101
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Ermilov AN, Kumari A, Li L, Joiner AM, Grachtchouk MA, Allen BL, Dlugosz AA, Mistretta CM. Maintenance of Taste Organs Is Strictly Dependent on Epithelial Hedgehog/GLI Signaling. PLoS Genet 2016; 12:e1006442. [PMID: 27893742 PMCID: PMC5125561 DOI: 10.1371/journal.pgen.1006442] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 10/21/2016] [Indexed: 12/12/2022] Open
Abstract
For homeostasis, lingual taste papilla organs require regulation of epithelial cell survival and renewal, with sustained innervation and stromal interactions. To investigate a role for Hedgehog/GLI signaling in adult taste organs we used a panel of conditional mouse models to manipulate GLI activity within epithelial cells of the fungiform and circumvallate papillae. Hedgehog signaling suppression rapidly led to taste bud loss, papilla disruption, and decreased proliferation in domains of papilla epithelium that contribute to taste cells. Hedgehog responding cells were eliminated from the epithelium but retained in the papilla stromal core. Despite papilla disruption and loss of taste buds that are a major source of Hedgehog ligand, innervation to taste papillae was maintained, and not misdirected, even after prolonged GLI blockade. Further, vimentin-positive fibroblasts remained in the papilla core. However, retained innervation and stromal cells were not sufficient to maintain taste bud cells in the context of compromised epithelial Hedgehog signaling. Importantly taste organ disruption after GLI blockade was reversible in papillae that retained some taste bud cell remnants where reactivation of Hedgehog signaling led to regeneration of papilla epithelium and taste buds. Therefore, taste bud progenitors were either retained during epithelial GLI blockade or readily repopulated during recovery, and were poised to regenerate taste buds once Hedgehog signaling was restored, with innervation and papilla connective tissue elements in place. Our data argue that Hedgehog signaling is essential for adult tongue tissue maintenance and that taste papilla epithelial cells represent the key targets for physiologic Hedgehog-dependent regulation of taste organ homeostasis. Because disruption of GLI transcriptional activity in taste papilla epithelium is sufficient to drive taste organ loss, similar to pharmacologic Hedgehog pathway inhibition, the findings suggest that taste alterations in cancer patients using systemic Hedgehog pathway inhibitors result principally from interruption of signaling activity in taste papillae.
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Affiliation(s)
- Alexandre N Ermilov
- Department of Dermatology, Medical School, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Archana Kumari
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Libo Li
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Ariell M Joiner
- Department of Cell and Developmental Biology, Medical School, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Marina A Grachtchouk
- Department of Dermatology, Medical School, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Benjamin L Allen
- Department of Cell and Developmental Biology, Medical School, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Andrzej A Dlugosz
- Department of Dermatology, Medical School, University of Michigan, Ann Arbor, Michigan, United States of America.,Department of Cell and Developmental Biology, Medical School, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Charlotte M Mistretta
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
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102
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Chang CF, Chang YT, Millington G, Brugmann SA. Craniofacial Ciliopathies Reveal Specific Requirements for GLI Proteins during Development of the Facial Midline. PLoS Genet 2016; 12:e1006351. [PMID: 27802276 PMCID: PMC5089743 DOI: 10.1371/journal.pgen.1006351] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 09/08/2016] [Indexed: 11/19/2022] Open
Abstract
Ciliopathies represent a broad class of disorders that affect multiple organ systems. The craniofacial complex is among those most severely affected when primary cilia are not functional. We previously reported that loss of primary cilia on cranial neural crest cells, via a conditional knockout of the intraflagellar transport protein KIF3a, resulted in midfacial widening due to a gain of Hedgehog (HH) activity. Here, we examine the molecular mechanism of how a loss of primary cilia can produce facial phenotypes associated with a gain of HH function. We show that loss of intraflagellar transport proteins (KIF3a or IFT88) caused aberrant GLI processing such that the amount of GLI3FL and GLI2FL was increased, thus skewing the ratio of GLIFL to GLIR in favor of the FL isoform. Genetic addition of GLI3R partially rescued the ciliopathic midfacial widening. Interestingly, despite several previous studies suggesting midfacial development relies heavily on GLI3R activity, the conditional loss of GLI3 alone did not reproduce the ciliopathic phenotype. Only the combined loss of both GLI2 and GLI3 was able to phenocopy the ciliopathic midfacial appearance. Our findings suggest that ciliopathic facial phenotypes are generated via loss of both GLI3R and GLI2R and that this pathology occurs via a de-repression mechanism. Furthermore, these studies suggest a novel role for GLI2R in craniofacial development. Primary cilia are ubiquitous organelles that serve to transduce molecular signals within a cell. Loss of functional primary cilia results in a disease class called ciliopathies. Ciliopathies have a broad range of phenotypes; however, severe facial anomalies are commonly associated with this disease class. The facial midline is particularly sensitive to loss of primary cilia, frequently undergoing a significant widening. This phenotype is similar to that which occurs when there are gain-of-function defects in the Sonic Hedgehog pathway. This manuscript addresses the molecular basis for midfacial widening in ciliopathies. Importantly, we determine mechanisms to both rescue and phenocopy the ciliopathic midfacial phenotype. In sum, this work provides novel insight into the molecular mechanisms of midfacial patterning and the extent to which loss of cilia impact that process.
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Affiliation(s)
- Ching-Fang Chang
- Division of Plastic Surgery, Department of Surgery and Division of Developmental Biology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati
| | - Ya-Ting Chang
- Division of Plastic Surgery, Department of Surgery and Division of Developmental Biology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati
| | - Grethel Millington
- Division of Plastic Surgery, Department of Surgery and Division of Developmental Biology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati
| | - Samantha A. Brugmann
- Division of Plastic Surgery, Department of Surgery and Division of Developmental Biology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati
- * E-mail:
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103
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Control of Hedgehog Signalling by the Cilia-Regulated Proteasome. J Dev Biol 2016; 4:jdb4030027. [PMID: 29615591 PMCID: PMC5831775 DOI: 10.3390/jdb4030027] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 08/25/2016] [Accepted: 08/29/2016] [Indexed: 12/31/2022] Open
Abstract
The Hedgehog signalling pathway is evolutionarily highly conserved and essential for embryonic development of invertebrates and vertebrates. Consequently, impaired Hedgehog signalling results in very severe human diseases, ranging from holoprosencephaly to Pallister-Hall syndrome. Due to this great importance for human health, the focus of numerous research groups is placed on the investigation of the detailed mechanisms underlying Hedgehog signalling. Today, it is known that tiny cell protrusions, known as primary cilia, are necessary to mediate Hedgehog signalling in vertebrates. Although the Hedgehog pathway is one of the best studied signalling pathways, many questions remain. One of these questions is: How do primary cilia control Hedgehog signalling in vertebrates? Recently, it was shown that primary cilia regulate a special kind of proteasome which is essential for proper Hedgehog signalling. This review article will cover this novel cilia-proteasome association in embryonic Hedgehog signalling and discuss the possibilities provided by future investigations on this topic.
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104
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Zhang Y, Alvarez-Bolado G. Differential developmental strategies by Sonic hedgehog in thalamus and hypothalamus. J Chem Neuroanat 2016; 75:20-7. [DOI: 10.1016/j.jchemneu.2015.11.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 11/25/2015] [Indexed: 12/11/2022]
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105
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Habib JG, O'Shaughnessy JA. The hedgehog pathway in triple-negative breast cancer. Cancer Med 2016; 5:2989-3006. [PMID: 27539549 PMCID: PMC5083752 DOI: 10.1002/cam4.833] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 05/26/2016] [Accepted: 06/30/2016] [Indexed: 12/11/2022] Open
Abstract
Treatment of triple‐negative breast cancer (TNBC) remains challenging due to the underlying heterogeneity of this disease coupled with the lack of predictive biomarkers and effective targeted therapies. Intratumoral heterogeneity, particularly enrichment for breast cancer stem cell‐like subpopulations, has emerged as a leading hypothesis for systemic therapy resistance and clinically aggressive course of poor prognosis TNBC. A growing body of literature supports the role of the stem cell renewal Hedgehog (Hh) pathway in breast cancer. Emerging preclinical data also implicate Hh signaling in TNBC pathogenesis. Herein, we review the evidence for a pathophysiologic role of Hh signaling in TNBC and explore mechanisms of crosstalk between the Hh pathway and other key signaling networks as well as their potential implications for Hh‐targeted interventions in TNBC.
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Affiliation(s)
- Joyce G Habib
- Baylor Charles A. Sammons Cancer Center, Dallas, Texas
| | - Joyce A O'Shaughnessy
- Baylor Charles A. Sammons Cancer Center, Dallas, Texas.
- Texas Oncology, Dallas, Texas.
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106
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Zhu L, Ni C, Dong B, Zhang Y, Shi Y, Niu H, Li C. A novel hedgehog inhibitor iG2 suppresses tumorigenesis by impairing self-renewal in human bladder cancer. Cancer Med 2016; 5:2579-86. [PMID: 27465044 PMCID: PMC5055183 DOI: 10.1002/cam4.802] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 05/08/2016] [Accepted: 05/22/2016] [Indexed: 01/07/2023] Open
Abstract
Tumor recurrence is still a major challenge for clinical treatment of bladder cancer. Cumulative evidences indicate cancer stem cells (CSCs) contribute to drug resistance and leave a putative source for disease relapse. Identifying novel agents targeting CSCs may represent a new paradigm in the therapy of bladder cancer. Here, we separated a novel hedgehog (Hh) inhibitor, iG2, from streptomyces roseofulvus, which dramatically blocked the activation of Gli2 in bladder cancer cells. The iG2 strongly repressed the growth of cancer cells rather than the peri‐tumor stroma cells. Attenuated proliferation and enhanced apoptosis of tumor cells were observed upon iG2 stimulation. Furthermore, iG2 reduced the self‐renewal ability of bladder CSCs as well as the tumor formation. Collectively, iG2 is potentially used as a novel therapeutic agent for bladder cancer by targeting self‐renewal through inhibiting Hh pathway.
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Affiliation(s)
- Lihong Zhu
- Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Chen Ni
- Medical Research Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Baijun Dong
- Department of Urology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Yong Zhang
- Department of Urology, the Affiliated Hospital of Qingdao University, Qingdao, 266003, China
| | - Yuefeng Shi
- Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Haitao Niu
- Department of Urology, the Affiliated Hospital of Qingdao University, Qingdao, 266003, China.
| | - Chong Li
- Laboratory Animal Center, CAS Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
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107
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Ramsbottom SA, Pownall ME, Roelink H, Conway SJ. Regulation of Hedgehog Signalling Inside and Outside the Cell. J Dev Biol 2016; 4:23. [PMID: 27547735 PMCID: PMC4990124 DOI: 10.3390/jdb4030023] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
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.
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Affiliation(s)
- Simon A. Ramsbottom
- Institute of Genetic Medicine, International Centre for Life, Newcastle University, NE1 3BZ Newcastle upon Tyne, UK
- Correspondence: ; Tel.: +44-(0)191-241-8612
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108
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Barbarulo A, Lau CI, Mengrelis K, Ross S, Solanki A, Saldaña JI, Crompton T, Roelink H, Conway SJ. Hedgehog Signalling in the Embryonic Mouse Thymus. J Dev Biol 2016; 4:22. [PMID: 27504268 PMCID: PMC4975939 DOI: 10.3390/jdb4030022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 07/14/2016] [Indexed: 01/05/2023] Open
Abstract
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.
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Affiliation(s)
| | | | | | | | | | | | - Tessa Crompton
- Immunobiology Section, UCL Institute of Child Health, London WC1N 1EH, UK; (A.B.); (C.-I.L.); (K.M.); (S.R.); (A.S.); (J.I.S.)
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109
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Fleet A, Lee JPY, Tamachi A, Javeed I, Hamel PA. Activities of the Cytoplasmic Domains of Patched-1 Modulate but Are Not Essential for the Regulation of Canonical Hedgehog Signaling. J Biol Chem 2016; 291:17557-68. [PMID: 27325696 DOI: 10.1074/jbc.m116.731745] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Indexed: 12/15/2022] Open
Abstract
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.
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Affiliation(s)
- Andrew Fleet
- From the Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Jennifer P Y Lee
- From the Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Aaliya Tamachi
- From the Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Imaan Javeed
- From the Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Paul A Hamel
- From the Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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110
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Gerhardt C, Leu T, Lier JM, Rüther U. The cilia-regulated proteasome and its role in the development of ciliopathies and cancer. Cilia 2016; 5:14. [PMID: 27293550 PMCID: PMC4901515 DOI: 10.1186/s13630-016-0035-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 02/29/2016] [Indexed: 12/21/2022] Open
Abstract
The primary cilium is an essential structure for the mediation of numerous signaling pathways involved in the coordination and regulation of cellular processes essential for the development and maintenance of health. Consequently, ciliary dysfunction results in severe human diseases called ciliopathies. Since many of the cilia-mediated signaling pathways are oncogenic pathways, cilia are linked to cancer. Recent studies demonstrate the existence of a cilia-regulated proteasome and that this proteasome is involved in cancer development via the progression of oncogenic, cilia-mediated signaling. This review article investigates the association between primary cilia and cancer with particular emphasis on the role of the cilia-regulated proteasome.
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Affiliation(s)
- Christoph Gerhardt
- Institute for Animal Developmental and Molecular Biology, Heinrich-Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Tristan Leu
- Institute for Animal Developmental and Molecular Biology, Heinrich-Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Johanna Maria Lier
- Institute for Animal Developmental and Molecular Biology, Heinrich-Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Ulrich Rüther
- Institute for Animal Developmental and Molecular Biology, Heinrich-Heine University Düsseldorf, 40225 Düsseldorf, Germany
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111
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Moura RS, Silva-Gonçalves C, Vaz-Cunha P, Correia-Pinto J. Expression analysis of Shh signaling members in early stages of chick lung development. Histochem Cell Biol 2016; 146:457-66. [PMID: 27221780 DOI: 10.1007/s00418-016-1448-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/09/2016] [Indexed: 12/16/2022]
Abstract
Lung organogenesis is guided by epithelial-mesenchymal interactions that coordinate cellular events responsible for the formation of the respiratory system. Several signaling pathways have been implicated in this process; among them, sonic hedgehog (Shh) signaling has emerged as a crucial regulator of branching morphogenesis in the mammalian lung. Canonical Shh signaling requires the presence of patched (Ptch) and smoothened (Smo) transmembrane receptors in order to induce the activation of glioblastoma (Gli) zinc finger transcription factors that are the true effectors of the pathway. Signal transduction is finely regulated by Ptch1, Gli, and Hhip (hedgehog-interacting protein). The present work characterizes, for the first time, the expression pattern of shh, ptch1, smo, gli1, and hhip in early stages of the embryonic chick lung. In situ hybridization studies revealed that these genes are expressed in the same cellular compartments as their mammalian counterparts, although their proximo-distal distribution is slightly changed. Moreover, the molecular interactions between fibroblast growth factor (FGF) and Shh signaling pathway were assessed, in vitro, by grafting beads soaked in SU5402 (an FGF receptor inhibitor). In the chick lung, Shh signaling seems to have some features that are species specific since shh is not a downstream target of FGF signaling. Nonetheless and despite the observed differences, these findings suggest a role for Shh signaling in the epithelial-mesenchymal interactions that control chick lung morphogenesis.
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Affiliation(s)
- Rute Silva Moura
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4710-057, Braga, Portugal.
- ICVS/3B's - PT Government Associate Laboratory, 4710-057, Braga/Guimarães, Portugal.
- Biology Department, School of Sciences, University of Minho, 4710-057, Braga, Portugal.
| | - Carla Silva-Gonçalves
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4710-057, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, 4710-057, Braga/Guimarães, Portugal
| | - Patrícia Vaz-Cunha
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4710-057, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, 4710-057, Braga/Guimarães, Portugal
| | - Jorge Correia-Pinto
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4710-057, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, 4710-057, Braga/Guimarães, Portugal
- Department of Pediatric Surgery, Hospital de Braga, 4710-243, Braga, Portugal
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112
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Pyczek J, Buslei R, Schult D, Hölsken A, Buchfelder M, Heß I, Hahn H, Uhmann A. Hedgehog signaling activation induces stem cell proliferation and hormone release in the adult pituitary gland. Sci Rep 2016; 6:24928. [PMID: 27109116 PMCID: PMC4842994 DOI: 10.1038/srep24928] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 04/07/2016] [Indexed: 11/09/2022] Open
Abstract
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.
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Affiliation(s)
- Joanna Pyczek
- Institute of Human Genetics, Tumor Genetics Group, University of Göttingen, Germany
| | - Rolf Buslei
- Institute of Neuropathology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Germany
| | - David Schult
- Institute of Neuropathology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Germany
| | - Annett Hölsken
- Institute of Neuropathology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Germany
| | - Michael Buchfelder
- Department of Neurosurgery, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Germany
| | - Ina Heß
- Institute of Human Genetics, Tumor Genetics Group, University of Göttingen, Germany
| | - Heidi Hahn
- Institute of Human Genetics, Tumor Genetics Group, University of Göttingen, Germany
| | - Anja Uhmann
- Institute of Human Genetics, Tumor Genetics Group, University of Göttingen, Germany
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113
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Zhang J, Tian XJ, Xing J. Signal Transduction Pathways of EMT Induced by TGF-β, SHH, and WNT and Their Crosstalks. J Clin Med 2016; 5:jcm5040041. [PMID: 27043642 PMCID: PMC4850464 DOI: 10.3390/jcm5040041] [Citation(s) in RCA: 232] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 01/31/2016] [Accepted: 03/21/2016] [Indexed: 12/12/2022] Open
Abstract
Epithelial-to-mesenchymal transition (EMT) is a key step in development, wound healing, and cancer development. It involves cooperation of signaling pathways, such as transformation growth factor-β (TGF-β), Sonic Hedgehog (SHH), and WNT pathways. These signaling pathways crosstalk to each other and converge to key transcription factors (e.g., SNAIL1) to initialize and maintain the process of EMT. The functional roles of multi-signaling pathway crosstalks in EMT are sophisticated and, thus, remain to be explored. In this review, we focused on three major signal transduction pathways that promote or regulate EMT in carcinoma. We discussed the network structures, and provided a brief overview of the current therapy strategies and drug development targeted to these three signal transduction pathways. Finally, we highlighted systems biology approaches that can accelerate the process of deconstructing complex networks and drug discovery.
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Affiliation(s)
- Jingyu Zhang
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| | - Xiao-Jun Tian
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| | - Jianhua Xing
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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114
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Wang MT, Holderfield M, Galeas J, Delrosario R, To MD, Balmain A, McCormick F. K-Ras Promotes Tumorigenicity through Suppression of Non-canonical Wnt Signaling. Cell 2016; 163:1237-1251. [PMID: 26590425 DOI: 10.1016/j.cell.2015.10.041] [Citation(s) in RCA: 126] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 10/01/2015] [Accepted: 10/13/2015] [Indexed: 12/30/2022]
Abstract
K-Ras and H-Ras share identical effectors and have similar properties; however, the high degree of tumor-type specificity associated with K-Ras and H-Ras mutations suggests that they have unique roles in oncogenesis. Here, we report that oncogenic K-Ras, but not H-Ras, suppresses non-canonical Wnt/Ca(2+) signaling, an effect that contributes strongly to its tumorigenic properties. K-Ras does this by binding to calmodulin and so reducing CaMKii activity and expression of Fzd8. Restoring Fzd8 in K-Ras mutant pancreatic cells suppresses malignancy, whereas depletion of Fzd8 in H-Ras(V12)-transformed cells enhances their tumor initiating capacity. Interrupting K-Ras-calmodulin binding using genetic means or by treatment with an orally active protein kinase C (PKC)-activator, prostratin, represses tumorigenesis in K-Ras mutant pancreatic cancer cells. These findings provide an alternative way to selectively target this "undruggable" protein.
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Affiliation(s)
- Man-Tzu Wang
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, 1450 3(rd) Street, San Francisco, CA 94158, USA
| | - Matthew Holderfield
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, 1450 3(rd) Street, San Francisco, CA 94158, USA
| | - Jacqueline Galeas
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, 1450 3(rd) Street, San Francisco, CA 94158, USA
| | - Reyno Delrosario
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, 1450 3(rd) Street, San Francisco, CA 94158, USA
| | - Minh D To
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, 1450 3(rd) Street, San Francisco, CA 94158, USA
| | - Allan Balmain
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, 1450 3(rd) Street, San Francisco, CA 94158, USA
| | - Frank McCormick
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, 1450 3(rd) Street, San Francisco, CA 94158, USA.
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Gurdziel K, Vogt KR, Schneider G, Richards N, Gumucio DL. Computational prediction and experimental validation of novel Hedgehog-responsive enhancers linked to genes of the Hedgehog pathway. BMC DEVELOPMENTAL BIOLOGY 2016; 16:4. [PMID: 26912062 PMCID: PMC4765071 DOI: 10.1186/s12861-016-0106-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 02/16/2016] [Indexed: 12/14/2022]
Abstract
BACKGROUND The Hedgehog (Hh) signaling pathway, acting through three homologous transcription factors (GLI1, GLI2, GLI3) in vertebrates, plays multiple roles in embryonic organ development and adult tissue homeostasis. At the level of the genome, GLI factors bind to specific motifs in enhancers, some of which are hundreds of kilobases removed from the gene promoter. These enhancers integrate the Hh signal in a context-specific manner to control the spatiotemporal pattern of target gene expression. Importantly, a number of genes that encode Hh pathway molecules are themselves targets of Hh signaling, allowing pathway regulation by an intricate balance of feed-back activation and inhibition. However, surprisingly few of the critical enhancer elements that control these pathway target genes have been identified despite the fact that such elements are central determinants of Hh signaling activity. Recently, ChIP studies have been carried out in multiple tissue contexts using mouse models carrying FLAG-tagged GLI proteins (GLI(FLAG)). Using these datasets, we tested whether a meta-analysis of GLI binding sites, coupled with a machine learning approach, could reveal genomic features that could be used to empirically identify Hh-regulated enhancers linked to loci of the Hh signaling pathway. RESULTS A meta-analysis of four existing GLI(FLAG) datasets revealed a library of GLI binding motifs that was substantially more restricted than the potential sites predicted by previous in vitro binding studies. A machine learning method (kmer-SVM) was then applied to these datasets and enriched k-mers were identified that, when applied to the mouse genome, predicted as many as 37,000 potential Hh enhancers. For functional analysis, we selected nine regions which were annotated to putative Hh pathway molecules and found that seven exhibited GLI-dependent activity, indicating that they are directly regulated by Hh signaling (78% success rate). CONCLUSIONS The results suggest that Hh enhancer regions share common sequence features. The kmer-SVM machine learning approach identifies those features and can successfully predict functional Hh regulatory regions in genomic DNA surrounding Hh pathway molecules and likely, other Hh targets. Additionally, the library of enriched GLI binding motifs that we have identified may allow improved identification of functional GLI binding sites.
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Affiliation(s)
- Katherine Gurdziel
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Kyle R Vogt
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Gary Schneider
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Neil Richards
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Deborah L Gumucio
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
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Rimkus TK, Carpenter RL, Qasem S, Chan M, Lo HW. Targeting the Sonic Hedgehog Signaling Pathway: Review of Smoothened and GLI Inhibitors. Cancers (Basel) 2016; 8:cancers8020022. [PMID: 26891329 PMCID: PMC4773745 DOI: 10.3390/cancers8020022] [Citation(s) in RCA: 409] [Impact Index Per Article: 51.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 01/25/2016] [Accepted: 02/05/2016] [Indexed: 12/25/2022] Open
Abstract
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.
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Affiliation(s)
- Tadas K Rimkus
- Department of Cancer Biology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
| | - Richard L Carpenter
- Department of Cancer Biology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
| | - Shadi Qasem
- Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
- Comprehensive Cancer Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
| | - Michael Chan
- Comprehensive Cancer Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
- Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
| | - Hui-Wen Lo
- Department of Cancer Biology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
- Comprehensive Cancer Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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Ringuette R, Atkins M, Lagali PS, Bassett EA, Campbell C, Mazerolle C, Mears AJ, Picketts DJ, Wallace VA. A Notch-Gli2 axis sustains Hedgehog responsiveness of neural progenitors and Müller glia. Dev Biol 2016; 411:85-100. [PMID: 26795056 DOI: 10.1016/j.ydbio.2016.01.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 01/05/2016] [Accepted: 01/11/2016] [Indexed: 11/18/2022]
Abstract
Neurogenesis is regulated by the dynamic and coordinated activity of several extracellular signalling pathways, but the basis for crosstalk between these pathways remains poorly understood. Here we investigated regulatory interactions between two pathways that are each required for neural progenitor cell maintenance in the postnatal retina; Hedgehog (Hh) and Notch signalling. Both pathways are activated in progenitor cells in the postnatal retina based on the co-expression of fluorescent pathway reporter transgenes at the single cell level. Disrupting Notch signalling, genetically or pharmacologically, induces a rapid downregulation of all three Gli proteins and inhibits Hh-induced proliferation. Ectopic Notch activation, while not sufficient to promote Hh signalling or proliferation, increases Gli2 protein. We show that Notch regulation of Gli2 in Müller glia renders these cells competent to proliferate in response to Hh. These data suggest that Notch signalling converges on Gli2 to prime postnatal retinal progenitor cells and Müller glia to proliferate in response to Hh.
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Affiliation(s)
- Randy Ringuette
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
| | - Michael Atkins
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6
| | - Pamela S Lagali
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6
| | - Erin A Bassett
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6
| | - Charles Campbell
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
| | - Chantal Mazerolle
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6
| | - Alan J Mears
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6
| | - David J Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6; Department of Biochemistry, Microbiology and Immunology, Department of Ophthalmology, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
| | - Valerie A Wallace
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada K1H 8L6; Department of Biochemistry, Microbiology and Immunology, Department of Ophthalmology, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5; Vision Research Division, Krembil Research Institute, University Health Network and Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada.
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118
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Li Q, Lex RK, Chung H, Giovanetti SM, Ji Z, Ji H, Person MD, Kim J, Vokes SA. The Pluripotency Factor NANOG Binds to GLI Proteins and Represses Hedgehog-mediated Transcription. J Biol Chem 2016; 291:7171-82. [PMID: 26797124 DOI: 10.1074/jbc.m116.714857] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Indexed: 01/20/2023] Open
Abstract
The Hedgehog (HH) signaling pathway is essential for the maintenance and response of several types of stem cells. To study the transcriptional response of stem cells to HH signaling, we searched for proteins binding to GLI proteins, the transcriptional effectors of the HH pathway in mouse embryonic stem (ES) cells. We found that both GLI3 and GLI1 bind to the pluripotency factor NANOG. The ectopic expression of NANOG inhibits GLI1-mediated transcriptional responses in a dose-dependent fashion. In differentiating ES cells, the presence of NANOG reduces the transcriptional response of cells to HH. Finally, we found thatGli1andNanogare co-expressed in ES cells at high levels. We propose that NANOG acts as a negative feedback component that provides stem cell-specific regulation of the HH pathway.
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Affiliation(s)
- Qiang Li
- From the Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, and
| | - Rachel K Lex
- From the Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, and
| | - HaeWon Chung
- From the Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, and
| | - Simone M Giovanetti
- From the Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, and
| | - Zhicheng Ji
- Department of Biostatistics, The Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205
| | - Hongkai Ji
- Department of Biostatistics, The Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205
| | - Maria D Person
- Institute for Cellular and Molecular Biology, and Proteomics Facility, The University of Texas, Austin, Texas 78712 and
| | - Jonghwan Kim
- From the Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, and
| | - Steven A Vokes
- From the Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, and
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119
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Vlčková K, Ondrušová L, Vachtenheim J, Réda J, Dundr P, Zadinová M, Žáková P, Poučková P. Survivin, a novel target of the Hedgehog/GLI signaling pathway in human tumor cells. Cell Death Dis 2016; 7:e2048. [PMID: 26775700 PMCID: PMC4816174 DOI: 10.1038/cddis.2015.389] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/30/2015] [Accepted: 12/01/2015] [Indexed: 12/12/2022]
Abstract
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.
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Affiliation(s)
- K Vlčková
- Laboratory of Transcription and Cell Signaling, Institute of Medical Biochemistry and Laboratory Diagnostics, Charles University in Prague, 1st Faculty of Medicine, Prague, Czech Republic
| | - L Ondrušová
- Laboratory of Transcription and Cell Signaling, Institute of Medical Biochemistry and Laboratory Diagnostics, Charles University in Prague, 1st Faculty of Medicine, Prague, Czech Republic
| | - J Vachtenheim
- Laboratory of Transcription and Cell Signaling, Institute of Medical Biochemistry and Laboratory Diagnostics, Charles University in Prague, 1st Faculty of Medicine, Prague, Czech Republic
| | - J Réda
- Laboratory of Transcription and Cell Signaling, Institute of Medical Biochemistry and Laboratory Diagnostics, Charles University in Prague, 1st Faculty of Medicine, Prague, Czech Republic
| | - P Dundr
- Institute of Pathology, Charles University in Prague, 1st Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic
| | - M Zadinová
- Institute of Biophysics and Informatics, Charles University in Prague, 1st Faculty of Medicine, Prague, Czech Republic
| | - P Žáková
- Laboratory of Transcription and Cell Signaling, Institute of Medical Biochemistry and Laboratory Diagnostics, Charles University in Prague, 1st Faculty of Medicine, Prague, Czech Republic
| | - P Poučková
- Institute of Biophysics and Informatics, Charles University in Prague, 1st Faculty of Medicine, Prague, Czech Republic
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120
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The ATM- and ATR-related SCD domain is over-represented in proteins involved in nervous system development. Sci Rep 2016; 6:19050. [PMID: 26743489 PMCID: PMC4705472 DOI: 10.1038/srep19050] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 12/02/2015] [Indexed: 12/16/2022] Open
Abstract
ATM and ATR are cellular kinases with a well-characterized role in the DNA-damage response. Although the complete set of ATM/ATR targets is unknown, they often contain clusters of S/TQ motifs that constitute an SCD domain. In this study, we identified putative ATM/ATR targets that have a conserved SCD domain across vertebrates. Using this approach, we have identified novel putative ATM/ATR targets in pathways known to be under direct control of these kinases. Our analysis has also unveiled significant enrichment of SCD-containing proteins in cellular pathways, such as vesicle trafficking and actin cytoskeleton, where a regulating role for ATM/ATR is either unknown or poorly understood, hinting at a much broader and overarching role for these kinases in the cell. Of particular note is the overrepresentation of conserved SCD-containing proteins involved in pathways related to neural development. This finding suggests that ATM/ATR could be directly involved in controlling this process, which may be linked to the adverse neurological effects observed in patients with mutations in ATM.
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121
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Jones GE, Robertson L, Maniyar A, Shammas C, Phelan MM, Vasudevan PC, Tanteles GA. Microform holoprosencephaly with bilateral congenital elbow dislocation; increasing the phenotypic spectrum of Steinfeld syndrome. Am J Med Genet A 2016; 170:754-9. [PMID: 26728615 DOI: 10.1002/ajmg.a.37511] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 11/29/2015] [Indexed: 11/12/2022]
Abstract
Steinfeld syndrome (MIM #184705) was first reported in 1982. It is characterised by holoprosencephaly and limb defects, however other anomalies may also be present. Following the initial description, three further cases have been reported in the literature. We report on a 23-year-old girl, with features of microform holoprosencephaly and bilateral congenital elbow dislocation in association with hypoplastic radial heads. She was identified to have a variant in the CDON gene inherited from her father who had ocular hypotelorism, but no other clinical features. We discuss the clinical features of Steinfeld syndrome, and broaden the phenotypic spectrum of this condition. Structural analysis suggests that this variant could lead to destabilisation of binding of CDON with hedgehog proteins. Further work needs to be done to confirm whether mutations in the CDON gene are the cause of Steinfeld syndrome.
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Affiliation(s)
- Gabriela E Jones
- Department of Clinical Genetics, University Hospitals Leicester NHS Trust, Leicester, United Kingdom
| | - Lisa Robertson
- North of Scotland Clinical Genetics Service, Aberdeen, United Kingdom
| | - Amit Maniyar
- Department of Radiology, University Hospitals Leicester NHS Trust, Leicester, United Kingdom
| | - Christos Shammas
- Department of Molecular Genetics, Function and Therapy, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Marie M Phelan
- NMR Centre for Structural Biology, Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Pradeep C Vasudevan
- Department of Clinical Genetics, University Hospitals Leicester NHS Trust, Leicester, United Kingdom
| | - George A Tanteles
- Clinical Genetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
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122
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Trnski D, Sabol M, Gojević A, Martinić M, Ozretić P, Musani V, Ramić S, Levanat S. GSK3β and Gli3 play a role in activation of Hedgehog-Gli pathway in human colon cancer - Targeting GSK3β downregulates the signaling pathway and reduces cell proliferation. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1852:2574-84. [PMID: 26385428 DOI: 10.1016/j.bbadis.2015.09.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 09/04/2015] [Accepted: 09/12/2015] [Indexed: 02/08/2023]
Abstract
The role of Hedgehog-Gli (Hh-Gli) signaling in colon cancer tumorigenesis has not yet been completely elucidated. Here we provide strong evidence of Hh-Gli signaling involvement in survival of colon cancer cells, with the main trigger of activation being deregulated GSK3β. Our clinical data reveals high expression levels of GSK3β and Gli3 in human colon cancer tissue samples, with positive correlation between GSK3β expression and DUKES' stage. Further experiments on colon cancer cell lines have shown that a deregulated GSK3β upregulates Hh-Gli signaling and positively affects colon cancer cell survival. We show that inhibition of GSK3β with lithium chloride enhances Gli3 processing into its repressor form, consequently downregulating Hh-Gli signaling, reducing cell proliferation and inducing cell death. Analysis of the molecular mechanisms revealed that lithium chloride enhances Gli3-SuFu-GSK3β complex formation leading to more efficient Gli3 cleavage and Hh-Gli signaling downregulation. This work proposes that activation of the Hh-Gli signaling pathway in colon cancer cells occurs non-canonically via deregulated GSK3β. Gli3 seems to be the main pathway effector, highlighting the activator potential of this transcription factor, which is highly dependent on GSK3β function and fine tuning of the Gli3-SuFu-GSK3β platform.
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Affiliation(s)
- Diana Trnski
- Department of Molecular Medicine, Rudjer Boskovic Institute, Bijenička 54, Zagreb, Croatia.
| | - Maja Sabol
- Department of Molecular Medicine, Rudjer Boskovic Institute, Bijenička 54, Zagreb, Croatia.
| | - Ante Gojević
- Department of Surgery, University Hospital Center Zagreb, Kišpatićeva 12, Zagreb, Croatia.
| | - Marina Martinić
- Department of Molecular Medicine, Rudjer Boskovic Institute, Bijenička 54, Zagreb, Croatia.
| | - Petar Ozretić
- Department of Molecular Medicine, Rudjer Boskovic Institute, Bijenička 54, Zagreb, Croatia.
| | - Vesna Musani
- Department of Molecular Medicine, Rudjer Boskovic Institute, Bijenička 54, Zagreb, Croatia.
| | - Snježana Ramić
- Department of Pathology, University Hospital for Tumors, Sestre milosrdnice University Hospital Center, Ilica 197, Zagreb, Croatia.
| | - Sonja Levanat
- Department of Molecular Medicine, Rudjer Boskovic Institute, Bijenička 54, Zagreb, Croatia.
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Feitelson MA, Arzumanyan A, Kulathinal RJ, Blain SW, Holcombe RF, Mahajna J, Marino M, Martinez-Chantar ML, Nawroth R, Sanchez-Garcia I, Sharma D, Saxena NK, Singh N, Vlachostergios PJ, Guo S, Honoki K, Fujii H, Georgakilas AG, Bilsland A, Amedei A, Niccolai E, Amin A, Ashraf SS, Boosani CS, Guha G, Ciriolo MR, Aquilano K, Chen S, Mohammed SI, Azmi AS, Bhakta D, Halicka D, Keith WN, Nowsheen S. Sustained proliferation in cancer: Mechanisms and novel therapeutic targets. Semin Cancer Biol 2015; 35 Suppl:S25-S54. [PMID: 25892662 PMCID: PMC4898971 DOI: 10.1016/j.semcancer.2015.02.006] [Citation(s) in RCA: 406] [Impact Index Per Article: 45.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 02/20/2015] [Accepted: 02/23/2015] [Indexed: 02/08/2023]
Abstract
Proliferation is an important part of cancer development and progression. This is manifest by altered expression and/or activity of cell cycle related proteins. Constitutive activation of many signal transduction pathways also stimulates cell growth. Early steps in tumor development are associated with a fibrogenic response and the development of a hypoxic environment which favors the survival and proliferation of cancer stem cells. Part of the survival strategy of cancer stem cells may manifested by alterations in cell metabolism. Once tumors appear, growth and metastasis may be supported by overproduction of appropriate hormones (in hormonally dependent cancers), by promoting angiogenesis, by undergoing epithelial to mesenchymal transition, by triggering autophagy, and by taking cues from surrounding stromal cells. A number of natural compounds (e.g., curcumin, resveratrol, indole-3-carbinol, brassinin, sulforaphane, epigallocatechin-3-gallate, genistein, ellagitannins, lycopene and quercetin) have been found to inhibit one or more pathways that contribute to proliferation (e.g., hypoxia inducible factor 1, nuclear factor kappa B, phosphoinositide 3 kinase/Akt, insulin-like growth factor receptor 1, Wnt, cell cycle associated proteins, as well as androgen and estrogen receptor signaling). These data, in combination with bioinformatics analyses, will be very important for identifying signaling pathways and molecular targets that may provide early diagnostic markers and/or critical targets for the development of new drugs or drug combinations that block tumor formation and progression.
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Affiliation(s)
- Mark A Feitelson
- Department of Biology, Temple University, Philadelphia, PA, United States.
| | - Alla Arzumanyan
- Department of Biology, Temple University, Philadelphia, PA, United States
| | - Rob J Kulathinal
- Department of Biology, Temple University, Philadelphia, PA, United States
| | - Stacy W Blain
- Department of Pediatrics, State University of New York, Downstate Medical Center, Brooklyn, NY, United States
| | - Randall F Holcombe
- Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY, United States
| | - Jamal Mahajna
- MIGAL-Galilee Technology Center, Cancer Drug Discovery Program, Kiryat Shmona, Israel
| | - Maria Marino
- Department of Science, University Roma Tre, V.le G. Marconi, 446, 00146 Rome, Italy
| | - Maria L Martinez-Chantar
- Metabolomic Unit, CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Technology Park of Bizkaia, Bizkaia, Spain
| | - Roman Nawroth
- Department of Urology, Klinikum rechts der Isar der Technischen Universität München, Munich, Germany
| | - Isidro Sanchez-Garcia
- Experimental Therapeutics and Translational Oncology Program, Instituto de Biología Molecular y Celular del Cáncer, CSIC/Universidad de Salamanca, Salamanca, Spain
| | - Dipali Sharma
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Neeraj K Saxena
- Department of Oncology, Johns Hopkins University School of Medicine and the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD, United States
| | - Neetu Singh
- Tissue and Cell Culture Unit, CSIR-Central Drug Research Institute, Council of Scientific & Industrial Research, Lucknow, India
| | | | - Shanchun Guo
- Department of Microbiology, Biochemistry & Immunology, Morehouse School of Medicine, Atlanta, GA, United States
| | - Kanya Honoki
- Department of Orthopedic Surgery, Nara Medical University, Kashihara 634-8521, Japan
| | - Hiromasa Fujii
- Department of Orthopedic Surgery, Nara Medical University, Kashihara 634-8521, Japan
| | - Alexandros G Georgakilas
- Physics Department, School of Applied Mathematical and Physical Sciences, National Technical University of Athens, Zografou 15780, Athens, Greece
| | - Alan Bilsland
- Institute of Cancer Sciences, University of Glasgow, UK
| | - Amedeo Amedei
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Elena Niccolai
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Amr Amin
- Department of Biology, College of Science, UAE University, Al-Ain, United Arab Emirates
| | - S Salman Ashraf
- Department of Chemistry, College of Science, UAE University, Al-Ain, United Arab Emirates
| | - Chandra S Boosani
- Department of BioMedical Sciences, Creighton University, Omaha, NE, United States
| | - Gunjan Guha
- School of Chemical and Bio Technology, SASTRA University, Thanjavur, India
| | - Maria Rosa Ciriolo
- Department of Biology, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Katia Aquilano
- Department of Biology, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Sophie Chen
- Department of Research and Development, Ovarian and Prostate Cancer Research Trust Laboratory, Guildford, Surrey GU2 7YG, United Kingdom
| | - Sulma I Mohammed
- Department of Comparative Pathobiology, Purdue University Center for Cancer Research, West Lafayette, IN, United States
| | - Asfar S Azmi
- Department of Pathology, Karmonas Cancer Institute, Wayne State University School of Medicine, Detroit, MI, United States
| | - Dipita Bhakta
- School of Chemical and Bio Technology, SASTRA University, Thanjavur, India
| | - Dorota Halicka
- Brander Cancer Research Institute, Department of Pathology, New York Medical College, Valhalla, NY, United States
| | - W Nicol Keith
- Institute of Cancer Sciences, University of Glasgow, UK
| | - Somaira Nowsheen
- Mayo Graduate School, Mayo Medical School, Mayo Clinic Medical Scientist Training Program, Rochester, MN, United States
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Overcoming Multidrug Resistance in Cancer Stem Cells. BIOMED RESEARCH INTERNATIONAL 2015; 2015:635745. [PMID: 26649310 PMCID: PMC4663294 DOI: 10.1155/2015/635745] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Revised: 10/09/2015] [Accepted: 10/19/2015] [Indexed: 01/03/2023]
Abstract
The principle mechanism of protection of stem cells is through the expression of ATP-binding cassette (ABC) transporters. These transporters serve as the guardians of the stem cell population in the body. Unfortunately these very same ABC efflux pumps afford protection to cancer stem cells in tumors, shielding them from the adverse effects of chemotherapy. A number of strategies to circumvent the function of these transporters in cancer stem cells are currently under investigation. These strategies include the development of competitive and allosteric modulators, nanoparticle mediated delivery of inhibitors, targeted transcriptional regulation of ABC transporters, miRNA mediated inhibition, and targeting of signaling pathways that modulate ABC transporters. The role of ABC transporters in cancer stem cells will be explored in this paper and strategies aimed at overcoming drug resistance caused by these particular transporters will also be discussed.
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125
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Sadam H, Liivas U, Kazantseva A, Pruunsild P, Kazantseva J, Timmusk T, Neuman T, Palm K. GLI2 cell-specific activity is controlled at the level of transcription and RNA processing: Consequences to cancer metastasis. Biochim Biophys Acta Mol Basis Dis 2015; 1862:46-55. [PMID: 26459048 DOI: 10.1016/j.bbadis.2015.10.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 10/08/2015] [Accepted: 10/09/2015] [Indexed: 01/14/2023]
Abstract
High activity of GLI family zinc finger protein 2 (GLI2) promotes tumor progression. Removal of the repressor domain at the N terminus (GLI2∆N) by recombinant methods converts GLI2 into a powerful transcriptional activator. However, molecular mechanisms leading to the formation of GLI2∆N activator proteins have not been established. Herein we report for the first time that the functional activities of GLI2 are parted into different protein isoforms by alternative promoter usage, selection of alternative splicing, transcription initiation and termination sites. Functional studies using melanoma cells revealed that transcriptional regulation of GLI2 is TGFbeta-dependent and supports the predominant production of GLI2∆N and C-terminally truncated GLI2 (GLI2∆C) isoforms in cells with high migratory and invasive phenotype. Taken together, these results highlight the role of transcription and RNA processing as major processes in the regulation of GLI2 activity with severe impacts in cancer development.
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Affiliation(s)
- Helle Sadam
- Protobios Llc, Mäealuse 4, Tallinn 12618, Estonia; Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
| | - Urmas Liivas
- Protobios Llc, Mäealuse 4, Tallinn 12618, Estonia
| | - Anna Kazantseva
- Protobios Llc, Mäealuse 4, Tallinn 12618, Estonia; Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
| | - Priit Pruunsild
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
| | | | - Tõnis Timmusk
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
| | | | - Kaia Palm
- Protobios Llc, Mäealuse 4, Tallinn 12618, Estonia; Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia.
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126
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Singh J, Wen X, Scales SJ. The Orphan G Protein-coupled Receptor Gpr175 (Tpra40) Enhances Hedgehog Signaling by Modulating cAMP Levels. J Biol Chem 2015; 290:29663-75. [PMID: 26451044 DOI: 10.1074/jbc.m115.665810] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Indexed: 11/06/2022] Open
Abstract
The Hedgehog (Hh) signaling pathway plays an essential role in vertebrate embryonic tissue patterning of many developing organs. Signaling occurs predominantly in primary cilia and is initiated by the entry of the G protein-coupled receptor (GPCR)-like protein Smoothened into cilia and culminates in gene transcription via the Gli family of transcription factors upon their nuclear entry. Here we identify an orphan GPCR, Gpr175 (also known as Tpra1 or Tpra40: transmembrane protein, adipocyte associated 1 or of 40 kDa), which also localizes to primary cilia upon Hh stimulation and positively regulates Hh signaling. Interaction experiments place Gpr175 at the level of PKA and upstream of the Gαi component of heterotrimeric G proteins, which itself localizes to cilia and can modulate Hh signaling. Gpr175 or Gαi1 depletion leads to increases in cellular cAMP levels and in Gli3 processing into its repressor form. Thus we propose that Gpr175 coupled to Gαi1 normally functions to inhibit the production of cAMP by adenylyl cyclase upon Hh stimulation, thus maximizing signaling by turning off PKA activity and hence Gli3 repressor formation. Taken together our data suggest that Gpr175 is a novel positive regulator of the Hh signaling pathway.
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Affiliation(s)
- Jaskirat Singh
- From the Department of Molecular Biology, Genentech, South San Francisco, California 94080
| | - Xiaohui Wen
- From the Department of Molecular Biology, Genentech, South San Francisco, California 94080
| | - Suzie J Scales
- From the Department of Molecular Biology, Genentech, South San Francisco, California 94080
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127
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Hyun J, Wang S, Kim J, Kim GJ, Jung Y. MicroRNA125b-mediated Hedgehog signaling influences liver regeneration by chorionic plate-derived mesenchymal stem cells. Sci Rep 2015; 5:14135. [PMID: 26370741 PMCID: PMC4569897 DOI: 10.1038/srep14135] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 08/17/2015] [Indexed: 12/16/2022] Open
Abstract
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.
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Affiliation(s)
- Jeongeun Hyun
- Department of Integrated Biological Science, Pusan, 609-735, Korea
| | - Sihyung Wang
- Department of Integrated Biological Science, Pusan, 609-735, Korea
| | - Jieun Kim
- Department of Integrated Biological Science, Pusan, 609-735, Korea
| | - Gi Jin Kim
- Department of Biomedical Science, CHA University, Seongnam, 463-400, Korea
| | - Youngmi Jung
- Department of Integrated Biological Science, Pusan, 609-735, Korea.,Department of Biological Sciences, College of Natural Science, Pusan National University, Pusan, 609-735, Korea
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128
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Kramann R, Fleig SV, Schneider RK, Fabian SL, DiRocco DP, Maarouf O, Wongboonsin J, Ikeda Y, Heckl D, Chang SL, Rennke HG, Waikar SS, Humphreys BD. Pharmacological GLI2 inhibition prevents myofibroblast cell-cycle progression and reduces kidney fibrosis. J Clin Invest 2015; 125:2935-51. [PMID: 26193634 PMCID: PMC4563736 DOI: 10.1172/jci74929] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Accepted: 06/04/2015] [Indexed: 12/21/2022] Open
Abstract
Chronic kidney disease is characterized by interstitial fibrosis and proliferation of scar-secreting myofibroblasts, ultimately leading to end-stage renal disease. The hedgehog (Hh) pathway transcriptional effectors GLI1 and GLI2 are expressed in myofibroblast progenitors; however, the role of these effectors during fibrogenesis is poorly understood. Here, we demonstrated that GLI2, but not GLI1, drives myofibroblast cell-cycle progression in cultured mesenchymal stem cell-like progenitors. In animals exposed to unilateral ureteral obstruction, Hh pathway suppression by expression of the GLI3 repressor in GLI1+ myofibroblast progenitors limited kidney fibrosis. Myofibroblast-specific deletion of Gli2, but not Gli1, also limited kidney fibrosis, and induction of myofibroblast-specific cell-cycle arrest mediated this inhibition. Pharmacologic targeting of this pathway with darinaparsin, an arsenical in clinical trials, reduced fibrosis through reduction of GLI2 protein levels and subsequent cell-cycle arrest in myofibroblasts. GLI2 overexpression rescued the cell-cycle effect of darinaparsin in vitro. While darinaparsin ameliorated fibrosis in WT and Gli1-KO mice, it was not effective in conditional Gli2-KO mice, supporting GLI2 as a direct darinaparsin target. The GLI inhibitor GANT61 also reduced fibrosis in mice. Finally, GLI1 and GLI2 were upregulated in the kidneys of patients with high-grade fibrosis. Together, these data indicate that GLI inhibition has potential as a therapeutic strategy to limit myofibroblast proliferation in kidney fibrosis.
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Affiliation(s)
- Rafael Kramann
- Renal Division, Brigham and Women’s Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
- Division of Nephrology and Clinical Immunology, RWTH Aachen University Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Susanne V. Fleig
- Renal Division, Brigham and Women’s Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
- Division of Nephrology and Hypertension, Hannover Medical School, Hannover, Germany
| | - Rebekka K. Schneider
- Division of Hematology, Brigham and Women’s Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Steven L. Fabian
- Renal Division, Brigham and Women’s Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Derek P. DiRocco
- Renal Division, Brigham and Women’s Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Omar Maarouf
- Renal Division, Brigham and Women’s Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Janewit Wongboonsin
- Renal Division, Brigham and Women’s Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Yoichiro Ikeda
- Renal Division, Brigham and Women’s Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Dirk Heckl
- Division of Hematology, Brigham and Women’s Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | | | - Helmut G. Rennke
- Department of Pathology, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Sushrut S. Waikar
- Renal Division, Brigham and Women’s Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Benjamin D. Humphreys
- Renal Division, Brigham and Women’s Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
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129
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Yoon JW, Lamm M, Iannaccone S, Higashiyama N, Leong KF, Iannaccone P, Walterhouse D. p53 modulates the activity of the GLI1 oncogene through interactions with the shared coactivator TAF9. DNA Repair (Amst) 2015; 34:9-17. [PMID: 26282181 DOI: 10.1016/j.dnarep.2015.06.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 06/11/2015] [Indexed: 01/20/2023]
Abstract
The GLI1 oncogene and p53 tumor suppressor gene function in an inhibitory loop that controls stem cell and tumor cell numbers. Since GLI1 and p53 both interact with the coactivator TATA Binding Protein Associated Factor 9 (TAF9), we hypothesized that competition between these transcription factors for TAF9 in cancer cells may contribute to the inhibitory loop and directly affect GLI1 function and cellular phenotype. We showed that TAF9 interacts with the oncogenic GLI family members GLI1 and GLI2 but not GLI3 in cell-free pull-down assays and with GLI1 in rhabdomyosarcoma and osteosarcoma cell lines. Removal of the TAF9-binding acidic alpha helical transactivation domain of GLI1 produced a significant reduction in the ability of GLI1 to transform cells. We then introduced a point mutation into GLI1 (L1052I) that eliminates TAF9 binding and a point mutation into GLI3 (I1510L) that establishes binding. Wild-type and mutant GLI proteins that bind TAF9 showed enhanced transactivating and cell transforming activity compared with those that did not. Therefore, GLI-TAF9 binding appears important for oncogenic activity. We then determined whether wild-type p53 down-regulates GLI function by sequestering TAF9. We showed that p53 binds TAF9 with greater affinity than does GLI1 and that co-expression of p53 with GLI1 or GLI2 down-regulated GLI-induced transactivation, which could be abrogated using mutant forms of GLI1 or p53. This suggests that p53 sequesters TAF9 from GLI1, which may contribute to inhibition of GLI1 activity by p53 and potentially impact therapeutic success of agents targeting GLI-TAF9 interactions in cancer.
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Affiliation(s)
- Joon Won Yoon
- Developmental Biology Program of the Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, IL 60611, USA
| | - Marilyn Lamm
- Developmental Biology Program of the Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, IL 60611, USA
| | - Stephen Iannaccone
- Developmental Biology Program of the Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, IL 60611, USA
| | - Nicole Higashiyama
- Developmental Biology Program of the Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, IL 60611, USA
| | - King Fu Leong
- Developmental Biology Program of the Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, IL 60611, USA
| | - Philip Iannaccone
- Developmental Biology Program of the Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, IL 60611, USA
| | - David Walterhouse
- Developmental Biology Program of the Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, IL 60611, USA.
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130
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Abstract
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.
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131
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Laclef C, Anselme I, Besse L, Catala M, Palmyre A, Baas D, Paschaki M, Pedraza M, Métin C, Durand B, Schneider-Maunoury S. The role of primary cilia in corpus callosum formation is mediated by production of the Gli3 repressor. Hum Mol Genet 2015; 24:4997-5014. [PMID: 26071364 DOI: 10.1093/hmg/ddv221] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 06/09/2015] [Indexed: 12/13/2022] Open
Abstract
Agenesis of the corpus callosum (AgCC) is a frequent brain disorder found in over 80 human congenital syndromes including ciliopathies. Here, we report a severe AgCC in Ftm/Rpgrip1l knockout mouse, which provides a valuable model for Meckel-Grüber syndrome. Rpgrip1l encodes a protein of the ciliary transition zone, which is essential for ciliogenesis in several cell types in mouse including neuroepithelial cells in the developing forebrain. We show that AgCC in Rpgrip1l(-/-) mouse is associated with a disturbed location of guidepost cells in the dorsomedial telencephalon. This mislocalization results from early patterning defects and abnormal cortico-septal boundary (CSB) formation in the medial telencephalon. We demonstrate that all these defects primarily result from altered GLI3 processing. Indeed, AgCC, together with patterning defects and mispositioning of guidepost cells, is rescued by overexpressing in Rpgrip1l(-/-) embryos, the short repressor form of the GLI3 transcription factor (GLI3R), provided by the Gli3(Δ699) allele. Furthermore, Gli3(Δ699) also rescues AgCC in Rfx3(-/-) embryos deficient for the ciliogenic RFX3 transcription factor that regulates the expression of several ciliary genes. These data demonstrate that GLI3 processing is a major outcome of primary cilia function in dorsal telencephalon morphogenesis. Rescuing CC formation in two independent ciliary mutants by GLI3(Δ699) highlights the crucial role of primary cilia in maintaining the proper level of GLI3R required for morphogenesis of the CC.
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Affiliation(s)
- Christine Laclef
- Sorbonne Universités, UPMC Univ Paris 06, UMR7622, CNRS, Institut de Biologie Paris Seine (IBPS)-Developmental Biology Laboratory, UMR7622, INSERM, ERL1156 and
| | - Isabelle Anselme
- Sorbonne Universités, UPMC Univ Paris 06, UMR7622, CNRS, Institut de Biologie Paris Seine (IBPS)-Developmental Biology Laboratory, UMR7622, INSERM, ERL1156 and
| | - Laurianne Besse
- Sorbonne Universités, UPMC Univ Paris 06, UMR7622, CNRS, Institut de Biologie Paris Seine (IBPS)-Developmental Biology Laboratory, UMR7622, INSERM, ERL1156 and
| | - Martin Catala
- Sorbonne Universités, UPMC Univ Paris 06, UMR7622, CNRS, Institut de Biologie Paris Seine (IBPS)-Developmental Biology Laboratory, UMR7622, INSERM, ERL1156 and Fédération de Neurologie, Groupe hospitalier Pitié-Salpêtrière-APHP, F-75013 Paris, France
| | - Aurélien Palmyre
- Sorbonne Universités, UPMC Univ Paris 06, UMR7622, CNRS, Institut de Biologie Paris Seine (IBPS)-Developmental Biology Laboratory, UMR7622, INSERM, ERL1156 and
| | - Dominique Baas
- Université Claude Bernard Lyon 1 and CNRS, CGPhiMC-UMR5534, F-69622 Villeurbanne, France and
| | - Marie Paschaki
- Université Claude Bernard Lyon 1 and CNRS, CGPhiMC-UMR5534, F-69622 Villeurbanne, France and
| | - Maria Pedraza
- Institut du Fer à Moulin, INSERM S839, F-75005 Paris, France, Sorbonne Université, UPMC Univ Paris 06, S839, Paris, France
| | - Christine Métin
- Institut du Fer à Moulin, INSERM S839, F-75005 Paris, France, Sorbonne Université, UPMC Univ Paris 06, S839, Paris, France
| | - Bénédicte Durand
- Université Claude Bernard Lyon 1 and CNRS, CGPhiMC-UMR5534, F-69622 Villeurbanne, France and
| | - Sylvie Schneider-Maunoury
- Sorbonne Universités, UPMC Univ Paris 06, UMR7622, CNRS, Institut de Biologie Paris Seine (IBPS)-Developmental Biology Laboratory, UMR7622, INSERM, ERL1156 and
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132
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Hsia EYC, Gui Y, Zheng X. Regulation of Hedgehog signaling by ubiquitination. FRONTIERS IN BIOLOGY 2015; 10:203-220. [PMID: 26366162 PMCID: PMC4564008 DOI: 10.1007/s11515-015-1343-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Hedgehog (Hh) signaling pathway plays crucial roles both in embryonic development and in adult stem cell function. The timing, duration and location of Hh signaling activity need to be tightly controlled. Abnormalities of Hh signal transduction lead to birth defects or malignant tumors. Recent data point to ubiquitination-related posttranslational modifications of several key Hh pathway components as an important mechanism of regulation of the Hh pathway. Here we review how ubiquitination regulates the localization, stability and activity of the key Hh signaling components.
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Affiliation(s)
- Elaine Y. C. Hsia
- Department of Anatomy and Regenerative Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Yirui Gui
- Department of Anatomy and Regenerative Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Xiaoyan Zheng
- Department of Anatomy and Regenerative Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
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133
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Arnhold IJP, França MM, Carvalho LR, Mendonca BB, Jorge AAL. Role of GLI2 in hypopituitarism phenotype. J Mol Endocrinol 2015; 54:R141-50. [PMID: 25878059 DOI: 10.1530/jme-15-0009] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/01/2015] [Indexed: 02/01/2023]
Abstract
GLI2 is a zinc-finger transcription factor involved in the Sonic Hedgehog pathway. Gli2 mutant mice have hypoplastic anterior and absent posterior pituitary glands. We reviewed the literature for patients with hypopituitarism and alterations in GLI2. Twenty-five patients (16 families) had heterozygous truncating mutations, and the phenotype frequently included GH deficiency, a small anterior pituitary lobe and an ectopic/undescended posterior pituitary lobe on magnetic resonance imaging and postaxial polydactyly. The inheritance pattern was autosomal dominant with incomplete penetrance and variable expressivity. The mutation was frequently inherited from an asymptomatic parent. Eleven patients had heterozygous non-synonymous GLI2 variants that were classified as variants of unknown significance, because they were either absent from or had a frequency lower than 0.001 in the databases. In these patients, the posterior pituitary was also ectopic, but none had polydactyly. A third group of variants found in patients with hypopituitarism were considered benign because their frequency was ≥ 0.001 in the databases. GLI2 is a large and polymorphic gene, and sequencing may identify variants whose interpretation may be difficult. Incomplete penetrance implies in the participation of other genetic and/or environmental factors. An interaction between Gli2 mutations and prenatal ethanol exposure has been demonstrated in mice dysmorphology. In conclusion, a relatively high frequency of GLI2 mutations and variants were identified in patients with congenital GH deficiency without other brain defects, and most of these patients presented with combined pituitary hormone deficiency and an ectopic posterior pituitary lobe. Future studies may clarify the relative role and frequency of GLI2 alterations in the aetiology of hypopituitarism.
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Affiliation(s)
- Ivo J P Arnhold
- Divisão de EndocrinologiaUnidade de Endocrinologia do Desenvolvimento, Laboratorio de Hormonios e Genetica Molecular LIM/42, Hospital das Clinicas da FMUSP, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, Avenida Eneas de Carvalho Aguiar, 155, Prédio dos Ambulatórios, 8° andar, Bloco 3, CEP 05403-900 Sao Paulo, BrazilUnidade de Endocrinologia GeneticaLaboratorio de Endocrinologia Celular e Molecular LIM/25, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, 01246-903 Sao Paulo, Brazil
| | - Marcela M França
- Divisão de EndocrinologiaUnidade de Endocrinologia do Desenvolvimento, Laboratorio de Hormonios e Genetica Molecular LIM/42, Hospital das Clinicas da FMUSP, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, Avenida Eneas de Carvalho Aguiar, 155, Prédio dos Ambulatórios, 8° andar, Bloco 3, CEP 05403-900 Sao Paulo, BrazilUnidade de Endocrinologia GeneticaLaboratorio de Endocrinologia Celular e Molecular LIM/25, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, 01246-903 Sao Paulo, Brazil
| | - Luciani R Carvalho
- Divisão de EndocrinologiaUnidade de Endocrinologia do Desenvolvimento, Laboratorio de Hormonios e Genetica Molecular LIM/42, Hospital das Clinicas da FMUSP, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, Avenida Eneas de Carvalho Aguiar, 155, Prédio dos Ambulatórios, 8° andar, Bloco 3, CEP 05403-900 Sao Paulo, BrazilUnidade de Endocrinologia GeneticaLaboratorio de Endocrinologia Celular e Molecular LIM/25, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, 01246-903 Sao Paulo, Brazil
| | - Berenice B Mendonca
- Divisão de EndocrinologiaUnidade de Endocrinologia do Desenvolvimento, Laboratorio de Hormonios e Genetica Molecular LIM/42, Hospital das Clinicas da FMUSP, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, Avenida Eneas de Carvalho Aguiar, 155, Prédio dos Ambulatórios, 8° andar, Bloco 3, CEP 05403-900 Sao Paulo, BrazilUnidade de Endocrinologia GeneticaLaboratorio de Endocrinologia Celular e Molecular LIM/25, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, 01246-903 Sao Paulo, Brazil
| | - Alexander A L Jorge
- Divisão de EndocrinologiaUnidade de Endocrinologia do Desenvolvimento, Laboratorio de Hormonios e Genetica Molecular LIM/42, Hospital das Clinicas da FMUSP, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, Avenida Eneas de Carvalho Aguiar, 155, Prédio dos Ambulatórios, 8° andar, Bloco 3, CEP 05403-900 Sao Paulo, BrazilUnidade de Endocrinologia GeneticaLaboratorio de Endocrinologia Celular e Molecular LIM/25, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, 01246-903 Sao Paulo, Brazil
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134
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Messina A, Lan L, Incitti T, Bozza A, Andreazzoli M, Vignali R, Cremisi F, Bozzi Y, Casarosa S. Noggin-Mediated Retinal Induction Reveals a Novel Interplay Between Bone Morphogenetic Protein Inhibition, Transforming Growth Factor β, and Sonic Hedgehog Signaling. Stem Cells 2015; 33:2496-508. [PMID: 25913744 DOI: 10.1002/stem.2043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 03/12/2015] [Accepted: 04/02/2015] [Indexed: 01/27/2023]
Abstract
It has long been known that the depletion of bone morphogenetic protein (BMP) is one of the key factors necessary for the development of anterior neuroectodermal structures. However, the precise molecular mechanisms that underlie forebrain regionalization are still not completely understood. Here, we show that Noggin1 is involved in the regionalization of anterior neural structures in a dose-dependent manner. Low doses of Noggin1 expand prosencephalic territories, while higher doses specify diencephalic and retinal regions at the expense of telencephalic areas. A similar dose-dependent mechanism determines the ability of Noggin1 to convert pluripotent cells in prosencephalic or diencephalic/retinal precursors, as shown by transplant experiments and molecular analyses. At a molecular level, the strong inhibition of BMP signaling exerted by high doses of Noggin1 reinforces the Nodal/transforming growth factor (TGF)β signaling pathway, leading to activation of Gli1 and Gli2 and subsequent activation of Sonic Hedgehog (SHH) signaling. We propose a new role for Noggin1 in determining specific anterior neural structures by the modulation of TGFβ and SHH signaling.
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Affiliation(s)
| | - Lei Lan
- Department of Biology, University of Pisa, Pisa, Italy
| | | | | | | | | | | | - Yuri Bozzi
- CIBIO, University of Trento, Trento, Italy.,CNR Institute of Neuroscience, Pisa, Italy
| | - Simona Casarosa
- CIBIO, University of Trento, Trento, Italy.,CNR Institute of Neuroscience, Pisa, Italy
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135
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Indian hedgehog contributes to human cartilage endplate degeneration. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2015; 24:1720-8. [PMID: 25958162 DOI: 10.1007/s00586-015-4000-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 05/03/2015] [Accepted: 05/03/2015] [Indexed: 10/23/2022]
Abstract
PURPOSE To determine the role of Indian hedgehog (Ihh) signaling in human cartilage endplate (CEP) degeneration. METHODS CEP-degenerated tissues from patients with Modic I or II changes (n = 9 and 45, respectively) and normal tissues from vertebral burst fracture patients (n = 17) were collected. Specimens were either cut into slices for organ culture ex vivo or digested to isolate chondrocytes for cell culture in vitro. Ihh expression and the effect of Ihh on cartilage degeneration were determined by investigating degeneration markers in this study. RESULTS Ihh expression and cartilage degeneration markers significantly increased in the Modic I and II groups. The expression of cartilage degeneration markers was positively correlated with degeneration severity. Gain-of-function for Ihh promoted expression of cartilage degeneration markers in vitro, while loss-of-function for Ihh inhibited their expression both in vitro and ex vivo. CONCLUSIONS These findings demonstrated that Ihh promotes CEP degeneration. Blocking Ihh pathway has potential clinical usage for attenuating CEP degeneration.
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136
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Gregory LC, Gaston-Massuet C, Andoniadou CL, Carreno G, Webb EA, Kelberman D, McCabe MJ, Panagiotakopoulos L, Saldanha JW, Spoudeas HA, Torpiano J, Rossi M, Raine J, Canham N, Martinez-Barbera JP, Dattani MT. The role of the sonic hedgehog signalling pathway in patients with midline defects and congenital hypopituitarism. Clin Endocrinol (Oxf) 2015; 82:728-38. [PMID: 25327282 DOI: 10.1111/cen.12637] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 08/22/2014] [Accepted: 10/13/2014] [Indexed: 01/28/2023]
Abstract
INTRODUCTION The Gli family of zinc finger (GLI) transcription factors mediates the sonic hedgehog signalling pathway (HH) essential for CNS, early pituitary and ventral forebrain development in mice. Human mutations in this pathway have been described in patients with holoprosencephaly (HPE), isolated congenital hypopituitarism (CH) and cranial/midline facial abnormalities. Mutations in Sonic hedgehog (SHH) have been associated with HPE but not CH, despite murine studies indicating involvement in pituitary development. OBJECTIVES/METHODS We aimed to establish the role of the HH pathway in the aetiology of hypothalamo-pituitary disorders by screening our cohort of patients with midline defects and/or CH for mutations in SHH, GLI2, Shh brain enhancer 2 (SBE2) and growth-arrest specific 1 (GAS1). RESULTS Two variants and a deletion of GLI2 were identified in three patients. A novel variant at a highly conserved residue in the zinc finger DNA-binding domain, c.1552G > A [pE518K], was identified in a patient with growth hormone deficiency and low normal free T4. A nonsynonymous variant, c.2159G > A [p.R720H], was identified in a patient with a short neck, cleft palate and hypogonadotrophic hypogonadism. A 26·6 Mb deletion, 2q12·3-q21·3, encompassing GLI2 and 77 other genes, was identified in a patient with short stature and impaired growth. Human embryonic expression studies and molecular characterisation of the GLI2 mutant p.E518K support the potential pathogenicity of GLI2 mutations. No mutations were identified in GAS1 or SBE2. A novel SHH variant, c.1295T>A [p.I432N], was identified in two siblings with variable midline defects but normal pituitary function. CONCLUSIONS Our data suggest that mutations in SHH, GAS1 and SBE2 are not associated with hypopituitarism, although GLI2 is an important candidate for CH.
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Affiliation(s)
- L C Gregory
- Genetics and Epigenetics in Health and Disease Section, Genetics and Genomic Medicine Programme, UCL Institute of Child Health, London, UK
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Minhas R, Pauls S, Ali S, Doglio L, Khan MR, Elgar G, Abbasi AA. Cis-regulatory control of human GLI2 expression in the developing neural tube and limb bud. Dev Dyn 2015; 244:681-92. [DOI: 10.1002/dvdy.24266] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 01/29/2015] [Accepted: 02/16/2015] [Indexed: 11/08/2022] Open
Affiliation(s)
- Rashid Minhas
- National Center for Bioinformatics; Program of Comparative and Evolutionary Genomics; Faculty of Biological Sciences; Quaid-i-Azam University; Islamabad 45320 Pakistan
| | - Stefan Pauls
- Division of Systems Biology; MRC National Institute for Medical Research; The Ridgeway, Mill Hill London NW7 1AA United Kingdom
| | - Shahid Ali
- National Center for Bioinformatics; Program of Comparative and Evolutionary Genomics; Faculty of Biological Sciences; Quaid-i-Azam University; Islamabad 45320 Pakistan
| | - Laura Doglio
- Division of Systems Biology; MRC National Institute for Medical Research; The Ridgeway, Mill Hill London NW7 1AA United Kingdom
| | - Muhammad Ramzan Khan
- National Institute for Genomics and Advanced Biotechnology; National Agricultural Research Center; Park Road Islamabad Pakistan
| | - Greg Elgar
- Division of Systems Biology; MRC National Institute for Medical Research; The Ridgeway, Mill Hill London NW7 1AA United Kingdom
| | - Amir Ali Abbasi
- National Center for Bioinformatics; Program of Comparative and Evolutionary Genomics; Faculty of Biological Sciences; Quaid-i-Azam University; Islamabad 45320 Pakistan
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138
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Hedgehog signaling activates a positive feedback mechanism involving insulin-like growth factors to induce osteoblast differentiation. Proc Natl Acad Sci U S A 2015; 112:4678-83. [PMID: 25825734 DOI: 10.1073/pnas.1502301112] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Hedgehog (Hh) signaling is essential for osteoblast differentiation in the endochondral skeleton during embryogenesis. However, the molecular mechanism underlying the osteoblastogenic role of Hh is not completely understood. Here, we report that Hh markedly induces the expression of insulin-like growth factor 2 (Igf2) that activates the mTORC2-Akt signaling cascade during osteoblast differentiation. Igf2-Akt signaling, in turn, stabilizes full-length Gli2 through Serine 230, thus enhancing the output of transcriptional activation by Hh. Importantly, genetic deletion of the Igf signaling receptor Igf1r specifically in Hh-responding cells diminishes bone formation in the mouse embryo. Thus, Hh engages Igf signaling in a positive feedback mechanism to activate the osteogenic program.
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139
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Kong Y, Peng Y, Liu Y, Xin H, Zhan X, Tan W. Twist1 and Snail Link Hedgehog Signaling to Tumor-Initiating Cell-Like Properties and Acquired Chemoresistance Independently of ABC Transporters. Stem Cells 2015; 33:1063-74. [DOI: 10.1002/stem.1955] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Revised: 12/12/2014] [Accepted: 12/23/2014] [Indexed: 12/30/2022]
Affiliation(s)
- Ying Kong
- Department of Pharmacology; School of Pharmacy; Fudan University; Shanghai People's Republic of China
| | - Yuanqiu Peng
- Department of Pharmacology; School of Pharmacy; Fudan University; Shanghai People's Republic of China
| | - Yuan Liu
- Department of Pharmacology; School of Pharmacy; Fudan University; Shanghai People's Republic of China
| | - Hong Xin
- Department of Pharmacology; School of Pharmacy; Fudan University; Shanghai People's Republic of China
| | - Xia Zhan
- Department of Pharmacology; School of Pharmacy; Fudan University; Shanghai People's Republic of China
| | - Wenfu Tan
- Department of Pharmacology; School of Pharmacy; Fudan University; Shanghai People's Republic of China
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140
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Makino S, Zhulyn O, Mo R, Puviindran V, Zhang X, Murata T, Fukumura R, Ishitsuka Y, Kotaki H, Matsumaru D, Ishii S, Hui CC, Gondo Y. T396I mutation of mouse Sufu reduces the stability and activity of Gli3 repressor. PLoS One 2015; 10:e0119455. [PMID: 25760946 PMCID: PMC4356511 DOI: 10.1371/journal.pone.0119455] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 01/22/2015] [Indexed: 01/20/2023] Open
Abstract
Hedgehog signaling is primarily transduced by two transcription factors: Gli2, which mainly acts as a full-length activator, and Gli3, which tends to be proteolytically processed from a full-length form (Gli3FL) to an N-terminal repressor (Gli3REP). Recent studies using a Sufu knockout mouse have indicated that Sufu is involved in regulating Gli2 and Gli3 activator and repressor activity at multiple steps of the signaling cascade; however, the mechanism of specific Gli2 and Gli3 regulation remains to be elucidated. In this study, we established an allelic series of ENU-induced mouse strains. Analysis of one of the missense alleles, SufuT396I, showed that Thr396 residue of Sufu played a key role in regulation of Gli3 activity. SufuT396I/T396I embryos exhibited severe polydactyly, which is indicative of compromised Gli3 activity. Concomitantly, significant quantitative reductions of unprocessed Gli3 (Gli3FL) and processed Gli3 (Gli3REP) were observed in vivo as well as in vitro. Genetic experiments showed that patterning defects in the limb buds of SufuT396I/T396I were rescued by a constitutive Gli3REP allele (Gli3∆699), strongly suggesting that SufuT396I reduced the truncated Gli3 repressor. In contrast, SufuT396I qualitatively exhibited no mutational effects on Gli2 regulation. Taken together, the results of this study show that the Thr396 residue of Sufu is specifically required for regulation of Gli3 but not Gli2. This implies a novel Sufu-mediated mechanism in which Gli2 activator and Gli3 repressor are differentially regulated.
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Affiliation(s)
- Shigeru Makino
- Mutagenesis and Genomics Team, RIKEN BioResource Center, Tsukuba, Ibaraki, Japan
- * E-mail:
| | - Olena Zhulyn
- Department of Molecular Genetics, University of Toronto and Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Rong Mo
- Department of Molecular Genetics, University of Toronto and Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Vijitha Puviindran
- Department of Molecular Genetics, University of Toronto and Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Xiaoyun Zhang
- Department of Molecular Genetics, University of Toronto and Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Takuya Murata
- Mutagenesis and Genomics Team, RIKEN BioResource Center, Tsukuba, Ibaraki, Japan
| | - Ryutaro Fukumura
- Mutagenesis and Genomics Team, RIKEN BioResource Center, Tsukuba, Ibaraki, Japan
| | - Yuichi Ishitsuka
- Mutagenesis and Genomics Team, RIKEN BioResource Center, Tsukuba, Ibaraki, Japan
| | - Hayato Kotaki
- Mutagenesis and Genomics Team, RIKEN BioResource Center, Tsukuba, Ibaraki, Japan
| | - Daisuke Matsumaru
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Wakayama, Japan
| | - Shunsuke Ishii
- Laboratory of Molecular Genetics, RIKEN Tsukuba Institute, Tsukuba, Ibaraki, Japan
| | - Chi-Chung Hui
- Department of Molecular Genetics, University of Toronto and Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Yoichi Gondo
- Mutagenesis and Genomics Team, RIKEN BioResource Center, Tsukuba, Ibaraki, Japan
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141
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Kugler MC, Joyner AL, Loomis CA, Munger JS. Sonic hedgehog signaling in the lung. From development to disease. Am J Respir Cell Mol Biol 2015; 52:1-13. [PMID: 25068457 DOI: 10.1165/rcmb.2014-0132tr] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Over the past two decades, the secreted protein sonic hedgehog (SHH) has emerged as a critical morphogen during embryonic lung development, regulating the interaction between epithelial and mesenchymal cell populations in the airway and alveolar compartments. There is increasing evidence that the SHH pathway is active in adult lung diseases such as pulmonary fibrosis, asthma, chronic obstructive pulmonary disease, and lung cancer, which raises two questions: (1) What role does SHH signaling play in these diseases? and (2) Is it a primary driver of the disease or a response (perhaps beneficial) to the primary disturbance? In this review we aim to fill the gap between the well-studied period of embryonic lung development and the adult diseased lung by reviewing the hedgehog (HH) pathway during the postnatal period and in adult uninjured and injured lungs. We elucidate the similarities and differences in the epithelial-mesenchymal interplay during the fibrosis response to injury in lung compared with other organs and present a critical appraisal of tools and agents available to evaluate HH signaling.
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142
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Li DD, Pang HG, Song JN, Zhao YL, Zhang BF, Ma XD, Sun P. Receptor-associated protein promotes t-PA expression, reduces PAI-1 expression and improves neurorecovery after acute ischemic stroke. J Neurol Sci 2015; 350:84-9. [DOI: 10.1016/j.jns.2015.02.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 01/19/2015] [Accepted: 02/10/2015] [Indexed: 12/11/2022]
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143
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Hedgehog signaling in prostate epithelial-mesenchymal growth regulation. Dev Biol 2015; 400:94-104. [PMID: 25641695 DOI: 10.1016/j.ydbio.2015.01.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 01/16/2015] [Accepted: 01/20/2015] [Indexed: 12/24/2022]
Abstract
The prostate gland plays an important role in male reproduction, and is also an organ prone to diseases such as benign prostatic hyperplasia (BPH) and prostate cancer. The prostate consists of ducts with an inner layer of epithelium surrounded by stroma. Reciprocal signaling between these two cell compartments is instrumental to normal prostatic development, homeostasis, regeneration, as well as tumor formation. Hedgehog (HH) signaling is a master regulator in numerous developmental processes. In many organs, HH plays a key role in epithelial-mesenchymal signaling that regulates organ growth and tissue differentiation, and abnormal HH signaling has been implicated in the progression of various epithelial carcinomas. In this review, we focus on recent studies exploring the multipotency of endogenous postnatal and adult epithelial and stromal stem cells and studies addressing the role of HH in prostate development and cancer. We discuss the implications of the results for a new understanding of prostate development and disease. Insight into the cellular and molecular mechanisms underlying epithelial-mesenchymal growth regulation should provide a basis for devising innovative therapies to combat diseases of the prostate.
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144
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Carpenter BS, Barry RL, Verhey KJ, Allen BL. The heterotrimeric kinesin-2 complex interacts with and regulates GLI protein function. J Cell Sci 2015; 128:1034-50. [PMID: 25588831 DOI: 10.1242/jcs.162552] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
GLI transport to the primary cilium and nucleus is required for proper Hedgehog (HH) signaling; however, the mechanisms that mediate these trafficking events are poorly understood. Kinesin-2 motor proteins regulate ciliary transport of cargo, yet their role in GLI protein function remains unexplored. To examine a role for the heterotrimeric KIF3A-KIF3B-KAP3 kinesin-2 motor complex in regulating GLI activity, we performed a series of structure-function analyses using biochemical, cell signaling and in vivo approaches that define novel specific interactions between GLI proteins and two components of this complex, KAP3 and KIF3A. We find that all three mammalian GLI proteins interact with KAP3 and we map specific interaction sites in both proteins. Furthermore, we find that GLI proteins interact selectively with KIF3A, but not KIF3B, and that GLI interacts synergistically with KAP3 and KIF3A. Using a combination of cell signaling assays and chicken in ovo electroporation, we demonstrate that KAP3 interactions restrict GLI activator function but not GLI repressor function. These data suggest that GLI interactions with KIF3A-KIF3B-KAP3 complexes are essential for proper GLI transcriptional activity.
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Affiliation(s)
- Brandon S Carpenter
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Renee L Barry
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Kristen J Verhey
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Benjamin L Allen
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
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145
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Tang C, Pan Y, Luo H, Xiong W, Zhu H, Ruan H, Wang J, Zou C, Tang L, Iguchi T, Long F, Wu X. Hedgehog signaling stimulates the conversion of cholesterol to steroids. Cell Signal 2015; 27:487-97. [PMID: 25582983 DOI: 10.1016/j.cellsig.2015.01.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Revised: 12/19/2014] [Accepted: 01/05/2015] [Indexed: 12/28/2022]
Abstract
Cholesterol modification of Hedgehog (Hh) ligands is fundamental for the activity of Hh signaling, and cholesterol biosynthesis is also required for intracellular Hh signaling transduction. Here, we investigated the roles and underlying mechanism of Hh signaling in metabolism of cholesterol. The main components of the Hh pathway are abundantly expressed in both human cytotrophoblasts and trophoblast-like cells. Activation of Hh signaling induces the conversion of cholesterol to progesterone (P4) and estradiol (E2) through up-regulating the expression of steroidogenic enzymes including P450 cholesterol side chain cleavage enzyme (P450scc), 3β-hydroxysteroid dehydrogenase type 1 (3β-HSD1), and aromatase. Moreover, inhibition of Hh signaling attenuates not only Hh-induced expression of steroidogenic enzymes but also the conversion of cholesterol to P4 and E2. Whereas Gli3 is required for Hh-induced P450scc expression, Gli2 mediates the induction of 3β-HSD1 and aromatase. Finally, in ovariectomized nude mice, systemic inhibition of Hh signaling by cyclopamine suppresses circulating P4 and E2 levels derived from a trophoblast-like choricarcinoma xenograft, and attenuates uterine response to P4 and E2. Together these results uncover a hitherto uncharacterized role of Hh signaling in metabolism of cholesterol.
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Affiliation(s)
- Chao Tang
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Yibin Pan
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Huan Luo
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Wenyi Xiong
- The Affiliated Children Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Haibin Zhu
- The Affiliated First Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Hongfeng Ruan
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Jirong Wang
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Chaochun Zou
- The Affiliated Children Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Lanfang Tang
- The Affiliated Children Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Takuma Iguchi
- Department of Toxicology, Osaka University, Suita, Osaka 565-0871, Japan
| | - Fanxin Long
- Departments of Orthopaedic Surgery, Medicine and Developmental Biology Washington University in St. Louis, MO, 63110, USA
| | - Ximei Wu
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, 310058, China; Departments of Orthopaedic Surgery, Medicine and Developmental Biology Washington University in St. Louis, MO, 63110, USA.
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146
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Schmidt-Heck W, Matz-Soja M, Aleithe S, Marbach E, Guthke R, Gebhardt R. Fuzzy modeling reveals a dynamic self-sustaining network of the GLI transcription factors controlling important metabolic regulators in adult mouse hepatocytes. MOLECULAR BIOSYSTEMS 2015; 11:2190-7. [DOI: 10.1039/c5mb00129c] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The Hedgehog signalling-driven Gli transcription factors in hepatocytes form a regulatory network identified by a fuzzy-logic modelling approach. The network explains dynamic features important for hepatocyte function and fate.
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Affiliation(s)
- Wolfgang Schmidt-Heck
- Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute
- 07745 Jena
- Germany
| | - Madlen Matz-Soja
- Institute of Biochemistry
- Faculty of Medicine
- University of Leipzig
- 04103 Leipzig
- Germany
| | - Susanne Aleithe
- Institute of Biochemistry
- Faculty of Medicine
- University of Leipzig
- 04103 Leipzig
- Germany
| | - Eugenia Marbach
- Institute of Biochemistry
- Faculty of Medicine
- University of Leipzig
- 04103 Leipzig
- Germany
| | - Reinhard Guthke
- Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute
- 07745 Jena
- Germany
| | - Rolf Gebhardt
- Institute of Biochemistry
- Faculty of Medicine
- University of Leipzig
- 04103 Leipzig
- Germany
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147
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Liu YC, Couzens AL, Deshwar AR, B McBroom-Cerajewski LD, Zhang X, Puviindran V, Scott IC, Gingras AC, Hui CC, Angers S. The PPFIA1-PP2A protein complex promotes trafficking of Kif7 to the ciliary tip and Hedgehog signaling. Sci Signal 2014; 7:ra117. [PMID: 25492966 DOI: 10.1126/scisignal.2005608] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The primary cilium is required for Hedgehog (Hh) signaling in vertebrates. Hh leads to ciliary accumulation and activation of the transmembrane protein Smoothened (Smo) and affects the localization of several pathway components, including the Gli family of transcriptional regulators, within different regions of primary cilia. Genetic analysis indicates that the kinesin protein Kif7 both promotes and inhibits mouse Hh signaling. Using mass spectrometry, we identified liprin-α1 (PPFIA1) and the protein phosphatase PP2A as Kif7-interacting proteins, and we showed that they were important for the trafficking of Kif7 and Gli proteins to the tips of cilia and for the transcriptional output of Hh signaling. Our results suggested that PPFIA1 functioned with PP2A to promote the dephosphorylation of Kif7, triggering Kif7 localization to the tips of primary cilia and promoting Gli transcriptional activity.
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Affiliation(s)
- Yulu C Liu
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Amber L Couzens
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
| | - Ashish R Deshwar
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | | | - Xiaoyun Zhang
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Vijitha Puviindran
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Ian C Scott
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada. Program in Developmental and Stem Cell Biology, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada. Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Chi-Chung Hui
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada. Program in Developmental and Stem Cell Biology, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Stephane Angers
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada. Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
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148
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Liu JT, Bain LJ. Arsenic inhibits hedgehog signaling during P19 cell differentiation. Toxicol Appl Pharmacol 2014; 281:243-53. [PMID: 25448440 DOI: 10.1016/j.taap.2014.10.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 10/02/2014] [Accepted: 10/14/2014] [Indexed: 11/30/2022]
Abstract
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.
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Affiliation(s)
- Jui Tung Liu
- Environmental Toxicology Program, Clemson University, 132 Long Hall, Clemson, SC 29634, USA
| | - Lisa J Bain
- Environmental Toxicology Program, Clemson University, 132 Long Hall, Clemson, SC 29634, USA; Department of Biological Sciences, Clemson University, 132 Long Hall, Clemson, SC 29634, USA.
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149
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Swiderski RE, Nakano Y, Mullins RF, Seo S, Bánfi B. A mutation in the mouse ttc26 gene leads to impaired hedgehog signaling. PLoS Genet 2014; 10:e1004689. [PMID: 25340710 PMCID: PMC4207615 DOI: 10.1371/journal.pgen.1004689] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 08/19/2014] [Indexed: 12/21/2022] Open
Abstract
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. The Hedgehog (Hh) signaling pathway determines pattern formation in many developing tissues, e.g., during digit formation in the limbs, by regulating proteins of the Gli family. Activation of these proteins requires their transport to the tip of the primary cilium (an antenna-like sensory structure of the cell), and subsequent dissociation from their negative regulator, Sufu. Little is known about the mechanism underlying this dissociation. To gain new insights into Hh signaling, we analyzed the mutant mouse hop-sterile (hop), whose developmental defects suggest that the primary cilia are dysfunctional. We discovered that the hop mutation lies in the Ttc26 gene, and that levels of the encoded protein are low in hop mice. Normal Ttc26 was found to bind to Intraflagellar Transport (IFT) complex B, a structure essential for building the cilium and moving proteins towards its tip. Nevertheless, unlike previously characterized mutations that affect IFT complex B, hop did not interfere with either the formation of primary cilia or the accumulation of Gli at their tips, but rather with dissociation of Gli from Sufu. Our results provide novel insights into Hh signaling, demonstrating that efficient coupling between Gli's accumulation at the ciliary tip and its dissociation from Sufu depends on Ttc26.
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Affiliation(s)
- Ruth E Swiderski
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America; Inflammation Program, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Yoko Nakano
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America; Inflammation Program, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Robert F Mullins
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Seongjin Seo
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Botond Bánfi
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America; Inflammation Program, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America; Department of Otolaryngology - Head and Neck Surgery, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America; Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
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Jiang Z, Cushing L, Ai X, Lü J. miR-326 is downstream of Sonic hedgehog signaling and regulates the expression of Gli2 and smoothened. Am J Respir Cell Mol Biol 2014; 51:273-83. [PMID: 24617895 DOI: 10.1165/rcmb.2013-0127oc] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
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.
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Affiliation(s)
- Zhihua Jiang
- 1 Pulmonary Center, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts; and
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