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Jin Y, Cong Q, Gvozdenovic-Jeremic J, Hu J, Zhang Y, Terkeltaub R, Yang Y. Enpp1 inhibits ectopic joint calcification and maintains articular chondrocytes by repressing hedgehog signaling. Development 2018; 145:dev.164830. [PMID: 30111653 DOI: 10.1242/dev.164830] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 07/12/2018] [Indexed: 01/15/2023]
Abstract
The differentiated phenotype of articular chondrocytes of synovial joints needs to be maintained throughout life. Disruption of the articular cartilage, frequently associated with chondrocyte hypertrophy and calcification, is a central feature in osteoarthritis (OA). However, the molecular mechanisms whereby phenotypes of articular chondrocytes are maintained and pathological calcification is inhibited remain poorly understood. Recently, the ecto-enzyme Enpp1, a suppressor of pathological calcification, was reported to be decreased in joint cartilage with OA in both human and mouse, and Enpp1 deficiency causes joint calcification. Here, we found that hedgehog (Hh) signaling activation contributes to ectopic joint calcification in the Enpp1-/- mice. In the Enpp1-/- joints, Hh signaling was upregulated. Further activation of Hh signaling by removing the patched 1 gene in the Enpp1-/- mice enhanced ectopic joint calcification, whereas removing Gli2 partially rescued the ectopic calcification phenotype. In addition, reduction of Gαs in the Enpp1-/- mice enhanced joint calcification, suggesting that Enpp1 inhibits Hh signaling and chondrocyte hypertrophy by activating Gαs-PKA signaling. Our findings provide new insights into the mechanisms underlying Enpp1 regulation of joint integrity.
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Affiliation(s)
- Yunyun Jin
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, MA 02115, USA.,Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Qian Cong
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, MA 02115, USA
| | | | - Jiajie Hu
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, MA 02115, USA
| | - Yiqun Zhang
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, MA 02115, USA
| | - Robert Terkeltaub
- Department of Medicine, Veterans Affairs Healthcare System, University of California San Diego, 111K, 3350 La Jolla Village Dr., San Diego, CA 92161, USA
| | - Yingzi Yang
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, MA 02115, USA
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2
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Kim W, Khan SK, Gvozdenovic-Jeremic J, Kim Y, Dahlman J, Kim H, Park O, Ishitani T, Jho EH, Gao B, Yang Y. Hippo signaling interactions with Wnt/β-catenin and Notch signaling repress liver tumorigenesis. J Clin Invest 2017. [PMID: 27869648 DOI: 10.1172/jci88486.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Malignant tumors develop through multiple steps of initiation and progression, and tumor initiation is of singular importance in tumor prevention, diagnosis, and treatment. However, the molecular mechanism whereby a signaling network of interacting pathways restrains proliferation in normal cells and prevents tumor initiation is still poorly understood. Here, we have reported that the Hippo, Wnt/β-catenin, and Notch pathways form an interacting network to maintain liver size and suppress hepatocellular carcinoma (HCC). Ablation of the mammalian Hippo kinases Mst1 and Mst2 in liver led to rapid HCC formation and activated Yes-associated protein/WW domain containing transcription regulator 1 (YAP/TAZ), STAT3, Wnt/β-catenin, and Notch signaling. Previous work has shown that abnormal activation of these downstream pathways can lead to HCC. Rigorous genetic experiments revealed that Notch signaling forms a positive feedback loop with the Hippo signaling effector YAP/TAZ to promote severe hepatomegaly and rapid HCC initiation and progression. Surprisingly, we found that Wnt/β-catenin signaling activation suppressed HCC formation by inhibiting the positive feedback loop between YAP/TAZ and Notch signaling. Furthermore, we found that STAT3 in hepatocytes is dispensable for HCC formation when mammalian sterile 20-like kinase 1 and 2 (Mst1 and Mst2) were removed. The molecular network we have identified provides insights into HCC molecular classifications and therapeutic developments for the treatment of liver tumors caused by distinct genetic mutations.
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3
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Kim W, Khan SK, Gvozdenovic-Jeremic J, Kim Y, Dahlman J, Kim H, Park O, Ishitani T, Jho EH, Gao B, Yang Y. Hippo signaling interactions with Wnt/β-catenin and Notch signaling repress liver tumorigenesis. J Clin Invest 2016; 127:137-152. [PMID: 27869648 DOI: 10.1172/jci88486] [Citation(s) in RCA: 170] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 10/13/2016] [Indexed: 12/14/2022] Open
Abstract
Malignant tumors develop through multiple steps of initiation and progression, and tumor initiation is of singular importance in tumor prevention, diagnosis, and treatment. However, the molecular mechanism whereby a signaling network of interacting pathways restrains proliferation in normal cells and prevents tumor initiation is still poorly understood. Here, we have reported that the Hippo, Wnt/β-catenin, and Notch pathways form an interacting network to maintain liver size and suppress hepatocellular carcinoma (HCC). Ablation of the mammalian Hippo kinases Mst1 and Mst2 in liver led to rapid HCC formation and activated Yes-associated protein/WW domain containing transcription regulator 1 (YAP/TAZ), STAT3, Wnt/β-catenin, and Notch signaling. Previous work has shown that abnormal activation of these downstream pathways can lead to HCC. Rigorous genetic experiments revealed that Notch signaling forms a positive feedback loop with the Hippo signaling effector YAP/TAZ to promote severe hepatomegaly and rapid HCC initiation and progression. Surprisingly, we found that Wnt/β-catenin signaling activation suppressed HCC formation by inhibiting the positive feedback loop between YAP/TAZ and Notch signaling. Furthermore, we found that STAT3 in hepatocytes is dispensable for HCC formation when mammalian sterile 20-like kinase 1 and 2 (Mst1 and Mst2) were removed. The molecular network we have identified provides insights into HCC molecular classifications and therapeutic developments for the treatment of liver tumors caused by distinct genetic mutations.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/metabolism
- Animals
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/metabolism
- Cell Cycle Proteins
- Hepatocyte Growth Factor/genetics
- Hepatocyte Growth Factor/metabolism
- Hippo Signaling Pathway
- Liver Neoplasms, Experimental/genetics
- Liver Neoplasms, Experimental/metabolism
- Liver Neoplasms, Experimental/pathology
- Mice
- Mice, Knockout
- Phosphoproteins/genetics
- Phosphoproteins/metabolism
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- Receptors, Notch/genetics
- Receptors, Notch/metabolism
- STAT3 Transcription Factor/genetics
- STAT3 Transcription Factor/metabolism
- Serine-Threonine Kinase 3
- Wnt Signaling Pathway
- YAP-Signaling Proteins
- beta Catenin/genetics
- beta Catenin/metabolism
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4
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Shibata Y, Gvozdenovic-Jeremic J, Love J, Kloss B, White JF, Grisshammer R, Tate CG. Optimising the combination of thermostabilising mutations in the neurotensin receptor for structure determination. Biochim Biophys Acta 2013; 1828:1293-301. [PMID: 23337476 DOI: 10.1016/j.bbamem.2013.01.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 01/07/2013] [Accepted: 01/09/2013] [Indexed: 10/27/2022]
Abstract
Conformational thermostabilisation of G protein-coupled receptors is a successful approach for their structure determination. We have recently determined the structure of a thermostabilised neurotensin receptor NTS1 in complex with its peptide agonist and here we describe the strategy for the identification and combination of the 6 thermostabilising mutations essential for crystallisation. First, thermostability assays were performed on a panel of 340 detergent-solubilised Ala/Leu NTS1 mutants and the best 16 thermostabilising mutations were identified. These mutations were combined pair-wise in nearly all combinations (119 out of a possible 120 combinations) and each mutant was expressed and its thermostability was experimentally determined. A theoretical stability score was calculated from the sum of the stabilities measured for each double mutant and applied to develop 24 triple mutants, which in turn led to the construction of 14 quadruple mutants. Use of the thermostability data for the double mutants to predict further mutant combinations resulted in a greater percentage of the triple and quadruple mutants showing improved thermostability than if only the thermostability data for the single mutations was considered. The best quadruple mutant (NTS1-Nag36k) was further improved by including an additional 2 mutations (resulting in NTS1-GW5) that were identified from a complete Ala/Leu scan of Nag36k by testing the thermostability of the mutants in situ in whole bacteria. NTS1-GW5 had excellent stability in short chain detergents and could be readily purified as a homogenous sample that ultimately allowed crystallisation and structure determination.
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Affiliation(s)
- Yoko Shibata
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
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White JF, Noinaj N, Shibata Y, Love J, Kloss B, Xu F, Gvozdenovic-Jeremic J, Shah P, Shiloach J, Tate CG, Grisshammer R. Structure of the agonist-bound neurotensin receptor. Nature 2012; 490:508-13. [PMID: 23051748 PMCID: PMC3482300 DOI: 10.1038/nature11558] [Citation(s) in RCA: 393] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 09/11/2012] [Indexed: 12/11/2022]
Abstract
Neurotensin (NT) is a 13 amino acid peptide that functions as both a neurotransmitter and a hormone through activation of the neurotensin receptor NTS1, a G protein-coupled receptor (GPCR). In the brain, NT modulates activity of dopaminergic systems, opioid-independent analgesia, and the inhibition of food intake, and in the gut NT regulates a range of digestive processes. Here we present the structure at 2.8 Å resolution of NTS1 in an active-like state, bound to NT8-13, the C terminal portion of NT responsible for agonist-induced activation of the receptor. The peptide agonist binds to NTS1 in an extended conformation nearly perpendicular to the membrane plane with the C-terminus oriented towards the receptor core. Our findings provide the first insight into the binding mode of a peptide agonist to a GPCR and may support the development of non-peptide ligands that could be useful in the treatment of neurological disorders, cancer and obesity.
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Affiliation(s)
- Jim F White
- Membrane Protein Structure Function Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland 20852, USA
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6
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Inagaki S, Ghirlando R, White JF, Gvozdenovic-Jeremic J, Northup JK, Grisshammer R. Modulation of the interaction between neurotensin receptor NTS1 and Gq protein by lipid. J Mol Biol 2012; 417:95-111. [PMID: 22306739 DOI: 10.1016/j.jmb.2012.01.023] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 01/09/2012] [Accepted: 01/13/2012] [Indexed: 12/11/2022]
Abstract
Membrane lipids have been implicated to influence the activity of G-protein-coupled receptors (GPCRs). Almost all of our knowledge on the role of lipids on GPCR and G protein function comes from work on the visual pigment rhodopsin and its G protein transducin, which reside in a highly specialized membrane environment. Thus, insight gained from rhodopsin signaling may not be simply translated to other nonvisual GPCRs. Here, we investigated the effect of lipid head group charges on the signal transduction properties of the class A GPCR neurotensin (NT) receptor 1 (NTS1) under defined experimental conditions, using self-assembled phospholipid nanodiscs prepared with the zwitter-ionic lipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), the negatively charged 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (POPG), or a POPC/POPG mixture. A combination of dynamic light scattering and sedimentation velocity showed that NTS1 was monomeric in POPC-, POPC/POPG-, and POPG-nanodiscs. Binding of the agonist NT to NTS1 occurred with similar affinities and was essentially unaffected by the phospholipid composition. In contrast, Gq protein coupling to NTS1 in various lipid nanodiscs was significantly different, and the apparent affinity of Gαq and Gβ(1)γ(1) to activated NTS1 increased with increasing POPG content. NTS1-catalyzed GDP/GTPγS nucleotide exchange at Gαq in the presence of Gβ(1)γ(1) and NT was crucially affected by the lipid type, with exchange rates higher by 1 or 2 orders of magnitude in POPC/POPG- and POPG-nanodiscs, respectively, compared to POPC-nanodiscs. Our data demonstrate that negatively charged lipids in the immediate vicinity of a nonvisual GPCR modulate the G-protein-coupling step.
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Affiliation(s)
- Sayaka Inagaki
- Membrane Protein Structure Function Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Department of Health and Human Services, Rockville, MD 20852, USA
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7
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Zhong Q, Li G, Gvozdenovic-Jeremic J, Greenberg ML. Up-regulation of the cell integrity pathway in saccharomyces cerevisiae suppresses temperature sensitivity of the pgs1Delta mutant. J Biol Chem 2007; 282:15946-53. [PMID: 17426021 DOI: 10.1074/jbc.m701055200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have previously shown that mutants in the cardiolipin (CL) pathway exhibit temperature-sensitive growth defects that are not associated with mitochondrial dysfunction. The pgs1Delta mutant, lacking the first enzyme of the CL pathway, phosphatidylglycerolphosphate synthase (Pgs1p), has a defective cell wall due to decreased beta-1,3-glucan (Zhong, Q., Gvozdenovic-Jeremic, J., Webster, P., Zhou, J., and Greenberg, M. L. (2005) Mol. Biol. Cell 16, 665-675). Disruption of KRE5, a gene involved in cell wall biogenesis, restores beta-1,3-glucan synthesis and suppresses pgs1Delta temperature sensitivity. To gain insight into the mechanisms underlying the cell wall defect in pgs1Delta, we show in the current report that pgs1Delta cells have reduced glucan synthase activity and diminished levels of Fks1p, the glucan synthase catalytic subunit. In addition, activation of Slt2p, the downstream effector of the protein kinase C (PKC)-activated cell integrity pathway, was defective in pgs1Delta. The kre5W1166X suppressor restored Slt2p activation and dramatically increased (>10-fold) mRNA levels of FKS2, the alternate catalytic subunit of glucan synthase, partially restoring glucan synthase activity. Consistent with these results, up-regulation of PKC-Slt2 signaling and overexpression of FKS1 or FKS2 alleviated sensitivity of pgs1Delta to cell wall-perturbing agents and restored growth at elevated temperature. These findings demonstrate that functional Pgs1p is essential for cell wall biogenesis and activation of the PKC-Slt2 signaling pathway.
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Affiliation(s)
- Quan Zhong
- Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202, USA
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8
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Gohil VM, Gvozdenovic-Jeremic J, Schlame M, Greenberg ML. Binding of 10-N-nonyl acridine orange to cardiolipin-deficient yeast cells: Implications for assay of cardiolipin. Anal Biochem 2005; 343:350-2. [PMID: 15963941 DOI: 10.1016/j.ab.2005.04.039] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2005] [Revised: 04/21/2005] [Accepted: 04/25/2005] [Indexed: 11/21/2022]
Affiliation(s)
- Vishal M Gohil
- Department of Biological Science, Wayne State University, Detroit, MI 48202, USA
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9
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Zhong Q, Gvozdenovic-Jeremic J, Webster P, Zhou J, Greenberg ML. Loss of function of KRE5 suppresses temperature sensitivity of mutants lacking mitochondrial anionic lipids. Mol Biol Cell 2004; 16:665-75. [PMID: 15563612 PMCID: PMC545902 DOI: 10.1091/mbc.e04-09-0808] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Disruption of PGS1, which encodes the enzyme that catalyzes the committed step of cardiolipin (CL) synthesis, results in loss of the mitochondrial anionic phospholipids phosphatidylglycerol (PG) and CL. The pgs1Delta mutant exhibits severe growth defects at 37 degrees C. To understand the essential functions of mitochondrial anionic lipids at elevated temperatures, we isolated suppressors of pgs1Delta that grew at 37 degrees C. One of the suppressors has a loss of function mutation in KRE5, which is involved in cell wall biogenesis. The cell wall of pgs1Delta contained markedly reduced beta-1,3-glucan, which was restored in the suppressor. Stabilization of the cell wall with osmotic support alleviated the cell wall defects of pgs1Delta and suppressed the temperature sensitivity of all CL-deficient mutants. Evidence is presented suggesting that the previously reported inability of pgs1Delta to grow in the presence of ethidium bromide was due to defective cell wall integrity, not from "petite lethality." These findings demonstrated that mitochondrial anionic lipids are required for cellular functions that are essential in cell wall biogenesis, the maintenance of cell integrity, and survival at elevated temperature.
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Affiliation(s)
- Quan Zhong
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
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Cotton JC, Pometto AL, Gvozdenovic-Jeremic J. Continuous lactic acid fermentation using a plastic composite support biofilm reactor. Appl Microbiol Biotechnol 2001; 57:626-30. [PMID: 11778870 DOI: 10.1007/s002530100820] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An immobilized-cell biofilm reactor was used for the continuous production of lactic acid by Lactobacillus casei subsp. rhamnosus (ATCC 11443). At Iowa State University, a unique plastic composite support (PCS) that stimulates biofilm formation has been developed. The optimized PCS blend for Lactobacillus contains 50% (wt/wt) agricultural products [35% (wt/wt) ground soy hulls, 5% (wt/wt) soy flour, 5% (wt/wt) yeast extract, 5% (wt/wt) dried bovine albumin, and mineral salts] and 50% (wt/wt) polypropylene (PP) produced by high-temperature extrusion. The PCS tubes have a wall thickness of 3.5 mm, outer diameter of 10.5 mm, and were cut into 10-cm lengths. Six PCS tubes, three rows of two parallel tubes, were bound in a grid fashion to the agitator shaft of a 1.2-1 vessel for a New Brunswick Bioflo 3000 fermentor. PCS stimulates biofilm formation, supplies nutrients to attached and suspended cells, and increases lactic acid production. Biofilm thickness on the PCS tubes was controlled by the agitation speed. The PCS biofilm reactor and PP control reactor achieved optimal average production rates of 9.0 and 5.8 g l(-1) h(-1), respectively, at 0.4 h(-1) dilution rate and 125-rpm agitation with yields of approximately 70%.
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Affiliation(s)
- J C Cotton
- Department of Food Science and Human Nutrition, Center for Crops Utilization Research, Iowa State University, Ames 50011, USA
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