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Zeni C, Komiya Y, Habas R. Formin Binding Protein 1 (FNBP1) regulates non-canonical Wnt signaling and vertebrate gastrulation. Dev Biol 2024; 515:18-29. [PMID: 38945423 PMCID: PMC11317212 DOI: 10.1016/j.ydbio.2024.06.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 06/19/2024] [Accepted: 06/24/2024] [Indexed: 07/02/2024]
Abstract
The Formin protein Daam1 is required for Wnt-induced cytoskeletal changes during gastrulation, though how it accomplishes this remains unresolved. Here we report the characterization of Formin Binding Protein 1 (FNBP1) as a binding partner of Daam1. The interaction of Daam1 with FNBP1 and its domains required for this interaction were delineated. Immunofluorescence studies showed FNBP1 co-localizes with Daam1, and is an integral component of the actin cytoskeletal complex that is responsive to Wnt stimulation. Specifically, FNBP1 can induce intracellular tubule-like structures and localize to focal adhesions suggesting a role for FNBP1 in cell migration. Functional FNBP1 studies in Xenopus embryos uncover a critical role for FNBP1 in regulating vertebrate gastrulation. Additionally, suboptimal doses of Daam1 and FNBP1 synergize to produce severe gastrulation defects, indicating FNBP1 and Daam1 may function within the same signaling pathway. These results together show FNBP1 is an integral component of Daam1-regulated non-canonical Wnt signaling required for vertebrate gastrulation.
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Affiliation(s)
- Courtney Zeni
- Department of Biology, Temple University, Philadelphia, PA, 19122, USA
| | - Yuko Komiya
- Department of Biology, Temple University, Philadelphia, PA, 19122, USA
| | - Raymond Habas
- Department of Biology, Temple University, Philadelphia, PA, 19122, USA.
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2
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Song P, Gao Z, Bao Y, Chen L, Huang Y, Liu Y, Dong Q, Wei X. Wnt/β-catenin signaling pathway in carcinogenesis and cancer therapy. J Hematol Oncol 2024; 17:46. [PMID: 38886806 PMCID: PMC11184729 DOI: 10.1186/s13045-024-01563-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Accepted: 05/31/2024] [Indexed: 06/20/2024] Open
Abstract
The Wnt/β-catenin signaling pathway plays a crucial role in various physiological processes, encompassing development, tissue homeostasis, and cell proliferation. Under normal physiological conditions, the Wnt/β-catenin signaling pathway is meticulously regulated. However, aberrant activation of this pathway and downstream target genes can occur due to mutations in key components of the Wnt/β-catenin pathway, epigenetic modifications, and crosstalk with other signaling pathways. Consequently, these dysregulations contribute significantly to tumor initiation and progression. Therapies targeting the Wnt/β-catenin signaling transduction have exhibited promising prospects and potential for tumor treatment. An increasing number of medications targeting this pathway are continuously being developed and validated. This comprehensive review aims to summarize the latest advances in our understanding of the role played by the Wnt/β-catenin signaling pathway in carcinogenesis and targeted therapy, providing valuable insights into acknowledging current opportunities and challenges associated with targeting this signaling pathway in cancer research and treatment.
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Affiliation(s)
- Pan Song
- Department of Urology, Institute of Urology, West China Hospital of Sichuan University, Chengdu, Sichuan Province, 610041, China
| | - Zirui Gao
- Laboratory of Aging Research and Cancer Agent Target, State Key Laboratory of Biotherapy, Cancer Center, West China Hospital, National Clinical Research Center for Geriatrics, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan, 610041, P.R. China
| | - Yige Bao
- Department of Urology, Institute of Urology, West China Hospital of Sichuan University, Chengdu, Sichuan Province, 610041, China
| | - Li Chen
- Laboratory of Aging Research and Cancer Agent Target, State Key Laboratory of Biotherapy, Cancer Center, West China Hospital, National Clinical Research Center for Geriatrics, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan, 610041, P.R. China
| | - Yuhe Huang
- Laboratory of Aging Research and Cancer Agent Target, State Key Laboratory of Biotherapy, Cancer Center, West China Hospital, National Clinical Research Center for Geriatrics, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan, 610041, P.R. China
| | - Yanyan Liu
- Laboratory of Aging Research and Cancer Agent Target, State Key Laboratory of Biotherapy, Cancer Center, West China Hospital, National Clinical Research Center for Geriatrics, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan, 610041, P.R. China
| | - Qiang Dong
- Department of Urology, Institute of Urology, West China Hospital of Sichuan University, Chengdu, Sichuan Province, 610041, China.
| | - Xiawei Wei
- Laboratory of Aging Research and Cancer Agent Target, State Key Laboratory of Biotherapy, Cancer Center, West China Hospital, National Clinical Research Center for Geriatrics, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan, 610041, P.R. China.
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Liu J, Peng D, You J, Zhou O, Qiu H, Hao C, Chen H, Fu Z, Zou L. Type 2 Alveolar Epithelial Cells Differentiated from Human Umbilical Cord Mesenchymal Stem Cells Alleviate Mouse Pulmonary Fibrosis Through β-Catenin-Regulated Cell Apoptosis. Stem Cells Dev 2021; 30:660-670. [PMID: 33899513 DOI: 10.1089/scd.2020.0208] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Pulmonary fibrosis (PF) is a chronic, progressive, and lethal disease with little response to available therapies. One of the major mechanisms of PF is the repeated injury and inadequate regeneration of the alveolar epithelium. In this study, we induced human umbilical cord mesenchymal stem cells (hUC-MSCs) to differentiate into type 2 alveolar epithelial cells (AEC2s), and we provided evidence that intratracheal transplantation of hUC-MSC-derived AEC2s (MSC-AEC2s) could improve mortality and alleviate fibrosis in bleomycin-induced PF mice. Transplantation of MSC-AEC2s could increase the AEC2 cell count in these mice, and the results of the cell tracing experiment exhibited that the increased AEC2s originated from the self-renewal of mouse alveolar epithelium. The AEC2 survival was controlled by the apoptosis of AEC2s via the expression of β-catenin in PF mice. In in vitro experiments, MSC-AEC2s could alleviate the apoptosis of MLE-12 cells induced by transforming growth factor beta (TGF-β1), which could be eliminated by using PRI-724, a β-catenin inhibitor, suggesting β-catenin signaling involved in the protection against apoptosis provided by MSC-AEC2s. Our study demonstrated that MSC-AEC2s could protect PF mice through regulating apoptosis mediated by β-catenin, which provided a viable strategy for the treatment of PF.
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Affiliation(s)
- Jiang Liu
- Pediatric Research Institute; Ministry of Education Key Laboratory of Child Development and Disorders; National Clinical Research Center for Child Health and Disorders; China International Science and Technology Cooperation Base of Child Development and Critical Disorders; Chongqing Engineering Research Center of Stem Cell Therapy; Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Danyi Peng
- Department of Respiratory, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Jingyi You
- Pediatric Research Institute; Ministry of Education Key Laboratory of Child Development and Disorders; National Clinical Research Center for Child Health and Disorders; China International Science and Technology Cooperation Base of Child Development and Critical Disorders; Chongqing Engineering Research Center of Stem Cell Therapy; Children's Hospital of Chongqing Medical University, Chongqing, China.,Department of Respiratory, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Ou Zhou
- Pediatric Research Institute; Ministry of Education Key Laboratory of Child Development and Disorders; National Clinical Research Center for Child Health and Disorders; China International Science and Technology Cooperation Base of Child Development and Critical Disorders; Chongqing Engineering Research Center of Stem Cell Therapy; Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Huijun Qiu
- Pediatric Research Institute; Ministry of Education Key Laboratory of Child Development and Disorders; National Clinical Research Center for Child Health and Disorders; China International Science and Technology Cooperation Base of Child Development and Critical Disorders; Chongqing Engineering Research Center of Stem Cell Therapy; Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Chang Hao
- Pediatric Research Institute; Ministry of Education Key Laboratory of Child Development and Disorders; National Clinical Research Center for Child Health and Disorders; China International Science and Technology Cooperation Base of Child Development and Critical Disorders; Chongqing Engineering Research Center of Stem Cell Therapy; Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Hong Chen
- Department of Pediatric, the First Affiliated Hospital of Heilongjiang University of Chinese Medicine, Haerbin, China
| | - Zhou Fu
- Pediatric Research Institute; Ministry of Education Key Laboratory of Child Development and Disorders; National Clinical Research Center for Child Health and Disorders; China International Science and Technology Cooperation Base of Child Development and Critical Disorders; Chongqing Engineering Research Center of Stem Cell Therapy; Children's Hospital of Chongqing Medical University, Chongqing, China.,Department of Respiratory, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Lin Zou
- Pediatric Research Institute; Ministry of Education Key Laboratory of Child Development and Disorders; National Clinical Research Center for Child Health and Disorders; China International Science and Technology Cooperation Base of Child Development and Critical Disorders; Chongqing Engineering Research Center of Stem Cell Therapy; Children's Hospital of Chongqing Medical University, Chongqing, China.,Center of Clinical Molecular Medicine, Children's Hospital of Chongqing Medical University, Chongqing, China.,Clinical Research Unit, Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
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Targeting the crosstalk between canonical Wnt/β-catenin and inflammatory signaling cascades: A novel strategy for cancer prevention and therapy. Pharmacol Ther 2021; 227:107876. [PMID: 33930452 DOI: 10.1016/j.pharmthera.2021.107876] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 04/05/2021] [Indexed: 02/06/2023]
Abstract
Emerging scientific evidence indicates that inflammation is a critical component of tumor promotion and progression. Most cancers originate from sites of chronic irritation, infections and inflammation, underscoring that the tumor microenvironment is largely orchestrated by inflammatory cells and pro-inflammatory molecules. These inflammatory components are intimately involved in neoplastic processes which foster proliferation, survival, invasion, and migration, making inflammation the primary target for cancer prevention and treatment. The influence of inflammation and the immune system on the progression and development of cancer has recently gained immense interest. The Wnt/β-catenin signaling pathway, an evolutionarily conserved signaling strategy, has a critical role in regulating tissue development. It has been implicated as a major player in cancer development and progression with its regulatory role on inflammatory cascades. Many naturally-occurring and small synthetic molecules endowed with inherent anti-inflammatory properties inhibit this aberrant signaling pathway, making them a promising class of compounds in the fight against inflammatory cancers. This article analyzes available scientific evidence and suggests a crosslink between Wnt/β-catenin signaling and inflammatory pathways in inflammatory cancers, especially breast, gastrointestinal, endometrial, and ovarian cancer. We also highlight emerging experimental findings that numerous anti-inflammatory synthetic and natural compounds target the crosslink between Wnt/β-catenin pathway and inflammatory cascades to achieve cancer prevention and intervention. Current challenges, limitations, and future directions of research are also discussed.
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Xia Z, Wu S, Wei X, Liao Y, Yi P, Liu Y, Liu J, Liu J. Hypoxic ER stress suppresses β-catenin expression and promotes cooperation between the transcription factors XBP1 and HIF1α for cell survival. J Biol Chem 2019; 294:13811-13821. [PMID: 31350332 DOI: 10.1074/jbc.ra119.008353] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 07/24/2019] [Indexed: 01/22/2023] Open
Abstract
Hypoxia occurs in many human solid tumors and activates multiple cellular adaptive-response pathways, including the unfolded protein response (UPR) in the endoplasmic reticulum (ER). Wnt/β-catenin signaling plays a critical role in tumorigenesis, and β-catenin has been shown to enhance hypoxia-inducible factor 1α (HIF1α)-activated gene expression, thereby supporting cell survival during hypoxia. However, the molecular interplay between hypoxic ER stress, Wnt/β-catenin signaling, and HIF1α-mediated gene regulation during hypoxia remains incompletely understood. Here, we report that hypoxic ER stress reduces β-catenin stability, which, in turn, enhances the activity of spliced X-box-binding protein 1 (XBP1s), a transcription factor and signal transducer of the UPR, in HIF1α-mediated hypoxic responses. We observed that in the RKO colon cancer cell line, which possesses a Wnt-stimulated β-catenin signaling cascade, increased ER stress during hypoxia is accompanied by a reduction in low-density lipoprotein receptor-related protein 6 (LRP6), and this reduction in LRP6 decreased β-catenin accumulation and impaired Wnt/β-catenin signaling. Of note, β-catenin interacted with both XBP1s and HIF1α, suppressing XBP1s-mediated augmentation of HIF1α target gene expression. Furthermore, Wnt stimulation or β-catenin overexpression blunted XBP1s-mediated cell survival under hypoxia. Together, these results reveal an unanticipated role for the Wnt/β-catenin pathway in hindering hypoxic UPR-mediated responses that increase cell survival. Our findings suggest that the molecular cross-talks between hypoxic ER stress, LRP6/β-catenin signaling, and the HIF1α pathway may represent an unappreciated mechanism that enables some tumor subtypes to survive and grow in hypoxic conditions.
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Affiliation(s)
- Zhixiong Xia
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Shiyong Wu
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Xin Wei
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Yifei Liao
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Ping Yi
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Yong Liu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Jianmiao Liu
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Jianfeng Liu
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
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6
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Kong Q, Gao L, Niu Y, Gongpan P, Xu Y, Li Y, Xiong W. RACK1 is required for adipogenesis. Am J Physiol Cell Physiol 2016; 311:C831-C836. [PMID: 27653985 DOI: 10.1152/ajpcell.00224.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 09/19/2016] [Indexed: 11/22/2022]
Abstract
Adipose tissue plays a critical role in metabolic diseases and the maintenance of energy homeostasis. RACK1 has been identified as an adaptor protein involved in multiple intracellular signal transduction pathways and diseases. However, whether it regulates adipogenesis remains unknown. Here, we reported that RACK1 is expressed in 3T3-L1 cells and murine white adipose tissue and that RACK1 knockdown by shRNA profoundly suppressed adipogenesis by reducing the expression of PPAR-γ and C/EBP-β. Depletion of RACK1 increased β-catenin protein levels and activated Wnt signaling. Furthermore, RACK1 knockdown also suppressed the PI3K-Akt-mTOR-S6K signaling pathway by reducing the PI3K p85α, pAkt T473, and S6K p70. Taken together, these results demonstrate that RACK1 is a novel factor required for adipocyte differentiation by emerging Wnt/β-catenin signaling and PI3K-Akt-mTOR-S6K signaling pathway(s).
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Affiliation(s)
- Qinghua Kong
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Lan Gao
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Graduate University of the Chinese Academy of Sciences, Beijing, China
| | - Yanfen Niu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Biomedical Engineering Research Center, Kunming Medical University, Kunming, China; and
| | - Pianchou Gongpan
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Graduate University of the Chinese Academy of Sciences, Beijing, China
| | - Yuhui Xu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Graduate University of the Chinese Academy of Sciences, Beijing, China
| | - Yan Li
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Yunnan Key Laboratory of Natural Medicinal Chemistry, Kumming, China
| | - Wenyong Xiong
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Yunnan Key Laboratory of Natural Medicinal Chemistry, Kumming, China
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Wang X, Shi SH, Yao HJ, Jing QK, Mo YP, Lv W, Song LY, Yuan XC, Li ZG, Qin LN. Electroacupuncture at Dazhui (GV14) and Mingmen (GV4) protects against spinal cord injury: the role of the Wnt/β-catenin signaling pathway. Neural Regen Res 2016; 11:2004-2011. [PMID: 28197199 PMCID: PMC5270441 DOI: 10.4103/1673-5374.197145] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Electroacupuncture at Dazhui (GV14) and Mingmen (GV4) on the Governor Vessel has been shown to exhibit curative effects on spinal cord injury; however, the underlying mechanism remains poorly understood. In this study, we established rat models of spinal cord injury using a modified Allen's weight-drop method. Ninety-nine male Sprague-Dawley rats were randomly divided into three equal groups: sham (only laminectomy), SCI (induction of spinal cord injury at T10), and EA (induction of spinal cord injury at T10 and electroacupuncture intervention at GV14 and GV4 for 20 minutes once a day). Rats in the SCI and EA groups were further randomly divided into the following subgroups: 1-day (n = 11), 7-day (n = 11), and 14-day (n = 11). At 1, 7, and 14 days after electroacupuncture treatment, the Basso, Beattie and Bresnahan locomotor rating scale showed obvious improvement in rat hind limb locomotor function, hematoxylin-eosin staining showed that the histological change of injured spinal cord tissue was obviously alleviated, and immunohistochemistry and western blot analysis showed that Wnt1, Wnt3a, β-catenin immunoreactivity and protein expression in the injured spinal cord tissue were greatly increased compared with the sham and SCI groups. These findings suggest that electroacupuncture at GV14 and GV4 upregulates Wnt1, Wnt3a, and β-catenin expression in the Wnt/β-catenin signaling pathway, exhibiting neuroprotective effects against spinal cord injury.
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Affiliation(s)
- Xin Wang
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Su-Hua Shi
- Department of Rehabilitation, The Third Affiliated Hospital of Beijing University of Chinese Medicine, Beijing, China
| | - Hai-Jiang Yao
- Treatment Center of Traditional Chinese Medicine, Beijing Bo'ai Hospital, Chinese Rehabilitation Research Center, School of Rehabilitation Medicine, Capital Medical University, Beijing, China
| | - Quan-Kai Jing
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Yu-Ping Mo
- Department of Rehabilitation, The Third People's Hospital of Shenzhen, Shenzhen, Guangdong Province, China
| | - Wei Lv
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Liang-Yu Song
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Xiao-Chen Yuan
- Institute of Microcirculation, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Zhi-Gang Li
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Li-Na Qin
- Department of Rehabilitation, The Third Affiliated Hospital of Beijing University of Chinese Medicine, Beijing, China
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Boonanantanasarn K, Lee HL, Baek K, Woo KM, Ryoo HM, Baek JH, Kim GS. EGF Inhibits Wnt/β-Catenin-Induced Osteoblast Differentiation by Promoting β-Catenin Degradation. J Cell Biochem 2015; 116:2849-57. [DOI: 10.1002/jcb.25231] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 05/14/2015] [Indexed: 11/09/2022]
Affiliation(s)
- Kanitsak Boonanantanasarn
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute; Seoul National University; Seoul Korea
- Departments of Anatomy, Faculty of Dentistry; Mahidol University; Bangkok Thailand
| | - Hye-Lim Lee
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute; Seoul National University; Seoul Korea
- Laboratory of Molecular Signaling, Division of Oral Biology and Medicine; School of Dentistry and Broad Stem Cell Research Center, University of California, Los Angeles; USA
| | - Kyunghwa Baek
- Department of Pharmacology, College of Dentistry; Gangneung-Wonju National University; Gangwondo Korea
| | - Kyung Mi Woo
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute; Seoul National University; Seoul Korea
| | - Hyun-Mo Ryoo
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute; Seoul National University; Seoul Korea
| | - Jeong-Hwa Baek
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute; Seoul National University; Seoul Korea
| | - Gwan-Shik Kim
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute; Seoul National University; Seoul Korea
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Decaffeinated green coffee bean extract attenuates diet-induced obesity and insulin resistance in mice. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 2014:718379. [PMID: 24817902 PMCID: PMC4003760 DOI: 10.1155/2014/718379] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 03/02/2014] [Indexed: 01/22/2023]
Abstract
This study investigated whether decaffeinated green coffee bean extract prevents obesity and improves insulin resistance and elucidated its mechanism of action. Male C57BL/6N mice (N = 48) were divided into six dietary groups: chow diet, HFD, HFD-supplemented with 0.1%, 0.3%, and 0.9% decaffeinated green coffee bean extract, and 0.15% 5-caffeoylquinic acid. Based on the reduction in HFD-induced body weight gain and increments in plasma lipids, glucose, and insulin levels, the minimum effective dose of green coffee bean extract appears to be 0.3%. Green coffee bean extract resulted in downregulation of genes involved in WNT10b- and galanin-mediated adipogenesis and TLR4-mediated proinflammatory pathway and stimulation of GLUT4 translocation to the plasma membrane in white adipose tissue. Taken together, decaffeinated green coffee bean extract appeared to reverse HFD-induced fat accumulation and insulin resistance by downregulating the genes involved in adipogenesis and inflammation in visceral adipose tissue.
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Kong Y, Zhang H, Chen X, Zhang W, Zhao C, Wang N, Wu N, He Y, Nan G, Zhang H, Wen S, Deng F, Liao Z, Wu D, Zhang J, Qin X, Haydon RC, Luu HH, He TC, Zhou L. Destabilization of heterologous proteins mediated by the GSK3β phosphorylation domain of the β-catenin protein. Cell Physiol Biochem 2013; 32:1187-99. [PMID: 24335169 PMCID: PMC4064945 DOI: 10.1159/000354518] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2013] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND AND AIMS Wnt/β-catenin signaling plays important roles in development and cellular processes. The hallmark of canonical Wnt signaling activation is the stabilization of β-catenin protein in cytoplasm and/or nucleus. The stability of β-catenin is the key to its biological functions and is controlled by the phosphorylation of its amino-terminal degradation domain. Aberrant activation of β-catenin signaling has been implicated in the development of human cancers. It has been recently suggested that GSK3βmay play an essential role in regulating global protein turnover. Here, we investigate if the GSK3β phosphorylation site-containing degradation domain of β-catenin is sufficient to destabilize heterologous proteins. METHODS AND RESULTS We engineer chimeric proteins by fusing β-catenin degradation domain at the N- and/or C-termini of the enhanced green fluorescent protein (eGFP). In both transient and stable expression experiments, the chimeric GFP proteins exhibit a significantly decreased stability, which can be effectively antagonized by lithium and Wnt1. An activating mutation in the destruction domain significantly stabilizes the fusion protein. Furthermore, GSK3 inhibitor SB-216763 effectively increases the GFP signal of the fusion protein. Conversely, the inhibition of Wnt signaling with tankyrase inhibitor XAV939 results in a decrease in GFP signal of the fusion proteins, while these small molecules have no significant effects on the mutant destruction domain-GFP fusion protein. CONCLUSION Our findings strongly suggest that the β-catenin degradation domain may be sufficient to destabilize heterologous proteins in Wnt signaling-dependent manner. It is conceivable that the chimeric GFP proteins may be used as a functional reporter to measure the dynamic status of β-catenin signaling, and to identify potential anticancer drugs that target β-catenin signaling.
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Affiliation(s)
- Yuhan Kong
- The First Affiliated Hospital, Chongqing Medical University, Chongqing, China
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Tanjore H, Degryse AL, Crossno PF, Xu XC, McConaha ME, Jones BR, Polosukhin VV, Bryant AJ, Cheng DS, Newcomb DC, McMahon FB, Gleaves LA, Blackwell TS, Lawson WE. β-catenin in the alveolar epithelium protects from lung fibrosis after intratracheal bleomycin. Am J Respir Crit Care Med 2013; 187:630-9. [PMID: 23306543 DOI: 10.1164/rccm.201205-0972oc] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
RATIONALE Alveolar epithelial cells (AECs) play central roles in the response to lung injury and the pathogenesis of pulmonary fibrosis. OBJECTIVES We aimed to determine the role of β-catenin in alveolar epithelium during bleomycin-induced lung fibrosis. METHODS Genetically modified mice were developed to selectively delete β-catenin in AECs and were crossed to cell fate reporter mice that express β-galactosidase (βgal) in cells of AEC lineage. Mice were given intratracheal bleomycin (0.04 units) and assessed for AEC death, inflammation, lung injury, and fibrotic remodeling. Mouse lung epithelial cells (MLE12) with small interfering RNA knockdown of β-catenin underwent evaluation for wound closure, proliferation, and bleomycin-induced cytotoxicity. MEASUREMENTS AND MAIN RESULTS Increased β-catenin expression was noted in lung parenchyma after bleomycin. Mice with selective deletion of β-catenin in AECs had greater AEC death at 1 week after bleomycin, followed by increased numbers of fibroblasts and enhanced lung fibrosis as determined by semiquantitative histological scoring and total collagen content. However, no differences in lung inflammation or protein levels in bronchoalveolar lavage were noted. In vitro, β-catenin-deficient AECs showed increased bleomycin-induced cytotoxicity as well as reduced proliferation and impaired wound closure. Consistent with these findings, mice with AEC β-catenin deficiency showed delayed recovery after bleomycin. CONCLUSIONS β-Catenin in the alveolar epithelium protects against bleomycin-induced fibrosis. Our studies suggest that AEC survival and wound healing are enhanced through β-catenin-dependent mechanisms. Activation of the developmentally important β-catenin pathway in AECs appears to contribute to epithelial repair after epithelial injury.
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Affiliation(s)
- Harikrishna Tanjore
- Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University School of Medicine, 1161 21st Avenue South, Nashville, TN 37232-2650, USA
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Meng M, Zhao XH, Ning Q, Hou L, Xin GH, Liu LF. Tumor stem cells: A new approach for tumor therapy (Review). Oncol Lett 2012; 4:187-193. [PMID: 22844351 DOI: 10.3892/ol.2012.730] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 05/15/2012] [Indexed: 12/29/2022] Open
Abstract
Recent studies have demonstrated the existence of a minority of tumor cells possessing the stem cell properties of self-renewal and differentiation in leukemia and several solid tumors. However, these cells do not possess the normal regulatory mechanisms of stem cells. Following transplantation, they are capable of initiating tumorigenesis and are therefore known as 'tumor stem cells'. Cellular origin analysis of tumor stem cells has resulted in three hypotheses: Embryonal rest hypothesis, anaplasia and maturation arrest. Several signaling pathways which are involved in carcinogenesis, including Wnt/β-catenin, Notch and Oct-4 signaling pathways are crucial in normal stem cell self-renewal decisions, suggesting that breakdown in the regulation of self-renewal may be a key event in the development of tumors. Thus, tumors can be regarded as an abnormal organ in which stem cells have escaped from the normal constraints on self-renewal, thus, leading to abnormally differentiated tumor cells that lose the ability to form tumors. This new model for maligancies has significance for clinical research and treatment.
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Affiliation(s)
- Min Meng
- Department of Oncology, The First Affiliated Hospital of Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
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13
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Li X, Jia Y, Zhang W, Zhang Y, Li B, Huang M, Bao F, Wu J, Lou Y. [The research progress about Wnt pathway of lung cancer stem cells]. ZHONGGUO FEI AI ZA ZHI = CHINESE JOURNAL OF LUNG CANCER 2011; 14:695-8. [PMID: 21859553 PMCID: PMC5999629 DOI: 10.3779/j.issn.1009-3419.2011.08.11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Being the most critical signaling molecule in the Wnt pathway, the Wnt/β-catenin signaling pathway plays an important role in the maintenance of the cell proliferation and clone formation of lung cancer stem cells. Since it is closely related to the WNT pathway, the proliferation of lung cancer stem cells can be restrained by blocking the WNT pathway or influencing its key protein. Such method provides a new method for the treatment of lung cancer. By summarizing the state of-the-art research of lung cancer stem cells and the Wnt pathway from 2005 to 2010, their relationship is investigated.
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Affiliation(s)
- Xiaojiang Li
- Department of Oncology, the First Teaching Hospital, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China
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Wang WD, Melville DB, Montero-Balaguer M, Hatzopoulos AK, Knapik EW. Tfap2a and Foxd3 regulate early steps in the development of the neural crest progenitor population. Dev Biol 2011; 360:173-85. [PMID: 21963426 PMCID: PMC3236700 DOI: 10.1016/j.ydbio.2011.09.019] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 08/24/2011] [Accepted: 09/15/2011] [Indexed: 01/18/2023]
Abstract
The neural crest is a stem cell-like population exclusive to vertebrates that gives rise to many different cell types including chondrocytes, neurons and melanocytes. Arising from the neural plate border at the intersection of Wnt and Bmp signaling pathways, the complexity of neural crest gene regulatory networks has made the earliest steps of induction difficult to elucidate. Here, we report that tfap2a and foxd3 participate in neural crest induction and are necessary and sufficient for this process to proceed. Double mutant tfap2a (mont blanc, mob) and foxd3 (mother superior, mos) mob;mos zebrafish embryos completely lack all neural crest-derived tissues. Moreover, tfap2a and foxd3 are expressed during gastrulation prior to neural crest induction in distinct, complementary, domains; tfap2a is expressed in the ventral non-neural ectoderm and foxd3 in the dorsal mesendoderm and ectoderm. We further show that Bmp signaling is expanded in mob;mos embryos while expression of dkk1, a Wnt signaling inhibitor, is increased and canonical Wnt targets are suppressed. These changes in Bmp and Wnt signaling result in specific perturbations of neural crest induction rather than general defects in neural plate border or dorso-ventral patterning. foxd3 overexpression, on the other hand, enhances the ability of tfap2a to ectopically induce neural crest around the neural plate, overriding the normal neural plate border limit of the early neural crest territory. Although loss of either Tfap2a or Foxd3 alters Bmp and Wnt signaling patterns, only their combined inactivation sufficiently alters these signaling gradients to abort neural crest induction. Collectively, our results indicate that tfap2a and foxd3, in addition to their respective roles in the differentiation of neural crest derivatives, also jointly maintain the balance of Bmp and Wnt signaling in order to delineate the neural crest induction domain.
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Affiliation(s)
- Wen-Der Wang
- Division of Genetic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
| | - David B. Melville
- Division of Genetic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
| | | | - Antonis K. Hatzopoulos
- Division of Cardiovascular Medicine, Department of Medicine and Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
| | - Ela W. Knapik
- Division of Genetic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
- Developmental Biology, Institute Biology I, University of Freiburg, Freiburg, Germany
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15
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16
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Yang GY, Liang B, Zhu J, Luo ZG. Calpain activation by Wingless-type murine mammary tumor virus integration site family, member 5A (Wnt5a) promotes axonal growth. J Biol Chem 2011; 286:6566-76. [PMID: 21177867 PMCID: PMC3057826 DOI: 10.1074/jbc.m110.196568] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 11/29/2010] [Indexed: 11/06/2022] Open
Abstract
Axon development involves spatial-temporal cytoskeletal reorganization. However, how the cytoskeleton remodeling is modulated by extracellular cues is unclear. Here, we report a role of Wnt/Ca(2+) signaling in regulating actin and growth cone dynamics. We found that treatment of cultured cortical neurons with Wnt5a, a non-canonical Wnt, either globally or locally, caused an increase in the activity of calpain, a calcium-dependent protease responsible for the cleavage of several actin binding proteins, including spectrin. Treatment with Wnt5a promoted growth cone advance, as well as axonal growth, and these effects were prevented by chelating intracellular calcium, inhibition or down-regulation of calpain, or blockade of spectrin cleavage by competitive peptides. Interestingly, both Wnt5a and activated calpain were found to be mainly distributed in the axon-rich intermediate zone of neocortex. Down-regulating calpain expression interfered with the growth of callosal axons in vivo. Thus, Wnt5a serves as a physiological cue to stimulate localized calpain activity, which in turn promotes growth cone advance and axonal growth.
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Affiliation(s)
- Guo-Ying Yang
- From the Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Bin Liang
- From the Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Ji Zhu
- From the Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Zhen-Ge Luo
- From the Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
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17
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Jung H, Kim HJ, Lee SK, Kim R, Kopachik W, Han JK, Jho EH. Negative feedback regulation of Wnt signaling by Gbetagamma-mediated reduction of Dishevelled. Exp Mol Med 2010; 41:695-706. [PMID: 19561403 DOI: 10.3858/emm.2009.41.10.076] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Wnt signaling is known to be important for diverse embryonic and post-natal cellular events and be regulated by the proteins Dishevelled and Axin. Although Dishevelled is activated by Wnt and involved in signal transduction, it is not clear how Dishevelled-mediated signaling is turned off. We report that guanine nucleotide binding protein beta 2 (Gnb2; Gbeta2) bound to Axin and Gbeta2 inhibited Wnt mediated reporter activity. The inhibition involved reduction of the level of Dishevelled, and the Gbeta2gamma2 mediated reduction of Dishevelled was countered by increased expression of Axin. Consistent with these effects in HEK293T cells, injection of Gbeta2gamma2 into Xenopus embryos inhibited the formation of secondary axes induced either by XWnt8 or Dishevelled, but not by beta-catenin. The DEP domain of Dishevelled is necessary for both interaction with Gbeta2gamma2 and subsequent degradation of Dishevelled via the lysosomal pathway. Signaling induced by Gbeta2gamma2 is required because a mutant of Gbeta2, Gbeta2 (W332A) with lower signaling activity, had reduced ability to downregulate the level of Dishevelled. Activation of Wnt signaling by either of two methods, increased Frizzled signaling or transient transfection of Wnt, also led to increased degradation of Dishevelled and the induced Dishevelled loss is dependent on Gbeta1 and Gbeta2. Other studies with agents that interfere with PLC action and calcium signaling suggested that loss of Dishevelled is mediated through the following pathway: Wnt/Frizzled-->Gbetagamma-->PLC-->Ca(+2)/PKC signaling. Together the evidence suggests a novel negative feedback mechanism in which Gbeta2gamma2 inhibits Wnt signaling by degradation of Dishevelled.
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Affiliation(s)
- Hwajin Jung
- Department of Life Science, The University of Seoul, Seoul 130-743, Korea
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18
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Abstract
Bone and soft tissue sarcomas are an infrequent and heterogeneous group of mesenchymal tumors including more than a hundred different entities attending to histologic patterns. Research into the molecular aspects of sarcomas has increased greatly in the last few years. This enormous amount of knowledge has allowed, for instance, to refine the classification of sarcomas, improve the diagnosis, and increase the number of therapeutical targets available, most of them under preclinical evaluation. However, other important key issues, such as sarcomagenesis and the cell of origin of sarcomas, remain unresolved. From a molecular point of view, these neoplasias are grouped into 2 main types: (a) sarcomas showing relatively simple karyotypes and translocations, which originate gene fusions (eg, EWS-FLI1 in Ewing sarcoma) or point mutations (eg, c-kit in the gastrointestinal tumors) and (b) sarcomas showing unspecific gene alterations, very complex karyotypes, and no translocations. The discovery of the early mechanisms involved in the genesis of sarcomas, the more relevant signaling pathways, and the development of genetically engineered mouse models could also provide a new individualized therapeutic strategy against these tumors. This review describes the clinical application of some of the molecular alterations found in sarcomas, some advances in the field of sarcomagenesis, and the development of animal models.
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Chen QY, Zhang T, Pincus SH, Wu S, Ricks D, Liu D, Sun Z, Maclaren N, Lan MS. Human CD1D gene expression is regulated by LEF-1 through distal promoter regulatory elements. THE JOURNAL OF IMMUNOLOGY 2010; 184:5047-54. [PMID: 20363964 DOI: 10.4049/jimmunol.0901912] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
CD1d-expressing cells present lipid Ag to CD1d-restricted NKT cells, which play an important role in immune regulation and tumor rejection. Lymphoid enhancer-binding factor-1 (LEF-1) is one of the regulators of the Wnt signaling pathway, which is a powerful regulator in cellular growth, differentiation, and transformation. There is little evidence connecting Wnt signaling to CD1d expression. In this study, we have identified LEF-1 as a regulator of the expression of the gene encoding the human CD1d molecule (CD1D). We found that LEF-1 binds specifically to the CD1D promoter. Overexpression of LEF-1 in K562 or Jurkat cells suppresses CD1D promoter activity and downregulates endogenous CD1D transcripts, whereas knockdown of LEF-1 using LEF-1-specific small interfering RNA increases CD1D transcripts in K562 and Jurkat cells but there are different levels of surface CD1d on these two cell types. Chromatin immunoprecipitation showed that the endogenous LEF-1 is situated at the CD1D promoter and interacts with histone deacetylase-1 to facilitate the transcriptional repressor activity. Knockdown of LEF-1 using small interfering RNA potentiates an acetylation state of histone H3/H4, supporting the notion that LEF-1 acts as a transcriptional repressor for the CD1D gene. Our finding links LEF-1 to CD1D and suggests a role of Wnt signaling in the regulation of the human CD1D gene.
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20
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Milat F, Ng KW. Is Wnt signalling the final common pathway leading to bone formation? Mol Cell Endocrinol 2009; 310:52-62. [PMID: 19524639 DOI: 10.1016/j.mce.2009.06.002] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 06/03/2009] [Accepted: 06/04/2009] [Indexed: 12/17/2022]
Abstract
Since the discovery of the link between mutations in the LRP5 gene and human bone mass, considerable progress has been made in our understanding of Wnt signalling and bone formation. The connection between canonical Wnt signalling and bone formation is convincing, and there is evidence of interaction between the Wnt signalling pathway and key growth factors, transcriptional factors and systemic hormones. More recently, the role of the non-canonical pathway in bone metabolism has also started to be explored as well as potential bone-gut interactions. This review focuses on the role of the Wnt pathway in osteoblast differentiation as well as the interplay between Wnt signalling and other pathways involved in bone formation.
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Affiliation(s)
- Frances Milat
- St Vincent's Institute, Fitzroy, Victoria 3065, Australia.
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21
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Zhang T, Bai YZ, Wang DJ, Jia HM, Yuan ZW, Wang WL. Spatiotemporal pattern analysis of transcription factor 4 in the developing anorectum of the rat embryo with anorectal malformations. Int J Colorectal Dis 2009; 24:1039-47. [PMID: 19387659 DOI: 10.1007/s00384-009-0705-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/01/2009] [Indexed: 02/04/2023]
Abstract
PURPOSE As a member of the transcription factors family, transcription factor 4(Tcf4) is known to influence gene expression in endodermally derived tissues including lung, liver, pancreas, stomach, and intestine. However, it remained unknown if this capability is active during anorectal development in the normal and anorectal malformations (ARM) rat embryos. MATERIALS AND METHODS In this study, ethylenethiourea (ETU)-induced ARM model was introduced to investigate the expression pattern of Tcf4 during anorectal development using immunohistochemical staining, reverse transcriptase polymerase chain reaction (RT-PCR), and Western blot analysis. RESULTS Immunostaining revealed that Tcf4 expression showed space-dependent changes in the developing anorectum: in normal embryos, Tcf4 protein is initially expressed in the dorsal endoderm of urorectal septum (URS) and hindgut on embryonic day 13 (E13). Additionally, separate expression domain develops intensively on the dorsal CM on E14. On E15, positive cells are then detected in the fused tissue of URS, and prominently in the anal membrane. In the ARM embryos, however, the epithelium of the cloaca, URS, and anorectum was negative or faint for Tcf4. In Western blot and RT-PCR, time-dependent changes of Tcf4 protein and mRNA expression were remarkable during the anorectal development: on E14, E14.5, and E15, the expression level reached the peak; after E16, Tcf4 expression gradually decreased. In contrast, in ARM embryos, spatiotemporal expression of Tcf4 was imbalanced during the anorectal morphogenesis from E13 to E16. CONCLUSIONS These data implied that the downregulation of Tcf4 at the time of cloacal separation into rectum and urethra might be related to the development of ARM.
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Affiliation(s)
- Tao Zhang
- Department of Pediatric Surgery, Shengjing Hospital China Medical University, Heping District, Shenyang 110004, People's Republic of China
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22
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Expression, purification and functional characterization of Wnt signaling co-receptors LRP5 and LRP6. Protein Expr Purif 2009; 70:39-47. [PMID: 19716419 DOI: 10.1016/j.pep.2009.08.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 08/21/2009] [Accepted: 08/24/2009] [Indexed: 11/21/2022]
Abstract
Activation of the Wnt signaling cascade plays a pivotal role during development and in various disease states. Wnt signals are transduced by seven-transmembrane Frizzled (Fz) proteins and the single-transmembrane LDL-receptor-related proteins 5 or 6 (LRP5/6). Genetic mutations resulting in a loss or gain of function of LRP5 in humans lead to osteopenia and bone formation, respectively. These findings demonstrate the genetic link between LRP5 signaling and the regeneration of bone mass. Herein we describe for the first time the production and characterization of soluble ectodomains of LRP5 and LRP6, (EC-LRP5, EC-LRP6). We have produced these proteins in amounts that are compatible with both in vitro and cell-based assays to study their binding properties. Purified EC-LRP5 and EC-LRP6 were able to interact with Wnt signaling components Dkk1 and Dkk2 and their functionality was confirmed in cell-based Wnt signaling assays. Hence, tools are now available to explore LRP5/6 interaction with other proteins and to screen for synthetic or natural compounds and biologics that might be novel therapeutics targeting the Wnt pathway.
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23
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CUX1/Wnt signaling regulates epithelial mesenchymal transition in EBV infected epithelial cells. Exp Cell Res 2009; 315:1819-31. [PMID: 19361498 DOI: 10.1016/j.yexcr.2009.04.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 03/06/2009] [Accepted: 04/02/2009] [Indexed: 02/07/2023]
Abstract
Idiopathic pulmonary fibrosis (IPF) is a refractory and lethal interstitial lung disease characterized by alveolar epithelial cells apoptosis, fibroblast proliferation and extra-cellular matrix protein deposition. EBV, localised to alveolar epithelial cells of pulmonary fibrosis patients is associated with a poor prognosis. A strategy based on microarray-differential gene expression analysis to identify molecular drivers of EBV-associated lung fibrosis was utilized. Alveolar epithelial cells were infected with EBV to identify genes whose expression was altered following TGFbeta1-mediated lytic phase. EBV lytic reactivation by TGFbeta1 drives a selective alteration in CUX1 variant (a) (NCBI accession number NM_181552) expression, inducing activation of non-canonical Wnt pathway mediators, implicating it in Epithelial Mesenchymal Transition (EMT), the molecular event underpinning scar production in tissue fibrosis. The role of EBV in EMT can be attenuated by antiviral strategies and inhibition of Wnt signaling by using All-Trans Retinoic Acids (ATRA). Activation of non-canonical Wnt signaling pathway by EBV in epithelial cells suggests a novel mechanism of EMT via CUX1 signaling. These data present a framework for further description of the link between infectious agents and fibrosis, a significant disease burden.
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COUP-TFII acts downstream of Wnt/beta-catenin signal to silence PPARgamma gene expression and repress adipogenesis. Proc Natl Acad Sci U S A 2009; 106:5819-24. [PMID: 19307559 DOI: 10.1073/pnas.0901676106] [Citation(s) in RCA: 143] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Wnt signaling through beta-catenin and TCF maintains preadipocytes in an un-differentiated proliferative state; however, the molecular pathway has not been completely defined. By integrating gene expression microarray, chromatin immunoprecipitation-chip, and cell-based experimental approaches, we show that Wnt/beta-catenin signaling activates the expression of COUP-TFII which recruits the SMRT corepressor complex to the first introns located downstream from the first exons of both PPARgamma1 and gamma2 mRNAs. This maintains the local chromatin in a hypoacetylated state and represses PPARgamma gene expression to inhibit adipogenesis. Our experiments define the COUP-TFII/SMRT complex as a previously unappreciated component of the linear pathway that directly links Wnt/beta-catenin signaling to repression of PPARgamma gene expression and the inhibition of adipogenesis.
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25
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COUP-TFII acts downstream of Wnt/beta-catenin signal to silence PPARgamma gene expression and repress adipogenesis. Proc Natl Acad Sci U S A 2009. [PMID: 19307559 DOI: 10.1073/pnas.090167610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Wnt signaling through beta-catenin and TCF maintains preadipocytes in an un-differentiated proliferative state; however, the molecular pathway has not been completely defined. By integrating gene expression microarray, chromatin immunoprecipitation-chip, and cell-based experimental approaches, we show that Wnt/beta-catenin signaling activates the expression of COUP-TFII which recruits the SMRT corepressor complex to the first introns located downstream from the first exons of both PPARgamma1 and gamma2 mRNAs. This maintains the local chromatin in a hypoacetylated state and represses PPARgamma gene expression to inhibit adipogenesis. Our experiments define the COUP-TFII/SMRT complex as a previously unappreciated component of the linear pathway that directly links Wnt/beta-catenin signaling to repression of PPARgamma gene expression and the inhibition of adipogenesis.
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26
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Activin A-Induced Differentiation of Embryonic Stem Cells into Endoderm and Pancreatic Progenitors—The Influence of Differentiation Factors and Culture Conditions. Stem Cell Rev Rep 2009; 5:159-73. [DOI: 10.1007/s12015-009-9061-5] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Accepted: 02/19/2009] [Indexed: 02/07/2023]
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Co-opted JNK/SAPK signaling in Wnt/beta-catenin-induced tumorigenesis. Neoplasia 2009; 10:1004-13. [PMID: 18714362 DOI: 10.1593/neo.08548] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 06/19/2008] [Accepted: 06/23/2008] [Indexed: 11/18/2022]
Abstract
Aberrant stimulation of the canonical Wnt pathway induces mammary tumorigenesis in mice. It has been well documented that two types of tumors, adenocarcinoma and adenocarcinoma with squamous metaplasia, develop in these mutants. However, the molecular mechanism underlying the induction of squamous transdifferentiation remains largely unknown. Here, we show that JNK/SAPK signaling plays an important role in Wnt-dependent mammary development and malignant transformation. The JNK/SAPK pathway is stimulated in pregnancy-mediated lobulo-alveolar morphogenesis, a process highly dependent on Wnt/beta-catenin signaling. Strong elevations of JNK/SAPK signaling are associated with squamous metaplasia of the Wnt-induced adenocarcinoma. Reconstitution of beta-catenin and JNK/SAPK signaling activities also promotes expression of the squamous cell marker in cultured epithelial cells. Furthermore, a synergistic activation of these two pathways can be identified in the malignant squamous cells of human endometrial and lung cancers. This is potentially a significant discovery in modern cancer therapy because of the effectiveness of an angiogenesis inhibitor, Avastin, for the treatment of adenocarcinoma, but not squamous cell carcinoma, in human lung cancers. Our finding may improve the usage of biomarkers to distinguish these two poorly differentiated tumor types, sharing similar histologic features.
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Stabilized beta-catenin functions through TCF/LEF proteins and the Notch/RBP-Jkappa complex to promote proliferation and suppress differentiation of neural precursor cells. Mol Cell Biol 2008; 28:7427-41. [PMID: 18852283 DOI: 10.1128/mcb.01962-07] [Citation(s) in RCA: 150] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The proliferation and differentiation of neural precursor cells are mutually exclusive during brain development. Despite its importance for precursor cell self renewal, the molecular linkage between these two events has remained unclear. Fibroblast growth factor 2 (FGF2) promotes neural precursor cell proliferation and concurrently inhibits their differentiation, suggesting a cross talk between proliferation and differentiation signaling pathways downstream of the FGF receptor. We demonstrate that FGF2 signaling through phosphatidylinositol 3 kinase activation inactivates glycogen synthase kinase 3beta (GSK3beta) and leads to the accumulation of beta-catenin in a manner different from that in the Wnt canonical pathway. The nuclear accumulated beta-catenin leads to cell proliferation by activating LEF/TCF transcription factors and concurrently inhibits neuronal differentiation by potentiating the Notch1-RBP-Jkappa signaling pathway. beta-Catenin and the Notch1 intracellular domain form a molecular complex with the promoter region of the antineurogenic hes1 gene, allowing its expression. This signaling interplay is especially essential for neural stem cell maintenance, since the misexpression of dominant-active GSK3beta completely inhibits the self renewal of neurosphere-forming stem cells and prompts their neuronal differentiation. Thus, the GSK3beta/beta-catenin signaling axis regulated by FGF and Wnt signals plays a pivotal role in the maintenance of neural stem/precursor cells by linking the cell proliferation to the inhibition of differentiation.
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29
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Morello R, Bertin TK, Schlaubitz S, Shaw CA, Kakuru S, Munivez E, Hermanns P, Chen Y, Zabel B, Lee B. Brachy-syndactyly caused by loss of Sfrp2 function. J Cell Physiol 2008; 217:127-37. [PMID: 18446812 DOI: 10.1002/jcp.21483] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Wnt signaling pathways are regulated both at the intracellular and extracellular levels. During embryogenesis, the in vivo effects of the secreted frizzled-related protein (Sfrp) family of Wnt inhibitors are poorly understood. Here, we show that inactivation of Sfrp2 results in subtle limb defects in mice with mesomelic shortening and consistent shortening of all autopodal elements that is clinically manifested as brachydactyly. In addition, there is soft-tissue syndactyly of the hindlimb. The brachydactyly is caused by decreased chondrocyte proliferation and delayed differentiation in distal limb chondrogenic elements. These data suggest that Sfrp2 can regulate both chondrogenesis and regression of interdigital mesenchyme in distal limb. Sfrp2 can also repress canonical Wnt signaling by Wnt1, Wnt9a, and Wnt4 in vitro. Sfrp2-/- and TOPGAL/Sfrp2-/- mice have a mild increase in beta-catenin and beta-galactosidase staining, respectively, in some phalangeal elements. This however does not exclude a potential concurrent effect on non-canonical Wnt signaling in the growth plate. In combination with what is known about BMP and Wnt signaling in human brachydactylies, our data establish a critical role for Sfrp2 in proper distal limb formation and suggest SFPR2 could be a novel candidate gene for human brachy-syndactyly defects.
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Affiliation(s)
- Roy Morello
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA.
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30
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Voronkov AE, Baskin II, Palyulin VA, Zefirov NS. Molecular model of the Wnt protein binding site on the surface of dimeric CRD domain of the hFzd8 receptor. DOKL BIOCHEM BIOPHYS 2008; 419:75-8. [PMID: 18505162 DOI: 10.1134/s1607672908020087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- A E Voronkov
- Lomonosov Moscow State University, Moscow, 119991 Russia
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31
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Jin T, Liu L. The Wnt signaling pathway effector TCF7L2 and type 2 diabetes mellitus. Mol Endocrinol 2008; 22:2383-92. [PMID: 18599616 DOI: 10.1210/me.2008-0135] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Since the relationship between TCF7L2 (also known as TCF-4) polymorphisms and type 2 diabetes mellitus was identified in 2006, extensive genome-wide association examinations in different ethnic groups have further confirmed this relationship. As a component of the bipartite transcription factor beta-catenin/TCF, TCF7L2 is important in conveying Wnt signaling during embryonic development and in regulating gene expression during adulthood. Although we still do not know mechanistically how the polymorphisms within the intron regions of TCF7L2 affect the risk of type 2 diabetes, this transcriptional regulator was shown to be involved in stimulating the proliferation of pancreatic beta-cells and the production of the incretin hormone glucagon-like peptide-1 in intestinal endocrine L cells. In this review, we introduce background knowledge of TCF7L2 as a component of the Wnt signaling pathway, summarize recent findings demonstrating the association between TCF7L2 polymorphisms and the risk of type 2 diabetes, outline experimental evidence of the potential function of TCF7L2 in pancreatic and intestinal endocrine cells, and present our perspective views.
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Affiliation(s)
- Tianru Jin
- Department of Medicine, Physiology, and Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.
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Voronkov AE, Baskin II, Palyulin VA, Zefirov NS. Molecular modeling of the complex between the xWNT8 protein and the CRD domain of the mFZD8 receptor. DOKL BIOCHEM BIOPHYS 2008; 412:8-11. [PMID: 17506343 DOI: 10.1134/s1607672907010036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- A E Voronkov
- Department of Chemistry, Moscow State University, Vorob'evy gory, Moscow 119992, Russia
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Ivanova L, Butt MJ, Matsell DG. Mesenchymal transition in kidney collecting duct epithelial cells. Am J Physiol Renal Physiol 2008; 294:F1238-48. [PMID: 18322023 DOI: 10.1152/ajprenal.00326.2007] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Progressive organ damage due to tissue scarring and fibrosis is a paradigm shared by numerous human diseases including chronic kidney disease. The purpose of this study was to confirm the hypothesis that collecting duct (CD) epithelial cells can undergo mesenchymal transition (EMT) in vitro. The mechanism by which CDs undergo EMT is complex and involves both early and late cellular events. Early events include rapid insulin-like growth factor (IGF)-induced Akt and GSK-3beta phosphorylation, associated with early disruption of E-cadherin-beta-catenin membrane colocalization, with translocation of E-cadherin to endosomes, with translocation of beta-catenin to the nucleus, and with an increase in Snail expression. Transforming growth factor-beta1, on the other hand, induced early activation of Smad3 and its translocation to the nucleus, Erk1/2 phosphorylation, and early disruption of membrane E-cadherin localization. The late consequences of these events included a phenotypic transformation of the cells to a mesenchymal morphology with associated increase in vimentin and alpha-smooth muscle actin protein expression and a decrease in total cellular E-cadherin expression, detectable as early as 24 h after stimulation.
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Affiliation(s)
- Larissa Ivanova
- Department of Pediatrics and Child and Family Research Institute, British Columbia Children's Hospital, Vancouver, British Columbia, Canada
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Lavery DL, Davenport IR, Turnbull YD, Wheeler GN, Hoppler S. Wnt6 expression in epidermis and epithelial tissues duringXenopusorganogenesis. Dev Dyn 2008; 237:768-79. [DOI: 10.1002/dvdy.21440] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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35
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Voronkov AE, Baskin II, Palyulin VA, Zefirov NS. Molecular modeling of modified peptides, potent inhibitors of the xWNT8 and hWNT8 proteins. J Mol Graph Model 2008; 26:1179-87. [PMID: 18296089 DOI: 10.1016/j.jmgm.2007.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Revised: 10/26/2007] [Accepted: 10/26/2007] [Indexed: 11/30/2022]
Abstract
Signaling pathways of Wnt-proteins and Fzd-receptors play important role in processes of growth and development of stem cells and in many types of cancers. The binding of the Wnt-proteins and Fzd-receptors is a complicated process, in which 19 Wnt-proteins and 10 Fzd-receptors are involved. Such a large number of combinations of Wnt-Fzd pairs leads to many different influences of Fzd-Wnt-complexes on the development and differentiation of stem cells. The molecular models of xWnt8, hWnt8, mFzd8, hFzd8-proteins and their complexes were constructed and studied in the present work. The amino acids of the binding sites of proteins which participate in these complexes formation and the protein-protein interactions were studied. The pharmacophoric model of the binding site on the xWnt8 and hWnt8-proteins was constructed. In this work we suggested the peptidomimetic ligands, which can be used for the inhibition of the xWnt8-mFzd8 and hWnt8-hFzd8 proteins formation. The de novo design method of Allegrow software was used for the predictions of most prospective functional groups of the peptidomimetic ligands. These ligands can be used as inhibitors of xWnt8-mFzd8 and hWnt8-hFzd8 complex formation and also can be used for drug design by other methods.
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Affiliation(s)
- A E Voronkov
- Department of Chemistry, M.V. Lomonosov Moscow State University, 119992 Moscow, Russian Federation.
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36
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Wnt-10b, uniquely among Wnts, promotes epithelial differentiation and shaft growth. Biochem Biophys Res Commun 2007; 367:299-304. [PMID: 18155657 DOI: 10.1016/j.bbrc.2007.12.091] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Accepted: 12/13/2007] [Indexed: 11/22/2022]
Abstract
Although Wnts are expressed in hair follicles throughout life from embryo to adult, and considered to be critical for their development and maturation, their roles remain largely unknown. In the present study, we investigated the effects of Wnts (Wnt-3a, Wnt-5a, Wnt-10b, and Wnt-11) on epithelial cell differentiation using adult mouse-derived primary skin epithelial cell (MPSEC) cultures and hair growth using hair follicle organ cultures. Only Wnt-10b showed evident promotion of epithelial cell differentiation and hair shaft growth, in contrast to Wnt-3a, 5a, and 11. Our results suggest that Wnt-10b is unique and plays an important role in differentiation of epithelial cells in the hair follicle.
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37
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Ziegler S, Röhrs S, Tickenbrock L, Langerak A, Chu ST, Feldmann I, Jakubowski N, Müller O. Lipocalin 24p3 is regulated by the Wnt pathway independent of regulation by iron. ACTA ACUST UNITED AC 2007; 174:16-23. [PMID: 17350462 DOI: 10.1016/j.cancergencyto.2006.11.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Revised: 10/27/2006] [Accepted: 11/03/2006] [Indexed: 11/25/2022]
Abstract
Lipocalin 24p3 plays a direct role in iron transport and regulates the levels of important proteins of the iron metabolism. Iron-loaded 24p3 binds to its specific receptor (24p3R) on the cell surface. Upon binding to its receptor, 24p3 is internalized into the cell, where it releases its bound iron. Iron-free 24p3 can withdraw iron from inside the cell to the outside by a reverse mechanism. We analyzed the role of the murine 24p3 gene Lcn2 (alias 24p3) as a target of the Wnt pathway. In cells with activated Wnt pathway, the levels of 24p3 protein and RNA were decreased. The withdrawal of iron led to 24p3 downregulation, and iron addition to iron-deprived cells induced 24p3 expression. Despite its strong inhibitory effect on 24p3 expression, Wnt pathway activation had no effect on the intracellular iron level. In cells with nonactivated Wnt pathway, we found an as yet unidentified transcript of 24p3R. Our results indicate independent regulation of 24p3 expression by the Wnt pathway and by the intracellular iron level. Differential splicing of the 24p3R transcript, depending on the activation state of the Wnt pathway, may modify the function of 24p3.
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Affiliation(s)
- Slava Ziegler
- Max-Planck-Institut für molekulare Physiologie, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
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Wang H, Gilner JB, Bautch VL, Wang DZ, Wainwright BJ, Kirby SL, Patterson C. Wnt2 coordinates the commitment of mesoderm to hematopoietic, endothelial, and cardiac lineages in embryoid bodies. J Biol Chem 2006; 282:782-91. [PMID: 17098737 DOI: 10.1074/jbc.m606610200] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Our recent gene expression profiling analyses demonstrated that Wnt2 is highly expressed in Flk1(+) cells, which serve as common progenitors of endothelial cells, blood cells, and mural cells. In this report, we characterize the role of Wnt2 in mesoderm development during embryonic stem (ES) cell differentiation by creating ES cell lines in which Wnt2 was deleted. Wnt2(-/-) embryoid bodies (EBs) generated increased numbers of Flk1(+) cells and blast colony-forming cells compared with wild-type EBs, and had higher Flk1 expression at comparable stages of differentiation. Although Flk1(+) cells were increased, we found that endothelial cell and terminal cardiomyocyte differentiation was impaired, but hematopoietic cell differentiation was enhanced and smooth muscle cell differentiation was unchanged in Wnt2(-/-) EBs. Later stage Wnt2(-/-) EBs had either lower or undetectable expression of endothelial and cardiac genes compared with wild-type EBs. Consistently, vascular plexi were poorly formed and neither beating cardiomyocytes nor alpha-actinin-staining cells were detectable in later stage Wnt2(-/-) EBs. In contrast, hematopoietic cell gene expression was upregulated, and the number of hematopoietic progenitor colonies was significantly enhanced in Wnt2(-/-) EBs. Our data indicate that Wnt2 functions at multiple stages of development during ES cell differentiation and during the commitment and diversification of mesoderm: as a negative regulator for hemangioblast differentiation and hematopoiesis but alternatively as a positive regulator for endothelial and terminal cardiomyocyte differentiation.
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Affiliation(s)
- Hong Wang
- Carolina Cardiovascular Biology Center and Department of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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39
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Heeg-Truesdell E, LaBonne C. Neural induction in Xenopus requires inhibition of Wnt-β-catenin signaling. Dev Biol 2006; 298:71-86. [PMID: 16879817 DOI: 10.1016/j.ydbio.2006.06.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2006] [Revised: 06/05/2006] [Accepted: 06/06/2006] [Indexed: 12/22/2022]
Abstract
Canonical Wnt signals have been implicated in multiple events during early embryogenesis, including primary axis formation, neural crest induction, and A-P patterning of the neural plate. The mechanisms by which Wnt signals can direct distinct fates in cell types that are closely linked both temporally and spatially remains poorly understood. However, recent work has suggested that the downstream transcriptional mediators of this pathway, Lef/Tcf family DNA binding proteins, may confer distinct outcomes on these signals in some cellular contexts. In this study, we first examined whether inhibitory mutants of XTcf3 and XLef1 might block distinct Wnt-dependent signaling events during the diversification of cell fates in the early embryonic ectoderm. We found that a Wnt-unresponsive mutant of XTcf3 potently blocks neural crest formation, whereas an analogous mutant of XLef1 does not, and that the difference in activity mapped to the C-terminus of the proteins. Significantly, the inhibitory XTcf3 mutant also blocked expression of markers of anterior-most cell types, including cement gland and sensory placodes, indicating that Wnt signals are required for rostral as well as caudal ectodermal fates. Unexpectedly, we also found that blocking canonical Wnt signals in the ectoderm, using the inhibitory XTcf3 mutant or by other means, dramatically expanded the size of the neural plate, as evidenced by the increased expression of early pan-neural markers such as Sox3 and Nrp1. Conversely, we find that upregulation of canonical Wnt signals interferes with the induction of the neural plate, and this activity can be separated experimentally from Wnt-mediated neural crest induction. Together these findings provide important and novel insights into the role of canonical Wnt signals during the patterning of vertebrate ectoderm and indicate that Wnt inhibition plays a central role in the process of neural induction.
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Affiliation(s)
- Elizabeth Heeg-Truesdell
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Il 60208, USA
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Liu J, Wu X, Mitchell B, Kintner C, Ding S, Schultz PG. A small-molecule agonist of the Wnt signaling pathway. Angew Chem Int Ed Engl 2006; 44:1987-90. [PMID: 15724259 DOI: 10.1002/anie.200462552] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jun Liu
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, SR202, La Jolla, CA 92037, USA
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Tu HP, Chen YT, Shieh YS, Chin YT, Huang RY, Yang SF, Gau CH, Fu E. Cyclosporin-induced downregulation of the expression of E-cadherin during proliferation of edentulous gingival epithelium in rats. J Periodontol 2006; 77:832-9. [PMID: 16671876 DOI: 10.1902/jop.2006.050316] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND To examine the role of E-cadherin in epithelial hyperplasia of cyclosporin A (CsA)-induced gingival enlargement, mRNA and protein levels of E-cadherin, beta-catenin, proliferating cell nuclear antigen (PCNA), and Cyclin D1 were examined in the edentulous gingiva of rats following CsA treatment. METHODS Three weeks after the extraction of all maxillary molars, 20 male Sprague-Dawley rats were assigned to a CsA-fed group (30 mg/kg daily) or a control group. Five rats per group were sacrificed at weeks 1 and 4. Edentulous ridge specimens were taken, and the expression levels of E-cadherin, beta-catenin, Cyclin D1, and PCNA mRNAs were estimated by reverse transcription-polymerase chain reaction (RT-PCR). Tissue specimens of the week 4 groups were examined using immunohistochemical (IHC) staining for proteins. RESULTS The mRNA expression of E-cadherin was significantly weaker in the CsA-treated group than the control group at both times. Using IHC staining, a weaker level of membrane-bonded E-cadherin was also observed in the gingival epithelial cells in the CsA group than in controls. By contrast, significantly stronger beta-catenin and Cyclin D1 mRNA expressions and protein levels were found in CsA-treated rats than controls by RT-PCR and immunohistochemistry at week 4, whereas PCNA production was stronger at both times. CONCLUSIONS CsA treatment reduced the production of E-cadherin but increased the production of beta-catenin, Cyclin D1, and PCNA. Thus, CsA may downregulate E-cadherin gene expression, leading to the epithelial cell proliferation of gingival overgrowth.
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Affiliation(s)
- Hsiao-Pei Tu
- Institute of Oral Biology, National Yang-Ming University, Taipei, Taiwan, Republic of China
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Hao J, Li TG, Qi X, Zhao DF, Zhao GQ. WNT/beta-catenin pathway up-regulates Stat3 and converges on LIF to prevent differentiation of mouse embryonic stem cells. Dev Biol 2005; 290:81-91. [PMID: 16330017 DOI: 10.1016/j.ydbio.2005.11.011] [Citation(s) in RCA: 215] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Revised: 10/26/2005] [Accepted: 11/08/2005] [Indexed: 11/26/2022]
Abstract
Embryonic stem (ES) cells rely on growth factors provided by feeder cells or exogenously to maintain their pluripotency. In order to identify such factors, we have established sub-lines of STO feeder cells which exhibit variable ability in supporting ES cell self-renewal. Functional screening identifies WNT5A and WNT6 as STO cell-produced factors that potently inhibit ES cell differentiation in a serum-dependent manner. Furthermore, direct activation of beta-catenin without disturbing the upstream components of the WNT/beta-catenin pathway fully recapitulates the effect of WNTs on ES cells. Importantly, the WNT/beta-catenin pathway up-regulates the mRNA for Stat3, a known regulator of ES cell self-renewal in the mouse. Finally, LIF is able to mimic the serum effect to act synergistically with WNT proteins to inhibit ES cell differentiation. Therefore, our study reveals part of the molecular mechanisms by which the WNT/beta-catenin pathway acts to prevent ES cell differentiation through convergence on the LIF/JAK-STAT pathway at the level of STAT3.
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Affiliation(s)
- Jing Hao
- Cecil H. and Ida Green Center for Reproductive Biology Sciences, Department of Pharmacology, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, 75390-9051, USA
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Abstract
The intestinal epithelium is a self-renewing tissue which represents a unique model for studying interconnected cellular processes such as proliferation, differentiation, cell migration and carcinogenesis. Although the stem cells of the intestine have not yet been physically characterized or isolated, data over the past decade have strongly implicated the Wnt/beta-catenin signalling pathway in their maintenance and progression to cancer. This review will (i) describe the distinctive features of the intestinal epithelium in relation to stem-cell function, (ii) illustrate the major genetic alterations that can lead to cancer, and (iii) show how Wnt/beta-catenin signalling controls homoeostasis in this tissue.
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Affiliation(s)
- Daniel Pinto
- Hubrecht Laboratory, Netherlands Institute for Developmental Biology, 3584 CT Utrecht, The Netherlands
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44
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Liu J, Wu X, Mitchell B, Kintner C, Ding S, Schultz PG. A Small-Molecule Agonist of the Wnt Signaling Pathway. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200462552] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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45
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Abstract
The phosphoprotein Dishevelled (Dsh) is an essential component of Wnt signaling pathways and transduces signals into three separate branches, the canonical, non-canonical and Ca2+ pathways. How Dsh focuses signaling into these branches remains mysterious, but a new study reveals the importance of nuclear localization of Dsh for pathway-specific activation.
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Affiliation(s)
- Raymond Habas
- Cancer Institute of New Jersey and Department of Biochemistry, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - Igor B Dawid
- Laboratory of Molecular Genetics, National Institutes of Child Health and Human Development, Bethesda, MD 20892-2790, USA
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Wang J, Wynshaw-Boris A. The canonical Wnt pathway in early mammalian embryogenesis and stem cell maintenance/differentiation. Curr Opin Genet Dev 2005; 14:533-9. [PMID: 15380245 DOI: 10.1016/j.gde.2004.07.013] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The Wnt signaling pathway plays essential roles in embryogenesis of higher eukaryotes from diploblastic, radially symmetrical cnidarians to mice and humans. Whereas studies in model organisms such as Drosophila and Xenopus continue to elucidate how the Wnt pathway is regulated, studies of mouse mutants and cultured mammalian cells start to reveal how the Wnt pathway controls development and differentiation in mammals. Here we review some of the recent progresses in our understanding of the Wnt pathway. We focus on how this pathway, through regulating transcription of its downstream target genes, specifies pattern formation during mammalian embryogenesis and functions in the differentiation and maintenance of stem cells both in vivo and in vitro.
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Affiliation(s)
- Jianbo Wang
- Department of Pediatrics, School of Medicine, University of California, San Diego, 9500 Gilman Dr., MC 0627, La Jolla, California 92093-0627, USA
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Kim TH, Xiong H, Zhang Z, Ren B. beta-Catenin activates the growth factor endothelin-1 in colon cancer cells. Oncogene 2005; 24:597-604. [PMID: 15558022 DOI: 10.1038/sj.onc.1208237] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Endothelin-1 (EDN1) is a growth factor that is frequently produced by cancer cells and plays a critical role in tumorigenesis. However, the molecular mechanism controlling the expression of EDN1 in cancers is unknown. Constitutive activation of beta-catenin pathway is responsible for the initiation of the vast majority of colon cancers. Here we show that the EDN1 gene is directly regulated by beta-catenin in colon cancer cells. A specific DNA element within the EDN1 promoter is required for activation, and is associated with beta-catenin's cognate DNA binding partner, TCF4, in vivo. Inhibition of beta-catenin signaling results in lowered expression of EDN1, while enhancement of beta-catenin signaling leads to further activation of the gene. Significantly elevated EDN1 expression occurs in 80% of primary human colon cancers, consistent with it being a direct target of beta-catenin. Furthermore, EDN1 is able to rescue colon cancer cells from growth arrest and apoptosis resulting from inhibition of beta-catenin signaling, implicating a key role of EDN1 in promoting the oncogenic function of beta-catenin. These results indicate EDN1 overexpression as a major cause in colon cancers and reveal further details of the genetic programs responsible for tumorigenesis of colon cancers.
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Affiliation(s)
- Tae Hoon Kim
- Laboratory of Gene Regulation, Ludwig Institute for Cancer Research, UCSD School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093, USA
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Liu J, Bang AG, Kintner C, Orth AP, Chanda SK, Ding S, Schultz PG. Identification of the Wnt signaling activator leucine-rich repeat in Flightless interaction protein 2 by a genome-wide functional analysis. Proc Natl Acad Sci U S A 2005; 102:1927-32. [PMID: 15677333 PMCID: PMC548559 DOI: 10.1073/pnas.0409472102] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Wnt signaling pathway acts ubiquitously in metazoans to control various aspects of embryonic development. Wnt ligands bind their receptors Frizzled and low-density lipoprotein receptor-related protein 5/6 and function through Disheveled (Dvl), Axin, adenomatous polyposis coli, glycogen synthase kinase 3beta, and casein kinase (CK) 1 to stabilize beta-catenin and induce lymphocyte enhancer-binding factor (LEF)/T cell factor (TCF)-dependent transcriptional activities. To identify previously unrecognized Wnt signaling modulators, a genome-wide functional screen was performed using large-scale arrayed cDNA collections. From this screen, both known components and previously uncharacterized regulators of this pathway were identified, including beta-catenin, Dvl1, Dvl3, Fbxw-1, Cul1, CK1epsilon, CK1delta, and gamma-catenin. In particular, a previously unrecognized activator, LRRFIP2 (leucine-rich repeat in Flightless interaction protein 2), was found that interacts with Dvl to increase the cellular levels of beta-catenin and activate beta-catenin/LEF/TCF-dependent transcriptional activity. The function of LRRFIP2 is blocked when a dominant negative Dvl (Xdd1) is coexpressed. Expression of LRRFIP2 in Xenopus embryos induced double axis formation and Wnt target gene expression; a dominant negative form of LRRFIP2 suppresses ectopic Wnt signaling in Xenopus embryos and partially inhibits endogenous dorsal axis formation. These data suggest that LRRFIP2 plays an important role in transducing Wnt signals.
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Affiliation(s)
- Jun Liu
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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Heeg-Truesdell E, LaBonne C. A slug, a fox, a pair of sox: transcriptional responses to neural crest inducing signals. ACTA ACUST UNITED AC 2005; 72:124-39. [PMID: 15269887 DOI: 10.1002/bdrc.20011] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The neural crest, a cell type found only in vertebrate embryos, gives rise to the structures of the skull and face and most of the peripheral nervous system, as well as other cell types characteristic of vertebrates. These cells are of great clinical significance and a wide variety of congenital defects are due to aberrant neural crest development. Increasing numbers of studies are contributing to our understanding of how this group of cells form and differentiate during normal development. Wnt, FGF, BMP, and Notch-mediated signals all have essential roles in this process, and several of these signals appear to play multiple temporally distinct roles. Changes in the response of neural crest cells to the same signal over time may be mediated, in part, by an ever-changing cocktail of transcription factors expressed within these cells. Neural crest development is thus a complex multistep process, and elucidating the molecular mechanisms that mediate distinct aspects of this process will require that we determine the role of each of these factors alone and in combination. Here, we review some recent advances in our understanding of the signals and downstream transcription factors involved in neural crest cell formation.
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Affiliation(s)
- Elizabeth Heeg-Truesdell
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois 60208-3500, USA
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50
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Mi K, Johnson GVW. Role of the intracellular domains of LRP5 and LRP6 in activating the Wnt canonical pathway. J Cell Biochem 2005; 95:328-38. [PMID: 15778991 DOI: 10.1002/jcb.20400] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
LDL-receptor related proteins 5 and 6 (LRP5/6) are co-receptors of Frizzled receptors that mediate Wnt-induced activation of the transcription factor family TCF/LEF-1. Even though LRP5 and LRP6 are highly homologous, LRP6, but not LRP5, is expressed primarily in the nervous system and deletion of the LRP6 gene results in significant brain abnormalities, while deletion of LRP5 results in primarily decreased bone density. Additionally, the exact function of LRP5 and LRP6 have not been clearly defined, although it is clear that they both play key roles in the Wnt canonical pathway. In this study the role of the intracellular domains of LRP5/6 in mediating Wnt signaling was examined. In the absence of exogenous Wnt 3a, full-length (FL) LRP6, but not LRP5, increased TCF/LEF-1 transcriptional activity, however both significantly potentiated Wnt 3a-induced TCF/LEF-1 activation. In contrast to the findings with the FL constructs, the intracellular domains (membrane-anchored and cytosolic) of both LRP5 and LRP6 significantly increased TCF/LEF-1 activation in the absence of Wnt 3a, and potentiated the Wnt 3a-induced decrease in beta-catenin phosphorylation, increase in free beta-catenin levels and the increase in TCF/LEF-1 activity. These findings demonstrate that: (1) LRP5 and LRP6 differentially modulate TCF/LEF-1 activation in the absence of Wnt 3a and (2) the intracellular C-terminal domains of LRP5/6 potentiate Wnt 3a-induced TCF/LEF-1 activation whether or not they are membrane-anchored. These findings provide significant new insights into the roles of LRP5/6 in modulating canonical Wnt signaling.
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Affiliation(s)
- Kaihong Mi
- Department of Psychiatry, University of Alabama at Birmingham, Alabama 35294-0017, USA
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