the corpora cavernosa, and plays a fundamental role in maintaining sinusoidal structures pertinent to erectile function in the adult rat. Shh and its targets are active in human penes, and decreased in human diabetic penes in parallel with observations in the rat, thus lending clinical significance to the role of abnormal Shh signaling in erectile dysfunction (ED). Application of exogenous Shh protein to rat corpora cavernosa, induces VEGF and NOS proteins, suggesting a potential mechanism through which decreased Shh protein can cause ED. The studies outlined in this review provide in depth analysis of the Shh pathway and signal transduction, its role in penile development, how Shh signaling is altered in a rat model of ED and neuropathy, how abnormal Shh signaling can cause ED, and the clinical significance of the Shh pathway to human ED. These studies will provide valuable insight, at the molecular level, into understanding the mechanisms that under lie ED and lead to new treatment strategies for diabetic impotence. PMID:16378507

  5. Hedgehog Signaling in the Maintenance of Cancer Stem Cells

    PubMed Central

    Cochrane, Catherine R.; Szczepny, Anette; Watkins, D. Neil; Cain, Jason E.

    2015-01-01

    Cancer stem cells (CSCs) represent a rare population of cells with the capacity to self-renew and give rise to heterogeneous cell lineages within a tumour. Whilst the mechanisms underlying the regulation of CSCs are poorly defined, key developmental signaling pathways required for normal stem and progenitor functions have been strongly implicated. Hedgehog (Hh) signaling is an evolutionarily-conserved pathway essential for self-renewal and cell fate determination. Aberrant Hh signaling is associated with the development and progression of various types of cancer and is implicated in multiple aspects of tumourigenesis, including the maintenance of CSCs. Here, we discuss the mounting evidence suggestive of Hh-driven CSCs in the context of haematological malignancies and solid tumours and the novel strategies that hold the potential to block many aspects of the transformation attributed to the CSC phenotype, including chemotherapeutic resistance, relapse and metastasis. PMID:26270676

  6. Roles for Hedgehog signaling in adult organ homeostasis and repair

    PubMed Central

    Petrova, Ralitsa; Joyner, Alexandra L.

    2014-01-01

    The hedgehog (HH) pathway is well known for its mitogenic and morphogenic functions during development, and HH signaling continues in discrete populations of cells within many adult mammalian tissues. Growing evidence indicates that HH regulates diverse quiescent stem cell populations, but the exact roles that HH signaling plays in adult organ homeostasis and regeneration remain poorly understood. Here, we review recently identified functions of HH in modulating the behavior of tissue-specific adult stem and progenitor cells during homeostasis, regeneration and disease. We conclude that HH signaling is a key factor in the regulation of adult tissue homeostasis and repair, acting via multiple different routes to regulate distinct cellular outcomes, including maintenance of plasticity, in a context-dependent manner. PMID:25183867

  7. YAP regulates neuronal differentiation through Sonic hedgehog signaling pathway

    SciTech Connect

    Lin, Yi-Ting; Ding, Jing-Ya; Li, Ming-Yang; Yeh, Tien-Shun; Wang, Tsu-Wei; Yu, Jenn-Yah

    2012-09-10

    Tight regulation of cell numbers by controlling cell proliferation and apoptosis is important during development. Recently, the Hippo pathway has been shown to regulate tissue growth and organ size in Drosophila. In mammalian cells, it also affects cell proliferation and differentiation in various tissues, including the nervous system. Interplay of several signaling cascades, such as Notch, Wnt, and Sonic Hedgehog (Shh) pathways, control cell proliferation during neuronal differentiation. However, it remains unclear whether the Hippo pathway coordinates with other signaling cascades in regulating neuronal differentiation. Here, we used P19 cells, a mouse embryonic carcinoma cell line, as a model to study roles of YAP, a core component of the Hippo pathway, in neuronal differentiation. P19 cells can be induced to differentiate into neurons by expressing a neural bHLH transcription factor gene Ascl1. Our results showed that YAP promoted cell proliferation and inhibited neuronal differentiation. Expression of Yap activated Shh but not Wnt or Notch signaling activity during neuronal differentiation. Furthermore, expression of Yap increased the expression of Patched homolog 1 (Ptch1), a downstream target of the Shh signaling. Knockdown of Gli2, a transcription factor of the Shh pathway, promoted neuronal differentiation even when Yap was over-expressed. We further demonstrated that over-expression of Yap inhibited neuronal differentiation in primary mouse cortical progenitors and Gli2 knockdown rescued the differentiation defect in Yap over-expressing cells. In conclusion, our study reveals that Shh signaling acts downstream of YAP in regulating neuronal differentiation. -- Highlights: Black-Right-Pointing-Pointer YAP promotes cell proliferation and inhibits neuronal differentiation in P19 cells. Black-Right-Pointing-Pointer YAP promotes Sonic hedgehog signaling activity during neuronal differentiation. Black-Right-Pointing-Pointer Knockdown of Gli2 rescues the Yap

  8. Phosphoinositides Regulate Ciliary Protein Trafficking to Modulate Hedgehog Signaling

    PubMed Central

    Roberson, Elle C.; Garcia, Galo; Abedin, Monika; Schurmans, Stéphane; Inoue, Takanari; Reiter, Jeremy F.

    2015-01-01

    SUMMARY Primary cilia interpret vertebrate Hedgehog (Hh) signals. Why cilia are essential for signaling is unclear. One possibility is that some forms of signaling require a distinct membrane lipid composition, found at cilia. We found that the ciliary membrane contains a particular phosphoinositide, PI(4)P, whereas a different phosphoinositide, PI(4,5)P2, is restricted to the membrane of the ciliary base. This distribution is created by Inpp5e, a ciliary phosphoinositide 5-phosphatase. Without Inpp5e, ciliary PI(4,5)P2 levels are elevated and Hh signaling is disrupted. Inpp5e limits the ciliary levels of inhibitors of Hh signaling, including Gpr161 and the PI(4,5)P2-binding protein Tulp3. Increasing ciliary PI(4,5)P2 levels or conferring the ability to bind PI(4)P on Tulp3 increases the ciliary localization of Tulp3. Lowering Tulp3 in cells lacking Inpp5e reduces ciliary Gpr161 levels and restores Hh signaling. Therefore, Inpp5e regulates ciliary membrane phosphoinositide composition, and Tulp3 reads out ciliary phosphoinositides to control ciliary protein localization, enabling Hh signaling. PMID:26305592

  9. Intraflagellar transport, cilia, and mammalian Hedgehog signaling: analysis in mouse embryonic fibroblasts.

    PubMed

    Ocbina, Polloneal Jymmiel R; Anderson, Kathryn V

    2008-08-01

    Genetic studies in the mouse have shown that Intraflagellar Transport (IFT) is essential for mammalian Hedgehog (Hh) signal transduction. In this study, we take advantage of wild type and IFT mutant mouse embryonic fibroblasts (MEFs) to characterize additional aspects of the relationship between IFT and Hh signaling. Exposure to Sonic hedgehog (Shh) ligand or expression of an activated allele of Smo, SmoA1, activates an Hh reporter in wild-type MEFs, but not in MEFs derived from embryos that lack IFT172 or the Dync2h1 subunit of the retrograde IFT motor. Similarly, decreased activity of either Sufu or PKA, two negative regulators of Hh signal transduction, activates the pathway in wild-type, but not IFT mutant, MEFs. In contrast to wild-type MEFs, Smo is constitutively present in the cilia of Dync2h1 mutant MEFs. This finding suggests that IFT-dependent trafficking of Hh pathway components through the cilium is essential for their function.

  10. Arsenic inhibits hedgehog signaling during P19 cell differentiation

    SciTech Connect

    Liu, Jui Tung; Bain, Lisa J.

    2014-12-15

    Arsenic is a toxicant found in ground water around the world, and human exposure mainly comes from drinking water or from crops grown in areas containing arsenic in soils or water. Epidemiological studies have shown that arsenic exposure during development decreased intellectual function, reduced birth weight, and altered locomotor activity, while in vitro studies have shown that arsenite decreased muscle and neuronal cell differentiation. The sonic hedgehog (Shh) signaling pathway plays an important role during the differentiation of both neurons and skeletal muscle. The purpose of this study was to investigate whether arsenic can disrupt Shh signaling in P19 mouse embryonic stem cells, leading to changes muscle and neuronal cell differentiation. P19 embryonic stem cells were exposed to 0, 0.25, or 0.5 μM of sodium arsenite for up to 9 days during cell differentiation. We found that arsenite exposure significantly reduced transcript levels of genes in the Shh pathway in both a time and dose-dependent manner. This included the Shh ligand, which was decreased 2- to 3-fold, the Gli2 transcription factor, which was decreased 2- to 3-fold, and its downstream target gene Ascl1, which was decreased 5-fold. GLI2 protein levels and transcriptional activity were also reduced. However, arsenic did not alter GLI2 primary cilium accumulation or nuclear translocation. Moreover, additional extracellular SHH rescued the inhibitory effects of arsenic on cellular differentiation due to an increase in GLI binding activity. Taken together, we conclude that arsenic exposure affected Shh signaling, ultimately decreasing the expression of the Gli2 transcription factor. These results suggest a mechanism by which arsenic disrupts cell differentiation. - Highlights: • Arsenic exposure decreases sonic hedgehog pathway-related gene expression. • Arsenic decreases GLI2 protein levels and transcriptional activity in P19 cells. • Arsenic exposure does not alter the levels of SHH

  11. Anorectal Malformations Caused by Defects in Sonic Hedgehog Signaling

    PubMed Central

    Mo, Rong; Kim, Jae Hong; Zhang, Jianrong; Chiang, Chin; Hui, Chi-chung; Kim, Peter C. W.

    2001-01-01

    Anorectal malformations are a common clinical problem affecting the development of the distal hindgut in infants. The spectrum of anorectal malformations ranges from the mildly stenotic anus to imperforate anus with a fistula between the urinary and intestinal tracts to the most severe form, persistent cloaca. The etiology, embryology, and pathogenesis of anorectal malformations are poorly understood and controversial. Sonic hedgehog (Shh) is an endoderm-derived signaling molecule that induces mesodermal gene expression in the chick hindgut. However, the role of Shh signaling in mammalian hindgut development is unknown. Here, we show that mutant mice with various defects in the Shh signaling pathway exhibit a spectrum of distal hindgut defects mimicking human anorectal malformations. Shh null-mutant mice display persistent cloaca. Mutant mice lacking Gli2 or Gli3, two zinc finger transcription factors involved in Shh signaling, respectively, exhibit imperforate anus with recto-urethral fistula and anal stenosis. Furthermore, persistent cloaca is also observed in Gli2−/−;Gli3+/−, Gli2+/−;Gli3−/−, and Gli2−/−;Gli3−/− mice demonstrating a gene dose-dependent effect. Therefore, Shh signaling is essential for normal development of the distal hindgut in mice and mutations affecting Shh signaling produce a spectrum of anorectal malformations that may reveal new insights into their human disease equivalents. PMID:11485934

  12. Hedgehog signaling in myofibroblasts directly promotes prostate tumor cell growth†

    PubMed Central

    Domenech, Maribella; Bjerregaard, Robert; Bushman, Wade; Beebe, David J.

    2012-01-01

    Despite strong evidence for the involvement of the stroma in Hedgehog signaling, little is known about the identity of the stromal cells and the signaling mechanisms that mediate the growth promoting effect of Hh signaling. We developed an in vitro co-culture model using microchannel technology to examine the effect of paracrine Hh signaling on proliferation of prostate cancer cells. We show here that activation of Hh signaling in myofibroblasts is sufficient to accelerate tumor cell growth. This effect was independent of any direct effect of Hh ligand on tumor cells or other cellular components of the tumor stroma. Further, the trophic effect of Hh pathway activation in myofibroblasts does not require collaboration of other elements of the stroma or direct physical interaction with the cancer cells. By isolating the tropic effect of Hh pathway activation in prostate stroma, we have taken the first step toward identifying cell-specific mechanisms that mediate the effect of paracrine Hh signaling on tumor growth. PMID:22234342

  13. The Role of Hedgehog Signaling in Tumor Induced Bone Disease

    PubMed Central

    Cannonier, Shellese A.; Sterling, Julie A.

    2015-01-01

    Despite significant progress in cancer treatments, tumor induced bone disease continues to cause significant morbidities. While tumors show distinct mutations and clinical characteristics, they behave similarly once they establish in bone. Tumors can metastasize to bone from distant sites (breast, prostate, lung), directly invade into bone (head and neck) or originate from the bone (melanoma, chondrosarcoma) where they cause pain, fractures, hypercalcemia, and ultimately, poor prognoses and outcomes. Tumors in bone secrete factors (interleukins and parathyroid hormone-related protein) that induce RANKL expression from osteoblasts, causing an increase in osteoclast mediated bone resorption. While the mechanisms involved varies slightly between tumor types, many tumors display an increase in Hedgehog signaling components that lead to increased tumor growth, therapy failure, and metastasis. The work of multiple laboratories has detailed Hh signaling in several tumor types and revealed that tumor establishment in bone can be controlled by both canonical and non-canonical Hh signaling in a cell type specific manner. This review will explore the role of Hh signaling in the modulation of tumor induced bone disease, and will shed insight into possible therapeutic interventions for blocking Hh signaling in these tumors. PMID:26343726

  14. An essential role for Grk2 in Hedgehog signalling downstream of Smoothened.

    PubMed

    Zhao, Zhonghua; Lee, Raymond Teck Ho; Pusapati, Ganesh V; Iyu, Audrey; Rohatgi, Rajat; Ingham, Philip W

    2016-05-01

    The G-protein-coupled receptor kinase 2 (adrbk2/GRK2) has been implicated in vertebrate Hedgehog (Hh) signalling based on the effects of its transient knock-down in mammalian cells and zebrafish embryos. Here, we show that the response to Hh signalling is effectively abolished in the absence of Grk2 activity. Zebrafish embryos lacking all Grk2 activity are refractory to both Sonic hedgehog (Shh) and oncogenic Smoothened (Smo) activity, but remain responsive to inhibition of cAMP-dependent protein kinase (PKA) activity. Mutation of the kinase domain abrogates the rescuing activity of grk2 mRNA, suggesting that Grk2 acts in a kinase-dependent manner to regulate the response to Hh. Previous studies have suggested that Grk2 potentiates Smo activity by phosphorylating its C-terminal tail (CTT). In the zebrafish embryo, however, phosphomimetic Smo does not display constitutive activity, whereas phospho-null mutants retain activity, implying phosphorylation is neither sufficient nor necessary for Smo function. Since Grk2 rescuing activity requires the integrity of domains essential for its interaction with GPCRs, we speculate that Grk2 may regulate Hh pathway activity by downregulation of a GPCR. PMID:27113758

  15. Sonic Hedgehog Signaling in Basal Cell Nevus Syndrome

    PubMed Central

    Athar, Mohammad; Li, Changzhao; Kim, Arianna L.; Spiegelman, Vladimir S; Bickers, David R.

    2014-01-01

    The hedgehog (Hh) signaling pathway is considered to be a major signal transduction pathway during embryonic development but it usually shuts down after birth. Aberrant Shh activation during adulthood leads to neoplastic growth. Basal cell carcinoma (BCC) of the skin is driven by this pathway. Here, we summarize information related to the pathogenesis of this neoplasm, discuss pathways that crosstalk with Shh signaling and the importance of the primary cilium in this neoplastic process. The identification of the basic/translational components of Shh signaling has led to the discovery of potential mechanism-driven druggable targets and subsequent clinical trials have confirmed their remarkable efficacy in treating BCCs particularly in patients with Nevoid Basal Cell Carcinoma Syndrome (NBCCS), an autosomal dominant disorder in which patients inherit a germline mutation in the tumor suppressor gene Patched (Ptch). Patients with NBCCS develop dozens to hundreds of BCCs due to de-repression of the downstream G-protein coupled receptor Smoothened (SMO). Ptch mutations permit transposition of SMO to the primary cilium followed by enhanced expression of transcription factors Glis that drive cell proliferation and tumor growth. Clinical trials with the SMO inhibitor, vismodegib, in patients with NBCCS showing remarkable efficacy finally led to its FDA approval in 2012. PMID:25172843

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

    PubMed Central

    Sims-Mourtada, Jennifer; Yang, David; Tworowska, Izabela; Larson, Richard; Smith, Daniel; Tsao, Ning; Opdenaker, Lynn; Mourtada, Firas; Woodward, Wendy

    2012-01-01

    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 of 131I-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 of 131I-SHH is significantly decreased following treatment with cyclopamine. In vivo imaging and biodistribution studies revealed significant accumulation of 131I-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 that 131I-SHH is capable of in vivo detection 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. PMID:22811598

  17. SOX18 Is a Novel Target Gene of Hedgehog Signaling in Cervical Carcinoma Cell Lines

    PubMed Central

    Popovic, Jelena; Schwirtlich, Marija; Rankovic, Branislava; Stevanovic, Milena

    2015-01-01

    Although there is much evidence showing functional relationship between Hedgehog pathway, in particular Sonic hedgehog, and SOX transcription factors during embryonic development, scarce data are available regarding their crosstalk in cancer cells. SOX18 protein plays an important role in promoting tumor angiogenesis and therefore emerged as a promising potential target in antiangiogenic tumor therapy. Recently it became evident that expression of SOX18 gene in tumors is not restricted to endothelium of accompanying blood and lymphatic vessels, but in tumor cells as well.In this paper we have identified human SOX18 gene as a novel target gene of Hedgehog signaling in cervical carcinoma cell lines. We have presented data showing that expression of SOX18 gene is regulated by GLI1 and GLI2 transcription factors, final effectors of Hedgehog signaling, and that modulation of Hedgehog signaling activity in considerably influence SOX18 expression. We consider important that Hedgehog pathway inhibitors reduced SOX18 expression, thus showing, for the first time, possibility for manipulationwith SOX18 gene expression. In addition, we analyzed the role of SOX18 in malignant potential of cervical carcinoma cell line, and showed that its overexpression has no influence on cells proliferation and viability, but substantially promotes migration and invasion of cells in vitro. Pro-migratory effect of SOX18 suggests its role in promoting malignant spreading, possibly in response to Hedgehog activation. PMID:26588701

  18. Hedgehog signaling regulates liver sinusoidal endothelial cell capillarisation

    PubMed Central

    Xie, Guanhua; Choi, Steve S.; Syn, Wing-Kin; Michelotti, Gregory A.; Swiderska-Syn, Marzena; Karaca, Gamze; Chan, Isaac S.; Chen, Yuping; Diehl, Anna Mae

    2013-01-01

    Objective Vascular remodeling during liver damage involves loss of healthy liver sinusoidal endothelial cell (LSEC) phenotype via capillarisation. Hedgehog (Hh) signaling regulates vascular development and increases during liver injury. Therefore, we examined its role in capillarisation. Design Primary LSEC were cultured for 5 days to induce capillarisation. Pharmacologic, antibody-mediated, and genetic approaches were used to manipulate Hh signaling. Effects on mRNA and protein expression of Hh-regulated genes and capillarisation markers were evaluated by qRT-PCR and immunoblot. Changes in LSEC function were assessed by migration and tube forming assay, and gain/loss of fenestrae was examined by electron microscopy. Mice with acute or chronic liver injury were treated with Hh inhibitors; effects on capillarisation were assessed by immunohistochemistry. Results Freshly isolated LSEC expressed Hh ligands, Hh receptors, and Hh ligand antagonist Hhip. Capillarisation was accompanied by repression of Hhip and increased expression of Hh-regulated genes. Treatment with Hh agonist further induced expression of Hh ligands and Hh-regulated genes, and up-regulated capillarisation-associated genes; whereas Hh signaling antagonist or Hh ligand neutralizing antibody each repressed expression of Hh target genes and capillarisation markers. LSEC isolated from SmoloxP/loxP transgenic mice that had been infected with adenovirus expressing Cre-recombinase to delete Smoothened showed over 75% knockdown of Smoothened. During culture, Smoothened-deficient LSEC had inhibited Hh signaling, less induction of capillarisation-associated genes, and retention of fenestrae. In mice with injured livers, inhibiting Hh signaling prevented capillarisation. Conclusions LSEC produce and respond to Hh ligands, and use Hh signaling to regulate complex phenotypic changes that occur during capillarisation. PMID:22362915

  19. Canonical and non-canonical Hedgehog signalling and the control of metabolism

    PubMed Central

    Teperino, Raffaele; Aberger, Fritz; Esterbauer, Harald; Riobo, Natalia; Pospisilik, John Andrew

    2014-01-01

    Obesity and diabetes represent key healthcare challenges of our day, affecting upwards of one billion people worldwide. These individuals are at higher risk for cancer, stroke, blindness, heart and cardiovascular disease, and to date, have no effective long-term treatment options available. Recent and accumulating evidence has implicated the developmental morphogen Hedgehog and its downstream signalling in metabolic control. Generally thought to be quiescent in adults, Hedgehog is associated with several human cancers, and as such, has already emerged as a therapeutic target in oncology. Here, we attempt to give a comprehensive overview of the key signalling events associated with both canonical and non-canonical Hedgehog signalling, and highlight the increasingly complex regulatory modalities that appear to link Hedgehog and control metabolism. We highlight these key findings and discuss their impact for therapeutic development, cancer and metabolic disease. PMID:24862854

  20. Pentoxifylline inhibits liver fibrosis via hedgehog signaling pathway.

    PubMed

    Li, Hui; Hua, Juan; Guo, Chun-Xia; Wang, Wei-Xian; Wang, Bao-Ju; Yang, Dong-Liang; Wei, Ping; Lu, Yin-Ping

    2016-06-01

    Infection of schistosomiasis japonica may eventually lead to liver fibrosis, and no effective antifibrotic therapies are available but liver transplantation. Hedgehog (HH) signaling pathway has been involved in the process and is a promising target for treating liver fibrosis. This study aimed to explore the effects of pentoxifylline (PTX) on liver fibrosis induced by schistosoma japonicum infection by inhibiting the HH signaling pathway. Phorbol12-myristate13-acetate (PMA) was used to induce human acute mononuclear leukemia cells THP-1 to differentiate into macrophages. The THP-1-derived macrophages were stimulated by soluble egg antigen (SEA), and the culture supernatants were collected for detection of activation of macrophages. Cell Counting Kit-8 (CCK-8) was used to detect the cytotoxicity of the culture supernatant and PTX on the LX-2 cells. The LX-2 cells were administered with activated culture supernatant from macrophages and(or) PTX to detect the transforming growth factor-β gene expression. The mRNA expression of shh and gli-1, key parts in HH signaling pathway, was detected. The mRNA expression of shh and gli-1 was increased in LX-2 cells treated with activated macrophages-derived culture supernatant, suggesting HH signaling pathway may play a key role in the activation process of hepatic stellate cells (HSCs). The expression of these genes decreased in LX-2 cells co-cultured with both activated macrophages-derived culture supernatant and PTX, indicating PTX could suppress the activation process of HSCs. In conclusion, these data provide evidence that PTX prevents liver fibrogenesis in vitro by the suppression of HH signaling pathway. PMID:27376806

  1. Hedgehog signaling regulates dental papilla formation and tooth size during zebrafish odontogenesis

    PubMed Central

    Yu, Jeffrey C.; Fox, Zachary D.B.; Crimp, James L.; Littleford, Hana E.; Jowdry, Andrea L.; Jackman, William R.

    2015-01-01

    Background Intercellular communication by the hedgehog cell signaling pathway is necessary for tooth development throughout the vertebrates, but it remains unclear which specific developmental signals control cell behavior at different stages of odontogenesis. To address this issue, we have manipulated hedgehog activity during zebrafish tooth development and visualized the results using confocal microscopy. Results We first established that reporter lines for dlx2b, fli1, NF-κB, and prdm1a are markers for specific subsets of tooth germ tissues. We then blocked hedgehog signaling with cyclopamine and observed a reduction or elimination of the cranial neural crest derived dental papilla, which normally contains the cells that later give rise to dentin-producing odontoblasts. Upon further investigation we observed that the dental papilla begins to form and then regresses in the absence of hedgehog signaling, through a mechanism unrelated to cell proliferation or apoptosis. We also found evidence of an isometric reduction in tooth size that correlates with the time of earliest hedgehog inhibition. Conclusions We hypothesize that these results reveal a previously uncharacterized function of hedgehog signaling during tooth morphogenesis, regulating the number of cells in the dental papilla and thereby controlling tooth size. PMID:25645398

  2. Activation of Smurf E3 Ligase Promoted by Smoothened Regulates Hedgehog Signaling through Targeting Patched Turnover

    PubMed Central

    Zheng, Xiudeng; Chen, Zhenping; Sun, Liwei; Wang, Hailong; Zhu, Yuanxiang; Zhang, Jing; Yang, Shuyan; Lu, Yi; Sun, Qinmiao; Tao, Yi; Liu, Feng; Zhao, Yun; Chen, Dahua

    2013-01-01

    Hedgehog signaling plays conserved roles in controlling embryonic development; its dysregulation has been implicated in many human diseases including cancers. Hedgehog signaling has an unusual reception system consisting of two transmembrane proteins, Patched receptor and Smoothened signal transducer. Although activation of Smoothened and its downstream signal transduction have been intensively studied, less is known about how Patched receptor is regulated, and particularly how this regulation contributes to appropriate Hedgehog signal transduction. Here we identified a novel role of Smurf E3 ligase in regulating Hedgehog signaling by controlling Patched ubiquitination and turnover. Moreover, we showed that Smurf-mediated Patched ubiquitination depends on Smo activity in wing discs. Mechanistically, we found that Smo interacts with Smurf and promotes it to mediate Patched ubiquitination by targeting the K1261 site in Ptc. The further mathematic modeling analysis reveals that a bidirectional control of activation of Smo involving Smurf and Patched is important for signal-receiving cells to precisely interpret external signals, thereby maintaining Hedgehog signaling reliability. Finally, our data revealed an evolutionarily conserved role of Smurf proteins in controlling Hh signaling by targeting Ptc during development. PMID:24302888

  3. Hedgehog signaling promotes basal progenitor expansion and the growth and folding of the neocortex.

    PubMed

    Wang, Lei; Hou, Shirui; Han, Young-Goo

    2016-07-01

    The unique mental abilities of humans are rooted in the immensely expanded and folded neocortex, which reflects the expansion of neural progenitors, especially basal progenitors including basal radial glia (bRGs) and intermediate progenitor cells (IPCs). We found that constitutively active Sonic hedgehog (Shh) signaling expanded bRGs and IPCs and induced folding in the otherwise smooth mouse neocortex, whereas the loss of Shh signaling decreased the number of bRGs and IPCs and the size of the neocortex. SHH signaling was strongly active in the human fetal neocortex but Shh signaling was not strongly active in the mouse embryonic neocortex, and blocking SHH signaling in human cerebral organoids decreased the number of bRGs. Mechanistically, Shh signaling increased the initial generation and self-renewal of bRGs and IPC proliferation in mice and the initial generation of bRGs in human cerebral organoids. Thus, robust SHH signaling in the human fetal neocortex may contribute to bRG and IPC expansion and neocortical growth and folding. PMID:27214567

  4. The Insecticide Synergist Piperonyl Butoxide Inhibits Hedgehog Signaling: Assessing Chemical Risks

    PubMed Central

    Chen, Wei

    2012-01-01

    The spread of chemicals, including insecticides, into the environment often raises public health concerns, as exemplified by a recent epidemiologic study associating in utero piperonyl butoxide (PBO) exposure with delayed mental development. The insecticide synergist PBO is listed among the top 10 chemicals detected in indoor dust; a systematic assessment of risks from PBO exposure, as for many toxicants unfortunately, may be underdeveloped when important biological targets that can cause toxicity are unknown. Hedgehog/Smoothened signaling is critical in neurological development. This study was designed to use novel high-throughput in vitro drug screening technology to identify modulators of Hedgehog signaling in environmental chemicals to assist the assessment of their potential risks. A directed library of 1408 environmental toxicants was screened for Hedgehog/Smoothened antagonist activity using a high-content assay that evaluated the interaction between Smoothened and βarrestin2 green fluorescent protein. PBO was identified as a Hedgehog/Smoothened antagonist capable of inhibiting Hedgehog signaling. We found that PBO bound Smoothened and blocked Smoothened overexpression–induced Gli-luciferase reporter activity but had no effect on Gli-1 downstream transcriptional factor–induced Gli activity. PBO inhibited Sonic Hedgehog ligand–induced Gli signaling and mouse cerebellar granular precursor cell proliferation. Moreover, PBO disrupted zebrafish development. Our findings demonstrate the value of high-throughput target-based screening strategies that can successfully evaluate large numbers of environmental toxicants and identify key targets and unknown biological activity that is helpful in properly assessing potential risks. PMID:22552772

  5. Inflammatory PAF Receptor Signaling Initiates Hedgehog Signaling and Kidney Fibrogenesis During Ethanol Consumption.

    PubMed

    Latchoumycandane, Calivarathan; Hanouneh, Mohamad; Nagy, Laura E; McIntyre, Thomas M

    2015-01-01

    Acute inflammation either resolves or proceeds to fibrotic repair that replaces functional tissue. Pro-fibrotic hedgehog signaling and induction of its Gli transcription factor in pericytes induces fibrosis in kidney, but molecular instructions connecting inflammation to fibrosis are opaque. We show acute kidney inflammation resulting from chronic ingestion of the common xenobiotic ethanol initiates Gli1 transcription and hedgehog synthesis in kidney pericytes, and promotes renal fibrosis. Ethanol ingestion stimulated transcription of TGF-ß, collagens I and IV, and alpha-smooth muscle actin with accumulation of these proteins. This was accompanied by deposition of extracellular fibrils. Ethanol catabolism by CYP2E1 in kidney generates local reactive oxygen species that oxidize cellular phospholipids to phospholipid products that activate the Platelet-activating Factor receptor (PTAFR) for inflammatory phospholipids. Genetically deleting this ptafr locus abolished accumulation of mRNA for TGF-ß, collagen IV, and α-smooth muscle actin. Loss of PTAFR also abolished ethanol-stimulated Sonic (Shh) and Indian hedgehog (Ihh) expression, and abolished transcription and accumulation of Gli1. Shh induced in pericytes and Ihh in tubules escaped to urine of ethanol-fed mice. Neutrophil myeloperoxidase (MPO) is required for ethanol-induced kidney inflammation, and Shh was not present in kidney or urine of mpo-/- mice. Shh also was present in urine of patients with acute kidney injury, but not in normal individuals or those with fibrotic liver cirrhosis We conclude neither endogenous PTAFR signaling nor CYP2E1-generated radicals alone are sufficient to initiate hedgehog signaling, but instead PTAFR-dependent neutrophil infiltration with myeloperoxidase activation is necessary to initiate ethanol-induced fibrosis in kidney. We also show fibrogenic mediators escape to urine, defining a new class of urinary mechanistic biomarkers of fibrogenesis for an organ not commonly

  6. Functional Interaction between HEXIM and Hedgehog Signaling during Drosophila Wing Development.

    PubMed

    Nguyen, Duy; Fayol, Olivier; Buisine, Nicolas; Lecorre, Pierrette; Uguen, Patricia

    2016-01-01

    Studying the dynamic of gene regulatory networks is essential in order to understand the specific signals and factors that govern cell proliferation and differentiation during development. This also has direct implication in human health and cancer biology. The general transcriptional elongation regulator P-TEFb regulates the transcriptional status of many developmental genes. Its biological activity is controlled by an inhibitory complex composed of HEXIM and the 7SK snRNA. Here, we examine the function of HEXIM during Drosophila development. Our key finding is that HEXIM affects the Hedgehog signaling pathway. HEXIM knockdown flies display strong phenotypes and organ failures. In the wing imaginal disc, HEXIM knockdown initially induces ectopic expression of Hedgehog (Hh) and its transcriptional effector Cubitus interuptus (Ci). In turn, deregulated Hedgehog signaling provokes apoptosis, which is continuously compensated by apoptosis-induced cell proliferation. Thus, the HEXIM knockdown mutant phenotype does not result from the apoptotic ablation of imaginal disc; but rather from the failure of dividing cells to commit to a proper developmental program due to Hedgehog signaling defects. Furthermore, we show that ci is a genetic suppressor of hexim. Thus, HEXIM ensures the integrity of Hedgehog signaling in wing imaginal disc, by a yet unknown mechanism. To our knowledge, this is the first time that the physiological function of HEXIM has been addressed in such details in vivo. PMID:27176767

  7. Functional Interaction between HEXIM and Hedgehog Signaling during Drosophila Wing Development

    PubMed Central

    Nguyen, Duy; Fayol, Olivier; Buisine, Nicolas; Lecorre, Pierrette; Uguen, Patricia

    2016-01-01

    Studying the dynamic of gene regulatory networks is essential in order to understand the specific signals and factors that govern cell proliferation and differentiation during development. This also has direct implication in human health and cancer biology. The general transcriptional elongation regulator P-TEFb regulates the transcriptional status of many developmental genes. Its biological activity is controlled by an inhibitory complex composed of HEXIM and the 7SK snRNA. Here, we examine the function of HEXIM during Drosophila development. Our key finding is that HEXIM affects the Hedgehog signaling pathway. HEXIM knockdown flies display strong phenotypes and organ failures. In the wing imaginal disc, HEXIM knockdown initially induces ectopic expression of Hedgehog (Hh) and its transcriptional effector Cubitus interuptus (Ci). In turn, deregulated Hedgehog signaling provokes apoptosis, which is continuously compensated by apoptosis-induced cell proliferation. Thus, the HEXIM knockdown mutant phenotype does not result from the apoptotic ablation of imaginal disc; but rather from the failure of dividing cells to commit to a proper developmental program due to Hedgehog signaling defects. Furthermore, we show that ci is a genetic suppressor of hexim. Thus, HEXIM ensures the integrity of Hedgehog signaling in wing imaginal disc, by a yet unknown mechanism. To our knowledge, this is the first time that the physiological function of HEXIM has been addressed in such details in vivo. PMID:27176767

  8. Hedgehog signaling is synergistically enhanced by nutritional deprivation and ligand stimulation in human fibroblasts of Gorlin syndrome.

    PubMed

    Mizuochi, Hiromi; Fujii, Katsunori; Shiohama, Tadashi; Uchikawa, Hideki; Shimojo, Naoki

    2015-02-13

    Hedgehog signaling is a pivotal developmental pathway that comprises hedgehog, PTCH1, SMO, and GLI proteins. Mutations in PTCH1 are responsible for Gorlin syndrome, which is characterized by developmental defects and tumorigenicity. Although the hedgehog pathway has been investigated extensively in Drosophila and mice, its functional roles have not yet been determined in human cells. In order to elucidate the mechanism by which transduction of the hedgehog signal is regulated in human tissues, we employed human fibroblasts derived from three Gorlin syndrome patients and normal controls. We investigated GLI1 transcription, downstream of hedgehog signaling, to assess native signal transduction, and then treated fibroblasts with a recombinant human hedgehog protein with or without serum deprivation. We also examined the transcriptional levels of hedgehog-related genes under these conditions. The expression of GLI1 mRNA was significantly higher in Gorlin syndrome-derived fibroblasts than in control cells. Hedgehog stimulation and nutritional deprivation synergistically enhanced GLI1 transcription levels, and this was blocked more efficiently by vismodegib, a SMO inhibitor, than by the natural compound, cyclopamine. Messenger RNA profiling revealed the increased expression of Wnt signaling and morphogenetic molecules in these fibroblasts. These results indicated that the hedgehog stimulation and nutritional deprivation synergistically activated the hedgehog signaling pathway in Gorlin syndrome fibroblasts, and this was associated with increments in the transcription levels of hedgehog-related genes such as those involved in Wnt signaling. These fibroblasts may become a significant tool for predicting the efficacies of hedgehog molecular-targeted therapies such as vismodegib. PMID:25576868

  9. Distinct roles of PTCH2 splice variants in Hedgehog signalling.

    PubMed Central

    Rahnama, Fahimeh; Toftgård, Rune; Zaphiropoulos, Peter G

    2004-01-01

    The human PTCH2 gene is highly similar to PTCH1, a tumour suppressor gene frequently mutated in basal cell carcinoma and several other tumour types. PTCH1 is a transmembrane protein believed to inhibit another transmembrane protein SMO (Smoothened), which mediates HH (Hedgehog) signalling. In this study, we analysed the biological properties of several PTCH2 splice variants. An mRNA form that lacked the last exon was abundantly expressed in all tissues examined, in contrast with the one that included it. Moreover, a transcript lacking exon 9, which is a part of a conserved sterol-sensing domain, was identified in intestine, prostate and cerebellum. In ovary, spleen, testis, cerebellum and skin, an mRNA lacking both exons 9 and 10 could also be observed. The different PTCH2 isoforms localized in the cytoplasm were capable of internalizing the N-terminal fragment of Sonic HH (Shh-N). Additionally, the PTCH2 gene was found to be a target of HH signalling. PTCH2 promoter regulation assays demonstrated that only one of the PTCH2 variants could inhibit the activity of SHH-N, whereas none was capable of inhibiting the activated form of SMO (SMO-M2) and this contrasts with PTCH1. Despite the fact that the PTCH2 isoforms lacked the ability to inhibit SMO-M2 activity, all PTCH2 variants as well as PTCH1, on co-transfection with Smo, were able to change Smo localization from being largely dispersed in the cytoplasm to the juxtanuclear region. Furthermore, the PTCH2 isoforms and PTCH1 co-localized in doubly transfected cells and an interaction between them was confirmed using immunoprecipitation assays. Using Ptch1-/- mouse cells, it was shown that the PTCH2 variants and PTCH1 differentially act to reconstitute not only the SHH but also the Desert HH-dependent transcriptional response. We conclude that in spite of their structural similarities, the PTCH2 isoforms have distinct functional properties when compared with PTCH1. PMID:14613484

  10. Hedgehog Signaling Components Are Expressed in Choroidal Neovascularization in Laser-induced Retinal Lesion.

    PubMed

    Nochioka, Katsunori; Okuda, Hiroaki; Tatsumi, Kouko; Morita, Shoko; Ogata, Nahoko; Wanaka, Akio

    2016-04-28

    Choroidal neovascularization is one of the major pathological changes in age-related macular degeneration, which causes devastating blindness in the elderly population. The molecular mechanism of choroidal neovascularization has been under extensive investigation, but is still an open question. We focused on sonic hedgehog signaling, which is implicated in angiogenesis in various organs. Laser-induced injuries to the mouse retina were made to cause choroidal neovascularization. We examined gene expression of sonic hedgehog, its receptors (patched1, smoothened, cell adhesion molecule down-regulated by oncogenes (Cdon) and biregional Cdon-binding protein (Boc)) and downstream transcription factors (Gli1-3) using real-time RT-PCR. At seven days after injury, mRNAs for Patched1 and Gli1 were upregulated in response to injury, but displayed no upregulation in control retinas. Immunohistochemistry revealed that Patched1 and Gli1 proteins were localized to CD31-positive endothelial cells that cluster between the wounded retina and the pigment epithelium layer. Treatment with the hedgehog signaling inhibitor cyclopamine did not significantly decrease the size of the neovascularization areas, but the hedgehog agonist purmorphamine made the areas significantly larger than those in untreated retina. These results suggest that the hedgehog-signaling cascade may be a therapeutic target for age-related macular degeneration. PMID:27239075

  11. Hedgehog Signaling Components Are Expressed in Choroidal Neovascularization in Laser-induced Retinal Lesion

    PubMed Central

    Nochioka, Katsunori; Okuda, Hiroaki; Tatsumi, Kouko; Morita, Shoko; Ogata, Nahoko; Wanaka, Akio

    2016-01-01

    Choroidal neovascularization is one of the major pathological changes in age-related macular degeneration, which causes devastating blindness in the elderly population. The molecular mechanism of choroidal neovascularization has been under extensive investigation, but is still an open question. We focused on sonic hedgehog signaling, which is implicated in angiogenesis in various organs. Laser-induced injuries to the mouse retina were made to cause choroidal neovascularization. We examined gene expression of sonic hedgehog, its receptors (patched1, smoothened, cell adhesion molecule down-regulated by oncogenes (Cdon) and biregional Cdon-binding protein (Boc)) and downstream transcription factors (Gli1-3) using real-time RT-PCR. At seven days after injury, mRNAs for Patched1 and Gli1 were upregulated in response to injury, but displayed no upregulation in control retinas. Immunohistochemistry revealed that Patched1 and Gli1 proteins were localized to CD31-positive endothelial cells that cluster between the wounded retina and the pigment epithelium layer. Treatment with the hedgehog signaling inhibitor cyclopamine did not significantly decrease the size of the neovascularization areas, but the hedgehog agonist purmorphamine made the areas significantly larger than those in untreated retina. These results suggest that the hedgehog-signaling cascade may be a therapeutic target for age-related macular degeneration. PMID:27239075

  12. Cell context-specific expression of primary cilia in the human testis and ciliary coordination of Hedgehog signalling in mouse Leydig cells.

    PubMed

    Nygaard, Marie Berg; Almstrup, Kristian; Lindbæk, Louise; Christensen, Søren Tvorup; Svingen, Terje

    2015-01-01

    Primary cilia are sensory organelles that coordinate numerous cellular signalling pathways during development and adulthood. Defects in ciliary assembly or function lead to a series of developmental disorders and diseases commonly referred to as ciliopathies. Still, little is known about the formation and function of primary cilia in the mammalian testis. Here, we characterized primary cilia in adult human testis and report a constitutive expression of cilia in peritubular myoid cells and a dynamic expression of cilia in differentiating Leydig cells. Primary cilia are generally absent from cells of mature seminiferous epithelium, but present in Sertoli cell-only tubules in Klinefelter syndrome testis. Peritubular cells in atrophic testis produce overly long cilia. Furthermore cultures of growth-arrested immature mouse Leydig cells express primary cilia that are enriched in components of Hedgehog signalling, including Smoothened, Patched-1, and GLI2, which are involved in regulating Leydig cell differentiation. Stimulation of Hedgehog signalling increases the localization of Smoothened to the cilium, which is followed by transactivation of the Hedgehog target genes, Gli1 and Ptch1. Our findings provide new information on the spatiotemporal formation of primary cilia in the testis and show that primary cilia in immature Leydig cells mediate Hedgehog signalling. PMID:25992706

  13. Cell context-specific expression of primary cilia in the human testis and ciliary coordination of Hedgehog signalling in mouse Leydig cells.

    PubMed

    Nygaard, Marie Berg; Almstrup, Kristian; Lindbæk, Louise; Christensen, Søren Tvorup; Svingen, Terje

    2015-01-01

    Primary cilia are sensory organelles that coordinate numerous cellular signalling pathways during development and adulthood. Defects in ciliary assembly or function lead to a series of developmental disorders and diseases commonly referred to as ciliopathies. Still, little is known about the formation and function of primary cilia in the mammalian testis. Here, we characterized primary cilia in adult human testis and report a constitutive expression of cilia in peritubular myoid cells and a dynamic expression of cilia in differentiating Leydig cells. Primary cilia are generally absent from cells of mature seminiferous epithelium, but present in Sertoli cell-only tubules in Klinefelter syndrome testis. Peritubular cells in atrophic testis produce overly long cilia. Furthermore cultures of growth-arrested immature mouse Leydig cells express primary cilia that are enriched in components of Hedgehog signalling, including Smoothened, Patched-1, and GLI2, which are involved in regulating Leydig cell differentiation. Stimulation of Hedgehog signalling increases the localization of Smoothened to the cilium, which is followed by transactivation of the Hedgehog target genes, Gli1 and Ptch1. Our findings provide new information on the spatiotemporal formation of primary cilia in the testis and show that primary cilia in immature Leydig cells mediate Hedgehog signalling.

  14. Activation of Hedgehog signaling by the environmental toxicant arsenic may contribute to the etiology of arsenic-induced tumors.

    PubMed

    Fei, Dennis Liang; Li, Hua; Kozul, Courtney D; Black, Kendall E; Singh, Samer; Gosse, Julie A; DiRenzo, James; Martin, Kathleen A; Wang, Baolin; Hamilton, Joshua W; Karagas, Margaret R; Robbins, David J

    2010-03-01

    Exposure to the environmental toxicant arsenic, through both contaminated water and food, contributes to significant health problems worldwide. In particular, arsenic exposure is thought to function as a carcinogen for lung, skin, and bladder cancer via mechanisms that remain largely unknown. More recently, the Hedgehog signaling pathway has also been implicated in the progression and maintenance of these same cancers. Based on these similarities, we tested the hypothesis that arsenic may act in part through activating Hedgehog signaling. Here, we show that arsenic is able to activate Hedgehog signaling in several primary and established tissue culture cells as well as in vivo. Arsenic activates Hedgehog signaling by decreasing the stability of the repressor form of GLI3, one of the transcription factors that ultimately regulate Hedgehog activity. We also show, using tumor samples from a cohort of bladder cancer patients, that high levels of arsenic exposure are associated with high levels of Hedgehog activity. Given the important role Hedgehog signaling plays in the maintenance and progression of a variety of tumors, including bladder cancer, these results suggest that arsenic exposure may in part promote cancer through the activation of Hedgehog signaling. Thus, we provide an important insight into the etiology of arsenic-induced human carcinogenesis, which may be relevant to millions of people exposed to high levels of arsenic worldwide.

  15. Seminiferous cord formation is regulated by hedgehog signaling in the marsupial.

    PubMed

    Chung, Jin Wei; Pask, Andrew J; Renfree, Marilyn B

    2012-03-01

    The signaling molecule DHH, secreted by Sertoli cells, has essential regulatory functions in testicular differentiation. DHH is required for the differentiation of peritubular myoid cells that line the seminiferous cords and steroidogenic Leydig cells. The testicular cords in Dhh-null male mice lack a basal lamina and develop abnormally. To date, the DHH-signaling pathway has never been examined outside of any eutherian mammals. This study examined the effects of inhibition of DHH signaling in a marsupial mammal, the tammar wallaby, by culturing gonads in vitro in the presence of the hedgehog-signaling inhibitors cyclopamine and forskolin. Disruption of hedgehog signaling in the tammar testes caused highly disorganized cord formation. SOX9 protein remained strongly expressed in Sertoli cells, laminin distribution was highly fragmented, and germ cells were distributed around the cortical regions of treated testes in an ovarianlike morphology. This suggests that hedgehog signaling regulates cord formation in the tammar wallaby testis as it does in eutherian mammals. These data demonstrate that the hedgehog pathway has been highly conserved in mammals for at least 160 million years. PMID:22133695

  16. Prognostic value of hedgehog signaling pathway in patients with colon cancer.

    PubMed

    Xu, Meihua; Li, Xinhua; Liu, Ting; Leng, Aimin; Zhang, Guiying

    2012-06-01

    Hedgehog signaling pathway plays an important role in normal mammalian gastrointestinal development and is implicated in the oncogenesis of various tumors. However, its correlation with progression and prognosis of colon cancer has not been well documented. This study was designed to investigate expression patterns of related proteins in hedgehog signaling pathway in colon cancer to elucidate its prognostic value in this tumor. Using human colon cancer and their corresponding non-diseased colon from 228 patients' biopsies, the expression of sonic hedgehog, its receptor Patched, and downstream transcription factor Gli1 was investigated by immunohistochemical staining to assess their association with the clinicopathological characteristics of colon cancer. Disease-free survival and overall survival were examined by Kaplan-Meier estimates and the log-rank test. Prognostic factors were determined by multivariate Cox analysis. One hundred and thirty-eight patients (59.6%) had sonic hedgehog-positive tumors and that the disease-free survival (43.5 vs. 73.3%, P < 0.001), and overall survival rates (50.7 vs. 88.9%, P < 0.001) of patients with sonic hedgehog-positive tumors were much lower than those of patients with sonic hedgehog-negative tumors. In addition, 163 patients (71.5%) had Patched-positive tumors, and the disease-free survival (41.7 vs. 76.9%, P < 0.001) and overall survival rates (55.2 vs. 80.0%, P = 0.002) of patients with Patched-positive tumors were also lower than those of patients with Patched-negative tumors. Moreover, positive Gli1 expression had a bad effect on the disease-free survival (41.9 vs. 73.2%, P < 0.001) and overall survival rate of patients with colon cancer (50.0 vs. 89.3%, P < 0.001). In a multivariate analysis, sonic hedgehog, Patched, and Gli1 status were indicators for poor disease-free survival and overall survival. These results have shown that the increasing expression of sonic hedgehog, Patched, and Gli1 are indicators for a poor

  17. Intraflagellar Transport/Hedgehog-Related Signaling Components Couple Sensory Cilium Morphology and Serotonin Biosynthesis in Caenorhabditis elegans

    PubMed Central

    Moussaif, Mustapha; Sze, Ji Ying

    2009-01-01

    Intraflagellar transport in cilia has been proposed as a crucial mediator of Hedgehog signal transduction during embryonic pattern formation in both vertebrates and invertebrates. Here, we show that the Hh receptor Patched-related factor DAF-6 and intraflagellar transport modulate serotonin production in Caenorhabditis elegans animals, by remodeling the architecture of dendritic cilia of a pair of ADF serotonergic chemosensory neurons. Wild-type animals under aversive environment drastically reduce DAF-6 expression in glia-like cells surrounding the cilia of chemosensory neurons, resulting in cilium structural remodeling and upregulation of the serotonin-biosynthesis enzyme tryptophan hydroxylase tph-1 in the ADF neurons. These cellular and molecular modifications are reversed when the environment improves. Mutants of daf-6 or intraflagellar transport constitutively upregulate tph-1 expression. Epistasis analyses indicate that DAF-6/intraflagellar transport and the OCR-2/OSM-9 TRPV channel act in concert, regulating two layers of activation of tph-1 in the ADF neurons. The TRPV signaling turns on tph-1 expression under favorable and aversive conditions, whereas inactivation of DAF-6 by stress results in further upregulation of tph-1 independently of OCR-2/OSM-9 activity. Behavioral analyses suggest that serotonin facilitates larval animals resuming development when the environment improves. Our study revealed the cilium structure of serotonergic neurons as a trigger of regulated serotonin production, and demonstrated that a Hedgehog-related signaling component is dynamically regulated by environment and underscores neuroplasticity of serotonergic neurons in C. elegans under stress and stress recovery. PMID:19339602

  18. Vitamin D3 Inhibits Hedgehog Signaling and Proliferation in Murine Basal Cell Carcinomas

    PubMed Central

    Tang, Jean Y.; Xiao, Tony Zheng; Oda, Yuko; Chang, Kris S.; Shpall, Elana; Wu, Angela; So, Po-Lin; Hebert, Jennifer; Bikle, Daniel; Epstein, Ervin H.

    2011-01-01

    Constitutive Hedgehog (HH) signaling underlies several human tumors, including basal cell carcinoma (BCC). Recently, Bijlsma et al (Bijlsma MF, et al. (2006) PLoS Biol 4: 1397–1410) reported a new biologic function for vitamin D3 in suppressing HH signaling in an in vitro model system. Based on that work, we have assessed effects of vitamin D3 on HH signaling and proliferation of murine BCCs in vitro and in vivo. We find that indeed in BCC cells, vitamin D3 blocks both proliferation and HH signaling as assessed by mRNA expression of the HH target gene Gli1. These effects of vitamin D3 on Gli1 expression and on BCC cell proliferation are comparable to the effects of cyclopamine, a known inhibitor of the HH pathway. These results are specific for vitamin D3, since the precursor 7-dehydrocholesterol and the downstream products 25-hydroxy vitamin D3 [25(OH)D] and 1,25-dihydroxy vitamin D3 [1,25(OH)2D] are considerably less effective in reducing either Gli1 mRNA or cellular proliferation. Moreover, these effects seem to be independent of the vitamin D receptor (VDR) since shRNA knock down of VDR does not abrogate the anti HH effects of D3 despite reducing expression of the VDR target gene 24-hydroxylase. Finally, topical vitamin D3 treatment of existing murine BCC tumors significantly decreases Gli1 and Ki67 staining. Thus, topical vitamin D3 acting via its HH inhibiting effect may hold promise as an effective anti-BCC agent. PMID:21436386

  19. GATA4 and GATA6 regulate pancreatic endoderm identity through inhibition of hedgehog signaling.

    PubMed

    Xuan, Shouhong; Sussel, Lori

    2016-03-01

    GATA4 and GATA6 are zinc finger transcription factors that have important functions in several mesodermal and endodermal organs, including heart, liver and pancreas. In humans, heterozygous mutations of either factor are associated with pancreatic agenesis; however, homozygous deletion of both Gata4 and Gata6 is necessary to disrupt pancreas development in mice. In this study, we demonstrate that arrested pancreatic development in Gata4(fl/fl); Gata6(fl/fl); Pdx1:Cre (pDKO) embryos is accompanied by the transition of ventral and dorsal pancreatic fates into intestinal or stomach lineages, respectively. These results indicate that GATA4 and GATA6 play essential roles in maintaining pancreas identity by regulating foregut endodermal fates. Remarkably, pancreatic anlagen derived from pDKO embryos also display a dramatic upregulation of hedgehog pathway components, which are normally absent from the presumptive pancreatic endoderm. Consistent with the erroneous activation of hedgehog signaling, we demonstrate that GATA4 and GATA6 are able to repress transcription through the sonic hedgehog (Shh) endoderm-specific enhancer MACS1 and that GATA-binding sites within this enhancer are necessary for this repressive activity. These studies establish the importance of GATA4/6-mediated inhibition of hedgehog signaling as a major mechanism regulating pancreatic endoderm specification during patterning of the gut tube.

  20. GATA4 and GATA6 regulate pancreatic endoderm identity through inhibition of hedgehog signaling.

    PubMed

    Xuan, Shouhong; Sussel, Lori

    2016-03-01

    GATA4 and GATA6 are zinc finger transcription factors that have important functions in several mesodermal and endodermal organs, including heart, liver and pancreas. In humans, heterozygous mutations of either factor are associated with pancreatic agenesis; however, homozygous deletion of both Gata4 and Gata6 is necessary to disrupt pancreas development in mice. In this study, we demonstrate that arrested pancreatic development in Gata4(fl/fl); Gata6(fl/fl); Pdx1:Cre (pDKO) embryos is accompanied by the transition of ventral and dorsal pancreatic fates into intestinal or stomach lineages, respectively. These results indicate that GATA4 and GATA6 play essential roles in maintaining pancreas identity by regulating foregut endodermal fates. Remarkably, pancreatic anlagen derived from pDKO embryos also display a dramatic upregulation of hedgehog pathway components, which are normally absent from the presumptive pancreatic endoderm. Consistent with the erroneous activation of hedgehog signaling, we demonstrate that GATA4 and GATA6 are able to repress transcription through the sonic hedgehog (Shh) endoderm-specific enhancer MACS1 and that GATA-binding sites within this enhancer are necessary for this repressive activity. These studies establish the importance of GATA4/6-mediated inhibition of hedgehog signaling as a major mechanism regulating pancreatic endoderm specification during patterning of the gut tube. PMID:26932670

  1. ZnRF3 Induces Apoptosis of Gastric Cancer Cells by Antagonizing Wnt and Hedgehog Signaling.

    PubMed

    Qin, Hongzhen; Cai, Aizhen; Xi, Hongqing; Yuan, Jing; Chen, Lin

    2015-11-01

    A large proportion of malignant cancers of the stomach are gastric adenocarcinoma type. In spite of many studies, the molecular basis for this cancer is still unclear. Deregulated cell proliferative signaling via Wnt/β-catenin and Hedgehog pathways is considered important in the pathogenesis of many cancers including the gastric cancer. Recent studies identified ZnRF3 protein, which is a E3-ubiquitin ligase and which is either deleted or mutated in cancers, to inhibit Wnt signaling. However, the significance of ZnRF3 in the control of gastric cancer and whether it also regulates Hedgehog signaling pathway, is not known. In the present study, we assessed the expression of ZnRF3 in gastric tumors and paracancerous tissues from 58 patients (44 male and 14 female) of different ages and related this to patient survival. We observed a clear relationship between ZnRF3 expression in paracancerous tissue and tumor size. Also, ZnRF3 expression was much higher in tumors from aged patients. Male patients showed higher mortality than the females. Mechanistic studies using normal gastric cells (GES1) and gastric cancer cells (MGC-803) infected with either AdZnRF3 or AdGFP viral vectors, revealed that ZnRF3 overexpression causes significantly more apoptosis and lowered proliferation of cancer cells. ZnRF3 overexpression led to greatly reduced levels of Lgr5, a component of Wnt signaling and also Gli1, a component of Hedgehog signaling. Thus, ZnRF3 negatively influences both the Wnt and Hedgehog proliferative pathways, and probably this way it negatively regulates cancer progression. These results suggest the importance of normal ZnRF3 function in checking the progression of cancer cell growth and indicate that a lack of this protein can lead to poorer clinical outcomes for gastric cancer patients. PMID:27352324

  2. Sonic Hedgehog Signaling Protects Human Hepatocellular Carcinoma Cells Against Ionizing Radiation in an Autocrine Manner

    SciTech Connect

    Chen, Yu-Jen; Lin, Chin-Ping; Hsu, Ming-Ling; Shieh, Hui-Ru; Chao, Nicholas K.; Chao, K.S. Clifford

    2011-07-01

    Purpose: Sonic hedgehog (Shh) signaling is critical to embryogenesis and resistance to chemotherapy. We aimed to examine the role of Shh signaling in the response to radiation of human hepatocellular carcinoma (HCC) cells. Methods and Materials: Response to ionizing radiation therapy (RT) was evaluated by clonogenic assay. Quantitative RT-polymerase chain reaction for patched-1 (PTCH-1) expression was performed. Cytosolic accumulation of Shh and nuclear translocation of Gli-1 were assessed by immunofluorescence. Gli-1 knockdown was done by RNA interference (RNAi). Immunoprecipitation was performed to detect Shh ligand in conditioned medium. Immunofluorescent stain for {gamma}-H2AX was used as an index of DNA double strand breaks (DSB). Expression of proteins related to DNA damage repair was assessed by Western blotting. Results: We found that Shh ligand could protect human HCC HA22T and Sk-Hep1 cells against RT. In HA22T cells, Shh ligand activated the Shh signaling with upregulation of Shh, PTCH-1, and Gli-1 expression. The nuclear translocation of Gli-1 further supports the activation of Gli-1. The radioprotection by Shh ligand was partly blocked by Shh antibody neutralization and was abolished by Gli-1 RNAi, suggesting a critical role of Shh signaling in radiation resistance. Furthermore, we noted that soluble factors secreted into conditioned medium, either constitutively or responding to radiation, by HA22T or Sk-Hep1 cells protected subsequent culturing cells against RT. Immunoprecipitation shows the presence of Shh peptide in conditioned medium. Intriguingly, antibody neutralization of Shh ligand or knockdown of Gli-1 reversed the radioprotective effect of conditioned medium. Furthermore, Shh ligand reduced the RT-induced phosphorylation of checkpoint kinase 1 and impaired the repair of DNA DSB. Conclusions: Activation of Shh signaling protects HCC cells against ionizing radiation in an autocrine manner. Impairment of DNA damage repair might involve

  3. Centrosomal Protein DZIP1 Regulates Hedgehog Signaling by Promoting Cytoplasmic Retention of Transcription Factor GLI3 and Affecting Ciliogenesis*

    PubMed Central

    Wang, Chengbing; Low, Wee-Chuang; Liu, Aimin; Wang, Baolin

    2013-01-01

    The primary cilium is required for Hedgehog signaling. So far, all known ciliogenic proteins regulate Hedgehog signaling through their role in ciliogenesis. Here we show that the mouse DZIP1 regulates Hedgehog signaling through two mechanisms. First, DZIP1 interacts with GLI3, a transcriptional regulator for Hedgehog signaling, and prevents GLI3 from entering the nucleus. Second, DZIP1 is required for ciliogenesis. We show that DZIP1 colocalizes and interacts with CEP164, a protein localizing at appendages of the mother centrioles, and IFT88, a component of the intraflagellar transport (IFT) machinery. Functionally, both CEP164 and Ninein appendage proteins fail to localize to ciliary appendages in Dzip1 mutant cells; IFT components are not recruited to the basal body of cilia. Importantly, the accumulation of GLI3 in the nucleus is independent of loss of primary cilia in Dzip1 mutant cells. Therefore, DZIP1 is the first known ciliogenic protein that regulates Hedgehog signaling through a dual mechanism and that biochemically links IFT machinery with Hedgehog pathway components. PMID:23955340

  4. Structural basis of SUFU–GLI interaction in human Hedgehog signalling regulation

    PubMed Central

    Cherry, Amy L.; Finta, Csaba; Karlström, Mikael; Jin, Qianren; Schwend, Thomas; Astorga-Wells, Juan; Zubarev, Roman A.; Del Campo, Mark; Criswell, Angela R.; de Sanctis, Daniele; Jovine, Luca; Toftgård, Rune

    2013-01-01

    Hedgehog signalling plays a fundamental role in the control of metazoan development, cell proliferation and differentiation, as highlighted by the fact that its deregulation is associated with the development of many human tumours. SUFU is an essential intracellular negative regulator of mammalian Hedgehog signalling and acts by binding and modulating the activity of GLI transcription factors. Despite its central importance, little is known about SUFU regulation and the nature of SUFU–GLI interaction. Here, the crystal and small-angle X-ray scattering structures of full-length human SUFU and its complex with the key SYGHL motif conserved in all GLIs are reported. It is demonstrated that GLI binding is associated with major conformational changes in SUFU, including an intrinsically disordered loop that is also crucial for pathway activation. These findings reveal the structure of the SUFU–GLI interface and suggest a mechanism for an essential regulatory step in Hedgehog signalling, offering possibilities for the development of novel pathway modulators and therapeutics. PMID:24311597

  5. Derivation of lung mesenchymal lineages from the fetal mesothelium requires hedgehog signaling for mesothelial cell entry

    PubMed Central

    Dixit, Radhika; Ai, Xingbin; Fine, Alan

    2013-01-01

    Recent studies have shown that mesothelial progenitors contribute to mesenchymal lineages of developing organs. To what extent the overlying mesothelium contributes to lung development remains unknown. To rigorously address this question, we employed Wt1CreERT2/+ mice for high-fidelity lineage tracing after confirming that Cre recombinase was mesothelial specific and faithfully recapitulated endogenous Wilms’ tumor 1 (Wt1) gene expression. We visualized WT1+ mesothelial cell entry into the lung by live imaging and identified their progenies in subpopulations of bronchial smooth muscle cells, vascular smooth muscle cells and desmin+ fibroblasts by lineage tagging. Derivation of these lineages was only observed with Cre recombinase activation during early lung development. Using loss-of-function assays in organ cultures, and targeted mesothelial-restricted hedgehog loss-of-function mice, we demonstrated that mesothelial cell movement into the lung requires the direct action of hedgehog signaling. By contrast, hedgehog signaling was not required for fetal mesothelial heart entry. These findings further support a paradigm wherein the mesothelium is a source of progenitors for mesenchymal lineages during organogenesis and indicate that signals controlling mesothelial cell entry are organ specific. PMID:24130328

  6. Structural basis of SUFU–GLI interaction in human Hedgehog signalling regulation

    SciTech Connect

    Cherry, Amy L.; Finta, Csaba; Karlström, Mikael; Jin, Qianren; Schwend, Thomas; Astorga-Wells, Juan; Zubarev, Roman A.; Del Campo, Mark; Criswell, Angela R.; Sanctis, Daniele de; Jovine, Luca Toftgård, Rune

    2013-12-01

    Crystal and small-angle X-ray scattering structures of full-length human SUFU alone and in complex with the conserved SYGHL motif from GLI transcription factors show major conformational changes associated with binding and reveal an intrinsically disordered region crucial for pathway activation. Hedgehog signalling plays a fundamental role in the control of metazoan development, cell proliferation and differentiation, as highlighted by the fact that its deregulation is associated with the development of many human tumours. SUFU is an essential intracellular negative regulator of mammalian Hedgehog signalling and acts by binding and modulating the activity of GLI transcription factors. Despite its central importance, little is known about SUFU regulation and the nature of SUFU–GLI interaction. Here, the crystal and small-angle X-ray scattering structures of full-length human SUFU and its complex with the key SYGHL motif conserved in all GLIs are reported. It is demonstrated that GLI binding is associated with major conformational changes in SUFU, including an intrinsically disordered loop that is also crucial for pathway activation. These findings reveal the structure of the SUFU–GLI interface and suggest a mechanism for an essential regulatory step in Hedgehog signalling, offering possibilities for the development of novel pathway modulators and therapeutics.

  7. Activities of the Cytoplasmic Domains of Patched-1 Modulate but Are Not Essential for the Regulation of Canonical Hedgehog Signaling.

    PubMed

    Fleet, Andrew; Lee, Jennifer P Y; Tamachi, Aaliya; Javeed, Imaan; Hamel, Paul A

    2016-08-19

    The Hedgehog (Hh) pathway is a highly conserved signaling cascade crucial for cell fate determination during embryogenesis. Response to the Hh ligands is mediated by the receptor Patched-1 (Ptch1), a 12-pass transmembrane glycoprotein. Despite its essential role in Hh signaling and its activity as a tumor suppressor, Ptch1 remains largely uncharacterized. We demonstrate here that Ptch1 binds to itself to form oligomeric structures. Oligomerization is mediated by two distinct, structurally disordered, intracellular domains spanning amino acids 584-734 ("middle loop") and 1162-1432 (C terminus). However, oligomerization is not required for Ptch1-dependent regulation of the canonical Hh pathway operating through Smo. Expression of a mutant protein that deletes both regions represses the Hh pathway and responds to the addition of Hh ligand independent of its inability to bind other factors such as Smurf2. Additionally, deletion of the cytoplasmic middle loop domain generates a Ptch1 mutant that, despite binding to Hh ligand, constitutively suppresses Hh signaling and increases the length of primary cilia. Constitutive activity because of deletion of this region is reversed by further deletion of specific sequences in the cytoplasmic C-terminal domain. These data reveal an interaction between the cytoplasmic domains of Ptch1 and that these domains modulate Ptch1 activity but are not essential for regulation of the Hh pathway. PMID:27325696

  8. Activities of the Cytoplasmic Domains of Patched-1 Modulate but Are Not Essential for the Regulation of Canonical Hedgehog Signaling.

    PubMed

    Fleet, Andrew; Lee, Jennifer P Y; Tamachi, Aaliya; Javeed, Imaan; Hamel, Paul A

    2016-08-19

    The Hedgehog (Hh) pathway is a highly conserved signaling cascade crucial for cell fate determination during embryogenesis. Response to the Hh ligands is mediated by the receptor Patched-1 (Ptch1), a 12-pass transmembrane glycoprotein. Despite its essential role in Hh signaling and its activity as a tumor suppressor, Ptch1 remains largely uncharacterized. We demonstrate here that Ptch1 binds to itself to form oligomeric structures. Oligomerization is mediated by two distinct, structurally disordered, intracellular domains spanning amino acids 584-734 ("middle loop") and 1162-1432 (C terminus). However, oligomerization is not required for Ptch1-dependent regulation of the canonical Hh pathway operating through Smo. Expression of a mutant protein that deletes both regions represses the Hh pathway and responds to the addition of Hh ligand independent of its inability to bind other factors such as Smurf2. Additionally, deletion of the cytoplasmic middle loop domain generates a Ptch1 mutant that, despite binding to Hh ligand, constitutively suppresses Hh signaling and increases the length of primary cilia. Constitutive activity because of deletion of this region is reversed by further deletion of specific sequences in the cytoplasmic C-terminal domain. These data reveal an interaction between the cytoplasmic domains of Ptch1 and that these domains modulate Ptch1 activity but are not essential for regulation of the Hh pathway.

  9. Vismodegib, an antagonist of hedgehog signaling, directly alters taste molecular signaling in taste buds.

    PubMed

    Yang, Hyekyung; Cong, Wei-Na; Yoon, Jeong Seon; Egan, Josephine M

    2015-02-01

    Vismodegib, a highly selective inhibitor of hedgehog (Hh) pathway, is an approved treatment for basal-cell carcinoma. Patients on treatment with vismodegib often report profound alterations in taste sensation. The cellular mechanisms underlying the alterations have not been studied. Sonic Hh (Shh) signaling is required for cell growth and differentiation. In taste buds, Shh is exclusively expressed in type IV taste cells, which are undifferentiated basal cells and the precursors of the three types of taste sensing cells. Thus, we investigated if vismodegib has an inhibitory effect on taste cell turnover because of its known effects on Hh signaling. We gavaged C57BL/6J male mice daily with either vehicle or 30 mg/kg vismodegib for 15 weeks. The gustatory behavior and immunohistochemical profile of taste cells were examined. Vismodegib-treated mice showed decreased growth rate and behavioral responsivity to sweet and bitter stimuli, compared to vehicle-treated mice. We found that vismodegib-treated mice had significant reductions in taste bud size and numbers of taste cells per taste bud. Additionally, vismodegib treatment resulted in decreased numbers of Ki67- and Shh-expressing cells in taste buds. The numbers of phospholipase Cβ2- and α-gustducin-expressing cells, which contain biochemical machinery for sweet and bitter sensing, were reduced in vismodegib-treated mice. Furthermore, vismodegib treatment resulted in reduction in numbers of T1R3, glucagon-like peptide-1, and glucagon-expressing cells, which are known to modulate sweet taste sensitivity. These results suggest that inhibition of Shh signaling by vismodegib treatment directly results in alteration of taste due to local effects in taste buds.

  10. Stromal Hedgehog signalling is downregulated in colon cancer and its restoration restrains tumour growth

    PubMed Central

    Gerling, Marco; Büller, Nikè V. J. A.; Kirn, Leonard M.; Joost, Simon; Frings, Oliver; Englert, Benjamin; Bergström, Åsa; Kuiper, Raoul V.; Blaas, Leander; Wielenga, Mattheus C. B.; Almer, Sven; Kühl, Anja A.; Fredlund, Erik; van den Brink, Gijs R.; Toftgård, Rune

    2016-01-01

    A role for Hedgehog (Hh) signalling in the development of colorectal cancer (CRC) has been proposed. In CRC and other solid tumours, Hh ligands are upregulated; however, a specific Hh antagonist provided no benefit in a clinical trial. Here we use Hh reporter mice to show that downstream Hh activity is unexpectedly diminished in a mouse model of colitis-associated colon cancer, and that downstream Hh signalling is restricted to the stroma. Functionally, stroma-specific Hh activation in mice markedly reduces the tumour load and blocks progression of advanced neoplasms, partly via the modulation of BMP signalling and restriction of the colonic stem cell signature. By contrast, attenuated Hh signalling accelerates colonic tumourigenesis. In human CRC, downstream Hh activity is similarly reduced and canonical Hh signalling remains predominantly paracrine. Our results suggest that diminished downstream Hh signalling enhances CRC development, and that stromal Hh activation can act as a colonic tumour suppressor. PMID:27492255

  11. Hedgehog signaling regulates FOXA2 in esophageal embryogenesis and Barrett’s metaplasia

    PubMed Central

    Wang, David H.; Tiwari, Anjana; Kim, Monica E.; Clemons, Nicholas J.; Regmi, Nanda L.; Hodges, William A.; Berman, David M.; Montgomery, Elizabeth A.; Watkins, D. Neil; Zhang, Xi; Zhang, Qiuyang; Jie, Chunfa; Spechler, Stuart J.; Souza, Rhonda F.

    2014-01-01

    Metaplasia can result when injury reactivates latent developmental signaling pathways that determine cell phenotype. Barrett’s esophagus is a squamous-to-columnar epithelial metaplasia caused by reflux esophagitis. Hedgehog (Hh) signaling is active in columnar-lined, embryonic esophagus and inactive in squamous-lined, adult esophagus. We showed previously that Hh signaling is reactivated in Barrett’s metaplasia and overexpression of Sonic hedgehog (SHH) in mouse esophageal squamous epithelium leads to a columnar phenotype. Here, our objective was to identify Hh target genes involved in Barrett’s pathogenesis. By microarray analysis, we found that the transcription factor Foxa2 is more highly expressed in murine embryonic esophagus compared with postnatal esophagus. Conditional activation of Shh in mouse esophageal epithelium induced FOXA2, while FOXA2 expression was reduced in Shh knockout embryos, establishing Foxa2 as an esophageal Hh target gene. Evaluation of patient samples revealed FOXA2 expression in Barrett’s metaplasia, dysplasia, and adenocarcinoma but not in esophageal squamous epithelium or squamous cell carcinoma. In esophageal squamous cell lines, Hh signaling upregulated FOXA2, which induced expression of MUC2, an intestinal mucin found in Barrett’s esophagus, and the MUC2-processing protein AGR2. Together, these data indicate that Hh signaling induces expression of genes that determine an intestinal phenotype in esophageal squamous epithelial cells and may contribute to the development of Barrett’s metaplasia. PMID:25083987

  12. Odontogenic Keratocysts Arise from Quiescent Epithelial Rests and Are Associated with Deregulated Hedgehog Signaling in Mice and Humans

    PubMed Central

    Grachtchouk, Marina; Liu, Jianhong; Wang, Aiqin; Wei, Lebing; Bichakjian, Christopher K.; Garlick, Jonathan; Paulino, Augusto F.; Giordano, Thomas; Dlugosz, Andrzej A.

    2006-01-01

    Odontogenic keratocysts in humans are aggressive, noninflammatory jaw cysts that may harbor PTCH1 mutations, leading to constitutive activity of the embryonic Hedgehog (Hh) signaling pathway. We show here that epithelial expression of the Hh transcriptional effector Gli2 is sufficient for highly penetrant keratocyst development in transgenic mice. Mouse and human keratocysts expressed similar markers, leading to tooth misalignment, bone remodeling, and craniofacial abnormalities. We detected Hh target gene expression in epithelial cells lining keratocysts from both species, implicating deregulated Hh signaling in their development. Most mouse keratocysts arose from rests of Malassez—quiescent, residual embryonic epithelial cells that remain embedded in the periodontal ligament surrounding mature teeth. In Gli2-expressing mice, these rests were stimulated to proliferate, stratify, and form a differentiated squamous epithelium. The frequent development of keratocysts in Gli2-expressing mice supports the idea that GLI transcription factor activity mediates pathological responses to deregulated Hh signaling in humans. Moreover, Gli2-mediated reactivation of quiescent epithelial rests to form keratocysts indicates that these cells retain the capacity to function as progenitor cells on activation by an appropriate developmental signal. PMID:16936257

  13. A Smoothened-Evc2 complex transduces the Hedgehog signal at primary cilia.

    PubMed

    Dorn, Karolin V; Hughes, Casey E; Rohatgi, Rajat

    2012-10-16

    Vertebrate Hedgehog (Hh) signaling is initiated at primary cilia by the ligand-triggered accumulation of Smoothened (Smo) in the ciliary membrane. The underlying biochemical mechanisms remain unknown. We find that Hh agonists promote the association between Smo and Evc2, a ciliary protein that is defective in two human ciliopathies. The formation of the Smo-Evc2 complex is under strict spatial control, being restricted to a distinct ciliary compartment, the EvC zone. Mutant Evc2 proteins that localize in cilia but are displaced from the EvC zone are dominant inhibitors of Hh signaling. Disabling Evc2 function blocks Hh signaling at a specific step between Smo and the downstream regulators protein kinase A and Suppressor of Fused, preventing activation of the Gli transcription factors. Our data suggest that the Smo-Evc2 signaling complex at the EvC zone is required for Hh signal transmission and elucidate the molecular basis of two human ciliopathies.

  14. Tachykinin acts upstream of autocrine Hedgehog signaling during nociceptive sensitization in Drosophila

    PubMed Central

    Im, Seol Hee; Takle, Kendra; Jo, Juyeon; Babcock, Daniel T; Ma, Zhiguo; Xiang, Yang; Galko, Michael J

    2015-01-01

    Pain signaling in vertebrates is modulated by neuropeptides like Substance P (SP). To determine whether such modulation is conserved and potentially uncover novel interactions between nociceptive signaling pathways we examined SP/Tachykinin signaling in a Drosophila model of tissue damage-induced nociceptive hypersensitivity. Tissue-specific knockdowns and genetic mutant analyses revealed that both Tachykinin and Tachykinin-like receptor (DTKR99D) are required for damage-induced thermal nociceptive sensitization. Electrophysiological recording showed that DTKR99D is required in nociceptive sensory neurons for temperature-dependent increases in firing frequency upon tissue damage. DTKR overexpression caused both behavioral and electrophysiological thermal nociceptive hypersensitivity. Hedgehog, another key regulator of nociceptive sensitization, was produced by nociceptive sensory neurons following tissue damage. Surprisingly, genetic epistasis analysis revealed that DTKR function was upstream of Hedgehog-dependent sensitization in nociceptive sensory neurons. Our results highlight a conserved role for Tachykinin signaling in regulating nociception and the power of Drosophila for genetic dissection of nociception. DOI: http://dx.doi.org/10.7554/eLife.10735.001 PMID:26575288

  15. Tachykinin acts upstream of autocrine Hedgehog signaling during nociceptive sensitization in Drosophila.

    PubMed

    Im, Seol Hee; Takle, Kendra; Jo, Juyeon; Babcock, Daniel T; Ma, Zhiguo; Xiang, Yang; Galko, Michael J

    2015-11-17

    Pain signaling in vertebrates is modulated by neuropeptides like Substance P (SP). To determine whether such modulation is conserved and potentially uncover novel interactions between nociceptive signaling pathways we examined SP/Tachykinin signaling in a Drosophila model of tissue damage-induced nociceptive hypersensitivity. Tissue-specific knockdowns and genetic mutant analyses revealed that both Tachykinin and Tachykinin-like receptor (DTKR99D) are required for damage-induced thermal nociceptive sensitization. Electrophysiological recording showed that DTKR99D is required in nociceptive sensory neurons for temperature-dependent increases in firing frequency upon tissue damage. DTKR overexpression caused both behavioral and electrophysiological thermal nociceptive hypersensitivity. Hedgehog, another key regulator of nociceptive sensitization, was produced by nociceptive sensory neurons following tissue damage. Surprisingly, genetic epistasis analysis revealed that DTKR function was upstream of Hedgehog-dependent sensitization in nociceptive sensory neurons. Our results highlight a conserved role for Tachykinin signaling in regulating nociception and the power of Drosophila for genetic dissection of nociception.

  16. Inhibition of Hedgehog-Signaling Driven Genes in Prostate Cancer Cells by Sutherlandia frutescens Extract.

    PubMed

    Lu, Yuan; Starkey, Nicholas; Lei, Wei; Li, Jilong; Cheng, Jianlin; Folk, William R; Lubahn, Dennis B

    2015-01-01

    Sutherlandia frutescens (L) R. Br. (Sutherlandia) is a South African botanical that is traditionally used to treat a variety of health conditions, infections and diseases, including cancer. We hypothesized Sutherlandia might act through Gli/ Hedgehog (Hh)-signaling in prostate cancer cells and used RNA-Seq transcription profiling to profile gene expression in TRAMPC2 murine prostate cancer cells with or without Sutherlandia extracts. We found 50% of Hh-responsive genes can be repressed by Sutherlandia ethanol extract, including the canonical Hh-responsive genes Gli1 and Ptch1 as well as newly distinguished Hh-responsive genes Hsd11b1 and Penk. PMID:26710108

  17. Hedgehog Signaling Modulates the Release of Gliotransmitters from Cultured Cerebellar Astrocytes.

    PubMed

    Okuda, Hiroaki; Tatsumi, Kouko; Morita-Takemura, Shoko; Nakahara, Kazuki; Nochioka, Katsunori; Shinjo, Takeaki; Terada, Yuki; Wanaka, Akio

    2016-02-01

    Sonic hedgehog (Shh), a member of the Hedgehog (Hh) family, plays essential roles in the development of the central nervous system. Recent studies suggest that the Hh signaling pathway also functions in mature astrocytes under physiological conditions. We first examined the expression of genes encoding Hh signaling molecules in the adult mouse cerebellum by in situ hybridization histochemistry. mRNA for Patched homolog 1 (Ptch1), a receptor for Hh family members, was expressed in S100β-positive astrocytes and Shh mRNA was expressed in HuC/D-positive neurons, implying that the Hh signaling pathway contributes to neuro-glial interactions. To test this hypothesis, we next examined the effects of recombinant SHH N-terminal protein (rSHH-N) on the functions of cultured cerebellar astrocytes. rSHH-N up-regulated Hh signal target genes such as Ptch1 and Gli-1, a key transcription factor of the Hh signaling pathway. Although activation of Hh signaling by rSHH-N or purmorphamine influenced neither glutamate uptake nor gliotransmitters release, inhibition of the Hh signaling pathway by cyclopamine, neutralizing antibody against SHH or intracellular Ca(2+) chelation decreased glutamate and ATP release from cultured cerebellar astrocytes. On the other hand, cyclopamine, neutralizing antibody against SHH or Ca(2+) chelator hardly affected D-serine secretion. Various kinase inhibitors attenuated glutamate and ATP release, while only U0126 reduced D-serine secretion from the astrocytes. These results suggested that the Hh signaling pathway sustains the release of glutamate and ATP and participates in neuro-glial interactions in the adult mouse brain. We also propose that signaling pathways distinct from the Hh pathway govern D-serine secretion from adult cerebellar astrocytes. PMID:26694649

  18. Hedgehog Signaling Regulates the Ciliary Transport of Odorant Receptors in Drosophila.

    PubMed

    Sanchez, Gonzalo M; Alkhori, Liza; Hatano, Eduardo; Schultz, Sebastian W; Kuzhandaivel, Anujaianthi; Jafari, Shadi; Granseth, Björn; Alenius, Mattias

    2016-01-26

    Hedgehog (Hh) signaling is a key regulatory pathway during development and also has a functional role in mature neurons. Here, we show that Hh signaling regulates the odor response in adult Drosophila olfactory sensory neurons (OSNs). We demonstrate that this is achieved by regulating odorant receptor (OR) transport to and within the primary cilium in OSN neurons. Regulation relies on ciliary localization of the Hh signal transducer Smoothened (Smo). We further demonstrate that the Hh- and Smo-dependent regulation of the kinesin-like protein Cos2 acts in parallel to the intraflagellar transport system (IFT) to localize ORs within the cilium compartment. These findings expand our knowledge of Hh signaling to encompass chemosensory modulation and receptor trafficking.

  19. Hedgehog Signaling Regulates the Survival of Gastric Cancer Cells by Regulating the Expression of Bcl-2

    PubMed Central

    Han, Myoung-Eun; Lee, Young-Suk; Baek, Sun-Yong; Kim, Bong-Seon; Kim, Jae-Bong; Oh, Sae-Ock

    2009-01-01

    Gastric cancer is the second most common cause of cancer deaths worldwide. The underlying molecular mechanisms of its carcinogenesis are relatively poorly characterized. Hedgehog (Hh) signaling, which is critical for development of various organs including the gastrointestinal tract, has been associated with gastric cancer. The present study was undertaken to reveal the underlying mechanism by which Hh signaling controls gastric cancer cell proliferation. Treatment of gastric cancer cells with cyclopamine, a specific inhibitor of Hh signaling pathway, reduced proliferation and induced apoptosis of gastric cancer cells. Cyclopamine treatment induced cytochrome c release from mitochondria and cleavage of caspase 9. Moreover, Bcl-2 expression was significantly reduced by cyclopamine treatment. These results suggest that Hh signaling regulates the survival of gastric cancer cells by regulating the expression of Bcl-2. PMID:19742123

  20. Integration of telencephalic Wnt and hedgehog signaling center activities by Foxg1.

    PubMed

    Danesin, Catherine; Peres, João N; Johansson, Marie; Snowden, Victoria; Cording, Amy; Papalopulu, Nancy; Houart, Corinne

    2009-04-01

    The forebrain is patterned along the dorsoventral (DV) axis by Sonic Hedgehog (Shh). However, previous studies have suggested the presence of an Shh-independent mechanism. Our study identifies Wnt/beta-catenin-activated from the telencephalic roof-as an Shh-independent pathway that is essential for telencephalic pallial (dorsal) specification during neurulation. We demonstrate that the transcription factor Foxg1 coordinates the activity of two signaling centers: Foxg1 is a key downstream effector of the Shh pathway during induction of subpallial (ventral) identity, and it inhibits Wnt/beta-catenin signaling through direct transcriptional repression of Wnt ligands. This inhibition restricts the dorsal Wnt signaling center to the roof plate and consequently limits pallial identities. Concomitantly to these roles, Foxg1 controls the formation of the compartment boundary between telencephalon and basal diencephalon. Altogether, these findings identify a key direct target of Foxg1, and uncover a simple molecular mechanism by which Foxg1 integrates two opposing signaling centers.

  1. Zfp423 Regulates Sonic Hedgehog Signaling via Primary Cilium Function

    PubMed Central

    Hamilton, Bruce A.

    2016-01-01

    Zfp423 encodes a 30-zinc finger transcription factor that intersects several canonical signaling pathways. Zfp423 mutations result in ciliopathy-related phenotypes, including agenesis of the cerebellar vermis in mice and Joubert syndrome (JBTS19) and nephronophthisis (NPHP14) in humans. Unlike most ciliopathy genes, Zfp423 encodes a nuclear protein and its developmental expression is complex, leading to alternative proposals for cellular mechanisms. Here we show that Zfp423 is expressed by cerebellar granule cell precursors, that loss of Zfp423 in these precursors leads to cell-intrinsic reduction in proliferation, loss of response to Shh, and primary cilia abnormalities that include diminished frequency of both Smoothened and IFT88 localization. Loss of Zfp423 alters expression of several genes encoding key cilium components, including increased expression of Tulp3. Tulp3 is a direct binding target of Zfp423 and reducing the overexpression of Tulp3 in Zfp423-deficient cells suppresses Smoothened translocation defects. These results define Zfp423 deficiency as a bona fide ciliopathy, acting upstream of Shh signaling, and indicate a mechanism intrinsic to granule cell precursors for the resulting cerebellar hypoplasia. PMID:27727273

  2. The Role of Sonic Hedgehog Signaling in Osteoclastogenesis and Jaw Bone Destruction.

    PubMed

    Shimo, Tsuyoshi; Matsumoto, Kenichi; Takabatake, Kiyofumi; Aoyama, Eriko; Takebe, Yuichiro; Ibaragi, Soichiro; Okui, Tatsuo; Kurio, Naito; Takada, Hiroyuki; Obata, Kyoichi; Pang, Pai; Iwamoto, Masahiro; Nagatsuka, Hitoshi; Sasaki, Akira

    2016-01-01

    Sonic hedgehog (SHH) and its signaling have been identified in several human cancers, and increased levels of its expression appear to correlate with disease progression and metastasis. However, the role of SHH in bone destruction associated with oral squamous cell carcinomas is still unclear. In this study we analyzed SHH expression and the role played by SHH signaling in gingival carcinoma-induced jawbone destruction. From an analysis of surgically resected lower gingival squamous cell carcinoma mandible samples, we found that SHH was highly expressed in tumor cells that had invaded the bone matrix. On the other hand, the hedgehog receptor Patched and the signaling molecule Gli-2 were highly expressed in the osteoclasts and the progenitor cells. SHH stimulated osteoclast formation and pit formation in the presence of the receptor activator for nuclear factor-κB ligand (RANKL) in CD11b+ mouse bone marrow cells. SHH upregulated phosphorylation of ERK1/2 and p38 MAPK, NFATc1, tartrate-resistant acid phosphatase (TRAP), and Cathepsin K expression in RAW264.7 cells. Our results suggest that tumor-derived SHH stimulated the osteoclast formation and bone resorption in the tumor jawbone microenvironment. PMID:27007126

  3. The Role of Sonic Hedgehog Signaling in Osteoclastogenesis and Jaw Bone Destruction

    PubMed Central

    Shimo, Tsuyoshi; Matsumoto, Kenichi; Takabatake, Kiyofumi; Aoyama, Eriko; Takebe, Yuichiro; Ibaragi, Soichiro; Okui, Tatsuo; Kurio, Naito; Takada, Hiroyuki; Obata, Kyoichi; Pang, Pai; Iwamoto, Masahiro; Nagatsuka, Hitoshi; Sasaki, Akira

    2016-01-01

    Sonic hedgehog (SHH) and its signaling have been identified in several human cancers, and increased levels of its expression appear to correlate with disease progression and metastasis. However, the role of SHH in bone destruction associated with oral squamous cell carcinomas is still unclear. In this study we analyzed SHH expression and the role played by SHH signaling in gingival carcinoma-induced jawbone destruction. From an analysis of surgically resected lower gingival squamous cell carcinoma mandible samples, we found that SHH was highly expressed in tumor cells that had invaded the bone matrix. On the other hand, the hedgehog receptor Patched and the signaling molecule Gli-2 were highly expressed in the osteoclasts and the progenitor cells. SHH stimulated osteoclast formation and pit formation in the presence of the receptor activator for nuclear factor-κB ligand (RANKL) in CD11b+ mouse bone marrow cells. SHH upregulated phosphorylation of ERK1/2 and p38 MAPK, NFATc1, tartrate-resistant acid phosphatase (TRAP), and Cathepsin K expression in RAW264.7 cells. Our results suggest that tumor-derived SHH stimulated the osteoclast formation and bone resorption in the tumor jawbone microenvironment. PMID:27007126

  4. Hedgehog signaling regulates E-cadherin expression for the maintenance of the actin cytoskeleton and tight junctions.

    PubMed

    Xiao, Chang; Ogle, Sally A; Schumacher, Michael A; Schilling, Neal; Tokhunts, Robert A; Orr-Asman, Melissa A; Miller, Marian L; Robbins, David J; Hollande, Frederic; Zavros, Yana

    2010-12-01

    In the stomach, strictly regulated cell adherens junctions are crucial in determining epithelial cell differentiation. Sonic Hedgehog (Shh) regulates epithelial cell differentiation in the adult stomach. We sought to identify whether Shh plays a role in regulating adherens junction protein E-cadherin as a mechanism for epithelial cell differentiation. Mouse nontumorigenic gastric epithelial (IMGE-5) cells treated with Hedgehog signaling inhibitor cyclopamine and anti-Shh 5E1 antibody or transduced with short hairpin RNA against Skinny Hedgehog (IMGE-5(Ski)) were cultured. A mouse model expressing a parietal cell-specific deletion of Shh (HKCre/Shh(KO)) was used to identify further changes in adherens and tight junctions. Inhibition of Hedgehog signaling in IMGE-5 cells caused loss of E-cadherin expression accompanied by disruption of F-actin cortical expression and relocalization of zonula occludens-1 (ZO-1). Loss of E-cadherin was also associated with increased proliferation in IMGE-5(Ski) cells and increased expression of the mucous neck cell lineage marker MUC6. Compared with membrane-expressed E-cadherin and ZO-1 protein in controls, dissociation of E-cadherin/β-catenin and ZO-1/occludin protein complexes was observed in HKCre/Shh(KO) mice. In conclusion, we demonstrate that Hedgehog signaling regulates E-cadherin expression that is required for the maintenance of F-actin cortical expression and stability of tight junction protein ZO-1.

  5. Hedgehog signal activation coordinates proliferation and differentiation of fetal liver progenitor cells

    SciTech Connect

    Hirose, Yoshikazu; Itoh, Tohru; Miyajima, Atsushi

    2009-09-10

    Hedgehog (Hh) signaling plays crucial roles in development and homeostasis of various organs. In the adult liver, it regulates proliferation and/or viability of several types of cells, particularly under injured conditions, and is also implicated in stem/progenitor cell maintenance. However, the role of this signaling pathway during the normal developmental process of the liver remains elusive. Although Sonic hedgehog (Shh) is expressed in the ventral foregut endoderm from which the liver derives, the expression disappears at the onset of the liver bud formation, and its possible recurrence at the later stages has not been investigated. Here we analyzed the activation and functional relevance of Hh signaling during the mouse fetal liver development. At E11.5, Shh and an activation marker gene for Hh signaling, Gli1, were expressed in Dlk{sup +} hepatoblasts, the fetal liver progenitor cells, and the expression was rapidly decreased thereafter as the development proceeded. In the culture of Dlk{sup +} hepatoblasts isolated from the E11.5 liver, activation of Hh signaling stimulated their proliferation and this effect was cancelled by a chemical Hh signaling inhibitor, cyclopamine. In contrast, hepatocyte differentiation of Dlk{sup +} hepatoblasts in vitro as manifested by the marker gene expression and acquisition of ammonia clearance activity was significantly inhibited by forced activation of Hh signaling. Taken together, these results demonstrate the temporally restricted manner of Hh signal activation and its role in promoting the hepatoblast proliferation, and further suggest that the pathway needs to be shut off for the subsequent hepatic differentiation of hepatoblasts to proceed normally.

  6. Targeting of sonic hedgehog-Gli signaling: A potential therapeutic target for patients with breast cancer

    PubMed Central

    Song, Lingqin; Wang, Weifeng; Liu, Di; Zhao, Yang; He, Jianjun; Wang, Xijing; Dai, Zhijun; Zhang, Huimin; Li, Xiao

    2016-01-01

    Breast cancer is the most common malignant cancer among women. The Hedgehog (Hh) signaling pathway serves a key role in malignant cancer cell growth and migration. However, little is known with regard to the specific function of the Hh signaling pathway in human breast cancer. The current study investigated the specific role of Hh signaling in the human breast cancer cell line MDA-MB-231. Expression of components of Shh-Gli signaling, as well as the Gli-responsive genes B-cell lymphoma 2 (Bcl-2) and cyclin D1, were investigated in MDA-MB-231 cells using western blotting. The effects of Shh-Gli signaling on MDA-MB-231 proliferation were analyzed by MTT assay. The role of E-cadherin in the epithelial-mesenchymal transition process was determined by western blot while matrix metalloproteinase (MMP)-9/MMP-2 secretion was studied by enzyme-linked immunosorbent assay. The results indicated that Shh-Gli signaling was activated in MDA-MB-231 cells, significantly enhancing cell viability. Overexpression of Gli positively regulated the transcription of Bcl-2 and cyclin D1 thereby regulating MDA-MB-231 cell proliferation and survival. Treatment of MDA-MB-231 cells with human sonic hedgehog, n-terminus for 72 h significantly reduced E-cadherin protein levels and enhanced secretion of MMP-9 and MMP-2. These findings suggest that Shh-Gli signaling is significantly activated in human breast cancer cells, and is accompanied by enhanced cell viability, proliferation and migration capacities. PMID:27446389

  7. Low-level Ga-Al-As laser irradiation enhances osteoblast proliferation through activation of Hedgehog signaling pathway

    NASA Astrophysics Data System (ADS)

    Li, Qiushi; Qu, Zhou; Chen, Yingxin; Liu, Shujie; Zhou, Yanmin

    2014-12-01

    Low-level laser irradiation has been reported to promote bone formation, but the molecular mechanism is still unclear. Hedgehog signaling pathway has been reported to play an important role in promoting bone formation. The aim of the present study was to examine whether low-level Ga-Al-As laser (808 nm) irradiation could have an effect on Hedgehog signaling pathway during osteoblast proliferation in vitro. Mouse osteoblastic cell line MC3T3-E1 was cultured in vitro. The cultures after laser irradiation (3.75J/cm2) were treated with recombinant N-terminals Sonic Hedgehog (N-Shh)or Hedgehog inhibitor cyclopamine (cy). The experiment was divided into 4 group, group 1:laser irradiation, group 2: laser irradiation and N-Shh, group 3: laser irradiation and cy, group 4:control with no laser irradiation. On day 1,2 and 3,cell proliferation was determined by cell counting, Cell Counting Kit-8.On 12 h and 24 h, cell cycle was detected by flow cytometry. Proliferation activity of laser irradiation and N-Shh group was remarkably increased compared with those of laser irradiation group. Proliferation activity of laser irradiation and cy group was remarkably decreased compared with those of laser irradiation group, however proliferation activity of laser irradiation and cy group was remarkably increased compared with those of control group. These results suggest that low-level Ga-Al-As laser irradiation activate Hedgehog signaling pathway during osteoblast proliferation in vitro. Hedgehog signaling pathway is one of the signaling pathways by which low-level Ga-Al-As laser irradiation regulates osteoblast proliferation.

  8. The Hedgehog Signalling Pathway in Cell Migration and Guidance: What We Have Learned from Drosophila melanogaster

    PubMed Central

    Araújo, Sofia J.

    2015-01-01

    Cell migration and guidance are complex processes required for morphogenesis, the formation of tumor metastases, and the progression of human cancer. During migration, guidance molecules induce cell directionality and movement through complex intracellular mechanisms. Expression of these molecules has to be tightly regulated and their signals properly interpreted by the receiving cells so as to ensure correct navigation. This molecular control is fundamental for both normal morphogenesis and human disease. The Hedgehog (Hh) signaling pathway is evolutionarily conserved and known to be crucial for normal cellular growth and differentiation throughout the animal kingdom. The relevance of Hh signaling for human disease is emphasized by its activation in many cancers. Here, I review the current knowledge regarding the involvement of the Hh pathway in cell migration and guidance during Drosophila development and discuss its implications for human cancer origin and progression. PMID:26445062

  9. A PTCH1 homolog transcriptionally activated by p53 suppresses Hedgehog signaling.

    PubMed

    Chung, Jon H; Larsen, Andrew R; Chen, Evan; Bunz, Fred

    2014-11-21

    The p53-mediated responses to DNA damage and the Hedgehog (Hh) signaling pathway are each recurrently dysregulated in many types of human cancer. Here we describe PTCH53, a p53 target gene that is homologous to the tumor suppressor gene PTCH1 and can function as a repressor of Hh pathway activation. PTCH53 (previously designated PTCHD4) was highly responsive to p53 in vitro and was among a small number of genes that were consistently expressed at reduced levels in diverse TP53 mutant cell lines and human tumors. Increased expression of PTCH53 inhibited canonical Hh signaling by the G protein-coupled receptor SMO. PTCH53 thus delineates a novel, inducible pathway by which p53 can repress tumorigenic Hh signals. PMID:25296753

  10. A PTCH1 Homolog Transcriptionally Activated by p53 Suppresses Hedgehog Signaling*

    PubMed Central

    Chung, Jon H.; Larsen, Andrew R.; Chen, Evan; Bunz, Fred

    2014-01-01

    The p53-mediated responses to DNA damage and the Hedgehog (Hh) signaling pathway are each recurrently dysregulated in many types of human cancer. Here we describe PTCH53, a p53 target gene that is homologous to the tumor suppressor gene PTCH1 and can function as a repressor of Hh pathway activation. PTCH53 (previously designated PTCHD4) was highly responsive to p53 in vitro and was among a small number of genes that were consistently expressed at reduced levels in diverse TP53 mutant cell lines and human tumors. Increased expression of PTCH53 inhibited canonical Hh signaling by the G protein-coupled receptor SMO. PTCH53 thus delineates a novel, inducible pathway by which p53 can repress tumorigenic Hh signals. PMID:25296753

  11. FOXC1 Activates Smoothened-Independent Hedgehog Signaling in Basal-like Breast Cancer

    PubMed Central

    Han, Bingchen; Qu, Ying; Jin, Yanli; Yu, Yi; Deng, Nan; Wawrowsky, Kolja; Zhang, Xiao; Li, Na; Bose, Shikha; Wang, Qiang; Sakkiah, Sugunadevi; Abrol, Ravinder; Jensen, Tor W.; Berman, Benjamin; Tanaka, Hisashi; Johnson, Jeffrey; Gao, Bowen; Hao, Jijun; Liu, Zhenqiu; Buttyan, Ralph; Ray, Partha S.; Hung, Mien-Chie; Giuliano, Armando E.; Cui, Xiaojiang

    2015-01-01

    Summary The mesoderm- and epithelial-mesenchymal transition-associated transcription factor FOXC1 is specifically overexpressed in basal-like breast cancer (BLBC), but its biochemical function is not understood. Here we demonstrate that FOXC1 controls cancer stem cell (CSC) properties enriched in BLBC cells via activation of Smoothened (SMO)-independent Hedgehog (Hh) signaling. This non-canonical activation of Hh is specifically mediated by Gli2. We further show that the N-terminal domain of FOXC1 (aa 1–68) binds directly to an internal region (aa 898–1168) of Gli2, enhancing the DNA-binding and transcription-activating capacity of Gli2. FOXC1 expression correlates with that of Gli2 and its targets in human breast cancers. Moreover, FOXC1 overexpression reduces sensitivity to anti-Hedgehog (Hh) inhibitors in BLBC cells and xenograft tumors. Together, these findings reveal FOXC1-mediated non-canonical Hh signaling that determines the BLBC stem-like phenotype and anti-Hh sensitivity, supporting inhibition of FOXC1 pathways as potential approaches for improving BLBC treatment. PMID:26565916

  12. Chloroquine targets pancreatic cancer stem cells via inhibition of CXCR4 and hedgehog signaling.

    PubMed

    Balic, Anamaria; Sørensen, Morten Dræby; Trabulo, Sara Maria; Sainz, Bruno; Cioffi, Michele; Vieira, Catarina R; Miranda-Lorenzo, Irene; Hidalgo, Manuel; Kleeff, Joerg; Erkan, Mert; Heeschen, Christopher

    2014-07-01

    Pancreatic ductal adenocarcinoma is one of the deadliest carcinomas and is characterized by highly tumorigenic and metastatic cancer stem cells (CSC). CSCs evade available therapies, which preferentially target highly proliferative and more differentiated progenies, leaving behind CSCs as a putative source for disease relapse. Thus, to identify potentially more effective treatment regimens, we screened established and new compounds for their ability to eliminate CSCs in primary pancreatic cancer (stem) cells in vitro and corresponding patient-derived pancreatic cancer tissue xenografts in vivo. Intriguingly, we found that in vitro treatment with the antimalarial agent chloroquine significantly decreased CSCs, translating into diminished in vivo tumorigenicity and invasiveness in a large panel of pancreatic cancers. In vivo treatment in combination with gemcitabine was capable of more effectively eliminating established tumors and improved overall survival. The inhibitory effect of chloroquine was not related to inhibition of autophagy, but was due to inhibition of CXCL12/CXCR4 signaling, resulting in reduced phosphorylation of ERK and STAT3. Furthermore, chloroquine showed potent inhibition of hedgehog signaling by decreasing the production of Smoothened, translating into a significant reduction in sonic hedgehog-induced chemotaxis and downregulation of downstream targets in CSCs and the surrounding stroma. Our study demonstrates that via to date unreported effects, chloroquine is an effective adjuvant therapy to chemotherapy, offering more efficient tumor elimination and improved cure rates. Chloroquine should be further explored in the clinical setting as its success may help to more rapidly improve the poor prognosis of patients with pancreatic cancer. PMID:24785258

  13. Survivin, a novel target of the Hedgehog/GLI signaling pathway in human tumor cells.

    PubMed

    Vlčková, K; Ondrušová, L; Vachtenheim, J; Réda, J; Dundr, P; Zadinová, M; Žáková, P; Poučková, P

    2016-01-01

    Survivin, an important antiapoptotic protein, is expressed in tumors, whereas in normal tissues the expression of this protein is extremely low, defining a role for survivin as a cancer gene. Survivin exhibits multifunctional activity in tumor cells. However, why survivin expression is sharply and invariably restricted to tumor tissue remains unclear. Here, we identified 11 putative consensus binding sites for GLI transcription factors in the survivin promoter and characterized the promoter activity. Inhibitors of the Hedgehog/GLI pathway, cyclopamine and GANT61, decreased the promoter activity in reporter assays. ΔNGLI2 (which lacks the repressor domain) was the most potent vector in activating the survivin promoter-reporter. Moreover, GANT61, a GLI1/2 inhibitor, repressed endogenous survivin protein and mRNA expression in most cells across a large panel of tumor cell lines. Chromatin immunoprecipitation showed GLI2 binding to the survivin promoter. The ectopic GLI2-evoked expression of endogenous survivin was observed in normal human fibroblasts. GANT61 decreased survivin level in nude mice tumors, mimicking the activity of GANT61 in cultured cells. The immunohistochemistry and double immunofluorescence of human tumors revealed a correlation between the tissue regions showing high GLI2 and survivin positivity. Thus, these results demonstrated that survivin is a classical transcriptional target of GLI2, a Hedgehog pathway signaling effector. This potentially reflects the high expression of survivin in human tumor cells. As the Hedgehog pathway is upregulated in virtually all types of cancer cells, these findings substantially contribute to the explanation of uniform survivin expression in tumors as a potential target for the development of a more effective treatment of cancers through the inhibition of GLI2 to restrain survivin activity. PMID:26775700

  14. Outfoxing the Hedgehog

    ERIC Educational Resources Information Center

    Barbieri, Richard

    2011-01-01

    Jim Collins's "Good to Great" has attained near-scriptural status in organizations, including nonprofits, which Collins says constitute a third of his readers. The pivot point in "Good to Great" is the Hedgehog Concept. The "Hedgehog Concept" (HC), this author claims, is dangerous for schools because it distorts the nature of education. As Collins…

  15. A critical role for sonic hedgehog signaling in the early expansion of the developing brain.

    PubMed

    Britto, Joanne; Tannahill, David; Keynes, Roger

    2002-02-01

    The mechanisms that coordinate the three-dimensional shape of the vertebrate brain during development are largely unknown. We have found that sonic hedgehog (Shh) is crucial in driving the rapid, extensive expansion of the early vesicles of the developing midbrain and forebrain. Transient displacement of the notochord from the midbrain floor plate resulted in abnormal folding and overall collapse of the vesicles, accompanied by reduced cell proliferation and increased cell death in the midbrain. Simultaneously, expression of Shh decreased locally in the notochord and floor plate, whereas overt patterning and differentiation proceeded normally. Normal midbrain expansion was restored by implantation of Shh-secreting cells in a dose-dependent manner; conversely, expansion was retarded following antagonism of the Shh signaling pathway by cyclopamine. Our results indicate that Shh signaling from the ventral midline is essential for regulating brain morphogenesis during early development.

  16. A shared role for sonic hedgehog signalling in patterning chondrichthyan gill arch appendages and tetrapod limbs.

    PubMed

    Gillis, J Andrew; Hall, Brian K

    2016-04-15

    Chondrichthyans (sharks, skates, rays and holocephalans) possess paired appendages that project laterally from their gill arches, known as branchial rays. This led Carl Gegenbaur to propose that paired fins (and hence tetrapod limbs) originally evolved via transformation of gill arches. Tetrapod limbs are patterned by asonic hedgehog(Shh)-expressing signalling centre known as the zone of polarising activity, which establishes the anteroposterior axis of the limb bud and maintains proliferative expansion of limb endoskeletal progenitors. Here, we use loss-of-function, label-retention and fate-mapping approaches in the little skate to demonstrate that Shh secretion from a signalling centre in the developing gill arches establishes gill arch anteroposterior polarity and maintains the proliferative expansion of branchial ray endoskeletal progenitor cells. These findings highlight striking parallels in the axial patterning mechanisms employed by chondrichthyan branchial rays and paired fins/limbs, and provide mechanistic insight into the anatomical foundation of Gegenbaur's gill arch hypothesis. PMID:27095494

  17. Notch Activity Modulates the Responsiveness of Neural Progenitors to Sonic Hedgehog Signaling

    PubMed Central

    Kong, Jennifer H.; Yang, Linlin; Dessaud, Eric; Chuang, Katherine; Moore, Destaye M.; Rohatgi, Rajat; Briscoe, James; Novitch, Bennett G.

    2015-01-01

    Summary Throughout the developing nervous system, neural stem and progenitor cells give rise to diverse classes of neurons and glia in a spatially and temporally coordinated manner. In the ventral spinal cord, much of this diversity emerges through the morphogen actions of Sonic hedgehog (Shh). Interpretation of the Shh gradient depends on both the amount of ligand and duration of exposure, but the mechanisms permitting prolonged responses to Shh are not well understood. We demonstrate that Notch signaling plays an essential role in this process, enabling neural progenitors to attain sufficiently high levels of Shh pathway activity needed to direct the ventral-most cell fates. Notch activity regulates subcellular localization of the Shh receptor Patched1, gating the translocation of the key effector Smoothened to primary cilia and its downstream signaling activities. These data reveal an unexpected role for Notch shaping the interpretation of the Shh morphogen gradient and influencing cell fate determination. PMID:25936505

  18. Role of the ABC transporter Mdr49 in Hedgehog signaling and germ cell migration.

    PubMed

    Deshpande, Girish; Manry, Diane; Jourjine, Nicholas; Mogila, Vladic; Mozes, Henny; Bialistoky, Tzofia; Gerlitz, Offer; Schedl, Paul

    2016-06-15

    Coalescence of the embryonic gonad in Drosophila melanogaster requires directed migration of primordial germ cells (PGCs) towards somatic gonadal precursor cells (SGPs). It was recently proposed that the ATP-binding cassette (ABC) transporter Mdr49 functions in the embryonic mesoderm to facilitate the transmission of the PGC attractant from the SGPs; however, the precise molecular identity of the Mdr49-dependent guidance signal remained elusive. Employing the loss- and gain-of-function strategies, we show that Mdr49 is a component of the Hedgehog (hh) pathway and it potentiates the signaling activity. This function is direct because in Mdr49 mutant embryos the Hh ligand is inappropriately sequestered in the hh-expressing cells. Our data also suggest that the role of Mdr49 is to provide cholesterol for the correct processing of the Hh precursor protein. Supporting this conclusion, PGC migration defects in Mdr49 embryos are substantially ameliorated by a cholesterol-rich diet. PMID:27122170

  19. Vertebrate Hedgehog is secreted on two types of extracellular vesicles with different signaling properties

    PubMed Central

    Vyas, Neha; Walvekar, Ankita; Tate, Dhananjay; Lakshmanan, Vairavan; Bansal, Dhiru; Cicero, Alessandra Lo; Raposo, Graca; Palakodeti, Dasaradhi; Dhawan, Jyotsna

    2014-01-01

    Hedgehog (Hh) is a secreted morphogen that elicits differentiation and patterning in developing tissues. Multiple proposed mechanisms to regulate Hh dispersion includes lipoprotein particles and exosomes. Here we report that vertebrate Sonic Hedgehog (Shh) is secreted on two types of extracellular-vesicles/exosomes, from human cell lines and primary chick notochord cells. Although largely overlapping in size as estimated from electron micrographs, the two exosomal fractions exhibited distinct protein and RNA composition. We have probed the functional properties of these vesicles using cell-based assays of Hh-elicited gene expression. Our results suggest that while both Shh-containing exo-vesicular fractions can activate an ectopic Gli-luciferase construct, only exosomes co-expressing Integrins can activate endogenous Shh target genes HNF3β and Olig2 during the differentiation of mouse ES cells to ventral neuronal progenitors. Taken together, our results demonstrate that primary vertebrate cells secrete Shh in distinct vesicular forms, and support a model where packaging of Shh along with other signaling proteins such as Integrins on exosomes modulates target gene activation. The existence of distinct classes of Shh-containing exosomes also suggests a previously unappreciated complexity for fine-tuning of Shh-mediated gradients and pattern formation. PMID:25483805

  20. Hedgehog signalling controls zebrafish neural keel morphogenesis via its level-dependent effects on neurogenesis.

    PubMed

    Takamiya, Masanari; Campos-Ortega, Jose A

    2006-04-01

    We investigated the role of hedgehog (Hh) signalling on zebrafish neurulation, focusing on the intimate relationship between neurogenesis and morphogenesis during the neural keel stage. Through the analyses of Hh loss- and gain-of-function phenotypes, we found that Hh signalling controls the neural keel morphogenesis. To investigate underlying mechanisms, we examined cellular elongation polarity in the neural keel of Hh loss- and gain-of-function phenotypes and compared this with the deficient phenotype of a planar cell polarity (PCP) molecule, Trilobite/Strabismus. We found that Hh signalling controls cell elongation polarity of the neuroepithelium at least in part by means of PCP pathway; however, its effects are not strong enough per se to affect keel morphogenesis; instead Hh signalling mainly controls keel morphogenesis by means of affecting both medial and lateral neurogenesis. We devised a method for precise evaluation of neurogenesis in loss- and gain-of-Hh phenotypes that compensates for its delay caused by disturbed morphogenesis. We present a model that Hh signalling exerts level-dependent and binary-opposite effects on medial neurogenesis, whose modification to explain lateral neurogenesis reveals regional differences of underlying mechanisms between the two proneural domains. Such differences seem to be created in part by regional effector signalling; the effects of high Hh-signalling on medial neurogenesis can be reversed in accordance to medial Tri/Stbm level, in a polarity independent manner.

  1. Protein kinase A activation inhibits oncogenic Sonic hedgehog signalling and suppresses basal cell carcinoma of the skin.

    PubMed

    Makinodan, Eri; Marneros, Alexander G

    2012-11-01

    Basal cell carcinoma of the skin (BCC) is caused by constitutive activation of the Sonic hedgehog (Shh) pathway, mainly through mutations either in the Shh receptor Patched (PTCH) or in its co-receptor Smoothened (Smo). Inhibitors of this pathway that are currently in clinical trials inhibit Smo. However, mutations in Smo can result in resistance to these inhibitors. To target most BCCs and avoid acquired resistance because of Smo mutations, inhibiting the Shh-pathway downstream of Smo is critical. Attractive downstream targets would be at the level of Gli proteins, the transcriptional activators of this pathway in BCCs. Previously it has been shown that Gli1 and Gli2, when phosphorylated by protein kinase A (PKA), are targeted for proteosomal degradation. Here we show that PKA activation via the cAMP agonist forskolin is sufficient to completely abolish oncogenic Smo activity in vitro. In an inducible BCC mouse model due to a Smo mutation that confers resistance to current Smo inhibitors, topical forskolin treatment significantly reduced Gli1 mRNA levels and resulted in strongly suppressed BCC tumor growth. Our data show that forskolin inhibits the growth of even those BCCs that are resistant to Smo inhibitors and provide a proof-of-principle framework for the development of topically applied human skin-permeable novel pharmacologic inhibitors of oncogenic Shh-signaling through PKA activation. PMID:23163650

  2. Hedgehog signaling induces osteosarcoma development through Yap1 and H19 overexpression.

    PubMed

    Chan, L H; Wang, W; Yeung, W; Deng, Y; Yuan, P; Mak, K K

    2014-10-01

    Osteosarcoma is one of the most common bone tumors. However, the genetic basis for its pathogenesis remains elusive. Here, we investigated the roles of Hedgehog (Hh) signaling in osteosarcoma development. Genetically-engineered mice with ubiquitous upregulated Hh signaling specifically in mature osteoblasts develop focal bone overgrowth, which greatly resembles the early stage of osteosarcoma. However, these mice die within three months, which prohibits further analysis of tumor progression. We therefore generated a mouse model with partial upregulated Hh signaling in mature osteoblasts and crossed it into a p53 heterozygous background to potentiate tumor development. We found that these mutant mice developed malignant osteosarcoma with high penetrance. Isolated primary tumor cells were mainly osteoblastic and highly proliferative with many characteristics of human osteosarcomas. Allograft transplantation into immunocompromised mice displayed high tumorigenic potential. More importantly, both human and mouse tumor tissues express high level of yes-associated protein 1 (Yap1), a potent oncogene that is amplified in various cancers. We show that inhibition of Hh signaling reduces Yap1 expression and knockdown of Yap1 significantly inhibits tumor progression. Moreover, long non-coding RNA H19 is aberrantly expressed and induced by upregulated Hh signaling and Yap1 overexpression. Our results demonstrate that aberrant Hh signaling in mature osteoblasts is responsible for the pathogenesis of osteoblastic osteosarcoma through Yap1 and H19 overexpression.

  3. Ciliary IFT80 balances canonical versus non-canonical hedgehog signalling for osteoblast differentiation

    PubMed Central

    Yuan, Xue; Cao, Jay; He, Xiaoning; Serra, Rosa; Qu, Jun; Cao, Xu; Yang, Shuying

    2016-01-01

    Intraflagellar transport proteins (IFT) are required for hedgehog (Hh) signalling transduction that is essential for bone development, however, how IFT proteins regulate Hh signalling in osteoblasts (OBs) remains unclear. Here we show that deletion of ciliary IFT80 in OB precursor cells (OPC) in mice results in growth retardation and markedly decreased bone mass with impaired OB differentiation. Loss of IFT80 blocks canonical Hh–Gli signalling via disrupting Smo ciliary localization, but elevates non-canonical Hh–Gαi–RhoA–stress fibre signalling by increasing Smo and Gαi binding. Inhibition of RhoA and ROCK activity partially restores osteogenic differentiation of IFT80-deficient OPCs by inhibiting non-canonical Hh–RhoA–Cofilin/MLC2 signalling. Cytochalasin D, an actin destabilizer, dramatically restores OB differentiation of IFT80-deficient OPCs by disrupting actin stress fibres and promoting cilia formation and Hh–Gli signalling. These findings reveal that IFT80 is required for OB differentiation by balancing between canonical Hh–Gli and non-canonical Hh–Gαi–RhoA pathways and highlight IFT80 as a therapeutic target for craniofacial and skeletal abnormalities. PMID:26996322

  4. Ciliary IFT80 balances canonical versus non-canonical hedgehog signalling for osteoblast differentiation.

    PubMed

    Yuan, Xue; Cao, Jay; He, Xiaoning; Serra, Rosa; Qu, Jun; Cao, Xu; Yang, Shuying

    2016-03-21

    Intraflagellar transport proteins (IFT) are required for hedgehog (Hh) signalling transduction that is essential for bone development, however, how IFT proteins regulate Hh signalling in osteoblasts (OBs) remains unclear. Here we show that deletion of ciliary IFT80 in OB precursor cells (OPC) in mice results in growth retardation and markedly decreased bone mass with impaired OB differentiation. Loss of IFT80 blocks canonical Hh-Gli signalling via disrupting Smo ciliary localization, but elevates non-canonical Hh-Gαi-RhoA-stress fibre signalling by increasing Smo and Gαi binding. Inhibition of RhoA and ROCK activity partially restores osteogenic differentiation of IFT80-deficient OPCs by inhibiting non-canonical Hh-RhoA-Cofilin/MLC2 signalling. Cytochalasin D, an actin destabilizer, dramatically restores OB differentiation of IFT80-deficient OPCs by disrupting actin stress fibres and promoting cilia formation and Hh-Gli signalling. These findings reveal that IFT80 is required for OB differentiation by balancing between canonical Hh-Gli and non-canonical Hh-Gαi-RhoA pathways and highlight IFT80 as a therapeutic target for craniofacial and skeletal abnormalities.

  5. A Screen for Modifiers of Hedgehog Signaling in Drosophila melanogaster Identifies swm and mts

    PubMed Central

    Casso, David J.; Liu, Songmei; Iwaki, D. David; Ogden, Stacey K.; Kornberg, Thomas B.

    2008-01-01

    Signaling by Hedgehog (Hh) proteins shapes most tissues and organs in both vertebrates and invertebrates, and its misregulation has been implicated in many human diseases. Although components of the signaling pathway have been identified, key aspects of the signaling mechanism and downstream targets remain to be elucidated. We performed an enhancer/suppressor screen in Drosophila to identify novel components of the pathway and identified 26 autosomal regions that modify a phenotypic readout of Hh signaling. Three of the regions include genes that contribute constituents to the pathway—patched, engrailed, and hh. One of the other regions includes the gene microtubule star (mts) that encodes a subunit of protein phosphatase 2A. We show that mts is necessary for full activation of Hh signaling. A second region includes the gene second mitotic wave missing (swm). swm is recessive lethal and is predicted to encode an evolutionarily conserved protein with RNA binding and Zn+ finger domains. Characterization of newly isolated alleles indicates that swm is a negative regulator of Hh signaling and is essential for cell polarity. PMID:18245841

  6. Ciliary IFT80 balances canonical versus non-canonical hedgehog signalling for osteoblast differentiation.

    PubMed

    Yuan, Xue; Cao, Jay; He, Xiaoning; Serra, Rosa; Qu, Jun; Cao, Xu; Yang, Shuying

    2016-01-01

    Intraflagellar transport proteins (IFT) are required for hedgehog (Hh) signalling transduction that is essential for bone development, however, how IFT proteins regulate Hh signalling in osteoblasts (OBs) remains unclear. Here we show that deletion of ciliary IFT80 in OB precursor cells (OPC) in mice results in growth retardation and markedly decreased bone mass with impaired OB differentiation. Loss of IFT80 blocks canonical Hh-Gli signalling via disrupting Smo ciliary localization, but elevates non-canonical Hh-Gαi-RhoA-stress fibre signalling by increasing Smo and Gαi binding. Inhibition of RhoA and ROCK activity partially restores osteogenic differentiation of IFT80-deficient OPCs by inhibiting non-canonical Hh-RhoA-Cofilin/MLC2 signalling. Cytochalasin D, an actin destabilizer, dramatically restores OB differentiation of IFT80-deficient OPCs by disrupting actin stress fibres and promoting cilia formation and Hh-Gli signalling. These findings reveal that IFT80 is required for OB differentiation by balancing between canonical Hh-Gli and non-canonical Hh-Gαi-RhoA pathways and highlight IFT80 as a therapeutic target for craniofacial and skeletal abnormalities. PMID:26996322

  7. Hedgehog signaling activation induces stem cell proliferation and hormone release in the adult pituitary gland

    PubMed Central

    Pyczek, Joanna; Buslei, Rolf; Schult, David; Hölsken, Annett; Buchfelder, Michael; Heß, Ina; Hahn, Heidi; Uhmann, Anja

    2016-01-01

    Hedgehog (HH) signaling is known to be essential during the embryonal development of the pituitary gland but the knowledge about its role in the adult pituitary and in associated tumors is sparse. In this report we investigated the effect of excess Hh signaling activation in murine pituitary explants and analyzed the HH signaling status of human adenopituitary lobes and a large cohort of pituitary adenomas. Our data show that excess Hh signaling led to increased proliferation of Sox2+ and Sox9+ adult pituitary stem cells and to elevated expression levels of adrenocorticotropic hormone (Acth), growth hormone (Gh) and prolactin (Prl) in the adult gland. Inhibition of the pathway by cyclopamine reversed these effects indicating that active Hh signaling positively regulates proliferative processes of adult pituitary stem cells and hormone production in the anterior pituitary. Since hormone producing cells of the adenohypophysis as well as ACTH-, GH- and PRL-immunopositive adenomas express SHH and its target GLI1, we furthermore propose that excess HH signaling is involved in the development/maintenance of hormone-producing pituitary adenomas. These findings advance the understanding of physiological hormone regulation and may open new treatment options for pituitary tumors. PMID:27109116

  8. Basal cell carcinoma and the carcinogenic role of aberrant Hedgehog signaling.

    PubMed

    Saran, Anna

    2010-06-01

    Basal cell carcinoma (BCC) is the most frequent cancer in the white population and its incidence appears to be increasing worldwide. While the majority of BCCs arise sporadically, many cases are attributable to basal cell nevus syndrome, or Gorlin syndrome, an autosomal dominantly inherited disorder characterized by the occurrence of multiple BCCs and by extracutaneous tumors. Genetic studies on patients with basal cell nevus syndrome indicate deregulation of the Hedgehog (Hh) pathway in epidermal keratinocytes as the primary event in the pathogenesis of BCC. This article summarizes the recent progress in understanding Hh-dependent BCC tumorigenesis, as well as evidence for deregulation of other molecular pathways, primarily the Wnt developmental pathway. Understanding the molecular genetics of BCC development has provided new opportunities for molecular therapy of this cancer by targeting Hh and other signaling pathways. PMID:20528237

  9. Structural insights into human Kif7, a kinesin involved in Hedgehog signalling

    PubMed Central

    Klejnot, Marta; Kozielski, Frank

    2012-01-01

    Kif7, a member of the kinesin 4 superfamily, is implicated in a variety of diseases including Joubert, hydrolethalus and acrocallosal syndromes. It is also involved in primary cilium formation and the Hedgehog signalling pathway and may play a role in cancer. Its activity is crucial for embryonic development. Kif7 and Kif27, a closely related kinesin in the same subfamily, are orthologues of the Drosophila melano­gaster kinesin-like protein Costal-2 (Cos2). In vertebrates, they work together to fulfil the role of the single Cos2 gene in Drosophila. Here, the high-resolution structure of the human Kif7 motor domain is reported and is compared with that of conventional kinesin, the founding member of the kinesin superfamily. These data are a first step towards structural characterization of a kinesin-4 family member and of this interesting molecular motor of medical significance. PMID:22281744

  10. A Group of ent-Kaurane Diterpenoids Inhibit Hedgehog Signaling and Induce Cilia Elongation

    PubMed Central

    Jiang, Shiyou; Du, Jiacheng; Kong, Qinghua; Li, Chaocui; Li, Yan; Sun, Handong; Pu, Jianxin; Mao, Bingyu

    2015-01-01

    The Hedgehog (Hh) signaling pathway plays important roles in the tumorigenesis of multiple cancers and is a key target for drug discovery. In a screen of natural products extracted from Chinese herbs, we identified eight ent-Kaurane diterpenoids and two triterpene dilactones as novel Hh pathway antagonists. Epistatic analyses suggest that these compounds likely act at the level or downstream of Smoothened (Smo) and upstream of Suppressor of Fused (Sufu). The ent-Kauranoid-treated cells showed elongated cilia, suppressed Smo trafficking to cilia, and mitotic defects, while the triterpene dilactones had no effect on the cilia and ciliary Smo. These ent-Kaurane diterpenoids provide new prototypes of Hh inhibitors, and are valuable probes for deciphering the mechanisms of Smo ciliary transport and ciliogenesis. PMID:26439749

  11. Hedgehog signaling pathway regulated the target genes for adipogenesis in silkworm Bombyx mori.

    PubMed

    Liang, Shuang; Chen, Rui-Ting; Zhang, Deng-Pan; Xin, Hu-Hu; Lu, Yan; Wang, Mei-Xian; Miao, Yun-Gen

    2015-10-01

    Hedgehog (Hh) signals regulate invertebrate and vertebrate development, yet the role of the pathway in adipose development remains poorly understood. In this report, we found that Hh pathway components are expressed in the fat body of silkworm larvae. Functional analysis of these components in a BmN cell line model revealed that activation of the Hh gene stimulated transcription of Hh pathway components, but inhibited the expression of the adipose marker gene AP2. Conversely, specific RNA interference-mediated knockdown of Hh resulted in increased AP2 expression. This further showed the regulation of Hh signal on the adipose marker gene. In silkworm larval models, enhanced adipocyte differentiation and an increase in adipocyte cell size were observed in silkworms that had been treated with a specific Hh signaling pathway antagonist, cyclopamine. The fat-body-specific Hh blockade tests were consistent with Hh signaling inhibiting silkworm adipogenesis. Our results indicate that the role of Hh signaling in inhibiting fat formation is conserved in vertebrates and invertebrates.

  12. MicroRNAs in liver fibrosis: Focusing on the interaction with hedgehog signaling

    PubMed Central

    Hyun, Jeongeun; Jung, Youngmi

    2016-01-01

    Liver fibrosis is a repair process in response to damage in the liver; however, severe and chronic injury promotes the accumulation of fibrous matrix, destroying the normal functions and architecture of liver. Hepatic stellate cells (HSCs) are quiescent in normal livers, but in damaged livers, they transdifferentiate into myofibroblastic HSCs, which produce extracellular matrix proteins. Hedgehog (Hh) signaling orchestrates tissue reconstruction in damaged livers and contributes to liver fibrogenesis by regulating HSC activation. MicroRNAs (miRNAs), endogenous small non-coding RNAs interfering with RNA post-transcriptionally, regulate various cellular processes in healthy organisms. The dysregulation of miRNAs is closely associated with diseases, including liver diseases. Thus, miRNAs are good targets in the diagnosis and treatment of various diseases, including liver fibrosis; however, the regulatory mechanisms of miRNAs that interact with Hh signaling in liver fibrosis remain unclear. We review growing evidence showing the association of miRNAs with Hh signaling. Recent studies suggest that Hh-regulating miRNAs induce inactivation of HSCs, leading to decreased hepatic fibrosis. Although miRNA-delivery systems and further knowledge of interacting miRNAs with Hh signaling need to be improved for the clinical usage of miRNAs, recent findings indicate that the miRNAs regulating Hh signaling are promising therapeutic agents for treating liver fibrosis. PMID:27547008

  13. Sonic hedgehog signaling regulates mode of cell division of early cerebral cortex progenitors and increases astrogliogenesis

    PubMed Central

    Araújo, Geissy L. L.; Araújo, Jessica A. M.; Schroeder, Timm; Tort, Adriano B. L.; Costa, Marcos R.

    2014-01-01

    The morphogen Sonic Hedgehog (SHH) plays a critical role in the development of different tissues. In the central nervous system, SHH is well known to contribute to the patterning of the spinal cord and separation of the brain hemispheres. In addition, it has recently been shown that SHH signaling also contributes to the patterning of the telencephalon and establishment of adult neurogenic niches. In this work, we investigated whether SHH signaling influences the behavior of neural progenitors isolated from the dorsal telencephalon, which generate excitatory neurons and macroglial cells in vitro. We observed that SHH increases proliferation of cortical progenitors and generation of astrocytes, whereas blocking SHH signaling with cyclopamine has opposite effects. In both cases, generation of neurons did not seem to be affected. However, cell survival was broadly affected by blockade of SHH signaling. SHH effects were related to three different cell phenomena: mode of cell division, cell cycle length and cell growth. Together, our data in vitro demonstrate that SHH signaling controls cell behaviors that are important for proliferation of cerebral cortex progenitors, as well as differentiation and survival of neurons and astroglial cells. PMID:24653675

  14. MicroRNAs in liver fibrosis: Focusing on the interaction with hedgehog signaling.

    PubMed

    Hyun, Jeongeun; Jung, Youngmi

    2016-08-01

    Liver fibrosis is a repair process in response to damage in the liver; however, severe and chronic injury promotes the accumulation of fibrous matrix, destroying the normal functions and architecture of liver. Hepatic stellate cells (HSCs) are quiescent in normal livers, but in damaged livers, they transdifferentiate into myofibroblastic HSCs, which produce extracellular matrix proteins. Hedgehog (Hh) signaling orchestrates tissue reconstruction in damaged livers and contributes to liver fibrogenesis by regulating HSC activation. MicroRNAs (miRNAs), endogenous small non-coding RNAs interfering with RNA post-transcriptionally, regulate various cellular processes in healthy organisms. The dysregulation of miRNAs is closely associated with diseases, including liver diseases. Thus, miRNAs are good targets in the diagnosis and treatment of various diseases, including liver fibrosis; however, the regulatory mechanisms of miRNAs that interact with Hh signaling in liver fibrosis remain unclear. We review growing evidence showing the association of miRNAs with Hh signaling. Recent studies suggest that Hh-regulating miRNAs induce inactivation of HSCs, leading to decreased hepatic fibrosis. Although miRNA-delivery systems and further knowledge of interacting miRNAs with Hh signaling need to be improved for the clinical usage of miRNAs, recent findings indicate that the miRNAs regulating Hh signaling are promising therapeutic agents for treating liver fibrosis. PMID:27547008

  15. SCF (Fbxl17) ubiquitylation of Sufu regulates Hedgehog signaling and medulloblastoma development.

    PubMed

    Raducu, Madalina; Fung, Ella; Serres, Sébastien; Infante, Paola; Barberis, Alessandro; Fischer, Roman; Bristow, Claire; Thézénas, Marie-Laëtitia; Finta, Csaba; Christianson, John C; Buffa, Francesca M; Kessler, Benedikt M; Sibson, Nicola R; Di Marcotullio, Lucia; Toftgård, Rune; D'Angiolella, Vincenzo

    2016-07-01

    Skp1-Cul1-F-box protein (SCF) ubiquitin ligases direct cell survival decisions by controlling protein ubiquitylation and degradation. Sufu (Suppressor of fused) is a central regulator of Hh (Hedgehog) signaling and acts as a tumor suppressor by maintaining the Gli (Glioma-associated oncogene homolog) transcription factors inactive. Although Sufu has a pivotal role in Hh signaling, the players involved in controlling Sufu levels and their role in tumor growth are unknown. Here, we show that Fbxl17 (F-box and leucine-rich repeat protein 17) targets Sufu for proteolysis in the nucleus. The ubiquitylation of Sufu, mediated by Fbxl17, allows the release of Gli1 from Sufu for proper Hh signal transduction. Depletion of Fbxl17 leads to defective Hh signaling associated with an impaired cancer cell proliferation and medulloblastoma tumor growth. Furthermore, we identify a mutation in Sufu, occurring in medulloblastoma of patients with Gorlin syndrome, which increases Sufu turnover through Fbxl17-mediated polyubiquitylation and leads to a sustained Hh signaling activation. In summary, our findings reveal Fbxl17 as a novel regulator of Hh pathway and highlight the perturbation of the Fbxl17-Sufu axis in the pathogenesis of medulloblastoma. PMID:27234298

  16. miR-219 regulates neural progenitors by dampening apical Par protein-dependent Hedgehog signaling.

    PubMed

    Hudish, Laura I; Galati, Domenico F; Ravanelli, Andrew M; Pearson, Chad G; Huang, Peng; Appel, Bruce

    2016-07-01

    The transition of dividing neuroepithelial progenitors to differentiated neurons and glia is essential for the formation of a functional nervous system. Sonic hedgehog (Shh) is a mitogen for spinal cord progenitors, but how cells become insensitive to the proliferative effects of Shh is not well understood. Because Shh reception occurs at primary cilia, which are positioned within the apical membrane of neuroepithelial progenitors, we hypothesized that loss of apical characteristics reduces the Shh signaling response, causing cell cycle exit and differentiation. We tested this hypothesis using genetic and pharmacological manipulation, gene expression analysis and time-lapse imaging of zebrafish embryos. Blocking the function of miR-219, a microRNA that downregulates apical Par polarity proteins and promotes progenitor differentiation, elevated Shh signaling. Inhibition of Shh signaling reversed the effects of miR-219 depletion and forced expression of Shh phenocopied miR-219 deficiency. Time-lapse imaging revealed that knockdown of miR-219 function accelerates the growth of primary cilia, revealing a possible mechanistic link between miR-219-mediated regulation of apical Par proteins and Shh signaling. Thus, miR-219 appears to decrease progenitor cell sensitivity to Shh signaling, thereby driving these cells towards differentiation. PMID:27226318

  17. Hedgehog signaling induced by breast cancer cells promotes osteoclastogenesis and osteolysis.

    PubMed

    Das, Shamik; Samant, Rajeev S; Shevde, Lalita A

    2011-03-18

    Bone integrity is maintained by a dynamic equilibrium between the activities of bone-forming osteoblasts and bone-resorbing osteoclasts. Osteolytic lesions are a painful consequence of metastasis of breast cancer cells to bone in an overwhelming majority of breast cancer patients. Factors secreted by breast cancer cells propel a cascade of events that trigger osteoclastogenesis and elevated bone resorption. In the present study, we show that the Hedgehog (Hh) ligands secreted by breast cancer cells promote osteoclast differentiation and potentiate the activity of mature osteoclasts. Paracrine Hh signaling induced by breast cancer cells mediates a detrimental chain of events by the up-regulation of osteopontin (OPN), which in turn enhances osteoclastic activity by up-regulating cathepsin K and MMP9. Hh signaling is essential for osteoclasts because blocking the Hh pathway using the pharmacological Hh inhibitor, cyclopamine, results in an overall decrease in osteoclastogenesis and resorptive activity. Our studies suggest that inhibiting Hh signaling interferes with the ability of pre-osteoclasts to respond to the stimulatory effects of the breast cancer cells, indicating that Hh signaling is vital to osteoclast activity. PMID:21169638

  18. Aberrant activation of Sonic hedgehog signaling in chronic cholecystitis and gallbladder carcinoma.

    PubMed

    Xie, Fang; Xu, Xiaoping; Xu, Angao; Liu, Cuiping; Liang, Fenfen; Xue, Minmin; Bai, Lan

    2014-03-01

    Sonic hedgehog (Shh) signaling has been extensively studied and is implicated in various inflammatory diseases and malignant tumors. We summarized the clinicopathological features and performed immunohistochemistry assays to examine expression of Shh signaling proteins in 10 normal mucosa, 32 gallbladder carcinoma (GBC), and 95 chronic cholecystitis (CC) specimens. The CC specimens were classified into three groups according to degree of inflammation. Compared with normal mucosa, CC, and GBC specimens exhibited increased expression of Shh. The immunoreactive score of Shh in the GBC group was higher than that in the mild to moderate CC groups but lower than that in the severe CC group (P < .05). Expression of Patched (Ptch) and Gli1 gradually increased from non-malignant cholecystitis to malignant tumors. Compared with CC specimens, GBC specimens showed higher cytoplasmic and membranous expression for Ptch (P < .05). Gli1 staining showed cytoplasmic expression of Gli1 in both CC (60% for mild, 77% for moderate, and 84% for severe) and GBC specimens (97%). Nuclear expression of Gli1 was detected in 16% of severe CC specimens with moderate to poor atypical hyperplasia, and in 62.5% of GBC specimens. Shh expression strongly correlated with expression of Ptch and Gli1. Furthermore, patients with strongly positive Gli1 staining had significantly lower survival rates than those with weakly positive staining. Our data indicate that the Shh signaling pathway is aberrantly activated in CC and GBC, and altered Shh signaling may be involved in the course of development from CC to gallbladder carcinogenesis.

  19. IFT80 is essential for chondrocyte differentiation by regulating hedgehog and Wnt signaling pathways

    PubMed Central

    Wang, Changdong; Yuan, Xue; Yang, Shuying

    2013-01-01

    Partial mutation of intraflagellar transport 80 (IFT80) in humans causes Jeune asphyxiating thoracic dystrophy (JATD) and short-rib polydactyly (SRP) syndrome type III. These diseases are autosomal recessive chondrodysplasias that share clinical similarities, including shortened long bones and constricted thoracic cage. However, the role and mechanism of IFT80 in the regulation of chondrocyte differentiation and function remain largely unknown. We hypothesize that IFT80 is required for the formation and function of cilia and plays a critical role in chondrogenic differentiation by regulating Hedgehog (Hh) and Wingless (Wnt) signaling pathways. To test this hypothesis, we first analyzed the IFT80 expression pattern and found that IFT80 was predominantly expressed in growth plate chondrocytes and during chondrogenic differentiation. Silencing IFT80 impaired cilia formation and chondrogenic differentiation in mouse bone marrow derived stromal cells (BMSCs), and decreased the expression of chondrocyte marker genes—collagen II and aggrecan. Additionally, silencing IFT80 down-regulated Hh signaling activity whereas up-regulated Wnt signaling activity. The overexpression of Gli2 in IFT80-silenced cells promoted chondrogenesis and recovered the chondrogenic deficiency from IFT80 silencing. Overall, our results demonstrate that IFT80 is essential for chondrocyte differentiation by regulating the Hh and Wnt signaling pathways. PMID:23333501

  20. Contribution of hedgehog signaling to the establishment of left-right asymmetry in the sea urchin.

    PubMed

    Warner, Jacob F; Miranda, Esther L; McClay, David R

    2016-03-15

    Most bilaterians exhibit a left-right asymmetric distribution of their internal organs. The sea urchin larva is notable in this regard since most adult structures are generated from left sided embryonic structures. The gene regulatory network governing this larval asymmetry is still a work in progress but involves several conserved signaling pathways including Nodal, and BMP. Here we provide a comprehensive analysis of Hedgehog signaling and it's contribution to left-right asymmetry. We report that Hh signaling plays a conserved role to regulate late asymmetric expression of Nodal and that this regulation occurs after Nodal breaks left-right symmetry in the mesoderm. Thus, while Hh functions to maintain late Nodal expression, the molecular asymmetry of the future coelomic pouches is locked in. Furthermore we report that cilia play a role only insofar as to transduce Hh signaling and do not have an independent effect on the asymmetry of the mesoderm. From this, we are able to construct a more complete regulatory network governing the establishment of left-right asymmetry in the sea urchin.

  1. Hedgehog signaling enables nutrition-responsive inhibition of an alternative morph in a polyphenic beetle

    PubMed Central

    Kijimoto, Teiya; Moczek, Armin P.

    2016-01-01

    The recruitment of modular developmental genetic components into new developmental contexts has been proposed as a central mechanism enabling the origin of novel traits and trait functions without necessitating the origin of novel pathways. Here, we investigate the function of the hedgehog (Hh) signaling pathway, a highly conserved pathway best understood for its role in patterning anterior/posterior (A/P) polarity of diverse traits, in the developmental evolution of beetle horns, an evolutionary novelty, and horn polyphenisms, a highly derived form of environment-responsive trait induction. We show that interactions among pathway members are conserved during development of Onthophagus horned beetles and have retained the ability to regulate A/P polarity in traditional appendages, such as legs. At the same time, the Hh signaling pathway has acquired a novel and highly unusual role in the nutrition-dependent regulation of horn polyphenisms by actively suppressing horn formation in low-nutrition males. Down-regulation of Hh signaling lifts this inhibition and returns a highly derived sigmoid horn body size allometry to its presumed ancestral, linear state. Our results suggest that recruitment of the Hh signaling pathway may have been a key step in the evolution of trait thresholds, such as those involved in horn polyphenisms and the corresponding origin of alternative phenotypes and complex allometries. PMID:27162357

  2. Distinct spatiotemporal roles of hedgehog signalling during chick and mouse cranial base and axial skeleton development

    PubMed Central

    Balczerski, B.; Zakaria, S.; Tucker, A. S.; Borycki, A.G.; Koyama, E.; Pacifici, M.; Francis-West, P.

    2012-01-01

    The cranial base exerts a supportive role for the brain and includes the occipital, sphenoid and ethmoid bones that arise from cartilaginous precursors in the early embryo. As the occipital bone and the posterior part of the sphenoid are mesoderm derivatives that arise in close proximity to the notochord and floor plate, it has been assumed that their development, like the axial skeleton, is dependent on Sonic hedgehog (Shh) and modulation of bone morphogenetic protein (Bmp) signalling. Here we examined the development of the cranial base in chick and mouse embryos to compare the molecular signals that are required for chondrogenic induction in the trunk and head. We found that Shh signalling is required but the molecular network controlling cranial base development is distinct from that in the trunk. In the absence of Shh, the presumptive cranial base did not undergo chondrogenic commitment as determined by the loss of Sox9 expression and there was a decrease in cell survival. In contrast, induction of the otic capsule occurred normally demonstrating that induction of the cranial base is uncoupled from formation of the sensory capsules. Lastly, we found that the early cranial mesoderm is refractory to Shh signalling, likely accounting for why development of the cranial base occurs after the axial skeleton. Our data reveal that cranial and axial skeletal induction is controlled by conserved, yet spatiotemporally distinct mechanisms that co-ordinate development of the cranial base with that of the cranial musculature and the pharyngeal arches. PMID:23009899

  3. Nerves Control Redox Levels in Mature Tissues Through Schwann Cells and Hedgehog Signaling

    PubMed Central

    Meda, Francesca; Gauron, Carole; Rampon, Christine; Teillon, Jérémie; Volovitch, Michel

    2016-01-01

    Abstract Aims: Recent advances in redox biology have emphasized the role of hydrogen peroxide (H2O2) in the modulation of signaling pathways and revealed that H2O2 plays a role in cellular remodeling in adults. Thus, an understanding of the mechanisms that control H2O2 levels in mature tissue would be of great interest. Results: We used a denervation strategy to demonstrate that sensory neurons are responsible for controlling H2O2 levels under normal conditions and after being lesioned. Moreover, we demonstrate that severed nerves respond to appendage amputation via the induction of Hedgehog signaling and that this signaling is responsible for H2O2 production in the wounded epidermis. Finally, we show that H2O2 and nerve growth are regulated via reciprocal action in adults. Innovation and Conclusion: These data support a new paradigm for the regulation of tissue homeostasis: H2O2 attracts nerves and nerves control H2O2 levels in a positive feedback loop. This finding suggests that the peripheral nerve redox environment could be a target for manipulating cell plasticity in adults. Antioxid. Redox Signal. 24, 299–311. PMID:26442784

  4. Curcumin regulates cell fate and metabolism by inhibiting hedgehog signaling in hepatic stellate cells.

    PubMed

    Lian, Naqi; Jiang, Yuanyuan; Zhang, Feng; Jin, Huanhuan; Lu, Chunfeng; Wu, Xiafei; Lu, Yin; Zheng, Shizhong

    2015-07-01

    Accumulating evidence indicates that Hedgehog (Hh) signaling becomes activated in chronic liver injury and plays a role in the pathogenesis of hepatic fibrosis. Hepatic stellate cells (HSCs) are Hh-responsive cells and activation of the Hh pathway promotes transdifferentiation of HSCs into myofibroblasts. Targeting Hh signaling may be a novel therapeutic strategy for treatment of liver fibrosis. We previously reported that curcumin has potent antifibrotic effects in vivo and in vitro, but the underlying mechanisms are not fully elucidated. This study shows that curcumin downregulated Patched and Smoothened, two key elements in Hh signaling, but restored Hhip expression in rat liver with carbon tetrachloride-induced fibrosis and in cultured HSCs. Curcumin also halted the nuclear translocation, DNA binding, and transcription activity of Gli1. Moreover, the Hh signaling inhibitor cyclopamine, like curcumin, arrested the cell cycle, induced mitochondrial apoptosis, reduced fibrotic gene expression, restored lipid accumulation, and inhibited invasion and migration in HSCs. However, curcumin's effects on cell fate and fibrogenic properties of HSCs were abolished by the Hh pathway agonist SAG. Furthermore, curcumin and cyclopamine decreased intracellular levels of adenosine triphosphate and lactate, and inhibited the expression and/or function of several key molecules controlling glycolysis. However, SAG abrogated the curcumin effects on these parameters of glycolysis. Animal data also showed that curcumin downregulated glycolysis-regulatory proteins in rat fibrotic liver. These aggregated data therefore indicate that curcumin modulated cell fate and metabolism by disrupting the Hh pathway in HSCs, providing novel molecular insights into curcumin reduction of HSC activation.

  5. Contribution of hedgehog signaling to the establishment of left-right asymmetry in the sea urchin.

    PubMed

    Warner, Jacob F; Miranda, Esther L; McClay, David R

    2016-03-15

    Most bilaterians exhibit a left-right asymmetric distribution of their internal organs. The sea urchin larva is notable in this regard since most adult structures are generated from left sided embryonic structures. The gene regulatory network governing this larval asymmetry is still a work in progress but involves several conserved signaling pathways including Nodal, and BMP. Here we provide a comprehensive analysis of Hedgehog signaling and it's contribution to left-right asymmetry. We report that Hh signaling plays a conserved role to regulate late asymmetric expression of Nodal and that this regulation occurs after Nodal breaks left-right symmetry in the mesoderm. Thus, while Hh functions to maintain late Nodal expression, the molecular asymmetry of the future coelomic pouches is locked in. Furthermore we report that cilia play a role only insofar as to transduce Hh signaling and do not have an independent effect on the asymmetry of the mesoderm. From this, we are able to construct a more complete regulatory network governing the establishment of left-right asymmetry in the sea urchin. PMID:26872875

  6. A mouse model for Meckel syndrome reveals Mks1 is required for ciliogenesis and Hedgehog signaling

    PubMed Central

    Weatherbee, Scott D.; Niswander, Lee A.; Anderson, Kathryn V.

    2009-01-01

    Meckel syndrome (MKS) is a rare autosomal recessive disease causing perinatal lethality associated with a complex syndrome that includes occipital meningoencephalocele, hepatic biliary ductal plate malformation, postaxial polydactyly and polycystic kidneys. The gene mutated in type 1 MKS encodes a protein associated with the base of the cilium in vertebrates and nematodes. However, shRNA knockdown studies in cell culture have reported conflicting results on the role of Mks1 in ciliogenesis. Here we show that loss of function of mouse Mks1 results in an accurate model of human MKS, with structural abnormalities in the neural tube, biliary duct, limb patterning, bone development and the kidney that mirror the human syndrome. In contrast to cell culture studies, loss of Mks1 in vivo does not interfere with apical localization of epithelial basal bodies but rather leads to defective cilia formation in most, but not all, tissues. Analysis of patterning in the neural tube and the limb demonstrates altered Hedgehog (Hh) pathway signaling underlies some MKS defects, although both tissues show an expansion of the domain of response to Shh signaling, unlike the phenotypes seen in other mutants with cilia loss. Other defects in the skull, lung, rib cage and long bones are likely to be the result of the disruption of Hh signaling, and the basis of defects in the liver and kidney require further analysis. Thus the disruption of Hh signaling can explain many, but not all, of the defects caused by loss of Mks1. PMID:19776033

  7. Structure and function of the Smoothened extracellular domain in vertebrate Hedgehog signaling

    PubMed Central

    Nachtergaele, Sigrid; Whalen, Daniel M; Mydock, Laurel K; Zhao, Zhonghua; Malinauskas, Tomas; Krishnan, Kathiresan; Ingham, Philip W; Covey, Douglas F; Siebold, Christian; Rohatgi, Rajat

    2013-01-01

    The Hedgehog (Hh) signal is transduced across the membrane by the heptahelical protein Smoothened (Smo), a developmental regulator, oncoprotein and drug target in oncology. We present the 2.3 Å crystal structure of the extracellular cysteine rich domain (CRD) of vertebrate Smo and show that it binds to oxysterols, endogenous lipids that activate Hh signaling. The oxysterol-binding groove in the Smo CRD is analogous to that used by Frizzled 8 to bind to the palmitoleyl group of Wnt ligands and to similar pockets used by other Frizzled-like CRDs to bind hydrophobic ligands. The CRD is required for signaling in response to native Hh ligands, showing that it is an important regulatory module for Smo activation. Indeed, targeting of the Smo CRD by oxysterol-inspired small molecules can block signaling by all known classes of Hh activators and by clinically relevant Smo mutants. DOI: http://dx.doi.org/10.7554/eLife.01340.001 PMID:24171105

  8. Hedgehog signaling is a potent regulator of liver lipid metabolism and reveals a GLI-code associated with steatosis.

    PubMed

    Matz-Soja, Madlen; Rennert, Christiane; Schönefeld, Kristin; Aleithe, Susanne; Boettger, Jan; Schmidt-Heck, Wolfgang; Weiss, Thomas S; Hovhannisyan, Amalya; Zellmer, Sebastian; Klöting, Nora; Schulz, Angela; Kratzsch, Jürgen; Guthke, Reinhardt; Gebhardt, Rolf

    2016-01-01

    Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in industrialized countries and is increasing in prevalence. The pathomechanisms, however, are poorly understood. This study assessed the unexpected role of the Hedgehog pathway in adult liver lipid metabolism. Using transgenic mice with conditional hepatocyte-specific deletion of Smoothened in adult mice, we showed that hepatocellular inhibition of Hedgehog signaling leads to steatosis by altering the abundance of the transcription factors GLI1 and GLI3. This steatotic 'Gli-code' caused the modulation of a complex network of lipogenic transcription factors and enzymes, including SREBP1 and PNPLA3, as demonstrated by microarray analysis and siRNA experiments and could be confirmed in other steatotic mouse models as well as in steatotic human livers. Conversely, activation of the Hedgehog pathway reversed the "Gli-code" and mitigated hepatic steatosis. Collectively, our results reveal that dysfunctions in the Hedgehog pathway play an important role in hepatic steatosis and beyond. PMID:27185526

  9. Hedgehog signaling is a potent regulator of liver lipid metabolism and reveals a GLI-code associated with steatosis

    PubMed Central

    Matz-Soja, Madlen; Rennert, Christiane; Schönefeld, Kristin; Aleithe, Susanne; Boettger, Jan; Schmidt-Heck, Wolfgang; Weiss, Thomas S; Hovhannisyan, Amalya; Zellmer, Sebastian; Klöting, Nora; Schulz, Angela; Kratzsch, Jürgen; Guthke, Reinhardt; Gebhardt, Rolf

    2016-01-01

    Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in industrialized countries and is increasing in prevalence. The pathomechanisms, however, are poorly understood. This study assessed the unexpected role of the Hedgehog pathway in adult liver lipid metabolism. Using transgenic mice with conditional hepatocyte-specific deletion of Smoothened in adult mice, we showed that hepatocellular inhibition of Hedgehog signaling leads to steatosis by altering the abundance of the transcription factors GLI1 and GLI3. This steatotic 'Gli-code' caused the modulation of a complex network of lipogenic transcription factors and enzymes, including SREBP1 and PNPLA3, as demonstrated by microarray analysis and siRNA experiments and could be confirmed in other steatotic mouse models as well as in steatotic human livers. Conversely, activation of the Hedgehog pathway reversed the "Gli-code" and mitigated hepatic steatosis. Collectively, our results reveal that dysfunctions in the Hedgehog pathway play an important role in hepatic steatosis and beyond. DOI: http://dx.doi.org/10.7554/eLife.13308.001 PMID:27185526

  10. Association between FOXM1 and hedgehog signaling pathway in human cervical carcinoma by tissue microarray analysis

    PubMed Central

    Chen, Hong; Wang, Jingjing; Yang, Hong; Chen, Dan; Li, Panpan

    2016-01-01

    Forkhead box M1 (FOXM1) and hedgehog (Hh) signaling pathway are implicated in the formation and development of human tumors, including cervical cancer. Previous studies have indicated that FOXM1 may be a downstream target gene of the Hh signaling pathway, but their association in cervical cancer is largely unknown. In the present study, the expression of FOXM1 and Hh signaling molecules was evaluated by immunohistochemical analysis in a tissue microarray that contained 70 cervical cancer tissues and 10 normal cervical tissues. In addition, the association of these molecules with clinicopathological parameters, and the association between FOXM1 and various molecules involved in the Hh signaling pathway was investigated. The results indicated that FOXM1 and Hh signaling molecules were overexpressed in cervical cancer tissues. The protein expression levels of FOXM1, glioma-associated oncogene 1 (GLI1) and smoothened (SMO) correlated with the clinical stage of the tumors, while the protein expression levels of Sonic Hh (SHh), patched 1 (PTCH1) and GLI1 correlated with the pathological grade of the tumors. The expression levels of GLI1 were lower in tissues without lymph node metastasis than in tissues with lymph node metastasis. In addition, FOXM1 expression correlated with GLI1, SHh and PTCH1 expression in cancer tissues. These findings confirmed the participation of FOXM1 and the Hh signaling pathway in cervical cancer. Furthermore, the finding that FOXM1 may be a downstream target gene of the Hh signaling pathway in cervical cancer provides a potential novel diagnostic and therapeutic target for cervical cancer.

  11. Association between FOXM1 and hedgehog signaling pathway in human cervical carcinoma by tissue microarray analysis

    PubMed Central

    Chen, Hong; Wang, Jingjing; Yang, Hong; Chen, Dan; Li, Panpan

    2016-01-01

    Forkhead box M1 (FOXM1) and hedgehog (Hh) signaling pathway are implicated in the formation and development of human tumors, including cervical cancer. Previous studies have indicated that FOXM1 may be a downstream target gene of the Hh signaling pathway, but their association in cervical cancer is largely unknown. In the present study, the expression of FOXM1 and Hh signaling molecules was evaluated by immunohistochemical analysis in a tissue microarray that contained 70 cervical cancer tissues and 10 normal cervical tissues. In addition, the association of these molecules with clinicopathological parameters, and the association between FOXM1 and various molecules involved in the Hh signaling pathway was investigated. The results indicated that FOXM1 and Hh signaling molecules were overexpressed in cervical cancer tissues. The protein expression levels of FOXM1, glioma-associated oncogene 1 (GLI1) and smoothened (SMO) correlated with the clinical stage of the tumors, while the protein expression levels of Sonic Hh (SHh), patched 1 (PTCH1) and GLI1 correlated with the pathological grade of the tumors. The expression levels of GLI1 were lower in tissues without lymph node metastasis than in tissues with lymph node metastasis. In addition, FOXM1 expression correlated with GLI1, SHh and PTCH1 expression in cancer tissues. These findings confirmed the participation of FOXM1 and the Hh signaling pathway in cervical cancer. Furthermore, the finding that FOXM1 may be a downstream target gene of the Hh signaling pathway in cervical cancer provides a potential novel diagnostic and therapeutic target for cervical cancer. PMID:27698840

  12. Hippi is essential for node cilia assembly and Sonic hedgehog signaling

    PubMed Central

    Houde, Caroline; Dickinson, Robin J.; Houtzager, Vicky M.; Cullum, Rebecca; Montpetit, Rachel; Metzler, Martina; Simpson, Elizabeth M.; Roy, Sophie; Hayden, Michael R.; Hoodless, Pamela A.; Nicholson, Donald W.

    2016-01-01

    Hippi functions as an adapter protein that mediates pro-apoptotic signaling from poly-glutamine-expanded huntingtin, an established cause of Huntington disease, to the extrinsic cell death pathway. To explore other functions of Hippi we generated Hippi knock-out mice. This deletion causes randomization of the embryo turning process and heart looping, which are hallmarks of defective left–right (LR) axis patterning. We report that motile monocilia normally present at the surface of the embryonic node, and proposed to initiate the break in LR symmetry, are absent on Hippi−/− embryos. Furthermore, defects in central nervous system development are observed. The Sonic hedgehog (Shh) pathway is downregulated in the neural tube in the absence of Hippi, which results in failure to establish ventral neural cell fate. Together, these findings demonstrate a dual role for Hippi in cilia assembly and Shh signaling during development, in addition to its proposed role in apoptosis signal transduction in the adult brain under pathogenically stressful conditions. PMID:17027958

  13. Altered heparan sulfate structure in Glce(-/-) mice leads to increased Hedgehog signaling in endochondral bones.

    PubMed

    Dierker, Tabea; Bachvarova, Velina; Krause, Yvonne; Li, Jin-Ping; Kjellén, Lena; Seidler, Daniela G; Vortkamp, Andrea

    2016-01-01

    One of the key regulators of endochondral ossification is Indian hedgehog (Ihh), which acts as a long-range morphogen in the developing skeletal elements. Previous studies have shown that the distribution and signaling activity of Ihh is regulated by the concentration of the extracellular glycosaminoglycan heparan sulfate (HS). An essential step during biosynthesis of HS is the epimerization of D-glucuronic to L-iduronic acid by the enzyme glucuronyl C5-epimerase (Hsepi or Glce). Here we have investigated chondrocyte differentiation in Glce deficient mice and found increased regions of proliferating chondrocytes accompanied by a delayed onset of hypertrophic differentiation. In addition, we observed increased expression levels of the Ihh target genes Patched1 (Ptch1) and Parathyroid hormone related peptide (Pthrp; Parathyroid hormone like hormone (Pthlh)) indicating elevated Ihh signaling. We further show that Ihh binds with reduced affinity to HS isolated from Glce(-/-) mice. Together our results strongly indicate that not only the level, but also the structure of HS is critical in regulating the distribution and signaling activity of Ihh in chondrocytes. PMID:26116392

  14. Autonomous and nonautonomous roles of Hedgehog signaling in regulating limb muscle formation

    PubMed Central

    Hu, Jimmy Kuang-Hsien; McGlinn, Edwina; Harfe, Brian D.; Kardon, Gabrielle; Tabin, Clifford J.

    2012-01-01

    Muscle progenitor cells migrate from the lateral somites into the developing vertebrate limb, where they undergo patterning and differentiation in response to local signals. Sonic hedgehog (Shh) is a secreted molecule made in the posterior limb bud that affects patterning and development of multiple tissues, including skeletal muscles. However, the cell-autonomous and non-cell-autonomous functions of Shh during limb muscle formation have remained unclear. We found that Shh affects the pattern of limb musculature non-cell-autonomously, acting through adjacent nonmuscle mesenchyme. However, Shh plays a cell-autonomous role in maintaining cell survival in the dermomyotome and initiating early activation of the myogenic program in the ventral limb. At later stages, Shh promotes slow muscle differentiation cell-autonomously. In addition, Shh signaling is required cell-autonomously to regulate directional muscle cell migration in the distal limb. We identify neuroepithelial cell transforming gene 1 (Net1) as a downstream target and effector of Shh signaling in that context. PMID:22987639

  15. Hedgehog signaling maintains hair follicle stem cell phenotype in young and aged human skin.

    PubMed

    Rittié, Laure; Stoll, Stefan W; Kang, Sewon; Voorhees, John J; Fisher, Gary J

    2009-12-01

    Skin hair follicles (HF) contain bulge stem cells (SC) that regenerate HFs during hair cycles, and repair skin epithelia following injury. As natural aging is associated with decreased skin repair capacity in humans, we have investigated the impact of age on human scalp HF bulge cell number and function. Here, we isolated human bulge cells, characterized as CD200+/KRT15+/KRT19+ cells of the HF, by dissection-combined CD200 selection in young and aged human skin. Targeted transcriptional profiling indicates that KRT15, KRT19, Dkk3, Dkk4, Tcf3, S100A4, Gas1, EGFR and CTGF/CCN2 are also preferentially expressed by human bulge cells, compared to differentiated HF keratinocytes (KC). Our results demonstrate that aging does not alter expression or localization of these HF SC markers. In addition, we could not detect significant differences in HF density or bulge cell number between young and aged human scalp skin. Interestingly, hedgehog (Hh) signaling is activated in human bulge cells in vivo, and down-regulated in differentiated HF KCs, both in young and aged skin. In addition, activation of Hh signaling by lentivirus-mediated overexpression of transcription factor Gli1 induces transcription of HF SC markers KRT15, KRT19, and Gas1, in cultured KCs. Together with previously reported knock-out mouse results, these data suggest a role for Hh signaling in maintaining bulge cell phenotype in young and aged human skin.

  16. Costal2 Functions as a Microtubule-Dependent Motor in the Hedgehog Signal Transduction Pathway

    PubMed Central

    Farzan, Shohreh F.; Ascano, Manuel; Ogden, Stacey K.; Sanial, Matthieu; Brigui, Amira; Plessis, Anne; Robbins, David J.

    2009-01-01

    SUMMARY The Hedgehog (Hh) signaling pathway initiates an evolutionarily conserved developmental program required for the proper patterning of many tissues. Costal2 (Cos2) is a requisite component of the Hh pathway, whose mechanistic role is not well understood. Cos2 was initially predicted, based on its primary sequence, to function as a microtubule-associated (MT) molecular motor. However, despite being identified over a decade ago, evidence showing that Cos2 function might require kinesin-like properties has for the most part been lacking. Thus the prevailing dogma in the field is that Cos2 functions solely as a scaffolding protein during Hh signal transduction. Here, we provide the first evidence that Cos2 motility is required for its biological function, and that this motility may be Hh regulated. We show that Cos2 motility requires an active motor domain, ATP and microtubules. Additionally, Cos2 recruits and transports other components of the Hh signaling pathway, including the transcription factor Cubitus interruptus (Ci), throughout the cell. Drosophila expressing cos2 mutations that encode proteins that lack motility are attenuated in their ability to regulate Ci activity and exhibit phenotypes consistent with attenuated Cos2 function. Combined, these results demonstrate that Cos2 motility plays an important role in its function, regulating the amounts and activity of Ci that ultimately interpret the level of Hh to which cells are exposed. PMID:18691888

  17. Activation of sonic hedgehog signaling enhances cell migration and invasion by induction of matrix metalloproteinase-2 and -9 via the phosphoinositide-3 kinase/AKT signaling pathway in glioblastoma.

    PubMed

    Chang, Liang; Zhao, Dan; Liu, Hui-Bin; Wang, Qiu-Shi; Zhang, Ping; Li, Chen-Long; Du, Wen-Zhong; Wang, Hong-Jun; Liu, Xing; Zhang, Zhi-Ren; Jiang, Chuan-Lu

    2015-11-01

    Aberrant hedgehog signaling contributes to the development of various malignancies, including glioblastoma (GBM). However, the potential mechanism of hedgehog signaling in GBM migration and invasion has remained to be elucidated. The present study showed that enhanced hedgehog signaling by recombinant human sonic hedgehog N‑terminal peptide (rhSHH) promoted the adhesion, invasion and migration of GBM cells, accompanied by increases in mRNA and protein levels of matrix metalloproteinase‑2 (MMP‑2) and MMP‑9. However, inhibition of hedgehog signaling with cyclopamine suppressed the adhesion, invasion and migration of GBM cells, accompanied by decreases in mRNA and protein levels of MMP‑2 and ‑9. Furthermore, it was found that MMP‑2- and MMP‑9-neutralizing antibodies or GAM6001 reversed the inductive effects of rhSHH on cell migration and invasion. In addition, enhanced hedgehog signaling by rhSHH increased AKT phosphorylation, whereas blockade of hedgehog signaling decreased AKT phosphorylations. Further experiments showed that LY294002, an inhibitor of phosphoinositide-3 kinase (PI3K), decreased rhSHH‑induced upregulation of MMP‑2 and ‑9. Finally, the protein expression of glioblastoma-associated oncogene 1 was positively correlated with levels of phosphorylated AKT as well as protein expressions of MMP‑2 and ‑9 in GBM tissue samples. In conclusion, the present study indicated that the hedgehog pathway regulates GBM-cell migration and invasion by increasing MMP-2 and MMP-9 production via the PI3K/AKT pathway. PMID:26299938

  18. Differential involvement of Hedgehog signaling in butterfly wing and eyespot development.

    PubMed

    Tong, Xiaoling; Lindemann, Anna; Monteiro, Antónia

    2012-01-01

    Butterfly eyespots may have evolved from the recruitment of pre-existent gene circuits or regulatory networks into novel locations on the wing. Gene expression data suggests one such circuit, the Hedgehog (Hh) signaling pathway and its target gene engrailed (en), was recruited from a role in patterning the anterior-posterior insect wing axis to a role patterning butterfly eyespots. However, while Junonia coenia expresses hh and en both in the posterior compartment of the wing and in eyespot centers, Bicyclus anynana lacks hh eyespot-specific expression. This suggests that Hh signaling may not be functioning in eyespot development in either species or that it functions in J. coenia but not in B. anynana. In order to test these hypotheses, we performed functional tests of Hh signaling in these species. We investigated the effects of Hh protein sequestration during the larval stage on en expression levels, and on wing size and eyespot size in adults. Hh sequestration led to significantly reduced en expression and to significantly smaller wings and eyespots in both species. But while eyespot size in B. anynana was reduced proportionately to wing size, in J. coenia, eyespots were reduced disproportionately, indicating an independent role of Hh signaling in eyespot development in J. coenia. We conclude that while Hh signaling retains a conserved role in promoting wing growth across nymphalid butterflies, it plays an additional role in eyespot development in some, but not all, lineages of nymphalid butterflies. We discuss our findings in the context of alternative evolutionary scenarios that led to the differential expression of hh and other Hh pathway signaling members across nymphalid species. PMID:23227236

  19. Differential Involvement of Hedgehog Signaling in Butterfly Wing and Eyespot Development

    PubMed Central

    Monteiro, Antónia

    2012-01-01

    Butterfly eyespots may have evolved from the recruitment of pre-existent gene circuits or regulatory networks into novel locations on the wing. Gene expression data suggests one such circuit, the Hedgehog (Hh) signaling pathway and its target gene engrailed (en), was recruited from a role in patterning the anterior-posterior insect wing axis to a role patterning butterfly eyespots. However, while Junonia coenia expresses hh and en both in the posterior compartment of the wing and in eyespot centers, Bicyclus anynana lacks hh eyespot-specific expression. This suggests that Hh signaling may not be functioning in eyespot development in either species or that it functions in J. coenia but not in B. anynana. In order to test these hypotheses, we performed functional tests of Hh signaling in these species. We investigated the effects of Hh protein sequestration during the larval stage on en expression levels, and on wing size and eyespot size in adults. Hh sequestration led to significantly reduced en expression and to significantly smaller wings and eyespots in both species. But while eyespot size in B. anynana was reduced proportionately to wing size, in J. coenia, eyespots were reduced disproportionately, indicating an independent role of Hh signaling in eyespot development in J. coenia. We conclude that while Hh signaling retains a conserved role in promoting wing growth across nymphalid butterflies, it plays an additional role in eyespot development in some, but not all, lineages of nymphalid butterflies. We discuss our findings in the context of alternative evolutionary scenarios that led to the differential expression of hh and other Hh pathway signaling members across nymphalid species. PMID:23227236

  20. Differential involvement of Hedgehog signaling in butterfly wing and eyespot development.

    PubMed

    Tong, Xiaoling; Lindemann, Anna; Monteiro, Antónia

    2012-01-01

    Butterfly eyespots may have evolved from the recruitment of pre-existent gene circuits or regulatory networks into novel locations on the wing. Gene expression data suggests one such circuit, the Hedgehog (Hh) signaling pathway and its target gene engrailed (en), was recruited from a role in patterning the anterior-posterior insect wing axis to a role patterning butterfly eyespots. However, while Junonia coenia expresses hh and en both in the posterior compartment of the wing and in eyespot centers, Bicyclus anynana lacks hh eyespot-specific expression. This suggests that Hh signaling may not be functioning in eyespot development in either species or that it functions in J. coenia but not in B. anynana. In order to test these hypotheses, we performed functional tests of Hh signaling in these species. We investigated the effects of Hh protein sequestration during the larval stage on en expression levels, and on wing size and eyespot size in adults. Hh sequestration led to significantly reduced en expression and to significantly smaller wings and eyespots in both species. But while eyespot size in B. anynana was reduced proportionately to wing size, in J. coenia, eyespots were reduced disproportionately, indicating an independent role of Hh signaling in eyespot development in J. coenia. We conclude that while Hh signaling retains a conserved role in promoting wing growth across nymphalid butterflies, it plays an additional role in eyespot development in some, but not all, lineages of nymphalid butterflies. We discuss our findings in the context of alternative evolutionary scenarios that led to the differential expression of hh and other Hh pathway signaling members across nymphalid species.

  1. Analysis of Germline GLI1 Variation Implicates Hedgehog Signalling in the Regulation of Intestinal Inflammatory Pathways

    PubMed Central

    Tremelling, Mark; Noble, Colin L; Nimmo, Elaine R; Tenesa, Albert; Cornelius, Jennine; Torkvist, Leif; Kao, John; Farrington, Susan; Drummond, Hazel E; Ho, Gwo-Tzer; Arnott, Ian D. R; Appelman, Henry D; Diehl, Lauri; Campbell, Harry; Dunlop, Malcolm G; Parkes, Miles; Howie, Sarah E. M; Gumucio, Deborah L; Satsangi, Jack

    2008-01-01

    Background Ulcerative colitis (UC) and Crohn's disease (CD) are polygenic chronic inflammatory bowel diseases (IBD) of high prevalence that are associated with considerable morbidity. The hedgehog (HH) signalling pathway, which includes the transcription factor glioma-associated oncogene homolog 1 (GLI1), plays vital roles in gastrointestinal tract development, homeostasis, and malignancy. We identified a germline variation in GLI1 (within the IBD2 linkage region, 12q13) in patients with IBD. Since this IBD-associated variant encodes a GLI1 protein with reduced function and our expression studies demonstrated down-regulation of the HH response in IBD, we tested whether mice with reduced Gli1 activity demonstrate increased susceptibility to chemically induced colitis. Methods and Findings Using a gene-wide haplotype-tagging approach, germline GLI1 variation was examined in three independent populations of IBD patients and healthy controls from Northern Europe (Scotland, England, and Sweden) totalling over 5,000 individuals. On log-likelihood analysis, GLI1 was associated with IBD, predominantly UC, in Scotland and England (p < 0.0001). A nonsynonymous SNP (rs2228226C→G), in exon 12 of GLI1 (Q1100E) was strongly implicated, with pooled odds ratio of 1.194 (confidence interval = 1.09–1.31, p = 0.0002). GLI1 variants were tested in vitro for transcriptional activity in luciferase assays. Q1100E falls within a conserved motif near the C terminus of GLI1; the variant GLI protein exhibited reduced transactivation function in vitro. In complementary expression studies, we noted the colonic HH response, including GLI1, patched (PTCH), and hedgehog-interacting protein (HHIP), to be down-regulated in patients with UC. Finally, Gli1+/lacZ mice were tested for susceptibility to dextran sodium sulphate (DSS)-induced colitis. Clinical response, histology, and expression of inflammatory cytokines and chemokines were recorded. Gli1+/lacZ mice rapidly developed severe intestinal

  2. Distinctive expression patterns of Hedgehog pathway genes in the Ciona intestinalis larva: implications for a role of Hedgehog signaling in postembryonic development and chordate evolution.

    PubMed

    Islam, A F M Tariqul; Moly, Pricila Khan; Miyamoto, Yuki; Kusakabe, Takehiro G

    2010-02-01

    Members of the Hedgehog (Hh) family are soluble ligands that orchestrate a wide spectrum of developmental processes ranging from left-right axis determination of the embryo to tissue patterning and organogenesis. Tunicates, including ascidians, are the closest relatives of vertebrates, and elucidation of Hh signaling in ascidians should provide an important clue towards better understanding the role of this pathway in development. In previous studies, expression patterns of genes encoding Hh and its downstream factor Gli have been examined up to the tailbud stage in the ascidian embryo, but their expression in the larva has not been reported. Here we show the spatial expression patterns of hedgehog (Ci-hh1, Ci-hh2), patched (Ci-ptc), smoothened (Ci-smo), and Gli (Ci-Gli) orthologs in larvae of the ascidian Ciona intestinalis. The expression patterns of Ci-hh2 and Ci-Gli dramatically change during the period between the late tailbud embryo and the swimming larva. At the larval stage, expression of Ci-Gli was found in a central part of the endoderm and in the visceral ganglion, while Ci-hh2 was expressed in two discrete endodermal regions, anteriorly and posteriorly adjacent to the cells expressing Gli. The expression patterns of these genes suggest that the Hh ligand controls postembryonic development of the endoderm and the central nervous system. Expression of a gene encoding Hh in the anterior and/or pharyngeal endoderm is probably an ancient chordate character; diversification of regulation and targets of the Hh signaling in this region may have played a major role in the evolution of chordate body structures.

  3. Activation of Sonic hedgehog signaling in ventricular cardiomyocytes exerts cardioprotection against ischemia reperfusion injuries

    PubMed Central

    Paulis, Ludovit; Fauconnier, Jeremy; Cazorla, Olivier; Thireau, Jérome; Soleti, Raffaella; Vidal, Bastien; Ouillé, Aude; Bartholome, Marion; Bideaux, Patrice; Roubille, François; Le Guennec, Jean-Yves; Andriantsitohaina, Ramaroson; Martínez, M. Carmen; Lacampagne, Alain

    2015-01-01

    Sonic hedgehog (SHH) is a conserved protein involved in embryonic tissue patterning and development. SHH signaling has been reported as a cardio-protective pathway via muscle repair–associated angiogenesis. The goal of this study was to investigate the role of SHH signaling pathway in the adult myocardium in physiological situation and after ischemia-reperfusion. We show in a rat model of ischemia-reperfusion that stimulation of SHH pathway, either by a recombinant peptide or shed membranes microparticles harboring SHH ligand, prior to reperfusion reduces both infarct size and subsequent arrhythmias by preventing ventricular repolarization abnormalities. We further demonstrate in healthy animals a reduction of QTc interval mediated by NO/cGMP pathway leading to the shortening of ventricular cardiomyocytes action potential duration due to the activation of an inward rectifying potassium current sharing pharmacological and electrophysiological properties with ATP-dependent potassium current. Besides its effect on both angiogenesis and endothelial dysfunction we demonstrate here a novel cardio-protective effect of SHH acting directly on the cardiomyocytes. This emphasizes the pleotropic effect of SHH pathway as a potential cardiac therapeutic target. PMID:25613906

  4. Histone deacetylase 6 represents a novel drug target in the oncogenic Hedgehog signaling pathway.

    PubMed

    Dhanyamraju, Pavan Kumar; Holz, Philipp Simon; Finkernagel, Florian; Fendrich, Volker; Lauth, Matthias

    2015-03-01

    Uncontrolled Hedgehog (Hh) signaling is the cause of several malignancies, including the pediatric cancer medulloblastoma, a neuroectodermal tumor affecting the cerebellum. Despite the development of potent Hh pathway antagonists, medulloblastoma drug resistance is still an unresolved issue that requires the identification of novel drug targets. Following up on our observation that histone deacetylase 6 (HDAC6) expression was increased in Hh-driven medulloblastoma, we found that this enzyme is essential for full Hh pathway activation. Intriguingly, these stimulatory effects of HDAC6 are partly integrated downstream of primary cilia, a known HDAC6-regulated structure. In addition, HDAC6 is also required for the complete repression of basal Hh target gene expression. These contrasting effects are mediated by HDAC6's impact on Gli2 mRNA and GLI3 protein expression. As a result of this complex interaction with Hh signaling, global transcriptome analysis revealed that HDAC6 regulates only a subset of Smoothened- and Gli-driven genes, including all well-established Hh targets such as Ptch1 or Gli1. Importantly, medulloblastoma cell survival was severely compromised by HDAC6 inhibition in vitro and pharmacologic HDAC6 blockade strongly reduced tumor growth in an in vivo allograft model. In summary, our data describe an important role for HDAC6 in regulating the mammalian Hh pathway and encourage further studies focusing on HDAC6 as a novel drug target in medulloblastoma. PMID:25552369

  5. The Impact of Hedgehog Signaling Pathway on DNA Repair Mechanisms in Human Cancer

    PubMed Central

    Meng, Erhong; Hanna, Ann; Samant, Rajeev S.; Shevde, Lalita A.

    2015-01-01

    Defined cellular mechanisms have evolved that recognize and repair DNA to protect the integrity of its structure and sequence when encountering assaults from endogenous and exogenous sources. There are five major DNA repair pathways: mismatch repair, nucleotide excision repair, direct repair, base excision repair and DNA double strand break repair (including non-homologous end joining and homologous recombination repair). Aberrant activation of the Hedgehog (Hh) signaling pathway is a feature of many cancer types. The Hh pathway has been documented to be indispensable for epithelial-mesenchymal transition, invasion and metastasis, cancer stemness, and chemoresistance. The functional transcription activators of the Hh pathway include the GLI proteins. Inhibition of the activity of GLI can interfere with almost all DNA repair types in human cancer, indicating that Hh/GLI functions may play an important role in enabling tumor cells to survive lethal types of DNA damage induced by chemotherapy and radiotherapy. Thus, Hh signaling presents an important therapeutic target to overcome DNA repair-enabled multi-drug resistance and consequently increase chemotherapeutic response in the treatment of cancer. PMID:26197339

  6. Tamoxifen Treatment of Breast Cancer Cells: Impact on Hedgehog/GLI1 Signaling.

    PubMed

    Villegas, Victoria E; Rondón-Lagos, Milena; Annaratone, Laura; Castellano, Isabella; Grismaldo, Adriana; Sapino, Anna; Zaphiropoulos, Peter G

    2016-01-01

    The selective estrogen receptor (ER) modulator tamoxifen (TAM) has become the standard therapy for the treatment of ER+ breast cancer patients. Despite the obvious benefits of TAM, a proportion of patients acquire resistance to treatment, and this is a significant clinical problem. Consequently, the identification of possible mechanisms involved in TAM-resistance should help the development of new therapeutic targets. In this study, we present in vitro data using a panel of different breast cancer cell lines and demonstrate the modulatory effect of TAM on cellular proliferation and expression of Hedgehog signaling components, including the terminal effector of the pathway, the transcription factor GLI1. A variable pattern of expression following TAM administration was observed, reflecting the distinctive properties of the ER+ and ER- cell lines analyzed. Remarkably, the TAM-induced increase in the proliferation of the ER+ ZR-75-1 and BT474 cells parallels a sustained upregulation of GLI1 expression and its translocation to the nucleus. These findings, implicating a TAM-GLI1 signaling cross-talk, could ultimately be exploited not only as a means for novel prognostication markers but also in efforts to effectively target breast cancer subtypes. PMID:26927093

  7. Transcriptome Changes Affecting Hedgehog and Cytokine Signalling in the Umbilical Cord: Implications for Disease Risk

    PubMed Central

    Stünkel, Walter; Tng, Emilia; Tan, Jun Hao; Chen, Li; Joseph, Roy; Cheong, Clara Y.; Ong, Mei-Lyn; Lee, Yung Seng; Chong, Yap-Seng; Saw, Seang Mei; Meaney, Michael J.; Kwek, Kenneth; Sheppard, Allan M.; Gluckman, Peter D.; Holbrook, Joanna D.

    2012-01-01

    Background Babies born at lower gestational ages or smaller birthweights have a greater risk of poorer health in later life. Both the causes of these sub-optimal birth outcomes and the mechanism by which the effects are transmitted over decades are the subject of extensive study. We investigated whether a transcriptomic signature of either birthweight or gestational age could be detected in umbilical cord RNA. Methods The gene expression patterns of 32 umbilical cords from Singaporean babies of Chinese ethnicity across a range of birthweights (1698–4151 g) and gestational ages (35–41 weeks) were determined. We confirmed the differential expression pattern by gestational age for 12 genes in a series of 127 umbilical cords of Chinese, Malay and Indian ethnicity. Results We found that the transcriptome is substantially influenced by gestational age; but less so by birthweight. We show that some of the expression changes dependent on gestational age are enriched in signal transduction pathways, such as Hedgehog and in genes with roles in cytokine signalling and angiogenesis. We show that some of the gene expression changes we report are reflected in the epigenome. Conclusions We studied the umbilical cord which is peripheral to disease susceptible tissues. The results suggest that soma-wide transcriptome changes, preserved at the epigenetic level, may be a mechanism whereby birth outcomes are linked to the risk of adult metabolic and arthritic disease and suggest that greater attention be given to the association between premature birth and later disease risk. PMID:22808055

  8. Gorab Is Required for Dermal Condensate Cells to Respond to Hedgehog Signals during Hair Follicle Morphogenesis.

    PubMed

    Liu, Ying; Snedecor, Elizabeth R; Choi, Yeon Ja; Yang, Ning; Zhang, Xu; Xu, Yuhuan; Han, Yunlin; Jones, Evan C; Shroyer, Kenneth R; Clark, Richard A; Zhang, Lianfeng; Qin, Chuan; Chen, Jiang

    2016-02-01

    GORAB is a golgin that localizes predominantly at the Golgi apparatus and physically interacts with small guanosine triphosphatases. GORAB is ubiquitously expressed in mammalian tissues, including the skin. However, the biological function of this golgin in skin is unknown. Here, we report that disrupting the expression of the Gorab gene in mice results in hair follicle morphogenesis defects that were characterized by impaired follicular keratinocyte differentiation. This hair follicle phenotype was associated with markedly suppressed hedgehog (Hh) signaling pathway in dermal condensates in vivo. Gorab-deficient dermal mesenchymal cells also displayed a significantly reduced capability to respond to Hh pathway activation in vitro. Furthermore, we found that the formation of the primary cilium, a cellular organelle that is essential for the Hh pathway, was impaired in mutant dermal condensate cells, suggesting that Gorab may be required for the Hh pathway through facilitating the formation of primary cilia. Thus, data obtained from this study provided insight into the biological functions of Gorab during embryonic morphogenesis of the skin in which Hh signaling and primary cilia exert important functions. PMID:26967474

  9. Hedgehog signaling maintains a tumor stem cell compartment in multiple myeloma.

    PubMed

    Peacock, Craig D; Wang, Qiuju; Gesell, Gregory S; Corcoran-Schwartz, Ian M; Jones, Evan; Kim, Jynho; Devereux, Wendy L; Rhodes, Jonathan T; Huff, Carol A; Beachy, Philip A; Watkins, D Neil; Matsui, William

    2007-03-01

    The cancer stem cell hypothesis suggests that malignant growth depends on a subset of tumor cells with stem cell-like properties of self-renewal. Because hedgehog (Hh) signaling regulates progenitor cell fate in normal development and homeostasis, aberrant pathway activation might be involved in the maintenance of such a population in cancer. Indeed, mutational activation of the Hh pathway is associated with medulloblastoma and basal cell carcinoma; pathway activity is also critical for growth of other tumors lacking such mutations, although the mechanism of pathway activation is poorly understood. Here we study the role and mechanism of Hh pathway activation in multiple myeloma (MM), a malignancy with a well defined stem cell compartment. In this model, rare malignant progenitors capable of clonal expansion resemble B cells, whereas the much larger tumor cell population manifests a differentiated plasma cell phenotype that pathologically defines the disease. We show that the subset of MM cells that manifests Hh pathway activity is markedly concentrated within the tumor stem cell compartment. The Hh ligand promotes expansion of MM stem cells without differentiation, whereas the Hh pathway blockade, while having little or no effect on malignant plasma cell growth, markedly inhibits clonal expansion accompanied by terminal differentiation of purified MM stem cells. These data reveal that Hh pathway activation is heterogeneous across the spectrum of MM tumor stem cells and their more differentiated progeny. The potential existence of similar relationships in other adult cancers may have important biologic and clinical implications for the study of aberrant Hh signaling.

  10. Gorab is required for dermal condensate cells to respond to hedgehog signals during hair follicle morphogenesis

    PubMed Central

    Liu, Ying; Snedecor, Elizabeth R.; Choi, Yeon Ja; Yang, Ning; Zhang, Xu; Xu, Yuhuan; Han, Yunlin; Jones, Evan C.; Shroyer, Kenneth R.; Clark, Richard A.; Zhang, Lianfeng; Qin, Chuan; Chen, Jiang

    2015-01-01

    GORAB is a golgin that localizes predominantly at the Golgi apparatus and physically interacts with small GTPases. GORAB is ubiquitously expressed in mammalian tissues, including the skin. However, the biological function of this golgin in skin is unknown. Here, we report that disrupting the expression of the Gorab gene in mice results in hair follicle morphogenesis defects that were characterized by impaired follicular keratinocyte differentiation. This hair follicle phenotype was associated with markedly suppressed hedgehog (Hh) signaling pathway in dermal condensates in vivo. Gorab-deficient dermal mesenchymal cells also displayed significantly reduced capability to respond to Hh pathway activation in vitro. Furthermore, we found that the formation of primary cilium, a cellular organelle that is essential for the Hh pathway, was impaired in mutant dermal papilla cells, suggesting that Gorab may be required for the Hh pathway through facilitating the formation of primary cilia. Thus, data obtained from this study provided insight onto the biological functions of Gorab during embryonic morphogenesis of skin in which Hh signaling and primary cilia exert important functions. PMID:26967474

  11. Targeting the Sonic Hedgehog Signaling Pathway: Review of Smoothened and GLI Inhibitors

    PubMed Central

    Rimkus, Tadas K.; Carpenter, Richard L.; Qasem, Shadi; Chan, Michael; Lo, Hui-Wen

    2016-01-01

    The sonic hedgehog (Shh) signaling pathway is a major regulator of cell differentiation, cell proliferation, and tissue polarity. Aberrant activation of the Shh pathway has been shown in a variety of human cancers, including, basal cell carcinoma, malignant gliomas, medulloblastoma, leukemias, and cancers of the breast, lung, pancreas, and prostate. Tumorigenesis, tumor progression and therapeutic response have all been shown to be impacted by the Shh signaling pathway. Downstream effectors of the Shh pathway include smoothened (SMO) and glioma-associated oncogene homolog (GLI) family of zinc finger transcription factors. Both are regarded as important targets for cancer therapeutics. While most efforts have been devoted towards pharmacologically targeting SMO, developing GLI-targeted approach has its merit because of the fact that GLI proteins can be activated by both Shh ligand-dependent and -independent mechanisms. To date, two SMO inhibitors (LDE225/Sonidegib and GDC-0449/Vismodegib) have received FDA approval for treating basal cell carcinoma while many clinical trials are being conducted to evaluate the efficacy of this exciting class of targeted therapy in a variety of cancers. In this review, we provide an overview of the biology of the Shh pathway and then detail the current landscape of the Shh-SMO-GLI pathway inhibitors including those in preclinical studies and clinical trials. PMID:26891329

  12. Sedum sarmentosum Bunge extract induces apoptosis and inhibits proliferation in pancreatic cancer cells via the hedgehog signaling pathway.

    PubMed

    Bai, Yongheng; Chen, Bicheng; Hong, Weilong; Liang, Yong; Zhou, Mengtao; Zhou, Lan

    2016-05-01

    Sedum sarmentosum Bunge, a traditional Chinese herbal medicine, has a wide range of clinical applications including antibiosis, anti-inflammation and anti-oxidation. In the present study, we identified that its extract (SSBE) exerts pancreatic anticancer activity in vitro and in vivo. In the cultured pancreatic cancer PANC-1 cell line, SSBE inhibited cell growth in a concentration-dependent manner, and it was accompanied by the downregulated expression of proliferating cell nuclear antigen (PCNA). In addition, SSBE treatment also increased cellular apoptosis in a mitochondrial-dependent manner. Moreover, SSBE induced p53 expression, reduced c-Myc expression, and inhibited epithelial-mesenchymal transition (EMT). The antiproliferative activity of SSBE in the pancreatic cancer cells was found to be closely related to cell cycle arrest at the G2/M phase by upregulating p21(Waf1/CIP1) expression. Further study showed that this inhibitory effect of SSBE was through downregulation of the activity of the proliferation-related Hedgehog signaling pathway. Exogenous recombinant protein Shh was used to activate Hedgehog signaling, thereby resulting in the abolishment of the SSBE-mediated inhibition of pancreatic cancer cell growth. In animal xenograft models of pancreatic cancer, activated Hedgehog signaling was also observed compared with the vehicle controls, but was reduced by SSBE administration. As a result, SSBE suppressed the growth of pancreatic tumors. Thus, these findings demonstrate that SSBE has therapeutic potential for pancreatic cancer, and this anticancer effect in pancreatic cancer cells is associated with inhibition of the Hedgehog signaling pathway. PMID:26987050

  13. RNA editing of the GLI1 transcription factor modulates the output of Hedgehog signaling.

    PubMed

    Shimokawa, Takashi; Rahman, Mohammed Ferdous-Ur; Tostar, Ulrica; Sonkoly, Enikö; Ståhle, Mona; Pivarcsi, Andor; Palaniswamy, Ramesh; Zaphiropoulos, Peter G

    2013-02-01

    The Hedgehog (HH) signaling pathway has important roles in tumorigenesis and in embryonal patterning. The Glioma-associated oncogene 1 (GLI1) is a key molecule in HH signaling, acting as a transcriptional effector and, moreover, is considered to be a potential therapeutic target for several types of cancer. To extend our previous focus on the implications of alternative splicing for HH signal transduction, we now report on an additional post-transcriptional mechanism with an impact on GLI1 activity, namely RNA editing. The GLI1 mRNA is highly edited at nucleotide 2179 by adenosine deamination in normal cerebellum, but the extent of this modification is reduced in cell lines from the cerebellar tumor medulloblastoma. Additionally, basal cell carcinoma tumor samples exhibit decreased GLI1 editing compared with normal skin. Interestingly, knocking down of either ADAR1 or ADAR2 reduces RNA editing of GLI1. This adenosine to inosine substitution leads to a change from Arginine to Glycine at position 701 that influences not only GLI1 transcriptional activity, but also GLI1-dependent cellular proliferation. Specifically, the edited GLI1, GLI1-701G, has a higher capacity to activate most of the transcriptional targets tested and is less susceptible to inhibition by the negative regulator of HH signaling suppressor of fused. However, the Dyrk1a kinase, implicated in cellular proliferation, is more effective in increasing the transcriptional activity of the non-edited GLI1. Finally, introduction of GLI1-701G into medulloblastoma cells confers a smaller increase in cellular growth relative to GLI1. In conclusion, our findings indicate that RNA editing of GLI1 is a regulatory mechanism that modulates the output of the HH signaling pathway. PMID:23324600

  14. Induction of MITF expression in human cholangiocarcinoma cells and hepatocellular carcinoma cells by cyclopamine, an inhibitor of the Hedgehog signaling.

    PubMed

    Samatiwat, Papavee; Takeda, Kazuhisa; Satarug, Soisungwan; Ohba, Koji; Kukongviriyapan, Veerapol; Shibahara, Shigeki

    2016-01-29

    Microphthalmia-associated transcription factor (MITF) is a key regulator of differentiation of melanocytes and retinal pigment epithelial cells, but it also has functions in non-pigment cells. MITF consists of multiple isoforms, including widely expressed MITF-A and MITF-H. In the present study, we explored the potential role played by the Hedgehog signaling on MITF expression in two common types of primary liver cancer, using human cholangiocarcinoma cell lines, the KKU-100 and HuCCT1, along with the HepG2 human hepatocellular carcinoma cell line. Importantly, cholangiocarcinoma is characterized by the activated Hedgehog signaling. Here we show that MITF-A mRNA is predominantly expressed in all three human liver cancer cell lines examined. Moreover, cyclopamine, an inhibitor of the Hedgehog signalling, increased the expression levels of MITF proteins in HuCCT1 and HepG2 cells, but not in KKU-100 cells, suggesting that MITF expression may be down-regulated in some liver cancer cases. PMID:26773496

  15. Metformin exerts anticancer effects through the inhibition of the Sonic hedgehog signaling pathway in breast cancer

    PubMed Central

    FAN, CONG; WANG, YUNSHAN; LIU, ZIMING; SUN, YING; WANG, XIUWEN; WEI, GUANGWEI; WEI, JUNMIN

    2015-01-01

    Metformin, a widely prescribed antidiabetic drug, has previously been shown to lower the risk of certain types of cancer, including that of breast cancer, and to improve prognosis. Its anticancer effects, which are mediated by the activation of AMP-activated protein kinase (AMPK), have become notable. The Sonic hedgehog (Shh) signaling pathway is involved in changes in mammary ducts and malignant transformation. The aim of the present study was to elucidate the role of the Shh pathway in mediating the anticancer effects of metformin and the correlation between AMPK and the Shh pathway. We investigated the effectiveness of metformin in inhibiting the proliferation, migration, invasion and stemness of breast cancer cells in vitro using RNA extraction and reverse transcription-polymerase chain reaction (RT-PCR), western blot analysis, cell proliferation assay, scratch-wound assay (cell migration assay), cell invasion assay, mammosphere culture and flow cytometry. In in vivo experiments, a tumor xenograft model was used to detect the effects of metformin on cancer cell proliferation. The results revealed that the treatment of breast cancer cells with metformin led to the inhibition of the Shh signaling pathway. Importantly, metformin inhibited recombinant human Shh (rhShh)-induced cell migration, invasion, and stemness, and impaired cell proliferation both in vitro and in vivo. Furthermore, the small interfering RNA (siRNA)-mediated downregulation of AMPK reversed the inhibitory effects of metformin on rhShh-induced Gli-1 expression and stemness. Our findings identified a role of the Shh signaling pathway in the anticancer effects of metformin in breast cancer. Furthermore, we revealed that the metformin-mediated inhibition of the Shh signaling pathway may be dependent on AMPK. PMID:25999130

  16. Metformin exerts anticancer effects through the inhibition of the Sonic hedgehog signaling pathway in breast cancer.

    PubMed

    Fan, Cong; Wang, Yunshan; Liu, Ziming; Sun, Ying; Wang, Xiuwen; Wei, Guangwei; Wei, Junmin

    2015-07-01

    Metformin, a widely prescribed antidiabetic drug, has previously been shown to lower the risk of certain types of cancer, including that of breast cancer, and to improve prognosis. Its anticancer effects, which are mediated by the activation of AMP-activated protein kinase (AMPK), have become notable. The Sonic hedgehog (Shh) signaling pathway is involved in changes in mammary ducts and malignant transformation. The aim of the present study was to elucidate the role of the Shh pathway in mediating the anticancer effects of metformin and the correlation between AMPK and the Shh pathway. We investigated the effectiveness of metformin in inhibiting the proliferation, migration, invasion and stemness of breast cancer cells in vitro using RNA extraction and reverse transcription‑polymerase chain reaction (RT-PCR), western blot analysis, cell proliferation assay, scratch-wound assay (cell migration assay), cell invasion assay, mammosphere culture and flow cytometry. In in vivo experiments, a tumor xenograft model was used to detect the effects of metformin on cancer cell proliferation. The results revealed that the treatment of breast cancer cells with metformin led to the inhibition of the Shh signaling pathway. Importantly, metformin inhibited recombinant human Shh (rhShh)‑induced cell migration, invasion, and stemness, and impaired cell proliferation both in vitro and in vivo. Furthermore, the small interfering RNA (siRNA)‑mediated downregulation of AMPK reversed the inhibitory effects of metformin on rhShh‑induced Gli-1 expression and stemness. Our findings identified a role of the Shh signaling pathway in the anticancer effects of metformin in breast cancer. Furthermore, we revealed that the metformin-mediated inhibition of the Shh signaling pathway may be dependent on AMPK. PMID:25999130

  17. Integrated QSAR study for inhibitors of hedgehog signal pathway against multiple cell lines:a collaborative filtering method

    PubMed Central

    2012-01-01

    Background The Hedgehog Signaling Pathway is one of signaling pathways that are very important to embryonic development. The participation of inhibitors in the Hedgehog Signal Pathway can control cell growth and death, and searching novel inhibitors to the functioning of the pathway are in a great demand. As the matter of fact, effective inhibitors could provide efficient therapies for a wide range of malignancies, and targeting such pathway in cells represents a promising new paradigm for cell growth and death control. Current research mainly focuses on the syntheses of the inhibitors of cyclopamine derivatives, which bind specifically to the Smo protein, and can be used for cancer therapy. While quantitatively structure-activity relationship (QSAR) studies have been performed for these compounds among different cell lines, none of them have achieved acceptable results in the prediction of activity values of new compounds. In this study, we proposed a novel collaborative QSAR model for inhibitors of the Hedgehog Signaling Pathway by integration the information from multiple cell lines. Such a model is expected to substantially improve the QSAR ability from single cell lines, and provide useful clues in developing clinically effective inhibitors and modifications of parent lead compounds for target on the Hedgehog Signaling Pathway. Results In this study, we have presented: (1) a collaborative QSAR model, which is used to integrate information among multiple cell lines to boost the QSAR results, rather than only a single cell line QSAR modeling. Our experiments have shown that the performance of our model is significantly better than single cell line QSAR methods; and (2) an efficient feature selection strategy under such collaborative environment, which can derive the commonly important features related to the entire given cell lines, while simultaneously showing their specific contributions to a specific cell-line. Based on feature selection results, we have

  18. Zebrafish con/disp1 reveals multiple spatiotemporal requirements for Hedgehog-signaling in craniofacial development

    PubMed Central

    2009-01-01

    Background The vertebrate head skeleton is derived largely from cranial neural crest cells (CNCC). Genetic studies in zebrafish and mice have established that the Hedgehog (Hh)-signaling pathway plays a critical role in craniofacial development, partly due to the pathway's role in CNCC development. Disruption of the Hh-signaling pathway in humans can lead to the spectral disorder of Holoprosencephaly (HPE), which is often characterized by a variety of craniofacial defects including midline facial clefting and cyclopia [1,2]. Previous work has uncovered a role for Hh-signaling in zebrafish dorsal neurocranium patterning and chondrogenesis, however Hh-signaling mutants have not been described with respect to the ventral pharyngeal arch (PA) skeleton. Lipid-modified Hh-ligands require the transmembrane-spanning receptor Dispatched 1 (Disp1) for proper secretion from Hh-synthesizing cells to the extracellular field where they act on target cells. Here we study chameleon mutants, lacking a functional disp1(con/disp1). Results con/disp1 mutants display reduced and dysmorphic mandibular and hyoid arch cartilages and lack all ceratobranchial cartilage elements. CNCC specification and migration into the PA primorida occurs normally in con/disp1 mutants, however disp1 is necessary for post-migratory CNCC patterning and differentiation. We show that disp1 is required for post-migratory CNCC to become properly patterned within the first arch, while the gene is dispensable for CNCC condensation and patterning in more posterior arches. Upon residing in well-formed pharyngeal epithelium, neural crest condensations in the posterior PA fail to maintain expression of two transcription factors essential for chondrogenesis, sox9a and dlx2a, yet continue to robustly express other neural crest markers. Histology reveals that posterior arch residing-CNCC differentiate into fibrous-connective tissue, rather than becoming chondrocytes. Treatments with Cyclopamine, to inhibit Hh-signaling

  19. Structural insights into human Kif7, a kinesin involved in Hedgehog signalling

    SciTech Connect

    Klejnot, Marta Kozielski, Frank

    2012-02-01

    The human Kif7 motor domain structure provides insights into a kinesin of medical significance. Kif7, a member of the kinesin 4 superfamily, is implicated in a variety of diseases including Joubert, hydrolethalus and acrocallosal syndromes. It is also involved in primary cilium formation and the Hedgehog signalling pathway and may play a role in cancer. Its activity is crucial for embryonic development. Kif7 and Kif27, a closely related kinesin in the same subfamily, are orthologues of the Drosophila melano@@gaster kinesin-like protein Costal-2 (Cos2). In vertebrates, they work together to fulfil the role of the single Cos2 gene in Drosophila. Here, the high-resolution structure of the human Kif7 motor domain is reported and is compared with that of conventional kinesin, the founding member of the kinesin superfamily. These data are a first step towards structural characterization of a kinesin-4 family member and of this interesting molecular motor of medical significance.

  20. Differential role of Hedgehog signaling in human pancreatic (patho-) physiology: An up to date review.

    PubMed

    Klieser, Eckhard; Swierczynski, Stefan; Mayr, Christian; Jäger, Tarkan; Schmidt, Johanna; Neureiter, Daniel; Kiesslich, Tobias; Illig, Romana

    2016-05-15

    Since the discovery of the Hedgehog (Hh) pathway in drosophila melanogaster, our knowledge of the role of Hh in embryonic development, inflammation, and cancerogenesis in humans has dramatically increased over the last decades. This is the case especially concerning the pancreas, however, real therapeutic breakthroughs are missing until now. In general, Hh signaling is essential for pancreatic organogenesis, development, and tissue maturation. In the case of acute pancreatitis, Hh has a protective role, whereas in chronic pancreatitis, Hh interacts with pancreatic stellate cells, leading to destructive parenchym fibrosis and atrophy, as well as to irregular tissue remodeling with potency of initiating cancerogenesis. In vitro and in situ analysis of Hh in pancreatic cancer revealed that the Hh pathway participates in the development of pancreatic precursor lesions and ductal adenocarcinoma including critical interactions with the tumor microenvironment. The application of specific inhibitors of components of the Hh pathway is currently subject of ongoing clinical trials (phases 1 and 2). Furthermore, a combination of Hh pathway inhibitors and established chemotherapeutic drugs could also represent a promising therapeutic approach. In this review, we give a structured survey of the role of the Hh pathway in pancreatic development, pancreatitis, pancreatic carcinogenesis and pancreatic cancer as well as an overview of current clinical trials concerning Hh pathway inhibitors and pancreas cancer.

  1. Differential role of Hedgehog signaling in human pancreatic (patho-) physiology: An up to date review

    PubMed Central

    Klieser, Eckhard; Swierczynski, Stefan; Mayr, Christian; Jäger, Tarkan; Schmidt, Johanna; Neureiter, Daniel; Kiesslich, Tobias; Illig, Romana

    2016-01-01

    Since the discovery of the Hedgehog (Hh) pathway in drosophila melanogaster, our knowledge of the role of Hh in embryonic development, inflammation, and cancerogenesis in humans has dramatically increased over the last decades. This is the case especially concerning the pancreas, however, real therapeutic breakthroughs are missing until now. In general, Hh signaling is essential for pancreatic organogenesis, development, and tissue maturation. In the case of acute pancreatitis, Hh has a protective role, whereas in chronic pancreatitis, Hh interacts with pancreatic stellate cells, leading to destructive parenchym fibrosis and atrophy, as well as to irregular tissue remodeling with potency of initiating cancerogenesis. In vitro and in situ analysis of Hh in pancreatic cancer revealed that the Hh pathway participates in the development of pancreatic precursor lesions and ductal adenocarcinoma including critical interactions with the tumor microenvironment. The application of specific inhibitors of components of the Hh pathway is currently subject of ongoing clinical trials (phases 1 and 2). Furthermore, a combination of Hh pathway inhibitors and established chemotherapeutic drugs could also represent a promising therapeutic approach. In this review, we give a structured survey of the role of the Hh pathway in pancreatic development, pancreatitis, pancreatic carcinogenesis and pancreatic cancer as well as an overview of current clinical trials concerning Hh pathway inhibitors and pancreas cancer. PMID:27190692

  2. WIP1 modulates responsiveness to Sonic Hedgehog signaling in neuronal precursor cells and medulloblastoma

    PubMed Central

    Wen, Jing; Lee, Juhyun; Malhotra, Anshu; Nahta, Rita; Arnold, Amanda R.; Buss, Meghan C.; Brown, Briana D.; Maier, Caroline; Kenney, Anna M.; Remke, Marc; Ramaswamy, Vijay; Taylor, Michael D.; Castellino, Robert C.

    2016-01-01

    High-level amplification of the protein phosphatase PPM1D (WIP1) is present in a subset of medulloblastomas (MBs) that have an expression profile consistent with active Sonic Hedgehog (SHH) signaling. We found that WIP1 overexpression increased expression of Shh target genes and cell proliferation in response to Shh stimulation in NIH3T3 and cerebellar granule neuron precursor (cGNP) cells in a p53-independent manner. Thus, we developed a mouse in which WIP1 is expressed in the developing brain under control of the Neurod2 promoter (ND2:WIP1). The external granule layer in early post-natal ND2:WIP1 mice exhibited increased proliferation and expression of Shh downstream targets. MB incidence increased and survival decreased when ND2:WIP1 mice were crossed with a Shh-activated MB mouse model. Conversely, Wip1 knock out significantly suppressed MB formation in two independent mouse models of Shh-activated MB. Furthermore, Wip1 knock-down or treatment with a WIP1 inhibitor suppressed the effects of Shh stimulation and potentiated the growth inhibitory effects of SHH pathway-inhibiting drugs in Shh-activated MB cells in vitro. This suggests an important cross-talk between SHH and WIP1 pathways that accelerates tumorigenesis and supports WIP1 inhibition as a potential treatment strategy for MB. PMID:27086929

  3. Crocetinic acid inhibits hedgehog signaling to inhibit pancreatic cancer stem cells

    PubMed Central

    Rangarajan, Parthasarathy; Subramaniam, Dharmalingam; Paul, Santanu; Kwatra, Deep; Palaniyandi, Kanagaraj; Islam, Shamima; Harihar, Sitaram; Ramalingam, Satish; Gutheil, William; Putty, Sandeep; Pradhan, Rohan; Padhye, Subhash; Welch, Danny R.; Anant, Shrikant; Dhar, Animesh

    2015-01-01

    Pancreatic cancer is the fourth leading cause of cancer deaths in the US and no significant treatment is currently available. Here, we describe the effect of crocetinic acid, which we purified from commercial saffron compound crocetin using high performance liquid chromatography. Crocetinic acid inhibits proliferation of pancreatic cancer cell lines in a dose- and time-dependent manner. In addition, it induced apoptosis. Moreover, the compound significantly inhibited epidermal growth factor receptor and Akt phosphorylation. Furthermore, crocetinic acid decreased the number and size of the pancospheres in a dose-dependent manner, and suppressed the expression of the marker protein DCLK-1 (Doublecortin Calcium/Calmodulin-Dependent Kinase-1) suggesting that crocetinic acid targets cancer stem cells (CSC). To understand the mechanism of CSC inhibition, the signaling pathways affected by purified crocetinic acid were dissected. Sonic hedgehog (Shh) upon binding to its cognate receptor patched, allows smoothened to accumulate and activate Gli transcription factor. Crocetinic acid inhibited the expression of both Shh and smoothened. Finally, these data were confirmed in vivo where the compound at a dose of 0.5 mg/Kg bw suppressed growth of tumor xenografts. Collectively, these data suggest that purified crocetinic acid inhibits pancreatic CSC, thereby inhibiting pancreatic tumorigenesis. PMID:26317547

  4. Sonic hedgehog signaling regulates amygdalar neurogenesis and extinction of fear memory.

    PubMed

    Hung, Hui-Chi; Hsiao, Ya-Hsin; Gean, Po-Wu

    2015-10-01

    It is now recognized that neurogenesis occurs throughout life predominantly in the subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ) of the lateral ventricle. In the present study, we investigated the relationship between neurogenesis in the amygdala and extinction of fear memory. Mice received 15 tone-footshock pairings. Twenty-four hours after training, the mice were given 15 tone-alone trials (extinction training) once per day for 7 days. Two hours before extinction training, the mice were injected intraperitoneally with 5-bromo-3-deoxyuridine (BrdU). BrdU-positive and NeuN-positive cells were analyzed 52 days after the training. A group of mice that received tone-footshock pairings but no extinction training served as controls (FC+No-Ext). The number of BrdU(+)/NeuN(+) cells was significantly higher in the extinction (FC+Ext) than in the FC+No-Ext mice. Proliferation inhibitor methylazoxymethanol acetate (MAM) or DNA synthesis inhibitor cytosine arabinoside (Ara-C) reduced neurogenesis and retarded extinction. Silencing Sonic hedgehog (Shh) gene with short hairpin interfering RNA (shRNA) by means of a retrovirus expression system to knockdown Shh specifically in the mitotic neurons reduced neurogenesis and retarded extinction. By contrast, over-expression of Shh increased neurogenesis and facilitated extinction. These results suggest that amygdala neurogenesis and Shh signaling are involved in the extinction of fear memory.

  5. Hedgehog signaling drives radioresistance and stroma-driven tumor repopulation in head and neck squamous cancers.

    PubMed

    Gan, Gregory N; Eagles, Justin; Keysar, Stephen B; Wang, Guoliang; Glogowska, Magdalena J; Altunbas, Cem; Anderson, Ryan T; Le, Phuong N; Morton, J Jason; Frederick, Barbara; Raben, David; Wang, Xiao-Jing; Jimeno, Antonio

    2014-12-01

    Local control and overall survival in patients with advanced head and neck squamous cell cancer (HNSCC) remains dismal. Signaling through the Hedgehog (Hh) pathway is associated with epithelial-to-mesenchymal transition, and activation of the Hh effector transcription factor Gli1 is a poor prognostic factor in this disease setting. Here, we report that increased GLI1 expression in the leading edge of HNSCC tumors is further increased by irradiation, where it contributes to therapeutic inhibition. Hh pathway blockade with cyclopamine suppressed GLI1 activation and enhanced tumor sensitivity to radiotherapy. Furthermore, radiotherapy-induced GLI1 expression was mediated in part by the mTOR/S6K1 pathway. Stroma exposed to radiotherapy promoted rapid tumor repopulation, and this effect was suppressed by Hh inhibition. Our results demonstrate that Gli1 that is upregulated at the tumor-stroma intersection in HNSCC is elevated by radiotherapy, where it contributes to stromal-mediated resistance, and that Hh inhibitors offer a rational strategy to reverse this process to sensitize HNSCC to radiotherapy. PMID:25297633

  6. Targeting hedgehog signalling by arsenic trioxide reduces cell growth and induces apoptosis in rhabdomyosarcoma.

    PubMed

    Boehme, Karen A; Zaborski, Julian J; Riester, Rosa; Schweiss, Sabrina K; Hopp, Ulrike; Traub, Frank; Kluba, Torsten; Handgretinger, Rupert; Schleicher, Sabine B

    2016-02-01

    Rhabdomyosarcomas (RMS) are soft tissue tumours treated with a combination of surgery and chemotherapy. However, mortality rates remain high in case of recurrences and metastatic disease due to drug resistance and failure to undergo apoptosis. Therefore, innovative approaches targeting specific signalling pathways are urgently needed. We analysed the impact of different hedgehog (Hh) pathway inhibitors on growth and survival of six RMS cell lines using MTS assay, colony formation assay, 3D spheroid cultures, flow cytometry and western blotting. Especially the glioma-associated oncogene family (GLI) inhibitor arsenic trioxide (ATO) effectively reduced viability as well as clonal growth and induced cell death in RMS cell lines of embryonal, alveolar and sclerosing, spindle cell subtype, whereas normal skeletal muscle cells were hardly compromised by ATO. Combination of ATO with itraconazole potentiated the reduction of colony formation and spheroid size. These results show that ATO is a promising substance for treatment of relapsed and refractory RMS by directly targeting GLI transcription factors. The combination with itraconazole or other chemotherapeutic drugs has the opportunity to enforce the treatment efficiency of resistant and recurrent RMS.

  7. Hedgehog signaling mediates adaptive variation in a dynamic functional system in the cichlid feeding apparatus

    PubMed Central

    Hu, Yinan; Albertson, R. Craig

    2014-01-01

    Adaptive variation in the craniofacial skeleton is a key component of resource specialization and habitat divergence in vertebrates, but the proximate genetic mechanisms that underlie complex patterns of craniofacial variation are largely unknown. Here we demonstrate that the Hedgehog (Hh) signaling pathway mediates widespread variation across a complex functional system that affects the kinematics of lower jaw depression—the opercular four-bar linkage apparatus—among Lake Malawi cichlids. By using a combined quantitative trait locus mapping and population genetics approach, we show that allelic variation in the Hh receptor, ptch1, affects the development of distinct bony elements in the head that represent two of three movable links in this functional system. The evolutionarily derived allele is found in species that feed from the water column, and is associated with shifts in anatomy that translate to a four-bar system capable of faster jaw rotation. Alternatively, the ancestral allele is found in species that feed on attached algae, and is associated with the development of a four-bar system that predicts slower jaw movement. Experimental manipulation of the Hh pathway during cichlid development recapitulates functionally salient natural variation in craniofacial geometry. In all, these results significantly extend our understanding of the mechanisms that fine-tune the craniofacial skeletal complex during adaptation to new foraging niches. PMID:24912175

  8. Olfactomedin 4 deficiency promotes prostate neoplastic progression and is associated with upregulation of the hedgehog-signaling pathway

    PubMed Central

    Li, Hongzhen; Liu, Wenli; Chen, Weiping; Zhu, Jianqiong; Deng, Chu-Xia; Rodgers, Griffin P.

    2015-01-01

    Loss of olfactomedin 4 (OLFM4) gene expression is associated with the progression of human prostate cancer, but its role and the molecular mechanisms involved in this process have not been completely understood. In this study, we found that Olfm4-knockout mice developed prostatic intraepithelial neoplasia and prostatic adenocarcinoma. Importantly, we found that the hedgehog-signaling pathway was significantly upregulated in the Olfm4-knockout mouse model. We also found that restoration of OLFM4 in human prostate-cancer cells that lack OLFM4 expression significantly downregulated hedgehog signaling-pathway component expression. Furthermore, we demonstrated that the OLFM4 protein interacts with sonic hedgehog protein, as well as significantly inhibits GLI-reporter activity. Bioinformatic and immunohistochemistry analyses revealed that decreased OLFM4 and increased SHH expression was significantly associated with advanced human prostate cancer. Thus, olfactomedin 4 appears to play a critical role in regulating progression of prostate cancer, and has potential as a new biomarker for prostate cancer. PMID:26581960

  9. Processing by Convertases Is Required for Glypican-3-induced Inhibition of Hedgehog Signaling*

    PubMed Central

    Capurro, Mariana; Shi, Wen; Izumikawa, Tomomi; Kitagawa, Hiroshi; Filmus, Jorge

    2015-01-01

    Glypican-3 (GPC3) is one of the six members of the mammalian glypican family. We have previously reported that GPC3 inhibits Hedgehog (Hh) signaling by competing with Patched (Ptc) for Hh binding. We also showed that GPC3 binds with high affinity to Hh through its core protein, but that it does not interact with Ptc. Several members of the glypican family, including GPC3, are subjected to an endoproteolytic cleavage by the furin-like convertase family of endoproteases. Surprisingly, however, we have found that a mutant GPC3 that cannot be processed by convertases is as potent as wild-type GPC3 in stimulating Wnt activity in hepatocellular carcinoma cell lines and 293T cells and in promoting hepatocellular carcinoma growth. In this study, we show that processing by convertases is essential for GPC3-induced inhibition of Hh signaling. Moreover, we show that a convertase-resistant GPC3 stimulates Hh signaling by increasing the binding of this growth factor to Ptc. Consistent with this, we show that the convertase-resistant mutant binds to both Hh and Ptc through its heparan sulfate (HS) chains. Unexpectedly, we found that the mutant core protein does not bind to Hh. We also report that the convertase-resistant mutant GPC3 carries HS chains with a significantly higher degree of sulfation than those of wild-type GPC3. We propose that the structural changes generated by the lack of cleavage determine a change in the sulfation of the HS chains and that these hypersulfated chains mediate the interaction of the mutant GPC3 with Ptc. PMID:25653284

  10. Androgens regulate Hedgehog signalling and proliferation in androgen-dependent prostate cells.

    PubMed

    Sirab, Nanor; Terry, Stéphane; Giton, Frank; Caradec, Josselin; Chimingqi, Mihelaiti; Moutereau, Stéphane; Vacherot, Francis; de la Taille, Alexandre; Kouyoumdjian, Jean-Claude; Loric, Sylvain

    2012-09-15

    Prostate cancer (PCa) is androgen sensitive in its development and progression to metastatic disease. Hedgehog (Hh) pathway activation is important in the initiation and growth of various carcinomas including PCa. We and others have observed aberrations of Hh pathway during the progression of PCa to the castration-resistant state. The involvement of androgen signalling in Hh pathway activation, however, remains largely elusive. Here we investigate the direct role of androgen signalling on Hh pathway. We examined the effect of Dihydrosterone (DHT), antiandrogen, bicalutamide, and Hh pathway inhibitor, KAAD-cyclopamine in four human prostate cell lines (two cancerous: LNCaP, VCaP, and two normal: PNT2 and PNT2-ARm which harbours a mutant version of androgen receptor (AR) that is commonly found in LNCaP). Cell proliferation as well as Hh pathway members (SHH, IHH, DHH, GLI, PTCH) mRNA expression levels were assessed. We showed that KAAD-cyclopamine decreased cell proliferation of DHT-stimulated LNCaP, VCaP and PNT2-ARm cells. SHH expression was found to be downregulated by DHT in all AR posititve cells. The negative effect of DHT on SHH expression was counteracted when cells were treated by bicalutamide. Importantly, KAAD-cyclopamine treatment seemed to inhibit AR activity. Moreover, bicalutamide as well as KAAD-cyclopamine treatments induced GLI and PTCH expression in VCaP and PNT2-ARm. Our results suggest that Hh pathway activity can be regulated by androgen signalling. Specifically, we show that the DHT-induced inhibition of Hh pathway is AR dependent. The mutual interaction between these two pathways might be important in the regulation of cell proliferation in PCa.

  11. A Mutation in the Mouse Ttc26 Gene Leads to Impaired Hedgehog Signaling

    PubMed Central

    Swiderski, Ruth E.; Nakano, Yoko; Mullins, Robert F.; Seo, Seongjin; Bánfi, Botond

    2014-01-01

    The phenotype of the spontaneous mutant mouse hop-sterile (hop) is characterized by a hopping gait, polydactyly, hydrocephalus, and male sterility. Previous analyses of the hop mouse revealed a deficiency of inner dynein arms in motile cilia and a lack of sperm flagella, potentially accounting for the hydrocephalus and male sterility. The etiology of the other phenotypes and the location of the hop mutation remained unexplored. Here we show that the hop mutation is located in the Ttc26 gene and impairs Hedgehog (Hh) signaling. Expression analysis showed that this mutation led to dramatically reduced levels of the Ttc26 protein, and protein-protein interaction assays demonstrated that wild-type Ttc26 binds directly to the Ift46 subunit of Intraflagellar Transport (IFT) complex B. Although IFT is required for ciliogenesis, the Ttc26 defect did not result in a decrease in the number or length of primary cilia. Nevertheless, Hh signaling was reduced in the hop mouse, as revealed by impaired activation of Gli transcription factors in embryonic fibroblasts and abnormal patterning of the neural tube. Unlike the previously characterized mutations that affect IFT complex B, hop did not interfere with Hh-induced accumulation of Gli at the tip of the primary cilium, but rather with the subsequent dissociation of Gli from its negative regulator, Sufu. Our analysis of the hop mouse line provides novel insights into Hh signaling, demonstrating that Ttc26 is necessary for efficient coupling between the accumulation of Gli at the ciliary tip and its dissociation from Sufu. PMID:25340710

  12. Epigenetic deregulation of Ellis Van Creveld confers robust Hedgehog signaling in adult T-cell leukemia.

    PubMed

    Takahashi, Ryutaro; Yamagishi, Makoto; Nakano, Kazumi; Yamochi, Toshiko; Yamochi, Tadanori; Fujikawa, Dai; Nakashima, Makoto; Tanaka, Yuetsu; Uchimaru, Kaoru; Utsunomiya, Atae; Watanabe, Toshiki

    2014-09-01

    One of the hallmarks of cancer, global gene expression alteration, is closely associated with the development and malignant characteristics associated with adult T-cell leukemia (ATL) as well as other cancers. Here, we show that aberrant overexpression of the Ellis Van Creveld (EVC) family is responsible for cellular Hedgehog (HH) activation, which provides the pro-survival ability of ATL cells. Using microarray, quantitative RT-PCR and immunohistochemistry we have demonstrated that EVC is significantly upregulated in ATL and human T-cell leukemia virus type I (HTLV-1)-infected cells. Epigenetic marks, including histone H3 acetylation and Lys4 trimethylation, are specifically accumulated at the EVC locus in ATL samples. The HTLV-1 Tax participates in the coordination of EVC expression in an epigenetic fashion. The treatment of shRNA targeting EVC, as well as the transcription factors for HH signaling, diminishes the HH activation and leads to apoptotic death in ATL cell lines. We also showed that a HH signaling inhibitor, GANT61, induces strong apoptosis in the established ATL cell lines and patient-derived primary ATL cells. Therefore, our data indicate that HH activation is involved in the regulation of leukemic cell survival. The epigenetically deregulated EVC appears to play an important role for HH activation. The possible use of EVC as a specific cell marker and a novel drug target for HTLV-1-infected T-cells is implicated by these findings. The HH inhibitors are suggested as drug candidates for ATL therapy. Our findings also suggest chromatin rearrangement associated with active histone markers in ATL.

  13. Development of stratum intermedium and its role as a Sonic hedgehog-signaling structure during odontogenesis.

    PubMed

    Koyama, E; Wu, C; Shimo, T; Iwamoto, M; Ohmori, T; Kurisu, K; Ookura, T; Bashir, M M; Abrams, W R; Tucker, T; Pacifici, M

    2001-10-01

    Stratum intermedium is a transient and subtle epithelial structure closely associated with inner dental epithelium in tooth germs. Little is known about its development and roles. To facilitate analysis, we used bovine tooth germs, predicting that they may contain a more conspicuous stratum intermedium. Indeed, early bell stage bovine tooth germs already displayed an obvious stratum intermedium with a typical multilayered organization and flanking the enamel knot. Strikingly, with further development, the cuspally located stratum intermedium underwent thinning and involution, whereas a multilayered stratum intermedium formed at successive sites along the cusp-to-cervix axis of odontogenesis. In situ hybridization and immunohistochemistry showed that stratum intermedium produces the signaling molecule Sonic hedgehog (Shh). Maximal Shh expression was invariably seen in its thickest multilayered portions. Shh was also produced by inner dental epithelium; expression was not constant but varied with development and cytodifferentiation of ameloblasts along the cusp-to-cervix axis. Interestingly, maximal Shh expression in inner dental epithelium did not coincide with that in stratum intermedium. Both stratum intermedium and inner dental epithelium expressed the Shh receptor Patched2 (Ptch2), an indication of autocrine signaling loops. Shh protein, but not RNA, was present in underlying dental mesenchyme, probably resulting from gradual diffusion from epithelial layers and reflecting paracrine loops of action. To analyze the regulation of Shh expression, epithelial and mesenchymal layers were separated and maintained in organ culture. Shh expression decreased over time, but was maintained in unoperated specimens. Our data show for the first time that stratum intermedium is a highly regulated and Shh-expressing structure. Given its dynamic and apparently interactive properties, stratum intermedium may help orchestrate progression of odontogenesis from cusp to cervix.

  14. Hedgehog signaling mediates woven bone formation and vascularization during stress fracture healing.

    PubMed

    Kazmers, Nikolas H; McKenzie, Jennifer A; Shen, Tony S; Long, Fanxin; Silva, Matthew J

    2015-12-01

    Hedgehog (Hh) signaling is critical in developmental osteogenesis, and recent studies suggest it may also play a role in regulating osteogenic gene expression in the post-natal setting. However, there is a void of studies directly assessing the effect of Hh inhibition on post-natal osteogenesis. This study utilized a cyclic loading-induced ulnar stress fracture model to evaluate the hypothesis that Hh signaling contributes to osteogenesis and angiogenesis during stress fracture healing. Immediately prior to loading, adult rats were given GDC-0449 (Vismodegib - a selective Hh pathway inhibitor; 50mg/kg orally twice daily), or vehicle. Hh signaling was upregulated in response to stress fracture at 3 days (Ptch1, Gli1 expression), and was markedly inhibited by GDC-0449 at 1 day and 3 days in the loaded and non-loaded ulnae. GDC-0449 did not affect Hh ligand expression (Shh, Ihh, Dhh) at 1 day, but decreased Shh expression by 37% at 3 days. GDC-0449 decreased woven bone volume (-37%) and mineral density (-17%) at 7 days. Dynamic histomorphometry revealed that the 7 day callus was composed predominantly of woven bone in both groups. The observed reduction in woven bone occurred concomitantly with decreased expression of Alpl and Ibsp, but was not associated with differences in early cellular proliferation (as determined by callus PCNA staining at 3 days), osteoblastic differentiation (Osx expression at 1 day and 3 days), chondrogenic gene expression (Acan, Sox9, and Col2α1 expression at 1 day and 3 days), or bone resorption metrics (callus TRAP staining at 3 days, Rankl and Opg expression at 1 day and 3 days). To evaluate angiogenesis, vWF immunohistochemistry showed that GDC-0449 reduced fracture callus blood vessel density by 55% at 3 days, which was associated with increased Hif1α gene expression (+30%). Dynamic histomorphometric analysis demonstrated that GDC-0449 also inhibited lamellar bone formation. Lamellar bone analysis of the loaded limb (directly adjacent

  15. An Amphioxus Gli Gene Reveals Conservation of Midline Patterning and the Evolution of Hedgehog Signalling Diversity in Chordates

    PubMed Central

    Shimeld, Sebastian M.; van den Heuvel, Marcel; Dawber, Rebecca; Briscoe, James

    2007-01-01

    Background Hedgehog signalling, interpreted in receiving cells by Gli transcription factors, plays a central role in the development of vertebrate and Drosophila embryos. Many aspects of the signalling pathway are conserved between these lineages, however vertebrates have diverged in at least one key aspect: they have evolved multiple Gli genes encoding functionally-distinct proteins, increasing the complexity of the hedgehog-dependent transcriptional response. Amphioxus is one of the closest living relatives of the vertebrates, having split from the vertebrate lineage prior to the widespread gene duplication prominent in early vertebrate evolution. Principal Findings We show that amphioxus has a single Gli gene, which is deployed in tissues adjacent to sources of hedgehog signalling derived from the midline and anterior endoderm. This shows the duplication and divergence of the Gli gene family, and hence the origin of vertebrate Gli functional diversity, was specific to the vertebrate lineage. However we also show that the single amphioxus Gli gene produces two distinct transcripts encoding different proteins. We utilise three tests of Gli function to examine the transcription regulatory capacities of these different proteins, demonstrating one has activating activity similar to Gli2, while the other acts as a weak repressor, similar to Gli3. Conclusions These data show that vertebrates and amphioxus have evolved functionally-similar repertoires of Gli proteins using parallel molecular routes; vertebrates via gene duplication and divergence, and amphioxus via alternate splicing of a single gene. Our results demonstrate that similar functional complexity of intercellular signalling can be achieved via different evolutionary pathways. PMID:17848995

  16. Biodegradable polymeric micelles encapsulated JK184 suppress tumor growth through inhibiting Hedgehog signaling pathway

    NASA Astrophysics Data System (ADS)

    Zhang, Nannan; Liu, Shichang; Wang, Ning; Deng, Senyi; Song, Linjiang; Wu, Qinjie; Liu, Lei; Su, Weijun; Wei, Yuquan; Xie, Yongmei; Gong, Changyang

    2015-01-01

    JK184 can specially inhibit Gli in the Hedgehog (Hh) pathway, which showed great promise for cancer therapeutics. For developing aqueous formulation and improving anti-tumor activity of JK184, we prepared JK184 encapsulated MPEG-PCL micelles by the solid dispersion method without using surfactants or toxic organic solvents. The cytotoxicity and cellular uptake of JK184 micelles were both increased compared with the free drug. JK184 micelles induced more apoptosis and blocked proliferation of Panc-1 and BxPC-3 tumor cells. In addition, JK184 micelles exerted a sustained in vitro release behavior and had a stronger inhibitory effect on proliferation, migration and invasion of HUVECs than free JK184. Furthermore, JK184 micelles had stronger tumor growth inhibiting effects in subcutaneous Panc-1 and BxPC-3 tumor models. Histological analysis showed that JK184 micelles improved anti-tumor activity by inducing more apoptosis, decreasing microvessel density and reducing expression of CD31, Ki67, and VEGF in tumor tissues. JK184 micelles showed a stronger inhibition of Gli expression in Hh signaling, which played an important role in pancreatic carcinoma. Furthermore, circulation time of JK184 in blood was prolonged after entrapment in polymeric micelles. Our results suggested that JK184 micelles are a promising drug candidate for treating pancreatic tumors with a highly inhibitory effect on Hh activity.JK184 can specially inhibit Gli in the Hedgehog (Hh) pathway, which showed great promise for cancer therapeutics. For developing aqueous formulation and improving anti-tumor activity of JK184, we prepared JK184 encapsulated MPEG-PCL micelles by the solid dispersion method without using surfactants or toxic organic solvents. The cytotoxicity and cellular uptake of JK184 micelles were both increased compared with the free drug. JK184 micelles induced more apoptosis and blocked proliferation of Panc-1 and BxPC-3 tumor cells. In addition, JK184 micelles exerted a sustained in

  17. Quinolone-1-(2H)-ones as hedgehog signalling pathway inhibitors.

    PubMed

    Trinh, Trieu N; McLaughlin, Eileen A; Abdel-Hamid, Mohammed K; Gordon, Christopher P; Bernstein, Ilana R; Pye, Victoria; Cossar, Peter; Sakoff, Jennette A; McCluskey, Adam

    2016-07-14

    A series of quinolone-2-(1H)-ones derived from the Ugi-Knoevenagel three- and four-component reaction were prepared exhibiting low micromolar cytotoxicity against a panel of eight human cancer cell lines known to possess the Hedgehog Signalling Pathway (HSP) components, as well as the seminoma TCAM-2 cell line. A focused SAR study was conducted and revealed core characteristics of the quinolone-2-(1H)-ones required for cytotoxicity. These requirements included a C3-tethered indole moiety, an indole C5-methyl moiety, an aliphatic tail or an ester, as well as an additional aromatic moiety. Further investigation in the SAG-activated Shh-LIGHT2 cell line with the most active analogues: 2-(3-cyano-2-oxo-4-phenylquinolin-1(2H)-yl)-2-(1-methyl-1H-indol-3-yl)-N-(pentan-2-yl)acetamide (5), 2-(3-cyano-2-oxo-4-phenylquinolin-1(2H)-yl)-2-(5-methyl-1H-indol-3-yl)-N-(pentan-2-yl)acetamide (23) and ethyl (2-(3-cyano-2-oxo-4-phenylquinolin-1(2H)-yl)-2-(5-methyl-1H-indol-3-yl)acetyl)glycinate (24) demonstrated a down regulation of the HSP via a reduction in Gli expression, and in the mRNA levels of Ptch1 and Gli2. Analogues 5, 23 and 24 returned in cell inhibition values of 11.6, 2.9 and 3.1 μM, respectively, making this new HSP-inhibitor pharmacophore amongst the most potent non-Smo targeted inhibitors thus far reported. PMID:27272335

  18. Sonic Hedgehog Signaling Affected by Promoter Hypermethylation Induces Aberrant Gli2 Expression in Spina Bifida.

    PubMed

    Lu, Xiao-Lin; Wang, Li; Chang, Shao-Yan; Shangguan, Shao-Fang; Wang, Zhen; Wu, Li-Hua; Zou, Ji-Zhen; Xiao, Ping; Li, Rui; Bao, Yi-Hua; Qiu, Z-Y; Zhang, Ting

    2016-10-01

    GLI2 is a key mediator of the sonic hedgehog (Shh) signaling pathway and plays an important role in neural tube development during vertebrate embryogenesis; however, the role of gli2 in human folate-related neural tube defects remains unclear. In this study, we compared methylation status and polymorphisms of gli2 between spina bifida patients and a control group to explore the underlying mechanisms related to folate deficiency in spina bifida. No single nucleotide polymorphism was found to be significantly different between the two groups, although gli2 methylation levels were significantly increased in spina bifida samples, accompanied by aberrant GLI2 expression. Moreover, a prominent negative correlation was found between the folate level in brain tissue and the gli2 methylation status (r = -0.41, P = 0.014), and gli2 hypermethylation increased the risk of spina bifida with an odds ratio of 12.45 (95 % confidence interval: 2.71-57.22, P = 0.001). In addition, we established a cell model to illustrate the effect of gli2 expression and the accessibility of chromatin affected by methylation. High gli2 and gli1 mRNA expression was detected in 5-Aza-treated cells, while gli2 hypermethylation resulted in chromatin inaccessibility and a reduced association with nuclear proteins containing transcriptional factors. More meaningful to the pathway, the effect gene of the Shh pathway, gli1, was found to have a reduced level of expression along with a decreased expression of gli2 in our cell model. Aberrant high methylation resulted in the low expression of gli2 in spina bifida, which was affected by the change in chromatin status and the capacity of transcription factor binding. PMID:26446020

  19. Hedgehog signaling stimulates the formation of proliferating Müller glia-derived progenitor cells in the chick retina.

    PubMed

    Todd, Levi; Fischer, Andy J

    2015-08-01

    Müller glia can be stimulated to de-differentiate and become proliferating progenitor cells that regenerate neurons in the retina. The signaling pathways that regulate the formation of proliferating Müller glia-derived progenitor cells (MGPCs) are beginning to be revealed. The purpose of this study was to investigate whether Hedgehog (Hh) signaling influences the formation of MGPCs in the chick retina. We find that Hh signaling is increased in damaged retinas where MGPCs are known to form. Sonic Hedgehog (Shh) is normally present in the axons of ganglion cells, but becomes associated with Müller glia and MGPCs following retinal damage. Activation of Hh signaling with recombinant human SHH (rhShh) or smoothened agonist (SAG) increased levels of Ptch1, Gli1, Gli2, Gli3, Hes1 and Hes5, and stimulated the formation of proliferating MGPCs in damaged retinas. In undamaged retinas, SAG or rhShh had no apparent effect upon the Müller glia. However, SAG combined with FGF2 potentiated the formation of MGPCs, whereas SAG combined with IGF1 stimulated the nuclear migration of Müller glia, but not the formation of MGPCs. Conversely, inhibition of Hh signaling with KAAD-cyclopamine, Gli antagonists or antibody to Shh reduced numbers of proliferating MGPCs in damaged and FGF2-treated retinas. Hh signaling potentiates Pax6, Klf4 and cFos expression in Müller glia during the formation of MGPCs. We find that FGF2/MAPK signaling recruits Hh signaling into the signaling network that drives the formation of proliferating MGPCs. Our findings implicate Hh signaling as a key component of the network of signaling pathways that promote the de-differentiation of Müller glia and proliferation of MGPCs. PMID:26116667

  20. Hedgehog signaling from the primary cilium to the nucleus: an emerging picture of ciliary localization, trafficking and transduction

    PubMed Central

    Nozawa, Yoko Inès; Lin, Chuwen; Chuang, Pao-Tien

    2013-01-01

    The unexpected connection between cilia and signaling is one of the most exciting developments in cell biology in the past decade. In particular, the Hedgehog (Hh) signaling pathway relies on the primary cilium to regulate tissue patterning and homeostasis in vertebrates. A central question is how ciliary localization and trafficking of Hh pathway components lead to pathway activation and regulation. In this review, we discuss recent studies that reveal the roles of ciliary regulators, components and structures in controlling the movement and signaling of Hh players. These findings significantly increase our mechanistic understanding of how the primary cilium facilitates Hh signal transduction and form the basis for further investigations to define the function of cilia in other signaling processes. PMID:23725801

  1. Chondroprotective effects of palmatine on osteoarthritis in vivo and in vitro: A possible mechanism of inhibiting the Wnt/β-catenin and Hedgehog signaling pathways.

    PubMed

    Zhou, Xindie; Lin, Xiaolong; Xiong, Yan; Jiang, Lifeng; Li, Weijun; Li, Jin; Wu, Lidong

    2016-05-01

    The present study aimed to investigate the effect of palmatine (Pal) in a rabbit osteoarthritis (OA) model in vivo and rabbit interleukin-1β (IL-1β)-stimulated chondrocytes in vitro. Appropriate concentrations of Pal were identified by the MTT assay and used to preincubate IL-1β-induced chondrocytes, as well as an activator or inhibitor of Wnt and Hedgehog signaling pathways. Matrix metalloproteinase (MMP)-1, 3, and 13; tissue inhibitor of metalloproteinase (TIMP)-1; collagenase II; aggrecan; and the related molecules of the Wnt/β-catenin and Hedgehog signaling pathways were investigated. Protein expression was detected by Western blot analysis and messenger RNA (mRNA) expression was examined by PCR analysis. Pal (0.3 mL, 100 mg/L) was injected into rabbit knee joints and histological examination, immunohistochemistry, and Mankin scoring of the articular cartilage were performed. Pal (10-100 mg/L) had no effect on chondrocyte viability, decreased the expression of the MMPs, and increased the synthesis of TIMP-1whereas collagenase II and aggrecan were inhibited by IL-1β. When the activator (Licl) and inhibitor (DKK-1) of the Wnt/β-catenin signaling pathway as well as the inhibitor (cyclopamine) of the Hedgehog signaling pathway were added, the Wnt/β-catenin signaling pathway was less inhibited by Pal, and a similar inhibitory effect of cyclopamine on the Hedgehog signaling pathway was evident. Additionally, Pal enhanced the effect of cyclopamine. The histological examination, immunohistochemistry and Mankin scoring also demonstrated the protective effect of Pal, and the inhibition of the Wnt and Hedgehog signaling pathways by Pal. Pal may be useful in the treatment of OA, in which its effect is likely mediated via the Wnt/β-catenin and Hedgehog signaling pathways. PMID:26945831

  2. New Constitutively Active Phytochromes Exhibit Light-Independent Signaling Activity.

    PubMed

    Jeong, A-Reum; Lee, Si-Seok; Han, Yun-Jeong; Shin, Ah-Young; Baek, Ayoung; Ahn, Taeho; Kim, Min-Gon; Kim, Young Soon; Lee, Keun Woo; Nagatani, Akira; Kim, Jeong-Il

    2016-08-01

    Plant phytochromes are photoreceptors that mediate a variety of photomorphogenic responses. There are two spectral photoisomers, the red light-absorbing Pr and far-red light-absorbing Pfr forms, and the photoreversible transformation between the two forms is important for the functioning of phytochromes. In this study, we isolated a Tyr-268-to-Val mutant of Avena sativa phytochrome A (AsYVA) that displayed little photoconversion. Interestingly, transgenic plants of AsYVA showed light-independent phytochrome signaling with a constitutive photomorphogenic (cop) phenotype that is characterized by shortened hypocotyls and open cotyledons in the dark. In addition, the corresponding Tyr-303-to-Val mutant of Arabidopsis (Arabidopsis thaliana) phytochrome B (AtYVB) exhibited nuclear localization and interaction with phytochrome-interacting factor 3 (PIF3) independently of light, conferring a constitutive photomorphogenic development to its transgenic plants, which is comparable to the first constitutively active version of phytochrome B (YHB; Tyr-276-to-His mutant). We also found that chromophore ligation was required for the light-independent interaction of AtYVB with PIF3. Moreover, we demonstrated that AtYVB did not exhibit phytochrome B activity when it was localized in the cytosol by fusion with the nuclear export signal and that AsYVA exhibited the full activity of phytochrome A when localized in the nucleus by fusion with the nuclear localization signal. Furthermore, the corresponding Tyr-269-to-Val mutant of Arabidopsis phytochrome A (AtYVA) exhibited similar cop phenotypes in transgenic plants to AsYVA. Collectively, these results suggest that the conserved Tyr residues in the chromophore-binding pocket play an important role during the Pr-to-Pfr photoconversion of phytochromes, providing new constitutively active alleles of phytochromes by the Tyr-to-Val mutation. PMID:27325667

  3. The buccohypophyseal canal is an ancestral vertebrate trait maintained by modulation in sonic hedgehog signaling

    PubMed Central

    2013-01-01

    Background The pituitary gland is formed by the juxtaposition of two tissues: neuroectoderm arising from the basal diencephalon, and oral epithelium, which invaginates towards the central nervous system from the roof of the mouth. The oral invagination that reaches the brain from the mouth is referred to as Rathke’s pouch, with the tip forming the adenohypophysis and the stalk disappearing after the earliest stages of development. In tetrapods, formation of the cranial base establishes a definitive barrier between the pituitary and oral cavity; however, numerous extinct and extant vertebrate species retain an open buccohypophyseal canal in adulthood, a vestige of the stalk of Rathke’s pouch. Little is currently known about the formation and function of this structure. Here we have investigated molecular mechanisms driving the formation of the buccohypophyseal canal and their evolutionary significance. Results We show that Rathke’s pouch is located at a boundary region delineated by endoderm, neural crest-derived oral mesenchyme and the anterior limit of the notochord, using CD1, R26R-Sox17-Cre and R26R-Wnt1-Cre mouse lines. As revealed by synchrotron X-ray microtomography after iodine staining in mouse embryos, the pouch has a lobulated three-dimensional structure that embraces the descending diencephalon during pituitary formation. Polarisfl/fl; Wnt1-Cre, Ofd1-/- and Kif3a-/- primary cilia mouse mutants have abnormal sonic hedgehog (Shh) signaling and all present with malformations of the anterior pituitary gland and midline structures of the anterior cranial base. Changes in the expressions of Shh downstream genes are confirmed in Gas1-/- mice. From an evolutionary perspective, persistence of the buccohypophyseal canal is a basal character for all vertebrates and its maintenance in several groups is related to a specific morphology of the midline that can be related to modulation in Shh signaling. Conclusion These results provide insight into a poorly

  4. The Organocatalytic Approach to Enantiopure 2H- and 3H-Pyrroles: Inhibitors of the Hedgehog Signaling Pathway.

    PubMed

    Kötzner, Lisa; Leutzsch, Markus; Sievers, Sonja; Patil, Sumersing; Waldmann, Herbert; Zheng, Yiying; Thiel, Walter; List, Benjamin

    2016-06-27

    A divergent approach to enantioenriched 2H- and 3H-pyrroles catalyzed by a spirocyclic phosphoric acid is reported that makes use of a Fischer-type indolization and a [1,5]-alkyl shift. Catalyzed by the chiral phosphoric acid STRIP, good to excellent yields and enantioselectivities could be obtained. Remarkably, biological evaluation reveals one of these novel 2H-pyrroles to be a potent but nontoxic inhibitor of the Hedgehog signaling pathway by binding to the Smoothened protein. PMID:27239757

  5. Resveratrol inhibits epithelial-mesenchymal transition and renal fibrosis by antagonizing the hedgehog signaling pathway.

    PubMed

    Bai, Yongheng; Lu, Hong; Wu, Cunzao; Liang, Yong; Wang, Silu; Lin, Chengcheng; Chen, Bicheng; Xia, Peng

    2014-12-01

    Epithelial-to-mesenchymal transition (EMT), a biologic process in which tubular cells lose their epithelial phenotypes and acquire new characteristic features of mesenchymal properties, is increasingly recognized as an integral part of renal tissue fibrogenesis. Recent studies indicate that resveratrol, a botanical compound derived mainly from the skins of red grapes, may have anti-fibrotic effects in many tissues, but the potential molecular mechanism remains unknown. In the present study, we identified that resveratrol inhibits the induction of EMT and deposition of extracellular matrix (ECM) through antagonizing the hedgehog pathway in vitro and in vivo. In rats with unilateral ureteral obstruction (UUO), administration of resveratrol (20mg/kg/day) significantly reduced serum creatinine. Resveratrol also decreased expression of TGF-β1, and inhibited the phenotypic transition from epithelial cells to mesenchymal cells, and the deposition of ECM in UUO rats. In cultured renal tubular epithelial cells (NRK-52E), TGF-β1-induced EMT and ECM synthesis was abolished with the treatment of resveratrol. The induction of EMT was associated with the activation of the hedgehog pathway. Resveratrol treatment markedly inhibited the over-activity of the hedgehog pathway in the obstructed kidney and in TGF-β1-treated NRK-52E cells, resulted in reduction of cellular proliferation, EMT and ECM accumulation. Thus, these results suggest that resveratrol is able to inhibit EMT and fibrosis in vivo and in vitro through antagonizing the hedgehog pathway, and resveratrol may have therapeutic potential for patients with fibrotic kidney diseases.

  6. Zebrafish ift57, ift88, and ift172 intraflagellar transport mutants disrupt cilia but do not affect hedgehog signaling.

    PubMed

    Lunt, Shannon C; Haynes, Tony; Perkins, Brian D

    2009-07-01

    Cilia formation requires intraflagellar transport (IFT) proteins. Recent studies indicate that mammalian Hedgehog (Hh) signaling requires cilia. It is unclear, however, if the requirement for cilia and IFT proteins in Hh signaling represents a general rule for all vertebrates. Here we examine zebrafish ift57, ift88, and ift172 mutants and morphants for defects in Hh signaling. Although ift57 and ift88 mutants and morphants contained residual maternal protein, the cilia were disrupted. In contrast to previous genetic studies in mouse, mutations in zebrafish IFT genes did not affect the expression of Hh target genes in the neural tube and forebrain and had no quantitative effect on Hh target gene expression. Zebrafish IFT mutants also exhibited no dramatic changes in the craniofacial skeleton, somite formation, or motor neuron patterning. Thus, our data indicate the requirement for cilia in the Hh signal transduction pathway may not represent a universal mechanism in vertebrates.

  7. A local difference in Hedgehog signal transduction increases mechanical cell bond tension and biases cell intercalations along the Drosophila anteroposterior compartment boundary.

    PubMed

    Rudolf, Katrin; Umetsu, Daiki; Aliee, Maryam; Sui, Liyuan; Jülicher, Frank; Dahmann, Christian

    2015-11-15

    Tissue organization requires the interplay between biochemical signaling and cellular force generation. The formation of straight boundaries separating cells with different fates into compartments is important for growth and patterning during tissue development. In the developing Drosophila wing disc, maintenance of the straight anteroposterior (AP) compartment boundary involves a local increase in mechanical tension at cell bonds along the boundary. The biochemical signals that regulate mechanical tension along the AP boundary, however, remain unknown. Here, we show that a local difference in Hedgehog signal transduction activity between anterior and posterior cells is necessary and sufficient to increase mechanical tension along the AP boundary. This difference in Hedgehog signal transduction is also required to bias cell rearrangements during cell intercalations to keep the characteristic straight shape of the AP boundary. Moreover, severing cell bonds along the AP boundary does not reduce tension at neighboring bonds, implying that active mechanical tension is upregulated, cell bond by cell bond. Finally, differences in the expression of the homeodomain-containing protein Engrailed also contribute to the straight shape of the AP boundary, independently of Hedgehog signal transduction and without modulating cell bond tension. Our data reveal a novel link between local differences in Hedgehog signal transduction and a local increase in active mechanical tension of cell bonds that biases junctional rearrangements. The large-scale shape of the AP boundary thus emerges from biochemical signals inducing patterns of active tension on cell bonds.

  8. Regulation of Smoothened Phosphorylation and High-Level Hedgehog Signaling Activity by a Plasma Membrane Associated Kinase.

    PubMed

    Li, Shuangxi; Li, Shuang; Han, Yuhong; Tong, Chao; Wang, Bing; Chen, Yongbin; Jiang, Jin

    2016-06-01

    Hedgehog (Hh) signaling controls embryonic development and adult tissue homeostasis through the G protein coupled receptor (GPCR)-family protein Smoothened (Smo). Upon stimulation, Smo accumulates on the cell surface in Drosophila or primary cilia in vertebrates, which is thought to be essential for its activation and function, but the underlying mechanisms remain poorly understood. Here we show that Hh stimulates the binding of Smo to a plasma membrane-associated kinase Gilgamesh (Gish)/CK1γ and that Gish fine-tunes Hh pathway activity by phosphorylating a Ser/Thr cluster (CL-II) in the juxtamembrane region of Smo carboxyl-terminal intracellular tail (C-tail). We find that CL-II phosphorylation is promoted by protein kinase A (PKA)-mediated phosphorylation of Smo C-tail and depends on cell surface localization of both Gish and Smo. Consistent with CL-II being critical for high-threshold Hh target gene expression, its phosphorylation appears to require higher levels of Hh or longer exposure to the same level of Hh than PKA-site phosphorylation on Smo. Furthermore, we find that vertebrate CK1γ is localized at the primary cilium to promote Smo phosphorylation and Sonic hedgehog (Shh) pathway activation. Our study reveals a conserved mechanism whereby Hh induces a change in Smo subcellular localization to promote its association with and activation by a plasma membrane localized kinase, and provides new insight into how Hh morphogen progressively activates Smo. PMID:27280464

  9. Regulation of Smoothened Phosphorylation and High-Level Hedgehog Signaling Activity by a Plasma Membrane Associated Kinase

    PubMed Central

    Tong, Chao; Wang, Bing; Chen, Yongbin; Jiang, Jin

    2016-01-01

    Hedgehog (Hh) signaling controls embryonic development and adult tissue homeostasis through the G protein coupled receptor (GPCR)-family protein Smoothened (Smo). Upon stimulation, Smo accumulates on the cell surface in Drosophila or primary cilia in vertebrates, which is thought to be essential for its activation and function, but the underlying mechanisms remain poorly understood. Here we show that Hh stimulates the binding of Smo to a plasma membrane-associated kinase Gilgamesh (Gish)/CK1γ and that Gish fine-tunes Hh pathway activity by phosphorylating a Ser/Thr cluster (CL-II) in the juxtamembrane region of Smo carboxyl-terminal intracellular tail (C-tail). We find that CL-II phosphorylation is promoted by protein kinase A (PKA)-mediated phosphorylation of Smo C-tail and depends on cell surface localization of both Gish and Smo. Consistent with CL-II being critical for high-threshold Hh target gene expression, its phosphorylation appears to require higher levels of Hh or longer exposure to the same level of Hh than PKA-site phosphorylation on Smo. Furthermore, we find that vertebrate CK1γ is localized at the primary cilium to promote Smo phosphorylation and Sonic hedgehog (Shh) pathway activation. Our study reveals a conserved mechanism whereby Hh induces a change in Smo subcellular localization to promote its association with and activation by a plasma membrane localized kinase, and provides new insight into how Hh morphogen progressively activates Smo. PMID:27280464

  10. Indian Hedgehog signaling pathway members are associated with magnetic resonance imaging manifestations and pathological scores in lumbar facet joint osteoarthritis.

    PubMed

    Shuang, Feng; Zhou, Ying; Hou, Shu-Xun; Zhu, Jia-Liang; Liu, Yan; Zhang, Chun-Li; Tang, Jia-Guang

    2015-01-01

    Indian Hedgehog (HH) has been shown to be involved in osteoarthritis (OA) in articular joints, where there is evidence that Indian HH blockade could ameliorate OA. It seems to play a prominent role in development of the intervertebral disc (IVD) and in postnatal maintenance. There is little work on IHH in the IVD. Hence the aim of the current study was to investigate the role of Indian Hedgehog in the pathology of facet joint (FJ) OA. 24 patients diagnosed with lumbar intervertebral disk herniation or degenerative spinal stenosis were included. Preoperative magnetic resonance imaging (MRI) and Osteoarthritis Research Society International (OARSI) histopathology grading system was correlated to the mRNA levels of GLI1, PTCH1, and HHIP in the FJs. The Weishaupt grading and OARSI scores showed high positive correlation (r = 0.894) (P < 0.01). MRI Weishaupt grades showed positive correlation with GLI1 (r = 0.491), PTCH1 (r = 0.444), and HHIP (r = 0.654) mRNA levels (P < 0.05 in each case). OARSI scores were also positively correlated with GLI1 (r = 0. 646), PTCH1 (r = 0. 518), and HHIP (r = 0.762) mRNA levels (P < 0.01 in each case). Cumulatively our findings indicate that Indian HH signaling is increased in OA and is perhaps a key component in OA pathogenesis and progression. PMID:25992955

  11. Indian Hedgehog signaling pathway members are associated with magnetic resonance imaging manifestations and pathological scores in lumbar facet joint osteoarthritis.

    PubMed

    Shuang, Feng; Zhou, Ying; Hou, Shu-Xun; Zhu, Jia-Liang; Liu, Yan; Zhang, Chun-Li; Tang, Jia-Guang

    2015-01-01

    Indian Hedgehog (HH) has been shown to be involved in osteoarthritis (OA) in articular joints, where there is evidence that Indian HH blockade could ameliorate OA. It seems to play a prominent role in development of the intervertebral disc (IVD) and in postnatal maintenance. There is little work on IHH in the IVD. Hence the aim of the current study was to investigate the role of Indian Hedgehog in the pathology of facet joint (FJ) OA. 24 patients diagnosed with lumbar intervertebral disk herniation or degenerative spinal stenosis were included. Preoperative magnetic resonance imaging (MRI) and Osteoarthritis Research Society International (OARSI) histopathology grading system was correlated to the mRNA levels of GLI1, PTCH1, and HHIP in the FJs. The Weishaupt grading and OARSI scores showed high positive correlation (r = 0.894) (P < 0.01). MRI Weishaupt grades showed positive correlation with GLI1 (r = 0.491), PTCH1 (r = 0.444), and HHIP (r = 0.654) mRNA levels (P < 0.05 in each case). OARSI scores were also positively correlated with GLI1 (r = 0. 646), PTCH1 (r = 0. 518), and HHIP (r = 0.762) mRNA levels (P < 0.01 in each case). Cumulatively our findings indicate that Indian HH signaling is increased in OA and is perhaps a key component in OA pathogenesis and progression.

  12. Small hepatocyte-like progenitor cells may be a Hedgehog signaling pathway-controlled subgroup of liver stem cells

    PubMed Central

    Wang, Zhibin; Li, Wei; Li, Chun; Yang, Yang; Li, Wang; Zhang, Liying; Sun, Shumei; Li, Junxiang; Cai, Yidong

    2016-01-01

    The present study aimed to investigate the expression levels of components of the Hedgehog signaling pathway (HH) during the proliferation of a liver stem cell subgroup, namely small hepatocyte-like progenitor cells (SHPCs). Retrorsine-treated Fisher 344 rats underwent a partial hepatectomy (PH) to induce the proliferation of SHPCs, after which reverse transcription-polymerase chain reaction (PCR), quantitative PCR, immunohistochemistry and western blot analysis were performed to analyze the expression of various components of the HH in primary SHPCs at different times points post-PH. A number of components of the HH, including Indian hedgehog (IHH), patched (PTCH), smoothened and glioma-associated oncogene (GLI)1, 2 and 3, were continuously expressed and showed dynamic changes in proliferating SHPCs. In addition, the expression levels of IHH, PTCH and GLI1 were significantly different as compared with those of the control group at the same time point, and there were significant differences among the various time points in the experimental group (P<0.01). Furthermore, there was an association between the postoperative day and expression levels of HH components in the retrorsine-treated group. An immunohistochemical analysis demonstrated that PTCH was also expressed at the protein level. In conclusion, the results of the present study suggested that the HH was continuously activated during the proliferation of SHPCs, thus indicating that SHPCs may be a subgroup of stem cells that are regulated by the HH. PMID:27703504

  13. Indian Hedgehog signaling pathway members are associated with magnetic resonance imaging manifestations and pathological scores in lumbar facet joint osteoarthritis

    NASA Astrophysics Data System (ADS)

    Shuang, Feng; Zhou, Ying; Hou, Shu-Xun; Zhu, Jia-Liang; Liu, Yan; Zhang, Chun-Li; Tang, Jia-Guang

    2015-05-01

    Indian Hedgehog (HH) has been shown to be involved in osteoarthritis (OA) in articular joints, where there is evidence that Indian HH blockade could ameliorate OA. It seems to play a prominent role in development of the intervertebral disc (IVD) and in postnatal maintenance. There is little work on IHH in the IVD. Hence the aim of the current study was to investigate the role of Indian Hedgehog in the pathology of facet joint (FJ) OA. 24 patients diagnosed with lumbar intervertebral disk herniation or degenerative spinal stenosis were included. Preoperative magnetic resonance imaging (MRI) and Osteoarthritis Research Society International (OARSI) histopathology grading system was correlated to the mRNA levels of GLI1, PTCH1, and HHIP in the FJs. The Weishaupt grading and OARSI scores showed high positive correlation (r = 0.894) (P < 0.01). MRI Weishaupt grades showed positive correlation with GLI1 (r = 0.491), PTCH1 (r = 0.444), and HHIP (r = 0.654) mRNA levels (P < 0.05 in each case). OARSI scores were also positively correlated with GLI1 (r = 0. 646), PTCH1 (r = 0. 518), and HHIP (r = 0.762) mRNA levels (P < 0.01 in each case). Cumulatively our findings indicate that Indian HH signaling is increased in OA and is perhaps a key component in OA pathogenesis and progression.

  14. Repression of Hedgehog signalling is required for the acquisition of dorsolateral cell fates in the zebrafish otic vesicle

    PubMed Central

    Hammond, Katherine L.; van Eeden, Fredericus J. M.; Whitfield, Tanya T.

    2010-01-01

    In zebrafish, Hedgehog (Hh) signalling from ventral midline structures is necessary and sufficient to specify posterior otic identity. Loss of Hh signalling gives rise to mirror symmetric ears with double anterior character, whereas severe upregulation of Hh signalling leads to double posterior ears. By contrast, in mouse and chick, Hh is predominantly required for dorsoventral otic patterning. Whereas a loss of Hh function in zebrafish does not affect dorsoventral and mediolateral otic patterning, we now show that a gain of Hh signalling activity causes ventromedial otic territories to expand at the expense of dorsolateral domains. In a panel of lines carrying mutations in Hh inhibitor genes, Hh pathway activity is increased throughout the embryo, and dorsolateral otic structures are lost or reduced. Even a modest increase in Hh signalling has consequences for patterning the ear. In ptc1–/– and ptc2–/– mutant embryos, in which Hh signalling is maximal throughout the embryo, the inner ear is severely ventralised and medialised, in addition to displaying the previously reported double posterior character. Transplantation experiments suggest that the effects of the loss of Hh pathway inhibition on the ear are mediated directly. These new data suggest that Hh signalling must be kept tightly repressed for the correct acquisition of dorsolateral cell fates in the zebrafish otic vesicle, revealing distinct similarities between the roles of Hh signalling in zebrafish and amniote inner ear patterning. PMID:20223756

  15. Hedgehog signaling is required for cranial neural crest morphogenesis and chondrogenesis at the midline in the zebrafish skull.

    PubMed

    Wada, Naoyuki; Javidan, Yashar; Nelson, Sarah; Carney, Thomas J; Kelsh, Robert N; Schilling, Thomas F

    2005-09-01

    Neural crest cells that form the vertebrate head skeleton migrate and interact with surrounding tissues to shape the skull, and defects in these processes underlie many human craniofacial syndromes. Signals at the midline play a crucial role in the development of the anterior neurocranium, which forms the ventral braincase and palate, and here we explore the role of Hedgehog (Hh) signaling in this process. Using sox10:egfp transgenics to follow neural crest cell movements in the living embryo, and vital dye labeling to generate a fate map, we show that distinct populations of neural crest form the two main cartilage elements of the larval anterior neurocranium: the paired trabeculae and the midline ethmoid. By analyzing zebrafish mutants that disrupt sonic hedgehog (shh) expression, we demonstrate that shh is required to specify the movements of progenitors of these elements at the midline, and to induce them to form cartilage. Treatments with cyclopamine, to block Hh signaling at different stages, suggest that although requirements in morphogenesis occur during neural crest migration beneath the brain, requirements in chondrogenesis occur later, as cells form separate trabecular and ethmoid condensations. Cell transplantations indicate that these also reflect different sources of Shh, one from the ventral neural tube that controls trabecular morphogenesis and one from the oral ectoderm that promotes chondrogenesis. Our results suggest a novel role for Shh in the movements of neural crest cells at the midline, as well as in their differentiation into cartilage, and help to explain why both skeletal fusions and palatal clefting are associated with the loss of Hh signaling in holoprosencephalic humans.

  16. Constitutive and ligand-induced EGFR signaling triggers distinct and mutually exclusive downstream signaling networks

    PubMed Central

    Chakraborty, Sharmistha; Li, Li; Puliyappadamba, VineshkumarThidil; Guo, Gao; Hatanpaa, Kimmo J.; Mickey, Bruce; Souza, Rhonda F.; Vo, Peggy; Herz, Joachim; Chen, Mei-Ru; Boothman, David A.; Pandita, Tej K.; Wang, David H.; Sen, Ganes C.; Habib, Amyn A.

    2014-01-01

    EGFR overexpression plays an important oncogenic role in cancer. Regular EGFR protein levels are increased in cancer cells and the receptor then becomes constitutively active. However, downstream signals generated by constitutively activated EGFR are unknown. Here we report that the overexpressed EGFR oscillates between two distinct and mutually exclusive modes of signaling. Constitutive or non-canonical EGFR signaling activates the transcription factor IRF3 leading to expression of IFI27, IFIT1, and TRAIL. Ligand-mediated activation of EGFR switches off IRF3 dependent transcription, activates canonical ERK and Akt signals, and confers sensitivity to chemotherapy and virus-induced cell death. Mechanistically, the distinct downstream signals result from a switch of EGFR associated proteins. EGFR constitutively complexes with IRF3 and TBK1 leading to TBK1 and IRF3 phosphorylation. Addition of EGF dissociates TBK1, IRF3, and EGFR leading to a loss of IRF3 activity, Shc-EGFR association and ERK activation. Finally, we provide evidence for non-canonical EGFR signaling in glioblastoma. PMID:25503978

  17. The G protein Gαs acts as a tumor suppressor in sonic hedgehog signaling-driven tumorigenesis.

    PubMed

    Rao, Rohit; Salloum, Ralph; Xin, Mei; Lu, Q Richard

    2016-05-18

    G protein-coupled receptors (GPCRs) are critical players in tumor growth and progression. The redundant roles of GPCRs in tumor development confound effective treatment; therefore, targeting a single common signaling component downstream of these receptors may be efficacious. GPCRs transmit signals through heterotrimeric G proteins composed of Gα and Gβγ subunits. Hyperactive Gαs signaling can mediate tumor progression in some tissues; however, recent work in medulloblastoma and basal cell carcinoma revealed that Gαs can also function as a tumor suppressor in neoplasms derived from ectoderm cells including neural and epidermal stem/progenitor cells. In these stem-cell compartments, signaling through Gαs suppresses self-renewal by inhibiting the Sonic Hedgehog (SHH) and Hippo pathways. The loss of GNAS, which encodes Gαs, leads to activation of these pathways, over-proliferation of progenitor cells, and tumor formation. Gαs activates the cAMP-dependent protein kinase A (PKA) signaling pathway and inhibits activation of SHH effectors Smoothened-Gli. In addition, Gαs-cAMP-PKA activation negatively regulates the Hippo pathway by blocking the NF2-LATS1/2-Yap signaling. In this review, we will address the novel function of the signaling network regulated by Gαs in suppression of SHH-driven tumorigenesis and the therapeutic approaches that can be envisioned to harness this pathway to inhibit tumor growth and progression. PMID:27052725

  18. Distinct Sonic Hedgehog signaling dynamics specify floor plate and ventral neuronal progenitors in the vertebrate neural tube.

    PubMed

    Ribes, Vanessa; Balaskas, Nikolaos; Sasai, Noriaki; Cruz, Catarina; Dessaud, Eric; Cayuso, Jordi; Tozer, Samuel; Yang, Lin Lin; Novitch, Ben; Marti, Elisa; Briscoe, James

    2010-06-01

    The secreted ligand Sonic Hedgehog (Shh) organizes the pattern of cellular differentiation in the ventral neural tube. For the five neuronal subtypes, increasing levels and durations of Shh signaling direct progenitors to progressively more ventral identities. Here we demonstrate that this mode of action is not applicable to the generation of the most ventral cell type, the nonneuronal floor plate (FP). In chick and mouse embryos, FP specification involves a biphasic response to Shh signaling that controls the dynamic expression of key transcription factors. During gastrulation and early somitogenesis, FP induction depends on high levels of Shh signaling. Subsequently, however, prospective FP cells become refractory to Shh signaling, and this is a prerequisite for the elaboration of their identity. This prompts a revision to the model of graded Shh signaling in the neural tube, and provides insight into how the dynamics of morphogen signaling are deployed to extend the patterning capacity of a single ligand. In addition, we provide evidence supporting a common scheme for FP specification by Shh signaling that reconciles mechanisms of FP development in teleosts and amniotes.

  19. The zebrafish-secreted matrix protein you/scube2 is implicated in long-range regulation of hedgehog signaling.

    PubMed

    Kawakami, Atsushi; Nojima, Yasuhiro; Toyoda, Atsushi; Takahoko, Mikako; Satoh, Miki; Tanaka, Hideomi; Wada, Hironori; Masai, Ichiro; Terasaki, Harumi; Sakaki, Yoshiyuki; Takeda, Hiroyuki; Okamoto, Hitoshi

    2005-03-01

    The Hedgehog (Hh) signal plays a pivotal role in induction of ventral neuronal and muscle cell types around the midline during vertebrate development [1]. We report that the gene disrupted in zebrafish you mutants, in which Hh signaling is impaired, encodes the secreted matrix protein Scube2. Consistently, epistasis analyses suggested that Scube2 functions upstream of Hh ligands or through a parallel pathway. In addition, overexpression analyses suggested that Scube2 is an essential, but a permissive, mediator of Hh signaling in zebrafish embryos. Surprisingly, the you gene is expressed in the dorsal neural tube, raising the possibility that Scube2 could indirectly act via a long-range regulator of Hh signaling. The dorsal Bmps have a long-range and opposing influence on Hh signaling [2-5]. We show that neural plate patterning is affected in you mutants in a way that is consistent with the aberrant long-range action of a Bmp-dependent signal. We further show that Bmp activity can be attenuated by the coexpression of Scube2. Our data support the idea that Scube2 can modulate the long-range action of Bmp-dependent signaling in the neural tube and somites.

  20. p63 Sustains self-renewal of mammary cancer stem cells through regulation of Sonic Hedgehog signaling.

    PubMed

    Memmi, Elisa Maria; Sanarico, Anna Giulia; Giacobbe, Arianna; Peschiaroli, Angelo; Frezza, Valentina; Cicalese, Angelo; Pisati, Federica; Tosoni, Daniela; Zhou, Huiqing; Tonon, Giovanni; Antonov, Alexey; Melino, Gerry; Pelicci, Pier Giuseppe; Bernassola, Francesca

    2015-03-17

    The predominant p63 isoform, ΔNp63, is a master regulator of normal epithelial stem cell (SC) maintenance. However, in vivo evidence of the regulation of cancer stem cell (CSC) properties by p63 is still limited. Here, we exploit the transgenic MMTV-ErbB2 (v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2) mouse model of carcinogenesis to dissect the role of p63 in the regulation of mammary CSC self-renewal and breast tumorigenesis. ErbB2 tumor cells enriched for SC-like properties display increased levels of ΔNp63 expression compared with normal mammary progenitors. Down-regulation of p63 in ErbB2 mammospheres markedly restricts self-renewal and expansion of CSCs, and this action is fully independent of p53. Furthermore, transplantation of ErbB2 progenitors expressing shRNAs against p63 into the mammary fat pads of syngeneic mice delays tumor growth in vivo. p63 knockdown in ErbB2 progenitors diminishes the expression of genes encoding components of the Sonic Hedgehog (Hh) signaling pathway, a driver of mammary SC self-renewal. Remarkably, p63 regulates the expression of Sonic Hedgehog (Shh), GLI family zinc finger 2 (Gli2), and Patched1 (Ptch1) genes by directly binding to their gene regulatory regions, and eventually contributes to pathway activation. Collectively, these studies highlight the importance of p63 in maintaining the self-renewal potential of mammary CSCs via a positive modulation of the Hh signaling pathway. PMID:25739959

  1. Zebrafish blowout provides genetic evidence for Patched1 mediated negative regulation of Hedgehog signaling within the proximal optic vesicle of the vertebrate eye

    PubMed Central

    Lee, Jiwoon; Willer, Jason R.; Willer, Gregory B.; Smith, Kierann; Gregg, Ronald G.; Gross, Jeffrey M.

    2008-01-01

    In this study we have characterized the ocular defects in the recessive zebrafish mutant blowout that presents with a variably penetrant coloboma phenotype. blowout mutants develop unilateral or bilateral colobomas and as a result, the retina and retinal pigmented epithelium are not contained within the optic cup. Colobomas result from defects in optic stalk morphogenesis whereby the optic stalk extends into the retina and impedes the lateral edges of the choroid fissure from meeting and fusing. The expression domain of the proximal optic vesicle marker pax2a is expanded in blowout at the expense of the distal optic vesicle marker pax6, suggesting that the initial patterning of the optic vesicle into proximal and distal territories is disrupted in blowout. Later aspects of distal optic cup formation (i.e. retina development) are normal in blowout mutants, however. Positional cloning of blowout identified a nonsense mutation in patched1, a negative regulator of the Hedgehog pathway, as the underlying cause of the blowout phenotype. Expanded domains of expression of the Hedgehog target genes patched1 and patched2 were observed in blowout, consistent with a loss of Patched1 function and upregulation of Hedgehog pathway activity. Moreover, colobomas in blowout could be suppressed by pharmacologically inhibiting the Hedgehog pathway with cyclopamine, and maximal rescue occurred when embryos were exposed to cyclopamine between 5.5 and 13 hours post fertilization. These observations highlight the critical role that Hedgehog pathway activity plays in mediating patterning of the proximal/distal axis of the optic vesicle during the early phases of eye development and they provide genetic confirmation for the integral role that patched1-mediated negative regulation of Hedgehog signaling plays during vertebrate eye development. PMID:18479681

  2. MicroRNA125b-mediated Hedgehog signaling influences liver regeneration by chorionic plate-derived mesenchymal stem cells.

    PubMed

    Hyun, Jeongeun; Wang, Sihyung; Kim, Jieun; Kim, Gi Jin; Jung, Youngmi

    2015-09-15

    Although chorionic plate-derived mesenchymal stem cells (CP-MSCs) were shown to promote liver regeneration, the mechanisms underlying the effect remain unclear. Hedgehog (Hh) signaling orchestrates tissue reconstruction in damaged liver. MSCs release microRNAs mediating various cellular responses. Hence, we hypothesized that microRNAs from CP-MSCs regulated Hh signaling, which influenced liver regeneration. Livers were obtained from carbon tetrachloride (CCl4)-treated rats transplanted with human CP-MSCs (Tx) or saline (non-Tx). Sonic Hh, one of Hh ligands, increased in CCl4-treated liver, whereas it decreased in CP-MSC-treated liver with CCl4. The expression of Hh-target genes was significantly downregulated in the Tx. Reduced expansion of progenitors and regressed fibrosis were observed in the liver of the Tx rats. CP-MSCs suppressed the expression of Hh and profibrotic genes in co-cultured LX2 (human hepatic stellate cell) with CP-MSCs. MicroRNA-125b targeting smo was retained in exosomes of CP-MSCs. CP-MSCs with microRNA-125b inhibitor failed to attenuate the expression of Hh signaling and profibrotic genes in the activated HSCs. Therefore, these results demonstrated that microRNA-125b from CP-MSCs suppressed the activation of Hh signaling, which promoted the reduced fibrosis, suggesting that microRNA-mediated regulation of Hh signaling contributed to liver regeneration by CP-MSCs.

  3. Foxj1 regulates floor plate cilia architecture and modifies the response of cells to sonic hedgehog signalling

    PubMed Central

    Cruz, Catarina; Ribes, Vanessa; Kutejova, Eva; Cayuso, Jordi; Lawson, Victoria; Norris, Dominic; Stevens, Jonathan; Davey, Megan; Blight, Ken; Bangs, Fiona; Mynett, Anita; Hirst, Elizabeth; Chung, Rachel; Balaskas, Nikolaos; Brody, Steven L.; Marti, Elisa; Briscoe, James

    2010-01-01

    Sonic hedgehog signalling is essential for the embryonic development of many tissues including the central nervous system, where it controls the pattern of cellular differentiation. A genome-wide screen of neural progenitor cells to evaluate the Shh signalling-regulated transcriptome identified the forkhead transcription factor Foxj1. In both chick and mouse Foxj1 is expressed in the ventral midline of the neural tube in cells that make up the floor plate. Consistent with the role of Foxj1 in the formation of long motile cilia, floor plate cells produce cilia that are longer than the primary cilia found elsewhere in the neural tube, and forced expression of Foxj1 in neuroepithelial cells is sufficient to increase cilia length. In addition, the expression of Foxj1 in the neural tube and in an Shh-responsive cell line attenuates intracellular signalling by decreasing the activity of Gli proteins, the transcriptional mediators of Shh signalling. We show that this function of Foxj1 depends on cilia. Nevertheless, floor plate identity and ciliogenesis are unaffected in mouse embryos lacking Foxj1 and we provide evidence that additional transcription factors expressed in the floor plate share overlapping functions with Foxj1. Together, these findings identify a novel mechanism that modifies the cellular response to Shh signalling and reveal morphological and functional features of the amniote floor plate that distinguish these cells from the rest of the neuroepithelium. PMID:21098568

  4. Aldehyde dehydrogenase 1A1 stabilizes transcription factor Gli2 and enhances the activity of Hedgehog signaling in hepatocellular cancer.

    PubMed

    Yan, Zhengwei; Xu, Liyao; Zhang, Junyan; Lu, Quqin; Luo, Shiwen; Xu, Linlin

    2016-03-18

    The Gli transcription factors are primary transcriptional regulators that mediate the activation of Hedgehog (Hh) signaling. Recent studies have revealed that Gli proteins are also regulated transcriptionally and post-translationally through noncanonical mechanisms, independent of Hh signaling. However, the precise mechanisms involved in the regulation of Gli proteins remain unclear. Using a differential mass-spectrometry approach, we found that aldehyde dehydrogenase 1A1 (ALDH1A1) is associated with transcription factor Gli2. Overexpression of ALDH1A1 increased Gli2 protein levels; in contrast, ALDH1A1 depletion facilitated Gli2 degradation. In addition, Gli2 mRNA expression was not affected by ectopic expression of ALDH1A1, indicating the role of ALDH1A1 in the stabilization of Gli2. Further investigation showed that ALDH1A1 prolonged the stability of Gli2 protein in a catalytic-independent manner. Finally, we showed that overexpression of ALDH1A1 activated the Hh signaling pathway and promoted cell growth, migration and invasion in hepatocellular cancer cells. Together, these results illustrate regulatory roles of ALDH1A1 in the activation of the Hh signaling pathway and highlight a novel mechanism for the aberrant activation of the Hh signaling pathway in hepatocellular cancer cells. PMID:26896768

  5. Regulation of Sufu activity by p66β and Mycbp provides new insight into vertebrate Hedgehog signaling

    PubMed Central

    Lin, Chuwen; Yao, Erica; Wang, Kevin; Nozawa, Yoko; Shimizu, Hirohito; Johnson, Jeffrey R.; Chen, Jau-Nian; Krogan, Nevan J.

    2014-01-01

    Control of Gli function by Suppressor of Fused (Sufu), a major negative regulator, is a key step in mammalian Hedgehog (Hh) signaling, but how this is achieved in the nucleus is unknown. We found that Hh signaling results in reduced Sufu protein levels and Sufu dissociation from Gli proteins in the nucleus, highlighting critical functions of Sufu in the nucleus. Through a proteomic approach, we identified several Sufu-interacting proteins, including p66β (a member of the NuRD [nucleosome remodeling and histone deacetylase] repressor complex) and Mycbp (a Myc-binding protein). p66β negatively and Mycbp positively regulate Hh signaling in cell-based assays and zebrafish. They function downstream from the membrane receptors, Patched and Smoothened, and the primary cilium. Sufu, p66β, Mycbp, and Gli are also detected on the promoters of Hh targets in a dynamic manner. Our results support a new model of Hh signaling in the nucleus. Sufu recruits p66β to block Gli-mediated Hh target gene expression. Meanwhile, Mycbp forms a complex with Gli and Sufu without Hh stimulation but remains inactive. Hh pathway activation leads to dissociation of Sufu/p66β from Gli, enabling Mycbp to promote Gli protein activity and Hh target gene expression. These studies provide novel insight into how Sufu controls Hh signaling in the nucleus. PMID:25403183

  6. A Recurrent Mosaic Mutation in SMO, Encoding the Hedgehog Signal Transducer Smoothened, Is the Major Cause of Curry-Jones Syndrome.

    PubMed

    Twigg, Stephen R F; Hufnagel, Robert B; Miller, Kerry A; Zhou, Yan; McGowan, Simon J; Taylor, John; Craft, Jude; Taylor, Jenny C; Santoro, Stephanie L; Huang, Taosheng; Hopkin, Robert J; Brady, Angela F; Clayton-Smith, Jill; Clericuzio, Carol L; Grange, Dorothy K; Groesser, Leopold; Hafner, Christian; Horn, Denise; Temple, I Karen; Dobyns, William B; Curry, Cynthia J; Jones, Marilyn C; Wilkie, Andrew O M

    2016-06-01

    Curry-Jones syndrome (CJS) is a multisystem disorder characterized by patchy skin lesions, polysyndactyly, diverse cerebral malformations, unicoronal craniosynostosis, iris colobomas, microphthalmia, and intestinal malrotation with myofibromas or hamartomas. Cerebellar medulloblastoma has been described in a single affected individual; in another, biopsy of skin lesions showed features of trichoblastoma. The combination of asymmetric clinical features, patchy skin manifestations, and neoplastic association previously led to the suggestion that this could be a mosaic condition, possibly involving hedgehog (Hh) signaling. Here, we show that CJS is caused by recurrent somatic mosaicism for a nonsynonymous variant in SMO (c.1234C>T [p.Leu412Phe]), encoding smoothened (SMO), a G-protein-coupled receptor that transduces Hh signaling. We identified eight mutation-positive individuals (two of whom had not been reported previously) with highly similar phenotypes and demonstrated varying amounts of the mutant allele in different tissues. We present detailed findings from brain MRI in three mutation-positive individuals. Somatic SMO mutations that result in constitutive activation have been described in several tumors, including medulloblastoma, ameloblastoma, and basal cell carcinoma. Strikingly, the most common of these mutations is the identical nonsynonymous variant encoding p.Leu412Phe. Furthermore, this substitution has been shown to activate SMO in the absence of Hh signaling, providing an explanation for tumor development in CJS. This raises therapeutic possibilities for using recently generated Hh-pathway inhibitors. In summary, our work uncovers the major genetic cause of CJS and illustrates strategies for gene discovery in the context of low-level tissue-specific somatic mosaicism. PMID:27236920

  7. Augmented Indian hedgehog signaling in cranial neural crest cells leads to craniofacial abnormalities and dysplastic temporomandibular joint in mice

    PubMed Central

    Yang, Ling; Gu, Shuping; Ye, Wenduo; Song, Yingnan; Chen, YiPing

    2016-01-01

    Extensive studies have pinpointed the crucial role of Indian hedgehog (Ihh) signaling in the development of the appendicular skeleton and the essential function of Ihh in the formation of the temporomandibular joint (TMJ). In this study, we have investigated the effect of augmented Ihh signaling in TMJ development. We took a transgenic gain-of-function approach by overexpressing Ihh in the cranial neural crest (CNC) cells using a conditional Ihh transgenic allele and the Wnt1-Cre allele. We found that Wnt1-Cre-mediated tissue-specific overexpression of Ihh in the CNC lineage caused severe craniofacial abnormalities, including cleft lip/palate, encephalocele, anophthalmos, micrognathia, and defective TMJ development. In the mutant TMJ, the glenoid fossa was completely absent, whereas the condyle and the articular disc appeared relatively normal with slightly delayed chondrocyte differentiation. Our findings thus demonstrate that augmented Ihh signaling is detrimental to craniofacial development, and that finely tuned Ihh signaling is critical for TMJ formation. Our results also provide additional evidence that the development of the condyle and articular disc is independent of the glenoid fossa. PMID:26553654

  8. Inhibition of the Nuclear Import of Cubitus Interruptus by Roadkill in the Presence of Strong Hedgehog Signal

    PubMed Central

    Seong, Ki-Hyeon; Akimaru, Hiroshi; Dai, Ping; Nomura, Teruaki; Okada, Masahiro; Ishii, Shunsuke

    2010-01-01

    Hedgehog (Hh) signalling plays an important role in various developmental processes by activating the Cubitus interruptus (Ci)/Glioblastoma (Gli) family of transcription factors. In the process of proper pattern formation, Ci activity is regulated by multiple mechanisms, including processing, trafficking, and degradation. However, it remains elusive how Ci distinctly recognizes the strong and moderate Hh signals. Roadkill (Rdx) induces Ci degradation in the anterior region of the Drosophila wing disc. Here, we report that Rdx inhibited Ci activity by two different mechanisms. In the region abutting the anterior/posterior boundary, which receives strong Hh signal, Rdx inhibited the nuclear import of Ci by releasing importin α3 from Ci. In this region, Rdx negatively regulated the expression of transcription factor Knot/Collier. In farther anterior regions receiving moderate levels of Hh signal, Rdx induced Ci degradation, as reported previously. Thus, two different mechanisms by which Rdx negatively regulates Ci may play an important role in the fine-tuning of Hh responses. PMID:21179535

  9. The energy sensor AMPK regulates Hedgehog signaling in human cells through a unique Gli1 metabolic checkpoint

    PubMed Central

    Di Magno, Laura; Basile, Alessio; Coni, Sonia; Manni, Simona; Sdruscia, Giulia; D'Amico, Davide; Antonucci, Laura; Infante, Paola; De Smaele, Enrico; Cucchi, Danilo; Ferretti, Elisabetta; Di Marcotullio, Lucia; Screpanti, Isabella; Canettieri, Gianluca

    2016-01-01

    Hedgehog signaling controls proliferation of cerebellar granule cell precursors (GCPs) and its aberrant activation is a leading cause of Medulloblastoma, the most frequent pediatric brain tumor. We show here that the energy sensor AMPK inhibits Hh signaling by phosphorylating a single residue of human Gli1 that is not conserved in other species. Studies with selective agonists and genetic deletion have revealed that AMPK activation inhibits canonical Hh signaling in human, but not in mouse cells. Indeed we show that AMPK phosphorylates Gli1 at the unique residue Ser408, which is conserved only in primates but not in other species. Once phosphorylated, Gli1 is targeted for proteasomal degradation. Notably, we show that selective AMPK activation inhibits Gli1-driven proliferation and that this effect is linked to Ser408 phosphorylation, which represents a key metabolic checkpoint for Hh signaling. Collectively, this data unveil a novel mechanism of inhibition of Gli1 function, which is exclusive for human cells and may be exploited for the treatment of Medulloblastoma or other Gli1 driven tumors. PMID:26843621

  10. HEDGEHOG-GLI1 signaling regulates human glioma growth, cancer stem cell self-renewal and tumorigenicity

    PubMed Central

    Clement, Virginie; Sanchez, Pilar; de Tribolet, Nicolas; Radovanovic, Ivan; Altaba, Ariel Ruiz i

    2007-01-01

    Summary Cancer stem cells are rare tumor cells characterized by their ability to self-renew and to induce tumorigenesis. They are present in gliomas and may be responsible for the lethality of these incurable brain tumors. In the most aggressive and invasive type, glioblastoma multiforme (GBM), an average of ±1 year spans the period between detection and death (1). The resistence of gliomas to current therapies may be related to the existence of cancer stem cells (2–6). We find that human gliomas display a stemness signature and demonstrate that HEDGEHOG (HH)-GLI signaling regulates the expression of stemness genes in and the self-renewal of CD133+ glioma cancer stem cells. HH-GLI signaling is also required for sustained glioma growth and survival, displaying additive and synergistic effects with temozolomide, the current chemotherapeutic agent of choice, which does not affect glioma stem cell self-renewal. Finally, interference of HH-GLI signaling with cyclopamine or through lentiviral-mediated silencing demonstrates that the tumorigenicity of human gliomas in nude mice requires an active pathway. Our results reveal the essential role of HH-GLI signaling in controlling the behavior of human glioma cancer stem cells and offer new therapeutic possibilities. PMID:17196391

  11. Ablating hedgehog signaling in tenocytes during development impairs biomechanics and matrix organization of the adult murine patellar tendon enthesis.

    PubMed

    Breidenbach, Andrew P; Aschbacher-Smith, Lindsey; Lu, Yinhui; Dyment, Nathaniel A; Liu, Chia-Feng; Liu, Han; Wylie, Chris; Rao, Marepalli; Shearn, Jason T; Rowe, David W; Kadler, Karl E; Jiang, Rulang; Butler, David L

    2015-08-01

    Restoring the native structure of the tendon enthesis, where collagen fibers of the midsubstance are integrated within a fibrocartilaginous structure, is problematic following injury. As current surgical methods fail to restore this region adequately, engineers, biologists, and clinicians are working to understand how this structure forms as a prerequisite to improving repair outcomes. We recently reported on the role of Indian hedgehog (Ihh), a novel enthesis marker, in regulating early postnatal enthesis formation. Here, we investigate how inactivating the Hh pathway in tendon cells affects adult (12-week) murine patellar tendon (PT) enthesis mechanics, fibrocartilage morphology, and collagen fiber organization. We show that ablating Hh signaling resulted in greater than 100% increased failure insertion strain (0.10 v. 0.05 mm/mm, p<0.01) as well as sub-failure biomechanical deficiencies. Although collagen fiber orientation appears overtly normal in the midsubstance, ablating Hh signaling reduces mineralized fibrocartilage by 32%, leading to less collagen embedded within mineralized tissue. Ablating Hh signaling also caused collagen fibers to coalesce at the insertion, which may explain in part the increased strains. These results indicate that Ihh signaling plays a critical role in the mineralization process of fibrocartilaginous entheses and may be a novel therapeutic to promote tendon-to-bone healing.

  12. Modulation of Sonic hedgehog signaling and WW domain containing oxidoreductase WOX1 expression enhances radiosensitivity of human glioblastoma cells

    PubMed Central

    Chiang, Ming-Fu; Chen, Hsin-Hong; Chi, Chih-Wen; Sze, Chun-I; Hsu, Ming-Ling; Shieh, Hui-Ru; Lin, Chin-Ping; Tsai, Jo-Ting

    2015-01-01

    WW domain containing oxidoreductase, designated WWOX, FOR or WOX1, is a known pro-apoptotic factor when ectopically expressed in various types of cancer cells, including glioblastoma multiforme (GBM). The activation of sonic hedgehog (Shh) signaling, especially paracrine Shh secretion in response to radiation, is associated with impairing the effective irradiation of cancer cells. Here, we examined the role of Shh signaling and WOX1 overexpression in the radiosensitivity of human GBM cells. Our results showed that ionizing irradiation (IR) increased the cytoplasmic Shh and nuclear Gli-1 content in GBM U373MG and U87MG cells. GBM cells with exogenous Shh treatment exhibited similar results. Pretreatment with Shh peptides protected U373MG and U87MG cells against IR in a dose-dependent manner. Cyclopamine, a Hedgehog/Smoothened (SMO) inhibitor, reversed the protective effect of Shh in U87MG cells. Cyclopamine increased Shh plus IR-induced H2AX, a marker of DNA double-strand breaks, in these cells. To verify the role of Shh signaling in the radiosensitivity of GBM cells, we tested the effect of the Gli family zinc finger 1 (Gli-1) inhibitor zerumbone and found that it could sensitize GBM cells to IR. We next examined the role of WOX1 in radiosensitivity. Overexpression of WOX1 enhanced the radiosensitivity of U87MG (possessing wild type p53 or WTp53) but not U373MG (harboring mutant p53 or MTp53) cells. Pretreatment with Shh peptides protected both WOX1-overexpressed U373MG and U87MG cells against IR and increased the cytoplasmic Shh and nuclear Gli-1 content. Zerumbone enhanced the radiosensitivity of WOX1-overexpressed U373MG and U87MG cells. In conclusion, overexpression of WOX1 preferentially sensitized human GBM cells possessing wild type p53 to radiation therapy. Blocking of Shh signaling may enhance radiosensitivity independently of the expression of p53 and WOX1. The crosstalk between Shh signaling and WOX1 expression in human glioblastoma warrants further

  13. Structure of the protein core of the glypican Dally-like and localization of a region important for hedgehog signaling

    SciTech Connect

    Kim, Min-Sung; Saunders, Adam M.; Hamaoka, Brent Y.; Beachy, Philip A.; Leahy, Daniel J.

    2011-09-20

    Glypicans are heparan sulfate proteoglycans that modulate the signaling of multiple growth factors active during animal development, and loss of glypican function is associated with widespread developmental abnormalities. Glypicans consist of a conserved, approximately 45-kDa N-terminal protein core region followed by a stalk region that is tethered to the cell membrane by a glycosyl-phosphatidylinositol anchor. The stalk regions are predicted to be random coil but contain a variable number of attachment sites for heparan sulfate chains. Both the N-terminal protein core and the heparan sulfate attachments are important for glypican function. We report here the 2.4-{angstrom} crystal structure of the N-terminal protein core region of the Drosophila glypican Dally-like (Dlp). This structure reveals an elongated, {alpha}-helical fold for glypican core regions that does not appear homologous to any known structure. The Dlp core protein is required for normal responsiveness to Hedgehog (Hh) signals, and we identify a localized region on the Dlp surface important for mediating its function in Hh signaling. Purified Dlp protein core does not, however, interact appreciably with either Hh or an Hh:Ihog complex.

  14. Transposon mutagenesis with coat color genotyping identifies an essential role for Skor2 in sonic hedgehog signaling and cerebellum development

    PubMed Central

    Wang, Baiping; Harrison, Wilbur; Overbeek, Paul A.; Zheng, Hui

    2011-01-01

    Correct development of the cerebellum requires coordinated sonic hedgehog (Shh) signaling from Purkinje to granule cells. How Shh expression is regulated in Purkinje cells is poorly understood. Using a novel tyrosinase minigene-tagged Sleeping Beauty transposon-mediated mutagenesis, which allows for coat color-based genotyping, we created mice in which the Ski/Sno family transcriptional co-repressor 2 (Skor2) gene is deleted. Loss of Skor2 leads to defective Purkinje cell development, a severe reduction of granule cell proliferation and a malformed cerebellum. Skor2 is specifically expressed in Purkinje cells in the brain, where it is required for proper expression of Shh. Skor2 overexpression suppresses BMP signaling in an HDAC-dependent manner and stimulates Shh promoter activity, suggesting that Skor2 represses BMP signaling to activate Shh expression. Our study identifies an essential function for Skor2 as a novel transcriptional regulator in Purkinje cells that acts upstream of Shh during cerebellum development. PMID:21937600

  15. Altered Sonic hedgehog signaling is associated with morphological abnormalities in the penis of the BB/WOR diabetic rat.

    PubMed

    Podlasek, Carol A; Zelner, David J; Harris, Joseph D; Meroz, Cynthia L; Tang, Yi; McKenna, Kevin E; McVary, Kevin T

    2003-09-01

    Erectile dysfunction (ED) is a common and debilitating pathological development that affects up to 75% of diabetic males. Neural stimulation is a crucial aspect of the normal erection process. Nerve injury causes ED and disrupts signaling of the Sonic hedgehog (Shh) cascade in the smooth muscle of the corpora cavernosa. Shh and targets of its signaling establish normal corpora cavernosal morphology during postnatal differentiation of the penis and regulate homeostasis in the adult. Interruption of the Shh cascade in the smooth muscle of the corpora cavernosa results in extensive changes in corpora cavernosal morphology that lead to ED. Our hypothesis is that the neuropathy observed in diabetics causes morphological changes in the corpora cavernosa of the penis that result in ED. Disruption of the Shh cascade may be involved in this process. We tested this hypothesis by examining morphological changes in the penis, altered gene and protein expression, apoptosis, and bromodeoxyuridine incorporation in the BB/WOR rat model of diabetes. Extensive smooth muscle and endothelial degradation was observed in the corpora cavernosa of diabetic penes. This degradation accompanied profound ED, significantly decreased Shh protein in the smooth muscle of the corpora cavernosa, and increased penile Shh RNA expression in the intact penis (nerves, corpora, and urethra). Localization and expression of Shh targets were also disrupted in the corpora cavernosa. Increasing our understanding of the molecular mechanisms that regulate Shh signaling may provide valuable insight into improving treatment options for diabetic impotence. PMID:12748119

  16. Disruption of sonic hedgehog signaling in Ellis-van Creveld dwarfism confers protection against bipolar affective disorder.

    PubMed

    Ginns, E I; Galdzicka, M; Elston, R C; Song, Y E; Paul, S M; Egeland, J A

    2015-10-01

    Ellis-van Creveld syndrome, an autosomal recessively inherited chondrodysplastic dwarfism, is frequent among Old Order Amish of Pennsylvania. Decades of longitudinal research on bipolar affective disorder (BPAD) revealed cosegregation of high numbers of EvC and Bipolar I (BPI) cases in several large Amish families descending from the same pioneer. Despite the high prevalence of both disorders in these families, no EvC individual has ever been reported with BPI. The proximity of the EVC gene to our previously reported chromosome 4p16 BPAD locus with protective alleles, coupled with detailed clinical observations that EvC and BPI do not occur in the same individuals, led us to hypothesize that the genetic defect causing EvC in the Amish confers protection from BPI. This hypothesis is supported by a significant negative association of these two disorders when contrasted with absence of disease (P=0.029, Fisher's exact test, two-sided, verified by permutation to estimate the null distribution of the test statistic). As homozygous Amish EVC mutations causing EvC dwarfism do so by disrupting sonic hedgehog (Shh) signaling, our data implicate Shh signaling in the underlying pathophysiology of BPAD. Understanding how disrupted Shh signaling protects against BPI could uncover variants in the Shh pathway that cause or increase risk for this and related mood disorders.

  17. Phosphodiesterase 4D acts downstream of Neuropilin to control Hedgehog signal transduction and the growth of medulloblastoma.

    PubMed

    Ge, Xuecai; Milenkovic, Ljiljana; Suyama, Kaye; Hartl, Tom; Purzner, Teresa; Winans, Amy; Meyer, Tobias; Scott, Matthew P

    2015-01-01

    Alterations in Hedgehog (Hh) signaling lead to birth defects and cancers including medulloblastoma, the most common pediatric brain tumor. Although inhibitors targeting the membrane protein Smoothened suppress Hh signaling, acquired drug resistance and tumor relapse call for additional therapeutic targets. Here we show that phosphodiesterase 4D (PDE4D) acts downstream of Neuropilins to control Hh transduction and medulloblastoma growth. PDE4D interacts directly with Neuropilins, positive regulators of Hh pathway. The Neuropilin ligand Semaphorin3 enhances this interaction, promoting PDE4D translocation to the plasma membrane and cAMP degradation. The consequent inhibition of protein kinase A (PKA) enhances Hh transduction. In the developing cerebellum, genetic removal of Neuropilins reduces Hh signaling activity and suppresses proliferation of granule neuron precursors. In mouse medulloblastoma allografts, PDE4D inhibitors suppress Hh transduction and inhibit tumor growth. Our findings reveal a new regulatory mechanism of Hh transduction, and highlight PDE4D as a promising target to treat Hh-related tumors. PMID:26371509

  18. Embryonic tongue morphogenesis in an organ culture model of mouse mandibular arches: blocking Sonic hedgehog signaling leads to microglossia.

    PubMed

    Torii, Daisuke; Soeno, Yuuichi; Fujita, Kazuya; Sato, Kaori; Aoba, Takaaki; Taya, Yuji

    2016-01-01

    Mouse tongue development is initiated with the formation of lateral lingual swellings just before fusion between the mediodorsal surfaces of the mandibular arches at around embryonic day 11.0. Here, we investigated the role of Sonic hedgehog (Shh) signaling in embryonic mouse tongue morphogenesis. For this, we used an organ culture model of the mandibular arches from mouse embryos at embryonic day 10.5. When the Shh signaling inhibitor jervine was added to the culture medium for 24-96 h, the formation of lateral lingual swellings and subsequent epithelial invagination into the mesenchyme were impaired markedly, leading to a hypoplastic tongue with an incomplete oral sulcus. Notably, jervine treatment reduced the proliferation of non-myogenic mesenchymal cells at the onset of forming the lateral lingual swellings, whereas it did not affect the proliferation and differentiation of a myogenic cell lineage, which created a cell community at the central circumferential region of the lateral lingual swellings as seen in vivo and in control cultures lacking the inhibitor. Thus, epithelium-derived Shh signaling stimulates the proliferation of non-myogenic mesenchymal cells essential for forming lateral lingual swellings and contributes to epithelial invagination into the mesenchyme during early tongue development.

  19. Phosphodiesterase 4D acts downstream of Neuropilin to control Hedgehog signal transduction and the growth of medulloblastoma

    PubMed Central

    Ge, Xuecai; Milenkovic, Ljiljana; Suyama, Kaye; Hartl, Tom; Purzner, Teresa; Winans, Amy; Meyer, Tobias; Scott, Matthew P

    2015-01-01

    Alterations in Hedgehog (Hh) signaling lead to birth defects and cancers including medulloblastoma, the most common pediatric brain tumor. Although inhibitors targeting the membrane protein Smoothened suppress Hh signaling, acquired drug resistance and tumor relapse call for additional therapeutic targets. Here we show that phosphodiesterase 4D (PDE4D) acts downstream of Neuropilins to control Hh transduction and medulloblastoma growth. PDE4D interacts directly with Neuropilins, positive regulators of Hh pathway. The Neuropilin ligand Semaphorin3 enhances this interaction, promoting PDE4D translocation to the plasma membrane and cAMP degradation. The consequent inhibition of protein kinase A (PKA) enhances Hh transduction. In the developing cerebellum, genetic removal of Neuropilins reduces Hh signaling activity and suppresses proliferation of granule neuron precursors. In mouse medulloblastoma allografts, PDE4D inhibitors suppress Hh transduction and inhibit tumor growth. Our findings reveal a new regulatory mechanism of Hh transduction, and highlight PDE4D as a promising target to treat Hh-related tumors. DOI: http://dx.doi.org/10.7554/eLife.07068.001 PMID:26371509

  20. SDCCAG8 Interacts with RAB Effector Proteins RABEP2 and ERC1 and Is Required for Hedgehog Signaling

    PubMed Central

    Schueler, Markus; Airik, Merlin; Cho, Jang; Ulanowicz, Kelsey A.; Porath, Jonathan D.; Hurd, Toby W.; Bekker-Jensen, Simon; Schrøder, Jacob M.; Andersen, Jens S.; Hildebrandt, Friedhelm

    2016-01-01

    Recessive mutations in the SDCCAG8 gene cause a nephronophthisis-related ciliopathy with Bardet-Biedl syndrome-like features in humans. Our previous characterization of the orthologous Sdccag8gt/gt mouse model recapitulated the retinal-renal disease phenotypes and identified impaired DNA damage response signaling as an underlying disease mechanism in the kidney. However, several other phenotypic and mechanistic features of Sdccag8gt/gt mice remained unexplored. Here we show that Sdccag8gt/gt mice exhibit developmental and structural abnormalities of the skeleton and limbs, suggesting impaired Hedgehog (Hh) signaling. Indeed, cell culture studies demonstrate the requirement of SDCCAG8 for ciliogenesis and Hh signaling. Using an affinity proteomics approach, we demonstrate that SDCCAG8 interacts with proteins of the centriolar satellites (OFD1, AZI1), of the endosomal sorting complex (RABEP2, ERC1), and with non-muscle myosin motor proteins (MYH9, MYH10, MYH14) at the centrosome. Furthermore, we show that RABEP2 localization at the centrosome is regulated by SDCCAG8. siRNA mediated RABEP2 knockdown in hTERT-RPE1 cells leads to defective ciliogenesis, indicating a critical role for RABEP2 in this process. Together, this study identifies several centrosome-associated proteins as novel SDCCAG8 interaction partners, and provides new insights into the function of SDCCAG8 at this structure. PMID:27224062

  1. Nek2A phosphorylates and stabilizes SuFu: A new strategy of Gli2/Hedgehog signaling regulatory mechanism.

    PubMed

    Wang, Yao; Li, Yong; Hu, Guanghui; Huang, Xuan; Rao, Hai; Xiong, Xiangyang; Luo, Zhijun; Lu, Quqin; Luo, Shiwen

    2016-09-01

    Suppressor of Fused (SuFu) plays a conservative role in the regulation of the Gli transcription factors within the Hedgehog (Hh) signaling pathway. Despite the central importance of SuFu in the Hh pathway, little is known about its regulation. Here, we performed a GAL4-based yeast two-hybrid screen using human SuFu as bait, and identified NIMA-related expressed kinase 2A (Nek2A) as a new SuFu-interacting protein, which was also confirmed by glutathione-S-transferase pull-down and co-immunoprecipitation assays. Intriguingly, Nek2A is found to stabilize SuFu at least partly depending on its kinase activity, thereby triggering phosphorylation of the SuFu protein. Moreover, the phosphorylated SuFu inhibits the nuclear localization and transcriptional activity of Gli2/Hh signaling. These findings reveal a new mechanism of mammalian SuFu regulation, and offers novel insights into Hh signaling regulation in development and human disease. PMID:27297360

  2. SDCCAG8 Interacts with RAB Effector Proteins RABEP2 and ERC1 and Is Required for Hedgehog Signaling.

    PubMed

    Airik, Rannar; Schueler, Markus; Airik, Merlin; Cho, Jang; Ulanowicz, Kelsey A; Porath, Jonathan D; Hurd, Toby W; Bekker-Jensen, Simon; Schrøder, Jacob M; Andersen, Jens S; Hildebrandt, Friedhelm

    2016-01-01

    Recessive mutations in the SDCCAG8 gene cause a nephronophthisis-related ciliopathy with Bardet-Biedl syndrome-like features in humans. Our previous characterization of the orthologous Sdccag8gt/gt mouse model recapitulated the retinal-renal disease phenotypes and identified impaired DNA damage response signaling as an underlying disease mechanism in the kidney. However, several other phenotypic and mechanistic features of Sdccag8gt/gt mice remained unexplored. Here we show that Sdccag8gt/gt mice exhibit developmental and structural abnormalities of the skeleton and limbs, suggesting impaired Hedgehog (Hh) signaling. Indeed, cell culture studies demonstrate the requirement of SDCCAG8 for ciliogenesis and Hh signaling. Using an affinity proteomics approach, we demonstrate that SDCCAG8 interacts with proteins of the centriolar satellites (OFD1, AZI1), of the endosomal sorting complex (RABEP2, ERC1), and with non-muscle myosin motor proteins (MYH9, MYH10, MYH14) at the centrosome. Furthermore, we show that RABEP2 localization at the centrosome is regulated by SDCCAG8. siRNA mediated RABEP2 knockdown in hTERT-RPE1 cells leads to defective ciliogenesis, indicating a critical role for RABEP2 in this process. Together, this study identifies several centrosome-associated proteins as novel SDCCAG8 interaction partners, and provides new insights into the function of SDCCAG8 at this structure. PMID:27224062

  3. Cell Division Mode Change Mediates the Regulation of Cerebellar Granule Neurogenesis Controlled by the Sonic Hedgehog Signaling

    PubMed Central

    Yang, Rong; Wang, Minglei; Wang, Jia; Huang, Xingxu; Yang, Ru; Gao, Wei-Qiang

    2015-01-01

    Summary Symmetric and asymmetric divisions are important for self-renewal and differentiation of stem cells during neurogenesis. Although cerebellar granule neurogenesis is controlled by sonic hedgehog (SHH) signaling, whether and how this process is mediated by regulation of cell division modes have not been determined. Here, using time-lapse imaging and cell culture from neuronal progenitor-specific and differentiated neuron-specific reporter mouse lines (Math1-GFP and Dcx-DsRed) and Patched+/− mice in which SHH signaling is activated, we find evidence for the existence of symmetric and asymmetric divisions that are closely associated with progenitor proliferation and differentiation. While activation of the SHH pathway enhances symmetric progenitor cell divisions, blockade of the SHH pathway reverses the cell division mode change in Math1-GFP;Dcx-DsRed;Patched+/− mice by promoting asymmetric divisions or terminal neuronal symmetric divisions. Thus, cell division mode change mediates the regulation of cerebellar granule neurogenesis controlled by SHH signaling. PMID:26527387

  4. Transposon mutagenesis with coat color genotyping identifies an essential role for Skor2 in sonic hedgehog signaling and cerebellum development.

    PubMed

    Wang, Baiping; Harrison, Wilbur; Overbeek, Paul A; Zheng, Hui

    2011-10-01

    Correct development of the cerebellum requires coordinated sonic hedgehog (Shh) signaling from Purkinje to granule cells. How Shh expression is regulated in Purkinje cells is poorly understood. Using a novel tyrosinase minigene-tagged Sleeping Beauty transposon-mediated mutagenesis, which allows for coat color-based genotyping, we created mice in which the Ski/Sno family transcriptional co-repressor 2 (Skor2) gene is deleted. Loss of Skor2 leads to defective Purkinje cell development, a severe reduction of granule cell proliferation and a malformed cerebellum. Skor2 is specifically expressed in Purkinje cells in the brain, where it is required for proper expression of Shh. Skor2 overexpression suppresses BMP signaling in an HDAC-dependent manner and stimulates Shh promoter activity, suggesting that Skor2 represses BMP signaling to activate Shh expression. Our study identifies an essential function for Skor2 as a novel transcriptional regulator in Purkinje cells that acts upstream of Shh during cerebellum development. PMID:21937600

  5. Resveratrol inhibits the hedgehog signaling pathway and epithelial-mesenchymal transition and suppresses gastric cancer invasion and metastasis

    PubMed Central

    GAO, QIAN; YUAN, YUAN; GAN, HUI-ZHONG; PENG, QIONG

    2015-01-01

    The hedgehog (Hh) signaling pathway is vital to vertebrate development, the homeostatic process and tumorigenesis. Epithelial-mesenchymal transition (EMT) is a cellular process during which epithelial cells become mesenchymal-appearing cells, which in turn promotes cancer metastasis and invasion. Resveratrol is a natural polyphenolic compound found in grapes, a variety of berries, peanuts and other plants. Numerous studies have demonstrated that the Hh signaling pathway is able to regulate the EMT, and that resveratrol can suppress carcinoma invasion and metastasis. In addition, certain studies have indicated that resveratrol can inhibit the Hh signaling pathway and EMT in cancers other than gastric cancer. The purpose of the present study was to investigate the inhibitory effect of resveratrol on the Hh signaling pathway and EMT in gastric cancer in vitro. Gastric cancer SGC-7901 cells were treated with resveratrol or cyclopamine at different concentrations. The viability of the cells was assessed using an MTT assay. The expression of Gli-1, a key component of the Hh signaling pathway, and Snail, E-cadherin and N-cadherin, key components of EMT, was detected by reverse transcription polymerase chain reaction (RT-PCR) and western blotting. The invasion and metastasis of the cells were observed by performing a cell scratch test. The RT-PCR and western blotting showed a decrease in Gli-1, Snail and N-cadherin expression, and an increase in E-cadherin expression in the resveratrol and cyclopamine group compared with the control group, suggesting that resveratrol inhibited the Hh pathway and EMT, as did cyclopamine. The MTT assay indicated that the viability of the SGC-7901 cells was significantly decreased in a concentration-dependent manner following resveratrol and cyclopamine treatment. The cell scratch test showed slower cell invasion and metastasis in the resveratrol and cyclopamine groups. These findings indicated that resveratrol was able to inhibit the Hh

  6. Expression pattern of sonic hedgehog signaling and calcitonin gene-related peptide in the socket healing process after tooth extraction.

    PubMed

    Pang, Pai; Shimo, Tsuyoshi; Takada, Hiroyuki; Matsumoto, Kenichi; Yoshioka, Norie; Ibaragi, Soichiro; Sasaki, Akira

    2015-11-01

    Sonic Hedgehog (SHH), a neural development inducer, plays a significant role in the bone healing process. Calcitonin gene-related peptide (CGRP), a neuropeptide marker of sensory nerves, has been demonstrated to affect bone formation. The roles of SHH signaling and CGRP-positive sensory nerves in the alveolar bone formation process have been unknown. Here we examined the expression patterns of SHH signaling and CGRP in mouse socket by immunohistochemistry and immunofluorescence analysis. We found that the expression level of SHH peaked at day 3 and was then decreased at 5 days after tooth extraction. CGRP, PTCH1 and GLI2 were each expressed in a similar pattern with their highest expression levels at day 5 and day 7 after tooth extraction. CGRP and GLI2 were co-expressed in some inflammatory cells and bone forming cells. In some areas, CGRP-positive neurons expressed GLI2. In conclusion, SHH may affect alveolar bone healing by interacting with CGRP-positive sensory neurons and thus regulate the socket's healing process after tooth extraction. PMID:26427874

  7. miR-326 is downstream of Sonic hedgehog signaling and regulates the expression of Gli2 and smoothened.

    PubMed

    Jiang, Zhihua; Cushing, Leah; Ai, Xingbin; Lü, Jining

    2014-08-01

    Sonic hedgehog (Shh) is expressed and secreted from the embryonic lung epithelium and acts on the adjacent mesenchymal cells via its receptor Patched (Ptch)/Smoothened (Smo) and transcriptional effectors Gli proteins. Genetic studies showed that the Shh pathway plays critical roles in mouse lung development. However, little is known about microRNAs (miRNAs) downstream of Shh in embryonic lungs. Here we profiled miRNAs in embryonic lung cultures treated with cyclopamine, a specific Smo antagonist or with Smo agonist by next-generation of sequencing. We then performed functional screening to examine whether some of these miRNAs can modulate the induction of Gli-responsive luciferase by Shh treatment. These analyses revealed that expression of miR-326 and its host gene, Arrestin β1, is selectively enriched in embryonic lung mesenchymal cells and is specifically influenced by Shh activity. Furthermore, functional analyses showed that miR-326 acts as a negative modulator for Shh signaling by directly targeting Smo and Gli2. Together, these findings suggest a novel miR-326-negative feedback loop in regulating the activity of Shh signaling.

  8. Deregulated hedgehog pathway signaling is inhibited by the smoothened antagonist LDE225 (Sonidegib) in chronic phase chronic myeloid leukaemia.

    PubMed

    Irvine, David A; Zhang, Bin; Kinstrie, Ross; Tarafdar, Anuradha; Morrison, Heather; Campbell, Victoria L; Moka, Hothri A; Ho, Yinwei; Nixon, Colin; Manley, Paul W; Wheadon, Helen; Goodlad, John R; Holyoake, Tessa L; Bhatia, Ravi; Copland, Mhairi

    2016-01-01

    Targeting the Hedgehog (Hh) pathway represents a potential leukaemia stem cell (LSC)-directed therapy which may compliment tyrosine kinase inhibitors (TKIs) to eradicate LSC in chronic phase (CP) chronic myeloid leukaemia (CML). We set out to elucidate the role of Hh signaling in CP-CML and determine if inhibition of Hh signaling, through inhibition of smoothened (SMO), was an effective strategy to target CP-CML LSC. Assessment of Hh pathway gene and protein expression demonstrated that the Hh pathway is activated in CD34(+) CP-CML stem/progenitor cells. LDE225 (Sonidegib), a small molecule, clinically investigated SMO inhibitor, used alone and in combination with nilotinib, inhibited the Hh pathway in CD34(+) CP-CML cells, reducing the number and self-renewal capacity of CML LSC in vitro. The combination had no effect on normal haemopoietic stem cells. When combined, LDE225 + nilotinib reduced CD34(+) CP-CML cell engraftment in NSG mice and, upon administration to EGFP(+) /SCLtTA/TRE-BCR-ABL mice, the combination enhanced survival with reduced leukaemia development in secondary transplant recipients. In conclusion, the Hh pathway is deregulated in CML stem and progenitor cells. We identify Hh pathway inhibition, in combination with nilotinib, as a potentially effective therapeutic strategy to improve responses in CP-CML by targeting both stem and progenitor cells. PMID:27157927

  9. RAB23 Mutations in Carpenter Syndrome Imply an Unexpected Role for Hedgehog Signaling in Cranial-Suture Development and Obesity

    PubMed Central

    Jenkins, Dagan ; Seelow, Dominik ; Jehee, Fernanda S. ; Perlyn, Chad A. ; Alonso, Luís G. ; Bueno, Daniela F. ; Donnai, Dian ; Josifiova, Dragana ; Mathijssen, Irene M. J. ; Morton, Jenny E. V. ; Ørstavik, Karen Helene ; Sweeney, Elizabeth ; Wall, Steven A. ; Marsh, Jeffrey L. ; Nürnberg, Peter ; Passos-Bueno, Maria Rita ; Wilkie, Andrew O. M. 

    2007-01-01

    Carpenter syndrome is a pleiotropic disorder with autosomal recessive inheritance, the cardinal features of which include craniosynostosis, polysyndactyly, obesity, and cardiac defects. Using homozygosity mapping, we found linkage to chromosome 6p12.1-q12 and, in 15 independent families, identified five different mutations (four truncating and one missense) in RAB23, which encodes a member of the RAB guanosine triphosphatase (GTPase) family of vesicle transport proteins and acts as a negative regulator of hedgehog (HH) signaling. In 10 patients, the disease was caused by homozygosity for the same nonsense mutation, L145X, that resides on a common haplotype, indicative of a founder effect in patients of northern European descent. Surprisingly, nonsense mutations of Rab23 in open brain mice cause recessive embryonic lethality with neural-tube defects, suggesting a species difference in the requirement for RAB23 during early development. The discovery of RAB23 mutations in patients with Carpenter syndrome implicates HH signaling in cranial-suture biogenesis—an unexpected finding, given that craniosynostosis is not usually associated with mutations of other HH-pathway components—and provides a new molecular target for studies of obesity. PMID:17503333

  10. Deregulated hedgehog pathway signaling is inhibited by the smoothened antagonist LDE225 (Sonidegib) in chronic phase chronic myeloid leukaemia

    PubMed Central

    Irvine, David A.; Zhang, Bin; Kinstrie, Ross; Tarafdar, Anuradha; Morrison, Heather; Campbell, Victoria L.; Moka, Hothri A.; Ho, Yinwei; Nixon, Colin; Manley, Paul W.; Wheadon, Helen; Goodlad, John R.; Holyoake, Tessa L.; Bhatia, Ravi; Copland, Mhairi

    2016-01-01

    Targeting the Hedgehog (Hh) pathway represents a potential leukaemia stem cell (LSC)-directed therapy which may compliment tyrosine kinase inhibitors (TKIs) to eradicate LSC in chronic phase (CP) chronic myeloid leukaemia (CML). We set out to elucidate the role of Hh signaling in CP-CML and determine if inhibition of Hh signaling, through inhibition of smoothened (SMO), was an effective strategy to target CP-CML LSC. Assessment of Hh pathway gene and protein expression demonstrated that the Hh pathway is activated in CD34+ CP-CML stem/progenitor cells. LDE225 (Sonidegib), a small molecule, clinically investigated SMO inhibitor, used alone and in combination with nilotinib, inhibited the Hh pathway in CD34+ CP-CML cells, reducing the number and self-renewal capacity of CML LSC in vitro. The combination had no effect on normal haemopoietic stem cells. When combined, LDE225 + nilotinib reduced CD34+ CP-CML cell engraftment in NSG mice and, upon administration to EGFP+ /SCLtTA/TRE-BCR-ABL mice, the combination enhanced survival with reduced leukaemia development in secondary transplant recipients. In conclusion, the Hh pathway is deregulated in CML stem and progenitor cells. We identify Hh pathway inhibition, in combination with nilotinib, as a potentially effective therapeutic strategy to improve responses in CP-CML by targeting both stem and progenitor cells. PMID:27157927

  11. Sonic hedgehog acts as a negative regulator of {beta}-catenin signaling in the adult tongue epithelium.

    PubMed

    Schneider, Fabian T; Schänzer, Anne; Czupalla, Cathrin J; Thom, Sonja; Engels, Knut; Schmidt, Mirko H H; Plate, Karl H; Liebner, Stefan

    2010-07-01

    Wnt/beta-catenin signaling has been implicated in taste papilla development; however, its role in epithelial maintenance and tumor progression in the adult tongue remains elusive. We show Wnt/beta-catenin pathway activation in reporter mice and by nuclear beta-catenin staining in the epithelium and taste papilla of adult mouse and human tongues. beta-Catenin activation in APC(min/+) mice, which carry a mutation in adenomatous poliposis coli (APC), up-regulates Sonic hedgehog (Shh) and Jagged-2 (JAG2) in the tongue epithelium without formation of squamous cell carcinoma (SCC). We demonstrate that Shh suppresses beta-catenin transcriptional activity in a signaling-dependent manner in vitro and in vivo. A similar regulation and function was observed for JAG2, suggesting that both pathways negatively regulate beta-catenin, thereby preventing SCC formation in the tongue. This was supported by reduced nuclear beta-catenin in the tongue epithelium of Patched(+/-) mice, exhibiting dominant active Shh signaling. At the invasive front of human tongue cancer, nuclear beta-catenin and Shh were increased, suggesting their participation in tumor progression. Interestingly, Shh but not JAG2 was able to reduce beta-catenin signaling in SCC cells, arguing for a partial loss of negative feedback on beta-catenin transcription in tongue cancer. We show for the first time that the putative Wnt/beta-catenin targets Shh and JAG2 control beta-catenin signaling in the adult tongue epithelium, a function that is partially lost in lingual SCC. PMID:20508033

  12. Hedgehog Signaling Strength Is Orchestrated by the mir-310 Cluster of MicroRNAs in Response to Diet

    PubMed Central

    Çiçek, Ibrahim Ömer; Karaca, Samir; Brankatschk, Marko; Eaton, Suzanne; Urlaub, Henning; Shcherbata, Halyna R.

    2016-01-01

    Since the discovery of microRNAs (miRNAs) only two decades ago, they have emerged as an essential component of the gene regulatory machinery. miRNAs have seemingly paradoxical features: a single miRNA is able to simultaneously target hundreds of genes, while its presence is mostly dispensable for animal viability under normal conditions. It is known that miRNAs act as stress response factors; however, it remains challenging to determine their relevant targets and the conditions under which they function. To address this challenge, we propose a new workflow for miRNA function analysis, by which we found that the evolutionarily young miRNA family, the mir-310s (mir-310/mir-311/mir-312/mir-313), are important regulators of Drosophila metabolic status. mir-310s-deficient animals have an abnormal diet-dependent expression profile for numerous diet-sensitive components, accumulate fats, and show various physiological defects. We found that the mir-310s simultaneously repress the production of several regulatory factors (Rab23, DHR96, and Ttk) of the evolutionarily conserved Hedgehog (Hh) pathway to sharpen dietary response. As the mir-310s expression is highly dynamic and nutrition sensitive, this signal relay model helps to explain the molecular mechanism governing quick and robust Hh signaling responses to nutritional changes. Additionally, we discovered a new component of the Hh signaling pathway in Drosophila, Rab23, which cell autonomously regulates Hh ligand trafficking in the germline stem cell niche. How organisms adjust to dietary fluctuations to sustain healthy homeostasis is an intriguing research topic. These data are the first to report that miRNAs can act as executives that transduce nutritional signals to an essential signaling pathway. This suggests miRNAs as plausible therapeutic agents that can be used in combination with low calorie and cholesterol diets to manage quick and precise tissue-specific responses to nutritional changes. PMID:26801178

  13. Protein-bound Polysaccharide-K Inhibits Hedgehog Signaling Through Down-regulation of MAML3 and RBPJ Transcription Under Hypoxia, Suppressing the Malignant Phenotype in Pancreatic Cancer.

    PubMed

    Yamasaki, Akio; Onishi, Hideya; Imaizumi, Akira; Kawamoto, Makoto; Fujimura, Akiko; Oyama, Yasuhiro; Katano, Mitsuo

    2016-08-01

    Hedgehog signaling is activated in pancreatic cancer and could be a therapeutic target. We previously demonstrated that recombination signal binding protein for immunoglobulin-kappa-J region (RBPJ) and mastermind-like 3 (MAML3) contribute to the hypoxia-induced up-regulation of Smoothened (SMO) transcription. We have also shown that protein-bound polysaccharide-K (PSK) could be effective for refractory pancreatic cancer that down-regulates SMO transcription under hypoxia. In this study, we evaluated whether the anticancer mechanism of PSK involves inhibiting RBPJ and MAML3 expression under hypoxia. PSK reduced SMO, MAML3 and RBPJ expression in pancreatic cancer cells under hypoxia. PSK also blocked RBPJ-induced invasiveness under hypoxia by inhibiting matrix metalloproteinase expression. Lastly, we showed that PSK attenuated RBPJ-induced proliferation both in vitro and in vivo. These results suggest that PSK suppresses Hedgehog signaling through down-regulation of MAML3 and RBPJ transcription under hypoxia, inhibiting the induction of a malignant phenotype in pancreatic cancer. Our results may lead to development of new treatments for refractory pancreatic cancer using PSK as a Hedgehog inhibitor. PMID:27466498

  14. MicroRNA Biogenesis and Hedgehog-Patched Signaling Cooperate to Regulate an Important Developmental Transition in Granule Cell Development.

    PubMed

    Constantin, Lena; Constantin, Myrna; Wainwright, Brandon J

    2016-03-01

    The Dicer1, Dcr-1 homolog (Drosophila) gene encodes a type III ribonuclease required for the canonical maturation and functioning of microRNAs (miRNAs). Subsets of miRNAs are known to regulate normal cerebellar granule cell development, in addition to the growth and progression of medulloblastoma, a neoplasm that often originates from granule cell precursors. Multiple independent studies have also demonstrated that deregulation of Sonic Hedgehog (Shh)-Patched (Ptch) signaling, through miRNAs, is causative of granule cell pathologies. In the present study, we investigated the genetic interplay between miRNA biogenesis and Shh-Ptch signaling in granule cells of the cerebellum by way of the Cre/lox recombination system in genetically engineered models of Mus musculus (mouse). We demonstrate that, although the miRNA biogenesis and Shh-Ptch-signaling pathways, respectively, regulate the opposing growth processes of cerebellar hypoplasia and hyperplasia leading to medulloblastoma, their concurrent deregulation was nonadditive and did not bring the growth phenotypes toward an expected equilibrium. Instead, mice developed either hypoplasia or medulloblastoma, but of a greater severity. Furthermore, some genotypes were bistable, whereby subsets of mice developed hypoplasia or medulloblastoma. This implies that miRNAs and Shh-Ptch signaling regulate an important developmental transition in granule cells of the cerebellum. We also conclusively show that the Dicer1 gene encodes a haploinsufficient tumor suppressor gene for Ptch1-induced medulloblastoma, with the monoallielic loss of Dicer1 more severe than biallelic loss. These findings exemplify how genetic interplay between pathways may produce nonadditive effects with a substantial and unpredictable impact on biology. Furthermore, these findings suggest that the functional dosage of Dicer1 may nonadditively influence a wide range of Shh-Ptch-dependent pathologies. PMID:26773048

  15. Polycomb-Mediated Repression and Sonic Hedgehog Signaling Interact to Regulate Merkel Cell Specification during Skin Development.

    PubMed

    Perdigoto, Carolina N; Dauber, Katherine L; Bar, Carmit; Tsai, Pai-Chi; Valdes, Victor J; Cohen, Idan; Santoriello, Francis J; Zhao, Dejian; Zheng, Deyou; Hsu, Ya-Chieh; Ezhkova, Elena

    2016-07-01

    An increasing amount of evidence indicates that developmental programs are tightly regulated by the complex interplay between signaling pathways, as well as transcriptional and epigenetic processes. Here, we have uncovered coordination between transcriptional and morphogen cues to specify Merkel cells, poorly understood skin cells that mediate light touch sensations. In murine dorsal skin, Merkel cells are part of touch domes, which are skin structures consisting of specialized keratinocytes, Merkel cells, and afferent neurons, and are located exclusively around primary hair follicles. We show that the developing primary hair follicle functions as a niche required for Merkel cell specification. We find that intraepidermal Sonic hedgehog (Shh) signaling, initiated by the production of Shh ligand in the developing hair follicles, is required for Merkel cell specification. The importance of Shh for Merkel cell formation is further reinforced by the fact that Shh overexpression in embryonic epidermal progenitors leads to ectopic Merkel cells. Interestingly, Shh signaling is common to primary, secondary, and tertiary hair follicles, raising the possibility that there are restrictive mechanisms that regulate Merkel cell specification exclusively around primary hair follicles. Indeed, we find that loss of Polycomb repressive complex 2 (PRC2) in the epidermis results in the formation of ectopic Merkel cells that are associated with all hair types. We show that PRC2 loss expands the field of epidermal cells competent to differentiate into Merkel cells through the upregulation of key Merkel-differentiation genes, which are known PRC2 targets. Importantly, PRC2-mediated repression of the Merkel cell differentiation program requires inductive Shh signaling to form mature Merkel cells. Our study exemplifies how the interplay between epigenetic and morphogen cues regulates the complex patterning and formation of the mammalian skin structures. PMID:27414999

  16. Prenatal cadmium exposure dysregulates sonic hedgehog and Wnt/beta-catenin signaling in the thymus resulting in altered thymocyte development

    SciTech Connect

    Hanson, Miranda L.; Brundage, Kathleen M.; Schafer, Rosana; Tou, Janet C.; Barnett, John B.

    2010-01-15

    Cadmium (Cd) is both an environmental pollutant and a component of cigarette smoke. Although evidence demonstrates that adult exposure to Cd causes changes in the immune system, there are limited reports in the literature of immunomodulatory effects of prenatal exposure to Cd. The sonic hedgehog (Shh) and Wnt/beta-catenin pathways are required for thymocyte maturation. Several studies have demonstrated that Cd exposure affects these pathways in different organ systems. This study was designed to investigate the effect of prenatal Cd exposure on thymocyte development, and to determine if these effects were linked to dysregulation of Shh and Wnt/beta-catenin pathways. Pregnant C57Bl/6 mice were exposed to an environmentally relevant dose (10 ppm) of Cd throughout pregnancy and effects on the thymus were assessed on the day of birth. Thymocyte phenotype was determined by flow cytometry. A Gli:luciferase reporter cell line was used to measure Shh signaling. Transcription of target genes and translation of key components of both signaling pathways were assessed using real-time RT-PCR and western blot, respectively. Prenatal Cd exposure increased the number of CD4{sup +} cells and a subpopulation of double-negative cells (DN; CD4{sup -}CD8{sup -}), DN4 (CD44{sup -}CD25{sup -}). Shh and Wnt/beta-catenin signaling were both decreased in the thymus. Target genes of Shh (Patched1 and Gli1) and Wnt/beta-catenin (c-fos, and c-myc) were affected differentially among thymocyte subpopulations. These findings suggest that prenatal exposure to Cd dysregulates two signaling pathways in the thymus, resulting in altered thymocyte development.

  17. Polycomb-Mediated Repression and Sonic Hedgehog Signaling Interact to Regulate Merkel Cell Specification during Skin Development

    PubMed Central

    Bar, Carmit; Tsai, Pai-Chi; Valdes, Victor J.; Cohen, Idan; Santoriello, Francis J.; Zhao, Dejian; Hsu, Ya-Chieh; Ezhkova, Elena

    2016-01-01

    An increasing amount of evidence indicates that developmental programs are tightly regulated by the complex interplay between signaling pathways, as well as transcriptional and epigenetic processes. Here, we have uncovered coordination between transcriptional and morphogen cues to specify Merkel cells, poorly understood skin cells that mediate light touch sensations. In murine dorsal skin, Merkel cells are part of touch domes, which are skin structures consisting of specialized keratinocytes, Merkel cells, and afferent neurons, and are located exclusively around primary hair follicles. We show that the developing primary hair follicle functions as a niche required for Merkel cell specification. We find that intraepidermal Sonic hedgehog (Shh) signaling, initiated by the production of Shh ligand in the developing hair follicles, is required for Merkel cell specification. The importance of Shh for Merkel cell formation is further reinforced by the fact that Shh overexpression in embryonic epidermal progenitors leads to ectopic Merkel cells. Interestingly, Shh signaling is common to primary, secondary, and tertiary hair follicles, raising the possibility that there are restrictive mechanisms that regulate Merkel cell specification exclusively around primary hair follicles. Indeed, we find that loss of Polycomb repressive complex 2 (PRC2) in the epidermis results in the formation of ectopic Merkel cells that are associated with all hair types. We show that PRC2 loss expands the field of epidermal cells competent to differentiate into Merkel cells through the upregulation of key Merkel-differentiation genes, which are known PRC2 targets. Importantly, PRC2-mediated repression of the Merkel cell differentiation program requires inductive Shh signaling to form mature Merkel cells. Our study exemplifies how the interplay between epigenetic and morphogen cues regulates the complex patterning and formation of the mammalian skin structures. PMID:27414999

  18. Mutations in BMP4 Cause Eye, Brain, and Digit Developmental Anomalies: Overlap between the BMP4 and Hedgehog Signaling Pathways

    PubMed Central

    Bakrania, Preeti; Efthymiou, Maria; Klein, Johannes C.; Salt, Alison; Bunyan, David J.; Wyatt, Alex; Ponting, Chris P.; Martin, Angela; Williams, Steven; Lindley, Victoria; Gilmore, Joanne; Restori, Marie; Robson, Anthony G.; Neveu, Magella M.; Holder, Graham E.; Collin, J Richard O.; Robinson, David O.; Farndon, Peter; Johansen-Berg, Heidi; Gerrelli, Dianne; Ragge, Nicola K.

    2008-01-01

    Developmental ocular malformations, including anophthalmia-microphthalmia (AM), are heterogeneous disorders with frequent sporadic or non-Mendelian inheritance. Recurrent interstitial deletions of 14q22-q23 have been associated with AM, sometimes with poly/syndactyly and hypopituitarism. We identify two further cases of AM (one with associated pituitary anomalies) with a 14q22-q23 deletion. Using a positional candidate gene approach, we analyzed the BMP4 (Bone Morphogenetic Protein-4) gene and identified a frameshift mutation (c.226del2, p.S76fs104X) that segregated with AM, retinal dystrophy, myopia, brain anomalies, and polydactyly in a family and a nonconservative missense mutation (c.278A→G, p.E93G) in a highly conserved base in another family. MR imaging and tractography in the c.226del2 proband revealed a primary brain developmental disorder affecting thalamostriatal and callosal pathways, also present in the affected grandmother. Using in situ hybridization in human embryos, we demonstrate expression of BMP4 in optic vesicle, developing retina and lens, pituitary region, and digits strongly supporting BMP4 as a causative gene for AM, pituitary, and poly/syndactyly. Because BMP4 interacts with HH signaling genes in animals, we evaluated gene expression in human embryos and demonstrate cotemporal and cospatial expression of BMP4 and HH signaling genes. We also identified four cases, some of whom had retinal dystrophy, with “low-penetrant” mutations in both BMP4 and HH signaling genes: SHH (Sonic Hedgehog) or PTCH1 (Patched). We propose that BMP4 is a major gene for AM and/or retinal dystrophy and brain anomalies and may be a candidate gene for myopia and poly/syndactyly. Our finding of low-penetrant variants in BMP4 and HH signaling partners is suggestive of an interaction between the two pathways in humans. PMID:18252212

  19. Ptpn11 Deletion in A Novel Cartilage Cell Causes Metachondromatosis by Activating Hedgehog Signaling

    PubMed Central

    Yang, Wentian; Wang, Jianguo; Moore, Douglas C.; Liang, Haipei; Dooner, Mark; Wu, Qian; Terek, Richard; Chen, Qian; Ehrlich, Michael G.; Quesenberry, Peter J.; Neel, Benjamin G.

    2013-01-01

    SHP2, encoded by PTPN11, is required for survival, proliferation and differentiation of various cell types1,2. Germ line activating mutations in PTPN11 cause Noonan Syndrome, while somatic PTPN11 mutations cause childhood myeloproliferative disease and contribute to some solid tumors. Recently, heterozygous inactivating mutations in PTPN11 were found in metachondromatosis, a rare inherited disorder featuring multiple exostoses, endochondromas, joint destruction and bony deformities3,4. The detailed pathogenesis of this disorder has remained unclear. Here, we used a conditional knockout allele (Ptpn11fl) and Cre recombinase (Cre) transgenic mice to delete Ptpn11 specifically in monocytes, macrophages and osteoclasts (lysozyme M-Cre; LysMCre) or in cathepsin K (Ctsk)-expressing cells, previously thought to be osteoclasts. LysMCre;Ptpn11fl/fl mice had mild osteopetrosis. Surprisingly, however, CtskCre;Ptpn11fl/fl mice developed features strikingly similar to metachondromatosis. Lineage tracing revealed a novel population of Ctsk-Cre-expressing cells in the “Perichondrial Groove of Ranvier” that display markers and functional properties consistent with mesenchymal progenitors. Chondroid neoplasms arose from these cells and showed decreased Erk activation, increased Indian Hedgehog (Ihh) and Parathyroid hormone-related protein (Pthrp) expression and excessive proliferation. Shp2-deficient chondroprogenitors had decreased FGF-evoked Erk activation and enhanced Ihh and Pthrp expression, whereas FGFR or MEK inhibitor treatment of chondroid cells increased Ihh and Pthrp expression. Most importantly, Smoothened inhibitor treatment ameliorated metachondromatosis features in CtskCre;Ptpn11fl/fl mice. Thus, in contrast to its pro-oncogenic role in hematopoietic and epithelial cells, Ptpn11 is a tumor suppressor in cartilage, acting via an FGFR/MEK/ERK-dependent pathway in a novel progenitor cell population to prevent excessive Ihh production. PMID:23863940

  20. Activation of sonic hedgehog signaling attenuates oxidized low-density lipoprotein-stimulated brain microvascular endothelial cells dysfunction in vitro.

    PubMed

    Jiang, Xiu-Long; Chen, Ting; Zhang, Xu

    2015-01-01

    The study was performed to investigate the role of sonic hedgehog (SHH) in the oxidized low-density lipoprotein (oxLDL)-induced blood-brain barrier (BBB) disruption. The primary mouse brain microvascular endothelial cells (MBMECs) were exposed to oxLDL. The results indicated that treatment of MBMECs with oxLDL decreased the cell viability, and oxidative stress was involved in oxLDL-induce MBMECs dysfunction with increasing intracellular ROS and MDA formation as well as decreasing NO release and eNOS mRNA expression. In addition, SHH signaling components, such as SHH, Smo and Gli1, mRNA and protein levels were significantly decreased after incubation with increasing concentrations of oxLDL. Treatment with oxLDL alone or SHH loss-of-function significantly increased the permeability of MBMECs, and overexpression of SHH attenuated oxLDL-induced elevation of permeability in MBMECs. Furthermore, SHH gain-of-function could reverse oxLDL-induced apoptosis through inhibition caspase3 and caspase8 levels in MBMECs. Taken together, these results demonstrated that the suppression of SHH in MBMECs might contribute to the oxLDL-induced disruption of endothelial barrier. However, the overexpression of SHH could reverse oxLDL-induced endothelial cells dysfunction in vitro.

  1. Targeting Hedgehog signaling pathway and autophagy overcomes drug resistance of BCR-ABL-positive chronic myeloid leukemia.

    PubMed

    Zeng, Xian; Zhao, Hui; Li, Yubin; Fan, Jiajun; Sun, Yun; Wang, Shaofei; Wang, Ziyu; Song, Ping; Ju, Dianwen

    2015-01-01

    The frontline tyrosine kinase inhibitor (TKI) imatinib has revolutionized the treatment of patients with chronic myeloid leukemia (CML). However, drug resistance is the major clinical challenge in the treatment of CML. The Hedgehog (Hh) signaling pathway and autophagy are both related to tumorigenesis, cancer therapy, and drug resistance. This study was conducted to explore whether the Hh pathway could regulate autophagy in CML cells and whether simultaneously regulating the Hh pathway and autophagy could induce cell death of drug-sensitive or -resistant BCR-ABL(+) CML cells. Our results indicated that pharmacological or genetic inhibition of Hh pathway could markedly induce autophagy in BCR-ABL(+) CML cells. Autophagic inhibitors or ATG5 and ATG7 silencing could significantly enhance CML cell death induced by Hh pathway suppression. Based on the above findings, our study demonstrated that simultaneously inhibiting the Hh pathway and autophagy could markedly reduce cell viability and induce apoptosis of imatinib-sensitive or -resistant BCR-ABL(+) cells. Moreover, this combination had little cytotoxicity in human peripheral blood mononuclear cells (PBMCs). Furthermore, this combined strategy was related to PARP cleavage, CASP3 and CASP9 cleavage, and inhibition of the BCR-ABL oncoprotein. In conclusion, this study indicated that simultaneously inhibiting the Hh pathway and autophagy could potently kill imatinib-sensitive or -resistant BCR-ABL(+) cells, providing a novel concept that simultaneously inhibiting the Hh pathway and autophagy might be a potent new strategy to overcome CML drug resistance.

  2. Combined activity of the two Gli2 genes of zebrafish play a major role in Hedgehog signaling during zebrafish neurodevelopment.

    PubMed

    Ke, Zhiyuan; Kondrichin, Igor; Gong, Zhiyuan; Korzh, Vladimir

    2008-02-01

    It has been proposed that the downstream mediator of the evolutionarily conserved Hedgehog pathway Gli2 plays a relatively minor role in neural development of zebrafish. The second gli2 of zebrafish, gli2b, is expressed in the neural plate and the central nervous system. Our comparative analysis of the developmental role of gli2/gli2b demonstrate a major role of the two Gli2s in mediating Hh signaling. The Gli2s play an early Hh-independent repressor role in the maintenance of neural progenitors and an Hh-dependent activating role during cell differentiation in the floor plate, branchial motor neurons, and sensory neurons. Our analysis of Gli2b loss-of-function using antisense morpholino oligonucleotides indicates that the functions of the two Gli2s diverged in evolution. Gli2b acts in cell proliferation and plays an early role in the hindbrain within a regulatory cascade involving Notch and Ngn1, as well as a role as specific activator in rhombomere 4.

  3. Activation of sonic hedgehog signaling attenuates oxidized low-density lipoprotein-stimulated brain microvascular endothelial cells dysfunction in vitro.

    PubMed

    Jiang, Xiu-Long; Chen, Ting; Zhang, Xu

    2015-01-01

    The study was performed to investigate the role of sonic hedgehog (SHH) in the oxidized low-density lipoprotein (oxLDL)-induced blood-brain barrier (BBB) disruption. The primary mouse brain microvascular endothelial cells (MBMECs) were exposed to oxLDL. The results indicated that treatment of MBMECs with oxLDL decreased the cell viability, and oxidative stress was involved in oxLDL-induce MBMECs dysfunction with increasing intracellular ROS and MDA formation as well as decreasing NO release and eNOS mRNA expression. In addition, SHH signaling components, such as SHH, Smo and Gli1, mRNA and protein levels were significantly decreased after incubation with increasing concentrations of oxLDL. Treatment with oxLDL alone or SHH loss-of-function significantly increased the permeability of MBMECs, and overexpression of SHH attenuated oxLDL-induced elevation of permeability in MBMECs. Furthermore, SHH gain-of-function could reverse oxLDL-induced apoptosis through inhibition caspase3 and caspase8 levels in MBMECs. Taken together, these results demonstrated that the suppression of SHH in MBMECs might contribute to the oxLDL-induced disruption of endothelial barrier. However, the overexpression of SHH could reverse oxLDL-induced endothelial cells dysfunction in vitro. PMID:26722472

  4. Protecting the hedgerow: p53 and hedgehog pathway interactions.

    PubMed

    Ho, Louisa; Alman, Benjamin

    2010-02-01

    A common environment for the Hedgehog (Subfamily: erinaceinae) is a row of shrubs and trees often used on farms for enclosing or separating fields, called a hedgerow. Maintenance of a continuous shrub border is important for shielding crops from weather damage, but also provides an ideal protective habitat for the hedgehog. Similar to its mammalian counterpart, the Hedgehog (Hh) signalling pathway requires a controlled environment to regulate proper functioning of the cell. When allowed to run wild, constitutive activation of the Hh pathway results in tumorigenesis in different tissues types, including brain, skin and cartilage. With an additional loss of p53 tumor suppressor activity, an increase in tumor incidence, size and metastasis have been observed. p53 has a number of functions that can suppress tumor formation and growth in most, if not all Hh-related cancers, such as the inhibition of cell cycle progression and cell survival. Furthermore, increasing evidence of an interaction between p53 and Hedgehog signalling pathways suggests a critical role for the tumor suppressor activity of p53 in "protecting the hedgerow".

  5. Duration of culture and sonic hedgehog signaling differentially specify PV versus SST cortical interneuron fates from embryonic stem cells.

    PubMed

    Tyson, Jennifer A; Goldberg, Ethan M; Maroof, Asif M; Xu, Qing; Petros, Timothy J; Anderson, Stewart A

    2015-04-01

    Medial ganglionic eminence (MGE)-derived GABAergic cortical interneurons (cINs) consist of multiple subtypes that are involved in many cortical functions. They also have a remarkable capacity to migrate, survive and integrate into cortical circuitry after transplantation into postnatal cortex. These features have engendered considerable interest in generating distinct subgroups of interneurons from pluripotent stem cells (PSCs) for the study of interneuron fate and function, and for the development of cell-based therapies. Although advances have been made, the capacity to generate highly enriched pools of subgroup fate-committed interneuron progenitors from PSCs has remained elusive. Previous studies have suggested that the two main MGE-derived interneuron subgroups--those expressing somatostatin (SST) and those expressing parvalbumin (PV)--are specified in the MGE from Nkx2.1-expressing progenitors at higher or lower levels of sonic hedgehog (Shh) signaling, respectively. To further explore the role of Shh and other factors in cIN fate determination, we generated a reporter line such that Nkx2.1-expressing progenitors express mCherry and postmitotic Lhx6-expressing MGE-derived interneurons express GFP. Manipulations of Shh exposure and time in culture influenced the subgroup fates of ESC-derived interneurons. Exposure to higher Shh levels, and collecting GFP-expressing precursors at 12 days in culture, resulted in the strongest enrichment for SST interneurons over those expressing PV, whereas the strongest enrichment for PV interneurons was produced by lower Shh and by collecting mCherry-expressing cells after 17 days in culture. These findings confirm that fate determination of cIN subgroups is crucially influenced by Shh signaling, and provide a system for the further study of interneuron fate and function. PMID:25804737

  6. Bufalin suppresses cancer stem-like cells in gemcitabine-resistant pancreatic cancer cells via Hedgehog signaling

    PubMed Central

    Wang, Haiyong; Ning, Zhouyu; Li, Yingyi; Zhu, Xiaoyan; Meng, Zhiqiang

    2016-01-01

    Cancer stem cells (CSCs) are important in cancer, as these cells possess enhanced tumor-forming capabilities and are resistant to current anticancer therapies. Agents with the ability to suppress CSCs are likely to provide novel opportunities for combating tumor proliferation and metastasis. The present study aimed to evaluate the effects of bufalin on pancreatic CSCs in vivo and in vitro. Using a serum-free suspension culture, tumor spheres were enriched in a gemcitabine-resistant human pancreatic cancer cell line, which had a higher percentage of CSCs, and western blotting, flow cytometry, and colony and tumor formation assays were used to demonstrate that these sphere cells exhibited CSC characteristics. Using these cancer stem-like cells as a model, the present study examined the effect of bufalin on pancreatic CSCs. It was demonstrated that bufalin inhibited the number of tumor spheres, and western blotting and immunohistochemical assays showed that the expression levels of CD24 and epithelial specific antigen (ESA) were downregulated by bufalin. Furthermore, in a subcutaneous xenograft model of implanted gemcitabine-resistant MiaPaCa2 cells, bufalin inhibited tumor growth and prolonged the duration of tumor formation. Additionally, the expression levels of CD24 and ESA were inhibited in the bufalin-treated mice. Notably, in another cancer model injected with tumor cells via the tail vein, fewer metastatic lesions were detected in the group in which tumor cells were pretreated with bufalin in vitro, compared with those without pretreatment. Of note, the Hedgehog (Hh) signaling pathway was found to be inhibited in the bufalin-treated cells. Taken together, these results suggested that bufalin suppressed pancreatic CSCs in gemcitabine-resistant MiaPaCa2 cells, and the Hh signaling pathway may be involved in this process. PMID:27432228

  7. Hedgehog inhibits β-catenin activity in synovial joint development and osteoarthritis

    PubMed Central

    Rockel, Jason S.; Yu, Chunying; Whetstone, Heather; Craft, April M.; Reilly, Katherine; Ma, Henry; Tsushima, Hidetoshi; Puviindran, Vijitha; Al-Jazrawe, Mushriq; Keller, Gordon M.; Alman, Benjamin A.

    2016-01-01

    Both the WNT/β-catenin and hedgehog signaling pathways are important in the regulation of limb development, chondrocyte differentiation, and degeneration of articular cartilage in osteoarthritis (OA). It is not clear how these signaling pathways interact in interzone cell differentiation and synovial joint morphogenesis. Here, we determined that constitutive activation of hedgehog signaling specifically within interzone cells induces joint morphological changes by selectively inhibiting β-catenin–induced Fgf18 expression. Stabilization of β-catenin or treatment with FGF18 rescued hedgehog-induced phenotypes. Hedgehog signaling induced expression of a dominant negative isoform of TCF7L2 (dnTCF7L2) in interzone progeny, which may account for the selective regulation of β-catenin target genes observed. Knockdown of TCF7L2 isoforms in mouse chondrocytes rescued hedgehog signaling–induced Fgf18 downregulation, while overexpression of the human dnTCF7L2 orthologue (dnTCF4) in human chondrocytes promoted the expression of catabolic enzymes associated with OA. Similarly, expression of dnTCF4 in human chondrocytes positively correlated with the aggrecanase ADAMTS4. Consistent with our developmental findings, activation of β-catenin also attenuated hedgehog-induced or surgically induced articular cartilage degeneration in mouse models of OA. Thus, our results demonstrate that hedgehog inhibits selective β-catenin target gene expression to direct interzone progeny fates and articular cartilage development and disease. Moreover, agents that increase β-catenin activity have the potential to therapeutically attenuate articular cartilage degeneration as part of OA. PMID:27018594

  8. Drosophila homeodomain-interacting protein kinase inhibits the Skp1-Cul1-F-box E3 ligase complex to dually promote Wingless and Hedgehog signaling.

    PubMed

    Swarup, Sharan; Verheyen, Esther M

    2011-06-14

    Drosophila Homeodomain-interacting protein kinase (Hipk) has been shown to regulate in vivo, the stability of Armadillo, the transcriptional effector of Wingless signaling. The Wingless pathway culminates in the stabilization of Armadillo that, in the absence of signaling, is sequentially phosphorylated, polyubiquitinated and degraded. Loss-of-function clones for hipk result in reduced stabilized Armadillo, whereas overexpression of hipk elevates Armadillo levels to promote Wingless-responsive target gene expression. Here, we show that overexpression of hipk can suppress the effects of negative regulators of Armadillo to prevent its degradation in the wing imaginal disc. Hipk acts to stabilize Armadillo by impeding the function of the E3 ubiquitin ligase Skp1-Cul1-F-box (SCF)(Slimb), thereby inhibiting Armadillo ubiquitination and subsequent degradation. Vertebrate Hipk2 displays a similar ability to prevent β-catenin ubiquitination in a functionally conserved mechanism. We find that Hipk's ability to inhibit SCF(Slimb)-mediated ubiquitination is not restricted to Armadillo and extends to other substrates of SCF(Slimb), including the Hedgehog signaling effector Ci. Thus, similar to casein kinase 1 and glycogen synthase kinase 3, Hipk dually regulates both Wingless and Hedgehog signaling by controlling the stability of their respective signaling effectors, but it is the first kinase to our knowledge identified that promotes the stability of both Armadillo and Ci.

  9. Stepwise, non-adherent differentiation of human pluripotent stem cells to generate basal forebrain cholinergic neurons via hedgehog signaling.

    PubMed

    Crompton, Lucy A; Byrne, Meg L; Taylor, Hannah; Kerrigan, Talitha L; Bru-Mercier, Gilles; Badger, Jennifer L; Barbuti, Peter A; Jo, Jihoon; Tyler, Sue J; Allen, Shelley J; Kunath, Tilo; Cho, Kwangwook; Caldwell, Maeve A

    2013-11-01

    Basal forebrain cholinergic neurons (bfCNs) which provide innervation to the hippocampus and cortex, are required for memory and learning, and are primarily affected in Alzheimer's Disease (AD), resulting in related cognitive decline. Therefore generation of a source of bfCNs from human pluripotent stem cells (hPSCs) is crucial for in vitro disease modeling and development of novel AD therapies. In addition, for the advancement of regenerative approaches there is a requirement for an accurate developmental model to study the neurogenesis and survival of this population. Here we demonstrate the efficient production of bfCNs, using a novel embryoid body (EB) based non-adherent differentiation (NAdD) protocol. We establish a specific basal forebrain neural stem cell (NSC) phenotype via expression of the basal forebrain transcription factors NKX2.1 and LHX8, as well as the general forebrain marker FOXG1. We present evidence that this lineage is achieved via recapitulation of embryonic events, with induction of intrinsic hedgehog signaling, through the use of a 3D non-adherent differentiation system. This is the first example of hPSC-derived basal forebrain-like NSCs, which are scalable via self-renewal in prolonged culture. Furthermore upon terminal differentiation these basal forebrain-like NSCs generate high numbers of cholinergic neurons expressing the specific markers ChAT, VACht and ISL1. These hPSC-derived bfCNs possess characteristics that are crucial in a model to study AD related cholinergic neuronal loss in the basal forebrain. Examples are expression of the therapeutic target p75(NTR), the release of acetylcholine, and demonstration of a mature, and functional electrophysiological profile. In conclusion, this work provides a renewable source of human functional bfCNs applicable for studying AD specifically in the cholinergic system, and also provides a model of the key embryonic events in human bfCN development. PMID:24013066

  10. Structure–Activity Relationships for Side Chain Oxysterol Agonists of the Hedgehog Signaling Pathway

    PubMed Central

    2012-01-01

    Oxysterols (OHCs) are byproducts of cholesterol oxidation that are known to activate the Hedeghog (Hh) signaling pathway. While OHCs that incorporate hydroxyl groups throughout the scaffold are known, those that act as agonists of Hh signaling primarily contain a single hydroxyl on the alkyl side chain. We sought to further explore how side chain hydroxylation patterns affect oxysterol-mediated Hh activation, by performing a structure–activity relationship study on a series of synthetic OHCs. The most active analogue, 23(R)-OHC (35), demonstrated potent activation of Hh signaling in two Hh-dependent cell lines (EC50 values 0.54–0.65 μM). In addition, OHC 35 was approximately 3-fold selective for the Hh pathway as compared to the liver X receptor, a nuclear receptor that is also activated by endogenous OHCs. Finally, 35 induced osteogenic differentiation and osteoblast formation in cultured cells, indicating functional agonism of the Hh pathway. PMID:24900386

  11. Cell-autonomous activation of Hedgehog signaling inhibits brown adipose tissue development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although recent studies have shown that brown adipose tissue (BAT) arises from progenitor cells that also give rise to skeletal muscle, the developmental signals that control the formation of BAT remain largely unknown. Here, we show that brown preadipocytes possess primary cilia and can respond to ...

  12. Pituitary Adenylate Cyclase Activating Polypeptide (PACAP) Pathway Is Induced by Mechanical Load and Reduces the Activity of Hedgehog Signaling in Chondrogenic Micromass Cell Cultures.

    PubMed

    Juhász, Tamás; Szentléleky, Eszter; Somogyi, Csilla Szűcs; Takács, Roland; Dobrosi, Nóra; Engler, Máté; Tamás, Andrea; Reglődi, Dóra; Zákány, Róza

    2015-01-01

    Pituitary adenylate cyclase activating polypeptide (PACAP) is a neurohormone exerting protective function during various stress conditions either in mature or developing tissues. Previously we proved the presence of PACAP signaling elements in chicken limb bud-derived chondrogenic cells in micromass cell cultures. Since no data can be found if PACAP signaling is playing any role during mechanical stress in any tissues, we aimed to investigate its contribution in mechanotransduction during chondrogenesis. Expressions of the mRNAs of PACAP and its major receptor, PAC1 increased, while that of other receptors, VPAC1, VPAC2 decreased upon mechanical stimulus. Mechanical load enhanced the expression of collagen type X, a marker of hypertrophic differentiation of chondrocytes and PACAP addition attenuated this elevation. Moreover, exogenous PACAP also prevented the mechanical load evoked activation of hedgehog signaling: protein levels of Sonic and Indian Hedgehogs and Gli1 transcription factor were lowered while expressions of Gli2 and Gli3 were elevated by PACAP application during mechanical load. Our results suggest that mechanical load activates PACAP signaling and exogenous PACAP acts against the hypertrophy inducing effect of mechanical load. PMID:26230691

  13. Pituitary Adenylate Cyclase Activating Polypeptide (PACAP) Pathway Is Induced by Mechanical Load and Reduces the Activity of Hedgehog Signaling in Chondrogenic Micromass Cell Cultures

    PubMed Central

    Juhász, Tamás; Szentléleky, Eszter; Szűcs Somogyi, Csilla; Takács, Roland; Dobrosi, Nóra; Engler, Máté; Tamás, Andrea; Reglődi, Dóra; Zákány, Róza

    2015-01-01

    Pituitary adenylate cyclase activating polypeptide (PACAP) is a neurohormone exerting protective function during various stress conditions either in mature or developing tissues. Previously we proved the presence of PACAP signaling elements in chicken limb bud-derived chondrogenic cells in micromass cell cultures. Since no data can be found if PACAP signaling is playing any role during mechanical stress in any tissues, we aimed to investigate its contribution in mechanotransduction during chondrogenesis. Expressions of the mRNAs of PACAP and its major receptor, PAC1 increased, while that of other receptors, VPAC1, VPAC2 decreased upon mechanical stimulus. Mechanical load enhanced the expression of collagen type X, a marker of hypertrophic differentiation of chondrocytes and PACAP addition attenuated this elevation. Moreover, exogenous PACAP also prevented the mechanical load evoked activation of hedgehog signaling: protein levels of Sonic and Indian Hedgehogs and Gli1 transcription factor were lowered while expressions of Gli2 and Gli3 were elevated by PACAP application during mechanical load. Our results suggest that mechanical load activates PACAP signaling and exogenous PACAP acts against the hypertrophy inducing effect of mechanical load. PMID:26230691

  14. Hedgehog Is a Positive Regulator of FGF Signalling during Embryonic Tracheal Cell Migration

    PubMed Central

    Butí, Elisenda; Mesquita, Duarte; Araújo, Sofia J.

    2014-01-01

    Cell migration is a widespread and complex process that is crucial for morphogenesis and for the underlying invasion and metastasis of human cancers. During migration, cells are steered toward target sites by guidance molecules that induce cell direction and movement through complex intracellular mechanisms. The spatio-temporal regulation of the expression of these guidance molecules is of extreme importance for both normal morphogenesis and human disease. One way to achieve this precise regulation is by combinatorial inputs of different transcription factors. Here we used Drosophila melanogaster mutants with migration defects in the ganglionic branches of the tracheal system to further clarify guidance regulation during cell migration. By studying the cellular consequences of overactivated Hh signalling, using ptc mutants, we found that Hh positively regulates Bnl/FGF levels during embryonic stages. Our results show that Hh modulates cell migration non-autonomously in the tissues surrounding the action of its activity. We further demonstrate that the Hh signalling pathway regulates bnl expression via Stripe (Sr), a zinc-finger transcription factor with homology to the Early Growth Response (EGR) family of vertebrate transcription factors. We propose that Hh modulates embryonic cell migration by participating in the spatio-temporal regulation of bnl expression in a permissive mode. By doing so, we provide a molecular link between the activation of Hh signalling and increased chemotactic responses during cell migration. PMID:24651658

  15. Immunohistochemical evaluation of hedgehog signalling in epithelial/mesenchymal interactions in squamous cell carcinoma transformation: a pilot study.

    PubMed

    Gonzalez, Ana Cristina; Ferreira, Maira; Ariel, Tamires; Reis, Sílvia Regina; Andrade, Zilton; Peixoto Medrado, Alena

    2016-03-01

    Precancerous lesions have been studied because of their carcinogenic potential and their association with squamous cell carcinoma (SCC) has been reported. In the tumour microenvironment, the processes of angiogenesis and tissue remodelling are regulated by a family of proteins (Hedgehog) described as being able to modulate epithelial/mesenchymal interactions. The objective of this study was to perform a comparative study of precancerous lesions and SCCs by immunohistochemistry for the presence of Sonic, Gli2, SMO and Patched proteins, members of the Hedgehog pathway. Sixteen cases diagnosed as actinic cheilitis associated with SCC were compared to normal oral mucosa. The sections were subjected to immunohistochemistry and the positively stained cells were counted by morphometric analysis. There was a significant progressive increase in expression of all proteins of the Hedgehog pathway, both in the epithelium and in the connective tissue, when sections of normal mucosa, dysplasia and carcinoma were compared (P < 0.05). Thus, one may suggest that the Hedgehog pathway in tumour transformation influences SCC, and more studies should be conducted to expand the understanding of the role of these proteins in neoplastic transformation. PMID:26947270

  16. EFCAB7 and IQCE regulate Hedgehog signaling by tethering the EVC-EVC2 complex to the base of primary cilia

    PubMed Central

    Pusapati, Ganesh V.; Hughes, Casey E; Dorn, Karolin V.; Zhang, Dapeng; Sugianto, Priscilla; Aravind, L.; Rohatgi, Rajat

    2014-01-01

    The Hedgehog (Hh) pathway depends on primary cilia in vertebrates, but the signaling machinery within cilia remains incompletely defined. We report the identification of a complex between two ciliary proteins, EFCAB7 and IQCE, which positively regulates the Hh pathway. The EFCAB7-IQCE module anchors the EVC-EVC2 complex in a signaling microdomain at the base of cilia. EVC and EVC2 genes are mutated in Ellis van Creveld and Weyers syndromes, characterized by impaired Hh signaling in skeletal, cardiac and orofacial tissues. EFCAB7 binds to a C-terminal disordered region in EVC2 that is deleted in Weyers patients. EFCAB7 depletion mimics the Weyers cellular phenotype— the mis-localization of EVC-EVC2 within cilia and impaired activation of the transcription factor GLI2. Evolutionary analysis suggests that emergence of these complexes might have been important for adaptation of an ancient organelle, the cilium, for an animal-specific signaling network. PMID:24582806

  17. Aberrant expression of Sonic hedgehog signaling in Peutz-Jeghers syndrome.

    PubMed

    Xu, Xiaoping; Su, Juan; Li, Ran; Wang, Yadong; Zeng, Di; Wu, Baoping

    2016-04-01

    The SHH signaling pathway is critical for gastrointestinal development and organic patterning, and dysregulation of SHH pathway molecules has been detected in multiple gastrointestinal neoplasms. This study investigated the role of the SHH signaling pathway in PJS. Expression of SHH, PTCH, and GLI1 was examined by real-time PCR and immunohistochemistry in 20 normal tissues and 75 colorectal lesions (25 PJPs, 25 adenomas, and 25 adenocarcinomas). Expression of SHH, PTCH, and GLI1 mRNA was higher in PJPs than in normal tissue (P < .05) and gradually increased along the PJP-adenoma-adenocarcinoma sequence (P < .05). Immunostaining indicated that SHH expression was present in 60% of PJPs, 72% of adenomas, and 84% of carcinomas, whereas 68% of PJPs, 72% of adenomas, and 88% of carcinomas exhibited cytoplasmic expression of PTCH. Moreover, high GLI1 expression was detected in 56% of PJPs, 64% of adenomas, and 80% of carcinomas; and high nuclear expression of GLI1 was observed in 8 adenomas with atypia and 15 carcinomas. Increased SHH, PTCH, and GLI1 protein correlated positively with tumor grade (P = .012, P = .003, and P = .007, respectively), tumor depth (P = .024, P = .007, and P = .01), and lymph node metastasis (P = .05, P = .015, and P = .005). This study identified aberrant expression of SHH pathway molecules in PJS, and the findings may supply a novel mechanism for the development of PJ polyps. PMID:26997450

  18. Modulation of Ciliary Phosphoinositide Content Regulates Trafficking and Sonic Hedgehog Signaling Output.

    PubMed

    Chávez, Marcelo; Ena, Sabrina; Van Sande, Jacqueline; de Kerchove d'Exaerde, Alban; Schurmans, Stéphane; Schiffmann, Serge N

    2015-08-10

    Ciliary transport is required for ciliogenesis, signal transduction, and trafficking of receptors to the primary cilium. Mutations in inositol polyphosphate 5-phosphatase E (INPP5E) have been associated with ciliary dysfunction; however, its role in regulating ciliary phosphoinositides is unknown. Here we report that in neural stem cells, phosphatidylinositol 4-phosphate (PI4P) is found in high levels in cilia whereas phosphatidylinositol (4,5)-bisphosphate (PI(4,5)P2) is not detectable. Upon INPP5E inactivation, PI(4,5)P2 accumulates at the ciliary tip whereas PI4P is depleted. This is accompanied by recruitment of the PI(4,5)P2-interacting protein TULP3 to the ciliary membrane, along with Gpr161. This results in an increased production of cAMP and a repression of the Shh transcription gene Gli1. Our results reveal the link between ciliary regulation of phosphoinositides by INPP5E and Shh regulation via ciliary trafficking of TULP3/Gpr161 and also provide mechanistic insight into ciliary alterations found in Joubert and MORM syndromes resulting from INPP5E mutations.

  19. Tetramethylpyrazine Inhibits Activation of Hepatic Stellate Cells through Hedgehog Signaling Pathways In Vitro

    PubMed Central

    Hu, Jue; Cao, Gang; Wu, Xin; Cai, Hao; Cai, Baochang

    2015-01-01

    Background and Aim. Tetramethylpyrazine (TMP), a major alkaloid isolated from Ligusticum chuanxiong, has been reported in hepatic fibrosis models. However, the action mechanism remains unclear. In the present study, effects of tetramethylpyrazine (TMP) against hepatic stellate cell (HSC) activation as well as the possible mechanisms were evaluated. Methods. Western blot assay was used to detect TMP effects on protein expression of Smo, Patched, Hhip, and Gli and to investigate the effects of TMP on Cyclin D1, Cyclin E1, CDK2, Bcl-2, Bax, and caspase expression with cyclopamine supplementation. Results. Our results showed that TMP significantly inhibits the expression of Cyclin D1, Cyclin E1, and Cyclin-dependent kinase CDK2 and changes the HSC cycle by inhibiting the proliferation of HSC. Moreover, TMP has also been shown to decrease the expression of Bcl-2 and increase the expression of Bax in HSC-T6 cells. Furthermore, TMP can inhibit the expression of connective tissue growth factor (CTGF), and the inhibitory effect was intensified after the application of joint treatment with TMP and cyclopamine. Conclusion. TMP may be an effective Hh signaling pathway inhibitor for hepatic fibrosis treatment. PMID:26380286

  20. Zebrafish mutations in Gli-mediated hedgehog signaling lead to lens transdifferentiation from the adenohypophysis anlage.

    PubMed

    Kondoh, H; Uchikawa, M; Yoda, H; Takeda, H; Furutani-Seiki, M; Karlstrom, R O

    2000-09-01

    It is known that the earliest lens marker delta-crystallin is expressed abundantly in Rathke's pouch of the chicken, suggesting a close relationship between the cell states of the adenohypophysis (pituitary) anlage and the early lens. We show here that the zebrafish midline mutants you-too (yot) and iguana (igu) develop lenses from the adenohypophysis anlage. The early adenohypophysis anlage of normal zebrafish expresses lim3 and six3 but in yot(ty119) mutants the anterior part of the anlage lacks lim3 expression, and instead produces a crystallin-expressing cell population which develops into a large lens structure expressing beta and gamma-crystallins, but is not associated with retina tissues. Among the zebrafish mutants with midline defects, midline lenses were observed in two mutant alleles of yot and an allele of igu, but not in other mutants (syu, con, smh, dtr, uml, spi and lok). Two yot mutant alleles with midline lenses likely encode dominant negative forms of the Gli2 protein which will interfere with transcriptional activation by other Gli proteins. The observation argues that overall inhibition of Shh-Gli signaling leads the adenohypophysis anlage to transdifferentiate into lens.

  1. Dosage-dependent hedgehog signals integrated with Wnt/β-catenin signaling regulate external genitalia formation as an appendicular program

    PubMed Central

    Miyagawa, Shinichi; Moon, Anne; Haraguchi, Ryuma; Inoue, Chie; Harada, Masayo; Nakahara, Chiaki; Suzuki, Kentaro; Matsumaru, Daisuke; Kaneko, Takehito; Matsuo, Isao; Yang, Lei; Taketo, Makoto M.; Iguchi, Taisen; Evans, Sylvia M.; Yamada, Gen

    2009-01-01

    Embryonic appendicular structures, such as the limb buds and the developing external genitalia, are suitable models with which to analyze the reciprocal interactions of growth factors in the regulation of outgrowth. Although several studies have evaluated the individual functions of different growth factors in appendicular growth, the coordinated function and integration of input from multiple signaling cascades is poorly understood. We demonstrate that a novel signaling cascade governs formation of the embryonic external genitalia [genital tubercle (GT)]. We show that the dosage of Shh signal is tightly associated with subsequent levels of Wnt/β-catenin activity and the extent of external genitalia outgrowth. In Shh-null mouse embryos, both expression of Wnt ligands and Wnt/β-catenin signaling activity are downregulated. β-catenin gain-of-function mutation rescues defective GT outgrowth and Fgf8 expression in Shh-null embryos. These data indicate that Wnt/β-catenin signaling in the distal urethral epithelium acts downstream of Shh signaling during GT outgrowth. The current data also suggest that Wnt/β-catenin regulates Fgf8 expression via Lef/Tcf binding sites in a 3′ conserved enhancer. Fgf8 induces phosphorylation of Erk1/2 and cell proliferation in the GT mesenchyme in vitro, yet Fgf4/8 compound-mutant phenotypes indicate dispensable functions of Fgf4/8 and the possibility of redundancy among multiple Fgfs in GT development. Our results provide new insights into the integration of growth factor signaling in the appendicular developmental programs that regulate external genitalia development. PMID:19906864

  2. Rapamycin targeting mTOR and hedgehog signaling pathways blocks human rhabdomyosarcoma growth in xenograft murine model

    SciTech Connect

    Kaylani, Samer Z.; Xu, Jianmin; Srivastava, Ritesh K.; Kopelovich, Levy; Pressey, Joseph G.; Athar, Mohammad

    2013-06-14

    Graphical abstract: Intervention of poorly differentiated RMS by rapamycin: In poorly differentiated RMS, rapamycin blocks mTOR and Hh signaling pathways concomitantly. This leads to dampening in cell cycle regulation and induction of apoptosis. This study provides a rationale for the therapeutic intervention of poorly differentiated RMS by treating patients with rapamycin alone or in combination with other chemotherapeutic agents. -- Highlights: •Rapamycin abrogates RMS tumor growth by modulating proliferation and apoptosis. •Co-targeting mTOR/Hh pathways underlie the molecular basis of effectiveness. •Reduction in mTOR/Hh pathways diminish EMT leading to reduced invasiveness. -- Abstract: Rhabdomyosarcomas (RMS) represent the most common childhood soft-tissue sarcoma. Over the past few decades outcomes for low and intermediate risk RMS patients have slowly improved while patients with metastatic or relapsed RMS still face a grim prognosis. New chemotherapeutic agents or combinations of chemotherapies have largely failed to improve the outcome. Based on the identification of novel molecular targets, potential therapeutic approaches in RMS may offer a decreased reliance on conventional chemotherapy. Thus, identification of effective therapeutic agents that specifically target relevant pathways may be particularly beneficial for patients with metastatic and refractory RMS. The PI3K/AKT/mTOR pathway has been found to be a potentially attractive target in RMS therapy. In this study, we provide evidence that rapamycin (sirolimus) abrogates growth of RMS development in a RMS xenograft mouse model. As compared to a vehicle-treated control group, more than 95% inhibition in tumor growth was observed in mice receiving parenteral administration of rapamycin. The residual tumors in rapamycin-treated group showed significant reduction in the expression of biomarkers indicative of proliferation and tumor invasiveness. These tumors also showed enhanced apoptosis

  3. Requirement for non-regulated, constitutive calcium influx in macrophage survival signaling

    SciTech Connect

    Tano, Jean-Yves; Vazquez, Guillermo

    2011-04-08

    Highlights: {yields} We examine the role of constitutive Ca{sup 2+} influx in macrophage survival. {yields} Survival signaling exhibits a mandatory requirement for constitutive Ca{sup 2+} influx. {yields} CAM/CAMKII couples constitutive Ca{sup 2+} influx to survival signaling. -- Abstract: The phosphatidylinositol-3-kinase (PI3K)/AKT axis and the Nuclear Factor kappa B (NF{kappa}B) pathway play critical roles in macrophage survival. In cells other than macrophages proper operation of those two pathways requires Ca{sup 2+} influx into the cell, but if that is the case in macrophages remains unexplored. In the present work we used THP-1-derived macrophages and a pharmacological approach to examine for the first time the role of constitutive, non-regulated Ca{sup 2+} influx in PI3K/AKT and NF{kappa}B signaling. Blocking constitutive function of Ca{sup 2+}-permeable channels with the organic channel blocker SKF96365 completely prevented phosphorylation of I{kappa}B{alpha}, AKT and its downstream target BAD in TNF{alpha}-treated macrophages. A similar effect was observed upon treating macrophages with the calmodulin (CAM) inhibitor W-7 or the calmodulin-dependent kinase II (CAMKII) inhibitor KN-62. In addition, pre-treating macrophages with SKF96365 significantly enhanced TNF{alpha}-induced apoptosis. Our findings suggest that in THP-1-derived macrophages survival signaling depends, to a significant extent, on constitutive Ca{sup 2+} influx presumably through a mechanism that involves the CAM/CAMKII axis as a coupling component between constitutive Ca{sup 2+} influx and activation of survival signaling.

  4. The PRKCI and SOX2 Oncogenes are Co-amplified and Cooperate to Activate Hedgehog Signaling in Lung Squamous Cell Carcinoma

    PubMed Central

    Justilien, Verline; Walsh, Michael P.; Ali, Syed A.; Thompson, E. Aubrey; Murray, Nicole R.; Fields, Alan P.

    2014-01-01

    SUMMARY We report that two oncogenes co-amplified on chromosome 3q26, PRKCI and SOX2, cooperate to drive a stem-like phenotype in lung squamous cell carcinoma (LSCC). PKCι phosphorylates SOX2, a master transcriptional regulator of stemness, and recruits it to the promoter of Hedgehog Acyl Transferase (HHAT), which catalyzes the rate-limiting step in Hh ligand production. PKCι-mediated SOX2 phosphorylation is required for HHAT promoter occupancy, HHAT expression, and maintenance of a stem-like phenotype. Primary LSCC tumors coordinately overexpress PKCι, SOX2, and HHAT, and require PKCι-SOX2-HHAT signaling to maintain a stem-like phenotype. Thus, PKCι and SOX2 are genetically, biochemically and functionally linked in LSCC, and together they drive tumorigenesis by establishing a cell autonomous Hh signaling axis. PMID:24525231

  5. Cross-platform expression profiling demonstrates that SV40 small tumor antigen activates Notch, Hedgehog, and Wnt signaling in human cells

    PubMed Central

    Ali-Seyed, Mohamed; Laycock, Noelani; Karanam, Suresh; Xiao, Wenming; Blair, Eric T; Moreno, Carlos S

    2006-01-01

    Background We previously analyzed human embryonic kidney (HEK) cell lines for the effects that simian virus 40 (SV40) small tumor antigen (ST) has on gene expression using Affymetrix U133 GeneChips. To cross-validate and extend our initial findings, we sought to compare the expression profiles of these cell lines using an alternative microarray platform. METHODS: We have analyzed matched cell lines with and without expression of SV40 ST using an Applied Biosystems (AB) microarray platform that uses single 60-mer oligonucleotides and single-color quantitative chemiluminescence for detection. RESULTS: While we were able to previously identify only 456 genes affected by ST with the Affymetrix platform, we identified 1927 individual genes with the AB platform. Additional technical replicates increased the number of identified genes to 3478 genes and confirmed the changes in 278 (61%) of our original set of 456 genes. Among the 3200 genes newly identified as affected by SV40 ST, we confirmed 20 by QRTPCR including several components of the Wnt, Notch, and Hedgehog signaling pathways, consistent with SV40 ST activation of these developmental pathways. While inhibitors of Notch activation had no effect on cell survival, cyclopamine had a potent killing effect on cells expressing SV40 ST. CONCLUSIONS: These data show that SV40 ST expression alters cell survival pathways to sensitize cells to the killing effect of Hedgehog pathway inhibitors. PMID:16522205

  6. Sonic hedgehog signaling coordinates the proliferation and differentiation of neural stem/progenitor cells by regulating cell cycle kinetics during development of the neocortex.

    PubMed

    Komada, Munekazu

    2012-06-01

    Sonic hedgehog (Shh) acts as a morphogen in normal development of various vertebrate tissues and organs. Shh signaling is essential for patterning and cell-fate specification, particularly in the central nervous system. Shh signaling plays different roles depending on its concentration, area, and timing of exposure. During the development of the neocortex, a low level of Shh is expressed in the neural stem/progenitor cells as well as in mature neurons in the dorsal telencephalon. Shh signaling in neocortex development has been shown to regulate cell cycle kinetics of radial glial cells and intermediate progenitor cells, thereby maintaining the proliferation, survival and differentiation of neurons in the neocortex. During the development of the telencephalon, endogenous Shh signaling is involved in the transition of slow-cycling neural stem cells to fast-cycling neural progenitor cells. It seems that high-level Shh signaling in the ventral telencephalon is essential for ventral specification, while low-level Shh signaling in the dorsal telencephalon plays important roles in the fine-tuning of cell cycle kinetics. The Shh levels and multiple functions of Shh signaling are important for proper corticogenesis in the developing brain. The present paper discusses the roles of Shh signaling in the proliferation and differentiation of neural stem/progenitor cells.

  7. Use of a Conditional Ubr5 Mutant Allele to Investigate the Role of an N-End Rule Ubiquitin-Protein Ligase in Hedgehog Signalling and Embryonic Limb Development

    PubMed Central

    Kinsella, Elaine; Dora, Natalie; Mellis, David; Lettice, Laura; Deveney, Paul

    2016-01-01

    Hedgehog (Hh) signalling is a potent regulator of cell fate and function. While much is known about the events within a Hh-stimulated cell, far less is known about the regulation of Hh-ligand production. Drosophila Hyperplastic Discs (Hyd), a ubiquitin-protein ligase, represents one of the few non-transcription factors that independently regulates both hh mRNA expression and pathway activity. Using a murine embryonic stem cell system, we revealed that shRNAi of the mammalian homologue of hyd, Ubr5, effectively prevented retinoic-acid-induced Sonic hedgehog (Shh) expression. We next investigated the UBR5:Hh signalling relationship in vivo by generating and validating a mouse bearing a conditional Ubr5 loss-of-function allele. Conditionally deleting Ubr5 in the early embryonic limb-bud mesenchyme resulted in a transient decrease in Indian hedgehog ligand expression and decreased Hh pathway activity, around E13.5. Although Ubr5-deficient limbs and digits were, on average, shorter than control limbs, the effects were not statistically significant. Hence, while loss of UBR5 perturbed Hedgehog signalling in the developing limb, there were no obvious morphological defects. In summary, we report the first conditional Ubr5 mutant mouse and provide evidence for a role for UBR5 in influencing Hh signalling, but are uncertain to whether the effects on Hedgehog signaling were direct (cell autonomous) or indirect (non-cell-autonomous). Elaboration of the cellular/molecular mechanism(s) involved may help our understanding on diseases and developmental disorders associated with aberrant Hh signalling. PMID:27299863

  8. Use of a Conditional Ubr5 Mutant Allele to Investigate the Role of an N-End Rule Ubiquitin-Protein Ligase in Hedgehog Signalling and Embryonic Limb Development.

    PubMed

    Kinsella, Elaine; Dora, Natalie; Mellis, David; Lettice, Laura; Deveney, Paul; Hill, Robert; Ditzel, Mark

    2016-01-01

    Hedgehog (Hh) signalling is a potent regulator of cell fate and function. While much is known about the events within a Hh-stimulated cell, far less is known about the regulation of Hh-ligand production. Drosophila Hyperplastic Discs (Hyd), a ubiquitin-protein ligase, represents one of the few non-transcription factors that independently regulates both hh mRNA expression and pathway activity. Using a murine embryonic stem cell system, we revealed that shRNAi of the mammalian homologue of hyd, Ubr5, effectively prevented retinoic-acid-induced Sonic hedgehog (Shh) expression. We next investigated the UBR5:Hh signalling relationship in vivo by generating and validating a mouse bearing a conditional Ubr5 loss-of-function allele. Conditionally deleting Ubr5 in the early embryonic limb-bud mesenchyme resulted in a transient decrease in Indian hedgehog ligand expression and decreased Hh pathway activity, around E13.5. Although Ubr5-deficient limbs and digits were, on average, shorter than control limbs, the effects were not statistically significant. Hence, while loss of UBR5 perturbed Hedgehog signalling in the developing limb, there were no obvious morphological defects. In summary, we report the first conditional Ubr5 mutant mouse and provide evidence for a role for UBR5 in influencing Hh signalling, but are uncertain to whether the effects on Hedgehog signaling were direct (cell autonomous) or indirect (non-cell-autonomous). Elaboration of the cellular/molecular mechanism(s) involved may help our understanding on diseases and developmental disorders associated with aberrant Hh signalling. PMID:27299863

  9. Indian hedgehog signaling and the role of graft tension in tendon-to-bone healing: Evaluation in a rat ACL reconstruction model.

    PubMed

    Carbone, Andrew; Carballo, Camila; Ma, Richard; Wang, Hongsheng; Deng, Xianghua; Dahia, Chitra; Rodeo, Scott

    2016-04-01

    The structure and composition of the native enthesis is not recapitulated following tendon-to-bone repair. Indian Hedgehog (IHH) signaling has recently been shown to be important in enthesis development in a mouse model but no studies have evaluated IHH signaling in a healing model. Fourteen adult male rats underwent ACL reconstruction using a flexor tendon graft. Rats were assigned to two groups based on whether or not they received 0N or 10N of pre-tension of the graft. Specimens were evaluated at 3 and 6 weeks post-operatively using immunohistochemistry for three different protein markers of IHH signaling. Quantitative analysis of staining area and intensity using custom software demonstrated that IHH signaling was active in interface tissue formed at the healing tendon-bone interface. We also found increased staining area and intensity of IHH signaling proteins at 3 weeks in animals that received a pre-tensioned tendon graft. No significant differences were seen between the 3-week and 6-week time points. Our data suggests that the IHH signaling pathway is active during the tendon-bone healing process and appears to be mechanosensitive, as pre-tensioning of the graft at the time of surgery resulted in increased IHH signaling at three weeks. PMID:26447744

  10. Blockade of Hedgehog Signaling Synergistically Increases Sensitivity to Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Non-Small-Cell Lung Cancer Cell Lines.

    PubMed

    Bai, Xiao-Yan; Zhang, Xu-Chao; Yang, Su-Qing; An, She-Juan; Chen, Zhi-Hong; Su, Jian; Xie, Zhi; Gou, Lan-Ying; Wu, Yi-Long

    2016-01-01

    Aberrant activation of the hedgehog (Hh) signaling pathway has been implicated in the epithelial-to-mesenchymal transition (EMT) and cancer stem-like cell (CSC) maintenance; both processes can result in tumor progression and treatment resistance in several types of human cancer. Hh cooperates with the epidermal growth factor receptor (EGFR) signaling pathway in embryogenesis. We found that the Hh signaling pathway was silenced in EGFR-TKI-sensitive non-small-cell lung cancer (NSCLC) cells, while it was inappropriately activated in EGFR-TKI-resistant NSCLC cells, accompanied by EMT induction and ABCG2 overexpression. Upregulation of Hh signaling through extrinsic SHH exposure downregulated E-cadherin expression and elevated Snail and ABCG2 expression, resulting in gefitinib tolerance (P < 0.001) in EGFR-TKI-sensitive cells. Blockade of the Hh signaling pathway using the SMO antagonist SANT-1 restored E-cadherin expression and downregulate Snail and ABCG2 in EGFR-TKI-resistant cells. A combination of SANT-1 and gefitinib markedly inhibited tumorigenesis and proliferation in EGFR-TKI-resistant cells (P < 0.001). These findings indicate that hyperactivity of Hh signaling resulted in EGFR-TKI resistance, by EMT introduction and ABCG2 upregulation, and blockade of Hh signaling synergistically increased sensitivity to EGFR-TKIs in primary and secondary resistant NSCLC cells. E-cadherin expression may be a potential biomarker of the suitability of the combined application of an Hh inhibitor and EGFR-TKIs in EGFR-TKI-resistant NSCLCs. PMID:26943330

  11. Combination of cyclopamine and tamoxifen promotes survival and migration of mcf-7 breast cancer cells--interaction of hedgehog-gli and estrogen receptor signaling pathways.

    PubMed

    Sabol, Maja; Trnski, Diana; Uzarevic, Zvonimir; Ozretic, Petar; Musani, Vesna; Rafaj, Maja; Cindric, Mario; Levanat, Sonja

    2014-01-01

    Hedgehog-Gli (Hh-Gli) signaling pathway is one of the new molecular targets found upregulated in breast tumors. Estrogen receptor alpha (ERα) signaling has a key role in the development of hormone-dependent breast cancer. We aimed to investigate the effects of inhibiting both pathways simultaneously on breast cancer cell survival and the potential interactions between these two signaling pathways. ER-positive MCF-7 cells show decreased viability after treatment with cyclopamine, a Hh-Gli pathway inhibitor, as well as after tamoxifen (an ERα inhibitor) treatment. Simultaneous treatment with cyclopamine and tamoxifen on the other hand, causes short-term survival of cells, and increased migration. We found upregulated Hh-Gli signaling under these conditions and protein profiling revealed increased expression of proteins involved in cell proliferation and migration. Therefore, even though Hh-Gli signaling seems to be a good potential target for breast cancer therapy, caution must be advised, especially when combining therapies. In addition, we also show a potential direct interaction between the Shh protein and ERα in MCF-7 cells. Our data suggest that the Shh protein is able to activate ERα independently of the canonical Hh-Gli signaling pathway. Therefore, this may present an additional boost for ER-positive cells that express Shh, even in the absence of estrogen.

  12. Combination of Cyclopamine and Tamoxifen Promotes Survival and Migration of MCF-7 Breast Cancer Cells – Interaction of Hedgehog-Gli and Estrogen Receptor Signaling Pathways

    PubMed Central

    Uzarevic, Zvonimir; Ozretic, Petar; Musani, Vesna; Rafaj, Maja; Cindric, Mario; Levanat, Sonja

    2014-01-01

    Hedgehog-Gli (Hh-Gli) signaling pathway is one of the new molecular targets found upregulated in breast tumors. Estrogen receptor alpha (ERα) signaling has a key role in the development of hormone-dependent breast cancer. We aimed to investigate the effects of inhibiting both pathways simultaneously on breast cancer cell survival and the potential interactions between these two signaling pathways. ER-positive MCF-7 cells show decreased viability after treatment with cyclopamine, a Hh-Gli pathway inhibitor, as well as after tamoxifen (an ERα inhibitor) treatment. Simultaneous treatment with cyclopamine and tamoxifen on the other hand, causes short-term survival of cells, and increased migration. We found upregulated Hh-Gli signaling under these conditions and protein profiling revealed increased expression of proteins involved in cell proliferation and migration. Therefore, even though Hh-Gli signaling seems to be a good potential target for breast cancer therapy, caution must be advised, especially when combining therapies. In addition, we also show a potential direct interaction between the Shh protein and ERα in MCF-7 cells. Our data suggest that the Shh protein is able to activate ERα independently of the canonical Hh-Gli signaling pathway. Therefore, this may present an additional boost for ER-positive cells that express Shh, even in the absence of estrogen. PMID:25503972

  13. Mycobacteria-responsive sonic hedgehog signaling mediates programmed death-ligand 1- and prostaglandin E2-induced regulatory T cell expansion

    PubMed Central

    Holla, Sahana; Stephen-Victor, Emmanuel; Prakhar, Praveen; Sharma, Meenu; Saha, Chaitrali; Udupa, Vibha; Kaveri, Srinivas V.; Bayry, Jagadeesh; Balaji, Kithiganahalli Narayanaswamy

    2016-01-01

    CD4+CD25+FoxP3+ regulatory T cells (Tregs) are exploited by mycobacteria to subvert the protective host immune responses. The Treg expansion in the periphery requires signaling by professional antigen presenting cells and in particularly dendritic cells (DC). However, precise molecular mechanisms by which mycobacteria instruct Treg expansion via DCs are not established. Here we demonstrate that mycobacteria-responsive sonic hedgehog (SHH) signaling in human DCs leads to programmed death ligand-1 (PD-L1) expression and cyclooxygenase (COX)-2-catalyzed prostaglandin E2 (PGE2) that orchestrate mycobacterial infection-induced expansion of Tregs. While SHH-responsive transcription factor GLI1 directly arbitrated COX-2 transcription, specific microRNAs, miR-324-5p and miR-338-5p, which target PD-L1 were downregulated by SHH signaling. Further, counter-regulatory roles of SHH and NOTCH1 signaling during mycobacterial-infection of human DCs was also evident. Together, our results establish that Mycobacterium directs a fine-balance of host signaling pathways and molecular regulators in human DCs to expand Tregs that favour immune evasion of the pathogen. PMID:27080341

  14. Network modeling of TGFβ signaling in hepatocellular carcinoma epithelial-to-mesenchymal transition reveals joint Sonic hedgehog and Wnt pathway activation

    PubMed Central

    Steinway, Steven Nathaniel; Zañudo, Jorge Gomez Tejeda; Ding, Wei; Rountree, Carl Bart; Feith, David J.; Loughran, Thomas P.; Albert, Reka

    2014-01-01

    Epithelial-to-mesenchymal transition (EMT) is a developmental process hijacked by cancer cells to leave the primary tumor site, invade surrounding tissue, and establish distant metastases. A hallmark of EMT is the loss of E-cadherin expression, and one major signal for the induction of EMT is transforming growth factor beta (TGFβ, which is dysregulated in up to 40% of hepatocellular carcinoma (HCC). We have constructed an EMT network of 70 nodes and 135 edges by integrating the signaling pathways involved in developmental EMT and known dysregulations in invasive HCC. We then used discrete dynamic modeling to understand the dynamics of the EMT network driven by TGFβ. Our network model recapitulates known dysregulations during the induction of EMT and predicts the activation of the Wnt and Sonic hedgehog (SHH) signaling pathways during this process. We show, across multiple murine (P2E and P2M) and human HCC cell lines (Huh7, PLC/PRF/5, HLE, and HLF), that the TGFβ signaling axis is a conserved driver of mesenchymal phenotype HCC and confirm that Wnt and SHH signaling are induced in these cell lines. Furthermore, we identify by network analysis eight regulatory feedback motifs that stabilize the EMT process and show that these motifs involve cross-talk among multiple major pathways. Our model will be useful in identifying potential therapeutic targets for the suppression of EMT, invasion and metastasis in HCC. PMID:25189528

  15. Regulation of Patched by Sonic Hedgehog in the Developing Neural Tube

    NASA Astrophysics Data System (ADS)

    Marigo, Valeria; Tabin, Clifford J.

    1996-09-01

    Ventral cell fates in the central nervous system are induced by Sonic hedgehog, a homolog of hedgehog, a secreted Drosophila protein. In the central nervous system, Sonic hedgehog has been identified as the signal inducing floor plate, motor neurons, and dopaminergic neurons. Sonic hedgehog is also involved in the induction of ventral cell type in the developing somites. ptc is a key gene in the Drosophila hedgehog signaling pathway where it is involved in transducing the hedgehog signal and is also a transcriptional target of the signal. PTC, a vertebrate homolog of this Drosophila gene, is genetically downstream of Sonic hedgehog (Shh) in the limb bud. We analyze PTC expression during chicken neural and somite development and find it expressed in all regions of these tissues known to be responsive to Sonic hedgehog signal. As in the limb bud, ectopic expression of Sonic hedgehog leads to ectopic induction of PTC in the neural tube and paraxial mesoderm. This conservation of regulation allows us to use PTC as a marker for Sonic hedgehog response. The pattern of PTC expression suggests that Sonic hedgehog may play an inductive role in more dorsal regions of the neural tube than have been previously demonstrated. Examination of the pattern of PTC expression also suggests that PTC may act in a negative feedback loop to attenuate hedgehog signaling.

  16. Regulation of patched by sonic hedgehog in the developing neural tube.

    PubMed Central

    Marigo, V; Tabin, C J

    1996-01-01

    Ventral cell fates in the central nervous system are induced by Sonic hedgehog, a homolog of hedgehog, a secreted Drosophila protein. In the central nervous system, Sonic hedgehog has been identified as the signal inducing floor plate, motor neurons, and dopaminergic neurons. Sonic hedgehog is also involved in the induction of ventral cell type in the developing somites. ptc is a key gene in the Drosophila hedgehog signaling pathway where it is involved in transducing the hedgehog signal and is also a transcriptional target of the signal. PTC, a vertebrate homolog of this Drosophila gene, is genetically downstream of Sonic hedgehog (Shh) in the limb bud. We analyze PTC expression during chicken neural and somite development and find it expressed in all regions of these tissues known to be responsive to Sonic hedgehog signal. As in the limb bud, ectopic expression of Sonic hedgehog leads to ectopic induction of PTC in the neural tube and paraxial mesoderm. This conservation of regulation allows us to use PTC as a marker for Sonic hedgehog response. The pattern of PTC expression suggests that Sonic hedgehog may play an inductive role in more dorsal regions of the neural tube than have been previously demonstrated. Examination of the pattern of PTC expression also suggests that PTC may act in a negative feedback loop to attenuate hedgehog signaling. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8790332

  17. Induction of the unfolded protein response by constitutive G-protein signaling in rod photoreceptor cells.

    PubMed

    Wang, Tian; Chen, Jeannie

    2014-10-17

    Phototransduction is a G-protein signal transduction cascade that converts photon absorption to a change in current at the plasma membrane. Certain genetic mutations affecting the proteins in the phototransduction cascade cause blinding disorders in humans. Some of these mutations serve as a genetic source of "equivalent light" that activates the cascade, whereas other mutations lead to amplification of the light response. How constitutive phototransduction causes photoreceptor cell death is poorly understood. We showed that persistent G-protein signaling, which occurs in rod arrestin and rhodopsin kinase knock-out mice, caused a rapid and specific induction of the PERK pathway of the unfolded protein response. These changes were not observed in the cGMP-gated channel knock-out rods, an equivalent light condition that mimics light-stimulated channel closure. Thus transducin signaling, but not channel closure, triggers rapid cell death in light damage caused by constitutive phototransduction. Additionally, we show that in the albino light damage model cell death was not associated with increase in global protein ubiquitination or unfolded protein response induction. Taken together, these observations provide novel mechanistic insights into the cell death pathway caused by constitutive phototransduction and identify the unfolded protein response as a potential target for therapeutic intervention.

  18. Cloning of zebrafish nkx6.2 and a comprehensive analysis of the conserved transcriptional response to Hedgehog/Gli signaling in the zebrafish neural tube.

    PubMed

    Guner, Burcu; Karlstrom, Rolf O

    2007-04-01

    Sonic Hedgehog (Shh) signaling helps pattern the vertebrate neural tube, in part by regulating the dorsal/ventral expression of a number of homeodomain containing transcription factors. These Hh responsive genes have been divided into two classes, with Class II genes being activated by Hh signaling and Class I genes being repressed by Hh signaling. While the transcriptional response to varying Hh levels is well defined in chick and mouse, it is only partially described in zebrafish, despite the fact that zebrafish has emerged as a powerful genetic system for the study of neural patterning. To better characterize the Hh response in the zebrafish neural tube, we cloned the zebrafish Class II Hh target genes nkx2.9 and nkx6.2. We then analyzed the expression of a number of Class I and Class II Hh responsive genes in wild type, Hh mutant, and Hh over-expressing zebrafish embryos. We show that expression of Class I and Class II genes is highly conserved in the vertebrate neural tube. Further, ventral-most Class II gene expression was completely lost in all Hh pathway mutants analyzed, indicating high levels of Hh signaling are blocked in all of these mutants. In contrast, more dorsally expressed genes were variably affected in different Hh pathway mutants, indicating mid-levels of Hh signaling are differentially affected. This comprehensive expression study provides an important tool for the characterization of Hh signaling in zebrafish and provides a sensitive assay for determining the degree to which newly identified zebrafish mutants affect Hh signaling.

  19. Characterization of the human oncogene SCL/TAL1 interrupting locus (Stil) mediated Sonic hedgehog (Shh) signaling transduction in proliferating mammalian dopaminergic neurons

    SciTech Connect

    Sun, Lei; Carr, Aprell L.; Li, Ping; Lee, Jessica; McGregor, Mary; Li, Lei

    2014-07-11

    Highlights: • Stil is a human oncogene that is conserved in vertebrate species. • Stil functions in the Shh pathway in mammalian cells. • The expression of Stil is required for mammalian dopaminergic cell proliferation. - Abstract: The human oncogene SCL/TAL1 interrupting locus (Stil) is highly conserved in all vertebrate species. In humans, the expression of Stil is involved in cancer cell survival, apoptosis and proliferation. In this research, we investigated the roles of Stil expression in cell proliferation of mammalian dopaminergic (DA) PC12 cells. Stil functions through the Sonic hedgehog (Shh) signal transduction pathway. Co-immunoprecipitation tests revealed that STIL interacts with Shh downstream components, which include SUFU and GLI1. By examining the expression of Stil, Gli1, CyclinD2 (cell-cycle marker) and PCNA (proliferating cell nuclear antigen), we found that up-regulation of Stil expression (transfection with overexpression plasmids) increased Shh signaling transduction and PC12 cell proliferation, whereas down-regulation of Stil expression (by shRNA) inhibited Shh signaling transduction, and thereby decreased PC12 cell proliferation. Transient transfection of PC12 cells with Stil knockdown or overexpression plasmids did not affect PC12 cell neural differentiation, further indicating the specific roles of Stil in cell proliferation. The results from this research suggest that Stil may serve as a bio-marker for neurological diseases involved in DA neurons, such as Parkinson’s disease.

  20. Inhibition of CK2α Down-Regulates Hedgehog/Gli Signaling Leading to a Reduction of a Stem-Like Side Population in Human Lung Cancer Cells

    PubMed Central

    Zhang, Shulin; Wang, Yucheng; Mao, Jian-Hua; Hsieh, David; Kim, Il-Jin; Hu, Li-Min; Xu, Zhidong; Long, Hao; Jablons, David M.; You, Liang

    2012-01-01

    Protein kinase CK2 is frequently elevated in a variety of human cancers. The Hedgehog (Hh) signaling pathway has been implicated in stem cell maintenance, and its aberrant activation has been indicated in several types of cancer, including lung cancer. In this study, we show that CK2 is positively involved in Hh/Gli signaling in lung cancer cell lines A549 and H1299. First, we found a correlation between CK2α and Gli1 mRNA levels in 100 primary lung cancer tissues. Down-regulation of Gli1 expression and transcriptional activity were demonstrated after the silencing of CK2α in lung cancer cells. In addition, CK2α siRNA down-regulated the expression of Hh target genes. Furthermore, two small-molecule CK2α inhibitors led to a dose-dependent inhibition of Gli1 expression and transcriptional activity in lung cancer cells. Reversely, forced over-expression of CK2α resulted in an increase both in Gli1 expression and transcriptional activity in A549 cells. Finally, the inhibition of Hh/Gli by CK2α siRNA led to a reduction of a cancer stem cell-like side population that shows higher ABCG2 expression level. Thus, we report that the inhibition of CK2α down-regulates Hh/Gli signaling and subsequently reduces stem-like side population in human lung cancer cells. PMID:22768056

  1. The Hedgehog protein family.

    PubMed

    Bürglin, Thomas R

    2008-01-01

    The Hedgehog (Hh) pathway is one of the fundamental signal transduction pathways in animal development and is also involved in stem-cell maintenance and carcinogenesis. The hedgehog (hh) gene was first discovered in Drosophila, and members of the family have since been found in most metazoa. Hh proteins are composed of two domains, an amino-terminal domain HhN, which has the biological signal activity, and a carboxy-terminal autocatalytic domain HhC, which cleaves Hh into two parts in an intramolecular reaction and adds a cholesterol moiety to HhN. HhC has sequence similarity to the self-splicing inteins, and the shared region is termed Hint. New classes of proteins containing the Hint domain have been discovered recently in bacteria and eukaryotes, and the Hog class, of which Hh proteins comprise one family, is widespread throughout eukaryotes. The non-Hh Hog proteins have carboxy-terminal domains (the Hog domain) highly similar to HhC, although they lack the HhN domain, and instead have other amino-terminal domains. Hog proteins are found in many protists, but the Hh family emerged only in early metazoan evolution. HhN is modified by cholesterol at its carboxyl terminus and by palmitate at its amino terminus in both flies and mammals. The modified HhN is released from the cell and travels through the extracellular space. On binding its receptor Patched, it relieves the inhibition that Patched exerts on Smoothened, a G-protein-coupled receptor. The resulting signaling cascade converges on the transcription factor Cubitus interruptus (Ci), or its mammalian counterparts, the Gli proteins, which activate or repress target genes.

  2. New Constitutively Active Phytochromes Exhibit Light-Independent Signaling Activity1[OPEN

    PubMed Central

    Jeong, A-Reum; Lee, Si-Seok; Han, Yun-Jeong; Shin, Ah-Young; Baek, Ayoung; Ahn, Taeho; Kim, Min-Gon; Kim, Young Soon; Lee, Keun Woo; Nagatani, Akira

    2016-01-01

    Plant phytochromes are photoreceptors that mediate a variety of photomorphogenic responses. There are two spectral photoisomers, the red light-absorbing Pr and far-red light-absorbing Pfr forms, and the photoreversible transformation between the two forms is important for the functioning of phytochromes. In this study, we isolated a Tyr-268-to-Val mutant of Avena sativa phytochrome A (AsYVA) that displayed little photoconversion. Interestingly, transgenic plants of AsYVA showed light-independent phytochrome signaling with a constitutive photomorphogenic (cop) phenotype that is characterized by shortened hypocotyls and open cotyledons in the dark. In addition, the corresponding Tyr-303-to-Val mutant of Arabidopsis (Arabidopsis thaliana) phytochrome B (AtYVB) exhibited nuclear localization and interaction with phytochrome-interacting factor 3 (PIF3) independently of light, conferring a constitutive photomorphogenic development to its transgenic plants, which is comparable to the first constitutively active version of phytochrome B (YHB; Tyr-276-to-His mutant). We also found that chromophore ligation was required for the light-independent interaction of AtYVB with PIF3. Moreover, we demonstrated that AtYVB did not exhibit phytochrome B activity when it was localized in the cytosol by fusion with the nuclear export signal and that AsYVA exhibited the full activity of phytochrome A when localized in the nucleus by fusion with the nuclear localization signal. Furthermore, the corresponding Tyr-269-to-Val mutant of Arabidopsis phytochrome A (AtYVA) exhibited similar cop phenotypes in transgenic plants to AsYVA. Collectively, these results suggest that the conserved Tyr residues in the chromophore-binding pocket play an important role during the Pr-to-Pfr photoconversion of phytochromes, providing new constitutively active alleles of phytochromes by the Tyr-to-Val mutation. PMID:27325667

  3. Hedgehog-glioma-associated oncogene homolog-1 signaling in colon cancer cells and its role in the celecoxib-mediated anti-cancer effect.

    PubMed

    Wang, Hongtao; Ke, Fei; Zheng, Jie

    2014-11-01

    Hedgehog (Hh) signaling is activated in numerous malignant tumors, but its role in human colorectal cancer remains uncertain. Celecoxib, a selective cyclooxygenase-2 inhibitor, has been shown to exhibit chemoprevention in colorectal cancer, however, the effects of celecoxib on Hh signaling remain unknown. The current study presents an evaluation of Hh signaling in colon cancer cell lines and the effects of celecoxib in vitro. Active Hh signaling was observed in LoVo and HT-29 cells, with particularly high levels in the LoVo cells. However, Hh signaling activity was absent in HCT-116 cells. Quantitative polymerase chain reaction indicated that the expression of Hh receptor patched homolog 1 (PTCH1) was absent in the LoVo cells, but that they exhibited high levels of glioma-associated oncogene homolog-1 (GLI1) expression, while high expression levels of PTCH1 and low expression levels of smoothened (SMO) and GLI1 were observed in the HCT-116 cells. The HCT-116 cells were extremely sensitive to celecoxib, whereas the LoVo cells were resistant to the anticancer effect of the drug. Celecoxib downregulated the expression of GLI1 in the HCT-116 and HT-29 cells, but did not change the expression of GLI1 in the LoVo cells. The results presented in this study indicated that the anticancer effect of celecoxib is selective in colon cancer cells; celecoxib may target cancer cells via the SMO-independent modulation of GLI1 activity, and Hh signaling may be significant in maintaining the malignant state of LoVo cells. These findings may aid in improving our understanding of the carcinogenesis of colon cancer and the development of novel approaches for the targeted therapy of this disease. PMID:25295109

  4. Constitutive IFNα/β signaling maintains expression of signaling intermediaries for efficient cytokine responses.

    PubMed

    Messina, Nicole L; Clarke, Christopher J P; Johnstone, Ricky W

    2016-01-01

    Interferons (IFNs) are a family of immunoregulatory cytokines with important roles in anti-viral and anti-tumor responses. Type I and II IFNs bind distinct receptors and are associated with different stages of the immune response. There is however, considerable crosstalk between these two cytokines with enhancement of IFNγ responses following IFNα/β priming and loss of IFNα/β receptor (IFNAR) resulting in diminished IFNγ responses. In this study, we sought to define the mechanism of crosstalk between the type I and II IFNs. Our previous reports demonstrated reduced expression of the canonically activated transcription factor signal transducer and activator of transcription (STAT)1, in cells lacking the IFNAR α chain (IFNAR1). Therefore, we used microarray analysis to determine whether reconstitution of STAT1 in IFNAR1-deficient cells was sufficient to restore IFNγ responses. We identified several biological pathways, including the MHC class I antigen presentation pathway, in which STAT1 reconstitution was able to significantly rescue IFNγ-mediated gene regulation in Ifnar1 (-/-) cells. Notably, we also found that in addition to low basal expression of STAT1, cells lacking the IFNAR1 also had aberrant expression of multiple other transcription factors and signaling intermediaries. The studies described herein demonstrate that basal and regulated expression of signaling intermediaries is a mechanism for crosstalk between cytokines including type I and II IFNs. PMID:27512617

  5. Effect of methacrylic acid beads on the sonic hedgehog signaling pathway and macrophage polarization in a subcutaneous injection mouse model.

    PubMed

    Lisovsky, Alexandra; Zhang, David K Y; Sefton, Michael V

    2016-08-01

    Poly(methacrylic acid-co-methyl methacrylate) (MAA) beads promote a vascular regenerative response when used in diabetic wound healing. Previous studies reported that MAA beads modulated the expression of sonic hedgehog (Shh) and inflammation related genes in diabetic wounds. The aim of this work was to follow up on these observations in a subcutaneous injection model to study the host response in the absence of the confounding factors of diabetic wound healing. In this model, MAA beads improved vascularization in healthy mice of both sexes compared to control poly(methyl methacrylate) (MM) beads, with a stronger effect seen in males than females. MAA-induced vessels were perfusable, as evidenced from the CLARITY-processed images. In Shh-Cre-eGFP/Ptch1-LacZ non-diabetic transgenic mice, the increased vessel formation was accompanied by a higher density of cells expressing GFP (Shh) and β-Gal (patched 1, Ptch1) suggesting MAA enhanced the activation of the Shh pathway. Ptch1 is the Shh receptor and a target of the pathway. MAA beads also modulated the inflammatory cell infiltrate in CD1 mice: more neutrophils and more macrophages were noted with MAA relative to MM beads at days 1 and 7, respectively. In addition, MAA beads biased macrophages towards a MHCII-CD206+ ("M2") polarization state. This study suggests that the Shh pathway and an altered inflammatory response are two elements of the complex mechanism whereby MAA-based biomaterials effect vascular regeneration. PMID:27264502

  6. Sonic Hedgehog (SHH) Promotes the Differentiation of Mouse Cochlear Neural Progenitors via the Math1–Brn3.1 Signaling pathway in vitro

    PubMed Central

    Hu, Xiaohua; Huang, Jianmin; Feng, Ling; Fukudome, Shinji; Hamajima, Yuki; Lin, Jizhen

    2009-01-01

    Sonic hedgehog (SHH) is essential for the development of the cochlear duct that harbors the organ of Corti. However, little is known about the molecular signaling pathway through which SHH promotes the development of the organ of Corti, especially cochlear sensory epithelial cells. In this study, we demonstrated that SHH contributes to the differentiation of cochlear neural progenitors (CNPs), which are derived from the postnatal day 1 organ of Corti in mice. Addition of SHH to CNPs increased the formation of epithelial cell islands, simultaneously activated the expression of Math1 that is a transcription factor for the initial differentiation of auditory hair cells. The increased expression of Math1 then regulated the promoter activity of Brn3.1, another transcription factor that controls the further differentiation and survival of auditory hair cells. Taken together, our data suggest that SHH plays an important role in the promotion of auditory hair cell differentiation via the Math1-Brn3.1 signaling pathway. PMID:19908278

  7. Targeted mutation of the talpid3 gene in zebrafish reveals its conserved requirement for ciliogenesis and Hedgehog signalling across the vertebrates.

    PubMed

    Ben, Jin; Elworthy, Stone; Ng, Ashley Shu Mei; van Eeden, Freek; Ingham, Philip W

    2011-11-01

    Using zinc-finger nuclease-mediated mutagenesis, we have generated mutant alleles of the zebrafish orthologue of the chicken talpid3 (ta3) gene, which encodes a centrosomal protein that is essential for ciliogenesis. Animals homozygous for these mutant alleles complete embryogenesis normally, but manifest a cystic kidney phenotype during the early larval stages and die within a month of hatching. Elimination of maternally derived Ta3 activity by germline replacement resulted in embryonic lethality of ta3 homozygotes. The phenotype of such maternal and zygotic (MZta3) mutant zebrafish showed strong similarities to that of chick ta3 mutants: absence of primary and motile cilia as well as aberrant Hedgehog (Hh) signalling, the latter manifest by the expanded domains of engrailed and ptc1 expression in the somites, reduction of nkx2.2 expression in the neural tube, symmetric pectoral fins, cyclopic eyes and an ectopic lens. GFP-tagged Gli2a localised to the basal bodies in the absence of the primary cilia and western blot analysis showed that Gli2a protein is aberrantly processed in MZta3 embryos. Zygotic expression of ta3 largely rescued the effects of maternal depletion, but the motile cilia of Kupffer's vesicle remained aberrant, resulting in laterality defects. Our findings underline the importance of the primary cilium for Hh signaling in zebrafish and reveal the conservation of Ta3 function during vertebrate evolution.

  8. Lycium barbarum Polysaccharides Protect against Trimethyltin Chloride-Induced Apoptosis via Sonic Hedgehog and PI3K/Akt Signaling Pathways in Mouse Neuro-2a Cells

    PubMed Central

    Zhao, Wanyun; Pan, Xiaoqi; Li, Tao; Zhang, Changchun; Shi, Nian

    2016-01-01

    Trimethyltin chloride (TMT) is a classic neurotoxicant that can cause severe neurodegenerative diseases. Some signaling pathways involving cell death play pivotal roles in the central nervous system. In this study, the role of Sonic Hedgehog (Shh) and PI3K/Akt pathways in TMT-induced apoptosis and protective effect of Lycium barbarum polysaccharides (LBP) on mouse neuro-2a (N2a) cells were investigated. Results showed that TMT treatment significantly enhanced apoptosis, upregulated proapoptotic Bax, downregulated antiapoptotic Bcl-2 expression, and increased caspase-3 activity in a dose-dependent manner in N2a cells. TMT induced oxidative stress in cells, performing reactive oxygen species (ROS) and malondialdehyde (MDA) excessive generation, and superoxide dismutase (SOD) activity reduction. TMT significantly decreased phosphorylated glycogen synthase kinase-3β (GSK-3β) and inhibited Shh and PI3K/Akt pathways. However, the addition of LBP upregulated GSK-3β phosphorylation, activated Shh and PI3K/Akt pathways, and eventually reduced apoptosis and oxidative stress caused by TMT. The interaction between Shh and PI3K/Akt pathways was clarified by specific PI3K inhibitor LY294002 or Shh inhibitor GDC-0449. Moreover, LY294002 and GDC-0449 pretreatment both induced phosphorylated GSK-3β downregulation and significantly promoted apoptosis induced by TMT. These results suggest that LBP could reduce TMT-induced N2a cells apoptosis by regulating GSK-3β phosphorylation, Shh, and PI3K/Akt signaling pathways. PMID:27143997

  9. Hedgehog signaling is a novel therapeutic target in tamoxifen-resistant breast cancer aberrantly activated by PI3K/AKT pathway.

    PubMed

    Ramaswamy, Bhuvaneswari; Lu, Yuanzhi; Teng, Kun-yu; Nuovo, Gerard; Li, Xiaobai; Shapiro, Charles L; Majumder, Sarmila

    2012-10-01

    Endocrine resistance is a major challenge in the management of estrogen receptor (ER)-positive breast cancers. Although multiple mechanisms leading to endocrine resistance have been proposed, the poor outcome of patients developing resistance to endocrine therapy warrants additional studies. Here we show that noncanonical Hedgehog (Hh) signaling is an alternative growth promoting mechanism that is activated in tamoxifen-resistant tumors. Importantly, phosphoinositide 3-kinase inhibitor/protein kinase B (PI3K/AKT) pathway plays a key role in regulating Hh signaling by protecting key components of this pathway from proteasomal degradation. The levels of Hh-signaling molecules SMO and GLI1 and the targets were significantly elevated in tamoxifen-resistant MCF-7 cells and T47D cells. Serial passage of the resistant cells in mice resulted in aggressive tumors that metastasized to distant organs with concurrent increases in Hh marker expression and epithelial mesenchymal transition. RNAi-mediated depletion of SMO or GLI1 in the resistant cells resulted in reduced proliferation, clonogenic survival and delayed G(1)-S transition. Notably, treatment of resistant cells with PI3K inhibitors decreased SMO and GLI1 protein levels and activity that was rescued upon blocking GSK3β and proteasomal degradation. Furthermore, treatment of tamoxifen-resistant xenografts with anti-Hh compound GDC-0449 blocked tumor growth in mice. Importantly, high GLI1 expression correlated inversely with disease-free and overall survival in a cohort of 315 patients with breast cancer. In summary, our results describe a signaling event linking PI3K/AKT pathway with Hh signaling that promotes tamoxifen resistance. Targeting Hh pathway alone or in combination with PI3K/AKT pathway could therefore be a novel therapeutic option in treating endocrine-resistant breast cancer.

  10. Homeodomains, Hedgehogs, and Happiness.

    PubMed

    Scott, Matthew P

    2016-01-01

    Developmental biologists have had a spectacular quarter century of discoveries, building on many decades of work earlier, discovering molecular, cellular, and genetic mechanisms that underlie the magical process by which an egg becomes a plant or animal. Among the discoveries were homeodomains, DNA-binding domains that allow transcription factors to recognize their target genes, and the Hedgehog signaling pathway, which is used in many organs and tissues for communication among cells. The experience of unveiling the mechanisms and molecules connected to both of these findings has been remarkable, joyful, difficult, and a time of great teamwork and collaboration within and between laboratory groups. More than ever it is possible to discern the evolutionary processes, and their mechanisms, that led to the diversity of life on earth. A huge amount of work remains to be done to obtain a broad understanding of what happened and how development works.

  11. Homeodomains, Hedgehogs, and Happiness.

    PubMed

    Scott, Matthew P

    2016-01-01

    Developmental biologists have had a spectacular quarter century of discoveries, building on many decades of work earlier, discovering molecular, cellular, and genetic mechanisms that underlie the magical process by which an egg becomes a plant or animal. Among the discoveries were homeodomains, DNA-binding domains that allow transcription factors to recognize their target genes, and the Hedgehog signaling pathway, which is used in many organs and tissues for communication among cells. The experience of unveiling the mechanisms and molecules connected to both of these findings has been remarkable, joyful, difficult, and a time of great teamwork and collaboration within and between laboratory groups. More than ever it is possible to discern the evolutionary processes, and their mechanisms, that led to the diversity of life on earth. A huge amount of work remains to be done to obtain a broad understanding of what happened and how development works. PMID:26969987

  12. Targeting of the signal transducer Smo links microRNA-326 to the oncogenic Hedgehog pathway in CD34+ CML stem/progenitor cells.

    PubMed

    Babashah, Sadegh; Sadeghizadeh, Majid; Hajifathali, Abbas; Tavirani, Mostafa Rezaei; Zomorod, Mina Soufi; Ghadiani, Mojtaba; Soleimani, Masoud

    2013-08-01

    Aberrant expression and function of microRNAs (miRNAs) in leukemia have added a new layer of complexity to the understanding of development and progression of the disease state. However, their targeting of specific signaling pathways responsible for the maintenance and survival properties of leukemic stem cell (LSC) still remains to be further clarified. Hedgehog (Hh) signaling, a highly conserved developmental pathway, has been proven as a functional pathway for LSCs, and loss of this pathway impairs the development of BCR-ABL-induced chronic myeloid leukemia (CML) and depletes CML stem cells. Here, we revealed that upregulation of the Hh smoothened (Smo) signal transducer was associated with reduced expression of miR-326 in the CD34(+) cells from a group of patients with CML at diagnosis. Additionally, overexpression of miR-326 led to downregulation of Smo, resulted in decreased cell proliferation and elevated rate of apoptosis in CML CD34(+) cells. Interestingly, restoration of Smo expression levels reversed the effect of miR-326 and rescued K562 cells from the antiproliferative effects of this miRNA. Thus, Smo appears to be an essential target of miR-326 during the pathogenesis of CML. These findings lead us to suggest that downregulation of miR-326 may be a possible mechanism for unrestricted activation of Smo signal transducer of the oncogenic Hh pathway in CML; therefore, the restoration of miR-326 expression could be of benefit in eradicating CD34(+) CML stem/progenitor cells that represent a potential source of relapse in patients suffering CML.

  13. Zinc Inhibits Hedgehog Autoprocessing

    PubMed Central

    Xie, Jian; Owen, Timothy; Xia, Ke; Singh, Ajay Vikram; Tou, Emiley; Li, Lingyun; Arduini, Brigitte; Li, Hongmin; Wan, Leo Q.; Callahan, Brian; Wang, Chunyu

    2015-01-01

    Zinc is an essential trace element with wide-ranging biological functions, whereas the Hedgehog (Hh) signaling pathway plays crucial roles in both development and disease. Here we show that there is a mechanistic link between zinc and Hh signaling. The upstream activator of Hh signaling, the Hh ligand, originates from Hh autoprocessing, which converts the Hh precursor protein to the Hh ligand. In an in vitro Hh autoprocessing assay we show that zinc inhibits Hh autoprocessing with a Ki of 2 μm. We then demonstrate that zinc inhibits Hh autoprocessing in a cellular environment with experiments in primary rat astrocyte culture. Solution NMR reveals that zinc binds the active site residues of the Hh autoprocessing domain to inhibit autoprocessing, and isothermal titration calorimetry provided the thermodynamics of the binding. In normal physiology, zinc likely acts as a negative regulator of Hh autoprocessing and inhibits the generation of Hh ligand and Hh signaling. In many diseases, zinc deficiency and elevated level of Hh ligand co-exist, including prostate cancer, lung cancer, ovarian cancer, and autism. Our data suggest a causal relationship between zinc deficiency and the overproduction of Hh ligand. PMID:25787080

  14. Hedgehog signaling pathway is active in GBM with GLI1 mRNA expression showing a single continuous distribution rather than discrete high/low clusters.

    PubMed

    Chandra, Vikas; Das, Tapojyoti; Gulati, Puneet; Biswas, Nidhan K; Rote, Sarang; Chatterjee, Uttara; Ghosh, Samarendra N; Deb, Sumit; Saha, Suniti K; Chowdhury, Anup K; Ghosh, Subhashish; Rudin, Charles M; Mukherjee, Ankur; Basu, Analabha; Dhara, Surajit

    2015-01-01

    Hedgehog (Hh) signaling pathway is a valid therapeutic target in a wide range of malignancies. We focus here on glioblastoma multiforme (GBM), a lethal malignancy of the central nervous system (CNS). By analyzing RNA-sequencing based transcriptomics data on 149 clinical cases of TCGA-GBM database we show here a strong correlation (r = 0.7) between GLI1 and PTCH1 mRNA expression--as a hallmark of the canonical Hh-pathway activity in this malignancy. GLI1 mRNA expression varied in 3 orders of magnitude among the GBM patients of the same cohort showing a single continuous distribution-unlike the discrete high/low-GLI1 mRNA expressing clusters of medulloblastoma (MB). When compared with MB as a reference, the median GLI1 mRNA expression in GBM appeared 14.8 fold lower than that of the "high-Hh" cluster of MB but 5.6 fold higher than that of the "low-Hh" cluster of MB. Next, we demonstrated statistically significant up- and down-regulation of GLI1 mRNA expressions in GBM patient-derived low-passage neurospheres in vitro by sonic hedgehog ligand-enriched conditioned media (shh-CM) and by Hh-inhibitor drug vismodegib respectively. We also showed clinically achievable dose (50 μM) of vismodegib alone to be sufficient to induce apoptosis and cell cycle arrest in these low-passage GBM neurospheres in vitro. Vismodegib showed an effect on the neurospheres, both by down-regulating GLI1 mRNA expression and by inducing apoptosis/cell cycle arrest, irrespective of their relative endogenous levels of GLI1 mRNA expression. We conclude from our study that this single continuous distribution pattern of GLI1 mRNA expression technically puts almost all GBM patients in a single group rather than discrete high- or low-clusters in terms of Hh-pathway activity. That is suggestive of therapies with Hh-pathway inhibitor drugs in this malignancy without a need for further stratification of patients on the basis of relative levels of Hh-pathway activity among them. PMID:25775002

  15. BRD4 induces cell migration and invasion in HCC cells through MMP-2 and MMP-9 activation mediated by the Sonic hedgehog signaling pathway

    PubMed Central

    WANG, YONG-HUI; SUI, XIAO-MEI; SUI, YA-NA; ZHU, QIN-WEI; YAN, KAI; WANG, LI-SHAN; WANG, FEI; ZHOU, JIA-HUA

    2015-01-01

    Hepatocellular carcinoma (HCC) is a highly aggressive form of carcinoma with poor prognosis, and HCC-associated mortality primarily occurs due to migration and invasion of HCC cells. The manipulation of epigenetic proteins, such as BRD4, has recently emerged as an alternative therapeutic strategy. The present study aimed to investigate the novel mechanism of BRD4 involvement in the migration and invasion of HCC cells. Reverse transcription-quantitative polymerase chain reaction was used to assess BRD4 mRNA expression levels in HCC cell lines. This analysis demonstrated that BRD4 was significantly overexpressed in HCC cell lines compared with a human immortalized normal liver cell line. A short hairpin RNA (shRNA) was then used to suppress BRD4 expression in HCC cells, and resulted in impaired HCC cell proliferation, migration and invasion. When the HepG2 HCC cell line was treated with recombinant human sonic hedgehog (SHH) peptide, the migration and invasion capabilities of HepG2 cells that were inhibited by BRD4 silencing were restored. BRD4 induced cell migration and invasion in HepG2 cells through the activation of matrix metalloproteinase (MMP)-2 and MMP-9, mediated by the SHH signaling pathway. Taken together, the results of the present study demonstrated the importance of BRD4 in HCC cell proliferation and metastasis. Thus, BRD4 is a potential novel target for the development of therapeutic approaches against HCC. PMID:26622824

  16. The pre-clinical absorption, distribution, metabolism and excretion properties of IPI-926, an orally bioavailable antagonist of the hedgehog signal transduction pathway.

    PubMed

    Smith, Sherri; Hoyt, Jennifer; Whitebread, Nigel; Manna, Joseph; Peluso, Marisa; Faia, Kerrie; Campbell, Veronica; Tremblay, Martin; Nair, Somarajan; Grogan, Michael; Castro, Alfredo; Campbell, Matthew; Ferguson, Jeanne; Arsenault, Brendan; Nevejans, Jylle; Carter, Bennett; Lee, John; Dunbar, Joi; McGovern, Karen; Read, Margaret; Adams, Julian; Constan, Alexander; Loewen, Gordon; Sydor, Jens; Palombella, Vito; Soglia, John

    2013-10-01

    1. IPI-926 is a novel semisynthetic cyclopamine derivative that is a potent and selective Smoothened inhibitor that blocks the hedgehog signal transduction pathway. 2. The in vivo clearance of IPI-926 is low in mouse and dog and moderate in monkey. The volume of distribution is high across species. Oral bioavailability ranges from moderate in monkey to high in mouse and dog. Predicted human clearance using simple allometry is low (24 L h(-1)), predicted volume of distribution is high (469 L) and predicted half-life is long (20 h). 3. IPI-926 is highly bound to plasma proteins and has minimal interaction with human α-1-acid glycoprotein. 4. In vitro metabolic stability ranges from stable to moderately stable. Twelve oxidative metabolites were detected in mouse, rat, dog, monkey and human liver microsome incubations and none were unique to human. 5. IPI-926 is not a potent reversible inhibitor of CYP1A2, 2C8, 2C9 or 3A4 (testosterone). IPI-926 is a moderate inhibitor of CYP2C19, 2D6 and 3A4 (midazolam) with KI values of 19, 16 and 4.5 µM, respectively. IPI-926 is both a substrate and inhibitor (IC50 = 1.9 µM) of P-glycoprotein. 6. In summary, IPI-926 has desirable pre-clinical absorption, distribution, metabolism and excretion properties. PMID:23527529

  17. Widening the mutation spectrum of EVC and EVC2: ectopic expression of Weyer variants in NIH 3T3 fibroblasts disrupts Hedgehog signaling.

    PubMed

    Valencia, Maria; Lapunzina, Pablo; Lim, Derek; Zannolli, Raffaella; Bartholdi, Deborah; Wollnik, Bernd; Al-Ajlouni, Othman; Eid, Suhair S; Cox, Helen; Buoni, Sabrina; Hayek, Joseph; Martinez-Frias, Maria L; Antonio, Perez-Aytes; Temtamy, Samia; Aglan, Mona; Goodship, Judith A; Ruiz-Perez, Victor L

    2009-12-01

    Autosomal recessive Ellis-van Creveld syndrome and autosomal dominant Weyer acrodental dysostosis are allelic conditions caused by mutations in EVC or EVC2. We performed a mutation screening study in 36 EvC cases and 3 cases of Weyer acrodental dysostosis, and identified pathogenic changes either in EVC or in EVC2 in all cases. We detected 40 independent EVC/EVC2 mutations of which 29 were novel changes in Ellis-van Creveld cases and 2 were novel mutations identified in Weyer pedigrees. Of interest one EvC patient had a T>G nucleotide substitution in intron 7 of EVC (c.940-150T>G), which creates a new donor splice site and results in the inclusion of a new exon. The T>G substitution is at nucleotide +5 of the novel 5' splice site. The three Weyer mutations occurred in the final exon of EVC2 (exon 22), suggesting that specific residues encoded by this exon are a key part of the protein. Using murine versions of EVC2 exon 22 mutations we demonstrate that the expression of a Weyer variant, but not the expression of a truncated protein that mimics an Ellis-van Creveld syndrome mutation, impairs Hedgehog signal transduction in NIH 3T3 cells in keeping with its dominant effect.

  18. Research Resource: A Reference Transcriptome for Constitutive Androstane Receptor and Pregnane X Receptor Xenobiotic Signaling.

    PubMed

    Ochsner, Scott A; Tsimelzon, Anna; Dong, Jianrong; Coarfa, Cristian; McKenna, Neil J

    2016-08-01

    The pregnane X receptor (PXR) (PXR/NR1I3) and constitutive androstane receptor (CAR) (CAR/NR1I2) members of the nuclear receptor (NR) superfamily of ligand-regulated transcription factors are well-characterized mediators of xenobiotic and endocrine-disrupting chemical signaling. The Nuclear Receptor Signaling Atlas maintains a growing library of transcriptomic datasets involving perturbations of NR signaling pathways, many of which involve perturbations relevant to PXR and CAR xenobiotic signaling. Here, we generated a reference transcriptome based on the frequency of differential expression of genes across 159 experiments compiled from 22 datasets involving perturbations of CAR and PXR signaling pathways. In addition to the anticipated overrepresentation in the reference transcriptome of genes encoding components of the xenobiotic stress response, the ranking of genes involved in carbohydrate metabolism and gonadotropin action sheds mechanistic light on the suspected role of xenobiotics in metabolic syndrome and reproductive disorders. Gene Set Enrichment Analysis showed that although acetaminophen, chlorpromazine, and phenobarbital impacted many similar gene sets, differences in direction of regulation were evident in a variety of processes. Strikingly, gene sets representing genes linked to Parkinson's, Huntington's, and Alzheimer's diseases were enriched in all 3 transcriptomes. The reference xenobiotic transcriptome will be supplemented with additional future datasets to provide the community with a continually updated reference transcriptomic dataset for CAR- and PXR-mediated xenobiotic signaling. Our study demonstrates how aggregating and annotating transcriptomic datasets, and making them available for routine data mining, facilitates research into the mechanisms by which xenobiotics and endocrine-disrupting chemicals subvert conventional NR signaling modalities. PMID:27409825

  19. Drosophila ciD encodes a hybrid Pangolin/Cubitus interruptus protein that diverts the Wingless into the Hedgehog signaling pathway.

    PubMed

    Schweizer, L; Basler, K

    1998-11-01

    The Hedgehog (Hh) and Wingless (Wg) signaling pathways play important roles in animal development. The activities of the two pathways depend on each other during Drosophila embryogenesis. In the embryonic segment, Wg is required in anterior cells to sustain Hh secretion in adjacent posterior cells. Hh input in turn is necessary for anterior cells to maintain wg expression. The Hh and Wg pathways are mediated by the transcription factors Cubitus interruptus (Ci) and Pangolin/TCF (Pan), respectively. Coincidentally, pan and ci are adjacent genes on the fourth chromosome in a head-to-head orientation. Our genetic and in situ hybridization data indicate that ciD is a mutation affecting both ci and pan. Molecular analysis revealed that the ciD allele is caused by an inversion event that swapped the promoter regions and the first exons of the two genes. The ci gene in ciD is controlled by the ubiquitous pan promoter and encodes a hybrid Ci protein that carries the N-terminal region of Pan. This domain has previously been shown to bind to the b-catenin homolog Armadillo (Arm), raising the possibility that Wg input, in addition to Hh input, modulates the activity of the hybrid CiD protein. Indeed, we found that Wg signaling induces the expression of the Hh target gene patched (ptc) in ciD animals. We provide evidence that this effect depends on the ability of the CiD protein to bind Arm. Genetic and molecular data indicate that wild-type Pan and CiD compete for binding to Arm, leading to a compromised transduction of the Wg signal in heterozygous ciD/+ animals and to a dramatic enhancement of the gain-of-function activity of CiD in homozygous mutants. Thus, the Hh and the Wg pathways are affected by the ciD mutation, and the CiD fusion protein integrates the activities of both.

  20. Intestinal cell kinase, a protein associated with endocrine-cerebro-osteodysplasia syndrome, is a key regulator of cilia length and Hedgehog signaling.

    PubMed

    Moon, Heejung; Song, Jieun; Shin, Jeong-Oh; Lee, Hankyu; Kim, Hong-Kyung; Eggenschwiller, Jonathan T; Bok, Jinwoong; Ko, Hyuk Wan

    2014-06-10

    Endocrine-cerebro-osteodysplasia (ECO) syndrome is a recessive genetic disorder associated with multiple congenital defects in endocrine, cerebral, and skeletal systems that is caused by a missense mutation in the mitogen-activated protein kinase-like intestinal cell kinase (ICK) gene. In algae and invertebrates, ICK homologs are involved in flagellar formation and ciliogenesis, respectively. However, it is not clear whether this role of ICK is conserved in mammals and how a lack of functional ICK results in the characteristic phenotypes of human ECO syndrome. Here, we generated Ick knockout mice to elucidate the precise role of ICK in mammalian development and to examine the pathological mechanisms of ECO syndrome. Ick null mouse embryos displayed cleft palate, hydrocephalus, polydactyly, and delayed skeletal development, closely resembling ECO syndrome phenotypes. In cultured cells, down-regulation of Ick or overexpression of kinase-dead or ECO syndrome mutant ICK resulted in an elongation of primary cilia and abnormal Sonic hedgehog (Shh) signaling. Wild-type ICK proteins were generally localized in the proximal region of cilia near the basal bodies, whereas kinase-dead ICK mutant proteins accumulated in the distal part of bulged ciliary tips. Consistent with these observations in cultured cells, Ick knockout mouse embryos displayed elongated cilia and reduced Shh signaling during limb digit patterning. Taken together, these results indicate that ICK plays a crucial role in controlling ciliary length and that ciliary defects caused by a lack of functional ICK leads to abnormal Shh signaling, resulting in congenital disorders such as ECO syndrome.

  1. LncRNA‐Hh Strengthen Cancer Stem Cells Generation in Twist‐Positive Breast Cancer via Activation of Hedgehog Signaling Pathway

    PubMed Central

    Zhou, Mingli; Hou, Yixuan; Yang, Guanglun; Zhang, Hailong; Tu, Gang; Du, Yan‐e; Wen, Siyang; Xu, Liyun; Tang, Xi; Tang, Shifu; Yang, Li; Cui, Xiaojiang

    2015-01-01

    Summary Cancer stem cells (CSCs) are a subpopulation of neoplastic cells with self‐renewal capacity and limitless proliferative potential as well as high invasion and migration capacity. These cells are commonly associated with epithelial‐mesenchymal transition (EMT), which is also critical for tumor metastasis. Recent studies illustrate a direct link between EMT and stemness of cancer cells. Long non‐coding RNAs (lncRNAs) have emerged as important new players in the regulation of multiple cellular processes in various diseases. To date, the role of lncRNAs in EMT‐associated CSC stemness acquisition and maintenance remains unclear. In this study, we discovered that a set of lncRNAs were dysregulated in Twist‐positive mammosphere cells using lncRNA microarray analysis. Multiple lncRNAs‐associated canonical signaling pathways were identified via bioinformatics analysis. Especially, the Shh‐GLI1 pathway associated lncRNA‐Hh, transcriptionally regulated by Twist, directly targets GAS1 to stimulate the activation of hedgehog signaling (Hh). The activated Hh increases GLI1 expression, and enhances the expression of SOX2 and OCT4 to play a regulatory role in CSC maintenance. Thus, the mammosphere‐formation efficiency (MFE) and the self‐renewal capacity in vitro, and oncogenicity in vivo in Twist‐positive breast cancer cells are elevated. lncRNA‐Hh silence in Twist‐positive breast cells attenuates the activated Shh‐GLI1 signaling and decreases the CSC‐associated SOX and OCT4 levels, thus reduces the MFE and tumorigenesis of transplanted tumor. Our results reveal that lncRNAs function as an important regulator endowing Twist‐induced EMT cells to gain the CSC‐like stemness properties. Stem Cells 2016;34:55–66 PMID:26418365

  2. ABCG2 is a Direct Transcriptional Target of Hedgehog Signaling and Involved in Stroma-Induced Drug Tolerance in Diffuse Large B-Cell Lymphoma

    PubMed Central

    Singh, Rajesh R; Kunkalla, Kranthi; Qu, Changju; Schlette, Ellen; Neelapu, Sattva S; Samaniego, Felipe; Vega, Francisco

    2011-01-01

    Successful treatment of diffuse large B-cell lymphoma (DLBCL) is frequently hindered by development of resistance to conventional chemotherapy resulting in disease relapse and high mortality. High expression of anti-apoptotic and/or drug transporter proteins induced by oncogenic signaling pathways has been implicated in the development of chemoresistance in cancer. Previously, our studies showed high expression of ATP-binding cassette drug transporter ABCG2 in DLBCL correlated inversely with disease-free and failure-free survival. In this study, we have implicated activated hedgehog (Hh) signaling pathway as a key factor behind high ABCG2 expression in DLBCL through direct upregulation of ABCG2 gene transcription. We have identified a single binding site for GLI transcription factors in the ABCG2 promoter and established its functionality using luciferase reporter, site-directed mutagenesis and chromatin-immunoprecipitation assays. Furthermore, in DLBCL tumor samples, significantly high ABCG2 and GLI1 levels were found in DLBCL tumors with lymph node involvement in comparison to DLBCL tumor cells collected from pleural and/or peritoneal effusions. This suggests a role for the stromal microenvironment in maintaining high levels of ABCG2 and GLI1. Accordingly, in vitro co-culture of DLBCL cells with HS-5 stromal cells increased ABCG2 mRNA and protein levels by paracrine activation of Hh signaling. In addition to ABCG2, co-culture of DLBCL cells with HS-5 cells also resulted in increase expression of the antiapoptotic proteins BCL2, BCL-xL and BCL2A1 and in induced chemotolerance to doxorubicin and methotrexate, drugs routinely used for the treatment of DLBCL. Similarly, activation of Hh signaling in DLBCL cell lines with recombinant Shh N-terminal peptide resulted in increased expression of BCL2 and ABCG2 associated with increased chemotolerance. Finally, functional inhibition of ABCG2 drug efflux activity with fumitremorgin (FTC) or inhibition of Hh signaling with

  3. An Ancestral Role for CONSTITUTIVE TRIPLE RESPONSE1 Proteins in Both Ethylene and Abscisic Acid Signaling.

    PubMed

    Yasumura, Yuki; Pierik, Ronald; Kelly, Steven; Sakuta, Masaaki; Voesenek, Laurentius A C J; Harberd, Nicholas P

    2015-09-01

    Land plants have evolved adaptive regulatory mechanisms enabling the survival of environmental stresses associated with terrestrial life. Here, we focus on the evolution of the regulatory CONSTITUTIVE TRIPLE RESPONSE1 (CTR1) component of the ethylene signaling pathway that modulates stress-related changes in plant growth and development. First, we compare CTR1-like proteins from a bryophyte, Physcomitrella patens (representative of early divergent land plants), with those of more recently diverged lycophyte and angiosperm species (including Arabidopsis [Arabidopsis thaliana]) and identify a monophyletic CTR1 family. The fully sequenced P. patens genome encodes only a single member of this family (PpCTR1L). Next, we compare the functions of PpCTR1L with that of related angiosperm proteins. We show that, like angiosperm CTR1 proteins (e.g. AtCTR1 of Arabidopsis), PpCTR1L modulates downstream ethylene signaling via direct interaction with ethylene receptors. These functions, therefore, likely predate the divergence of the bryophytes from the land-plant lineage. However, we also show that PpCTR1L unexpectedly has dual functions and additionally modulates abscisic acid (ABA) signaling. In contrast, while AtCTR1 lacks detectable ABA signaling functions, Arabidopsis has during evolution acquired another homolog that is functionally distinct from AtCTR1. In conclusion, the roles of CTR1-related proteins appear to have functionally diversified during land-plant evolution, and angiosperm CTR1-related proteins appear to have lost an ancestral ABA signaling function. Our study provides new insights into how molecular events such as gene duplication and functional differentiation may have contributed to the adaptive evolution of regulatory mechanisms in plants.

  4. An ancient yet flexible cis-regulatory architecture allows localized Hedgehog tuning by patched/Ptch1.

    PubMed

    Lorberbaum, David S; Ramos, Andrea I; Peterson, Kevin A; Carpenter, Brandon S; Parker, David S; De, Sandip; Hillers, Lauren E; Blake, Victoria M; Nishi, Yuichi; McFarlane, Matthew R; Chiang, Ason Cy; Kassis, Judith A; Allen, Benjamin L; McMahon, Andrew P; Barolo, Scott

    2016-01-01

    The Hedgehog signaling pathway is part of the ancient developmental-evolutionary animal toolkit. Frequently co-opted to pattern new structures, the pathway is conserved among eumetazoans yet flexible and pleiotropic in its effects. The Hedgehog receptor, Patched, is transcriptionally activated by Hedgehog, providing essential negative feedback in all tissues. Our locus-wide dissections of the cis-regulatory landscapes of fly patched and mouse Ptch1 reveal abundant, diverse enhancers with stage- and tissue-specific expression patterns. The seemingly simple, constitutive Hedgehog response of patched/Ptch1 is driven by a complex regulatory architecture, with batteries of context-specific enhancers engaged in promoter-specific interactions to tune signaling individually in each tissue, without disturbing patterning elsewhere. This structure-one of the oldest cis-regulatory features discovered in animal genomes-explains how patched/Ptch1 can drive dramatic adaptations in animal morphology while maintaining its essential core function. It may also suggest a general model for the evolutionary flexibility of conserved regulators and pathways. PMID:27146892

  5. An ancient yet flexible cis-regulatory architecture allows localized Hedgehog tuning by patched/Ptch1

    PubMed Central

    Lorberbaum, David S; Ramos, Andrea I; Peterson, Kevin A; Carpenter, Brandon S; Parker, David S; De, Sandip; Hillers, Lauren E; Blake, Victoria M; Nishi, Yuichi; McFarlane, Matthew R; Chiang, Ason CY; Kassis, Judith A; Allen, Benjamin L; McMahon, Andrew P; Barolo, Scott

    2016-01-01

    The Hedgehog signaling pathway is part of the ancient developmental-evolutionary animal toolkit. Frequently co-opted to pattern new structures, the pathway is conserved among eumetazoans yet flexible and pleiotropic in its effects. The Hedgehog receptor, Patched, is transcriptionally activated by Hedgehog, providing essential negative feedback in all tissues. Our locus-wide dissections of the cis-regulatory landscapes of fly patched and mouse Ptch1 reveal abundant, diverse enhancers with stage- and tissue-specific expression patterns. The seemingly simple, constitutive Hedgehog response of patched/Ptch1 is driven by a complex regulatory architecture, with batteries of context-specific enhancers engaged in promoter-specific interactions to tune signaling individually in each tissue, without disturbing patterning elsewhere. This structure—one of the oldest cis-regulatory features discovered in animal genomes—explains how patched/Ptch1 can drive dramatic adaptations in animal morphology while maintaining its essential core function. It may also suggest a general model for the evolutionary flexibility of conserved regulators and pathways. DOI: http://dx.doi.org/10.7554/eLife.13550.001 PMID:27146892

  6. Constitutive non-canonical NFκB signaling in pancreatic cancer cells

    PubMed Central

    Wharry, Catherine E.; Haines, Kathleen M.; Carroll, Richard G.; May, Michael J.

    2010-01-01

    Constitutive classical NFκB activation has been implicated in the development of pancreatic cancer, and inhibition of classical NFκB signaling sensitizes pancreatic cancer cells to apoptosis. However, the role of the more recently described non-canonical NFκB pathway has not been specifically addressed in pancreatic cancer. The non-canonical pathway requires stabilization of NIK and IKKα-dependent phosphorylation and processing of NFκB2/p100 to p52. This leads to the activation of p52-RelB heterodimers that regulate genes encoding lymphoid-specific chemokines and cytokines. We performed qRT-PCR to detect gene expression in a panel of pancreatic ductal adenocarcinoma cell lines (BxPC-3, PCA-2, PANC-1, Capan-1, Hs-766T, AsPC-1, MiaPACA-2) and found only modest elevation of classical NFκB-dependent genes. In contrast, each of the tumor cell lines displayed dramatically elevated levels of subsets of the non-canonical NFκB target genes CCL19, CCL21, CXCL12, CXCL13 and BAFF. Consistent with activation of the non-canonical pathway, p52 and RelB co-localized in adenocarcinoma cells in sections of pancreatic tumor tissue, and each of the tumor cell lines displayed elevated p52 levels. Furthermore, p52 and RelB co-immunoprecipitated from pancreatic cancer cells and immunoblotting revealed that NIK was stabilized and p100 was constitutively phosphorylated in a subset of the cell lines. Finally, stable overexpression of dominant negative IKKα significantly inhibited non-canonical target gene expression in BxPC-3 cells. These findings therefore demonstrate that the non-canonical NFκB pathway is constitutively active and functional in pancreatic cancer cells. PMID:19502791

  7. Neutrophils alter the inflammatory milieu by signal-dependent translation of constitutive messenger RNAs

    NASA Astrophysics Data System (ADS)

    Lindemann, Stephan W.; Yost, Christian C.; Denis, Melvin M.; McIntyre, Thomas M.; Weyrich, Andrew S.; Zimmerman, Guy A.

    2004-05-01

    The mechanisms by which neutrophils, key effector cells of the innate immune system, express new gene products in inflammation are largely uncharacterized. We found that they rapidly translate constitutive mRNAs when activated, a previously unrecognized response. One of the proteins synthesized without a requirement for transcription is the soluble IL-6 receptor , which translocates to endothelial cells and induces a temporal switch to mononuclear leukocyte recruitment. Its synthesis is regulated by a specialized translational control pathway that is inhibited by rapamycin, a bacterial macrolide with therapeutic efficacy in transplantation, inflammatory syndromes, and neoplasia. Signal-dependent translation in activated neutrophils may be a critical mechanism for alteration of the inflammatory milieu and a therapeutic target.

  8. Basal cell carcinomas: attack of the hedgehog.

    PubMed

    Epstein, Ervin H

    2008-10-01

    Basal cell carcinomas (BCCs) were essentially a molecular 'black box' until some 12 years ago, when identification of a genetic flaw in a rare subset of patients who have a great propensity to develop BCCs pointed to aberrant Hedgehog signalling as the pivotal defect leading to formation of these tumours. This discovery has facilitated a remarkable increase in our understanding of BCC carcinogenesis and has highlighted the carcinogenic role of this developmental pathway when aberrantly activated in adulthood. Importantly, a phase 1 first-in-human trial of a Hedgehog inhibitor has shown real progress in halting and even reversing the growth of these tumours.

  9. Cross-talk between Human Papillomavirus Oncoproteins and Hedgehog Signaling Synergistically Promotes Stemness in Cervical Cancer Cells

    PubMed Central

    Vishnoi, Kanchan; Mahata, Sutapa; Tyagi, Abhishek; Pandey, Arvind; Verma, Gaurav; Jadli, Mohit; Singh, Tejveer; Singh, Sukh Mahendra; Bharti, Alok C.

    2016-01-01

    Viral oncoproteins E6/E7 play key oncogenic role in human papillomavirus (HPV)-mediated cervical carcinogenesis in conjunction with aberrant activation of cellular signaling events. GLI-signaling has been implicated in metastasis and tumor recurrence of cervical cancer. However, the interaction of GLI-signaling with HPV oncogenes is unknown. We examined this relationship in established HPV-positive and HPV-negative cervical cancer cell lines using specific GLI inhibitor, cyclopamine and HPVE6/E7 siRNAs. Cervical cancer cell lines showed variable expression of GLI-signaling components. HPV16-positive SiHa cells, overexpressed GLI1, Smo and Patch. Inhibition by cyclopamine resulted in dose-dependent reduction of Smo and GLI1 and loss of cell viability with a higher magnitude in HPV-positive cells. Cyclopamine selectively downregulated HPVE6 expression and resulted in p53 accumulation, whereas HPVE7 and pRb level remained unaffected. siRNA-mediated silencing of HPV16E6 demonstrated reduced GLI1 transcripts in SiHa cells. Cervical cancer stem-like cells isolated by side population analysis, displayed retention of E6 and GLI1 expression. Fraction of SP cells was reduced in cyclopamine-treated cultures. When combined with E6-silencing cyclopamine resulted in loss of SP cell’s sphere-forming ability. Co-inhibition of GLI1 and E6 in cervical cancer cells showed additive anti-cancer effects. Overall, our data show existence of a cooperative interaction between GLI signaling and HPVE6. PMID:27678330

  10. Hedgehog and Fgf Signaling Pathways Regulate the Development of tphR-Expressing Serotonergic Raphe Neurons in Zebrafish Embryos

    PubMed Central

    Teraoka, H.; Russell, C.; Regan, J.; Chandrasekhar, A.; Concha, M. L.; Yokoyama, R.; Higashi, K.; Take-uchi, M.; Dong, W.; Hiraga, T.; Holder, N.; Wilson, S. W.

    2009-01-01

    Serotonin (5HT) plays major roles in the physiological regulation of many behavioral processes, including sleep, feeding, and mood, but the genetic mechanisms by which serotonergic neurons arise during development are poorly understood. In the present study, we have investigated the development of serotonergic neurons in the zebrafish. Neurons exhibiting 5HT-immunoreactivity (5HT-IR) are detected from 45 h postfertilization (hpf) in the ventral hindbrain raphe, the hypothalamus, pineal organ, and pretectal area. Tryptophan hydroxylases encode rate-limiting enzymes that function in the synthesis of 5HT. As part of this study, we cloned and analyzed a novel zebrafish tph gene named tphR. Unlike two other zebrafish tph genes (tphD1 and tphD2), tphR is expressed in serotonergic raphe neurons, similar to tph genes in mammalian species. tphR is also expressed in the pineal organ where it is likely to be involved in the pathway leading to synthesis of melatonin. To better understand the signaling pathways involved in the induction of the serotonergic phenotype, we analyzed tphR expression and 5HT-IR in embryos in which either Hh or Fgf signals are abrogated. Hindbrain 5HT neurons are severely reduced in mutants lacking activity of either Ace/Fgf8 or the transcription factor Noi/Pax2.1, which regulates expression of ace/fgf8, and probably other genes encoding signaling proteins. Similarly, serotonergic raphe neurons are absent in embryos lacking Hh activity confirming a conserved role for Hh signals in the induction of these cells. Conversely, over-activation of the Hh pathway increases the number of serotonergic neurons. As in mammals, our results are consistent with the transcription factors Nk2.2 and Gata3 acting downstream of Hh activity in the development of serotonergic raphe neurons. Our results show that the pathways involved in induction of hindbrain serotonergic neurons are likely to be conserved in all vertebrates and help establish the zebrafish as a model

  11. Constitutive Phosphorylation of Interferon Receptor A-Associated Signaling Proteins in Systemic Lupus Erythematosus

    PubMed Central

    Ramírez-Vélez, Gabriela; Medina, Francisco; Ramírez-Montaño, Luis; Zarazúa-Lozada, Abraham; Hernández, Ramiro; Llorente, Luis; Moreno, José

    2012-01-01

    Background Overexpression of type I interferon (IFN-I)-induced genes is a common feature of systemic lupus erythematosus (SLE) and its experimental models, but the participation of endogenous overproduction of IFN-I on it is not clear. To explore the possibility that abnormally increased IFN-I receptor (IFNAR) signaling could participate in IFN-I-induced gene overexpression of SLE, we examined the phosphorylation status of the IFNAR-associated signaling partners Jak1 and STAT2, and its relation with expression of its physiologic inhibitor SOCS1 and with plasma levels of IFNα and IFN-like activity. Methodology/Principal Findings Peripheral blood mononuclear cells (PBMC) from SLE patients with or without disease activity and healthy controls cultured in the presence or in the absence of IFNβ were examined by immunoprecipitation and/or western blotting for expression of the two IFNAR chains, Jak1, Tyk2, and STAT2 and their phosphorylated forms. In SLE but not in healthy control PBMC, Jak1 and STAT2 were constitutively phosphorylated, even in the absence of disease activity (basal pJak1: controls vs. active SLE p<0.0001 and controls vs. inactive SLE p = 0.0006; basal pSTAT2: controls vs. active and inactive SLE p<0.0001). Although SOCS1 protein was slightly but significantly decreased in SLE in the absence or in the presence of IFNβ (p = 0.0096 to p<0.0001), in SOCS1 mRNA levels were markedly decreased (p = 0.036 to p<0.0001). IFNβ induced higher levels of the IFN-I-dependent MxA protein mRNA in SLE than in healthy controls, whereas the opposite was observed for SOCS1. Although there was no relation to increased serum IFNα, active SLE plasma could induce expression of IFN-dependent genes by normal PBMC. Conclusions/Significance These findings suggest that in some SLE patients IFN-I dependent gene expression could be the result of a low IFNAR signaling threshold. PMID:22859983

  12. Hedgehog inhibitors from Withania somnifera.

    PubMed

    Yoneyama, Tatsuro; Arai, Midori A; Sadhu, Samir K; Ahmed, Firoj; Ishibashi, Masami

    2015-09-01

    The hedgehog (Hh) signaling pathway performs an important role in embryonic development and in cellular proliferation and differentiation. However, aberrant activation of the Hh signaling pathway is associated with tumorigenesis. Hh signal inhibition was evaluated using a cell-based assay system that targets GLI1-mediated transcription. Activity-guided isolation of the Withania somnifera MeOH extract led to the isolation of six compounds: withaferin A (1) and its derivatives (2-6). Compounds 1 and 2 showed strong inhibition of Hh/GLI1-mediated transcriptional activity with IC50 values of 0.5 and 0.6 μM, respectively. Compounds 1, 2, 3, and 6 were cytotoxic toward human pancreatic (PANC-1), prostate (DU145) and breast (MCF7) cancer cells. Furthermore, 1 also inhibited GLI1-DNA complex formation in EMSA.

  13. Rho GTPase signaling promotes constitutive expression and release of TGF-β2 by human trabecular meshwork cells.

    PubMed

    Pervan, Cynthia L; Lautz, Jonathan D; Blitzer, Andrea L; Langert, Kelly A; Stubbs, Evan B

    2016-05-01

    Elevated intraocular pressure (IOP) is causally implicated in the pathophysiology of primary open-angle glaucoma (POAG). The molecular mechanisms responsible for elevated IOP remain elusive, but may involve aberrant expression and signaling of transforming growth factor (TGF)-β2 within the trabecular meshwork (TM). Consistent with previously published studies, we show here that exogenous addition of TGF-β2 to cultured porcine anterior segments significantly attenuates outflow facility in a time-dependent manner. By comparison, perfusing segments with a TGFβRI/ALK-5 antagonist (SB-431542) unexpectedly elicited a significant and sustained increase in outflow facility, implicating a role for TM-localized constitutive expression and release of TGF-β2. Consistent with this thesis, cultured primary or transformed (GTM3) quiescent human TM cells were found to constitutively express and secrete measurable amounts of biologically-active TGF-β2. Disrupting monomeric GTPase post-translational prenylation and activation with lovastatin or GGTI-298 markedly reduced constitutive TGF-β2 expression and release. Specifically, inhibiting the Rho subfamily of GTPases with C3 exoenzyme similarly reduced constitutive expression and secretion of TGF-β2. These findings suggest that Rho GTPase signaling, in part, regulates constitutive expression and release of biologically-active TGF-β2 from human TM cells. Localized constitutive expression and release of TGF-β2 by TM cells may promote or exacerbate elevation of IOP in POAG.

  14. Hedgehog regulates cerebellar progenitor cell and medulloblastoma apoptosis.

    PubMed

    Noguchi, Kevin Kiyoshi; Cabrera, Omar Hoseá; Swiney, Brant S; Salinas-Contreras, Patricia; Smith, Julie Kathryn; Farber, Nuri B

    2015-11-01

    The external granule layer (EGL) is a proliferative region that produces over 90% of the neurons in the cerebellum but can also malignantly transform into a cerebellar tumor called the medulloblastoma (the most common malignant brain tumor in children). Current dogma considers Hedgehog stimulation a potent proliferative signal for EGL neural progenitor cells (NPCs) and medulloblastomas. However, the Hedgehog pathway also acts as a survival signal in the neural tube where it regulates dorsoventral patterning by controlling NPC apoptosis. Here we show that Hedgehog stimulation is also a potent survival signal in the EGL and medulloblastomas that produces a massive apoptotic response within hours of signal loss in mice. This toxicity can be produced by numerous Hedgehog antagonists (vismodegib, cyclopamine, and jervine) and is Bax/Bak dependent but p53 independent. Finally, since glucocorticoids can also induce EGL and medulloblastoma apoptosis, we show that Hedgehog's effects on apoptosis can occur independent of glucocorticoid stimulation. This effect may play a major role in cerebellar development by directing where EGL proliferation occurs thereby morphologically sculpting growth. It may also be a previously unknown major therapeutic effect of Hedgehog antagonists during medulloblastoma therapy. Results are discussed in terms of their implications for both cerebellar development and medulloblastoma treatment. PMID:26319366

  15. The hedgehog system in ovarian follicles of cattle selected for twin ovulations and births: evidence of a link between the IGF and hedgehog systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hedgehog signaling is involved in regulation of ovarian function in Drosophila but its role in regulating mammalian ovarian folliculogenesis is less clear. Therefore, gene expression of Indian hedgehog (IHH) and its type 1 receptor, patched 1 (PTCH1), were quantified in bovine granulosa (GC) or the...

  16. Constitutive and hyperresponsive signaling by mutant forms of Saccharomyces cerevisiae amino acid sensor Ssy1.

    PubMed

    Gaber, Richard F; Ottow, Kim; Andersen, Helge A; Kielland-Brandt, Morten C

    2003-10-01

    Sensing of extracellular amino acids results in transcriptional induction of amino acid permease genes in yeast. Ssy1, a membrane protein resembling amino acid permeases, is required for signaling but is apparently unable to transport amino acids and is thus believed to be a sensor. By using a novel genetic screen in which potassium uptake was made dependent on amino acid signaling, we obtained gain-of-function mutations in SSY1. Some alleles confer inducer-independent signaling; others increase the apparent affinity for inducers. The results reveal that amino acid transport is not required for signaling and support the notion that sensing by Ssy1 occurs via its direct interaction with extracellular amino acids. PMID:14555474

  17. Calcium-sensing receptors signal constitutive macropinocytosis and facilitate the uptake of NOD2 ligands in macrophages.

    PubMed

    Canton, Johnathan; Schlam, Daniel; Breuer, Christian; Gütschow, Michael; Glogauer, Michael; Grinstein, Sergio

    2016-01-01

    Macropinocytosis can be induced in several cell types by stimulation with growth factors. In selected cell types, notably macrophages and dendritic cells, macropinocytosis occurs constitutively, supporting the uptake of antigens for subsequent presentation. Despite their different mode of initiation and contrasting physiological roles, it is tacitly assumed that both types of macropinocytosis are mechanistically identical. We report that constitutive macropinocytosis is stringently calcium dependent, while stimulus-induced macropinocytosis is not. Extracellular calcium is sensed by G-protein-coupled calcium-sensing receptors (CaSR) that signal macropinocytosis through Gα-, phosphatidylinositol 3-kinase and phospholipase C. These pathways promote the recruitment of exchange factors that stimulate Rac and/or Cdc42, driving actin-dependent formation of ruffles and macropinosomes. In addition, the heterologous expression of CaSR in HEK293 cells confers on them the ability to perform constitutive macropinocytosis. Finally, we show that CaSR-induced constitutive macropinocytosis facilitates the sentinel function of macrophages, promoting the efficient delivery of ligands to cytosolic pattern-recognition receptors. PMID:27050483

  18. A novel platinum compound inhibits constitutive Stat3 signaling and induces cell cycle arrest and apoptosis of malignant cells.

    PubMed

    Turkson, James; Zhang, Shumin; Mora, Linda B; Burns, Audrey; Sebti, Said; Jove, Richard

    2005-09-23

    Previous studies have established constitutive activation of Stat3 protein as one of the molecular changes required for tumorigenesis. To develop novel therapeutics for tumors harboring constitutively active Stat3, compounds from the NCI 2000 diversity set were evaluated for inhibition of Stat3 DNA-binding activity in vitro. Of these, a novel platinum (IV) compound, IS3 295, interacted with Stat3 and inhibited its binding to specific DNA-response elements. Further analysis suggested noncompetitive-type kinetics for the inhibition of Stat3 binding to DNA. In human and mouse tumor cell lines with constitutively active Stat3, IS3 295 selectively attenuated Stat3 signaling, thereby inducing cell growth arrest at G0/G1 phase and apoptosis. Moreover, in transformed cells, IS3 295 repressed expression of cyclin D1 and bcl-xL, two of the known Stat3-regulated genes that are overexpressed in malignant cells, suggesting that IS3 295 mediates anti-tumor cell activity in part by blocking Stat3-mediated sub-version of cell growth and apoptotic signals. Together, our findings provide evidence for the inhibition of Stat3 activity and biological functions by IS3 295 through interaction with Stat3 protein. This study represents a significant advance in small molecule-based approaches to target Stat3 and suggests potential new applications for platinum (IV) complexes as modulators of the Stat3 pathway for cancer therapy.

  19. Constitutively active Notch1 induces growth arrest of HPV-positive cervical cancer cells via separate signaling pathways

    SciTech Connect

    Talora, Claudio; Cialfi, Samantha; Segatto, Oreste; Morrone, Stefania; Kim Choi, John; Frati, Luigi; Paolo Dotto, Gian; Gulino, Alberto; Screpanti, Isabella . E-mail: isabella.screpanti@uniroma1.it

    2005-05-01

    Notch signaling plays a key role in cell-fate determination and differentiation in different organisms and cell types. Several reports suggest that Notch signaling may be involved in neoplastic transformation. However, in primary keratinocytes, Notch1 can function as a tumor suppressor. Similarly, in HPV-positive cervical cancer cells, constitutively active Notch1 signaling was found to cause growth suppression. Activated Notch1 in these cells represses viral E6/E7 expression through AP-1 down-modulation, resulting in increased p53 expression and a block of pRb hyperphosphorylation. Here we show that in cervical cancer cell lines in which Notch1 ability to repress AP-1 activity is impaired, Notch1-enforced expression elicits an alternative pathway leading to growth arrest. Indeed, activated Notch1 signaling suppresses activity of the helix-loop-helix transcription factor E47, via ERK1/2 activation, resulting in inhibition of cell cycle progression. Moreover, we found that RBP-J{kappa}-dependent Notch signaling is specifically repressed in cervical cancer cells and this repression could provide one such mechanism that needs to be activated for cervical carcinogenesis. Finally, we show that inhibition of endogenous Notch1 signaling, although results in a proliferative advantage, sensitizes cervical cancer cell lines to drug-induced apoptosis. Together, our results provide novel molecular insights into Notch1-dependent growth inhibitory effects, counteracting the transforming potential of HPV.

  20. Membrane Topology of Hedgehog Acyltransferase*

    PubMed Central

    Matevossian, Armine; Resh, Marilyn D.

    2015-01-01

    Hedgehog acyltransferase (Hhat) is a multipass transmembrane enzyme that mediates the covalent attachment of the 16-carbon fatty acid palmitate to the N-terminal cysteine of Sonic Hedgehog (Shh). Palmitoylation of Shh by Hhat is critical for short and long range signaling. Knowledge of the topological organization of Hhat transmembrane helices would enhance our understanding of Hhat-mediated Shh palmitoylation. Bioinformatics analysis of transmembrane domains within human Hhat using 10 different algorithms resulted in highly consistent predictions in the C-terminal, but not in the N-terminal, region of Hhat. To empirically determine the topology of Hhat, we designed and exploited Hhat constructs containing either terminal or 12 different internal epitope tags. We used selective permeabilization coupled with immunofluorescence as well as a protease protection assay to demonstrate that Hhat contains 10 transmembrane domains and 2 re-entrant loops. The invariant His and highly conserved Asp residues within the membrane-bound O-acyltransferase (MBOAT) homology domain are segregated on opposite sides of the endoplasmic reticulum membrane. The localization of His-379 on the lumenal membrane surface is consistent with a role for this invariant residue in catalysis. Analysis of the activity and stability of the Hhat constructs revealed that the C-terminal MBOAT domain is especially sensitive to manipulation. Moreover, there was remarkable similarity in the overall topological organization of Hhat and ghrelin O-acyltransferase, another MBOAT family member. Knowledge of the topological organization of Hhat could serve as an important tool for further design of selective Hhat inhibitors. PMID:25488661

  1. Interleukin-6: A Constitutive Modulator of Glycoprotein 130, Neuroinflammatory and Cell Survival Signaling in Retina

    PubMed Central

    Echevarria, Franklin D.; Rickman, Abigayle E.; Sappington, Rebecca M.

    2016-01-01

    Objective The interleukin-6 (IL-6) family of cytokines and their signal transducer glycoprotein (gp130) are implicated in inflammatory and cell survival functions in glaucoma. There are several avenues for interdependent modulation of IL-6 family members and gp130 signaling. Here we investigated whether IL-6 modulates gp130 and related neuroinflammatory, cell survival and regulatory signaling in both healthy and glaucomatous retina. Methods In naïve and glaucomatous (Microbead Occlusion Model), wildtype (WT) and IL-6 knockout (IL-6−/−) mice, we examined gp130 protein expression and localization, using western blot and immunohistochemistry. Gene targets related to IL-6 and gp130 signaling and pertinent to neuroinflammation (TNFα, IL-1β), cell health (Bax, Bcl-xl) and STAT3 regulation (Socs3) were quantified using qRTPCR. Results In the naïve retina, IL-6−/− retina contained significantly less gp130 compared to WT retina. This IL-6-related decrease in gp130 was accompanied by a reduction in mRNA expression of TNFα, Socs3 and Bax. After 4 weeks of microbead-induced ocular hypertension, both microbead- and saline-injected (control) eyes of IL-6−/− mice exhibited higher expression of TNFα, compared to WT mice. IL-1β expression was also reduced specifically in IL-6−/− retina with microbead-induced glaucoma. While saline and microbead injection increased Bcl-xl and Socs3 mRNA in both WT and IL-6−/− mice, IL-6−/− deficiency led to smaller increases for both Bcl-xl and Socs3. Conclusions Our findings support a role for IL-6 in setting baseline parameters for neuroinflammatory, cell health and gp130 regulatory signaling that can impact the nature and magnitude of retinal responses to glaucoma-related stressors.

  2. Mathematical model of cAMP-dependent signaling pathway in constitutive and UV-induced melanogenesis

    NASA Astrophysics Data System (ADS)

    Stolnitz, Mikhail M.; Peshkova, Anna Y.

    2002-07-01

    Cascade of reactions of cAMP-dependent signaling pathway in melanocytes is investigated by mathematical modeling. Model takes into account (alpha) -melanocyte stimulating hormone binding to melanocortin-1 receptor, adenylate cyclase activation by G-protein, increase of the intracellular cAMP concentration, PKA activation by cAMP, CREB phosphorylation by PKA, microphthalmia gene expression, microphthalmia binding to tyrosinase gene promoter, increase of tyrosinase synthesis. Positive and negative feedback loops of this system are analyzed.

  3. Constitutive Mad1 targeting to kinetochores uncouples checkpoint signalling from chromosome biorientation.

    PubMed

    Maldonado, Maria; Kapoor, Tarun M

    2011-04-01

    Accurate chromosome segregation depends on biorientation, whereby sister chromatids attach to microtubules from opposite spindle poles. The spindle-assembly checkpoint is a surveillance mechanism in eukaryotes that inhibits anaphase until all chromosomes have bioriented. In present models, the recruitment of the spindle-assembly checkpoint protein Mad2, through Mad1, to non-bioriented kinetochores is needed to stop cell-cycle progression. However, it is unknown whether Mad1-Mad2 targeting to kinetochores is sufficient to block anaphase. Furthermore, it is unclear whether regulators of biorientation (for example, Aurora kinases) have checkpoint functions downstream of Mad1-Mad2 recruitment or whether they act upstream to quench the primary error signal. Here, we engineered a Mad1 construct that localizes to bioriented kinetochores. We show that the kinetochore localization of Mad1 is sufficient for a metaphase arrest that depends on Mad1-Mad2 binding. By uncoupling the checkpoint from its primary error signal, we show that Aurora, Mps1 and BubR1 kinases, but not Polo-like kinase, are needed to maintain checkpoint arrest when Mad1 is present on kinetochores. Together, our data suggest a model in which the biorientation errors, which recruit Mad1-Mad2 to kinetochores, may be signalled not only through Mad2 template dynamics, but also through the activity of widely conserved kinases, to ensure the fidelity of cell division.

  4. Folate deprivation enhances invasiveness of human colon cancer cells mediated by activation of sonic hedgehog signaling through promoter hypomethylation and cross action with transcription nuclear factor-kappa B pathway.

    PubMed

    Wang, Tz-Ping; Hsu, Shu-Han; Feng, Hsin-Chun; Huang, Rwei-Fen S

    2012-06-01

    Low folate status is well recognized as one of the metabolic stressors for colorectal cancer carcinogenesis, but its role in colon cancer invasion remains unknown. Activation of the Sonic hedgehog (Shh) signal in interaction with the transcription nuclear factor-kappa B (NF-κB) pathway is crucial for cancer aggressiveness. The aims of this study were to investigate whether and how folate deprivation promotes invasion by colon cancer cells in relation to Shh signaling and NF-κB pathway activation. Cultivation of epithelial colon carcinoma-derived cells (HCT116) in folate-deficient (FD) medium enhanced cellular migration and invasion, in correlation with epithelial-mesenchymal transition (EMT) associated with Snail expression and E-cadherin suppression, increased production of β1 integrin and increased proteolysis by matrix metalloproteinase 2. Blockade of Shh signaling by cyclopamine (CYC) or of NF-κB activation by BAY abolished FD-enhanced EMT and invasion by HCT116 cells. FD cells had 50-80% less intracellular folate, associated with aberrant hypomethylation of the Shh promoter, than control cells, and increased binding of nuclear NF-κB subunit p65 to the Shh promoter region, which coincided with increased Shh expression and protein production of Shh ligand; in addition, the FD-induced Shh signaling targeted Gli1 transcription activator as well as Ptch receptor. The FD-induced Shh induction and activated signaling were blocked by NF-κB inhibitor BAY. Blockade of Shh signaling abrogated FD-promoted NF-κB activation measured by IκBα degradation and by target gene TNFα expression. Taken together, these findings demonstrate that folate deprivation enhanced invasiveness of colon cancer cells mediated by activation of Shh signaling through promoter hypomethylation and cross actions with the NF-κB pathway.

  5. Novel Hedgehog pathway targets against basal cell carcinoma

    SciTech Connect

    Tang, Jean Y. So, P.-L.; Epstein, Ervin H.

    2007-11-01

    The Hedgehog signaling pathway plays a key role in directing growth and patterning during embryonic development and is required in vertebrates for the normal development of many structures, including the neural tube, axial skeleton, skin, and hair. Aberrant activation of the Hedgehog (Hh) pathway in adult tissue is associated with the development of basal cell carcinoma (BCC), medulloblastoma, and a subset of pancreatic, gastrointestinal, and other cancers. This review will provide an overview of what is known about the mechanisms by which activation of Hedgehog signaling leads to the development of BCCs and will review two recent papers suggesting that agents that modulate sterol levels might influence the Hh pathway. Thus, sterols may be a new therapeutic target for the treatment of BCCs, and readily available agents such as statins (HMG-CoA reductase inhibitors) or vitamin D might be helpful in reducing BCC incidence.

  6. Convergence of CONSTITUTIVE PHOTOMORPHOGENESIS 1 and PHYTOCHROME INTERACTING FACTOR signalling during shade avoidance.

    PubMed

    Pacín, Manuel; Semmoloni, Mariana; Legris, Martina; Finlayson, Scott A; Casal, Jorge J

    2016-08-01

    Shade-avoidance responses require CONSTITUTIVE PHOTOMORPHOGENESIS 1 (COP1) but the mechanisms of action of COP1 under shade have not been elucidated. Using simulated shade and control conditions, we analysed: the transcriptome and the auxin levels of cop1 and phytochrome interacting factor 1 (pif1) pif3 pif4 pif5 (pifq) mutants; the dynamics of ELONGATED HYPOCOTYL 5 (HY5) and LONG HYPOCOTYL IN FAR-RED (HFR1) proteins; and the epistatic relationships between cop1 and pif3, pif4, pif5, hy5 and hfr1 mutations in Arabidopsis thaliana. Despite severely impaired shade-avoidance responses, only a few genes that responded to shade in the wild-type failed to do so in cop1. Shade enhanced the convergence between cop1 and pifq transcriptomes, mainly on shade-avoidance marker genes. Shade failed to increase auxin levels in cop1. Residual shade avoidance in cop1 was not further reduced by the pif3, pif4 or pif5 mutations, suggesting convergent pathways. HFR1 stability decreased under shade in a COP1-dependent manner but shade increased HY5 stability. The cop1 mutant retains responses to shade and is more specifically impaired in shade avoidance. COP1 promotes the degradation of HFR1 under shade, thus increasing the ability of PIFs to control gene expression, increase auxin levels and promote stem growth.

  7. CT-2576, an inhibitor of phospholipid signaling, suppresses constitutive and induced expression of human immunodeficiency virus.

    PubMed Central

    Leung, D W; Peterson, P K; Weeks, R; Gekker, G; Chao, C C; Kaplan, A H; Balantac, N; Tompkins, C; Underiner, G E; Bursten, S

    1995-01-01

    Viruses such as human immunodeficiency virus (HIV) require cellular activation for expression. Cellular activation in lymphoid cells is associated with augmented accumulation of certain phosphatidic acid (PA) species derived from the hydrolysis of glycan phosphatidylinositol (GPI). This suggests that activation of a phospholipid pathway may play a role in initiation of viral replication. To test this hypothesis, we examined the effect of tat gene expression on the production of cellular PA species, as the Tat protein is essential for HIV expression and has been implicated in activating the expression of multiple host cellular genes. Expression of tat increased the expression of PA. We then tested whether synthetic inhibitors of PA metabolism would inhibit activation of the HIV long terminal repeat by Tat and tumor necrosis factor alpha (TNF-alpha). CT-2576 suppressed both PA generation induced by Tat and HIV long terminal repeat-directed gene expression in response to Tat or TNF-alpha at a posttranscriptional step. CT-2576 also inhibited constitutive as well as TNF-alpha- and interleukin 6-induced expression of HIV p24 antigen in chronically infected U1 cells and in peripheral blood lymphocytes acutely infected with a clinical isolate of HIV. Pharmacological inhibition of synthesis of selected PA species may therefore provide a therapeutic approach to suppression of HIV replication. Images Fig. 1 Fig. 3 Fig. 5 PMID:7761405

  8. Convergence of CONSTITUTIVE PHOTOMORPHOGENESIS 1 and PHYTOCHROME INTERACTING FACTOR signalling during shade avoidance.

    PubMed

    Pacín, Manuel; Semmoloni, Mariana; Legris, Martina; Finlayson, Scott A; Casal, Jorge J

    2016-08-01

    Shade-avoidance responses require CONSTITUTIVE PHOTOMORPHOGENESIS 1 (COP1) but the mechanisms of action of COP1 under shade have not been elucidated. Using simulated shade and control conditions, we analysed: the transcriptome and the auxin levels of cop1 and phytochrome interacting factor 1 (pif1) pif3 pif4 pif5 (pifq) mutants; the dynamics of ELONGATED HYPOCOTYL 5 (HY5) and LONG HYPOCOTYL IN FAR-RED (HFR1) proteins; and the epistatic relationships between cop1 and pif3, pif4, pif5, hy5 and hfr1 mutations in Arabidopsis thaliana. Despite severely impaired shade-avoidance responses, only a few genes that responded to shade in the wild-type failed to do so in cop1. Shade enhanced the convergence between cop1 and pifq transcriptomes, mainly on shade-avoidance marker genes. Shade failed to increase auxin levels in cop1. Residual shade avoidance in cop1 was not further reduced by the pif3, pif4 or pif5 mutations, suggesting convergent pathways. HFR1 stability decreased under shade in a COP1-dependent manner but shade increased HY5 stability. The cop1 mutant retains responses to shade and is more specifically impaired in shade avoidance. COP1 promotes the degradation of HFR1 under shade, thus increasing the ability of PIFs to control gene expression, increase auxin levels and promote stem growth. PMID:27105120

  9. Inhibition of constitutive signal transducer and activator of transcription 3 activation by novel platinum complexes with potent antitumor activity.

    PubMed

    Turkson, James; Zhang, Shumin; Palmer, Jay; Kay, Heidi; Stanko, Joseph; Mora, Linda B; Sebti, Said; Yu, Hua; Jove, Richard

    2004-12-01

    DNA-alkylating agents that are platinum complexes induce apoptotic responses and have wide application in cancer therapy. The potential for platinum compounds to modulate signal transduction events that contribute to their therapeutic outcome has not been extensively examined. Among the signal transducer and activator of transcription (STAT) proteins, Stat3 activity is frequently up-regulated in many human tumors. Various lines of evidence have established a causal role for aberrant Stat3 activity in malignant transformation and provided validation for its targeting in the development of small-molecule inhibitors as novel cancer therapeutics. We report here that platinum-containing compounds disrupt Stat3 signaling and suppress its biological functions. The novel platinum (IV) compounds, CPA-1, CPA-7, and platinum (IV) tetrachloride block Stat3 activity in vitro at low micromolar concentrations. In malignant cells that harbor constitutively activated Stat3, CPA-1, CPA-7, and platinum (IV) tetrachloride inhibit cell growth and induce apoptosis in a manner that reflects the attenuation of persistent Stat3 activity. By contrast, cells that do not contain persistent Stat3 activity are marginally affected or are not affected by these compounds. Moreover, CPA-7 induces the regression of mouse CT26 colon tumor, which correlates with the abrogation of persistent Stat3 activity in tumors. Thus, the modulation of oncogenic signal transduction pathways, such as Stat3, may be one of the key molecular mechanisms for the antitumor effects of platinum (IV)-containing complexes.

  10. Sonic hedgehog functions upstream of disrupted-in-schizophrenia 1 (disc1): implications for mental illness

    PubMed Central

    Boyd, Penelope J.; Cunliffe, Vincent T.; Roy, Sudipto; Wood, Jonathan D.

    2015-01-01

    ABSTRACT DISRUPTED-IN-SCHIZOPHRENIA (DISC1) has been one of the most intensively studied genetic risk factors for mental illness since it was discovered through positional mapping of a translocation breakpoint in a large Scottish family where a balanced chromosomal translocation was found to segregate with schizophrenia and affective disorders. While the evidence for it being central to disease pathogenesis in the original Scottish family is compelling, recent genome-wide association studies have not found evidence for common variants at the DISC1 locus being associated with schizophrenia in the wider population. It may therefore be the case that DISC1 provides an indication of biological pathways that are central to mental health issues and functional studies have shown that it functions in multiple signalling pathways. However, there is little information regarding factors that function upstream of DISC1 to regulate its expression and function. We herein demonstrate that Sonic hedgehog (Shh) signalling promotes expression of disc1 in the zebrafish brain. Expression of disc1 is lost in smoothened mutants that have a complete loss of Shh signal transduction, and elevated in patched mutants which have constitutive activation of Shh signalling. We previously demonstrated that disc1 knockdown has a dramatic effect on the specification of oligodendrocyte precursor cells (OPC) in the hindbrain and Shh signalling is known to be essential for the specification of these cells. We show that disc1 is prominently expressed in olig2-positive midline progenitor cells that are absent in smo mutants, while cyclopamine treatment blocks disc1 expression in these cells and mimics the effect of disc1 knock down on OPC specification. Various features of a number of psychiatric conditions could potentially arise through aberrant Hedgehog signalling. We therefore suggest that altered Shh signalling may be an important neurodevelopmental factor in the pathobiology of mental illness. PMID

  11. The Hedgehog gene family of the cnidarian, Nematostella vectensis, and implications for understanding metazoan Hedgehog pathway evolution

    PubMed Central

    Matus, David Q.; Magie, Craig; Pang, Kevin; Martindale, Mark Q; Thomsen, Gerald H.

    2008-01-01

    Hedgehog signaling is an important component of cell-cell communication during bilaterian development, and abnormal Hedgehog signaling contributes to disease and birth defects. Hedgehog genes are composed of a ligand (“hedge”) domain and an autocatalytic intein (“hog”) domain. Hedgehog (hh) ligands bind to a conserved set of receptors and activate downstream signal transduction pathways terminating with Gli/Ci transcription factors. We have identified five intein-containing genes in the anthozoan cnidarian Nematostella vectensis, two of which (NvHh1 and NvHh2) contain definitive hedgehog ligand domains, suggesting that to date, cnidarians are the earliest branching metazoan phylum to possess definitive Hh orthologs. Expression analysis of NvHh1 and NvHh2, the receptor NvPatched and a downstream transcription factor NvGli (a Gli3/Ci ortholog) indicate that these genes may have conserved roles in planar and trans-epithelial signaling during gut and germline development, while the three remaining intein-containing genes (NvHint1,2,3) are expressed in a cell-type specific manner in putative neural precursors. Metazoan intein-containing genes that lack a ligand domain have previously only been identified within nematodes. However, phylogenetic analyses suggest that these nematode inteins may be derived from an ancestral nematode true hedgehog gene, and that the non-bilaterian intein-containing genes identified here may represent an ancestral state prior to the domain swapping events that resulted in the formation of true hedgehog genes in the cnidarian-bilaterian ancestor. Genomic surveys of N. vectensis suggest that most of the components of both protostome and deuterostome Hh signaling pathways are present in anthozoans and that some appear to have been lost in ecdysozoan lineages. Cnidarians possess many bilaterian cell-cell signaling pathways (Wnt, TGFß, FGF and Hh) that appear to act in concert to pattern tissues along the oral-aboral axis of the polyp

  12. Inhibition of the integrin signal constitutes a mouse iPS cell niche.

    PubMed

    Higuchi, Sayaka; Yoshina, Sawako; Mitani, Shohei

    2016-09-01

    Stem cells are regulated by their surrounding microenvironments, called niche, such as cell-cell interaction and extracellular matrix. Classically, feeder cells as a niche have been used in the culture of iPS cells from both the mouse and the human. However, the regulation mechanism of stem cells by feeder cells as a niche still have been partially unclear. In this study, we used three murine iPS cell lines, iPS-MEF-Ng-20D-17, iPS-MEF-Ng-178B-5 and iPS-MEF-Fb/Ng-440A-3, which were generated by different reprogramming methods. In general, these cell lines commonly need the feeder cells as a niche to culture. Recently, the effect of substrate stiffness is known in stem cell study. First, we focused on the mechanical properties of feeder cells, and then we speculated that feeder-less culture might be made possible by using molecules in place of the mechanical properties of the niche. Finally, we found that the combination of disintegrin (echistatin) and 2i (GSK3 inhibitor and MEK inhibitor) is a sufficient condition for three murine iPS culture. This novel method of mimicking the murine iPS cell niche may be useful to understand signaling pathways to maintain the pluripotency of stem cells. PMID:27633818

  13. Itraconazole Side Chain Analogues: Structure–Activity Relationship Studies for Inhibition of Endothelial Cell Proliferation, Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) Glycosylation, and Hedgehog Signaling

    PubMed Central

    Shi, Wei; Nacev, Benjamin A.; Aftab, Blake T.; Head, Sarah; Rudin, Charles M.; Liu, Jun O.

    2012-01-01

    Itraconazole is an antifungal drug that was recently found to possess potent antiangiogenic activity and anti-hedgehog (Hh) pathway activity. To search for analogues of itraconazole with greater potency and to understand the structure–activity relationship in both antiangiogenic and Hh targeting activity, 25 itraconazole side chain analogues were synthesized and assayed for inhibition of endothelial cell proliferation and Gli1 transcription in a medulloblastoma (MB) culture. Through this analysis, we have identified analogues with increased potency for inhibiting endothelial cell proliferation and the Hh pathway, as well as VEGFR2 glycosylation that was recently found to be inhibited by itraconazole. An SAR analysis of these activities revealed that potent activity of the analogues against VEGFR2 glycosylation was generally driven by side chains of at least four carbons in composition with branching at the α or β position. SAR trends for targeting the Hh pathway were divergent from those related to HUVEC proliferation or VEGFR2 glycosylation. These results also suggest that modification of the sec-butyl side chain can lead to enhancement of the biological activity of itraconazole. PMID:21936514

  14. Testing chemotherapeutic agents in the feather follicle identifies a selective blockade of cell proliferation and a key role for sonic hedgehog signaling in chemotherapy-induced tissue damage.

    PubMed

    Xie, Guojiang; Wang, Hangwei; Yan, Zhipeng; Cai, Linyan; Zhou, Guixuan; He, Wanzhong; Paus, Ralf; Yue, Zhicao

    2015-03-01

    Chemotherapeutic agents induce complex tissue responses in vivo and damage normal organ functions. Here we use the feather follicle to investigate details of this damage response. We show that cyclophosphamide treatment, which causes chemotherapy-induced alopecia in mice and man, induces distinct defects in feather formation: feather branching is transiently and reversibly disrupted, thus leaving a morphological record of the impact of chemotherapeutic agents, whereas the rachis (feather axis) remains unperturbed. Similar defects are observed in feathers treated with 5-fluorouracil or taxol but not with doxorubicin or arabinofuranosyl cytidine (Ara-C). Selective blockade of cell proliferation was seen in the feather branching area, along with a downregulation of sonic hedgehog (Shh) transcription, but not in the equally proliferative rachis. Local delivery of the Shh inhibitor, cyclopamine, or Shh silencing both recapitulated this effect. In mouse hair follicles, those chemotherapeutic agents that disrupted feather formation also downregulated Shh gene expression and induced hair loss, whereas doxorubicin or Ara-C did not. Our results reveal a mechanism through which chemotherapeutic agents damage rapidly proliferating epithelial tissue, namely via the cell population-specific, Shh-dependent inhibition of proliferation. This mechanism may be targeted by future strategies to manage chemotherapy-induced tissue damage.

  15. Self-renewal of leukemia stem cells in Friend virus-induced erythroleukemia requires proviral insertional activation of Spi1 and hedgehog signaling but not mutation of p53.

    PubMed

    Hegde, Shailaja; Hankey, Pamela; Paulson, Robert F

    2012-02-01

    Friend virus induces erythroleukemia through a characteristic two-stage progression. The prevailing model proposes that during the initial, polyclonal stage of disease most of the infected cells terminally differentiate, resulting in acute erythrocytosis. In the late stage of disease, a clonal leukemia develops through the acquisition of new mutations--proviral insertional activation of Spi1/Pu.1 and mutation of p53. Previous work from our laboratory demonstrated that Friend virus activates the bone morphogenic protein 4 (BMP4)-dependent stress erythropoiesis pathway, which leads to the rapid expansion of stress erythroid progenitors, which are the targets for Friend virus in the spleen. We recently showed that stress erythroid progenitors have intrinsic self-renewal ability and therefore could function as leukemia stem cells (LSCs) when infected with Friend virus. Here, we show that the two stages of Friend virus-induced disease are caused by infection of distinct stress progenitor populations in the spleen. The development of leukemia relies on the ability of the virus to hijack the intrinsic self-renewal capability of stress erythroid progenitors leading to the generation of LSCs. Two signals are required for the self-renewal of Friend virus LSCs proviral insertional activation of Spi1/Pu.1 and Hedgehog-dependent signaling. Surprisingly, mutation of p53 is not observed in LSCs. These data establish a new model for Friend virus-induced erythroleukemia and demonstrate the utility of Friend virus as a model system to study LSC self-renewal.

  16. An Ancestral Role for CONSTITUTIVE TRIPLE RESPONSE1 Proteins in Both Ethylene and Abscisic Acid Signaling1[OPEN

    PubMed Central

    Yasumura, Yuki; Pierik, Ronald; Kelly, Steven; Sakuta, Masaaki; Voesenek, Laurentius A.C.J.; Harberd, Nicholas P.

    2015-01-01

    Land plants have evolved adaptive regulatory mechanisms enabling the survival of environmental stresses associated with terrestrial life. Here, we focus on the evolution of the regulatory CONSTITUTIVE TRIPLE RESPONSE1 (CTR1) component of the ethylene signaling pathway that modulates stress-related changes in plant growth and development. First, we compare CTR1-like proteins from a bryophyte, Physcomitrella patens (representative of early divergent land plants), with those of more recently diverged lycophyte and angiosperm species (including Arabidopsis [Arabidopsis thaliana]) and identify a monophyletic CTR1 family. The fully sequenced P. patens genome encodes only a single member of this family (PpCTR1L). Next, we compare the functions of PpCTR1L with that of related angiosperm proteins. We show that, like angiosperm CTR1 proteins (e.g. AtCTR1 of Arabidopsis), PpCTR1L modulates downstream ethylene signaling via direct interaction with ethylene receptors. These functions, therefore, likely predate the divergence of the bryophytes from the land-plant lineage. However, we also show that PpCTR1L unexpectedly has dual functions and additionally modulates abscisic acid (ABA) signaling. In contrast, while AtCTR1 lacks detectable ABA signaling functions, Arabidopsis has during evolution acquired another homolog that is functionally distinct from AtCTR1. In conclusion, the roles of CTR1-related proteins appear to have functionally diversified during land-plant evolution, and angiosperm CTR1-related proteins appear to have lost an ancestral ABA signaling function. Our study provides new insights into how molecular events such as gene duplication and functional differentiation may have contributed to the adaptive evolution of regulatory mechanisms in plants. PMID:26243614

  17. Dissecting the Role of Hedgehog Pathway in Murine Gonadal Development

    ERIC Educational Resources Information Center

    Barsoum, Ivraym Boshra

    2009-01-01

    Hedgehog (Hh) signaling pathway is one of the universal pathways involved in animal development. This dissertation focuses on Hh role in the mammalian gonad development, which is a central part of mammalian sexual development and identity. The central dogma of mammalian sex development is that genetic sex determines the gonadal sex, which in turn…

  18. Inhibition of APP gamma-secretase restores Sonic Hedgehog signaling and neurogenesis in the Ts65Dn mouse model of Down syndrome.

    PubMed

    Giacomini, Andrea; Stagni, Fiorenza; Trazzi, Stefania; Guidi, Sandra; Emili, Marco; Brigham, Elizabeth; Ciani, Elisabetta; Bartesaghi, Renata

    2015-10-01

    Neurogenesis impairment starting from early developmental stages is a key determinant of intellectual disability in Down syndrome (DS). Previous evidence provided a causal relationship between neurogenesis impairment and malfunctioning of the mitogenic Sonic Hedgehog (Shh) pathway. In particular, excessive levels of AICD (amyloid precursor protein intracellular domain), a cleavage product of the trisomic gene APP (amyloid precursor protein) up-regulate transcription of Ptch1 (Patched1), the Shh receptor that keeps the pathway repressed. Since AICD results from APP cleavage by γ-secretase, the goal of the current study was to establish whether treatment with a γ-secretase inhibitor normalizes AICD levels and restores neurogenesis in trisomic neural precursor cells. We found that treatment with a selective γ-secretase inhibitor (ELND006; ELN) restores proliferation in neurospheres derived from the subventricular zone (SVZ) of the Ts65Dn mouse model of DS. This effect was accompanied by reduction of AICD and Ptch1 levels and was prevented by inhibition of the Shh pathway with cyclopamine. Treatment of Ts65Dn mice with ELN in the postnatal period P3-P15 restored neurogenesis in the SVZ and hippocampus, hippocampal granule cell number and synapse development, indicating a positive impact of treatment on brain development. In addition, in the hippocampus of treated Ts65Dn mice there was a reduction in the expression levels of various genes that are transcriptionally regulated by AICD, including APP, its origin substrate. Inhibitors of γ-secretase are currently envisaged as tools for the cure of Alzheimer's disease because they lower βamyloid levels. Current results provide novel evidence that γ-secretase inhibitors may represent a strategy for the rescue of neurogenesis defects in DS. PMID:26254735

  19. Inhibition of APP gamma-secretase restores Sonic Hedgehog signaling and neurogenesis in the Ts65Dn mouse model of Down syndrome.

    PubMed

    Giacomini, Andrea; Stagni, Fiorenza; Trazzi, Stefania; Guidi, Sandra; Emili, Marco; Brigham, Elizabeth; Ciani, Elisabetta; Bartesaghi, Renata

    2015-10-01

    Neurogenesis impairment starting from early developmental stages is a key determinant of intellectual disability in Down syndrome (DS). Previous evidence provided a causal relationship between neurogenesis impairment and malfunctioning of the mitogenic Sonic Hedgehog (Shh) pathway. In particular, excessive levels of AICD (amyloid precursor protein intracellular domain), a cleavage product of the trisomic gene APP (amyloid precursor protein) up-regulate transcription of Ptch1 (Patched1), the Shh receptor that keeps the pathway repressed. Since AICD results from APP cleavage by γ-secretase, the goal of the current study was to establish whether treatment with a γ-secretase inhibitor normalizes AICD levels and restores neurogenesis in trisomic neural precursor cells. We found that treatment with a selective γ-secretase inhibitor (ELND006; ELN) restores proliferation in neurospheres derived from the subventricular zone (SVZ) of the Ts65Dn mouse model of DS. This effect was accompanied by reduction of AICD and Ptch1 levels and was prevented by inhibition of the Shh pathway with cyclopamine. Treatment of Ts65Dn mice with ELN in the postnatal period P3-P15 restored neurogenesis in the SVZ and hippocampus, hippocampal granule cell number and synapse development, indicating a positive impact of treatment on brain development. In addition, in the hippocampus of treated Ts65Dn mice there was a reduction in the expression levels of various genes that are transcriptionally regulated by AICD, including APP, its origin substrate. Inhibitors of γ-secretase are currently envisaged as tools for the cure of Alzheimer's disease because they lower βamyloid levels. Current results provide novel evidence that γ-secretase inhibitors may represent a strategy for the rescue of neurogenesis defects in DS.

  20. Inhibition of APP gamma-secretase restores Sonic Hedgehog signaling and neurogenesis in the Ts65Dn mouse model of Down syndrome

    PubMed Central

    Giacomini, Andrea; Stagni, Fiorenza; Trazzi, Stefania; Guidi, Sandra; Emili, Marco; Brigham, Elizabeth; Ciani, Elisabetta; Bartesaghi, Renata

    2015-01-01

    Neurogenesis impairment starting from early developmental stages is a key determinant of intellectual disability in Down syndrome (DS). Previous evidence provided a causal relationship between neurogenesis impairment and malfunctioning of the mitogenic Sonic Hedgehog (Shh) pathway. In particular, excessive levels of AICD (amyloid precursor protein intracellular domain), a cleavage product of the trisomic gene APP (amyloid precursor protein) up-regulate transcription of Ptch1 (Patched1), the Shh receptor that keeps the pathway repressed. Since AICD results from APP cleavage by γ-secretase, the goal of the current study was to establish whether treatment with a γ-secretase inhibitor normalizes AICD levels and restores neurogenesis in trisomic neural precursor cells. We found that treatment with a selective γ-secretase inhibitor (ELND006; ELN) restores proliferation in neurospheres derived from the subventricular zone (SVZ) of the Ts65Dn mouse model of DS. This effect was accompanied by reduction of AICD and Ptch1 levels and was prevented by inhibition of the Shh pathway with cyclopamine. Treatment of Ts65Dn mice with ELN in the postnatal period P3–P15 restored neurogenesis in the SVZ and hippocampus, hippocampal granule cell number and synapse development, indicating a positive impact of treatment on brain development. In addition, in the hippocampus of treated Ts65Dn mice there was a reduction in the expression levels of various genes that are transcriptionally regulated by AICD, including APP, its origin substrate. Inhibitors of γ-secretase are currently envisaged as tools for the cure of Alzheimer's disease because they lower βamyloid levels. Current results provide novel evidence that γ-secretase inhibitors may represent a strategy for the rescue of neurogenesis defects in DS. PMID:26254735

  1. Inhibition of constitutive aryl hydrocarbon receptor (AhR) signaling attenuates androgen independent signaling and growth in (C4-2) prostate cancer cells

    PubMed Central

    Tran, Cindy; Richmond, Oliver; Aaron, LaTayia; Powell, Joann B.

    2013-01-01

    The aryl hydrocarbon receptor is a member of the basic-helix-loop-helix family of transcription factors. AhR mediates the biochemical and toxic effects of a number of polyaromatic hydrocarbons such as 2,3,7,8,-tetrachloro-dibenzo-p-dioxin (TCDD). AhR is widely known for regulating the transcription of drug metabolizing enzymes involved in the xenobiotic metabolism of carcinogens and therapeutic agents, such as cytochrome P450-1B1 (CYP1B1). Additionally, AhR has also been reported to interact with multiple signaling pathways during prostate development. Here we investigate the effect of sustained AhR signaling on androgen receptor function in prostate cancer cells. Immunoblot analysis shows that AhR expression is increased in androgen independent (C4-2) prostate cancer cells when compared to androgen sensitive (LNCaP) cells. RT-PCR studies revealed constitutive AhR signaling in C4-2 cells without the ligand induced activation required in LNCaP cells. A reduction of AhR activity by short RNA mediated silencing in C4-2 cells reduced expression of both AhR and androgen responsive genes. The decrease in androgen responsive genes correlates to a decrease in phosphorylated androgen receptor and androgen receptor expression in the nucleus. Furthermore, the forced decrease in AhR expression resulted in a 50% decline in the growth rate of C4-2 cells. These data indicates that AhR is required to maintain hormone independent signaling and growth by the androgen receptor in C4-2 cells. Collectively, these data provide evidence of a direct role for AhR in androgen independent signaling and provides insight into the molecular mechanisms responsible for sustained androgen receptor signaling in hormone refractory prostate cancer. PMID:23266674

  2. The Sonic hedgehog gradient in the developing limb.

    PubMed

    Tickle, Cheryll; Barker, Heather

    2013-01-01

    A gradient of Sonic hedgehog (Shh) plays a major role in specifying the antero-posterior pattern of structures that develop in the distal part of the vertebrate limb, in particular, the antero-posterior pattern of the digits. Classical embryological experiments identified the polarizing region (or zone of polarizing activity, ZPA), a signaling region at the posterior margin of the early chick wing bud and, consistent with a model in which production of a diffusible morphogen specifies antero-posterior positional information, polarizing region signaling was shown to be dose dependent and long range. It is now well established that the vertebrate hedgehog gene, Sonic hedgehog (Shh), which encodes a secreted protein, is expressed in the polarizing region of the chick wing and that Shh signaling has the same characteristics as polarizing region signaling. Shh expression at the posterior of the early limb bud and the mechanism of Shh signal transduction are conserved among vertebrates including mammals. However, it is unlikely that a simple Shh gradient is responsible for digit pattern formation in mammalian limbs and there is still little understanding of how positional information specified by Shh signaling is encoded and translated into digit anatomy. Alterations in Shh signaling underlie some congenital limb abnormalities and also changes in timing and extent of Shh signaling appear to be related to the evolution of morphological diversity of vertebrate limbs.

  3. Key role for constitutive cyclooxygenase-2 of MDCK cells in basal signaling and response to released ATP.

    PubMed

    Ostrom, R S; Gregorian, C; Drenan, R M; Gabot, K; Rana, B K; Insel, P A

    2001-08-01

    Madin-Darby canine kidney (MDCK) cells release ATP upon mechanical or biochemical activation, initiating P2Y receptor signaling that regulates basal levels of multiple second messengers, including cAMP (J Biol Chem 275: 11735--11739, 2000). Data shown here document inhibition of cAMP formation by Gd(3+) and niflumic acid, channel inhibitors that block ATP release. cAMP production is stimulated via Ca(2+)-dependent activation of cytosolic phospholipase A(2), release of arachidonic acid (AA), and cyclooxygenase (COX)-dependent production of prostaglandins, which activate prostanoid receptors coupled to G(s) and adenylyl cyclase. In the current investigation, we assessed the expression and functional role of the two known isoforms of COX, COX-1 and COX-2. Treatment of cells with either a COX-1-selective inhibitor, SC-560, or COX-2-selective inhibitors, SC-58125 or NS-398, inhibited basal and UTP-stimulated cAMP levels. COX inhibitors also decreased forskolin-stimulated cAMP formation, implying this response is in part attributable to an action of AA metabolites. These findings imply an important role for the inducible form of COX, COX-2, under basal conditions. Indeed, COX-2 expression was readily detectable by immunoblot, and treatments that induce or reduce COX-2 expression in other cells (interleukin-1beta, tumor necrosis factor-alpha, phorbol ester, or dexamethasone) had minimal or no effect on the levels of COX-2 immunoreactivity. RT-PCR using isoform-specific primers detected COX-2 mRNA. We conclude that COX-2 is constitutively expressed in MDCK-D(1) cells and participates in basal and P2Y(2)-mediated signaling, implying a key role for COX-2 in regulation of epithelial cell function. PMID:11443051

  4. Key role for constitutive cyclooxygenase-2 of MDCK cells in basal signaling and response to released ATP.

    PubMed

    Ostrom, R S; Gregorian, C; Drenan, R M; Gabot, K; Rana, B K; Insel, P A

    2001-08-01

    Madin-Darby canine kidney (MDCK) cells release ATP upon mechanical or biochemical activation, initiating P2Y receptor signaling that regulates basal levels of multiple second messengers, including cAMP (J Biol Chem 275: 11735--11739, 2000). Data shown here document inhibition of cAMP formation by Gd(3+) and niflumic acid, channel inhibitors that block ATP release. cAMP production is stimulated via Ca(2+)-dependent activation of cytosolic phospholipase A(2), release of arachidonic acid (AA), and cyclooxygenase (COX)-dependent production of prostaglandins, which activate prostanoid receptors coupled to G(s) and adenylyl cyclase. In the current investigation, we assessed the expression and functional role of the two known isoforms of COX, COX-1 and COX-2. Treatment of cells with either a COX-1-selective inhibitor, SC-560, or COX-2-selective inhibitors, SC-58125 or NS-398, inhibited basal and UTP-stimulated cAMP levels. COX inhibitors also decreased forskolin-stimulated cAMP formation, implying this response is in part attributable to an action of AA metabolites. These findings imply an important role for the inducible form of COX, COX-2, under basal conditions. Indeed, COX-2 expression was readily detectable by immunoblot, and treatments that induce or reduce COX-2 expression in other cells (interleukin-1beta, tumor necrosis factor-alpha, phorbol ester, or dexamethasone) had minimal or no effect on the levels of COX-2 immunoreactivity. RT-PCR using isoform-specific primers detected COX-2 mRNA. We conclude that COX-2 is constitutively expressed in MDCK-D(1) cells and participates in basal and P2Y(2)-mediated signaling, implying a key role for COX-2 in regulation of epithelial cell function.

  5. Sonic Hedgehog regulates thymic epithelial cell differentiation

    PubMed Central

    Saldaña, José Ignacio; Solanki, Anisha; Lau, Ching-In; Sahni, Hemant; Ross, Susan; Furmanski, Anna L.; Ono, Masahiro; Holländer, Georg; Crompton, Tessa

    2016-01-01

    Sonic Hedgehog (Shh) is expressed in the thymus, where it regulates T cell development. Here we investigated the influence of Shh on thymic epithelial cell (TEC) development. Components of the Hedgehog (Hh) signalling pathway were expressed by TEC, and use of a Gli Binding Site-green fluorescence protein (GFP) transgenic reporter mouse demonstrated active Hh-dependent transcription in TEC in the foetal and adult thymus. Analysis of Shh-deficient foetal thymus organ cultures (FTOC) showed that Shh is required for normal TEC differentiation. Shh-deficient foetal thymus contained fewer TEC than wild type (WT), the proportion of medullary TEC was reduced relative to cortical TEC, and cell surface expression of MHC Class II molecules was increased on both cortical and medullary TEC populations. In contrast, the Gli3-deficient thymus, which shows increased Hh-dependent transcription in thymic stroma, had increased numbers of TEC, but decreased cell surface expression of MHC Class II molecules on both cortical and medullary TEC. Neutralisation of endogenous Hh proteins in WT FTOC led to a reduction in TEC numbers, and in the proportion of mature Aire-expressing medullary TEC, but an increase in cell surface expression of MHC Class II molecules on medullary TEC. Likewise, conditional deletion of Shh from TEC in the adult thymus resulted in alterations in TEC differentiation and consequent changes in T cell development. TEC numbers, and the proportion of mature Aire-expressing medullary TEC were reduced, and cell surface expression of MHC Class II molecules on medullary TEC was increased. Differentiation of mature CD4 and CD8 single positive thymocytes was increased, demonstrating the regulatory role of Shh production by TEC on T cell development. Treatment of human thymus explants with recombinant Shh or neutralising anti-Shh antibody indicated that the Hedgehog pathway is also involved in regulation of differentiation from DP to mature SP T cells in the human thymus. PMID

  6. Smoothened regulation in response to Hedgehog stimulation

    PubMed Central

    Jiang, Kai; Jia, Jianhang

    2016-01-01

    The Hedgehog (Hh) signaling pathway play critical roles in embryonic development and adult tissue homeostasis. A critical step in Hh signal transduction is how Hh receptor Patched (Ptc) inhibits the atypical G protein-coupled receptor Smoothened (Smo) in the absence of Hh and how this inhibition is release by Hh stimulation. It is unlikely that Ptc inhibits Smo by direct interaction. Here we discuss how Hh regulates the phosphorylation and ubiquitination of Smo, leading to cell surface and ciliary accumulation of Smo in Drosophila and vertebrate cells, respectively. In addition, we discuss how PI(4)P phospholipid acts in between Ptc and Smo to regulate Smo phosphorylation and activation in response to Hh stimulation. PMID:26973699

  7. Evolution of the vertebrate pth2 (tip39) gene family and the regulation of PTH type-2 Receptor (pth2r) and its endogenous ligand pth2 by Hedgehog signaling in zebrafish development

    PubMed Central

    Bhattacharya, Poulomi; Yan, Yi Lin; Postlethwait, John; Rubin, David A.

    2011-01-01

    In mammals, parathyroid hormone (PTH), secreted by parathyroid glands, increases calcium levels in the blood from reservoirs in bone. While mammals have two PTH receptor genes, PTH1R and PTH2R, zebrafish has three, pth1r, pth2r and pth3r. PTH can activate all three zebrafish Pthrs while PTH2 (alias tuberoinfundibular peptide 39, TIP39) preferentially activates zebrafish and mammalian PTH2Rs. We know little about the roles of the PTH2/PTH2R system in the development of any animal. To determine the roles of PTH2 and PTH2R during vertebrate development, we evaluated their expression patterns in developing zebrafish, observed their phylogenetic and conserved synteny relationships with humans, and described the genomic organization of pth2, pth2r, and pth2r splice variants. Expression studies showed that pth2 is expressed in cells adjacent to the ventral part of the posterior tuberculum in the diencephalon, whereas pth2r is robustly expressed throughout the CNS. Otic vesicles express both pth2 and pth2r, but heart expresses only pth2. Analysis of mutants showed that Hedgehog (Hh) signaling regulates the expression of pth2 transcripts more than that of nearby gnrh2-expressing cells. Genomic analysis showed that a lizard, chicken, and zebra finch lack a PTH2 gene, which is associated with an inversion breakpoint. Likewise, chickens lack PTH2R, while humans lack PTH3R, a case of reciprocally missing ohnologs (paralogs derived from a genome duplication). The considerable evolutionary conservation in genomic structure, synteny relationships, and expression of zebrafish pth2 and pth2r provides a foundation for exploring the endocrine roles of this system in developing vertebrate embryos. PMID:21880859

  8. Non-canonical Hedgehog/AMPK-Mediated Control of Polyamine Metabolism Supports Neuronal and Medulloblastoma Cell Growth.

    PubMed

    D'Amico, Davide; Antonucci, Laura; Di Magno, Laura; Coni, Sonia; Sdruscia, Giulia; Macone, Alberto; Miele, Evelina; Infante, Paola; Di Marcotullio, Lucia; De Smaele, Enrico; Ferretti, Elisabetta; Ciapponi, Laura; Giangaspero, Felice; Yates, John R; Agostinelli, Enzo; Cardinali, Beatrice; Screpanti, Isabella; Gulino, Alberto; Canettieri, Gianluca

    2015-10-12

    Developmental Hedgehog signaling controls proliferation of cerebellar granule cell precursors (GCPs), and its aberrant activation is a leading cause of medulloblastoma. We show here that Hedgehog promotes polyamine biosynthesis in GCPs by engaging a non-canonical axis leading to the translation of ornithine decarboxylase (ODC). This process is governed by AMPK, which phosphorylates threonine 173 of the zinc finger protein CNBP in response to Hedgehog activation. Phosphorylated CNBP increases its association with Sufu, followed by CNBP stabilization, ODC translation, and polyamine biosynthesis. Notably, CNBP, ODC, and polyamines are elevated in Hedgehog-dependent medulloblastoma, and genetic or pharmacological inhibition of this axis efficiently blocks Hedgehog-dependent proliferation of medulloblastoma cells in vitro and in vivo. Together, these data illustrate an auxiliary mechanism of metabolic control by a morphogenic pathway with relevant implications in development and cancer. PMID:26460945

  9. Constitutive activation of CaMKKα signaling is sufficient but not necessary for mTORC1 activation and growth in mouse skeletal muscle

    PubMed Central

    Ferey, Jeremie L. A.; Brault, Jeffrey J.; Smith, Cheryl A. S.

    2014-01-01

    Skeletal muscle loading/overload stimulates the Ca2+-activated, serine/threonine kinase Ca2+/calmodulin-dependent protein kinase kinase-α (CaMKKα); yet to date, no studies have examined whether CaMKKα regulates muscle growth. The purpose of this study was to determine if constitutive activation of CaMKKα signaling could stimulate muscle growth and if so whether CaMKKα is essential for this process. CaMKKα signaling was selectively activated in mouse muscle via expression of a constitutively active form of CaMKKα using in vivo electroporation. After 2 wk, constitutively active CaMKKα expression increased muscle weight (∼10%) and protein content (∼10%), demonstrating that activation of CaMKKα signaling can stimulate muscle growth. To determine if active CaMKKα expression stimulated muscle growth via increased mammalian target of rapamycin complex 1 (mTORC1) signaling and protein synthesis, [3H]phenylalanine incorporation into proteins was assessed with or without the mTORC1 inhibitor rapamycin. Constitutively active CaMKKα increased protein synthesis ∼60%, and this increase was prevented by rapamycin, demonstrating a critical role for mTORC1 in this process. To determine if CaMKKα is essential for growth, muscles from CaMKKα knockout mice were stimulated to hypertrophy via unilateral ablation of synergist muscles (overload). Surprisingly, compared with wild-type mice, muscles from CaMKKα knockout mice exhibited greater growth (∼15%) and phosphorylation of the mTORC1 substrate 70-kDa ribosomal protein S6 kinase (Thr389; ∼50%), demonstrating that CaMKKα is not essential for overload-induced mTORC1 activation or muscle growth. Collectively, these results demonstrate that activation of CaMKKα signaling is sufficient but not necessary for activation of mTORC1 signaling and growth in mouse skeletal muscle. PMID:25159322

  10. Constitutive activation of CaMKKα signaling is sufficient but not necessary for mTORC1 activation and growth in mouse skeletal muscle.

    PubMed

    Ferey, Jeremie L A; Brault, Jeffrey J; Smith, Cheryl A S; Witczak, Carol A

    2014-10-15

    Skeletal muscle loading/overload stimulates the Ca²⁺-activated, serine/threonine kinase Ca²⁺/calmodulin-dependent protein kinase kinase-α (CaMKKα); yet to date, no studies have examined whether CaMKKα regulates muscle growth. The purpose of this study was to determine if constitutive activation of CaMKKα signaling could stimulate muscle growth and if so whether CaMKKα is essential for this process. CaMKKα signaling was selectively activated in mouse muscle via expression of a constitutively active form of CaMKKα using in vivo electroporation. After 2 wk, constitutively active CaMKKα expression increased muscle weight (~10%) and protein content (~10%), demonstrating that activation of CaMKKα signaling can stimulate muscle growth. To determine if active CaMKKα expression stimulated muscle growth via increased mammalian target of rapamycin complex 1 (mTORC1) signaling and protein synthesis, [³H]phenylalanine incorporation into proteins was assessed with or without the mTORC1 inhibitor rapamycin. Constitutively active CaMKKα increased protein synthesis ~60%, and this increase was prevented by rapamycin, demonstrating a critical role for mTORC1 in this process. To determine if CaMKKα is essential for growth, muscles from CaMKKα knockout mice were stimulated to hypertrophy via unilateral ablation of synergist muscles (overload). Surprisingly, compared with wild-type mice, muscles from CaMKKα knockout mice exhibited greater growth (~15%) and phosphorylation of the mTORC1 substrate 70-kDa ribosomal protein S6 kinase (Thr³⁸⁹; ~50%), demonstrating that CaMKKα is not essential for overload-induced mTORC1 activation or muscle growth. Collectively, these results demonstrate that activation of CaMKKα signaling is sufficient but not necessary for activation of mTORC1 signaling and growth in mouse skeletal muscle.

  11. Integrated Genotypic Analysis of Hedgehog-Related Genes Identifies Subgroups of Keratocystic Odontogenic Tumor with Distinct Clinicopathological Features

    PubMed Central

    Shimada, Yasuyuki; Katsube, Ken-ichi; Kabasawa, Yuji; Morita, Kei-ichi; Omura, Ken; Yamaguchi, Akira; Sakamoto, Kei

    2013-01-01

    Keratocystic odontogenic tumor (KCOT) arises as part of Gorlin syndrome (GS) or as a sporadic lesion. Gene mutations and loss of heterozygosity (LOH) of the hedgehog receptor PTCH1 plays an essential role in the pathogenesis of KCOT. However, some KCOT cases lack evidence for gene alteration of PTCH1, suggesting that other genes in the hedgehog pathway may be affected. PTCH2 and SUFU participate in the occurrence of GS-associated tumors, but their roles in KCOT development are unknown. To elucidate the roles of these genes, we enrolled 36 KCOT patients in a study to sequence their entire coding regions of PTCH1, PTCH2 and SUFU. LOH and immunohistochemical expression of these genes, as well as the downstream targets of hedgehog signaling, were examined using surgically-excised KCOT tissues. PTCH1 mutations, including four novel ones, were found in 9 hereditary KCOT patients, but not in sporadic KCOT patients. A pathogenic mutation of PTCH2 or SUFU was not found in any patients. LOH at PTCH1 and SUFU loci correlated with the presence of epithelial budding. KCOT harboring a germline mutation (Type 1) showed nuclear localization of GLI2 and frequent histological findings such as budding and epithelial islands, as well as the highest recurrence rate. KCOT with LOH but without a germline mutation (Type 2) less frequently showed these histological features, and the recurrence rate was lower. KCOT with neither germline mutation nor LOH (Type 3) consisted of two subgroups, Type 3A and 3B, which were characterized by nuclear and cytoplasmic GLI2 localization, respectively. Type 3B rarely exhibited budding and recurrence, behaving as the most amicable entity. The expression patterns of CCND1 and BCL2 tended to correlate with these subgroups. Our data indicates a significant role of PTCH1 and SUFU in the pathogenesis of KCOT, and the genotype-oriented subgroups constitute entities with different potential aggressiveness. PMID:23951062

  12. Hedgehog and Resident Vascular Stem Cell Fate

    PubMed Central

    Mooney, Ciaran J.; Hakimjavadi, Roya; Fitzpatrick, Emma; Kennedy, Eimear; Walls, Dermot; Morrow, David; Redmond, Eileen M.; Cahill, Paul A.

    2015-01-01

    The Hedgehog pathway is a pivotal morphogenic driver during embryonic development and a key regulator of adult stem cell self-renewal. The discovery of resident multipotent vascular stem cells and adventitial progenitors within the vessel wall has transformed our understanding of the origin of medial and neointimal vascular smooth muscle cells (SMCs) during vessel repair in response to injury, lesion formation, and overall disease progression. This review highlights the importance of components of the Hh and Notch signalling pathways within the medial and adventitial regions of adult vessels, their recapitulation following vascular injury and disease progression, and their putative role in the maintenance and differentiation of resident vascular stem cells to vascular lineages from discrete niches within the vessel wall. PMID:26064136

  13. A Hedgehog Survival Pathway in ‘Undead’ Lipotoxic Hepatocytes

    PubMed Central

    Kakisaka, Keisuke; Cazanave, Sophie C.; Werneburg, Nathan W.; Razumilava, Nataliya; Mertens, Joachim C.; Bronk, Steve F.; Gores, Gregory J.

    2012-01-01

    Background & Aims Ballooned hepatocytes in nonalcoholic steatohepatitis (NASH) generate sonic hedgehog (SHH). This observation is consistent with a cellular phenotype in which the cell death program has been initiated but cannot be executed. Our aim was to determine if ballooned hepatocytes have potentially disabled the cell death execution machinery, and if so, can their functional biology be modeled in vitro. Methods Immunohistochemistry was performed on human NASH specimens. In vitro studies were performed using Huh-7 cells with shRNA targeted knockdown of caspase 9 (shC9 cells) or primary hepatocytes from caspase 3−/− mice. Results Ballooned hepatocytes in NASH display diminished expression of the caspase 9. This phenotype was modeled using shC9 cells; these cells were resistant to lipoapoptosis by palmitate (PA) or lysophosphatidylcholine (LPC) despite lipid droplet formation. During lipid loading by either PA or LPC, shC9 cells activate JNK which via AP-1 induces SHH expression. An autocrine hedgehog survival signaling pathway was further delineated in both shC9 and caspase 3−/− cells during lipotoxic stress. Conclusion Ballooned hepatocytes in NASH downregulate caspase 9, a pivotal caspase executing the mitochondrial pathway of apoptosis. Hepatocytes engineered to reduce caspase 9 expression are resistant to lipoapoptosis, in part, due to a hedgehog autocrine survival signaling pathway. PMID:22641094

  14. Primary cilia are critical for Sonic hedgehog-mediated dopaminergic neurogenesis in the embryonic midbrain.

    PubMed

    Gazea, Mary; Tasouri, Evangelia; Tolve, Marianna; Bosch, Viktoria; Kabanova, Anna; Gojak, Christian; Kurtulmus, Bahtiyar; Novikov, Orna; Spatz, Joachim; Pereira, Gislene; Hübner, Wolfgang; Brodski, Claude; Tucker, Kerry L; Blaess, Sandra

    2016-01-01

    Midbrain dopaminergic (mDA) neurons modulate various motor and cognitive functions, and their dysfunction or degeneration has been implicated in several psychiatric diseases. Both Sonic Hedgehog (Shh) and Wnt signaling pathways have been shown to be essential for normal development of mDA neurons. Primary cilia are critical for the development of a number of structures in the brain by serving as a hub for essential developmental signaling cascades, but their role in the generation of mDA neurons has not been examined. We analyzed mutant mouse lines deficient in the intraflagellar transport protein IFT88, which is critical for primary cilia function. Conditional inactivation of Ift88 in the midbrain after E9.0 results in progressive loss of primary cilia, a decreased size of the mDA progenitor domain, and a reduction in mDA neurons. We identified Shh signaling as the primary cause of these defects, since conditional inactivation of the Shh signaling pathway after E9.0, through genetic ablation of Gli2 and Gli3 in the midbrain, results in a phenotype basically identical to the one seen in Ift88 conditional mutants. Moreover, the expansion of the mDA progenitor domain observed when Shh signaling is constitutively activated does not occur in absence of Ift88. In contrast, clusters of Shh-responding progenitors are maintained in the ventral midbrain of the hypomorphic Ift88 mouse mutant, cobblestone. Despite the residual Shh signaling, the integrity of the mDA progenitor domain is severely disturbed, and consequently very few mDA neurons are generated in cobblestone mutants. Our results identify for the first time a crucial role of primary cilia in the induction of mDA progenitors, define a narrow time window in which Shh-mediated signaling is dependent upon normal primary cilia function for this purpose, and suggest that later Wnt signaling-dependent events act independently of primary cilia.

  15. Gli2 protein expression level is a feasible marker of ligand-dependent hedgehog activation in pancreatic neoplasms.

    PubMed

    Sugiyama, Y; Sasajima, J; Mizukami, Y; Koizumi, K; Kawamoto, T; Ono, Y; Karasaki, H; Tanabe, H; Fujiya, M; Kohgo, Y

    2016-06-01

    The hedgehog pathway is known to promote proliferation of pancreatic ductal adenocarcinoma (PDA) and has been shown to restrain tumor progression. To understand how hedgehog causes these effects, we sought to carefully examine protein expression of hedgehog signaling components during different tumor stages. Genetically engineered mice, Pdx1-Cre;LSL-KrasG12D and Pdx1-Cre;LSL-KrasG12D;p53lox/+, were utilized to model distinct phases of tumorigenesis, pancreatic intraepithelial neoplasm (PanIN) and PDA. Human pancreatic specimens of intraductal papillary mucinous neoplasm (IPMN) and PDA were also employed. PanIN and IPMN lesions highly express Sonic Hedgehog, at a level that is slightly higher than that observed in PDA. GLI2 protein is also expressed in both PanIN/IPMN and PDA. Although there was no difference in the nuclear staining, the cytoplasmic GLI2 level in PDA was modest in comparison to that in PanIN/IPMN. Hedgehog interacting protein was strongly expressed in the precursors, whereas the level in PDA was significantly attenuated. There were no differences in expression of Patched1 at early and late stages. Finally, a strong correlation between Sonic Hedgehog and GLI2 staining was found in both human and murine pancreatic tumors. The results indicate that the GLI2 protein level could serve as a feasible marker of ligand-dependent hedgehog activation in pancreatic neoplasms. PMID:27543868

  16. Antiproliferative effects of Dangyuja (Citrus grandis Osbeck) leaves through suppression of constitutive signal transducer and activator of transcription 3 activation in human prostate carcinoma DU145 cells.

    PubMed

    Chiang, Shu Yuan; Kim, Sung-Moo; Kim, Chulwon; Um, Jae-Young; Park, Kyung-Ran; Kim, Seong Won; Lee, Seok-Geun; Jang, Hyeung-Jin; Nam, Dongwoo; Ahn, Kyoo Seok; Kim, Sung-Hoon; Choi, Seung-Hoon; Shim, Bum Sang; Na, Yun-Cheol; Jeong, Eun-Kyung; Cho, Somi K; Ahn, Kwang Seok

    2012-02-01

    Although Dangyuja (Citrus grandis Osbeck) exhibits anti-inflammatory and anticancer activities, its molecular targets and pathways, especially in human prostate cancer cells, are not fully understood. In this study, the antiproliferative effect of Dangyuja leaves through the signal transducer and activator of transcription (STAT) 3 signaling pathway was investigated in human prostate carcinoma DU145 cells. The solvent fractions (n-hexane, chloroform, ethyl acetate, and n-butanol) were obtained from a crude extract (80% methanol extract) of Dangyuja leaves. We first found that the chloroform fraction of Dangyuja leaves (DCF) was the most cytotoxic against DU145 cells. DCF inhibited constitutive STAT3 activation through blocking upstream Janus-like kinase 2 and c-Src. Consistent with STAT3 inactivation, DCF down-regulated the expression of STAT3 target genes, including bcl-2, bcl-xl, and cyclin D1; this correlated with the suppression of proliferation, the accumulation of cell cycle at the sub-G(1) phase, and the induction of apoptosis. Furthermore, DCF exerted a relatively minor effect on the growth of human prostate noncancerous RWPE-1 cells. Nobiletin, a major active constituent of DCF, could induce apoptosis via the suppression of constitutive STAT3 activation. Overall, our results indicate that the anti-inflammatory and anticancer activities previously assigned to DCF may be mediated partially through the suppression of the STAT3 signaling. PMID:22273151

  17. Disruption of Abscisic Acid Signaling Constitutively Activates Arabidopsis Resistance to the Necrotrophic Fungus Plectosphaerella cucumerina1[W

    PubMed Central

    Sánchez-Vallet, Andrea; López, Gemma; Ramos, Brisa; Delgado-Cerezo, Magdalena; Riviere, Marie-Pierre; Llorente, Francisco; Fernández, Paula Virginia; Miedes, Eva; Estevez, José Manuel; Grant, Murray; Molina, Antonio

    2012-01-01

    Plant resistance to necrotrophic fungi is regulated by a complex set of signaling pathways that includes those mediated by the hormones salicylic acid (SA), ethylene (ET), jasmonic acid (JA), and abscisic acid (ABA). The role of ABA in plant resistance remains controversial, as positive and negative regulatory functions have been described depending on the plant-pathogen interaction analyzed. Here, we show that ABA signaling negatively regulates Arabidopsis (Arabidopsis thaliana) resistance to the necrotrophic fungus Plectosphaerella cucumerina. Arabidopsis plants impaired in ABA biosynthesis, such as the aba1-6 mutant, or in ABA signaling, like the quadruple pyr/pyl mutant (pyr1pyl1pyl2pyl4), were more resistant to P. cucumerina than wild-type plants. In contrast, the hab1-1abi1-2abi2-2 mutant impaired in three phosphatases that negatively regulate ABA signaling displayed an enhanced susceptibility phenotype to this fungus. Comparative transcriptomic analyses of aba1-6 and wild-type plants revealed that the ABA pathway negatively regulates defense genes, many of which are controlled by the SA, JA, or ET pathway. In line with these data, we found that aba1-6 resistance to P. cucumerina was partially compromised when the SA, JA, or ET pathway was disrupted in this mutant. Additionally, in the aba1-6 plants, some genes encoding cell wall-related proteins were misregulated. Fourier transform infrared spectroscopy and biochemical analyses of cell walls from aba1-6 and wild-type plants revealed significant differences in their Fourier transform infrared spectratypes and uronic acid and cellulose contents. All these data suggest that ABA signaling has a complex function in Arabidopsis basal resistance, negatively regulating SA/JA/ET-mediated resistance to necrotrophic fungi. PMID:23037505

  18. The dawn of hedgehog inhibitors: Vismodegib.

    PubMed

    Sandhiya, Selvarajan; Melvin, George; Kumar, Srinivasamurthy Suresh; Dkhar, Steven Aibor

    2013-01-01

    Cancer, one of the leading causes of death worldwide is estimated to increase to approximately 13.1 million by 2030. This has amplified the research in oncology towards the exploration of novel targets. Recently there has been lots of interest regarding the hedgehog (Hh) pathway, which plays a significant role in the development of organs and tissues during embryonic and postnatal periods. In a normal person, the Hh signaling pathway is under inhibition and gets activated upon the binding of Hh ligand to a transmembrane receptor called Patched (PTCH1) thus allowing the transmembrane protein, smoothened (SMO) to transfer signals through various proteins. One of the newer drugs namely vismodegib involves the inhibition of Hh pathway and has shown promising results in the treatment of advanced basal-cell carcinoma as well as medulloblastoma. It has been granted approval by US Food and Drug Administration's (US FDA) priority review program on January 30, 2012 for the treatment of advanced basal-cell carcinoma. The drug is also being evaluated in malignancies like medulloblastoma, pancreatic cancer, multiple myeloma, chondrosarcoma and prostate cancer. Moreover various Hh inhibitors namely LDE 225, saridegib, BMS 833923, LEQ 506, PF- 04449913 and TAK-441 are also undergoing phase I and II trials for different neoplasms. Hence this review will describe briefly the Hh pathway and the novel drug vismodegib.

  19. Anomalous dispersions of `hedgehog' particles

    NASA Astrophysics Data System (ADS)

    Bahng, Joong Hwan; Yeom, Bongjun; Wang, Yichun; Tung, Siu On; Hoff, J. Damon; Kotov, Nicholas

    2015-01-01

    Hydrophobic particles in water and hydrophilic particles in oil aggregate, but can form colloidal dispersions if their surfaces are chemically camouflaged with surfactants, organic tethers, adsorbed polymers or other particles that impart affinity for the solvent and increase interparticle repulsion. A different strategy for modulating the interaction between a solid and a liquid uses surface corrugation, which gives rise to unique wetting behaviour. Here we show that this topographical effect can also be used to disperse particles in a wide range of solvents without recourse to chemicals to camouflage the particles' surfaces: we produce micrometre-sized particles that are coated with stiff, nanoscale spikes and exhibit long-term colloidal stability in both hydrophilic and hydrophobic media. We find that these `hedgehog' particles do not interpenetrate each other with their spikes, which markedly decreases the contact area between the particles and, therefore, the attractive forces between them. The trapping of air in aqueous dispersions, solvent autoionization at highly developed interfaces, and long-range electrostatic repulsion in organic media also contribute to the colloidal stability of our particles. The unusual dispersion behaviour of our hedgehog particles, overturning the notion that like dissolves like, might help to mitigate adverse environmental effects of the use of surfactants and volatile organic solvents, and deepens our understanding of interparticle interactions and nanoscale colloidal chemistry.

  20. ALK1 signalling analysis identifies angiogenesis related genes and reveals disparity between TGF-β and constitutively active receptor induced gene expression

    PubMed Central

    Lux, Andreas; Salway, Fiona; Dressman, Holly K; Kröner-Lux, Gabriele; Hafner, Mathias; Day, Philip JR; Marchuk, Douglas A; Garland, John

    2006-01-01

    Background TGF-β1 is an important angiogenic factor involved in the different aspects of angiogenesis and vessel maintenance. TGF-β signalling is mediated by the TβRII/ALK5 receptor complex activating the Smad2/Smad3 pathway. In endothelial cells TGF-β utilizes a second type I receptor, ALK1, activating the Smad1/Smad5 pathway. Consequently, a perturbance of ALK1, ALK5 or TβRII activity leads to vascular defects. Mutations in ALK1 cause the vascular disorder hereditary hemorrhagic telangiectasia (HHT). Methods The identification of ALK1 and not ALK5 regulated genes in endothelial cells, might help to better understand the development of HHT. Therefore, the human microvascular endothelial cell line HMEC-1 was infected with a recombinant constitutively active ALK1 adenovirus, and gene expression was studied by using gene arrays and quantitative real-time PCR analysis. Results After 24 hours, 34 genes were identified to be up-regulated by ALK1 signalling. Analysing ALK1 regulated gene expression after 4 hours revealed 13 genes to be up- and 2 to be down-regulated. Several of these genes, including IL-8, ET-1, ID1, HPTPη and TEAD4 are reported to be involved in angiogenesis. Evaluation of ALK1 regulated gene expression in different human endothelial cell types was not in complete agreement. Further on, disparity between constitutively active ALK1 and TGF-β1 induced gene expression in HMEC-1 cells and primary HUVECs was observed. Conclusion Gene array analysis identified 49 genes to be regulated by ALK1 signalling and at least 14 genes are reported to be involved in angiogenesis. There was substantial agreement between the gene array and quantitative real-time PCR data. The angiogenesis related genes might be potential HHT modifier genes. In addition, the results suggest endothelial cell type specific ALK1 and TGF-β signalling. PMID:16594992

  1. Constitutive and stress-inducible overexpression of a native aquaporin gene (MusaPIP2;6) in transgenic banana plants signals its pivotal role in salt tolerance.

    PubMed

    Sreedharan, Shareena; Shekhawat, Upendra K Singh; Ganapathi, Thumballi R

    2015-05-01

    High soil salinity constitutes a major abiotic stress and an important limiting factor in cultivation of crop plants worldwide. Here, we report the identification and characterization of a aquaporin gene, MusaPIP2;6 which is involved in salt stress signaling in banana. MusaPIP2;6 was firstly identified based on comparative analysis of stressed and non-stressed banana tissue derived EST data sets and later overexpression in transgenic banana plants was performed to study its tangible functions in banana plants. The overexpression of MusaPIP2;6 in transgenic banana plants using constitutive or inducible promoter led to higher salt tolerance as compared to equivalent untransformed control plants. Cellular localization assay performed using transiently transformed onion peel cells indicated that MusaPIP2;6 protein tagged with green fluorescent protein was translocated to the plasma membrane. MusaPIP2;6-overexpressing banana plants displayed better photosynthetic efficiency and lower membrane damage under salt stress conditions. Our results suggest that MusaPIP2;6 is involved in salt stress signaling and tolerance in banana. PMID:25757388

  2. Constitutive and stress-inducible overexpression of a native aquaporin gene (MusaPIP2;6) in transgenic banana plants signals its pivotal role in salt tolerance.

    PubMed

    Sreedharan, Shareena; Shekhawat, Upendra K Singh; Ganapathi, Thumballi R

    2015-05-01

    High soil salinity constitutes a major abiotic stress and an important limiting factor in cultivation of crop plants worldwide. Here, we report the identification and characterization of a aquaporin gene, MusaPIP2;6 which is involved in salt stress signaling in banana. MusaPIP2;6 was firstly identified based on comparative analysis of stressed and non-stressed banana tissue derived EST data sets and later overexpression in transgenic banana plants was performed to study its tangible functions in banana plants. The overexpression of MusaPIP2;6 in transgenic banana plants using constitutive or inducible promoter led to higher salt tolerance as compared to equivalent untransformed control plants. Cellular localization assay performed using transiently transformed onion peel cells indicated that MusaPIP2;6 protein tagged with green fluorescent protein was translocated to the plasma membrane. MusaPIP2;6-overexpressing banana plants displayed better photosynthetic efficiency and lower membrane damage under salt stress conditions. Our results suggest that MusaPIP2;6 is involved in salt stress signaling and tolerance in banana.

  3. Molecular Basis for the Mechanism of Constitutive CBP/p300 Coactivator Recruitment by CRTC1-MAML2 and Its Implications in cAMP Signaling.

    PubMed

    Clark, Michael David; Kumar, Ganesan Senthil; Marcum, Ryan; Luo, Qianyi; Zhang, Yongbo; Radhakrishnan, Ishwar

    2015-09-01

    The cyclic AMP response element-binding protein (CREB) is a signal-dependent transcription factor that exerts its positive effects on gene transcription of a broad range of genes by recruiting coactivators, including CREB-binding protein (CBP), its paralog, p300, and the family of CRTC (CREB-regulated transcriptional coactivators) proteins. Whereas recruitment of CBP/p300 is dependent on CREB phosphorylation at Ser133, recruitment of CRTCs is not. Here we describe how both mechanisms could concurrently drive transcription of CREB targets in a subset of head and neck cancers featuring chromosomal translocations that fuse portions of CRTC1 and CRTC3 genes with that of the Mastermind-like transcriptional coactivator MAML2. We show that a peptide derived from transactivation domain 1 (TAD1) of MAML2 binds to the CBP KIX domain with micromolar affinity. An ∼20-residue segment within this peptide, conserved in MAML2 orthologs and paralogs, binds directly to a KIX surface previously shown to bind to MLL1. The 20-residue MAML2 segment shares sequence similarity with MLL1, especially at those positions in direct contact with KIX, and like MLL1, the segment is characterized by the presence of an ∼10-residue helix. Because CRTC1/3-MAML2 fusion proteins are constitutively nuclear, like CREB, our results suggest constitutive recruitment of CBP/p300 to CREB targets that could be further enhanced by signals that cause CREB Ser133 phosphorylation.

  4. Molecular Basis for the Mechanism of Constitutive CBP/p300 Coactivator Recruitment by CRTC1-MAML2 and its Implications in cAMP Signaling

    PubMed Central

    Clark, Michael David; Kumar, Ganesan Senthil; Marcum, Ryan; Luo, Qianyi; Zhang, Yongbo; Radhakrishnan, Ishwar

    2015-01-01

    The cyclic AMP response element binding protein (CREB) is a signal-dependent transcription factor that exerts its positive effects on gene transcription of a broad range of genes by recruiting coactivators including CREB-binding protein (CBP), its paralog p300, and the family of CRTC (CREB-regulated transcriptional coactivators) proteins. Whereas recruitment of CBP/p300 is dependent on CREB phosphorylation at Ser133, recruitment of CRTCs is not. Here we describe how both mechanisms could concurrently drive transcription of CREB targets in a subset of head and neck cancers featuring chromosomal translocations that fuse portions of CRTC1/3 genes with that of the Mastermind like transcriptional coactivator MAML2. We show that a peptide derived from the transactivation domain 1 (TAD1) of MAML2 binds to the CBP KIX domain with micromolar affinity. A ~20-residue segment within this peptide, conserved in MAML2 orthologs and paralogs, binds directly to a KIX surface previously shown to bind to MLL1. The 20-residue MAML2 segment shares sequence similarity with MLL1, especially at those positions in direct contact with KIX, and like MLL1, the segment is characterized by the presence of a ~10-residue helix. Since CRTC1/3-MAML2 fusion proteins are constitutively nuclear, like CREB, our results suggest constitutive recruitment of CBP/p300 to CREB targets that could be further enhanced by signals that cause CREB Ser133 phosphorylation. PMID:26274502

  5. Constitutive Notch Signaling Causes Abnormal Development of the Oviducts, Abnormal Angiogenesis, and Cyst Formation in Mouse Female Reproductive Tract.

    PubMed

    Ferguson, Lydia; Kaftanovskaya, Elena M; Manresa, Carmen; Barbara, Agustin M; Poppiti, Robert J; Tan, Yingchun; Agoulnik, Alexander I

    2016-03-01

    The Notch signaling pathway is critical for the differentiation of many tissues and organs in the embryo. To study the consequences of Notch1 gain-of-function signaling on female reproductive tract development, we used a cre-loxP strategy and Amhr2-cre transgene to generate mice with conditionally activated Notch1 (Rosa(Notch1)). The Amhr2-cre transgene is expressed in the mesenchyme of developing female reproductive tract and in granulosa cells in the ovary. Double transgenic Amhr2-cre, Rosa(Notch1) females were infertile, whereas control Rosa(Notch1) mice had normal fertility. All female reproductive organs in mutants showed hemorrhaging of blood vessels progressing with age. The mutant oviducts did not develop coiling, and were instead looped around the ovary. There were multiple blockages in the lumen along the oviduct length, creating a barrier for sperm or oocyte passage. Mutant females demonstrated inflamed uteri with increased vascularization and an influx of inflammatory cells. Additionally, older females developed ovarian, oviductal, and uterine cysts. The significant change in gene expression was detected in the mutant oviduct expression of Wnt4, essential for female reproductive tract development. Similar oviductal phenotypes have been detected previously in mice with activated Smo and in beta-catenin, Wnt4, Wnt7a, and Dicer conditional knockouts, indicating a common regulatory pathway disrupted by these genetic abnormalities. PMID:26843448

  6. Proteasome inhibition reverses hedgehog inhibitor and taxane resistance in ovarian cancer.

    PubMed

    Steg, Adam D; Burke, Mata R; Amm, Hope M; Katre, Ashwini A; Dobbin, Zachary C; Jeong, Dae Hoon; Landen, Charles N

    2014-08-30

    The goal of this study was to determine whether combined targeted therapies, specifically those against the Notch, hedgehog and ubiquitin-proteasome pathways, could overcome ovarian cancer chemoresistance. Chemoresistant ovarian cancer cells were exposed to gamma-secretase inhibitors (GSI-I, Compound E) or the proteasome inhibitor bortezomib, alone and in combination with the hedgehog antagonist, LDE225. Bortezomib, alone and in combination with LDE225, was evaluated for effects on paclitaxel efficacy. Cell viability and cell cycle analysis were assessed by MTT assay and propidium iodide staining, respectively. Proteasome activity and gene expression were determined by luminescence assay and qPCR, respectively. Studies demonstrated that GSI-I, but not Compound E, inhibited proteasome activity, similar to bortezomib. Proteasome inhibition decreased hedgehog target genes (PTCH1, GLI1 and GLI2) and increased LDE225 sensitivity in vitro. Bortezomib, alone and in combination with LDE225, increased paclitaxel sensitivity through apoptosis and G2/M arrest. Expression of the multi-drug resistance gene ABCB1/MDR1 was decreased and acetylation of α-tubulin, a marker of microtubule stabilization, was increased following bortezomib treatment. HDAC6 inhibitor tubastatin-a demonstrated that microtubule effects are associated with hedgehog inhibition and sensitization to paclitaxel and LDE225. These results suggest that proteasome inhibition, through alteration of microtubule dynamics and hedgehog signaling, can reverse taxane-mediated chemoresistance. PMID:25216523

  7. Dataset for phenotypic classification of genetic modifiers of smoothened and Hedgehog.

    PubMed

    Marada, Suresh; Truong, Ashley; Ogden, Stacey K

    2016-06-01

    This data article includes supporting information for the research article entitled "The Small GTPase Rap1 is a Modulator of Hedgehog Signaling" [1]. Drosophila wing phenotypes induced by expression of a dominant negative Smoothened (Smo) mutant were cataloged into five distinct classes. Class distributions observed following expression of dominant negative Smo in control and sensitized backgrounds were quantified to serve as references for strength of phenotypic modification. Shifts in class distribution of Hedgehog (Hh) wing phenotypes resulting from introduction of loss-of-function alleles of select Ras family G protein genes and the Hh pathway regulators Fused and Suppressor of Fused are shown. PMID:27014736

  8. Sonic Hedgehog: A Good Gene Gone Bad? Detection and Treatment of Genetic Abnormalities.

    ERIC Educational Resources Information Center

    Yaich, Lauren E.

    2001-01-01

    Presents a case of a baby born with the genetic condition holoprosencephaly in which students explore the "Sonic hedgehog" gene, signal transduction, and the ethics of body and tissue donation. Presents a two-part assignment that features students writing an informed consent document that explains the science behind this congenital abnormality,…

  9. BAM 1 and RECEPTOR-LIKE PROTEIN KINASE 2 constitute a signaling pathway and modulate CLE peptide-triggered growth inhibition in Arabidopsis root.

    PubMed

    Shimizu, Noriko; Ishida, Takashi; Yamada, Masashi; Shigenobu, Shuji; Tabata, Ryo; Kinoshita, Atsuko; Yamaguchi, Katsushi; Hasebe, Mitsuyasu; Mitsumasu, Kanako; Sawa, Shinichiro

    2015-12-01

    Ligand receptor-based signaling is a means of cell-to-cell communication for coordinating developmental and physiological processes in multicellular organisms. In plants, cell-producing meristems utilize this signaling to regulate their activities and ensure for proper development. Shoot and root systems share common requirements for carrying out this process; however, its molecular basis is largely unclear. It has been suggested that synthetic CLV3/EMBRYO SURROUNDING REGION (CLE) peptide shrinks the root meristem through the actions of CLAVATA2 (CLV2) and the RECEPTOR-LIKE PROTEIN KINASE 2 (RPK2) pathway in Arabidopsis thaliana. Our genetic screening for mutations that resist CLE peptide signaling in roots determined that BAM1, which is a member of the leucine-rich repeat receptor-like kinase (LRR-RLK) family, is also involved in this pathway. BAM1 is preferentially expressed in the root tip, including the quiescent center and its surrounding stem cells. Our genetic analysis revealed that BAM1 functions together with RPK2. Using coimmunoprecipitation assay, we showed that BAM1 is capable of forming heteromeric complexes with RPK2. These findings suggest that the BAM1 and RPK2 receptors constitute a signaling pathway that modulates cell proliferation in the root meristem and that related molecules are employed in root and shoot meristems. PMID:26083273

  10. In Vivo Imaging of Hedgehog Pathway Activation with a Nuclear Fluorescent Reporter

    PubMed Central

    Mich, John K.; Payumo, Alexander Y.; Rack, Paul G.; Chen, James K.

    2014-01-01

    The Hedgehog (Hh) pathway is essential for embryonic development and tissue regeneration, and its dysregulation can lead to birth defects and tumorigenesis. Understanding how this signaling mechanism contributes to these processes would benefit from an ability to visualize Hedgehog pathway activity in live organisms, in real time, and with single-cell resolution. We report here the generation of transgenic zebrafish lines that express nuclear-localized mCherry fluorescent protein in a Gli transcription factor-dependent manner. As demonstrated by chemical and genetic perturbations, these lines faithfully report Hedgehog pathway state in individual cells and with high detection sensitivity. They will be valuable tools for studying dynamic Gli-dependent processes in vertebrates and for identifying new chemical and genetic regulators of the Hh pathway. PMID:25068273

  11. Recruitment of a hedgehog regulatory circuit in butterfly eyespot evolution.

    PubMed

    Keys, D N; Lewis, D L; Selegue, J E; Pearson, B J; Goodrich, L V; Johnson, R L; Gates, J; Scott, M P; Carroll, S B

    1999-01-22

    The origin of new morphological characters is a long-standing problem in evolutionary biology. Novelties arise through changes in development, but the nature of these changes is largely unknown. In butterflies, eyespots have evolved as new pattern elements that develop from special organizers called foci. Formation of these foci is associated with novel expression patterns of the Hedgehog signaling protein, its receptor Patched, the transcription factor Cubitus interruptus, and the engrailed target gene that break the conserved compartmental restrictions on this regulatory circuit in insect wings. Redeployment of preexisting regulatory circuits may be a general mechanism underlying the evolution of novelties. PMID:9915699

  12. Recruitment of a hedgehog regulatory circuit in butterfly eyespot evolution.

    PubMed

    Keys, D N; Lewis, D L; Selegue, J E; Pearson, B J; Goodrich, L V; Johnson, R L; Gates, J; Scott, M P; Carroll, S B

    1999-01-22

    The origin of new morphological characters is a long-standing problem in evolutionary biology. Novelties arise through changes in development, but the nature of these changes is largely unknown. In butterflies, eyespots have evolved as new pattern elements that develop from special organizers called foci. Formation of these foci is associated with novel expression patterns of the Hedgehog signaling protein, its receptor Patched, the transcription factor Cubitus interruptus, and the engrailed target gene that break the conserved compartmental restrictions on this regulatory circuit in insect wings. Redeployment of preexisting regulatory circuits may be a general mechanism underlying the evolution of novelties.

  13. Constitutive IDO expression in human cancer is sustained by an autocrine signaling loop involving IL-6, STAT3 and the AHR.

    PubMed

    Litzenburger, Ulrike M; Opitz, Christiane A; Sahm, Felix; Rauschenbach, Katharina J; Trump, Saskia; Winter, Marcus; Ott, Martina; Ochs, Katharina; Lutz, Christian; Liu, Xiangdong; Anastasov, Natasa; Lehmann, Irina; Höfer, Thomas; von Deimling, Andreas; Wick, Wolfgang; Platten, Michael

    2014-02-28

    Indoleamine-2,3-dioxygenase (IDO) inhibitors have entered clinical trials based on their ability to restore anti-tumor immunity in preclinical studies. However, the mechanisms leading to constitutive expression of IDO in human tumors are largely unknown. Here we analyzed the pathways mediating constitutive IDO expression in human cancer. IDO-positive tumor cells and tissues showed basal phosphorylation and acetylation of STAT3 as evidenced by western blotting and immunoprecipitation. Inhibition of IL-6 or STAT3 using siRNA and/or pharmacological inhibitors reduced IDO mRNA and protein expression as well as kynurenine formation. In turn, IDO enzymatic activity activated the AHR as shown by the induction of AHR target genes. IDO-mediated AHR activation induced IL-6 expression, while inhibition or knockdown of the AHR reduced IL-6 expression. IDO activity thus sustains its own expression via an autocrine AHR-IL-6-STAT3 signaling loop. Inhibition of the AHR-IL-6-STAT3 signaling loop restored T-cell proliferation in mixed leukocyte reactions performed in the presence of IDO-expressing human cancer cells. Identification of the IDO-AHR-IL-6-STAT3 signaling loop maintaining IDO expression in human cancers reveals novel therapeutic targets for the inhibition of this core pathway promoting immunosuppression of human cancers. The relevance of the IDO-AHR-IL-6-STAT3 transcriptional circuit is underscored by the finding that high expression of its members IDO, STAT3 and the AHR target gene CYP1B1 is associated with reduced relapse-free survival in lung cancer patients.

  14. Pharmacologic retinoid signaling and physiologic retinoic acid receptor signaling inhibit basal cell carcinoma tumorigenesis.

    PubMed

    So, Po-Lin; Fujimoto, Michele A; Epstein, Ervin H

    2008-05-01

    Basal cell carcinoma (BCC) is the most common human cancer. Patients with basal cell nevus syndrome (Gorlin syndrome) are highly susceptible to developing many BCCs as a result of a constitutive inactivating mutation in one allele of PATCHED 1, which encodes a tumor suppressor that is a major inhibitor of Hedgehog signaling. Dysregulated Hedgehog signaling is a common feature of both hereditary and sporadic BCCs. Recently, we showed remarkable anti-BCC chemopreventive efficacy of tazarotene, a retinoid with retinoic acid receptor (RAR) beta/gamma specificity, in Ptch1+/- mice when treatment was commenced before carcinogenic insults. In this study, we assessed whether the effect of tazarotene against BCC carcinogenesis is sustained after its withdrawal and whether tazarotene is effective against preexisting microscopic BCC lesions. We found that BCCs did not reappear for at least 5 months after topical drug treatment was stopped and that already developed, microscopic BCCs were susceptible to tazarotene inhibition. In vitro, tazarotene inhibited a murine BCC keratinocyte cell line, ASZ001, suggesting that its effect in vivo is by direct action on the actual tumor cells. Down-regulation of Gli1, a target gene of Hedgehog signaling and up-regulation of CRABPII, a target gene of retinoid signaling, were observed with tazarotene treatment. Finally, we investigated the effects of topical applications of other retinoid-related compounds on BCC tumorigenesis in vivo. Tazarotene was the most effective of the preparations studied, and its effect most likely was mediated by RARgamma activation. Furthermore, inhibition of basal RAR signaling in the skin promoted BCC carcinogenesis, suggesting that endogenous RAR signaling restrains BCC growth.

  15. Assessing the osteoblast transcriptome in a model of enhanced bone formation due to constitutive G{sub s}–G protein signaling in osteoblasts

    SciTech Connect

    Wattanachanya, Lalita; Wang, Liping; Millard, Susan M.; Lu, Wei-Dar; O’Carroll, Dylan; Hsiao, Edward C.; Conklin, Bruce R.; Nissenson, Robert A.

    2015-05-01

    G protein-coupled receptor (GPCR) signaling in osteoblasts (OBs) is an important regulator of bone formation. We previously described a mouse model expressing Rs1, an engineered constitutively active G{sub s}-coupled GPCR, under the control of the 2.3 kb Col I promoter. These mice showed a dramatic age-dependent increase in trabecular bone of femurs. Here, we further evaluated the effects of enhanced G{sub s} signaling in OBs on intramembranous bone formation by examining calvariae of 1- and 9-week-old Col1(2.3)/Rs1 mice and characterized the in vivo gene expression specifically occurring in osteoblasts with activated G{sub s} G protein-coupled receptor signaling, at the cellular level rather than in a whole bone. Rs1 calvariae displayed a dramatic increase in bone volume with partial loss of cortical structure. By immunohistochemistry, Osterix was detected in cells throughout the inter-trabecular space while Osteocalcin was expressed predominantly in cells along bone surfaces, suggesting the role of paracrine mediators secreted from OBs driven by 2.3 kb Col I promoter could influence early OB commitment, differentiation, and/or proliferation. Gene expression analysis of calvarial OBs revealed that genes affected by Rs1 signaling include those encoding proteins important for cell differentiation, cytokines and growth factors, angiogenesis, coagulation, and energy metabolism. The set of G{sub s}-GPCRs and other GPCRs that may contribute to the observed skeletal phenotype and candidate paracrine mediators of the effect of G{sub s} signaling in OBs were also determined. Our results identify novel detailed in vivo cellular changes of the anabolic response of the skeleton to G{sub s} signaling in mature OBs. - Highlights: • OB expression of an engineered G{sub s}-coupled receptor dramatically increases bone mass. • We investigated the changes in gene expression in vivo in enhanced OB G{sub s} signaling. • Genes in cell cycle and transcription were increased in

  16. Probing extracellular Sonic hedgehog in neurons

    PubMed Central

    Eitan, Erez; Petralia, Ronald S.; Wang, Ya-Xian; Indig, Fred E.; Mattson, Mark P.

    2016-01-01

    ABSTRACT The bioactivity of Sonic hedgehog (Shh) depends on specific lipid modifications; a palmitate at its N-terminus and a cholesterol at its C-terminus. This dual-lipid modification makes Shh molecules lipophilic, which prevents them from diffusing freely in extracellular space. Multiple lines of evidence indicate that Shh proteins are carried by various forms of extracellular vesicles (EVs). It also has been shown, for instance, that in some tissues Shh proteins are transported to neighboring cells directly via filopodia. We have previously reported that Shh proteins are expressed in hippocampal neurons. In this study we show that, in the hippocampus and cerebellum of postnatal day (P)2 rats, Shh is mostly found near or on the membrane surface of small neurites or filopodia. We also examined cultured hippocampal neurons where we observed noticeable and widespread Shh-immunolabeled vesicles located outside neurons. Through immunoelectron microscopy and biochemical analysis, we find Shh-containing EVs with a wide range of sizes. Unlike robust Shh activity in EVs isolated from cells overexpressing an N-terminal Shh fragment construct, we did not detect measurable Shh activity in EVs purified from the medium of cultured hippocampal neurons. These results suggest the complexity of the transcellular Shh signaling mechanisms in neurons. PMID:27387534

  17. Evolution of the Hedgehog Gene Family

    PubMed Central

    Kumar, S.; Balczarek, K. A.; Lai, Z. C.

    1996-01-01

    Effective intercellular communication is an important feature in the development of multicellular organisms. Secreted hedgehog (hh) protein is essential for both long- and short-range cellular signaling required for body pattern formation in animals. In a molecular evolutionary study, we find that the vertebrate homologs of the Drosophila hh gene arose by two gene duplications: the first gave rise to Desert hh, whereas the second produced the Indian and Sonic hh genes. Both duplications occurred before the emergence of vertebrates and probably before the evolution of chordates. The amino-terminal fragment of the hh precursor, crucial in long- and short-range intercellular communication, evolves two to four times slower than the carboxyl-terminal fragment in both Drosophila hh and its vertebrate homologues, suggesting conservation of mechanism of hh action in animals. A majority of amino acid substitutions in the amino- and carboxyl-terminal fragments are conservative, but the carboxyl-terminal domain has undergone extensive insertion-deletion events while maintaining its autocleavage protease activity. Our results point to similarity of evolutionary constraints among sites of Drosophila and vertebrate hh homologs and suggest some future directions for understanding the role of hh genes in the evolution of developmental complexity in animals. PMID:8849902

  18. Probing extracellular Sonic hedgehog in neurons.

    PubMed

    Eitan, Erez; Petralia, Ronald S; Wang, Ya-Xian; Indig, Fred E; Mattson, Mark P; Yao, Pamela J

    2016-01-01

    The bioactivity of Sonic hedgehog (Shh) depends on specific lipid modifications; a palmitate at its N-terminus and a cholesterol at its C-terminus. This dual-lipid modification makes Shh molecules lipophilic, which prevents them from diffusing freely in extracellular space. Multiple lines of evidence indicate that Shh proteins are carried by various forms of extracellular vesicles (EVs). It also has been shown, for instance, that in some tissues Shh proteins are transported to neighboring cells directly via filopodia. We have previously reported that Shh proteins are expressed in hippocampal neurons. In this study we show that, in the hippocampus and cerebellum of postnatal day (P)2 rats, Shh is mostly found near or on the membrane surface of small neurites or filopodia. We also examined cultured hippocampal neurons where we observed noticeable and widespread Shh-immunolabeled vesicles located outside neurons. Through immunoelectron microscopy and biochemical analysis, we find Shh-containing EVs with a wide range of sizes. Unlike robust Shh activity in EVs isolated from cells overexpressing an N-terminal Shh fragment construct, we did not detect measurable Shh activity in EVs purified from the medium of cultured hippocampal neurons. These results suggest the complexity of the transcellular Shh signaling mechanisms in neurons. PMID:27387534

  19. Hedgehog pathway regulators influence cervical cancer cell proliferation, survival and migration

    SciTech Connect

    Samarzija, Ivana; Beard, Peter

    2012-08-17

    Highlights: Black-Right-Pointing-Pointer Unknown cellular mutations complement papillomavirus-induced carcinogenesis. Black-Right-Pointing-Pointer Hedgehog pathway components are expressed by cervical cancer cells. Black-Right-Pointing-Pointer Hedgehog pathway activators and inhibitors regulate cervical cancer cell biology. Black-Right-Pointing-Pointer Cell immortalization by papillomavirus and activation of Hedgehog are independent. -- Abstract: Human papillomavirus (HPV) infection is considered to be a primary hit that causes cervical cancer. However, infection with this agent, although needed, is not sufficient for a cancer to develop. Additional cellular changes are required to complement the action of HPV, but the precise nature of these changes is not clear. Here, we studied the function of the Hedgehog (Hh) signaling pathway in cervical cancer. The Hh pathway can have a role in a number of cancers, including those of liver, lung and digestive tract. We found that components of the Hh pathway are expressed in several cervical cancer cell lines, indicating that there could exists an autocrine Hh signaling loop in these cells. Inhibition of Hh signaling reduces proliferation and survival of the cervical cancer cells and induces their apoptosis as seen by the up-regulation of the pro-apoptotic protein cleaved caspase 3. Our results indicate that Hh signaling is not induced directly by HPV-encoded proteins but rather that Hh-activating mutations are selected in cells initially immortalized by HPV. Sonic Hedgehog (Shh) ligand induces proliferation and promotes migration of the cervical cancer cells studied. Together, these results indicate pro-survival and protective roles of an activated Hh signaling pathway in cervical cancer-derived cells, and suggest that inhibition of this pathway may be a therapeutic option in fighting cervical cancer.

  20. The Role of Sonic Hedgehog Reemergence During Gastric Cancer

    PubMed Central

    Martin, Jason; Donnelly, Jessica M.; Houghton, JeanMarie

    2016-01-01

    Sonic Hedgehog (Shh) signaling has been extensively studied for its role in developmental biology and cancer biology. The association between Shh and cancer development in general is well established but the functional role of Shh in the development and progression of gastric cancer specifically is largely unknown. Bone marrow-derived stem cells, specifically mesenchymal stem cells (MSCs) infiltrate and engraft into the gastric mucosa in response to the chronic inflammatory environment of Helicobacter infection. In this review, MSC infiltration and changes in the cytokine and cellular profiles of later-stage chronic environments will be tied into their interactions with the Shh pathway. We will discuss how these changes shape tumorigenesis and tumor progression in the gastric mucosa. The current review focuses on the Shh signaling pathway and its role in the development of gastric cancer, specifically in response to Helicobacter pylori infection. We follow with an in-depth discussion of the regulation of the Hedgehog pathway during acute and chronic gastric inflammation with a focus on signaling within the MSC compartment. PMID:20437100

  1. Constitutive Smad signaling and Smad-dependent collagen gene expression in mouse embryonic fibroblasts lacking peroxisome proliferator-activated receptor-{gamma}

    SciTech Connect

    Ghosh, Asish K Wei, Jun; Wu, Minghua; Varga, John

    2008-09-19

    Transforming growth factor-{beta} (TGF-{beta}), a potent inducer of collagen synthesis, is implicated in pathological fibrosis. Peroxisome proliferator-activated receptor-{gamma} (PPAR-{gamma}) is a nuclear hormone receptor that regulates adipogenesis and numerous other biological processes. Here, we demonstrate that collagen gene expression was markedly elevated in mouse embryonic fibroblasts (MEFs) lacking PPAR-{gamma} compared to heterozygous control MEFs. Treatment with the PPAR-{gamma} ligand 15d-PGJ{sub 2} failed to down-regulate collagen gene expression in PPAR-{gamma} null MEFs, whereas reconstitution of these cells with ectopic PPAR-{gamma} resulted in their normalization. Compared to control MEFs, PPAR-{gamma} null MEFs displayed elevated levels of the Type I TGF-{beta} receptor (T{beta}RI), and secreted more TGF-{beta}1 into the media. Furthermore, PPAR-{gamma} null MEFs showed constitutive phosphorylation of cellular Smad2 and Smad3, even in the absence of exogenous TGF-{beta}, which was abrogated by the ALK5 inhibitor SB431542. Constitutive Smad2/3 phosphorylation in PPAR-{gamma} null MEFs was associated with Smad3 binding to its cognate DNA recognition sequences, and interaction with coactivator p300 previously implicated in TGF-{beta} responses. Taken together, these results indicate that loss of PPAR-{gamma} in MEFs is associated with upregulation of collagen synthesis, and activation of intracellular Smad signal transduction, due, at least in part, to autocrine TGF-{beta} stimulation.

  2. Interaction of PACAP with Sonic hedgehog reveals complex regulation of the hedgehog pathway by PKA.

    PubMed

    Niewiadomski, Pawel; Zhujiang, Annie; Youssef, Mary; Waschek, James A

    2013-11-01

    Sonic hedgehog (Shh) signaling is essential for proliferation of cerebellar granule cell progenitors (cGCPs) and its aberrant activation causes a cerebellar cancer medulloblastoma. Pituitary adenylate cyclase activating polypeptide (PACAP) inhibits Shh-driven proliferation of cGCPs and acts as tumor suppressor in murine medulloblastoma. We show that PACAP blocks canonical Shh signaling by a mechanism that involves activation of protein kinase A (PKA) and inhibition of the translocation of the Shh-dependent transcription factor Gli2 into the primary cilium. PKA is shown to play an essential role in inhibiting gene transcription in the absence of Shh, but global PKA activity levels are found to be a poor predictor of the degree of Shh pathway activation. We propose that the core Shh pathway regulates a small compartmentalized pool of PKA in the vicinity of primary cilia. GPCRs that affect global PKA activity levels, such as the PACAP receptor, cooperate with the canonical Shh signal to regulate Gli protein phosphorylation by PKA. This interaction serves to fine-tune the transcriptional and physiological function of the Shh pathway. PMID:23872071

  3. Constitutive hypophosphorylation of extracellular signal-regulated kinases-1/2 and down-regulation of c-Jun in human gastric adenocarcinoma

    SciTech Connect

    Wu, William Ka Kei; Sung, Joseph Joe Yiu; Yu Le; Li Zhijie; Chu, Kent Man; Cho, C.H.

    2008-08-22

    Hyperphosphorylation of extracellular signal-regulated protein kinases-1/2 (ERK1/2) is known to promote cancer cell proliferation. We therefore investigated the constitutive phosphorylation levels of ERK1/2 and the expression of its downstream targets c-Fos, c-Jun, and cyclooxygenase-2 (COX-2) in biopsied human gastric cancer tissues. Results showed that ERK1/2 phosphorylation and c-Jun expression were significantly lowered in gastric cancer compared with the non-cancer adjacent tissues. The expression of c-Fos, however, was not altered while COX-2 was significantly up-regulated. To conclude, we demonstrate that hypophosphorylation of ERK1/2 may occur in gastric cancer. Such discovery may have implication in the application of pathway-directed therapy for this malignant disease.

  4. Dual inhibition of Janus and Src family kinases by novel indirubin derivative blocks constitutively-activated Stat3 signaling associated with apoptosis of human pancreatic cancer cells.

    PubMed

    Nam, Sangkil; Wen, Wei; Schroeder, Anne; Herrmann, Andreas; Yu, Hua; Cheng, Xinlai; Merz, Karl-Heinz; Eisenbrand, Gerhard; Li, Hongzhi; Yuan, Yate-Ching; Jove, Richard

    2013-06-01

    Constitutively-activated JAK/Stat3 or Src/Stat3 signaling plays a crucial role in tumor cell survival, proliferation, angiogenesis and immune suppression. Activated JAK/Stat3 or Src/Stat3 has been validated as a promising molecular target for cancer therapy. However, prolonged inhibition of Src family kinases (SFKs) leads to reactivation of signal transducer and activator of transcript 3 (Stat3) and tumor cell survival through altered JAK/Stat3 interaction. This compensatory feedback suggests that dual inhibition of Janus kinases (JAKs) and SFKs might be a promising strategy for targeting downstream Stat3 signaling in the clinic. In this study, we identify that the natural product derivative E738 is a novel dual inhibitor of JAKs and SFKs. The IC(50) values of E738 against recombinant JAKs and SFKs in vitro are in the ranges of 0.7-74.1 nM and 10.7-263.9 nM, respectively. We observed that phosphorylation of both Jak2 and Src was substantially inhibited in the submicromolar range by E738 in cultured human pancreatic tumor cells, followed by blockade of downstream Stat3 activation. E738 down-regulated expression of the Stat3 target proteins Mcl-1 and survivin, associated with induction of apoptosis. Computational models and molecular dynamics simulations of E738/Tyk2 or E738/Src in silico suggest that E738 inhibits both tyrosine kinase 2 (Tyk2) and Src as an ATP-competitive ligand. Moreover, the planar E738 molecule demonstrates a strong binding affinity in the compact ATP-binding site of Tyk2. In sum, E738 is the first dual inhibitor of JAKs and SFKs, followed by inhibition of Stat3 signaling. Thus, according to in vitro experiments, E738 is a promising new therapeutic agent for human pancreatic cancer treatment by blocking both oncogenic pathways simultaneously.

  5. Hedgehog Receptor Patched Is Expressed in a Tissue and Gestation Specific Manner During Early Human and Murine Development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Hedgehog (Hh) signaling pathway is fundamental for appropriate patterning of nearly every organ system in the developing fetus. The Hh receptor, Patched (Ptc), plays a fundamental role in regulating signal transduction in this pathway. Three main 5 splice forms of the Ptc gene (Ptc1B, Ptc1C, and...

  6. Hedgehog inhibitors from Artocarpus communis and Hyptis suaveolens.

    PubMed

    Arai, Midori A; Uchida, Kyoko; Sadhu, Samir K; Ahmed, Firoj; Koyano, Takashi; Kowithayakorn, Thaworn; Ishibashi, Masami

    2015-08-01

    The hedgehog (Hh) signaling pathway plays crucial roles in cell maintenance and proliferation during embryonic development. Naturally occurring Hh inhibitors were isolated from Artocarpus communis and Hyptis suaveolens using our previously constructed cell-based assay system. Bioactivity guided fractionation led to the isolation of 15 compounds, including seven new compounds (4, 5, 6, 7, and 9-11). The isolated compounds showed cytotoxicity against a cancer cell line (PANC1) in which Hh signaling was abnormally activated. Several compounds (12-14; GLI1 transcriptional inhibition IC50=7.6, 4.7, and 4.0 μM, respectively) inhibited Hh related protein (BCL2) expression. Moreover, compounds 1, 12, and 13 disrupted GLI1 and DNA complex formation.

  7. Hedgehog inhibitors from Artocarpus communis and Hyptis suaveolens.

    PubMed

    Arai, Midori A; Uchida, Kyoko; Sadhu, Samir K; Ahmed, Firoj; Koyano, Takashi; Kowithayakorn, Thaworn; Ishibashi, Masami

    2015-08-01

    The hedgehog (Hh) signaling pathway plays crucial roles in cell maintenance and proliferation during embryonic development. Naturally occurring Hh inhibitors were isolated from Artocarpus communis and Hyptis suaveolens using our previously constructed cell-based assay system. Bioactivity guided fractionation led to the isolation of 15 compounds, including seven new compounds (4, 5, 6, 7, and 9-11). The isolated compounds showed cytotoxicity against a cancer cell line (PANC1) in which Hh signaling was abnormally activated. Several compounds (12-14; GLI1 transcriptional inhibition IC50=7.6, 4.7, and 4.0 μM, respectively) inhibited Hh related protein (BCL2) expression. Moreover, compounds 1, 12, and 13 disrupted GLI1 and DNA complex formation. PMID:26178912

  8. Enhanced Expression of Hedgehog Pathway Proteins in Oral Epithelial Dysplasia.

    PubMed

    Dias, Rosane Borges; Valverde, Ludmila de Faro; Sales, Caroline Brandi Schlaepfer; Guimarães, Vanessa Sousa Nazaré; Cabral, Márcia Grillo; de Aquino Xavier, Flávia Caló; Dos Santos, Jean Nunes; Ramos, Eduardo Antônio Gonçalves; Gurgel Rocha, Clarissa Araújo

    2016-09-01

    The aim of this study was to characterize the profile of the proteins involved in the Hedgehog signaling pathway to aid in the understanding of the pathogenesis of oral epithelial dysplasia (OED). The proteins SHH, PTCH1, HHIP, SUFU, GLI1, and cyclin D1 were evaluated by immunohistochemistry in 25 cases of OED, 4 of non-neoplasic oral mucosa, 8 of inflammatory fibrous hyperplasia and 5 of hyperkeratosis. SHH proteins were predominant in OED cases. Although PTCH1 protein was observed in all cases, this molecule was more highly expressed in OED. The inhibitor protein SUFU was present in OED and HHIP protein was overexpressed in OED. GLI1 proteins were predominantly found in the nuclei of epithelial cells in OED. Basal and suprabasal cells in the epithelial lining were positive for cyclin D1 only in OED. In conclusion, comparative analysis of the proteins involved in the Hedgehog pathway suggests that enhanced expression of these proteins can play an important role in the biological behavior of OED. PMID:26371433

  9. Characterization of two patched receptors for the vertebrate hedgehog protein family

    PubMed Central

    Carpenter, David; Stone, Donna M.; Brush, Jennifer; Ryan, Anne; Armanini, Mark; Frantz, Gretchen; Rosenthal, Arnon; de Sauvage, Frederic J.

    1998-01-01

    The multitransmembrane protein Patched (PTCH) is the receptor for Sonic Hedgehog (Shh), a secreted molecule implicated in the formation of embryonic structures and in tumorigenesis. Current models suggest that binding of Shh to PTCH prevents the normal inhibition of the seven-transmembrane-protein Smoothened (SMO) by PTCH. According to this model, the inhibition of SMO signaling is relieved after mutational inactivation of PTCH in the basal cell nevus syndrome. Recently, PTCH2, a molecule with sequence homology to PTCH, has been identified. To characterize both PTCH molecules with respect to the various Hedgehog proteins, we have isolated the human PTCH2 gene. Biochemical analysis of PTCH and PTCH2 shows that they both bind to all hedgehog family members with similar affinity and that they can form a complex with SMO. However, the expression patterns of PTCH and PTCH2 do not fully overlap. While PTCH is expressed throughout the mouse embryo, PTCH2 is found at high levels in the skin and in spermatocytes. Because Desert Hedgehog (Dhh) is expressed specifically in the testis and is required for germ cell development, it is likely that PTCH2 mediates its activity in vivo. Chromosomal localization of PTCH2 places it on chromosome 1p33–34, a region deleted in some germ cell tumors, raising the possibility that PTCH2 may be a tumor suppressor in Dhh target cells. PMID:9811851

  10. Constitutively Active Mitogen-Activated Protein Kinase Versions Reveal Functions of Arabidopsis MPK4 in Pathogen Defense Signaling[C][W

    PubMed Central

    Berriri, Souha; Garcia, Ana Victoria; dit Frey, Nicolas Frei; Rozhon, Wilfried; Pateyron, Stéphanie; Leonhardt, Nathalie; Montillet, Jean-Luc; Leung, Jeffrey; Hirt, Heribert; Colcombet, Jean

    2012-01-01

    Plant mitogen-activated protein kinases (MAPKs) are involved in important processes, including stress signaling and development. In a functional yeast screen, we identified mutations that render Arabidopsis thaliana MAPKs constitutively active (CA). Importantly, CA-MAPKs maintain their specificity toward known activators and substrates. As a proof-of-concept, Arabidopsis MAPK4 (MPK4) function in plant immunity was investigated. In agreement with the phenotype of mpk4 mutants, CA-MPK4 plants were compromised in pathogen-induced salicylic acid accumulation and disease resistance. MPK4 activity was found to negatively regulate pathogen-associated molecular pattern-induced reactive oxygen species production but had no impact on callose deposition, indicating that CA-MPK4 allows discriminating between processes regulated by MPK4 activity from processes indirectly affected by mpk4 mutation. Finally, MPK4 activity was also found to compromise effector-triggered immunity conditioned by the Toll Interleukin-1 Receptor–nucleotide binding (NB)–Leu-rich repeat (LRR) receptors RPS4 and RPP4 but not by the coiled coil–NB-LRR receptors RPM1 and RPS2. Overall, these data reveal important insights on how MPK4 regulates plant defenses and establishes that CA-MAPKs offer a powerful tool to analyze the function of plant MAPK pathways. PMID:23115249

  11. LRP1 mediates Hedgehog-induced endocytosis of the GPC3–Hedgehog complex

    PubMed Central

    Capurro, Mariana I.; Shi, Wen; Filmus, Jorge

    2013-01-01

    Summary Glypican-3 (GPC3) is a heparan sulfate (HS) proteoglycan that is bound to the cell membrane through a glycosylphosphatidylinositol link. This glypican regulates embryonic growth by inhibiting the hedgehog (Hh) signaling pathway. GPC3 binds Hh and competes with Patched (Ptc), the Hh receptor, for Hh binding. The interaction of Hh with GPC3 triggers the endocytosis and degradation of the GPC3–Hh complex with the consequent reduction of Hh available for binding to Ptc. Currently, the molecular mechanisms by which the GPC3–Hh complex is internalized remains unknown. Here we show that the low-density-lipoprotein receptor-related protein-1 (LRP1) mediates the Hh-induced endocytosis of the GPC3–Hh complex, and that this endocytosis is necessary for the Hh-inhibitory activity of GPC3. Furthermore, we demonstrate that GPC3 binds through its HS chains to LRP1, and that this interaction causes the removal of GPC3 from the lipid rafts domains. PMID:22467855

  12. A miR-221/222-mediated feedback loop maintains constitutive activation of NF-κB and STAT3 signaling in human colorectal cancers

    PubMed Central

    Liu, Sanhong; Sun, Xiaohua; Jiang, Yuhang; Liu, Zhanjie; Cao, Xinwei; Hou, Yingyong; Zhan, Yu; Tao, Yu; Wang, Lunshan; Xu, Chen; Chin, Eugene Y; Shi, Yufang; Siebenlist, Ulrich; Zhang, Xiaoren

    2016-01-01

    Background & Aims Constitutive activation of NF-κB and STAT3 pathways in human colorectal cancers links inflammation to CRC development and progression. However, the underlying mechanisms remain to be elucidated. Here we investigated the roles of miR-221 and miR-222 in regulating both NF-κB and STAT3 activities and colorectal tumorigenesis. Methods miR-221/222 mimics and their inhibitors/sponges were transiently or stably transfected into cells. Dual luciferase reporter assays were utilized to examine the activation of both NF-κB and STAT3 signaling, as well as the regulation of miR-221/222. Quantitative PCR and immunoblot analysis were employed to examine the mRNA and protein expression. MTT assay, flow cytometric analysis and xenotransplant of tumor cells were performed to investigate the CRC cell growth in vitro and in vivo. Results miR-221 and miR-222 positively regulate both NF-κB and STAT3 activities, which in return induce miR-221/222 expression, creating a positive feedback loop in human CRCs. miR-221/222 directly bind to the coding region of RelA, leading to increased RelA mRNA stability. In addition, miR-221/222 reduce ubiquitination of RelA and STAT3 proteins by directly targeting the 3′ UTR of PDLIM2, an E3 ligase for both RelA and STAT3. We demonstrate that disruption of the positive feedback loop suppresses human CRC cell growth in vitro and in vivo. The expression of miR-221/222 correlates with the expression of RelA, STAT3 and PDLIM2 in human CRC clinical samples. Conclusions Our findings define a novel miR-221/222 mediated mechanism underlying constitutive activation of NF-κB and STAT3 pathways in human CRCs and provide a promising therapeutic target for human CRCs. PMID:24931456

  13. Repurposing the antihelmintic mebendazole as a hedgehog inhibitor

    PubMed Central

    Larsen, Andrew R.; Bai, Ren-Yuan; Chung, Jon H.; Borodovsky, Alexandra; Rudin, Charles M.; Riggins, Gregory J.; Bunz, Fred

    2014-01-01

    The hedgehog (Hh) signaling pathway is activated in many types of cancer and therefore presents an attractive target for new anticancer agents. Here we show that mebendazole (MBZ), a benzamidazole with a long history of safe use against nematode infestations and hydatid disease, potently inhibited Hh signaling and slowed the growth of Hh-driven human medulloblastoma cells at clinically attainable concentrations. As an antiparasitic, MBZ avidly binds nematode tubulin and causes inhibition of intestinal microtubule synthesis. In human cells, MBZ suppressed the formation of the primary cilium, a microtubule-based organelle that functions as a signaling hub for Hh pathway activation. The inhibition of Hh signaling by MBZ was unaffected by mutants in the gene that encodes the Hh pathway signaling protein SMO, which are selectively propagated in cell clones that survive treatment with the Hh inhibitor vismodegib. Combination of vismodegib and MBZ resulted in additive Hh signaling inhibition. Because MBZ can be safely administered to adults and children at high doses over extended time periods, we propose that MBZ could be rapidly repurposed and clinically tested as a prospective therapeutic agent for many tumors that are dependent on Hh signaling. PMID:25376612

  14. Twist transition of nematic hyperbolic hedgehogs

    NASA Astrophysics Data System (ADS)

    James, Richard; Fukuda, Jun-ichi

    2014-04-01

    Stability of an idealized hyperbolic hedgehog in a nematic liquid crystal against a twist transition is investigated by extending the methodology of Rüdinger and Stark [Liq. Cryst. 26, 753 (1999), 10.1080/026782999204840], where the hedgehog is confined between two concentric spheres. In the ideal hyperbolic-hedgehog the molecular orientation is assumed to rotate proportionally with respect to the inclination angle, θ (and in the opposite sense). However, when splay, k11, and bend, k33, moduli differ this proportionality is lost and the liquid crystal deforms relative to the ideal with bend and splay. Although slight, these deformations are shown to significantly shift the transition if k11/k33 is small. By increasing the degree of confinement the twist transition can be inhibited, a characteristic both hyperbolic and radial hedgehogs have in common. The twist transition of a hyperbolic defect that accompanies a particle is found to be well predicted by the earlier stability analysis of a thick shell.

  15. Ectoparasites of hedgehogs (Erinaceus concolor) from Turkey.

    PubMed

    Girisgin, Ahmet Onur; Senlik, Bayram; Aydin, Levent; Cirak, Veli Y

    2015-01-01

    Hedgehogs are small, nocturnal, spiny-coated animals that have been growing in popularity as exotic pets. However, these animals are host to a wide variety of viruses, bacteria, fungi and parasites, some of which are of zoonotic character. Thus, because hedgehogs have a potential role to transmit zoonoses including arthropod-borne diseases, we examined them for their ectoparasites. The study was carried out on hedgehogs found dead mainly due to road casualties in the Bursa province of Turkey. The ectoparasites were collected by both insecticide spraying of the body and inspection on a white paper carefully. Totally three species of ticks (Rhipicephalus sanguineus, Hyalomma aegyptium, Haemophysalis parvo) and one flea species (Archeopsylla erinacei) were detected. The prevalence of mixed infestation with both ticks and fleas was 45.5%. Haemaphysalis parva was reported for the first time from hedgehogs (Erinaceus concolor) in Turkey. The occurrence of ectoparasites and their potential role as vectors of certain zoonotic diseases are briefly discussed. PMID:26281445

  16. Click chemistry armed enzyme-linked immunosorbent assay to measure palmitoylation by hedgehog acyltransferase.

    PubMed

    Lanyon-Hogg, Thomas; Masumoto, Naoko; Bodakh, George; Konitsiotis, Antonio D; Thinon, Emmanuelle; Rodgers, Ursula R; Owens, Raymond J; Magee, Anthony I; Tate, Edward W

    2015-12-01

    Hedgehog signaling is critical for correct embryogenesis and tissue development. However, on maturation, signaling is also found to be aberrantly activated in many cancers. Palmitoylation of the secreted signaling protein sonic hedgehog (Shh) by the enzyme hedgehog acyltransferase (Hhat) is required for functional signaling. To quantify this important posttranslational modification, many in vitro Shh palmitoylation assays employ radiolabeled fatty acids, which have limitations in terms of cost and safety. Here we present a click chemistry armed enzyme-linked immunosorbent assay (click-ELISA) for assessment of Hhat activity through acylation of biotinylated Shh peptide with an alkyne-tagged palmitoyl-CoA (coenzyme A) analogue. Click chemistry functionalization of the alkyne tag with azido-FLAG peptide allows analysis through an ELISA protocol and colorimetric readout. This assay format identified the detergent n-dodecyl β-d-maltopyranoside as an improved solubilizing agent for Hhat activity. Quantification of the potency of RU-SKI small molecule Hhat inhibitors by click-ELISA indicated IC50 values in the low- or sub-micromolar range. A stopped assay format was also employed that allows measurement of Hhat kinetic parameters where saturating substrate concentrations exceed the binding capacity of the streptavidin-coated plate. Therefore, click-ELISA represents a nonradioactive method for assessing protein palmitoylation in vitro that is readily expandable to other classes of protein lipidation.

  17. Click chemistry armed enzyme-linked immunosorbent assay to measure palmitoylation by hedgehog acyltransferase

    PubMed Central

    Lanyon-Hogg, Thomas; Masumoto, Naoko; Bodakh, George; Konitsiotis, Antonio D.; Thinon, Emmanuelle; Rodgers, Ursula R.; Owens, Raymond J.; Magee, Anthony I.; Tate, Edward W.

    2015-01-01

    Hedgehog signaling is critical for correct embryogenesis and tissue development. However, on maturation, signaling is also found to be aberrantly activated in many cancers. Palmitoylation of the secreted signaling protein sonic hedgehog (Shh) by the enzyme hedgehog acyltransferase (Hhat) is required for functional signaling. To quantify this important posttranslational modification, many in vitro Shh palmitoylation assays employ radiolabeled fatty acids, which have limitations in terms of cost and safety. Here we present a click chemistry armed enzyme-linked immunosorbent assay (click–ELISA) for assessment of Hhat activity through acylation of biotinylated Shh peptide with an alkyne-tagged palmitoyl-CoA (coenzyme A) analogue. Click chemistry functionalization of the alkyne tag with azido-FLAG peptide allows analysis through an ELISA protocol and colorimetric readout. This assay format identified the detergent n-dodecyl β-d-maltopyranoside as an improved solubilizing agent for Hhat activity. Quantification of the potency of RU-SKI small molecule Hhat inhibitors by click–ELISA indicated IC50 values in the low- or sub-micromolar range. A stopped assay format was also employed that allows measurement of Hhat kinetic parameters where saturating substrate concentrations exceed the binding capacity of the streptavidin-coated plate. Therefore, click–ELISA represents a nonradioactive method for assessing protein palmitoylation in vitro that is readily expandable to other classes of protein lipidation. PMID:26334609

  18. Signaling in colon cancer stem cells.

    PubMed

    Roy, Sanchita; Majumdar, Adhip Pn

    2012-01-01

    : Colorectal cancer is the fourth most common form of cancer worldwide and ranks third among the cancer-related deaths in the US and other Western countries. It occurs with equal frequency in men and women, constituting 10% of new cancer cases in men and 11% in women. Despite recent advancement in therapeutics, the survival rates from metastatic are less than 5%. Growing evidence supports the contention that epithelial cancers including colorectal cancer, the incidence of which increases with aging, are diseases driven by the pluripotent, self-renewing cancer stem cells (CSCs). Dysregulation of Wnt, Notch, Hedgehog and/or TGF-β signaling pathways that are involved in proliferation and maintenance of CSCs leads to the development of CRC. This review focuses on the signaling pathways relevant for CRC to understand the mechanisms leading to tumor progression and therapy resistance, which may help in the development of therapeutic strategies for CRC. PMID:22866952

  19. Development of a monoclonal antibody-based ELISA for the hedgehog inhibitors cyclopamine and cyclopamine-KAAD

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cyclopamine was isolated from Veratrum californicum and identified as the teratogen responsible for severe craniofacial birth defects including cyclops in the offspring of sheep grazing on mountain ranges in central Idaho. More recently, cyclopamine was found to inhibit the hedgehog (Hh) signaling ...

  20. The Hedgehog pathway: role in cell differentiation, polarity and proliferation.

    PubMed

    Jia, Yanfei; Wang, Yunshan; Xie, Jingwu

    2015-02-01

    Hedgehog (Hh) is first described as a genetic mutation that has "spiked" phenotype in the cuticles of Drosophila in later 1970s. Since then, Hh signaling has been implicated in regulation of differentiation, proliferation, tissue polarity, stem cell population and carcinogenesis. The first link of Hh signaling to cancer was established through discovery of genetic mutations of Hh receptor gene PTCH1 being responsible for Gorlin syndrome in 1996. It was later shown that Hh signaling is associated with many types of cancer, including skin, leukemia, lung, brain and gastrointestinal cancers. Another important milestone for the Hh research field is the FDA approval for the clinical use of Hh inhibitor Erivedge/Vismodegib for treatment of locally advanced and metastatic basal cell carcinomas. However, recent clinical trials of Hh signaling inhibitors in pancreatic, colon and ovarian cancer all failed, indicating a real need for further understanding of Hh signaling in cancer. In this review, we will summarize recent progress in the Hh signaling mechanism and its role in human cancer. PMID:25559776

  1. The transcription factor optomotor-blind antagonizes Drosophila haltere growth by repressing decapentaplegic and hedgehog targets.

    PubMed

    Simon, Eléanor; Guerrero, Isabel

    2015-01-01

    In Drosophila, decapentaplegic, which codes for a secreted signaling molecule, is activated by the Hedgehog signaling pathway at the anteroposterior compartment border of the two dorsal primordia; the wing and the haltere imaginal discs. In the wing disc, Decapentaplegic and Hedgehog signaling targets are implicated in cell proliferation and cell survival. However, most of their known targets in the wing disc are not expressed in the haltere disc due to their repression by the Hox gene Ultrabithorax. The T-box gene optomotor-blind escapes this repression in the haltere disc, and therefore is expressed in both the haltere and wing discs. Optomotor-blind is a major player during wing development and its function has been intensely investigated in this tissue, however, its role in haltere development has not been reported so far. Here we show that Optomotor-blind function in the haltere disc differs from that in the wing disc. Unlike its role in the wing, Optomotor-blind does not prevent apoptosis in the haltere but rather limits growth by repressing several Decapentaplegic and Hedgehog targets involved both in wing proliferation and in modulating the spread of morphogens similar to Ultrabithorax function but without disturbing Ultrabithorax expression.

  2. Drosophila genome-wide obesity screen reveals hedgehog as a determinant of brown versus white adipose cell fate.

    PubMed

    Pospisilik, J Andrew; Schramek, Daniel; Schnidar, Harald; Cronin, Shane J F; Nehme, Nadine T; Zhang, Xiaoyun; Knauf, Claude; Cani, Patrice D; Aumayr, Karin; Todoric, Jelena; Bayer, Martina; Haschemi, Arvand; Puviindran, Vijitha; Tar, Krisztina; Orthofer, Michael; Neely, G Gregory; Dietzl, Georg; Manoukian, Armen; Funovics, Martin; Prager, Gerhard; Wagner, Oswald; Ferrandon, Dominique; Aberger, Fritz; Hui, Chi-chung; Esterbauer, Harald; Penninger, Josef M

    2010-01-01

    Over 1 billion people are estimated to be overweight, placing them at risk for diabetes, cardiovascular disease, and cancer. We performed a systems-level genetic dissection of adiposity regulation using genome-wide RNAi screening in adult Drosophila. As a follow-up, the resulting approximately 500 candidate obesity genes were functionally classified using muscle-, oenocyte-, fat-body-, and neuronal-specific knockdown in vivo and revealed hedgehog signaling as the top-scoring fat-body-specific pathway. To extrapolate these findings into mammals, we generated fat-specific hedgehog-activation mutant mice. Intriguingly, these mice displayed near total loss of white, but not brown, fat compartments. Mechanistically, activation of hedgehog signaling irreversibly blocked differentiation of white adipocytes through direct, coordinate modulation of early adipogenic factors. These findings identify a role for hedgehog signaling in white/brown adipocyte determination and link in vivo RNAi-based scanning of the Drosophila genome to regulation of adipocyte cell fate in mammals.

  3. The role of microRNAs during the genesis of medulloblastomas induced by the hedgehog pathway.

    PubMed

    Luo, Xiaoju; Liu, Jun; Cheng, Steven Y

    2011-01-01

    Constitutive hedgehog (Hh) signaling is associated with the genesis of medulloblastomas (MB). The objective of this study is to identify special microRNAs (miRNAs) regulated by the Hh pathway, and to clarify the role of miRNAs during the genesis of MB induced by sustained Hh activation. In the primary screening, we used stem-loop RT-PCR to test the expression of 90 different miRNAs in the wildtype (WT) and Ptc-/- MEF cell lines. In the secondary screening, the miRNAs screened from the first screening were validated in the Sufu-/- MEF cell lines. We then verified the expression of miRNAs both in the normal cerebellar tissues and the MB induced by activated Hh pathway, and examined the expression of the other 21 miRNA members of the miR-154 cluster in the MB and normal cerebellum. In the first screening, 13 miRNAs showed significant differential expression in WT and Ptc-/- MEF cell lines, while 10 of them had significant difference in the Sufu-/- MEF cell line. Compared to the normal mouse cerebellum, only 2 miRNAs in 15 miRNAs were differentially expressed between the MB and normal cerebellar tissues. Among 21 members of the miR-154 cluster, 6 miRNAs were downregulated in the MB. Our study demonstrated that miR-154 may be regulated by the Hh pathway, and the activation of the Hh pathway led to the downregulation of the miR-154 cluster, resulting in the genesis of MB.

  4. Pleiotropic patterning response to activation of Shh signaling in the limb Apical Ectodermal Ridge

    PubMed Central

    Wang, Chi-Kuang Leo; Tsugane, Mizuyo H.; Scranton, Victoria; Kosher, Robert A.; Pierro, Louis J.; Upholt, William B.; Dealy, Caroline N.

    2012-01-01

    Sonic hedgehog (Shh) signaling in the limb plays a central role in coordination of limb patterning and outgrowth. Shh expression in the limb is limited to the cells of the Zone of Polarizing Activity (ZPA), located in posterior limb bud mesoderm. Shh is not expressed by limb ectoderm or AER, but recent studies suggest a role for AER-Shh signaling in limb patterning. Here, we have examined the effects of activation of Shh signaling in the AER. We find that targeted expression of Shh in the AER activates constitutive Shh signaling throughout the AER and subjacent limb mesoderm, and causes a range of limb patterning defects with progressive severity from mild polydactyly, to polysyndactyly with proximal defects, to severe oligodactyly with phocomelia and partial limb ventralization. Our studies emphasize the importance of control of the timing, level and location of Shh pathway signaling for limb AP, PD and DV patterning. PMID:21465622

  5. Cranking in hedgehog models with vector mesons

    NASA Astrophysics Data System (ADS)

    Broniowski, Wojciech; Cohen, Thomas D.

    1986-09-01

    A cranking calculation is performed in a massive SU(2) × SU(2) × U(1) model with valence quarks and the σ, π, ϱ, A and ω mesons. The nucleon moment of inertia, the N-Δ mass splitting and the proton and neutron charge distributions are obtained. The general framework and the specific ansatz for the cranked fields can be used in any hedgehog model with vector mesons. A possible role of η and δ mesons is also discussed.

  6. Hedgehog-mediated paracrine interaction between hepatic stellate cells and marrow-derived mesenchymal stem cells

    SciTech Connect

    Lin Nan Tang Zhaofeng; Deng Meihai; Zhong Yuesi; Lin Jizong; Yang Xuhui; Xiang Peng; Xu Ruiyun

    2008-07-18

    During liver injury, bone marrow-derived mesenchymal stem cells (MSCs) can migrate and differentiate into hepatocytes. Hepatic stellate cell (SC) activation is a pivotal event in the development of liver fibrosis. Therefore, we hypothesized that SCs may play an important role in regulating MSC proliferation and differentiation through the paracrine signaling pathway. We demonstrate that MSCs and SCs both express hedgehog (Hh) pathway components, including its ligands, receptors, and target genes. Transwell co-cultures of SCs and MSCs showed that the SCs produced sonic hedgehog (Shh), which enhanced the proliferation and differentiation of MSCs. These findings demonstrate that SCs indirectly modulate the activity of MSCs in vitro via the Hh pathway, and provide a plausible explanation for the mechanisms of transplanted MSCs in the treatment of liver fibrosis.

  7. Ectopic expression of CsCTR1, a cucumber CTR-like gene, attenuates constitutive ethylene signaling in an Arabidopsis ctr1-1 mutant and expression pattern analysis of CsCTR1 in cucumber (Cucumis sativus).

    PubMed

    Bie, Beibei; Sun, Jin; Pan, Junsong; He, Huanle; Cai, Run

    2014-09-15

    The gaseous plant hormone ethylene regulates many aspects of plant growth, development and responses to the environment. Constitutive triple response 1 (CTR1) is a central regulator involved in the ethylene signal transduction pathway. To obtain a better understanding of this particular pathway in cucumber, the cDNA-encoding CTR1 (designated CsCTR1) was isolated from cucumber. A sequence alignment and phylogenetic analyses revealed that CsCTR1 has a high degree of homology with other plant CTR1 proteins. The ectopic expression of CsCTR1 in the Arabidopsis ctr1-1 mutant attenuates constitutive ethylene signaling of this mutant, suggesting that CsCTR1 indeed performs its function as negative regulator of the ethylene signaling pathway. CsCTR1 is constitutively expressed in all of the examined cucumber organs, including roots, stems, leaves, shoot apices, mature male and female flowers, as well as young fruits. CsCTR1 expression gradually declined during male flower development and increased during female flower development. Additionally, our results indicate that CsCTR1 can be induced in the roots, leaves and shoot apices by external ethylene. In conclusion, this study provides a basis for further studies on the role of CTR1 in the biological processes of cucumber and on the molecular mechanism of the cucumber ethylene signaling pathway.

  8. Hedgehog does not guide migrating Drosophila germ cells

    PubMed Central

    Renault, Andrew D.; Ricardo, Sara; Kunwar, Prabhat S.; Santos, Ana; Starz-Gaiano, Michelle; Stein, Jennifer; Lehmann, Ruth

    2009-01-01

    In many species, the germ cells, precursors of sperm and egg, migrate during embryogenesis. The signals that regulate this migration are thus essential for fertility. In flies, lipid signals have been shown to affect germ cell guidance. In particular, the synthesis of geranylgeranyl pyrophosphate through the 3-hydroxy-3-methyl-glutaryl coenzyme A reductase (Hmgcr) pathway is critical for attracting germ cells to their target tissue. In a genetic analysis of signaling pathways known to affect cell migration of other migratory cells, we failed to find a role for the Hedgehog (Hh) pathway in germ cell migration. However, previous reports had implicated Hh as a germ cell attractant in flies and suggested that Hh signaling is enhanced through the action of the Hmgcr pathway. We therefore repeated several critical experiments and carried out further experiments to test specifically whether Hh is a germ cell attractant in flies. In contrast to previously reported findings and consistent with findings in zebrafish our data do not support the notion that Hh has a direct role in the guidance of migrating germ cells in flies. PMID:19389345

  9. Evolutionary Genomics and Adaptive Evolution of the Hedgehog Gene Family (Shh, Ihh and Dhh) in Vertebrates

    PubMed Central

    Pereira, Joana; Johnson, Warren E.; O’Brien, Stephen J.; Jarvis, Erich D.; Zhang, Guojie; Gilbert, M. Thomas P.; Vasconcelos, Vitor; Antunes, Agostinho

    2014-01-01

    The Hedgehog (Hh) gene family codes for a class of secreted proteins composed of two active domains that act as signalling molecules during embryo development, namely for the development of the nervous and skeletal systems and the formation of the testis cord. While only one Hh gene is found typically in invertebrate genomes, most vertebrates species have three (Sonic hedgehog – Shh; Indian hedgehog – Ihh; and Desert hedgehog – Dhh), each with different expression patterns and functions, which likely helped promote the increasing complexity of vertebrates and their successful diversification. In this study, we used comparative genomic and adaptive evolutionary analyses to characterize the evolution of the Hh genes in vertebrates following the two major whole genome duplication (WGD) events. To overcome the lack of Hh-coding sequences on avian publicly available databases, we used an extensive dataset of 45 avian and three non-avian reptilian genomes to show that birds have all three Hh paralogs. We find suggestions that following the WGD events, vertebrate Hh paralogous genes evolved independently within similar linkage groups and under different evolutionary rates, especially within the catalytic domain. The structural regions around the ion-binding site were identified to be under positive selection in the signaling domain. These findings contrast with those observed in invertebrates, where different lineages that experienced gene duplication retained similar selective constraints in the Hh orthologs. Our results provide new insights on the evolutionary history of the Hh gene family, the functional roles of these paralogs in vertebrate species, and on the location of mutational hotspots. PMID:25549322

  10. Evolutionary genomics and adaptive evolution of the Hedgehog gene family (Shh, Ihh and Dhh) in vertebrates.

    PubMed

    Pereira, Joana; Johnson, Warren E; O'Brien, Stephen J; Jarvis, Erich D; Zhang, Guojie; Gilbert, M Thomas P; Vasconcelos, Vitor; Antunes, Agostinho

    2014-01-01

    The Hedgehog (Hh) gene family codes for a class of secreted proteins composed of two active domains that act as signalling molecules during embryo development, namely for the development of the nervous and skeletal systems and the formation of the testis cord. While only one Hh gene is found typically in invertebrate genomes, most vertebrates species have three (Sonic hedgehog--Shh; Indian hedgehog--Ihh; and Desert hedgehog--Dhh), each with different expression patterns and functions, which likely helped promote the increasing complexity of vertebrates and their successful diversification. In this study, we used comparative genomic and adaptive evolutionary analyses to characterize the evolution of the Hh genes in vertebrates following the two major whole genome duplication (WGD) events. To overcome the lack of Hh-coding sequences on avian publicly available databases, we used an extensive dataset of 45 avian and three non-avian reptilian genomes to show that birds have all three Hh paralogs. We find suggestions that following the WGD events, vertebrate Hh paralogous genes evolved independently within similar linkage groups and under different evolutionary rates, especially within the catalytic domain. The structural regions around the ion-binding site were identified to be under positive selection in the signaling domain. These findings contrast with those observed in invertebrates, where different lineages that experienced gene duplication retained similar selective constraints in the Hh orthologs. Our results provide new insights on the evolutionary history of the Hh gene family, the functional roles of these paralogs in vertebrate species, and on the location of mutational hotspots. PMID:25549322

  11. Generating amphioxus Hedgehog knockout mutants and phenotype analysis.

    PubMed

    Hui, Wang; Guang, Li; Yiquan, Wang

    2015-10-01

    The amphioxus is a promising animal model for evolutionary-developmental studies due to its key position on the animal phylogenetic tree. In the present study, we reported a genetically modified amphioxus strain on the Hedgehog (Hh) gene locus using the TALEN method. The result showed that our TALEN pair injection could bring about 34% mutations in the amphioxus Hh coding region. Further analysis on the F(0) gametic DNA revealed that the mutations had entered into gametes. So, we paired one F(0) male carrying an 8 bp deletion with a wild-type (WT) female, and carefully nursed the F(1) embryos up to adulthood. We then screened F(1) individually via analyzing their genomic DNA from a tiny tail tip, and obtained eight heterozygous mutants from the F(1) offspring. Moreover, our observation on the F(2) embryos generated by mating F(1) mutants also revealed that about 25% of early larvae developed aberrantly with head and tail curving ventrally, agenesis of the mesoblastic tissue under their anterior notochord, and no mouth opening. With the larva growth, deformities (such as twist of head and tail, mouth absent, ventrally localized endostyle and gill slits) became more severe, and eventually those malformed larvae died due to no food intake. Genetic analysis showed that all these deformed embryos were homozygous mutants and the ratio of Hh hetorozygotes vs WT agreed with Mondel's law. WT amphioxus larvae are asymmetric with the mouth on the left and gill slits on the right side. However, the homozygous mutant larvae became left-right symmetric with the gill slits on the ventral side, indicating a conserved role of Hedgehog signaling in establishing the left-right embryonic axis.

  12. Generating amphioxus Hedgehog knockout mutants and phenotype analysis.

    PubMed

    Hui, Wang; Guang, Li; Yiquan, Wang

    2015-10-01

    The amphioxus is a promising animal model for evolutionary-developmental studies due to its key position on the animal phylogenetic tree. In the present study, we reported a genetically modified amphioxus strain on the Hedgehog (Hh) gene locus using the TALEN method. The result showed that our TALEN pair injection could bring about 34% mutations in the amphioxus Hh coding region. Further analysis on the F(0) gametic DNA revealed that the mutations had entered into gametes. So, we paired one F(0) male carrying an 8 bp deletion with a wild-type (WT) female, and carefully nursed the F(1) embryos up to adulthood. We then screened F(1) individually via analyzing their genomic DNA from a tiny tail tip, and obtained eight heterozygous mutants from the F(1) offspring. Moreover, our observation on the F(2) embryos generated by mating F(1) mutants also revealed that about 25% of early larvae developed aberrantly with head and tail curving ventrally, agenesis of the mesoblastic tissue under their anterior notochord, and no mouth opening. With the larva growth, deformities (such as twist of head and tail, mouth absent, ventrally localized endostyle and gill slits) became more severe, and eventually those malformed larvae died due to no food intake. Genetic analysis showed that all these deformed embryos were homozygous mutants and the ratio of Hh hetorozygotes vs WT agreed with Mondel's law. WT amphioxus larvae are asymmetric with the mouth on the left and gill slits on the right side. However, the homozygous mutant larvae became left-right symmetric with the gill slits on the ventral side, indicating a conserved role of Hedgehog signaling in establishing the left-right embryonic axis. PMID:26496756

  13. IFT27 Links the BBSome to IFT for Maintenance of the Ciliary Signaling Compartment

    PubMed Central

    Eguether, Thibaut; San Agustin, Jovenal T.; Keady, Brian T.; Jonassen, Julie A.; Liang, Yinwen; Francis, Richard; Tobita, Kimimasa; Johnson, Colin A.; Abdelhamed, Zakia A.; Lo, Cecilia W.; Pazour, Gregory J.

    2014-01-01

    Vertebrate hedgehog signaling is coordinated by the differential localization of the receptors patched-1 and smoothened in the primary cilium. Cilia assembly is mediated by intraflagellar transport (IFT) and cilia defects disrupt hedgehog signaling, causing many structural birth defects. We generated Ift25 and Ift27 knockout mice and show they have structural birth defects indicative of hedgehog signaling dysfunction. Surprisingly ciliary assembly is not affected, but abnormal hedgehog signaling is observed in conjunction with ciliary accumulation of patched-1 and smoothened. Similarly smoothened accumulates in cilia on cells mutated for BBSome components or the BBS binding protein/regulator Lztfl1. Interestingly, the BBSome and Lztfl1 accumulate to high levels in Ift27 mutant cilia. Since Lztfl1 mutant cells accumulate BBSome but not IFT27 it is likely that Lztfl1 functions downstream of IFT27 to couple the BBSome to the IFT particle for coordinated removal of patched-1 and smoothened from cilia during hedgehog signaling. PMID:25446516

  14. [The Cytoskelrtal Protein Zvxin Interacts with the Hedgehog Receptor Patched].

    PubMed

    Martynova, N U; Ermolina, L V; Eroshkin, F M; Zarayskiy, A G

    2015-01-01

    Earlier, we demonstrated Zyxin influence upon Hedgehog (Hh)-signaling pathway during early patterning of the central neural system (CNS) anlage of the Xenopus laevis embryo. Now we show that Zyxin can physically interact with the transmembrane receptor of Hh, Patched2 (Ptc2). Binding of Hh by this receptor activates signaling pathway, which regulates many events, including numerous types of cell differentiation during the embryonic development. In particular, patterning of the CNS anlage. The ability of Zyxin to interact with Ptc2 have been confirmed by immunoprecipitation experiments, in which we tested mutual binding affinity of Zyxin and Ptc2, as well as mutual affinity of their deletion mutants. As a result, we have established that in Xenopus levis, Zyxin binding to Ptc2 is due to the interaction of Zyxin 2nd LIM-domain (530-590 aa) with the under-membrane region of the cytoplasmic C-terminus of Ptc2 (1159-1412 aa). We have also demonstrated that similar interaction is valid for the homologous regions of the human Zyxin and human Hh receptor, Ptc1. The data obtained allow to hypothesize existence of evolutionary conserved mechanism that modulates Hh-signaling and based on the interaction of Zyxin with Ptc. PMID:27125030

  15. Sonic hedgehog in oral squamous cell carcinoma: An immunohistochemical study

    PubMed Central

    Srinath, Sahana; Iyengar, Asha R; Mysorekar, Vijaya

    2016-01-01

    Background: Recent studies have revealed the involvement of hedgehog (Hh) signaling component in proliferation and invasive behavior of many carcinomas. Aim: This study aims to identify the expression of sonic Hh (SHH) protein of SHH pathway in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC) using SHH (H-160) (Santa Cruz, sc-9042) which could have therapeutic implication in future. Materials and Methods: A total of 250 cases comprising 50 normal oral mucosa, 50 cases of oral epithelial dysplasia, 50 well, 50 moderate and 50 poorly differentiated OSCCs were included in the study. Immunohistochemical evaluation of SHH protein expression was conducted using monoclonal antibody. Interpretation of the expression was done by immunoreactive score of Remmele and Stegner (IRS) scoring method. Statistical Analysis: Chi-Square test was used to analyze the results. Results: The study showed that SHH signaling molecules are highly expressed in OSCC, and their expression was mainly in the cytoplasm of epithelial cells. Conclusion: The SHH signaling component is associated with the pathological parameter in OSCC and oral epithelial dysplasia. PMID:27721600

  16. Pitchfork and Gprasp2 Target Smoothened to the Primary Cilium for Hedgehog Pathway Activation

    PubMed Central

    Jung, Bomi; Padula, Daniela; Burtscher, Ingo; Landerer, Cedric; Lutter, Dominik; Theis, Fabian; Messias, Ana C.; Geerlof, Arie; Sattler, Michael; Kremmer, Elisabeth; Boldt, Karsten; Ueffing, Marius; Lickert, Heiko

    2016-01-01

    The seven-transmembrane receptor Smoothened (Smo) activates all Hedgehog (Hh) signaling by translocation into the primary cilia (PC), but how this is regulated is not well understood. Here we show that Pitchfork (Pifo) and the G protein-coupled receptor associated sorting protein 2 (Gprasp2) are essential components of an Hh induced ciliary targeting complex able to regulate Smo translocation to the PC. Depletion of Pifo or Gprasp2 leads to failure of Smo translocation to the PC and lack of Hh target gene activation. Together, our results identify a novel protein complex that is regulated by Hh signaling and required for Smo ciliary trafficking and Hh pathway activation. PMID:26901434

  17. Pitchfork and Gprasp2 Target Smoothened to the Primary Cilium for Hedgehog Pathway Activation.

    PubMed

    Jung, Bomi; Padula, Daniela; Burtscher, Ingo; Landerer, Cedric; Lutter, Dominik; Theis, Fabian; Messias, Ana C; Geerlof, Arie; Sattler, Michael; Kremmer, Elisabeth; Boldt, Karsten; Ueffing, Marius; Lickert, Heiko

    2016-01-01

    The seven-transmembrane receptor Smoothened (Smo) activates all Hedgehog (Hh) signaling by translocation into the primary cilia (PC), but how this is regulated is not well understood. Here we show that Pitchfork (Pifo) and the G protein-coupled receptor associated sorting protein 2 (Gprasp2) are essential components of an Hh induced ciliary targeting complex able to regulate Smo translocation to the PC. Depletion of Pifo or Gprasp2 leads to failure of Smo translocation to the PC and lack of Hh target gene activation. Together, our results identify a novel protein complex that is regulated by Hh signaling and required for Smo ciliary trafficking and Hh pathway activation. PMID:26901434

  18. Regulation of hedgehog Ligand Expression by the N-End Rule Ubiquitin-Protein Ligase Hyperplastic Discs and the Drosophila GSK3β Homologue, Shaggy

    PubMed Central

    Moncrieff, Sophie; Moncan, Matthieu; Scialpi, Flavia; Ditzel, Mark

    2015-01-01

    Hedgehog (Hh) morphogen signalling plays an essential role in tissue development and homeostasis. While much is known about the Hh signal transduction pathway, far less is known about the molecules that regulate the expression of the hedgehog (hh) ligand itself. Here we reveal that Shaggy (Sgg), the Drosophila melanogaster orthologue of GSK3β, and the N-end Rule Ubiquitin-protein ligase Hyperplastic Discs (Hyd) act together to co-ordinate Hedgehog signalling through regulating hh ligand expression and Cubitus interruptus (Ci) expression. Increased hh and Ci expression within hyd mutant clones was effectively suppressed by sgg RNAi, placing sgg downstream of hyd. Functionally, sgg RNAi also rescued the adult hyd mutant head phenotype. Consistent with the genetic interactions, we found Hyd to physically interact with Sgg and Ci. Taken together we propose that Hyd and Sgg function to co-ordinate hh ligand and Ci expression, which in turn influences important developmental signalling pathways during imaginal disc development. These findings are important as tight temporal/spatial regulation of hh ligand expression underlies its important roles in animal development and tissue homeostasis. When deregulated, hh ligand family misexpression underlies numerous human diseases (e.g., colorectal, lung, pancreatic and haematological cancers) and developmental defects (e.g., cyclopia and polydactyly). In summary, our Drosophila-based findings highlight an apical role for Hyd and Sgg in initiating Hedgehog signalling, which could also be evolutionarily conserved in mammals. PMID:26334301

  19. Ontogenetic Expression of Sonic Hedgehog in the Chicken Subpallium

    PubMed Central

    Bardet, Sylvia M.; Ferran, José L. E.; Sanchez-Arrones, Luisa; Puelles, Luis

    2010-01-01

    Sonic hedgehog (SHH) is a secreted signaling factor that is implicated in the molecular patterning of the central nervous system (CNS), somites, and limbs in vertebrates. SHH has a crucial role in the generation of ventral cell types along the entire rostrocaudal axis of the neural tube. It is secreted early in development by the axial mesoderm (prechordal plate and notochord) and the overlying ventral neural tube. Recent studies clarified the impact of SHH signaling mechanisms on dorsoventral patterning of the spinal cord, but the corresponding phenomena in the rostral forebrain are slightly different and more complex. This notably involves separate Shh expression in the preoptic part of the forebrain alar plate, as well as in the hypothalamic floor and basal plates. The present work includes a detailed spatiotemporal description of the singular alar Shh expression pattern in the rostral preoptic forebrain of chick embryos, comparing it with FoxG1, Dlx5, Nkx2.1, and Nkx2.2 mRNA expression at diverse stages of development. As a result of this mapping, we report a subdivision of the preoptic region in dorsal and ventral zones; only the dorsal part shows Shh expression. The positive area impinges as well upon a median septocommissural preoptic domain. Our study strongly suggests tangential migration of Shh-positive cells from the preoptic region into other subpallial domains, particularly into the pallidal mantle and the intermediate septum. PMID:20700498

  20. Hedgehog activity controls opening of the primary mouth.

    PubMed

    Tabler, Jacqueline M; Bolger, Trióna G; Wallingford, John; Liu, Karen J

    2014-12-01

    To feed or breathe, the oral opening must connect with the gut. The foregut and oral tissues converge at the primary mouth, forming the buccopharyngeal membrane (BPM), a bilayer epithelium. Failure to form the opening between gut and mouth has significant ramifications, and many craniofacial disorders have been associated with defects in this process. Oral perforation is characterized by dissolution of the BPM, but little is known about this process. In humans, failure to form a continuous mouth opening is associated with mutations in Hedgehog (Hh) pathway members; however, the role of Hh in primary mouth development is untested. Here, we show, using Xenopus, that Hh signaling is necessary and sufficient to initiate mouth formation, and that Hh activation is required in a dose-dependent fashion to determine the size of the mouth. This activity lies upstream of the previously demonstrated role for Wnt signal inhibition in oral perforation. We then turn to mouse mutants to establish that SHH and Gli3 are indeed necessary for mammalian mouth development. Our data suggest that Hh-mediated BPM persistence may underlie oral defects in human craniofacial syndromes.

  1. A Single Aspartate Coordinates Two Catalytic Steps in Hedgehog Autoprocessing.

    PubMed

    Xie, Jian; Owen, Timothy; Xia, Ke; Callahan, Brian; Wang, Chunyu

    2016-08-31

    Hedgehog (Hh) signaling is driven by the cholesterol-modified Hh ligand, generated by autoprocessing of Hh precursor protein. Two steps in Hh autoprocessing, N-S acyl shift and transesterification, must be coupled for efficient Hh cholesteroylation and downstream signal transduction. In the present study, we show that a conserved aspartate residue, D46 of the Hh autoprocessing domain, coordinates these two catalytic steps. Mutagenesis demonstrated that D46 suppresses non-native Hh precursor autoprocessing and is indispensable for transesterification with cholesterol. NMR measurements indicated that D46 has a pKa of 5.6, ∼2 units above the expected pKa of aspartate, due to a hydrogen-bond between protonated D46 and a catalytic cysteine residue. However, the deprotonated form of D46 side chain is also essential, because a D46N mutation cannot mediate cholesteroylation. On the basis of these data, we propose that the proton shuttling of D46 side chain mechanistically couples the two steps of Hh cholesteroylation. PMID:27529645

  2. Sonic Hedgehog promotes proliferation of Notch-dependent monociliated choroid plexus tumour cells.

    PubMed

    Li, Li; Grausam, Katie B; Wang, Jun; Lun, Melody P; Ohli, Jasmin; Lidov, Hart G W; Calicchio, Monica L; Zeng, Erliang; Salisbury, Jeffrey L; Wechsler-Reya, Robert J; Lehtinen, Maria K; Schüller, Ulrich; Zhao, Haotian

    2016-04-01

    Aberrant Notch signalling has been linked to many cancers including choroid plexus (CP) tumours, a group of rare and predominantly paediatric brain neoplasms. We developed animal models of CP tumours, by inducing sustained expression of Notch1, that recapitulate properties of human CP tumours with aberrant NOTCH signalling. Whole-transcriptome and functional analyses showed that tumour cell proliferation is associated with Sonic Hedgehog (Shh) in the tumour microenvironment. Unlike CP epithelial cells, which have multiple primary cilia, tumour cells possess a solitary primary cilium as a result of Notch-mediated suppression of multiciliate differentiation. A Shh-driven signalling cascade in the primary cilium occurs in tumour cells but not in epithelial cells. Lineage studies show that CP tumours arise from monociliated progenitors in the roof plate characterized by elevated Notch signalling. Abnormal SHH signalling and distinct ciliogenesis are detected in human CP tumours, suggesting the SHH pathway and cilia differentiation as potential therapeutic avenues.

  3. Sonic Hedgehog promotes proliferation of Notch-dependent monociliated choroid plexus tumour cells

    PubMed Central

    Li, Li; Grausam, Katie B.; Wang, Jun; Lun, Melody P.; Ohli, Jasmin; Lidov, Hart G. W.; Calicchio, Monica L.; Zeng, Erliang; Salisbury, Jeffrey L.; Wechsler-Reya, Robert J.; Lehtinen, Maria K.; Schüller, Ulrich; Zhao, Haotian

    2016-01-01

    Aberrant Notch signaling has been linked to many cancers including choroid plexus (CP) tumours, a group of rare and predominantly pediatric brain neoplasms. We developed animal models of CP tumours by inducing sustained expression of Notch1 that recapitulate properties of human CP tumours with aberrant NOTCH signaling. Whole transcriptome and functional analyses showed that tumour cell proliferation is associated with Sonic Hedgehog (Shh) in the tumour microenvironment. Unlike CP epithelial cells, which have multiple primary cilia, tumour cells possess a solitary primary cilium as a result of Notch-mediated suppression of multiciliate diffferentiation. A Shh-driven signaling cascade in the primary cilium occurs in tumour cells but not in epithelial cells. Lineage studies show that CP tumours arise from mono-ciliated progenitors in the roof plate characterized by elevated Notch signaling. Abnormal SHH signaling and distinct ciliogenesis are detected in human CP tumours, suggesting SHH pathway and cilia differentiation as potential therapeutic avenues. PMID:26999738

  4. Sonic Hedgehog promotes proliferation of Notch-dependent monociliated choroid plexus tumour cells.

    PubMed

    Li, Li; Grausam, Katie B; Wang, Jun; Lun, Melody P; Ohli, Jasmin; Lidov, Hart G W; Calicchio, Monica L; Zeng, Erliang; Salisbury, Jeffrey L; Wechsler-Reya, Robert J; Lehtinen, Maria K; Schüller, Ulrich; Zhao, Haotian

    2016-04-01

    Aberrant Notch signalling has been linked to many cancers including choroid plexus (CP) tumours, a group of rare and predominantly paediatric brain neoplasms. We developed animal models of CP tumours, by inducing sustained expression of Notch1, that recapitulate properties of human CP tumours with aberrant NOTCH signalling. Whole-transcriptome and functional analyses showed that tumour cell proliferation is associated with Sonic Hedgehog (Shh) in the tumour microenvironment. Unlike CP epithelial cells, which have multiple primary cilia, tumour cells possess a solitary primary cilium as a result of Notch-mediated suppression of multiciliate differentiation. A Shh-driven signalling cascade in the primary cilium occurs in tumour cells but not in epithelial cells. Lineage studies show that CP tumours arise from monociliated progenitors in the roof plate characterized by elevated Notch signalling. Abnormal SHH signalling and distinct ciliogenesis are detected in human CP tumours, suggesting the SHH pathway and cilia differentiation as potential therapeutic avenues. PMID:26999738

  5. New Pyrrole Derivatives with Potent Tubulin Polymerization Inhibiting Activity As Anticancer Agents Including Hedgehog-Dependent Cancer

    PubMed Central

    La Regina, Giuseppe; Bai, Ruoli; Coluccia, Antonio; Famiglini, Valeria; Pelliccia, Sveva; Passacantilli, Sara; Mazzoccoli, Carmela; Ruggieri, Vitalba; Sisinni, Lorenza; Bolognesi, Alessio; Rensen, Whilelmina Maria; Miele, Andrea; Nalli, Marianna; Alfonsi, Romina; Di Marcotullio, Lucia; Gulino, Alberto; Brancale, Andrea; Novellino, Ettore; Dondio, Giulio; Vultaggio, Stefania; Varasi, Mario; Mercurio, Ciro; Hamel, Ernest; Lavia, Patrizia; Silvestri, Romano

    2014-01-01

    We synthesized 3-aroyl-1-arylpyrrole (ARAP) derivatives as potential anticancer agents having different substituents at the pendant 1-phenyl ring. Both the 1-phenyl ring and 3-(3,4,5-trimethoxyphenyl)carbonyl moieties were mandatory to achieve potent inhibition of tubulin polymerization, binding of colchicine to tubulin, and cancer cell growth. ARAP 22 showed strong inhibition of the P-glycoprotein-overexpressing NCI-ADR-RES and Messa/Dx5MDR cell lines. Compounds 22 and 27 suppressed in vitro the Hedgehog signaling pathway, strongly reducing luciferase activity in SAG treated NIH3T3 Shh-Light II cells, and inhibited the growth of medulloblastoma D283 cells at nanomolar concentrations. ARAPs 22 and 27 represent a new potent class of tubulin polymerization and cancer cell growth inhibitors with the potential to inhibit the Hedgehog signaling pathway. PMID:25025991

  6. Habenular Neurogenesis in Zebrafish Is Regulated by a Hedgehog, Pax6 Proneural Gene Cascade

    PubMed Central

    Naye, François; Peers, Bernard; Roussigné, Myriam; Blader, Patrick

    2016-01-01

    The habenulae are highly conserved nuclei in the dorsal diencephalon that connect the forebrain to the midbrain and hindbrain. These nuclei have been implicated in a broad variety of behaviours in humans, primates, rodents and zebrafish. Despite this, the molecular mechanisms that control the genesis and differentiation of neural progenitors in the habenulae remain relatively unknown. We have previously shown that, in zebrafish, the timing of habenular neurogenesis is left-right asymmetric and that in the absence of Nodal signalling this asymmetry is lost. Here, we show that habenular neurogenesis requires the homeobox transcription factor Pax6a and the redundant action of two proneural bHLH factors, Neurog1 and Neurod4. We present evidence that Hedgehog signalling is required for the expression of pax6a, which is in turn necessary for the expression of neurog1 and neurod4. Finally, we demonstrate by pharmacological inhibition that Hedgehog signalling is required continuously during habenular neurogenesis and by cell transplantation experiments that pathway activation is required cell autonomously. Our data sheds light on the mechanism underlying habenular development that may provide insights into how Nodal signalling imposes asymmetry on the timing of habenular neurogenesis. PMID:27387288

  7. Histone Methyltransferase NSD2/MMSET Mediates Constitutive NF-κB Signaling for Cancer Cell Proliferation, Survival, and Tumor Growth via a Feed-Forward Loop

    PubMed Central

    Yang, Ping; Guo, Linlang; Duan, Zhijian J.; Tepper, Clifford G.; Xue, Ling; Chen, Xinbin; Kung, Hsing-Jien; Gao, Allen C.

    2012-01-01

    Constitutive NF-κB activation by proinflammatory cytokines plays a major role in cancer progression. However, the underlying mechanism is still unclear. We report here that histone methyltransferase NSD2 (also known as MMSET or WHSC1), a target of bromodomain protein ANCCA/ATAD2, acts as a strong coactivator of NF-κB by directly interacting with NF-κB for activation of target genes, including those for interleukin-6 (IL-6), IL-8, vascular endothelial growth factor A (VEGFA), cyclin D, Bcl-2, and survivin, in castration-resistant prostate cancer (CRPC) cells. NSD2 is recruited to the target gene promoters upon induction and mediates NF-κB activation-associated elevation of histone H3K36me2 and H3K36me3 marks at the promoter, which involves its methylase activity. Interestingly, we found that NSD2 is also critical for cytokine-induced recruitment of NF-κB and acetyltransferase p300 and histone hyperacetylation. Importantly, NSD2 is overexpressed in prostate cancer tumors, and its overexpression correlates with NF-κB activation. Furthermore, NSD2 expression is strongly induced by tumor necrosis factor alpha (TNF-α) and IL-6 via NF-κB and plays a crucial role in tumor growth. These results identify NSD2 to be a key chromatin regulator of NF-κB and mediator of the cytokine autocrine loop for constitutive NF-κB activation and emphasize the important roles played by NSD2 in cancer cell proliferation and survival and tumor growth. PMID:22645312

  8. Cysteine-rich domains related to Frizzled receptors and Hedgehog-interacting proteins

    PubMed Central

    Pei, Jimin; Grishin, Nick V

    2012-01-01

    Frizzled and Smoothened are homologous seven-transmembrane proteins functioning in the Wnt and Hedgehog signaling pathways, respectively. They harbor an extracellular cysteine-rich domain (FZ-CRD), a mobile evolutionary unit that has been found in a number of other metazoan proteins and Frizzled-like proteins in Dictyostelium. Domains distantly related to FZ-CRDs, in Hedgehog-interacting proteins (HHIPs), folate receptors and riboflavin-binding proteins (FRBPs), and Niemann-Pick Type C1 proteins (NPC1s), referred to as HFN-CRDs, exhibit similar structures and disulfide connectivity patterns compared with FZ-CRDs. We used computational analyses to expand the homologous set of FZ-CRDs and HFN-CRDs, providing a better understanding of their evolution and classification. First, FZ-CRD-containing proteins with various domain compositions were identified in several major eukaryotic lineages including plants and Chromalveolata, revealing a wider phylogenetic distribution of FZ-CRDs than previously recognized. Second, two new and distinct groups of highly divergent FZ-CRDs were found by sensitive similarity searches. One of them is present in the calcium channel component Mid1 in fungi and the uncharacterized FAM155 proteins in metazoans. Members of the other new FZ-CRD group occur in the metazoan-specific RECK (reversion-inducing-cysteine-rich protein with Kazal motifs) proteins that are putative tumor suppressors acting as inhibitors of matrix metalloproteases. Finally, sequence and three-dimensional structural comparisons helped us uncover a divergent HFN-CRD in glypicans, which are important morphogen-binding heparan sulfate proteoglycans. Such a finding reinforces the evolutionary ties between the Wnt and Hedgehog signaling pathways and underscores the importance of gene duplications in creating essential signaling components in metazoan evolution. PMID:22693159

  9. Spontaneous neoplasia in four captive greater hedgehog tenrecs (Setifer setosus).

    PubMed

    Khoii, Mina K; Howerth, Elizabeth W; Burns, Roy B; Carmichael, K Paige; Gyimesi, Zoltan S

    2008-09-01

    Little information is available about diseases and pathology of species within the family Tenrecidae, including the greater hedgehog tenrec (Setifer setosus), a Madagascan insectivore. This report summarizes necropsy and histopathologic findings of neoplasia in four captive greater hedgehog tenrecs. Although only four animals are included in this report, neoplasia seems to be a common and significant source of morbidity and mortality in greater hedgehog tenrecs. Types of neoplasia identified include a thyroid follicular-solid carcinoma, two urinary bladder transitional cell carcinomas, uterine endometrial polyps, and multicentric B-cell lymphoma. Due to small sample size, no etiology could be determined, but genetics, viral infection, pesticide treatment, nutrition, or other environmental factors might contribute to the development of neoplasia in this species. This is the first report of neoplasia in greater hedgehog tenrecs.

  10. Impacts of Removing Badgers on Localised Counts of Hedgehogs

    PubMed Central

    Trewby, Iain D.; Young, Richard; McDonald, Robbie A.; Wilson, Gavin J.; Davison, John; Walker, Neil; Robertson, Andrew; Doncaster, C. Patrick; Delahay, Richard J.

    2014-01-01

    Experimental evidence of the interactions among mammalian predators that eat or compete with one another is rare, due to the ethical and logistical challenges of managing wild populations in a controlled and replicated way. Here, we report on the opportunistic use of a replicated and controlled culling experiment (the Randomised Badger Culling Trial) to investigate the relationship between two sympatric predators: European badgers Meles meles and western European hedgehogs Erinaceus europaeus. In areas of preferred habitat (amenity grassland), counts of hedgehogs more than doubled over a 5-year period from the start of badger culling (from 0.9 ha−1 pre-cull to 2.4 ha−1 post-cull), whereas hedgehog counts did not change where there was no badger culling (0.3–0.3 hedgehogs ha−1). This trial provides experimental evidence for mesopredator release as an outcome of management of a top predator. PMID:24736454

  11. Impacts of removing badgers on localised counts of hedgehogs.

    PubMed

    Trewby, Iain D; Young, Richard; McDonald, Robbie A; Wilson, Gavin J; Davison, John; Walker, Neil; Robertson, Andrew; Doncaster, C Patrick; Delahay, Richard J

    2014-01-01

    Experimental evidence of the interactions among mammalian predators that eat or compete with one another is rare, due to the ethical and logistical challenges of managing wild populations in a controlled and replicated way. Here, we report on the opportunistic use of a replicated and controlled culling experiment (the Randomised Badger Culling Trial) to investigate the relationship between two sympatric predators: European badgers Meles meles and western European hedgehogs Erinaceus europaeus. In areas of preferred habitat (amenity grassland), counts of hedgehogs more than doubled over a 5-year period from the start of badger culling (from 0.9 ha-1 pre-cull to 2.4 ha-1 post-cull), whereas hedgehog counts did not change where there was no badger culling (0.3-0.3 hedgehogs ha-1). This trial provides experimental evidence for mesopredator release as an outcome of management of a top predator.

  12. Hedgehog pathway inhibition in advanced basal cell carcinoma: latest evidence and clinical usefulness.

    PubMed

    Silapunt, Sirunya; Chen, Leon; Migden, Michael R

    2016-09-01

    Treatment of locally advanced basal cell carcinomas (laBCCs) with large, aggressive, destructive, and disfiguring tumors, or metastatic disease is challenging. Dysregulation of the Hedgehog (Hh) signaling pathway has been identified in the vast majority of basal cell carcinomas (BCCs). There are two United States Food and Drug Administration (US FDA)-approved Hh pathway inhibitors (HPIs) that exhibit antitumor activity in advanced BCC with an acceptable safety profile. Common adverse effects include muscle spasms, dysgeusia, alopecia, fatigue, nausea and weight loss. PMID:27583029

  13. Hedgehog pathway inhibition in advanced basal cell carcinoma: latest evidence and clinical usefulness

    PubMed Central

    Silapunt, Sirunya; Chen, Leon; Migden, Michael R.

    2016-01-01

    Treatment of locally advanced basal cell carcinomas (laBCCs) with large, aggressive, destructive, and disfiguring tumors, or metastatic disease is challenging. Dysregulation of the Hedgehog (Hh) signaling pathway has been identified in the vast majority of basal cell carcinomas (BCCs). There are two United States Food and Drug Administration (US FDA)-approved Hh pathway inhibitors (HPIs) that exhibit antitumor activity in advanced BCC with an acceptable safety profile. Common adverse effects include muscle spasms, dysgeusia, alopecia, fatigue, nausea and weight loss. PMID:27583029

  14. The Constitutional Amendment Process

    ERIC Educational Resources Information Center

    Chism, Kahlil

    2005-01-01

    This article discusses the constitutional amendment process. Although the process is not described in great detail, Article V of the United States Constitution allows for and provides instruction on amending the Constitution. While the amendment process currently consists of six steps, the Constitution is nevertheless quite difficult to change.…

  15. Zfx facilitates tumorigenesis caused by activation of the Hedgehog pathway.

    PubMed

    Palmer, Colin J; Galan-Caridad, Jose M; Weisberg, Stuart P; Lei, Liang; Esquilin, Jose M; Croft, Gist F; Wainwright, Brandon; Canoll, Peter; Owens, David M; Reizis, Boris

    2014-10-15

    The Hedgehog (Hh) signaling pathway regulates normal development and cell proliferation in metazoan organisms, but its aberrant activation can promote tumorigenesis. Hh-induced tumors arise from various tissues and they may be indolent or aggressive, as is the case with skin basal cell carcinoma (BCC) or cerebellar medulloblastoma, respectively. Little is known about common cell-intrinsic factors that control the development of such diverse Hh-dependent tumors. Transcription factor Zfx is required for the self-renewal of hematopoietic and embryonic stem cells, as well as for the propagation of acute myeloid and T-lymphoblastic leukemias. We report here that Zfx facilitates the development of experimental BCC and medulloblastoma in mice initiated by deletion of the Hh inhibitory receptor Ptch1. Simultaneous deletion of Zfx along with Ptch1 prevented BCC formation and delayed medulloblastoma development. In contrast, Zfx was dispensable for tumorigenesis in a mouse model of glioblastoma. We used genome-wide expression and chromatin-binding analysis in a human medulloblastoma cell line to characterize direct, evolutionarily conserved targets of Zfx, identifying Dis3L and Ube2j1 as two targets required for the growth of the human medulloblastoma cells. Our results establish Zfx as a common cell-intrinsic regulator of diverse Hh-induced tumors, with implications for the definition of new therapeutic targets in these malignancies. PMID:25164012

  16. Sonic hedgehog pathway contributes to gastric cancer cell growth and proliferation.

    PubMed

    Wan, Jianhua; Zhou, Ji; Zhao, Hailong; Wang, Mei; Wei, Zhuanqin; Gao, Hongyan; Wang, Yongzhong; Cui, Hongjuan

    2014-04-01

    The Sonic Hedgehog (Shh) signaling pathway is commonly activated in gastrointestinal cancer. However, our understanding of the Shh pathway in gastric cancer remains limited. Here we examined the effects of cyclopamine, a specific inhibitor of the Shh signaling pathway, on cell growth and proliferation in gastric primary cancer cells GAM-016 and the MKN-45 cell line. The results showed that the Shh signaling molecules SHH, PTCH, SMO, GLI1, and GLI2 were intact and activated in both types of cells. Furthermore, we observed that cyclopamine inhibited gastric cancer cell proliferation through cell cycle arrest and apoptosis. An in vivo study using NOD/SCID mouse xenografts demonstrated that cyclopamine significantly prevented tumor growth and development. Our study indicated that Shh signaling pathway could promote gastric cancer cell proliferation and tumor development, and blocking this pathway may be a potential strategy in gastric cancer treatment.

  17. Hedgehog and Bmp polarise haematopoietic stem cell emergence in the zebrafish dorsal aorta

    PubMed Central

    Wilkinson, Robert N.; Pouget, Claire; Gering, Martin; Russell, Angela J.; Davies, Stephen G.; Kimelman, David; Patient, Roger

    2011-01-01

    Summary Haematopoietic stem cells (HSCs) are first detected in the floor of the embryonic dorsal aorta (DA) and here we investigate the signals that induce the HSC programme there. We show that while continued Hedgehog (Hh) signalling from the overlying midline structures maintains the arterial programme characteristic of the DA roof, a ventral Bmp4 signal induces the blood stem cell programme in the DA floor. This patterning of the DA by Hh and Bmp is the mirror image of that in the neural tube, with Hh favouring dorsal rather than ventral cell types, and Bmp favouring ventral rather than dorsal. With the majority of current data supporting a model whereby HSCs derive from arterial endothelium, our data identifies the signal driving this conversion. These findings are important for the production of HSCs from embryonic stem cells and establish a paradigm for the development of adult stem cells. PMID:19531361

  18. Rickettsiae in arthropods collected from the North African Hedgehog (Atelerix algirus) and the desert hedgehog (Paraechinus aethiopicus) in Algeria.

    PubMed

    Khaldi, Mourad; Socolovschi, Cristina; Benyettou, Meryam; Barech, Ghania; Biche, Mohamed; Kernif, Tahar; Raoult, Didier; Parola, Philippe

    2012-03-01

    Hedgehogs have become a popular pet despite their potential role in zoonotic disease transmission. We conducted an entomological study in a mountainous region of northeast Algeria in which we collected 387 fleas (Archeopsylla erinacei) and 342 ticks (Rhipicephalus sanguineus and Haemaphysalis erinacei) from Paraechinus aethiopicus and Atelerix algirus hedgehogs. Of the hedgehogs sampled, 77.7% and 91% were infested with fleas and ticks, respectively. Significantly more ticks and fleas were collected from A. algirus than from P. aethiopicus. Rickettsia felis was detected in 95.5% of fleas and R. massiliae was detected in 6.25% of Rh. sanguineus ticks by molecular tools. A new Rickettsia species of the spotted fever group was detected in 11.25% of Rh. sanguineus and in 77% of H. erinacei ticks. Overall, we show that hedgehogs can act as hosts for ectoparasites infected with several rickettsial agents. These data justify a more detailed investigation of animal reservoirs for Rickettsiae. PMID:22222114

  19. Developmental pathways: Sonic hedgehog-Patched-GLI.

    PubMed Central

    Walterhouse, D O; Yoon, J W; Iannaccone, P M

    1999-01-01

    Developmental pathways are networks of genes that act coordinately to establish the body plan. Disruptions of genes in one pathway can have effects in related pathways and may result in serious dysmorphogenesis or cancer. Environmental exposures can be associated with poor pregnancy outcomes, including dysmorphic offspring or children with a variety of diseases. An important goal of environmental science should be reduction of these poor outcomes. This will require an understanding of the genes affected by specific exposures and the consequence of alterations in these genes or their products, which in turn will require an understanding of the pathways critical in development. The ligand Sonic hedgehog, the receptors Patched and Smoothened, and the GLI family of transcription factors represent one such pathway. This pathway illustrates several operating principles important in the consideration of developmental consequences of environmental exposures to toxins. Images Figure 1 Figure 2 PMID:10064544

  20. Sonic hedgehog functions as a mitogen during bell stage of odontogenesis.

    PubMed

    Wu, Changshan; Shimo, Tsuyoshi; Liu, Mufei; Pacifici, Maurizio; Koyama, Eiki

    2003-01-01

    Epithelial-mesenchymal interactions are required for tissue growth and gene expression patterns during odontogenesis. We showed previously that Sonic hedgehog (SHH) is detectable in both dental epithelium and mesenchyme, while Shh transcripts are present in dental epithelium only, suggesting that SHH functions as an autocrine signal in epithelium and a paracrine signal in mesenchyme. This hypothesis was tested here. We found by in situ hybridization that the SHH autocrine receptor Ptch-2 is indeed expressed in dental epithelium whereas the paracrine receptor Ptc is expressed in mesenchyme. Bovine bell stage tooth germs were microsurgically separated into epithelial and mesenchymal portions and the resulting tissue fragments were organ-cultured. In epithelium fragments cultured by themselves, gene expression of Shh and Gli-1 (a putative transcriptional mediator of hedgehog signaling) was significantly decreased in both inner dental epithelium and stratum intermedium layers; this was accompanied by a sharp drop in epithelial cell proliferation. However, in companion control tissue fragments containing both epithelium and mesenchyme, Shh and Gli-1 expression as well as cell proliferation were maintained. Treatment of dental epithelial or mesenchymal cell populations in monolayer cultures with exogenous recombinant SHH stimulated cell proliferation. Together, the data provide clear evidence that Shh is synthesized by dental epithelium, reaches the underlying mesenchyme, and appears to act as an autocrine mitogen for epithelial cells and a paracrine mitogen for mesenchymal cells, thus exerting crucial functions in tooth germ growth, morphogenesis, and tissue-tissue interactions of bell stage of odontogenesis.

  1. The Hedgehog Inhibitor Cyclopamine Reduces β-Catenin-Tcf Transcriptional Activity, Induces E-Cadherin Expression, and Reduces Invasion in Colorectal Cancer Cells

    PubMed Central

    Qualtrough, David; Rees, Phil; Speight, Beverley; Williams, Ann C.; Paraskeva, Christos

    2015-01-01

    Colorectal cancer is a major global health problem resulting in over 600,000 deaths world-wide every year with the majority of these due to metastatic disease. Wnt signalling, and more specifically β-catenin-related transcription, has been shown to drive both tumorigenesis and the metastatic process in colorectal neoplasia, yet its complex interactions with other key signalling pathways, such as hedgehog, remain to be elucidated. We have previously shown that the Hedgehog (HH) signalling pathway is active in cells from colorectal tumours, and that inhibition of the pathway with cyclopamine induces apoptosis. We now show that cyclopamine treatment reduces β-catenin related transcription in colorectal cancer cell lines, and that this effect can be reversed by addition of Sonic Hedgehog protein. We also show that cyclopamine concomitantly induces expression of the tumour suppressor and prognostic indicator E-cadherin. Consistent with a role for HH in regulating the invasive potential we show that cyclopamine reduces the expression of transcription factors (Slug, Snail and Twist) associated with the epithelial-mesenchymal transition and reduces