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Liang Y, Luo C, Sun L, Feng T, Yin W, Zhang Y, Mulholland MW, Zhang W, Yin Y. Reduction of specific enterocytes from loss of intestinal LGR4 improves lipid metabolism in mice. Nat Commun 2024; 15:4393. [PMID: 38782937 PMCID: PMC11116434 DOI: 10.1038/s41467-024-48622-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 05/03/2024] [Indexed: 05/25/2024] Open
Abstract
Whether intestinal Leucine-rich repeat containing G-protein-coupled receptor 4 (LGR4) impacts nutrition absorption and energy homeostasis remains unknown. Here, we report that deficiency of Lgr4 (Lgr4iKO) in intestinal epithelium decreased the proportion of enterocytes selective for long-chain fatty acid absorption, leading to reduction in lipid absorption and subsequent improvement in lipid and glucose metabolism. Single-cell RNA sequencing demonstrates the heterogeneity of absorptive enterocytes, with a decrease in enterocytes selective for long-chain fatty acid-absorption and an increase in enterocytes selective for carbohydrate absorption in Lgr4iKO mice. Activation of Notch signaling and concurrent inhibition of Wnt signaling are observed in the transgenes. Associated with these alterations is the substantial reduction in lipid absorption. Decrement in lipid absorption renders Lgr4iKO mice resistant to high fat diet-induced obesity relevant to wild type littermates. Our study thus suggests that targeting intestinal LGR4 is a potential strategy for the intervention of obesity and liver steatosis.
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Affiliation(s)
- Yuan Liang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and State Key Laboratory of Vascular Homeostasis and Remodeling, Peking University, 100191, Beijing, China
| | - Chao Luo
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and State Key Laboratory of Vascular Homeostasis and Remodeling, Peking University, 100191, Beijing, China
| | - Lijun Sun
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and State Key Laboratory of Vascular Homeostasis and Remodeling, Peking University, 100191, Beijing, China
| | - Tiange Feng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and State Key Laboratory of Vascular Homeostasis and Remodeling, Peking University, 100191, Beijing, China
| | - Wenzhen Yin
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and State Key Laboratory of Vascular Homeostasis and Remodeling, Peking University, 100191, Beijing, China
| | - Yunhua Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and State Key Laboratory of Vascular Homeostasis and Remodeling, Peking University, 100191, Beijing, China
| | - Michael W Mulholland
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI, 48109-0346, USA
| | - Weizhen Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, and State Key Laboratory of Vascular Homeostasis and Remodeling, Peking University, 100191, Beijing, China.
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI, 48109-0346, USA.
| | - Yue Yin
- Department of Pharmacology, School of Basic Medical Sciences, and State Key Laboratory of Vascular Homeostasis and Remodeling, Peking University, 100191, Beijing, China.
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Toh Y, Wu L, Park S, Wang A, Tu J, Yu W, Zuo M, Carmon KS, Liu QJ. LGR4 and LGR5 form distinct homodimers that only LGR4 complexes with RNF43/ZNRF3 to provide high affinity binding of R-spondin ligands. Sci Rep 2023; 13:10796. [PMID: 37402772 DOI: 10.1038/s41598-023-37856-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 06/28/2023] [Indexed: 07/06/2023] Open
Abstract
LGR4 and LGR5 are two homologous receptors that potentiate Wnt/β-catenin signaling in response to R-spondin (RSPO) ligands. The RSPO and LGR4 complex binds to and inhibits activities of two related E3 ubiquitin ligases, RNF43 and ZNRF3, and thus protects Wnt receptors from the E3 ligase-mediated degradation. The RSPO and LGR5 complex, however, does not interact with the E3 ligases, and the structural basis of this difference remained unknown. Here we examined the affinities of monovalent and bivalent RSPO ligands in binding to LGR4, RNF43/ZNRF3, and LGR5 in whole cells and found unique features among the receptors and E3 ligases. Monovalent RSPO2 furin domain had much lower affinity in binding to LGR4 or RNF43/ZNRF3 than the bivalent form. In contrast, monovalent and bivalent forms had nearly identical affinity in binding to LGR5. Co-expression of ZNRF3 with LGR4 led to much higher binding affinity of the monovalent form whereas co-expression of ZNRF3 with LGR5 had no effect on the affinity. These results suggest that LGR4 and RNF43/ZNRF3 form a 2:2 dimer that accommodates bivalent binding of RSPO whereas LGR5 forms a homodimer that does not. Structural models are proposed to illustrate how RSPOs bind to LGR4, RNF43/ZNRF3, and LGR5 in whole cells.
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Affiliation(s)
- Yukimatsu Toh
- Center for Translational Cancer Research, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, 1825 Pressler St., Suite 330E, Houston, TX, 77030, USA
| | - Ling Wu
- Center for Translational Cancer Research, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, 1825 Pressler St., Suite 330E, Houston, TX, 77030, USA
| | - Soohyun Park
- Center for Translational Cancer Research, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, 1825 Pressler St., Suite 330E, Houston, TX, 77030, USA
| | - Allison Wang
- Center for Translational Cancer Research, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, 1825 Pressler St., Suite 330E, Houston, TX, 77030, USA
| | - Jianghua Tu
- Center for Translational Cancer Research, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, 1825 Pressler St., Suite 330E, Houston, TX, 77030, USA
| | - Wangsheng Yu
- Center for Translational Cancer Research, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, 1825 Pressler St., Suite 330E, Houston, TX, 77030, USA
| | - Mingxin Zuo
- Center for Translational Cancer Research, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, 1825 Pressler St., Suite 330E, Houston, TX, 77030, USA
| | - Kendra S Carmon
- Center for Translational Cancer Research, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, 1825 Pressler St., Suite 330E, Houston, TX, 77030, USA
| | - Qingyun J Liu
- Center for Translational Cancer Research, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, 1825 Pressler St., Suite 330E, Houston, TX, 77030, USA.
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Crystal structure of LGR ligand α2/β5 from Caenorhabditis elegans with implications for the evolution of glycoprotein hormones. Proc Natl Acad Sci U S A 2023; 120:e2218630120. [PMID: 36574673 PMCID: PMC9910494 DOI: 10.1073/pnas.2218630120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
A family of leucine-rich-repeat-containing G-protein-coupled receptors (LGRs) mediate diverse physiological responses when complexed with their cognate ligands. LGRs are present in all metazoan animals. In humans, the LGR ligands include glycoprotein hormones (GPHs) chorionic gonadotropin (hCG), luteinizing hormone, follicle-stimulating hormone (hFSH), and thyroid-stimulating hormone (hTSH). These hormones are αβ heterodimers of cystine-knot protein chains. LGRs and their ligand chains have coevolved. Ancestral hormone homologs, present in both bilaterian animals and chordates, are identified as α2β5. We have used single-wavelength anomalous diffraction and molecular replacement to determine structures of the α2β5 hormone from Caenorhabditis elegans (Ceα2β5). Ceα2β5 is unglycosylated, as are many other α2β5 hormones. Both Hsα2β5, the human homolog of Ceα2β5, and hTSH activate the same receptor (hTSHR). Despite having little sequence similarity to vertebrate GPHs, apart from the cysteine patterns from core disulfide bridges, Ceα2β5 is generally similar in structure to these counterparts; however, its α2 and β5 subunits are more symmetric as compared with α and β of hCG and hFSH. This quasisymmetry suggests a hypothetical homodimeric antecedent of the α2β5 and αβ heterodimers. Known structures together with AlphaFold models from the sequences for other LGR ligands provide representatives for the molecular evolution of LGR ligands from early metazoans through the present-day GPHs. The experimental Ceα2β5 structure validates its AlphaFold model, and thus also that for Hsα2β5; and interfacial characteristics in a model for the Hsα2β5:hTSHR complex are similar to those found in an experimental hTSH:hTSHR structure.
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Chen Y, Mao C, Gu R, Zhao R, Li W, Ma Z, Jia Y, Yu F, Luo J, Fu Y, Sun J, Kong W. Nidogen-2 is a Novel Endogenous Ligand of LGR4 to Inhibit Vascular Calcification. Circ Res 2022; 131:1037-1054. [PMID: 36354004 DOI: 10.1161/circresaha.122.321614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Vascular calcification is closely related to the all-cause mortality of cardiovascular events. Basement membrane protein nidogen-2 is a key component of the vascular extracellular matrix microenvironment and we recently found it is pivotal for the maintenance of contractile phenotype in vascular smooth muscle cells (VSMCs). However, whether nidogen-2 is involved in VSMCs osteochondrogenic transition and vascular calcification remains unclear. METHODS VSMCs was treated with high-phosphate to study VSMC calcification in vitro. Three different mice models (5/6 nephrectomy-induced chronic renal failure, cholecalciferol-overload, and periadventitially administered with CaCl2) were used to study vascular calcification in vivo. Membrane protein interactome, coimmunoprecipitation, flow cytometric binding assay, surface plasmon resonance, G protein signaling, VSMCs calcium assays were performed to clarify the phenotype and elucidate the molecular mechanisms. RESULTS Nidogen-2 protein levels were significantly reduced in calcified VSMCs and aortas from mice in different vascular calcification model. Nidogen-2 deficiency exacerbated high-phosphate-induced VSMC calcification, whereas the addition of purified nidogen-2 protein markedly alleviated VSMC calcification in vitro. Nidogen-2-/- mice exhibited aggravated aorta calcification compared to wild-type (WT) mice in response to 5/6 nephrectomy, cholecalciferol-overload, and CaCl2 administration. Further unbiased coimmunoprecipitation and interactome analysis of purified nidogen-2 and membrane protein in VSMCs revealed that nidogen-2 directly binds to LGR4 (leucine-rich repeat G-protein-coupled receptor 4) with KD value 26.77 nM. LGR4 deficiency in VSMCs in vitro or in vivo abolished the protective effect of nidogen-2 on vascular calcification. Of interest, nidogen-2 biased activated LGR4-Gαq-PKCα (protein kinase Cα)-AMPKα1 (AMP-activated protein kinase α1) signaling to counteract VSMCs osteogenic transition and mineralization. CONCLUSIONS Nidogen-2 is a novel endogenous ligand of LGR4 that biased activated Gαq- PKCα-AMPKα1 signaling and inhibited vascular calcification.
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Affiliation(s)
- Yufei Chen
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China (Y.C., C.M., R.G., Z.M., Y.J., F.Y., Y.F., J.S., W.K.).,Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China (Y.C., R.G., Z.M., Y.J., F.Y., Y.F., W.K.)
| | - Chenfeng Mao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China (Y.C., C.M., R.G., Z.M., Y.J., F.Y., Y.F., J.S., W.K.).,Beijing Institute of Biotechnology, China (C.M.)
| | - Rui Gu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China (Y.C., C.M., R.G., Z.M., Y.J., F.Y., Y.F., J.S., W.K.).,Beijing Institute of Biotechnology, China (C.M.)
| | - Rujia Zhao
- Key Laboratory Experimental Teratology of the Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, China (R.Z., J.S.)
| | - Weihao Li
- Department of Vascular Surgery, Peking University People's Hospital, Peking University, Beijing, China (W.L.)
| | - Zihan Ma
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China (Y.C., C.M., R.G., Z.M., Y.J., F.Y., Y.F., J.S., W.K.).,Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China (Y.C., R.G., Z.M., Y.J., F.Y., Y.F., W.K.)
| | - Yiting Jia
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China (Y.C., C.M., R.G., Z.M., Y.J., F.Y., Y.F., J.S., W.K.).,Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China (Y.C., R.G., Z.M., Y.J., F.Y., Y.F., W.K.)
| | - Fang Yu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China (Y.C., C.M., R.G., Z.M., Y.J., F.Y., Y.F., J.S., W.K.).,Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China (Y.C., R.G., Z.M., Y.J., F.Y., Y.F., W.K.)
| | - Jian Luo
- Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China (J.L.)
| | - Yi Fu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China (Y.C., C.M., R.G., Z.M., Y.J., F.Y., Y.F., J.S., W.K.).,Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China (Y.C., R.G., Z.M., Y.J., F.Y., Y.F., W.K.)
| | - Jinpeng Sun
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China (Y.C., C.M., R.G., Z.M., Y.J., F.Y., Y.F., J.S., W.K.).,Key Laboratory Experimental Teratology of the Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, China (R.Z., J.S.)
| | - Wei Kong
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China (Y.C., C.M., R.G., Z.M., Y.J., F.Y., Y.F., J.S., W.K.).,Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China (Y.C., R.G., Z.M., Y.J., F.Y., Y.F., W.K.)
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5
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Yang L, Wang J, Gong X, Fan Q, Yang X, Cui Y, Gao X, Li L, Sun X, Li Y, Wang Y. Emerging Roles for LGR4 in Organ Development, Energy Metabolism and Carcinogenesis. Front Genet 2022; 12:728827. [PMID: 35140734 PMCID: PMC8819683 DOI: 10.3389/fgene.2021.728827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 12/30/2021] [Indexed: 11/26/2022] Open
Abstract
The leucine-rich repeats containing G protein-coupled receptor 4 (LGR4) belonging to G protein-coupled receptors (GPCRs) family, had various regulatory roles at multiple cellular types and numerous targeting sites, and aberrant LGR4 signaling played crucial roles in diseases and carcinogenesis. On the basis of these facts, LGR4 may become an appealing therapeutic target for the treatment of diseases and tumors. However, a comprehensive investigation of its functions and applications was still lacking. Hence, this paper provided an overview of the molecular characteristics and signaling mechanisms of LGR4, its involvement in multiple organ development and participation in the modulation of immunology related diseases, metabolic diseases, and oxidative stress damage along with cancer progression. Given that GPCRs accounted for almost a third of current clinical drug targets, the in-depth understanding of the sophisticated connections of LGR4 and its ligands would not only enrich their regulatory networks, but also shed new light on designing novel molecular targeted drugs and small molecule blockers for revolutionizing the treatment of various diseases and tumors.
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Affiliation(s)
- Linlin Yang
- Department of Gynecological Oncology, The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Municipal Key Clinical Specialty, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China
| | - Jing Wang
- Department of Gynecological Oncology, The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Municipal Key Clinical Specialty, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China
| | - Xiaodi Gong
- Department of Gynecological Oncology, The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Municipal Key Clinical Specialty, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China
| | - Qiong Fan
- Department of Gynecological Oncology, The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Municipal Key Clinical Specialty, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China
| | - Xiaoming Yang
- Department of Gynecological Oncology, The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Municipal Key Clinical Specialty, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China
| | - Yunxia Cui
- Department of Gynecological Oncology, The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Municipal Key Clinical Specialty, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China
| | - Xiaoyan Gao
- Department of Gynecological Oncology, The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Municipal Key Clinical Specialty, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China
| | - Lijuan Li
- Department of Gynecological Oncology, The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Municipal Key Clinical Specialty, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China
| | - Xiao Sun
- Department of Gynecological Oncology, The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Municipal Key Clinical Specialty, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China
| | - Yuhong Li
- Department of Gynecological Oncology, The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Municipal Key Clinical Specialty, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China
- *Correspondence: Yuhong Li, ; Yudong Wang,
| | - Yudong Wang
- Department of Gynecological Oncology, The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Municipal Key Clinical Specialty, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China
- *Correspondence: Yuhong Li, ; Yudong Wang,
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Filipowska J, Kondegowda NG, Leon-Rivera N, Dhawan S, Vasavada RC. LGR4, a G Protein-Coupled Receptor With a Systemic Role: From Development to Metabolic Regulation. Front Endocrinol (Lausanne) 2022; 13:867001. [PMID: 35707461 PMCID: PMC9190282 DOI: 10.3389/fendo.2022.867001] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/21/2022] [Indexed: 12/22/2022] Open
Abstract
Leucine-rich repeat-containing G protein-coupled receptor 4 (LGR4/GPR48), a member of the GPCR (G protein-coupled receptors) superfamily, subfamily B, is a common intestinal crypt stem cell marker. It binds R-spondins/Norrin as classical ligands and plays a crucial role in Wnt signaling potentiation. Interaction between LGR4 and R-spondins initiates many Wnt-driven developmental processes, e.g., kidney, eye, or reproductive tract formation, as well as intestinal crypt (Paneth) stem cell pool maintenance. Besides the well-described role of LGR4 in development, several novel functions of this receptor have recently been discovered. In this context, LGR4 was indicated to participate in TGFβ and NFκB signaling regulation in hematopoietic precursors and intestinal cells, respectively, and found to be a new, alternative receptor for RANKL (Receptor Activator of NF kappa B Ligand) in bone cells. LGR4 inhibits the process of osteoclast differentiation, by antagonizing the interaction between RANK (Receptor Activator of NF kappa B) and its ligand-RANKL. It is also known to trigger anti-inflammatory responses in different tissues (liver, intestine, cardiac cells, and skin), serve as a sensor of the circadian clock in the liver, regulate adipogenesis and energy expenditure in adipose tissue and skeletal muscles, respectively. The extracellular domain of LGR4 (LGR4-ECD) has emerged as a potential new therapeutic for osteoporosis and cancer. LGR4 integrates different signaling pathways and regulates various cellular processes vital for maintaining whole-body homeostasis. Yet, the role of LGR4 in many cell types (e.g. pancreatic beta cells) and diseases (e.g., diabetes) remains to be elucidated. Considering the broad spectrum of LGR4 actions, this review aims to discuss both canonical and novel roles of LGR4, with emphasis on emerging research directions focused on this receptor.
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Rajendran R, Sudha D, Chidambaram S, Nagarajan H, Vetrivel U, Arunachalam JP. Retinoschisis and Norrie disease: a missing link. BMC Res Notes 2021; 14:204. [PMID: 34039417 PMCID: PMC8157631 DOI: 10.1186/s13104-021-05617-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 05/15/2021] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE Retinoschisis and Norrie disease are X-linked recessive retinal disorders caused by mutations in RS1 and NDP genes respectively. Both are likely to be monogenic and no locus heterogeneity has been reported. However, there are reports showing overlapping features of Norrie disease and retinoschisis in a NDP knock-out mouse model and also the involvement of both the genes in retinoschisis patients. Yet, the exact molecular relationships between the two disorders have still not been understood. The study investigated the association between retinoschisin (RS1) and norrin (NDP) using in vitro and in silico approaches. Specific protein-protein interaction between RS1 and NDP was analyzed in human retina by co-immunoprecipitation assay and MALDI-TOF mass spectrometry. STRING database was used to explore the functional relationship. RESULT Co-immunoprecipitation demonstrated lack of a direct interaction between RS1 and NDP and was further substantiated by mass spectrometry. However, STRING revealed a potential indirect functional association between the two proteins. Progressively, our analyses indicate that FZD4 protein interactome via PLIN2 as well as the MAP kinase signaling pathway to be a likely link bridging the functional relationship between retinoschisis and Norrie disease.
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Affiliation(s)
- Rahini Rajendran
- Central Inter-Disciplinary Research Facility (CIDRF), Sri Balaji Vidyapeeth (Deemed To Be University), Mahatma Gandhi Medical College and Research Institute Campus, Pondicherry, 607402, India
| | - Dhandayuthapani Sudha
- SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Nungambakkam, Chennai, 600006, India
| | - Subbulakshmi Chidambaram
- Department of Biochemistry and Molecular Biology, Pondicherry University, Puducherry, 605014, India
| | - Hemavathy Nagarajan
- Kamalnayan Bajaj Institute for Research in Vision and Ophthalmology, Vision Research Foundation, Sankara Nethralaya, Chennai, 600006, India
| | - Umashankar Vetrivel
- National Institute of Traditional Medicine, Indian Council of Medical Research, Belagavi, 590010, India
| | - Jayamuruga Pandian Arunachalam
- Central Inter-Disciplinary Research Facility (CIDRF), Sri Balaji Vidyapeeth (Deemed To Be University), Mahatma Gandhi Medical College and Research Institute Campus, Pondicherry, 607402, India. .,SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Nungambakkam, Chennai, 600006, India.
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8
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The Role of LGR4 (GPR48) in Normal and Cancer Processes. Int J Mol Sci 2021; 22:ijms22094690. [PMID: 33946652 PMCID: PMC8125670 DOI: 10.3390/ijms22094690] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/23/2021] [Accepted: 04/23/2021] [Indexed: 12/13/2022] Open
Abstract
Leucine-rich repeats containing G protein-coupled receptor 4 (LGR4) is a receptor that belongs to the superfamily of G protein-coupled receptors that can be activated by R-spondins (RSPOs), Norrin, circLGR4, and the ligand of the receptor activator of nuclear factor kappa-B (RANKL) ligands to regulate signaling pathways in normal and pathological processes. LGR4 is widely expressed in different tissues where it has multiple functions such as tissue development and maintenance. LGR4 mainly acts through the Wnt/β-catenin pathway to regulate proliferation, survival, and differentiation. In cancer, LGR4 participates in tumor progression, invasion, and metastasis. Furthermore, recent evidence reveals that LGR4 is essential for the regulation of the cancer stem cell population by controlling self-renewal and regulating stem cell properties. This review summarizes the function of LGR4 and its ligands in normal and malignant processes.
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Ofek S, Wiszniak S, Kagan S, Tondl M, Schwarz Q, Kalcheim C. Notch signaling is a critical initiator of roof plate formation as revealed by the use of RNA profiling of the dorsal neural tube. BMC Biol 2021; 19:84. [PMID: 33892704 PMCID: PMC8063321 DOI: 10.1186/s12915-021-01014-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 03/25/2021] [Indexed: 12/31/2022] Open
Abstract
Background The dorsal domain of the neural tube is an excellent model to investigate the generation of complexity during embryonic development. It is a highly dynamic and multifaceted region being first transiently populated by prospective neural crest (NC) cells that sequentially emigrate to generate most of the peripheral nervous system. Subsequently, it becomes the definitive roof plate (RP) of the central nervous system. The RP, in turn, constitutes a patterning center for dorsal interneuron development. The factors underlying establishment of the definitive RP and its segregation from NC and dorsal interneurons are currently unknown. Results We performed a transcriptome analysis at trunk levels of quail embryos comparing the dorsal neural tube at premigratory NC and RP stages. This unraveled molecular heterogeneity between NC and RP stages, and within the RP itself. By implementing these genes, we asked whether Notch signaling is involved in RP development. First, we observed that Notch is active at the RP-interneuron interface. Furthermore, gain and loss of Notch function in quail and mouse embryos, respectively, revealed no effect on early NC behavior. Constitutive Notch activation caused a local downregulation of RP markers with a concomitant development of dI1 interneurons, as well as an ectopic upregulation of RP markers in the interneuron domain. Reciprocally, in mice lacking Notch activity, both the RP and dI1 interneurons failed to form and this was associated with expansion of the dI2 population. Conclusions Collectively, our results offer a new resource for defining specific cell types, and provide evidence that Notch is required to establish the definitive RP, and to determine the choice between RP and interneuron fates, but not the segregation of RP from NC.
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Affiliation(s)
- Shai Ofek
- Department of Medical Neurobiology, Institute of Medical Research Israel-Canada (IMRIC) and the Edmond and Lily Safra Center for Brain Sciences (ELSC), Hebrew University of Jerusalem-Hadassah Medical School, P.O.Box 12272, 9112102, Jerusalem, Israel
| | - Sophie Wiszniak
- Centre for Cancer Biology, University of South Australia and SA Pathology, North Terrace, Adelaide, SA, 5001, Australia
| | - Sarah Kagan
- Department of Medical Neurobiology, Institute of Medical Research Israel-Canada (IMRIC) and the Edmond and Lily Safra Center for Brain Sciences (ELSC), Hebrew University of Jerusalem-Hadassah Medical School, P.O.Box 12272, 9112102, Jerusalem, Israel
| | - Markus Tondl
- Centre for Cancer Biology, University of South Australia and SA Pathology, North Terrace, Adelaide, SA, 5001, Australia
| | - Quenten Schwarz
- Centre for Cancer Biology, University of South Australia and SA Pathology, North Terrace, Adelaide, SA, 5001, Australia.
| | - Chaya Kalcheim
- Department of Medical Neurobiology, Institute of Medical Research Israel-Canada (IMRIC) and the Edmond and Lily Safra Center for Brain Sciences (ELSC), Hebrew University of Jerusalem-Hadassah Medical School, P.O.Box 12272, 9112102, Jerusalem, Israel.
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10
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El-Sehemy A, Selvadurai H, Ortin-Martinez A, Pokrajac N, Mamatjan Y, Tachibana N, Rowland K, Lee L, Park N, Aldape K, Dirks P, Wallace VA. Norrin mediates tumor-promoting and -suppressive effects in glioblastoma via Notch and Wnt. J Clin Invest 2021; 130:3069-3086. [PMID: 32182224 DOI: 10.1172/jci128994] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 03/05/2020] [Indexed: 12/28/2022] Open
Abstract
Glioblastoma multiforme (GBM) contains a subpopulation of cells, GBM stem cells (GSCs), that maintain the bulk tumor and represent a key therapeutic target. Norrin is a Wnt ligand that binds Frizzled class receptor 4 (FZD4) to activate canonical Wnt signaling. Although Norrin, encoded by NDP, has a well-described role in vascular development, its function in human tumorigenesis is largely unexplored. Here, we show that NDP expression is enriched in neurological cancers, including GBM, and its levels positively correlated with survival in a GBM subtype defined by low expression of ASCL1, a proneural factor. We investigated the function of Norrin and FZD4 in GSCs and found that it mediated opposing tumor-suppressive and -promoting effects on ASCL1lo and ASCL1hi GSCs. Consistent with a potential tumor-suppressive effect of Norrin suggested by the tumor outcome data, we found that Norrin signaling through FZD4 inhibited growth in ASCL1lo GSCs. In contrast, in ASCL1hi GSCs Norrin promoted Notch signaling, independently of WNT, to promote tumor progression. Forced ASCL1 expression reversed the tumor-suppressive effects of Norrin in ASCL1lo GSCs. Our results identify Norrin as a modulator of human brain cancer progression and reveal an unanticipated Notch-mediated function of Norrin in regulating cancer stem cell biology. This study identifies an unanticipated role of Norrin in human brain cancer progression. In addition, we provide preclinical evidence suggesting Norrin and canonical Wnt signaling as potential therapeutic targets for GBM subtype-restricted cancer stem cells.
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Affiliation(s)
- Ahmed El-Sehemy
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.,Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada
| | - Hayden Selvadurai
- Developmental and Stem Cell Biology Program and.,Arthur and Sonia Labatt Brain Tumour Research Centre, Hospital for Sick Children, Toronto, Canada
| | - Arturo Ortin-Martinez
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.,Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada
| | - Neno Pokrajac
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.,Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada
| | - Yasin Mamatjan
- MacFeeters Hamilton Centre for Neuro-Oncology Research, Princess Margaret Cancer Centre, Toronto, Canada
| | - Nobuhiko Tachibana
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.,Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada
| | - Katherine Rowland
- Developmental and Stem Cell Biology Program and.,Arthur and Sonia Labatt Brain Tumour Research Centre, Hospital for Sick Children, Toronto, Canada
| | - Lilian Lee
- Developmental and Stem Cell Biology Program and.,Arthur and Sonia Labatt Brain Tumour Research Centre, Hospital for Sick Children, Toronto, Canada
| | - Nicole Park
- Developmental and Stem Cell Biology Program and.,Arthur and Sonia Labatt Brain Tumour Research Centre, Hospital for Sick Children, Toronto, Canada
| | - Kenneth Aldape
- MacFeeters Hamilton Centre for Neuro-Oncology Research, Princess Margaret Cancer Centre, Toronto, Canada.,Laboratory of Pathology, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Peter Dirks
- Developmental and Stem Cell Biology Program and.,Arthur and Sonia Labatt Brain Tumour Research Centre, Hospital for Sick Children, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Division of Neurosurgery, Hospital for Sick Children, Toronto, Canada
| | - Valerie A Wallace
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.,Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada
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11
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Kassumeh S, Priglinger SG, Ohlmann A. Norrin mediates opposing effects on tumor progression of glioblastoma stem cells. J Clin Invest 2021; 130:2814-2815. [PMID: 32391807 DOI: 10.1172/jci137254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Glioblastoma is the most common human brain cancer entity and is maintained by a glioblastoma stem cell (GSC) subpopulation. In this issue of the JCI, El-Sehemy and colleagues explored the effects that Norrin, a well-characterized activator of Wnt/β-catenin signaling, had on tumor growth. Norrin inhibited cell growth via β-catenin signaling in GSCs that had low expression levels of the transcription factor ASCL1. However, Norrin had the opposite effect in GSCs with high ASCL1 expression levels. The modulation of Norrin expression, with respect to high or low ASCL1 levels in GSCs, significantly reduced tumor growth in vivo, and subsequently increased the survival rate of mice. Notably, Norrin mediates enhanced tumor growth of glioblastomas by activating the Notch pathway. This study clarifies the opposing effects of Norrin on glioblastoma tumor growth and provides potential therapeutic targets for glioblastoma treatment.
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12
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Augusto-Oliveira M, Arrifano GP, Takeda PY, Lopes-Araújo A, Santos-Sacramento L, Anthony DC, Verkhratsky A, Crespo-Lopez ME. Astroglia-specific contributions to the regulation of synapses, cognition and behaviour. Neurosci Biobehav Rev 2020; 118:331-357. [DOI: 10.1016/j.neubiorev.2020.07.039] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/29/2020] [Accepted: 07/29/2020] [Indexed: 12/11/2022]
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13
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Zhang D, Wang Y, Lin H, Sun Y, Wang M, Jia Y, Yu X, Jiang H, Xu W, Sun JP, Xu Z. Function and therapeutic potential of G protein-coupled receptors in epididymis. Br J Pharmacol 2020; 177:5489-5508. [PMID: 32901914 DOI: 10.1111/bph.15252] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 08/08/2020] [Accepted: 09/03/2020] [Indexed: 12/14/2022] Open
Abstract
Infertility rates for both females and males have increased continuously in recent years. Currently, effective treatments for male infertility with defined mechanisms or targets are still lacking. G protein-coupled receptors (GPCRs) are the largest class of drug targets, but their functions and the implications for the therapeutic development for male infertility largely remain elusive. Nevertheless, recent studies have shown that several members of the GPCR superfamily play crucial roles in the maintenance of ion-water homeostasis of the epididymis, development of the efferent ductules, formation of the blood-epididymal barrier and maturation of sperm. Knowledge of the functions, genetic variations and working mechanisms of such GPCRs, along with the drugs and ligands relevant to their specific functions, provide future directions and a great arsenal for new developments in the treatment of male infertility.
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Affiliation(s)
- Daolai Zhang
- Department of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China.,Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan, China
| | - Yanfei Wang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Hui Lin
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan, China
| | - Yujing Sun
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan, China
| | - Mingwei Wang
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan, China
| | - Yingli Jia
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Peking University, Beijing, China
| | - Xiao Yu
- Department of Physiology, School of Medicine, Shandong University, Jinan, China
| | - Hui Jiang
- Department of Urology, Peking University Third Hospital, Beijing, China.,Department of Reproductive Medicine Center, Peking University Third Hospital, Beijing, China
| | - Wenming Xu
- Joint Laboratory of Reproductive Medicine, SCU-CUHK, Key Laboratory of Obstetric, Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University West China Second University Hospital, Chengdu, China
| | - Jin-Peng Sun
- Department of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China.,Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan, China.,Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Peking University, Beijing, China
| | - Zhigang Xu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China.,Shandong Provincial Collaborative Innovation Center of Cell Biology, Shandong Normal University, Jinan, China
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14
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Lai S, Cheng R, Gao D, Chen YG, Deng C. LGR5 constitutively activates NF-κB signaling to regulate the growth of intestinal crypts. FASEB J 2020; 34:15605-15620. [PMID: 33001511 DOI: 10.1096/fj.202001329r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 09/01/2020] [Accepted: 09/22/2020] [Indexed: 01/09/2023]
Abstract
Mammalian LGR5 and LGR4, markers of adult stem cells, are involved in many physiological functions by enhancing WNT signaling. However, whether LGR5 and LGR4 are coupled to other intracellular signaling pathways to regulate stem cell function remains unknown. Here, we show that LGR5 and LGR4 can constitutively activate NF-κB signaling in a ligand-independent manner, which is dependent on their C-termini, but independent of receptor endocytosis. Moreover, the C-termini of LGR5/4 interact with TROY, which is required for activating NF-κB signaling. In small intestinal crypt organoids, overexpression of a C-terminal deletion mutant of LGR5 inhibits the growth and bud formation of organoids, whereas overexpression of the R-spondin-binding mutant of LGR5 that is defective for WNT signaling can still promote organoid growth. Our study reveals that NF-κB signaling, regulated by LGR5 and LGR4, plays an important role in the survival of colon cancer cells and the growth of intestinal crypts. Our findings also suggest that LGR5/4-induced NF-κB signaling and WNT signaling may co-regulate the growth of LGR5+ adult stem cells and intestinal crypts.
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Affiliation(s)
- Shanshan Lai
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ran Cheng
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Dan Gao
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ye-Guang Chen
- The State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Cheng Deng
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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15
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Hsueh AJW, Feng Y. Discovery of polypeptide ligand-receptor pairs based on their co-evolution. FASEB J 2020; 34:8824-8832. [PMID: 32501617 DOI: 10.1096/fj.202000779r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/05/2020] [Accepted: 05/07/2020] [Indexed: 12/18/2022]
Abstract
Sequencing diverse genomes allowed the tracing of orthologous and paralogous genes to understand the co-evolution of polypeptide ligands and receptors. This review documents the discovery of several polypeptide ligands and their cognate receptors mainly expressed in the reproductive tissue using evolutionary genomics. We discussed the sub-functionization of paralogs and co-evolution of ligand-receptor families. Based on the conserved signaling among paralogous receptors and common knock-out phenotypes of ligand-receptor pairs, relationships between relaxin family peptides and leucine-rich repeat-containing, G protein-coupled receptors (LGR) were revealed. We also described the identification of a novel paralogous glycoprotein hormone thyrostimulin and design of a long-acting FSH. Human stresscopin and stresscopin-related peptide, paralogous to CRH, were also identified based on the conserved signaling pathways. Recently, a novel ligand placensin expressed in human placenta was found based on the paralogous relationship with a metabolic hormone asprosin. Placensin likely contributes to stage-dependent increases in insulin resistance during human pregnancy and its elevated secretion was associated with gestational diabetes mellitus. Although many ligands were predicted based on sequence signatures, ligands of shorter sequences have not been identified, together with many "orphan" receptors without known ligands. Future development of tools for predicting ligands and high throughput assays to identify ligand-receptor pairs based on ligand binding and/or signal transduction could advance hormone-based physiology and pathophysiology.
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Affiliation(s)
- Aaron J W Hsueh
- Division of Reproductive and Stem Cell Biology, Departments of Obstetrics and Gynecology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Yi Feng
- Division of Reproductive and Stem Cell Biology, Departments of Obstetrics and Gynecology, School of Medicine, Stanford University, Stanford, CA, USA.,Department of Integrative Medicine and Neurobiology, State Key Lab of Medical Neurobiology, Institute of Integrative Medicine, Institute of Brain Science, School of Basic Medical Sciences, Fudan University, Shanghai, China
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16
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Boesl F, Drexler K, Müller B, Seitz R, Weber GR, Priglinger SG, Fuchshofer R, Tamm ER, Ohlmann A. Endogenous Wnt/β-catenin signaling in Müller cells protects retinal ganglion cells from excitotoxic damage. Mol Vis 2020; 26:135-149. [PMID: 32180679 PMCID: PMC7058433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 03/03/2020] [Indexed: 11/18/2022] Open
Abstract
Purpose To analyze whether activation of endogenous wingless (Wnt)/β-catenin signaling in Müller cells is involved in protection of retinal ganglion cells (RGCs) following excitotoxic damage. Methods Transgenic mice with a tamoxifen-dependent β-catenin deficiency in Müller cells were injected with N-methyl-D-aspartate (NMDA) into the vitreous cavity of one eye to induce excitotoxic damage of the RGCs, while the contralateral eye received PBS only. Retinal damage was quantified by counting the total number of RGC axons in cross sections of optic nerves and measuring the thickness of the retinal layers on meridional sections. Then, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay was performed to identify apoptotic cells in retinas of both genotypes. Western blot analyses to assess the level of retinal β-catenin and real-time RT-PCR to quantify the retinal expression of neuroprotective factors were performed. Results Following NMDA injection of wild-type mice, a statistically significant increase in retinal β-catenin protein levels was observed compared to PBS-injected controls, an effect that was blocked in mice with a Müller cell-specific β-catenin deficiency. Furthermore, in mice with a β-catenin deficiency in Müller cells, NMDA injection led to a statistically significant decrease in RGC axons as well as a substantial increase in TUNEL-positive cells in the RGC layer compared to the NMDA-treated controls. Moreover, in the retinas of the control mice a NMDA-mediated statistically significant induction of leukemia inhibitory factor (Lif) mRNA was detected, an effect that was substantially reduced in mice with a β-catenin deficiency in Müller cells. Conclusions Endogenous Wnt/β-catenin signaling in Müller cells protects RGCs against excitotoxic damage, an effect that is most likely mediated via the induction of neuroprotective factors, such as Lif.
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Affiliation(s)
- Fabian Boesl
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany
| | - Konstantin Drexler
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany
| | - Birgit Müller
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany
| | - Roswitha Seitz
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany
| | - Gregor R. Weber
- Department of Ophthalmology, University Hospital, Ludwig-Maximilians-University Munich, Germany
| | - Siegfried G. Priglinger
- Department of Ophthalmology, University Hospital, Ludwig-Maximilians-University Munich, Germany
| | - Rudolf Fuchshofer
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany
| | - Ernst R. Tamm
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany
| | - Andreas Ohlmann
- Department of Ophthalmology, University Hospital, Ludwig-Maximilians-University Munich, Germany
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17
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Dzobo K, Thomford NE, Senthebane DA. Targeting the Versatile Wnt/β-Catenin Pathway in Cancer Biology and Therapeutics: From Concept to Actionable Strategy. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2019; 23:517-538. [PMID: 31613700 DOI: 10.1089/omi.2019.0147] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This expert review offers a critical synthesis of the latest insights and approaches at targeting the Wnt/β-catenin pathway in various cancers such as colorectal cancer, melanoma, leukemia, and breast and lung cancers. Notably, from organogenesis to cancer, the Wnt/β-catenin signaling displays varied and highly versatile biological functions in animals, with virtually all tissues requiring the Wnt/β-catenin signaling in one way or the other. Aberrant expression of the members of the Wnt/β-catenin has been implicated in many pathological conditions, particularly in human cancers. Mutations in the Wnt/β-catenin pathway genes have been noted in diverse cancers. Biochemical and genetic data support the idea that inhibition of Wnt/β-catenin signaling is beneficial in cancer therapeutics. The interaction of this important pathway with other signaling systems is also noteworthy, but remains as an area for further research and discovery. In addition, formation of different complexes by components of the Wnt/β-catenin pathway and the precise roles of these complexes in the cytoplasmic milieu are yet to be fully elucidated. This article highlights the latest medical technologies in imaging, single-cell omics, use of artificial intelligence (e.g., machine learning techniques), genome sequencing, quantum computing, molecular docking, and computational softwares in modeling interactions between molecules and predicting protein-protein and compound-protein interactions pertinent to the biology and therapeutic value of the Wnt/β-catenin signaling pathway. We discuss these emerging technologies in relationship to what is currently needed to move from concept to actionable strategies in translating the Wnt/β-catenin laboratory discoveries to Wnt-targeted cancer therapies and diagnostics in the clinic.
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Affiliation(s)
- Kevin Dzobo
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Cape Town, South Africa.,Division of Medical Biochemistry and Institute of Infectious Disease and Molecular Medicine, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Nicholas Ekow Thomford
- Pharmacogenetics Research Group, Division of Human Genetics, Department of Pathology and Institute of Infectious Diseases and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Dimakatso A Senthebane
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Cape Town, South Africa.,Division of Medical Biochemistry and Institute of Infectious Disease and Molecular Medicine, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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18
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Li W, Wang Z, Sun Y, Wang Z, Bai J, Xing B, Sun X, Wang L, Li J, He W. A start codon mutation of the TSPAN12 gene in Chinese families causes clinical heterogeneous familial exudative vitreoretinopathy. Mol Genet Genomic Med 2019; 7:e00948. [PMID: 31452356 PMCID: PMC6785457 DOI: 10.1002/mgg3.948] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 07/14/2019] [Accepted: 07/22/2019] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Familial exudative vitreoretinopathy (FEVR) is a severe clinically and genetically heterogeneous retinal disorder characterized with failure of vascular development of the peripheral retina. The symptoms of FEVR vary widely among patients in the same family, and even between the two eyes of a given patient. The purpose of this study was to investigate the molecular mechanisms by which the start codon mutation of the TSPAN12 causes difference in clinical manifestations between individuals in the same family. METHODS Next-generation sequencing (NGS)-based target capture sequencing was performed in proband with a diagnosis of FEVR and their normal visual acuity family members. Cosegregation analysis of the candidate causative variant was performed in additional family members by using Sanger sequencing. Complete fundus examination, fundus fluorescein angiography (FFA), and family history collection were performed in all family members. Potential candidate causative variants were verified with reference to guidelines and standards from the American College of Medical Genetics and Genomics. RESULTS We identified a novel heterozygous missense mutation (c.1A>G, p.M1V) localized in the start codon of the TSPAN12 and was detected as a potentially disease-causing variant for the proband. Retrospective analysis of clinical data, fundus examination, and FFA showed that the mutant carrier presented peripheral retinal vascular anomalies in early stages, and visual acuity did not show significant effects. However, the proband who carried this mutation and his cousin showed typical high-stage FEVR fundus changes coupled with a sharp decline in vision. CONCLUSIONS We report a novel start codon mutation (c.1A>G, p.M1V) in the TSPAN12 that causes clinically heterogeneous manifestations. Our results expand the mutation spectrums of TSPAN12, and will be valuable for disease diagnosis, prognosis, genetic counseling, and enriching our understanding of the role of the tetraspanin-12 protein in the pathogenesis of FEVR.
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Affiliation(s)
- Wei Li
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China.,He's university, Shenyang, China
| | - Ziwei Wang
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China
| | - Yan Sun
- He's university, Shenyang, China.,Shenyang He Eye Specialist Hospital, Shenyang, China
| | - Zhuoshi Wang
- He's university, Shenyang, China.,Shenyang He Eye Specialist Hospital, Shenyang, China
| | - Jinyue Bai
- School of Basic Medicine, Qingdao University, Qingdao, China
| | - Bo Xing
- School of Basic Medicine, Qingdao University, Qingdao, China
| | - Xiao Sun
- School of Basic Medicine, Qingdao University, Qingdao, China
| | - Lusheng Wang
- He's university, Shenyang, China.,Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong
| | - Jiankang Li
- He's university, Shenyang, China.,Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong
| | - Wei He
- He's university, Shenyang, China.,Shenyang He Eye Specialist Hospital, Shenyang, China
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19
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Wu J, Li X, Li D, Ren X, Li Y, Herter EK, Qian M, Toma MA, Wintler AM, Sérézal IG, Rollman O, Ståhle M, Wikstrom JD, Ye X, Landén NX. MicroRNA-34 Family Enhances Wound Inflammation by Targeting LGR4. J Invest Dermatol 2019; 140:465-476.e11. [PMID: 31376385 DOI: 10.1016/j.jid.2019.07.694] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/18/2019] [Accepted: 07/16/2019] [Indexed: 12/20/2022]
Abstract
Venous ulcers are the most common type of human chronic nonhealing wounds and are stalled in a constant and excessive inflammatory state. The molecular mechanisms underlying the chronic wound inflammation remain elusive. Moreover, little is known about the role of regulatory RNAs, such as microRNAs, in the pathogenesis of venous ulcers. We found that both microRNA (miR)-34a and miR-34c were upregulated in the wound-edge epidermal keratinocytes of venous ulcers compared with normal wounds or the skin. In keratinocytes, miR-34a and miR-34c promoted inflammatory chemokine and cytokine production. In wounds of wild-type mice, miR-34a-mimic treatment enhanced inflammation and delayed healing. To further explore how miR-34 functions, LGR4 was identified as a direct target mediating the proinflammatory function of miR-34a and miR-34c. Interestingly, impaired wound closure with enhanced inflammation was also observed in Lgr4 knockout mice. Mechanistically, the miR-34-LGR4 axis regulated GSK-3β-induced p65 serine 468 phosphorylation, changing the activity of the NF-κB signaling pathway. Collectively, the miR-34-LGR4 axis was shown to regulate keratinocyte inflammatory response, the deregulation of which may play a pathological role in venous ulcers.
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Affiliation(s)
- Jianmin Wu
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China; Dermatology and Venereology Division, Department of Medicine (Solna), Karolinska Institute, Stockholm, Sweden.
| | - Xi Li
- Dermatology and Venereology Division, Department of Medicine (Solna), Karolinska Institute, Stockholm, Sweden
| | - Dongqing Li
- Dermatology and Venereology Division, Department of Medicine (Solna), Karolinska Institute, Stockholm, Sweden
| | - Xiaolin Ren
- Institute of Biomedical Science and School of Life Science, East China Normal University, Shanghai, China
| | - Yijuan Li
- Institute of Biomedical Science and School of Life Science, East China Normal University, Shanghai, China
| | - Eva K Herter
- Dermatology and Venereology Division, Department of Medicine (Solna), Karolinska Institute, Stockholm, Sweden
| | - Mengyao Qian
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China
| | - Maria-Alexandra Toma
- Dermatology and Venereology Division, Department of Medicine (Solna), Karolinska Institute, Stockholm, Sweden
| | - Anna-Maria Wintler
- Dermatology and Venereology Division, Department of Medicine (Solna), Karolinska Institute, Stockholm, Sweden
| | - Irène Gallais Sérézal
- Dermatology and Venereology Division, Department of Medicine (Solna), Karolinska Institute, Stockholm, Sweden; Dermato-Venereology Clinic, Karolinska University Hospital, Stockholm, Sweden
| | - Ola Rollman
- Department of Dermatology, Academic University Hospital, Uppsala, Sweden
| | - Mona Ståhle
- Dermatology and Venereology Division, Department of Medicine (Solna), Karolinska Institute, Stockholm, Sweden; Dermato-Venereology Clinic, Karolinska University Hospital, Stockholm, Sweden
| | - Jakob D Wikstrom
- Dermatology and Venereology Division, Department of Medicine (Solna), Karolinska Institute, Stockholm, Sweden; Dermato-Venereology Clinic, Karolinska University Hospital, Stockholm, Sweden.
| | - Xiyun Ye
- Institute of Biomedical Science and School of Life Science, East China Normal University, Shanghai, China.
| | - Ning Xu Landén
- Dermatology and Venereology Division, Department of Medicine (Solna), Karolinska Institute, Stockholm, Sweden; Ming Wai Lau Centre for Reparative Medicine, Stockholm node, Karolinska Institute, Stockholm, Sweden.
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20
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Miller SJ, Philips T, Kim N, Dastgheyb R, Chen Z, Hsieh YC, Daigle JG, Datta M, Chew J, Vidensky S, Pham JT, Hughes EG, Robinson MB, Sattler R, Tomer R, Suk JS, Bergles DE, Haughey N, Pletnikov M, Hanes J, Rothstein JD. Molecularly defined cortical astroglia subpopulation modulates neurons via secretion of Norrin. Nat Neurosci 2019; 22:741-752. [PMID: 30936556 PMCID: PMC6551209 DOI: 10.1038/s41593-019-0366-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 02/15/2019] [Indexed: 11/09/2022]
Abstract
Despite expanding knowledge regarding the role of astroglia in regulating neuronal function, little is known about regional or functional subgroups of brain astroglia and how they may interact with neurons. We use an astroglia-specific promoter fragment in transgenic mice to identify an anatomically defined subset of adult gray matter astroglia. Using transcriptomic and histological analyses, we generate a combinatorial profile for the in vivo identification and characterization of this astroglia subpopulation. These astroglia are enriched in mouse cortical layer V; express distinct molecular markers, including Norrin and leucine-rich repeat-containing G-protein-coupled receptor 6 (LGR6), with corresponding layer-specific neuronal ligands; are found in the human cortex; and modulate neuronal activity. Astrocytic Norrin appears to regulate dendrites and spines; its loss, as occurring in Norrie disease, contributes to cortical dendritic spine loss. These studies provide evidence that human and rodent astroglia subtypes are regionally and functionally distinct, can regulate local neuronal dendrite and synaptic spine development, and contribute to disease.
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Affiliation(s)
- Sean J Miller
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Cellular & Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Thomas Philips
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Namho Kim
- The Center for Nanomedicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Raha Dastgheyb
- Department of Neurology, Richard T. Johnson Division of Neuroimmunology and Neurological Infections, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Zhuoxun Chen
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yi-Chun Hsieh
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - J Gavin Daigle
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Malika Datta
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Jeannie Chew
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Svetlana Vidensky
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jacqueline T Pham
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Cellular & Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ethan G Hughes
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Michael B Robinson
- Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA, USA
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Rita Sattler
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Raju Tomer
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Jung Soo Suk
- The Center for Nanomedicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Departments of Biomedical Engineering, Environmental and Health Sciences, Oncology, Neurosurgery, and Pharmacology and Molecular Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Dwight E Bergles
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Norman Haughey
- Department of Neurology, Richard T. Johnson Division of Neuroimmunology and Neurological Infections, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mikhail Pletnikov
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Justin Hanes
- The Center for Nanomedicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
- Departments of Biomedical Engineering, Environmental and Health Sciences, Oncology, Neurosurgery, and Pharmacology and Molecular Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Jeffrey D Rothstein
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Cellular & Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Interplay of the Norrin and Wnt7a/Wnt7b signaling systems in blood-brain barrier and blood-retina barrier development and maintenance. Proc Natl Acad Sci U S A 2018; 115:E11827-E11836. [PMID: 30478038 DOI: 10.1073/pnas.1813217115] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
β-Catenin signaling controls the development and maintenance of the blood-brain barrier (BBB) and the blood-retina barrier (BRB), but the division of labor and degree of redundancy between the two principal ligand-receptor systems-the Norrin and Wnt7a/Wnt7b systems-are incompletely defined. Here, we present a loss-of-function genetic analysis of postnatal BBB and BRB maintenance in mice that shows striking threshold and partial redundancy effects. In particular, the combined loss of Wnt7a and Norrin or Wnt7a and Frizzled4 (Fz4) leads to anatomically localized BBB defects that are far more severe than observed with loss of Wnt7a, Norrin, or Fz4 alone. In the cerebellum, selective loss of Wnt7a in glia combined with ubiquitous loss of Norrin recapitulates the phenotype observed with ubiquitous loss of both Wnt7a and Norrin, implying that glia are the source of Wnt7a in the cerebellum. Tspan12, a coactivator of Norrin signaling in the retina, is also active in BBB maintenance but is less potent than Norrin, consistent with a model in which Tspan12 enhances the amplitude of the Norrin signal in vascular endothelial cells. Finally, in the context of a partially impaired Norrin system, the retina reveals a small contribution to BRB development from the Wnt7a/Wnt7b system. Taken together, these experiments define the extent of CNS region-specific cooperation for several components of the Norrin and Wnt7a/Wnt7b systems, and they reveal substantial regional heterogeneity in the extent to which partially redundant ligands, receptors, and coactivators maintain the BBB and BRB.
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22
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Vickrey AI, Bruders R, Kronenberg Z, Mackey E, Bohlender RJ, Maclary ET, Maynez R, Osborne EJ, Johnson KP, Huff CD, Yandell M, Shapiro MD. Introgression of regulatory alleles and a missense coding mutation drive plumage pattern diversity in the rock pigeon. eLife 2018; 7:e34803. [PMID: 30014848 PMCID: PMC6050045 DOI: 10.7554/elife.34803] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 06/05/2018] [Indexed: 12/17/2022] Open
Abstract
Birds and other vertebrates display stunning variation in pigmentation patterning, yet the genes controlling this diversity remain largely unknown. Rock pigeons (Columba livia) are fundamentally one of four color pattern phenotypes, in decreasing order of melanism: T-check, checker, bar (ancestral), or barless. Using whole-genome scans, we identified NDP as a candidate gene for this variation. Allele-specific expression differences in NDP indicate cis-regulatory divergence between ancestral and melanistic alleles. Sequence comparisons suggest that derived alleles originated in the speckled pigeon (Columba guinea), providing a striking example of introgression. In contrast, barless rock pigeons have an increased incidence of vision defects and, like human families with hereditary blindness, carry start-codon mutations in NDP. In summary, we find that both coding and regulatory variation in the same gene drives wing pattern diversity, and post-domestication introgression supplied potentially advantageous melanistic alleles to feral populations of this ubiquitous urban bird.
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Affiliation(s)
- Anna I Vickrey
- School of Biological SciencesUniversity of UtahSalt Lake CityUnited States
| | - Rebecca Bruders
- School of Biological SciencesUniversity of UtahSalt Lake CityUnited States
| | - Zev Kronenberg
- Department of Human GeneticsUniversity of UtahSalt Lake CityUnited States
| | - Emma Mackey
- School of Biological SciencesUniversity of UtahSalt Lake CityUnited States
| | - Ryan J Bohlender
- Department of Epidemiology, MD Anderson Cancer CenterUniversity of TexasHoustonUnited States
| | - Emily T Maclary
- School of Biological SciencesUniversity of UtahSalt Lake CityUnited States
| | - Raquel Maynez
- School of Biological SciencesUniversity of UtahSalt Lake CityUnited States
| | - Edward J Osborne
- Department of Human GeneticsUniversity of UtahSalt Lake CityUnited States
| | - Kevin P Johnson
- Illinois Natural History Survey, Prairie Research InstituteUniversity of Illinois Urbana-ChampaignChampaignUnited States
| | - Chad D Huff
- Department of Epidemiology, MD Anderson Cancer CenterUniversity of TexasHoustonUnited States
| | - Mark Yandell
- Department of Human GeneticsUniversity of UtahSalt Lake CityUnited States
| | - Michael D Shapiro
- School of Biological SciencesUniversity of UtahSalt Lake CityUnited States
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Becker J, Wilting J. WNT signaling, the development of the sympathoadrenal-paraganglionic system and neuroblastoma. Cell Mol Life Sci 2018; 75:1057-1070. [PMID: 29058015 PMCID: PMC5814469 DOI: 10.1007/s00018-017-2685-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 09/22/2017] [Accepted: 10/11/2017] [Indexed: 12/04/2022]
Abstract
Neuroblastoma (NB) is a tumor of the sympathoadrenal system arising in children under 15 years of age. In Germany, NB accounts for 7% of childhood cancer cases, but 11% of cancer deaths. It originates from highly migratory progenitor cells that leave the dorsal neural tube and contribute neurons and glial cells to sympathetic ganglia, and chromaffin and supportive cells to the adrenal medulla and paraganglia. Clinically, histologically and molecularly, NBs present as extremely heterogeneous, ranging from very good to very poor prognosis. The etiology of NB still remains unclear and needs to be elucidated, however, aberrant auto- and paracrine embryonic cell communications seem to be likely candidates to initiate or facilitate the emergence, progression and regression of NB. The wingless-type MMTV integration site (WNT) family of proteins represents an evolutionary highly conserved signaling system that orchestrates embryogenesis. At least 19 ligands in the human, numerous receptors and co-receptors are known, which control not only proliferation, but also cell polarity, migration and differentiation. Here we seek to interconnect aspects of WNT signaling with sympathoadrenal and paraganglionic development to define new WNT signaling cues in the etiology and progression of NB.
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Affiliation(s)
- Jürgen Becker
- Institute of Anatomy and Cell Biology, University Medical School Göttingen, 37075, Göttingen, Germany.
| | - Jörg Wilting
- Institute of Anatomy and Cell Biology, University Medical School Göttingen, 37075, Göttingen, Germany
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Jia B, Huang L, Chen Y, Liu S, Chen C, Xiong K, Song L, Zhou Y, Yang X, Zhong M. A novel contiguous deletion involving NDP, MAOB and EFHC2 gene in a patient with familial Norrie disease: bilateral blindness and leucocoria without other deficits. J Genet 2018; 96:1015-1020. [PMID: 29321361 DOI: 10.1007/s12041-017-0869-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Contiguous microdeletions of the Norrie disease pseudoglioma (NDP) region on chromosome Xp11.3 have been widely confirmed as contributing to the typical clinical features of Norrie disease (ND). However, the precise relation between genotype and phenotype could vary. The contiguous deletion of NDP and its neighbouring genes, MAOA/B and EFHC2, reportedly leads to syndromic clinical features such as microcephaly, intellectual disability, and epilepsy. Herewe report a novel contiguous microdeletion of the NDP region containing the MAOB and EFHC2 genes,which causes eye defects but no cognitive disability.We detected a deletion of 494.6 kb atXp11.3 in both the proband and carrier mother. This deletionwas then used as the molecular marker in prenatal diagnosis for two subsequent pregnancies. The deletion was absent in one of the foetuses, who remain without any abnormalities at 2 years of age. The proband shows the typical ocular clinical features of ND including bilateral retinal detachment, microphthalmia, atrophic irides, corneal opacification, and cataracts, but no symptoms of microcephaly, intellectual disability, and epilepsy. This familial study demonstrates that a deficiency in one of two MAO genes may not lead to psychomotor delay, and deletion of EFHC2 may not cause epilepsy. Our observations provide new information on the genotype-phenotype relations of MAOA/B and EFHC2 genes involved in the contiguous deletions of ND.
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Affiliation(s)
- Bei Jia
- The Center for Prenatal and Hereditary DiseaseDiagnosis,Department of Obstetrics and Gynecology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, People's Republic of China.
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Wnt, RSPO and Hippo Signalling in the Intestine and Intestinal Stem Cells. Genes (Basel) 2018; 9:genes9010020. [PMID: 29316729 PMCID: PMC5793173 DOI: 10.3390/genes9010020] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 12/22/2017] [Accepted: 12/28/2017] [Indexed: 01/07/2023] Open
Abstract
In this review, we address aspects of Wnt, R-Spondin (RSPO) and Hippo signalling, in both healthy and transformed intestinal epithelium. In intestinal stem cells (ISCs), the Wnt pathway is essential for intestinal crypt formation and renewal, whereas RSPO-mediated signalling mainly affects ISC numbers. In human colorectal cancer (CRC), aberrant Wnt signalling is the driving mechanism initiating this type of neoplasia. The signalling role of the RSPO-binding transmembrane proteins, the leucine-rich-repeat-containing G-protein-coupled receptors (LGRs), is possibly more pleiotropic and not only limited to the enhancement of Wnt signalling. There is growing evidence for multiple crosstalk between Hippo and Wnt/β-catenin signalling. In the ON state, Hippo signalling results in serine/threonine phosphorylation of Yes-associated protein (YAP1) and tafazzin (TAZ), promoting formation of the β-catenin destruction complex. In contrast, YAP1 or TAZ dephosphorylation (and YAP1 methylation) results in β-catenin destruction complex deactivation and β-catenin nuclear localization. In the Hippo OFF state, YAP1 and TAZ are engaged with the nuclear β-catenin and participate in the β-catenin-dependent transcription program. Interestingly, YAP1/TAZ are dispensable for intestinal homeostasis; however, upon Wnt pathway hyperactivation, the proteins together with TEA domain (TEAD) transcription factors drive the transcriptional program essential for intestinal cell transformation. In addition, in many CRC cells, YAP1 phosphorylation by YES proto-oncogene 1 tyrosine kinase (YES1) leads to the formation of a transcriptional complex that includes YAP1, β-catenin and T-box 5 (TBX5) DNA-binding protein. YAP1/β-catenin/T-box 5-mediated transcription is necessary for CRC cell proliferation and survival. Interestingly, dishevelled (DVL) appears to be an important mediator involved in both Wnt and Hippo (YAP1/TAZ) signalling and some of the DVL functions were assigned to the nuclear DVL pool. Wnt ligands can trigger alternative signalling that directly involves some of the Hippo pathway components such as YAP1, TAZ and TEADs. By upregulating Wnt pathway agonists, the alternative Wnt signalling can inhibit the canonical Wnt pathway activity.
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Tortelote GG, Reis RR, de Almeida Mendes F, Abreu JG. Complexity of the Wnt/β‑catenin pathway: Searching for an activation model. Cell Signal 2017; 40:30-43. [PMID: 28844868 DOI: 10.1016/j.cellsig.2017.08.008] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 08/08/2017] [Accepted: 08/23/2017] [Indexed: 12/13/2022]
Abstract
Wnt signaling refers to a conserved signaling pathway, widely studied due to its roles in cellular communication, cell fate decisions, development and cancer. However, the exact mechanism underlying inhibition of the GSK phosphorylation towards β-catenin and activation of the pathway after biding of Wnt ligand to its cognate receptors at the plasma membrane remains unclear. Wnt target genes are widely spread over several animal phyla. They participate in a plethora of functions during the development of an organism, from axial specification, gastrulation and organogenesis all the way to regeneration and repair in adults. Temporal and spatial oncogenetic re-activation of Wnt signaling almost certainly leads to cancer. Wnt signaling components have been extensively studied as possible targets in anti-cancer therapies. In this review we will discuss one of the most intriguing questions in this field, that is how β-catenin, a major component in this pathway, escapes the destruction complex, gets stabilized in the cytosol and it is translocated to the nucleus where it acts as a co-transcription factor. Four major models have evolved during the past 20years. We dissected each of them along with current views and future perspectives on this pathway. This review will focus on the molecular mechanisms by which Wnt proteins modulate β-catenin cytoplasmic levels and the relevance of this pathway for the development and cancer.
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Affiliation(s)
- Giovane G Tortelote
- Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Renata R Reis
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fabio de Almeida Mendes
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jose Garcia Abreu
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
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Dailey WA, Drenser KA, Wong SC, Cheng M, Vercellone J, Roumayah KK, Feeney EV, Deshpande M, Guzman AE, Trese M, Mitton KP. Norrin treatment improves ganglion cell survival in an oxygen-induced retinopathy model of retinal ischemia. Exp Eye Res 2017; 164:129-138. [PMID: 28823941 DOI: 10.1016/j.exer.2017.08.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 07/17/2017] [Accepted: 08/14/2017] [Indexed: 12/25/2022]
Abstract
Treatment of a mouse model of oxygen-induced retinopathy (OIR) with recombinant human Norrin (Norrie Disease Protein, gene: NDP) accelerates regrowth of the microvasculature into central ischemic regions of the neural retina, which are generated after treatment with 75% oxygen. While this reduces the average duration and severity of ischemia overall, we do not know if this accelerated recovery of the microvasculature results in any significant survival of retinal ganglion cells (RGCs). The purpose of this study was to investigate ganglion cell survival with and without the intravitreal injection of Norrin in the murine model of oxygen induced retinopathy (OIR), using two strains of mice: C57BL/6J and Thy1-YFP mice. Intravitreal injections of Norrin or vehicle were done after five days of exposure to 75% oxygen from ages P7 to P12. The C57BL/J mice were followed by Spectral-Domain Optical Coherence Tomography (SD-OCT), and the average nerve fiber layer (NFL) and inner-plexiform layer (IPL) thicknesses were measured at twenty-four locations per retina at P42. Additionally, some C57BL/J retinas were flat mounted and immunostained for the RGC marker, Brn3a, to compare the population density of surviving retinal ganglion cells. Using homozygous Thy1-YFP mice, single intrinsically fluorescent RGCs were imaged in live animals with a Micron-III imaging system at ages P21, 28 and P42. The relative percentage of YFP-fluorescent RGCs with dendritic arbors were compared. At age P42, the NFL was thicker in Norrin-injected OIR eyes, 14.4 μm, compared to Vehicle-injected OIR eyes, 13.3 μm (p = 0.01). In the superior retina, the average thickness of the IPL was greater in Norrin-injected OIR eyes, 37.7 μm, compared to Vehicle-injected OIR eyes, 34.6 μm (p = 0.04). Retinas from Norrin injected OIR mice had significantly more surviving RGCs (p = 0.03) than vehicle-injected mice. Based upon NFL thickness and counts of RGCs, we conclude that Norrin treatment, early in the ischemic phase, increased the relative population density of surviving RGCs in the central retinas of OIR mice.
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Affiliation(s)
- Wendy A Dailey
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States
| | - Kimberly A Drenser
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States; Associated Retinal Consultants, Novi, MI, United States
| | - Sui Chien Wong
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States
| | - Mei Cheng
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States
| | - Joseph Vercellone
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States
| | - Kevin K Roumayah
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States
| | - Erin V Feeney
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States
| | - Mrinalini Deshpande
- Control of Gene Expression Laboratory, Eye Research Institute, Oakland University, United States
| | - Alvaro E Guzman
- Control of Gene Expression Laboratory, Eye Research Institute, Oakland University, United States
| | - Michael Trese
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States; Associated Retinal Consultants, Novi, MI, United States
| | - Kenneth P Mitton
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States; Control of Gene Expression Laboratory, Eye Research Institute, Oakland University, United States.
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Norrin-induced Frizzled4 endocytosis and endo-lysosomal trafficking control retinal angiogenesis and barrier function. Nat Commun 2017; 8:16050. [PMID: 28675177 PMCID: PMC5500887 DOI: 10.1038/ncomms16050] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 05/17/2017] [Indexed: 02/06/2023] Open
Abstract
Angiogenesis and blood–brain barrier formation are required for normal central nervous system (CNS) function. Both processes are controlled by Wnt or Norrin (NDP) ligands, Frizzled (FZD) receptors, and β-catenin-dependent signalling in vascular endothelial cells. In the retina, FZD4 and the ligand NDP are critical mediators of signalling and are mutated in familial exudative vitreoretinopathy. Here, we report that NDP is a potent trigger of FZD4 ubiquitination and induces internalization of the NDP receptor complex into the endo-lysosomal compartment. Inhibition of ubiquitinated cargo transport through the multivesicular body (MVB) pathway using a dominant negative ESCRT (endosomal sorting complexes required for transport) component VPS4 EQ strongly impairs NDP/FZD4 signalling in vitro and recapitulates CNS angiogenesis and blood-CNS-barrier defects caused by impaired vascular β-catenin signalling in mice. These findings provide evidence for an important role of FZD4 endocytosis in NDP/FZD4 signalling and in CNS vascular biology and disease. Multiple mechanisms regulate Wnt/ß-catenin signalling. Zhang et al. describe a novel regulatory pathway and show that the activator of canonical Wnt signalling, Norrin, triggers endocytosis of its receptor Frizzled4 by promoting Frizzled4 ubiquitination.
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Abstract
Leucine-rich repeat-containing G-protein-coupled receptor 4 (LGR4) is produced in a broad spectrum of mouse embryonic and adult tissues and its deficiency results in embryonal or perinatal lethality. The LGR4 function was mainly related to its potentiation of canonical Wnt signaling; however, several recent studies associate LGR4 with additional signaling pathways. To obtain a suitable tool for studying the signaling properties of Lgr4, we generated a tagged variant of the Lgr4 receptor using gene targeting in the mouse oocyte. The modified Lgr4 allele expresses the Lgr4 protein fused with a triple hemagglutinin (3HA) tag located at the extracellular part of the protein. The allele is fully functional, enabling tracking of Lgr4 expression in the mouse tissues. We also show that via surface labeling, the 3HA tag allows direct isolation and analysis of living Lgr4-positive cells obtained from the small intestinal crypts. Finally, the HA tag-specific antibody can be employed to characterize the biochemical features of Lgr4 and to identify possible biding partners of the protein in cells derived from various mouse tissues.
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30
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Snyder JC, Rochelle LK, Ray C, Pack TF, Bock CB, Lubkov V, Lyerly HK, Waggoner AS, Barak LS, Caron MG. Inhibiting clathrin-mediated endocytosis of the leucine-rich G protein-coupled receptor-5 diminishes cell fitness. J Biol Chem 2017; 292:7208-7222. [PMID: 28275053 PMCID: PMC5409487 DOI: 10.1074/jbc.m116.756635] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 03/08/2017] [Indexed: 12/19/2022] Open
Abstract
The leucine-rich G protein-coupled receptor-5 (LGR5) is expressed in adult tissue stem cells of many epithelia, and its overexpression is negatively correlated with cancer prognosis. LGR5 potentiates WNT/β-catenin signaling through its unique constitutive internalization property that clears negative regulators of the WNT-receptor complex from the membrane. However, both the mechanism and physiological relevance of LGR5 internalization are unclear. Therefore, a natural product library was screened to discover LGR5 internalization inhibitors and gain mechanistic insight into LGR5 internalization. The plant lignan justicidin B blocked the constitutive internalization of LGR5. Justicidin B is structurally similar to more potent vacuolar-type H+-ATPase inhibitors, which all inhibited LGR5 internalization by blocking clathrin-mediated endocytosis. We then tested the physiological relevance of LGR5 internalization blockade in vivo A LGR5-rainbow (LBOW) mouse line was engineered to express three different LGR5 isoforms along with unique fluorescent protein lineage reporters in the same mouse. In this manner, the effects of each isoform on cell fate can be simultaneously assessed through simple fluorescent imaging for each lineage reporter. LBOW mice express three different forms of LGR5, a wild-type form that constitutively internalizes and two mutant forms whose internalization properties have been compromised by genetic perturbations within the carboxyl-terminal tail. LBOW was activated in the intestinal epithelium, and a year-long lineage-tracing course revealed that genetic blockade of LGR5 internalization diminished cell fitness. Together these data provide proof-of-concept genetic evidence that blocking the clathrin-mediated endocytosis of LGR5 could be used to pharmacologically control cell behavior.
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Affiliation(s)
| | | | | | | | - Cheryl B Bock
- Duke Cancer Institute Transgenic Core, Duke University Medical Center, Durham, North Carolina 27712 and
| | | | | | - Alan S Waggoner
- Department of Biological Sciences and Molecular Biosensor and Imaging Center, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
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Zhang M, Zhang P, Liu Y, Lv L, Zhang X, Liu H, Zhou Y. RSPO3-LGR4 Regulates Osteogenic Differentiation Of Human Adipose-Derived Stem Cells Via ERK/FGF Signalling. Sci Rep 2017; 7:42841. [PMID: 28220828 PMCID: PMC5318871 DOI: 10.1038/srep42841] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 01/16/2017] [Indexed: 01/09/2023] Open
Abstract
The four R-spondins (RSPOs) and their three related receptors, LGR4, 5 and 6, have emerged as a major ligand-receptor system with critical roles in development and stem cell survival. However, the exact roles of the RSPO-LGR system in osteogenesis remain largely unknown. In the present study, we showed that RSPO3-shRNA increased the osteogenic potential of human adipose-derived stem cells (hASCs) significantly. Mechanistically, we demonstrated that RSPO3 is a negative regulator of ERK/FGF signalling. We confirmed that inhibition of the ERK1/2 signalling pathway blocked osteogenic differentiation in hASCs, and the increased osteogenic capacity observed after RSPO3 knockdown in hASCs was reversed by inhibition of ERK signalling. Further, silencing of LGR4 inhibited the activity of ERK signalling and osteogenic differentiation of hASCs. Most importantly, we found that loss of LGR4 abrogated RSPO3-regulated osteogenesis and RSPO3-induced ERK1/2 signalling inhibition. Collectively, our data show that ERK signalling works downstream of LGR4 and RSPO3 regulates osteoblastic differentiation of hASCs possibly via the LGR4-ERK signalling.
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Affiliation(s)
- Min Zhang
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, 100081, China.,National Engineering Lab for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Ping Zhang
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, 100081, China.,National Engineering Lab for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Yunsong Liu
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, 100081, China.,National Engineering Lab for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Longwei Lv
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, 100081, China.,National Engineering Lab for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Xiao Zhang
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, 100081, China.,National Engineering Lab for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Hao Liu
- National Engineering Lab for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, 100081, China.,Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Yongsheng Zhou
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, 100081, China.,National Engineering Lab for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, 100081, China
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Abstract
Wnt-signaling, a ubiquitous pathway that directs differentiation, cell polarity, and tissue specificity, has been implicated as an important gene-expression pathway in retinal development. An increasing body of evidence supports the importance of Wnt-signaling, and specifically, norrin-mediated Wnt-signaling in retinal development and retinal maintenance. Gene mutations affecting the Wnt-signaling pathways result in a variety of inherited vitreoretinopathies. Additionally, there is growing evidence that prematurity and associated retinopathy are associated with alterations in the Wnt-signaling pathways. Further investigations may allow for improved diagnoses, management, and therapies in the future.
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Abstract
The discovery of the transforming growth factor β (TGF-β) family ligands and the realization that their bioactivities need to be tightly controlled temporally and spatially led to intensive research that has identified a multitude of extracellular modulators of TGF-β family ligands, uncovered their functions in developmental and pathophysiological processes, defined the mechanisms of their activities, and explored potential modulator-based therapeutic applications in treating human diseases. These studies revealed a diverse repertoire of extracellular and membrane-associated molecules that are capable of modulating TGF-β family signals via control of ligand availability, processing, ligand-receptor interaction, and receptor activation. These molecules include not only soluble ligand-binding proteins that were conventionally considered as agonists and antagonists of TGF-β family of growth factors, but also extracellular matrix (ECM) proteins and proteoglycans that can serve as "sink" and control storage and release of both the TGF-β family ligands and their regulators. This extensive network of soluble and ECM modulators helps to ensure dynamic and cell-specific control of TGF-β family signals. This article reviews our knowledge of extracellular modulation of TGF-β growth factors by diverse proteins and their molecular mechanisms to regulate TGF-β family signaling.
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Affiliation(s)
- Chenbei Chang
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294
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Musada GR, Jalali S, Hussain A, Chururu AR, Gaddam PR, Chakrabarti S, Kaur I. Mutation spectrum of the Norrie disease pseudoglioma (NDP) gene in Indian patients with FEVR. Mol Vis 2016; 22:491-502. [PMID: 27217716 PMCID: PMC4872281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 05/13/2016] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Mutations in the Norrie disease pseudoglioma (NDP; Xp11.3) gene have been involved in retinal blood vessel formation and neural differentiation and are implicated in familial exudative vitreoretinopathy (FEVR) cases. However, the role of the gene has not been explored in the Indian context. Thus, this study was designed to understand the involvement of NDP among Indian patients with FEVR. METHODS The study cohort comprised 225 subjects, including unrelated patients with FEVR (n = 110) and ethnically matched healthy subjects (n = 115) recruited from a tertiary eye care center in India. The entire coding regions, intron-exon boundaries, along with the 5' and 3' untranslated regions of NDP were screened with resequencing following standard protocols. The spectrum of the observed variants was analyzed in conjunction with data available from other populations. RESULTS Eight potentially pathogenic mutations (p.His4ArgfsX21, p.Asp23GlufsX9, p.Ile48ValfsX55, p.His50Asp, p.Ser57*, p.Gly113Asp, p.Arg121Gln, and p.Cys126Arg, including five novel ones), were observed in the coding region of the NDP gene in ten unrelated FEVR probands (9%). The novel changes were not observed in the control subjects and were unavailable in the dbSNP, ESP5400, NIEHS95, and ExAC databases. All probands with NDP mutations exhibited classical features of the disease as observed among patients with FEVR worldwide. CONCLUSIONS This is perhaps the first study to demonstrate the involvement of NDP among patients with Indian FEVR that further expands its mutation spectrum. The data generated could have broad implications in genetic counseling, disease management, and early intervention for a better prognosis in FEVR.
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Affiliation(s)
- Ganeswara Rao Musada
- Kallam Anji Reddy Molecular Genetics Laboratory, Brien Holden Eye Research Centre, BHERC, L V Prasad Eye Institute, Hyderabad, India
| | - Subhadra Jalali
- Smt. Kanuri Santhamma Centre for Vitreo Retinal Diseases, L V Prasad Eye Institute, Hyderabad, India
| | - Anjli Hussain
- Smt. Kanuri Santhamma Centre for Vitreo Retinal Diseases, L V Prasad Eye Institute, Hyderabad, India
| | | | | | - Subhabrata Chakrabarti
- Kallam Anji Reddy Molecular Genetics Laboratory, Brien Holden Eye Research Centre, BHERC, L V Prasad Eye Institute, Hyderabad, India
| | - Inderjeet Kaur
- Kallam Anji Reddy Molecular Genetics Laboratory, Brien Holden Eye Research Centre, BHERC, L V Prasad Eye Institute, Hyderabad, India
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35
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LGR4 is a receptor for RANKL and negatively regulates osteoclast differentiation and bone resorption. Nat Med 2016; 22:539-46. [PMID: 27064449 DOI: 10.1038/nm.4076] [Citation(s) in RCA: 243] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 03/05/2016] [Indexed: 12/16/2022]
Abstract
Tumor necrosis factor (TNF) superfamily member 11 (TNFSF11, also known as RANKL) regulates multiple physiological or pathological functions, including osteoclast differentiation and osteoporosis. TNFRSF11A (also called RANK) is considered to be the sole receptor for RANKL. Herein we report that leucine-rich repeat-containing G-protein-coupled receptor 4 (LGR4, also called GPR48) is another receptor for RANKL. LGR4 competes with RANK to bind RANKL and suppresses canonical RANK signaling during osteoclast differentiation. RANKL binding to LGR4 activates the Gαq and GSK3-β signaling pathway, an action that suppresses the expression and activity of nuclear factor of activated T cells, cytoplasmic, calcineurin-dependent 1 (NFATC1) during osteoclastogenesis. Both whole-body (Lgr4(-/-)) and monocyte conditional knockout mice of Lgr4 (Lgr4 CKO) exhibit osteoclast hyperactivation (including elevation of osteoclast number, surface area, and size) and increased bone erosion. The soluble LGR4 extracellular domain (ECD) binds RANKL and inhibits osteoclast differentiation in vivo. Moreover, LGR4-ECD therapeutically abrogated RANKL-induced bone loss in three mouse models of osteoporosis. Therefore, LGR4 acts as a second RANKL receptor that negatively regulates osteoclast differentiation and bone resorption.
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Snyder JC, Pack TF, Rochelle LK, Chakraborty SK, Zhang M, Eaton AW, Bai Y, Ernst LA, Barak LS, Waggoner AS, Caron MG. A rapid and affordable screening platform for membrane protein trafficking. BMC Biol 2015; 13:107. [PMID: 26678094 PMCID: PMC4683952 DOI: 10.1186/s12915-015-0216-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 12/02/2015] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Membrane proteins regulate a diversity of physiological processes and are the most successful class of targets in drug discovery. However, the number of targets adequately explored in chemical space and the limited resources available for screening are significant problems shared by drug-discovery centers and small laboratories. Therefore, a low-cost and universally applicable screen for membrane protein trafficking was developed. RESULTS This high-throughput screen (HTS), termed IRFAP-HTS, utilizes the recently described MarsCy1-fluorogen activating protein and the near-infrared and membrane impermeant fluorogen SCi1. The cell surface expression of MarsCy1 epitope-tagged receptors can be visualized by simple addition of SCi1. User-friendly, rapid, and quantitative detection occurs on a standard infrared western-blotting scanner. The reliability and robustness of IRFAP-HTS was validated by confirming human vasopressin-2 receptor and dopamine receptor-2 trafficking in response to agonist or antagonist. The IRFAP-HTS screen was deployed against the leucine-rich G protein-coupled receptor-5 (Lgr5). Lgr5 is expressed in stem cells, modulates Wnt/ß-catenin signaling, and is therefore a promising drug target. However, small molecule modulators have yet to be reported. The constitutive internalization of Lgr5 appears to be one primary mode through which its function is regulated. Therefore, IRFAP-HTS was utilized to screen 11,258 FDA-approved and drug-like small molecules for those that antagonize Lgr5 internalization. Glucocorticoids were found to potently increase Lgr5 expression at the plasma membrane. CONCLUSION The IRFAP-HTS platform provides a versatile solution for screening more targets with fewer resources. Using only a standard western-blotting scanner, we were able to screen 5,000 compounds per hour in a robust and quantitative assay. Multi-purposing standardly available laboratory equipment eliminates the need for idiosyncratic and more expensive high-content imaging systems. The modular and user-friendly IRFAP-HTS is a significant departure from current screening platforms. Small laboratories will have unprecedented access to a robust and reliable screening platform and will no longer be limited by the esoteric nature of assay development, data acquisition, and post-screening analysis. The discovery of glucocorticoids as modulators for Lgr5 trafficking confirms that IRFAP-HTS can accelerate drug-discovery and drug-repurposing for even the most obscure targets.
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Affiliation(s)
- Joshua C Snyder
- Departments of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Thomas F Pack
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Lauren K Rochelle
- Departments of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Subhasish K Chakraborty
- Molecular Biosensor and Imaging Center, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Ming Zhang
- Department of Biology, Molecular Biosensor and Imaging Center, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Andrew W Eaton
- Departments of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Yushi Bai
- Departments of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Lauren A Ernst
- Molecular Biosensor and Imaging Center, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Larry S Barak
- Departments of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Alan S Waggoner
- Department of Biology, Molecular Biosensor and Imaging Center, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Marc G Caron
- Departments of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA. .,Departments of Medicine and Neurobiology, Duke University Medical Center, Durham, NC, 27710, USA.
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The Intracellular Loop 2 F328S Frizzled-4 Mutation Implicated in Familial Exudative Vitreoretinopathy Impairs Dishevelled Recruitment. J Mol Signal 2015; 10:5. [PMID: 27096003 PMCID: PMC4831297 DOI: 10.5334/1750-2187-10-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Familial exudative vitreoretinopathy (FEVR) is a disease state characterized by aberrant retinal angiogenesis. Norrin-induced activation of Frizzled-4 (Fz4) has a major role in regulating beta-catenin levels in the eye that, in turn, modulate the blood retina barrier (BRB). Here we gain insight on the basis of the pathology of a FEVR implicated F328S Fz4 mutant by study. The receptor exhibits a substantially reduced ability to activate Lef/Tcf-dependent transcription. This impaired activation correlates with a decreased ability to stabilize and recruit Dishevelled-2 (Dvl2) to the cell surface. Aromaticity at position 328 of the intracellular loop 2 (iloop2) is revealed similarly as a prerequisite for Dvl2 recruitment to the Fz4. This aromaticity at 328 enables normal Norrin-induced canonical activation. The corresponding position in iloop2 of other Frizzleds likely functions in Dvl recruitment.
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38
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Janssen R, Schönauer A, Weber M, Turetzek N, Hogvall M, Goss GE, Patel NH, McGregor AP, Hilbrant M. The evolution and expression of panarthropod frizzled genes. Front Ecol Evol 2015. [DOI: 10.3389/fevo.2015.00096] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Snyder JC, Rochelle LK, Marion S, Lyerly HK, Barak LS, Caron MG. Lgr4 and Lgr5 drive the formation of long actin-rich cytoneme-like membrane protrusions. J Cell Sci 2015; 128:1230-40. [PMID: 25653388 PMCID: PMC4359926 DOI: 10.1242/jcs.166322] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 01/27/2015] [Indexed: 01/06/2023] Open
Abstract
Embryonic development and adult tissue homeostasis require precise information exchange between cells and their microenvironment to coordinate cell behavior. A specialized class of ultra-long actin-rich filopodia, termed cytonemes, provides one mechanism for this spatiotemporal regulation of extracellular cues. We provide here a mechanism whereby the stem-cell marker Lgr5, and its family member Lgr4, promote the formation of cytonemes. Lgr4- and Lgr5-induced cytonemes exceed lengths of 80 µm, are generated through stabilization of nascent filopodia from an underlying lamellipodial-like network and functionally provide a pipeline for the transit of signaling effectors. As proof-of-principle, we demonstrate that Lgr5-induced cytonemes act as conduits for cell signaling by demonstrating that the actin motor and filopodial cargo carrier protein myosin X (Myo10) and the G-protein-coupled receptor (GPCR) signaling effector β-arrestin-2 (Arrb2) transit into cytonemes. This work delineates a biological function for Lgr4 and Lgr5 and provides the rationale to fully investigate Lgr4 and Lgr5 function and cytonemes in mammalian stem cell and cancer stem cell behavior.
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Affiliation(s)
- Joshua C Snyder
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Lauren K Rochelle
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Sébastien Marion
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - H Kim Lyerly
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Larry S Barak
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Marc G Caron
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
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40
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Yu J, Virshup D. Updating the Wnt pathways. Biosci Rep 2014; 34:e00142. [PMID: 25208913 PMCID: PMC4201215 DOI: 10.1042/bsr20140119] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 09/05/2014] [Accepted: 09/11/2014] [Indexed: 12/12/2022] Open
Abstract
In the three decades since the discovery of the Wnt1 proto-oncogene in virus-induced mouse mammary tumours, our understanding of the signalling pathways that are regulated by the Wnt proteins has progressively expanded. Wnts are involved in an complex signalling network that governs multiple biological processes and cross-talk with multiple additional signalling cascades, including the Notch, FGF (fibroblast growth factor), SHH (Sonic hedgehog), EGF (epidermal growth factor) and Hippo pathways. The Wnt signalling pathway also illustrates the link between abnormal regulation of the developmental processes and disease manifestation. Here we provide an overview of Wnt-regulated signalling cascades and highlight recent advances. We focus on new findings regarding the dedicated Wnt production and secretion pathway with potential therapeutic targets that might be beneficial for patients with Wnt-related diseases.
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Key Words
- adenomatous polyposis coli
- planar cell polarity (pcp)
- wnt
- apc, adenomatous polyposis coli
- bar, bin-amphiphysin-rvs
- cbp, creb (camp response element-binding)-binding protein
- cop, coat protein complex
- crd, cysteine-rich domain
- ctd, c-terminal domain
- ck1α, casein kinase 1 α
- er, endoplasmic reticulum fap, familial adenomatous polyposis
- fdh, focal dermal hypoplasia
- gsk3β, glycogen synthase kinase 3β
- lef, lymphoid enhancer-binding factor
- lrp, lipoprotein receptor-related protein
- ntd, n-terminal domain
- pcp, planar cell polarity
- porcn, protein porcupine
- ror2, receptor tyrosine kinase-like orphan receptor 2
- rspo, r-spondin
- sfrp, secreted frizzled-related protein
- snx-1, sorting nexin-1
- swim, wingless-interacting molecule
- tcf, t cell-specific factor
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Affiliation(s)
- Jia Yu
- *Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore
| | - David M. Virshup
- *Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore
- †Institute of Medical Biology, A*STAR, Singapore 138648, Singapore
- ‡Department of Biochemistry, National University of Singapore, Singapore 117597, Singapore
- §Department of Pediatrics, Duke University, Durham, NC 27710, U.S.A
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A naturally occurring Lgr4 splice variant encodes a soluble antagonist useful for demonstrating the gonadal roles of Lgr4 in mammals. PLoS One 2014; 9:e106804. [PMID: 25188337 PMCID: PMC4154783 DOI: 10.1371/journal.pone.0106804] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 08/05/2014] [Indexed: 01/10/2023] Open
Abstract
Leucine-rich repeat containing G protein-coupled receptor 4 (LGR4) promotes the Wnt signaling through interaction with R-spondins or norrin. Using PCR amplification from rat ovarian cDNAs, we identified a naturally occurring Lgr4 splice variant encoding only the ectodomain of Lgr4, which was named Lgr4-ED. Lgr4-ED can be detected as a secreted protein in the extracts from rodent and bovine postnatal gonads, suggesting conservation of Lgr4-ED in mammals. Recombinant Lgr4-ED purified from the conditioned media of transfected 293T cells was found to dose-dependently inhibit the LGR4-mediated Wnt signaling induced by RSPO2 or norrin, suggesting that it is capable of ligand absorption and could have a potential role as an antagonist. Intraperitoneal injection of purified recombinant Lgr4-ED into newborn mice was found to significantly decrease the testicular expression of estrogen receptor alpha and aquaporin 1, which is similar to the phenotype found in Lgr4-null mice. Administration of recombinant Lgr4-ED to superovulated female rats can also decrease the expression of estrogen receptor alpha, aquaporin 1, LH receptor and other key steroidogenic genes as well as bring about the suppression of progesterone production. Thus, these findings suggest that endogenously expressed Lgr4-ED may act as an antagonist molecule and help to fine-tune the R-spondin/norrin-mediated Lgr4-Wnt signaling during gonadal development.
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Zhou Y, Wang Y, Tischfield M, Williams J, Smallwood PM, Rattner A, Taketo MM, Nathans J. Canonical WNT signaling components in vascular development and barrier formation. J Clin Invest 2014; 124:3825-46. [PMID: 25083995 DOI: 10.1172/jci76431] [Citation(s) in RCA: 223] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 06/12/2014] [Indexed: 01/10/2023] Open
Abstract
Canonical WNT signaling is required for proper vascularization of the CNS during embryonic development. Here, we used mice with targeted mutations in genes encoding canonical WNT pathway members to evaluate the exact contribution of these components in CNS vascular development and in specification of the blood-brain barrier (BBB) and blood-retina barrier (BRB). We determined that vasculature in various CNS regions is differentially sensitive to perturbations in canonical WNT signaling. The closely related WNT signaling coreceptors LDL receptor-related protein 5 (LRP5) and LRP6 had redundant functions in brain vascular development and barrier maintenance; however, loss of LRP5 alone dramatically altered development of the retinal vasculature. The BBB in the cerebellum and pons/interpeduncular nuclei was highly sensitive to decrements in canonical WNT signaling, and WNT signaling was required to maintain plasticity of barrier properties in mature CNS vasculature. Brain and retinal vascular defects resulting from ablation of Norrin/Frizzled4 signaling were ameliorated by stabilizing β-catenin, while inhibition of β-catenin-dependent transcription recapitulated the vascular development and barrier defects associated with loss of receptor, coreceptor, or ligand, indicating that Norrin/Frizzled4 signaling acts predominantly through β-catenin-dependent transcriptional regulation. Together, these data strongly support a model in which identical or nearly identical canonical WNT signaling mechanisms mediate neural tube and retinal vascularization and maintain the BBB and BRB.
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Roch GJ, Sherwood NM. Glycoprotein hormones and their receptors emerged at the origin of metazoans. Genome Biol Evol 2014; 6:1466-79. [PMID: 24904013 PMCID: PMC4079206 DOI: 10.1093/gbe/evu118] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The cystine knot growth factor (CKGF) superfamily includes important secreted developmental regulators, including the families of transforming growth factor beta, nerve growth factor, platelet-derived growth factor, and the glycoprotein hormones (GPHs). The evolutionary origin of the GPHs and the related invertebrate bursicon hormone, and their characteristic receptors, contributes to an understanding of the endocrine system in metazoans. Using a sensitive search method with hidden Markov models, we identified homologs of the hormones and receptors, along with the closely related bone morphogenetic protein (BMP) antagonists in basal metazoans. In sponges and a comb jelly, cystine knot hormones (CKHs) with mixed features of GPHs, bursicon, and BMP antagonists were identified using primary sequence and phylogenetic analysis. Also, we identified potential receptors for these CKHs, leucine-rich repeat-containing G protein-coupled receptors (LGRs), in the same species. Cnidarians, such as the sea anemone, coral, and hydra, diverged later in metazoan evolution and appear to have duplicated and differentiated CKH-like peptides resulting in bursicon/GPH-like peptides and several BMP antagonists: Gremlin (Grem), sclerostin domain containing (SOSD), neuroblastoma suppressor of tumorigenicity 1 (NBL1), and Norrie disease protein. An expanded cnidarian LGR group also evolved, including receptors for GPH and bursicon. With the appearance of bilaterians, a separate GPH (thyrostimulin) along with bursicon and BMP antagonists were present. Synteny indicates that the GPHs, Grem, and SOSD have been maintained in a common gene neighborhood throughout much of metazoan evolution. The stable and highly conserved CKGFs are not identified in nonmetazoan organisms but are established with their receptors in the basal metazoans, becoming critical to growth, development, and regulation in all animals.
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Affiliation(s)
- Graeme J Roch
- Department of Biology, University of Victoria, British Columbia, Canada
| | - Nancy M Sherwood
- Department of Biology, University of Victoria, British Columbia, Canada
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44
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Scopelliti A, Cordero JB, Diao F, Strathdee K, White BH, Sansom OJ, Vidal M. Local control of intestinal stem cell homeostasis by enteroendocrine cells in the adult Drosophila midgut. Curr Biol 2014; 24:1199-211. [PMID: 24814146 PMCID: PMC4046228 DOI: 10.1016/j.cub.2014.04.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 02/27/2014] [Accepted: 04/02/2014] [Indexed: 12/28/2022]
Abstract
BACKGROUND Enteroendocrine cells populate gastrointestinal tissues and are known to translate local cues into systemic responses through the release of hormones into the bloodstream. RESULTS Here we report a novel function of enteroendocrine cells acting as local regulators of intestinal stem cell (ISC) proliferation through modulation of the mesenchymal stem cell niche in the Drosophila midgut. This paracrine signaling acts to constrain ISC proliferation within the epithelial compartment. Mechanistically, midgut enteroendocrine cells secrete the neuroendocrine hormone Bursicon, which acts-beyond its known roles in development-as a paracrine factor on the visceral muscle (VM). Bursicon binding to its receptor, DLGR2, the ortholog of mammalian leucine-rich repeat-containing G protein-coupled receptors (LGR4-6), represses the production of the VM-derived EGF-like growth factor Vein through activation of cAMP. CONCLUSIONS We therefore identify a novel paradigm in the regulation of ISC quiescence involving the conserved ligand/receptor Bursicon/DLGR2 and a previously unrecognized tissue-intrinsic role of enteroendocrine cells.
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Affiliation(s)
- Alessandro Scopelliti
- The Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Julia B Cordero
- The Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK.
| | - Fengqiu Diao
- Laboratory of Molecular Biology, NIMH, 35 Convent Drive, MSC 4035, Bethesda, MD 20892-4035, USA
| | - Karen Strathdee
- The Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Benjamin H White
- Laboratory of Molecular Biology, NIMH, 35 Convent Drive, MSC 4035, Bethesda, MD 20892-4035, USA
| | - Owen J Sansom
- The Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Marcos Vidal
- The Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK.
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Nolan K, Thompson TB. The DAN family: modulators of TGF-β signaling and beyond. Protein Sci 2014; 23:999-1012. [PMID: 24810382 DOI: 10.1002/pro.2485] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 04/30/2014] [Accepted: 05/01/2014] [Indexed: 01/11/2023]
Abstract
Extracellular binding proteins or antagonists are important factors that modulate ligands in the transforming growth factor (TGF-β) family. While the interplay between antagonists and ligands are essential for developmental and normal cellular processes, their imbalance can lead to the pathology of several disease states. In particular, recent studies have implicated members of the differential screening-selected gene in neuroblastoma (DAN) family in disease such as renal fibrosis, pulmonary arterial hypertension, and reactivation of metastatic cancer stem cells. DAN family members are known to inhibit the bone morphogenetic proteins (BMP) of the TGF-β family. However, unlike other TGF-β antagonist families, DAN family members have roles beyond ligand inhibition and can modulate Wnt and vascular endothelial growth factor (VEGF) signaling pathways. This review describes recent structural and functional advances that have expanded our understanding of DAN family proteins with regards to BMP inhibition and also highlights their emerging roles in the modulation of Wnt and VEGF signaling pathways.
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Affiliation(s)
- Kristof Nolan
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, Ohio, 45267
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Peng WC, de Lau W, Forneris F, Granneman JCM, Huch M, Clevers H, Gros P. Structure of stem cell growth factor R-spondin 1 in complex with the ectodomain of its receptor LGR5. Cell Rep 2014; 3:1885-92. [PMID: 23809763 DOI: 10.1016/j.celrep.2013.06.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 06/11/2013] [Indexed: 12/24/2022] Open
Abstract
Leucine-rich repeat-containing G protein-coupled receptors 4-6 (LGR4-LGR6) are receptors for R-spondins, potent Wnt agonists that exert profound trophic effects on Wnt-driven stem cells compartments. We present crystal structures of a signaling-competent fragment of R-spondin 1 (Rspo1) at a resolution of 2.0 Å and its complex with the LGR5 ectodomain at a resolution of 3.2 Å. Ecto-LGR5 binds Rspo1 at its concave leucine-rich-repeat (LRR) surface, forming a dimeric 2:2 complex. Fully conserved residues on LGR4-LGR6 explain promiscuous binding of R-spondins. A phenylalanine clamp formed by Rspo1 Phe106 and Phe110 pinches Ala190 of LGR5 and is critical for binding. Mutations related to congenital anonychia reduce signaling, but not binding of Rspo1 to LGR5. Furthermore, antibody binding to the extended loop of the C-terminal LRR cap of LGR5 activates signaling in a ligand-independent manner. Thus, our data reveal binding of R-spondins to conserved sites on LGR4-LGR6 and, in analogy to FSHR and related receptors, suggest a direct signaling role for LGR4-LGR6 in addition to its formation of Wnt receptor and coreceptor complexes.
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Affiliation(s)
- Weng Chuan Peng
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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47
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Abstract
Adult stem cells are controlled by an intricate interplay of potent Wnt agonists, antagonists, and anti-antagonists. This review by de Lau et al. focuses on the complex physical and functional interactions of three recently discovered protein families that control stem cell activity by regulating surface expression of Wnt receptors: Lgr5 and its homologs, the E3 ligases Rnf43 and Znrf3, and the secreted R-spondin ligands. Lgr5 was originally discovered as a common Wnt target gene in adult intestinal crypts and colon cancer. It was subsequently identified as an exquisite marker of multiple Wnt-driven adult stem cell types. Lgr5 and its homologs, Lgr4 and Lgr6, constitute the receptors for R-spondins, potent Wnt signal enhancers and stem cell growth factors. The Lgr5/R-spondin complex acts by neutralizing Rnf43 and Znrf3, two transmembrane E3 ligases that remove Wnt receptors from the stem cell surface. Rnf43/Znrf3 are themselves encoded by Wnt target genes and constitute a negative Wnt feedback loop. Thus, adult stem cells are controlled by an intricate interplay of potent Wnt agonists, antagonists, and anti-antagonists.
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Affiliation(s)
- Wim de Lau
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), University Medical Centre Utrecht, 3584 CT Utrecht, The Netherlands
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48
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Yi T, Weng J, Siwko S, Luo J, Li D, Liu M. LGR4/GPR48 inactivation leads to aniridia-genitourinary anomalies-mental retardation syndrome defects. J Biol Chem 2014; 289:8767-80. [PMID: 24519938 DOI: 10.1074/jbc.m113.530816] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
AGR syndrome (the clinical triad of aniridia, genitourinary anomalies, and mental retardation, a subgroup of WAGR syndrome for Wilm's tumor, aniridia, genitourinary anomalies, and mental retardation) is a rare syndrome caused by a contiguous gene deletion in the 11p13-14 region. However, the mechanisms of WAGR syndrome pathogenesis are elusive. In this study we provide evidence that LGR4 (also named GPR48), the only G-protein-coupled receptor gene in the human chromosome 11p12-11p14.4 fragment, is the key gene responsible for the diseases of AGR syndrome. Deletion of Lgr4 in mouse led to aniridia, polycystic kidney disease, genitourinary anomalies, and mental retardation, similar to the pathological defects of AGR syndrome. Furthermore, Lgr4 inactivation significantly increased cell apoptosis and decreased the expression of multiple important genes involved in the development of WAGR syndrome related organs. Specifically, deletion of Lgr4 down-regulated the expression of histone demethylases Jmjd2a and Fbxl10 through cAMP-CREB signaling pathways both in mouse embryonic fibroblast cells and in urinary and reproductive system mouse tissues. Our data suggest that Lgr4, which regulates eye, kidney, testis, ovary, and uterine organ development as well as mental development through genetic and epigenetic surveillance, is a novel candidate gene for the pathogenesis of AGR syndrome.
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Affiliation(s)
- Tingfang Yi
- From the Institute of Biosciences and Technology and Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, Houston, Texas 77030 and
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49
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Rowe ML, Achhala S, Elphick MR. Neuropeptides and polypeptide hormones in echinoderms: new insights from analysis of the transcriptome of the sea cucumber Apostichopus japonicus. Gen Comp Endocrinol 2014; 197:43-55. [PMID: 24345384 DOI: 10.1016/j.ygcen.2013.12.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 12/03/2013] [Accepted: 12/08/2013] [Indexed: 11/17/2022]
Abstract
Echinoderms are of special interest for studies in comparative endocrinology because of their phylogenetic position in the animal kingdom as deuterostomian invertebrates. Furthermore, their pentaradial symmetry as adult animals provides a unique context for analysis of the physiological and behavioral roles of peptide signaling systems. Here we report the first extensive survey of neuropeptide and peptide hormone precursors in a species belonging to the class Holothuroidea. Transcriptome sequence data obtained from the sea cucumber Apostichopus japonicus were analyzed to identify homologs of precursor proteins that have recently been identified in the sea urchin Strongylocentrotus purpuratus (class Echinoidea). A total of 17 precursor proteins have been identified in A. japonicus, including precursors of peptides related to thyrotropin-releasing hormone, pedal peptide/orcokinin-type peptides, AN peptides/tachykinins, luqins, corticotropin-releasing hormone (CRH), GPA2-type glycoprotein hormone subunits and bursicon. In addition, an unusual finding was an A. japonicus calcitonin-type precursor protein (AjCTLPP), the first to be discovered that comprises two calcitonin-like peptides; this contrasts with the products of the alternatively-spliced calcitonin/CGRP gene in vertebrates, which comprise either calcitonin or CGRP. Collectively, the data obtained provide new insights on the evolution and diversity of neuropeptides and polypeptide hormones. Furthermore, because A. japonicus is one of several sea cucumber species that are used for human consumption, our findings may have practical and economic impact by providing a basis for neuroendocrine-based strategies to improve methods of aquaculture.
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Affiliation(s)
- Matthew L Rowe
- Queen Mary University of London, School of Biological & Chemical Sciences, Mile End Road, London E1 4NS, UK
| | - Sufyan Achhala
- Queen Mary University of London, School of Biological & Chemical Sciences, Mile End Road, London E1 4NS, UK
| | - Maurice R Elphick
- Queen Mary University of London, School of Biological & Chemical Sciences, Mile End Road, London E1 4NS, UK.
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Snyder JC, Rochelle LK, Barak LS, Caron MG. The stem cell-expressed receptor Lgr5 possesses canonical and functionally active molecular determinants critical to β-arrestin-2 recruitment. PLoS One 2013; 8:e84476. [PMID: 24386388 PMCID: PMC3873998 DOI: 10.1371/journal.pone.0084476] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 11/14/2013] [Indexed: 01/08/2023] Open
Abstract
Lgr5 is a membrane protein related to G protein-coupled receptors (GPCR)s whose expression identifies stem cells in multiple tissues and is strongly correlated with cancer. Despite the recent identification of endogenous ligands for Lgr5, its mode of signaling remains enigmatic. The ability to couple to G proteins and βarrestins are classical molecular behaviors of GPCRs that have yet to be observed for Lgr5. Therefore, the goal of this study was to determine if Lgr5 can engage a classical GPCR behavior and elucidate the molecular determinants of this process. Structural analysis of Lgr5 revealed several motifs consistent with its ability to recruit βarr2. Among them, a "SSS" serine cluster located at amino acid position 873-875 within the C-terminal tail (C-tail), is in a region consistent with other GPCRs that bind βarr2 with high-affinity. To test its functionality, a ligand-independent βarr2 translocation assay was implemented. We show that Lgr5 recruits βarr2 and that the "SSS" amino acids (873-875) are absolutely critical to this process. We also demonstrate that for full efficacy, this cluster requires other Lgr5 C-tail serines that were previously shown to be important for constitutive and βarr2 independent internalization of Lgr5. These data are proof of principle that a classical GPCR behavior can be manifested by Lgr5. The existence of alternative ligands or missing effectors of Lgr5 that scaffold this classical GPCR behavior and the downstream signaling pathways engaged should be considered. Characterizing Lgr5 signaling will be invaluable for assessing its role in tissue maintenance, repair, and disease.
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Affiliation(s)
- Joshua C. Snyder
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Lauren K. Rochelle
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Larry S. Barak
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Marc G. Caron
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
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