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Humphreys PA, Mancini FE, Ferreira MJS, Woods S, Ogene L, Kimber SJ. Developmental principles informing human pluripotent stem cell differentiation to cartilage and bone. Semin Cell Dev Biol 2022; 127:17-36. [PMID: 34949507 DOI: 10.1016/j.semcdb.2021.11.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 12/14/2022]
Abstract
Human pluripotent stem cells can differentiate into any cell type given appropriate signals and hence have been used to research early human development of many tissues and diseases. Here, we review the major biological factors that regulate cartilage and bone development through the three main routes of neural crest, lateral plate mesoderm and paraxial mesoderm. We examine how these routes have been used in differentiation protocols that replicate skeletal development using human pluripotent stem cells and how these methods have been refined and improved over time. Finally, we discuss how pluripotent stem cells can be employed to understand human skeletal genetic diseases with a developmental origin and phenotype, and how developmental protocols have been applied to gain a better understanding of these conditions.
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Affiliation(s)
- Paul A Humphreys
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK; Department of Mechanical, Aerospace and Civil Engineering, School of Engineering, Faculty of Science and Engineering & Henry Royce Institute, University of Manchester, UK
| | - Fabrizio E Mancini
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Miguel J S Ferreira
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK; Department of Mechanical, Aerospace and Civil Engineering, School of Engineering, Faculty of Science and Engineering & Henry Royce Institute, University of Manchester, UK
| | - Steven Woods
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Leona Ogene
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Susan J Kimber
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK
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Rux D, Helbig K, Han B, Cortese C, Koyama E, Han L, Pacifici M. Primary Cilia Direct Murine Articular Cartilage Tidemark Patterning Through Hedgehog Signaling and Ambulatory Load. J Bone Miner Res 2022; 37:1097-1116. [PMID: 35060644 PMCID: PMC9177786 DOI: 10.1002/jbmr.4506] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 01/01/2022] [Accepted: 01/08/2022] [Indexed: 11/06/2022]
Abstract
Articular cartilage (AC) is essential for body movement but is highly susceptible to degenerative diseases and has poor self-repair capacity. To improve current subpar regenerative treatments, developmental mechanisms of AC should be clarified and, specifically, how its postnatal multizone organization is acquired. Primary cilia are cell surface organelles crucial for mammalian tissue morphogenesis. Although their importance for chondrocyte function is appreciated, their specific roles in postnatal AC morphogenesis remain unclear. To explore these mechanisms, we used a murine conditional loss-of-function approach (Ift88-flox) targeting joint-lineage progenitors (Gdf5Cre) and monitored postnatal knee AC development. Joint formation and growth up to juvenile stages were largely unaffected. However, mature AC (aged 2 months) exhibited disorganized extracellular matrix, decreased aggrecan and collagen II due to reduced gene expression (not increased catabolism), and marked reduction of AC modulus by 30%-50%. In addition, and unexpectedly, we discovered that tidemark patterning was severely disrupted, as was hedgehog signaling, and exhibited specificity based on regional load-bearing functions of AC. Interestingly, Prg4 expression was markedly increased in highly loaded sites in mutants. Together, our data provide evidence that primary cilia orchestrate postnatal AC morphogenesis including tidemark topography, zonal matrix composition, and ambulation load responses. © 2022 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Danielle Rux
- Translational Research Program in Pediatric Orthopaedics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Kimberly Helbig
- Translational Research Program in Pediatric Orthopaedics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Biao Han
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Courtney Cortese
- Translational Research Program in Pediatric Orthopaedics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Eiki Koyama
- Translational Research Program in Pediatric Orthopaedics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Lin Han
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Maurizio Pacifici
- Translational Research Program in Pediatric Orthopaedics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
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Bailey KN, Alliston T. At the Crux of Joint Crosstalk: TGFβ Signaling in the Synovial Joint. Curr Rheumatol Rep 2022; 24:184-197. [PMID: 35499698 PMCID: PMC9184360 DOI: 10.1007/s11926-022-01074-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2022] [Indexed: 11/24/2022]
Abstract
PURPOSE OF REVIEW The effect of the transforming growth factor beta (TGFβ) signaling pathway on joint homeostasis is tissue-specific, non-linear, and context-dependent, representing a unique complexity in targeting TGFβ signaling in joint disease. Here we discuss the variety of mechanisms that TGFβ signaling employs in the synovial joint to maintain healthy joint crosstalk and the ways in which aberrant TGFβ signaling can result in joint degeneration. RECENT FINDINGS Osteoarthritis (OA) epitomizes a condition of disordered joint crosstalk in which multiple joint tissues degenerate leading to overall joint deterioration. Synovial joint tissues, such as subchondral bone, articular cartilage, and synovium, as well as mesenchymal stem cells, each demonstrate aberrant TGFβ signaling during joint disease, whether by excessive or suppressed signaling, imbalance of canonical and non-canonical signaling, a perturbed mechanical microenvironment, or a distorted response to TGFβ signaling during aging. The synovial joint relies upon a sophisticated alliance among each joint tissue to maintain joint homeostasis. The TGFβ signaling pathway is a key regulator of the health of individual joint tissues, and the subsequent interaction among these different joint tissues, also known as joint crosstalk. Dissecting the sophisticated function of TGFβ signaling in the synovial joint is key to therapeutically interrogating the pathway to optimize overall joint health.
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Affiliation(s)
- Karsyn N Bailey
- Department of Orthopaedic Surgery, University of California San Francisco, 513 Parnassus Avenue, CA, 94143, San Francisco, USA
- UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA, USA
| | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California San Francisco, 513 Parnassus Avenue, CA, 94143, San Francisco, USA.
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Thielen NGM, Neefjes M, Vitters EL, van Beuningen HM, Blom AB, Koenders MI, van Lent PLEM, van de Loo FAJ, Blaney Davidson EN, van Caam APM, van der Kraan PM. Identification of Transcription Factors Responsible for a Transforming Growth Factor-β-Driven Hypertrophy-like Phenotype in Human Osteoarthritic Chondrocytes. Cells 2022; 11:cells11071232. [PMID: 35406794 PMCID: PMC8998018 DOI: 10.3390/cells11071232] [Citation(s) in RCA: 8] [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: 02/25/2022] [Revised: 03/28/2022] [Accepted: 03/31/2022] [Indexed: 12/18/2022] Open
Abstract
During osteoarthritis (OA), hypertrophy-like chondrocytes contribute to the disease process. TGF-β's signaling pathways can contribute to a hypertrophy(-like) phenotype in chondrocytes, especially at high doses of TGF-β. In this study, we examine which transcription factors (TFs) are activated and involved in TGF-β-dependent induction of a hypertrophy-like phenotype in human OA chondrocytes. We found that TGF-β, at levels found in synovial fluid in OA patients, induces hypertrophic differentiation, as characterized by increased expression of RUNX2, COL10A1, COL1A1, VEGFA and IHH. Using luciferase-based TF activity assays, we observed that the expression of these hypertrophy genes positively correlated to SMAD3:4, STAT3 and AP1 activity. Blocking these TFs using specific inhibitors for ALK-5-induced SMAD signaling (5 µM SB-505124), JAK-STAT signaling (1 µM Tofacitinib) and JNK signaling (10 µM SP-600125) led to the striking observation that only SB-505124 repressed the expression of hypertrophy factors in TGF-β-stimulated chondrocytes. Therefore, we conclude that ALK5 kinase activity is essential for TGF-β-induced expression of crucial hypertrophy factors in chondrocytes.
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Russell BE, Rigueur D, Weaver KN, Sund K, Basil JS, Hufnagel RB, Prows CA, Oestreich A, Al-Gazali L, Hopkin RJ, Saal HM, Lyons K, Dauber A. Homozygous missense variant in BMPR1A resulting in BMPR signaling disruption and syndromic features. Mol Genet Genomic Med 2019; 7:e969. [PMID: 31493347 PMCID: PMC6825850 DOI: 10.1002/mgg3.969] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 07/12/2019] [Accepted: 08/04/2019] [Indexed: 12/12/2022] Open
Abstract
Background The bone morphogenetic protein (BMP) pathway is known to play an imperative role in bone, cartilage, and cardiac tissue formation. Truncating, heterozygous variants, and deletions of one of the essential receptors in this pathway, Bone Morphogenetic Protein Receptor Type1A (BMPR1A), have been associated with autosomal dominant juvenile polyposis. Heterozygous deletions have also been associated with cardiac and minor skeletal anomalies. Populations with atrioventricular septal defects are enriched for rare missense BMPR1A variants. Methods We report on a patient with a homozygous missense variant in BMPR1A causing skeletal abnormalities, growth failure a large atrial septal defect, severe subglottic stenosis, laryngomalacia, facial dysmorphisms, and developmental delays. Results Functional analysis of this variant shows increased chondrocyte death for cells with the mutated receptor, increased phosphorylated R‐Smads1/5/8, and loss of Sox9 expression mediated by decreased phosphorylation of p38. Conclusion This homozygous missense variant in BMPR1A appears to cause a distinct clinical phenotype.
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Affiliation(s)
- Bianca E Russell
- Division of Human Genetics, Cincinnati Children's Hospital and University of Cincinnati College of Medicine Department of Pediatrics, Cincinnati, OH, USA
| | - Diana Rigueur
- Department of Molecular, Cell & Developmental Biology, UCLA, Los Angeles, CA, USA
| | - Kathryn N Weaver
- Division of Human Genetics, Cincinnati Children's Hospital and University of Cincinnati College of Medicine Department of Pediatrics, Cincinnati, OH, USA
| | - Kristen Sund
- Division of Human Genetics, Cincinnati Children's Hospital and University of Cincinnati College of Medicine Department of Pediatrics, Cincinnati, OH, USA
| | - Janet S Basil
- Division of Human Genetics, Cincinnati Children's Hospital and University of Cincinnati College of Medicine Department of Pediatrics, Cincinnati, OH, USA
| | - Robert B Hufnagel
- Division of Human Genetics, Cincinnati Children's Hospital and University of Cincinnati College of Medicine Department of Pediatrics, Cincinnati, OH, USA
| | - Cynthia A Prows
- Division of Human Genetics, Cincinnati Children's Hospital and University of Cincinnati College of Medicine Department of Pediatrics, Cincinnati, OH, USA
| | - Alan Oestreich
- Department of Radiology, Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Lihadh Al-Gazali
- Department of Pediatrics, United Arab Emirates University, Abu Dhabi, United Arab Emirates
| | - Robert J Hopkin
- Division of Human Genetics, Cincinnati Children's Hospital and University of Cincinnati College of Medicine Department of Pediatrics, Cincinnati, OH, USA
| | - Howard M Saal
- Division of Human Genetics, Cincinnati Children's Hospital and University of Cincinnati College of Medicine Department of Pediatrics, Cincinnati, OH, USA
| | - Karen Lyons
- Department of Molecular, Cell & Developmental Biology, UCLA, Los Angeles, CA, USA.,Department of Orthopaedic Surgery, UCLA, Los Angeles, CA, USA
| | - Andrew Dauber
- Division of Endocrinology, Cincinnati Children's Hospital and University of Cincinnati College of Medicine, Department of Pediatrics, Cincinnati, OH, USA
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Thielen NGM, van der Kraan PM, van Caam APM. TGFβ/BMP Signaling Pathway in Cartilage Homeostasis. Cells 2019; 8:cells8090969. [PMID: 31450621 PMCID: PMC6769927 DOI: 10.3390/cells8090969] [Citation(s) in RCA: 130] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/09/2019] [Accepted: 08/19/2019] [Indexed: 01/15/2023] Open
Abstract
Cartilage homeostasis is governed by articular chondrocytes via their ability to modulate extracellular matrix production and degradation. In turn, chondrocyte activity is regulated by growth factors such as those of the transforming growth factor β (TGFβ) family. Members of this family include the TGFβs, bone morphogenetic proteins (BMPs), and growth and differentiation factors (GDFs). Signaling by this protein family uniquely activates SMAD-dependent signaling and transcription but also activates SMAD-independent signaling via MAPKs such as ERK and TAK1. This review will address the pivotal role of the TGFβ family in cartilage biology by listing several TGFβ family members and describing their signaling and importance for cartilage maintenance. In addition, it is discussed how (pathological) processes such as aging, mechanical stress, and inflammation contribute to altered TGFβ family signaling, leading to disturbed cartilage metabolism and disease.
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Affiliation(s)
- Nathalie G M Thielen
- Experimental Rheumatology, Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands
| | - Peter M van der Kraan
- Experimental Rheumatology, Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands
| | - Arjan P M van Caam
- Experimental Rheumatology, Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands.
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SMAD3 and SMAD4 have a more dominant role than SMAD2 in TGFβ-induced chondrogenic differentiation of bone marrow-derived mesenchymal stem cells. Sci Rep 2017; 7:43164. [PMID: 28240243 PMCID: PMC5327413 DOI: 10.1038/srep43164] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/19/2017] [Indexed: 12/22/2022] Open
Abstract
To improve cartilage formation by bone marrow-derived mesenchymal stem cells (BMSCs), the signaling mechanism governing chondrogenic differentiation requires better understanding. We previously showed that the transforming growth factor-β (TGFβ) receptor ALK5 is crucial for chondrogenesis induced by TGFβ. ALK5 phosphorylates SMAD2 and SMAD3 proteins, which then form complexes with SMAD4 to regulate gene transcription. By modulating the expression of SMAD2, SMAD3 and SMAD4 in human BMSCs, we investigated their role in TGFβ-induced chondrogenesis. Activation of TGFβ signaling, represented by SMAD2 phosphorylation, was decreased by SMAD2 knockdown and highly increased by SMAD2 overexpression. Moreover, TGFβ signaling via the alternative SMAD1/5/9 pathway was strongly decreased by SMAD4 knockdown. TGFβ-induced chondrogenesis of human BMSCs was strongly inhibited by SMAD4 knockdown and only mildly inhibited by SMAD2 knockdown. Remarkably, both knockdown and overexpression of SMAD3 blocked chondrogenic differentiation. Chondrogenesis appears to rely on a delicate balance in the amount of SMAD3 and SMAD4 as it was not enhanced by SMAD4 overexpression and was inhibited by SMAD3 overexpression. Furthermore, this study reveals that TGFβ-activated phosphorylation of SMAD2 and SMAD1/5/9 depends on the abundance of SMAD4. Overall, our findings suggest a more dominant role for SMAD3 and SMAD4 than SMAD2 in TGFβ-induced chondrogenesis of human BMSCs.
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Lee HW, Jie HB, Bollyky PL, Sarracino D, Kim TS, Wilson BS. Role of dendritic cell maturation factors produced by human invariant NKT cells in immune tolerance. J Leukoc Biol 2016; 101:989-1003. [PMID: 27837018 DOI: 10.1189/jlb.1a0416-164rrr] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Revised: 10/04/2016] [Accepted: 10/27/2016] [Indexed: 01/12/2023] Open
Abstract
In this study, we used the culture supernatant of iNKT cells to identify human myeloid DC maturation factors produced by human CD4+ iNKT cells. S100A8 had a strong maturation effect. Notably, the recombinant S100A8 protein displayed properties of DC maturation functioning, and the induction of DC differentiation by both the purified and the recombinant protein were blocked by anti-S100A8 and anti-TLR-4 mAbs. DC differentiation induced by anti-major histocompatibility complex class II/CD1d Ab, S100A8, or both was qualitatively indistinguishable from that induced by the coculture of DCs and iNKT cells or via culture supplementation with supernatants from activated CD4+ iNKT cells. S100A8 also induced CD4+/CD25+/Foxp3+ Treg cells from naïve T cells. S100A8 may contribute to DC differentiation by elevating transcription factors or activating transcription factor-2, heat shock factor-1, or both, in mature DCs. S100A8 is a novel candidate iNKT cell-dependent DC maturation factor.
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Affiliation(s)
- Hyeong-Woo Lee
- Departments of Tropical Medicine and Parasitology, Inha University School of Medicine, Incheon, Republic of Korea.,Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, Florida
| | - Hyun Bae Jie
- OncoMed Pharmaceuticals, Inc., Redwood City, California
| | - Paul L Bollyky
- Division of Infectious Diseases, Stanford University Medical Center, Stanford, California; and
| | - David Sarracino
- Thermo Fisher Scientific Biomarkers Research Initiatives in Mass Spectrometry (BRIMS) Center, Cambridge, Massachusetts
| | - Tong-Soo Kim
- Departments of Tropical Medicine and Parasitology, Inha University School of Medicine, Incheon, Republic of Korea;
| | - Brian S Wilson
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, Florida;
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9
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Focus on the p38 MAPK signaling pathway in bone development and maintenance. BONEKEY REPORTS 2015; 4:711. [PMID: 26131361 DOI: 10.1038/bonekey.2015.80] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 04/24/2015] [Indexed: 01/18/2023]
Abstract
The p38 mitogen-activated protein kinase (MAPK) signaling pathway can be activated in response to a wide range of extracellular signals. As a consequence, it can generate many different biological effects that depend on the stimulus and on the activated cell type. Therefore, this pathway has been found to regulate many aspects of tissue development and homeostasis. Recent work with the aid of genetically modified mice has highlighted the physiological functions of this pathway in skeletogenesis and postnatal bone maintenance. In this review, emphasis is given to the roles of the p38 MAPK pathway in chondrocyte, osteoblast and osteoclast biology. In particular, we describe the molecular mechanisms of p38 MAPK activation and downstream targets. The requirement of this pathway in physiological bone development and homeostasis is demonstrated by the ability of p38 MAPK to regulate master transcription factors controlling geneses and functions of chondrocytes, osteoblasts and osteoclasts.
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Kim KO, Sampson ER, Maynard RD, O'Keefe RJ, Chen D, Drissi H, Rosier RN, Hilton MJ, Zuscik MJ. Ski inhibits TGF-β/phospho-Smad3 signaling and accelerates hypertrophic differentiation in chondrocytes. J Cell Biochem 2012; 113:2156-66. [PMID: 22461172 DOI: 10.1002/jcb.24089] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Since transforming growing factor-β (TGF-β)/Smad signaling inhibits chondrocyte maturation, endogenous negative regulators of TGF-β signaling are likely also important regulators of the chondrocyte differentiation process. One such negative regulator, Ski, is an oncoprotein that is known to inhibit TGF-β/Smad3 signaling via its interaction with phospho-Smad3 and recruitment of histone deacetylases (HDACs) to the DNA binding complex. Based on this, we hypothesized that Ski inhibits TGF-β signaling and accelerates maturation in chondrocytes via recruitment of HDACs to transcriptional complexes containing Smads. We tested this hypothesis in chick upper sternal chondrocytes (USCs), where gain and loss of Ski expression experiments were performed. Over-expression of Ski not only reversed the inhibitory effect of TGF-β on the expression of hypertrophic marker genes such as type X collagen (colX) and osteocalcin, it induced these genes basally as well. Conversely, knockdown of Ski by RNA interference led to a reduction of colX and osteocalcin expression under basal conditions. Furthermore, Ski blocked TGF-β induction of cyclinD1 and caused a basal up-regulation of Runx2, consistent with the observed acceleration of hypertrophy. Regarding mechanism, not only does Ski associate with phospho-Smad2 and 3, but its association with phospho-Smad3 is required for recruitment of HDAC4 and 5. Implicating this recruitment of HDACs in the phenotypic effects of Ski in chondrocytes, the HDAC inhibitor SAHA reversed the up-regulation of colX and osteocalcin in Ski over-expressing cells. These results suggest that inhibition of TGF-β signaling by Ski, which involves its association with phospho-Smad3 and recruitment of HDAC4 and 5, leads to accelerated chondrocyte differentiation.
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Affiliation(s)
- Kyung-Ok Kim
- Department of Orthopaedics and Rehabilitation, Center for Musculoskeletal Research, University of Rochester Medical Center, 601 Elmwood Avenue Box 665, Rochester, New York 14642, USA
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Zhu X, Wang J, Xie G, Feng H, Li X, Liu L, Wang X, Li D, Liu Z, Qian J, Wang Z, Liu G. Effect of copper on the expression of TGF-β in incubated chondrocytes of newborn pigs. Biol Trace Elem Res 2011; 143:1461-9. [PMID: 21267671 DOI: 10.1007/s12011-011-8966-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Accepted: 01/11/2011] [Indexed: 12/24/2022]
Abstract
This experiment was conducted to measure the effect of copper supplementation on TGF-β gene expression in chondrocytes of newborn pigs. Chondrocytes were cultured in media containing 15% fetal calf serum supplemented with 0, 15.6, 31.2, and 62.5 μmol/L copper in 90-mm culture plate. Total RNA was isolated from chondrocytes, and TGF-β cDNA was synthesized, amplified, and sequenced. The expression level of TGF-β was examined by reverse transcription polymerase chain reaction. The results showed that the sequence of the cloned TGF-β gene was 99.4% identical to that in GenBank. The expression of TGF-β increased in culture media added with final concentration of 15.6, 31.2, and 62.5 μmol/L copper. In this study, the optimal copper concentration and optimal culture time for the highest level of TGF-β expression were 31.2 μmol/L and 48 h, respectively.
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Affiliation(s)
- Xiaoyan Zhu
- College of Animal Science and Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun, 130062, China
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12
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Susperregui ARG, Gamell C, Rodríguez-Carballo E, Ortuño MJ, Bartrons R, Rosa JL, Ventura F. Noncanonical BMP signaling regulates cyclooxygenase-2 transcription. Mol Endocrinol 2011; 25:1006-17. [PMID: 21436263 DOI: 10.1210/me.2010-0515] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Activation of p38 MAPK has been shown to be relevant for a number of bone morphogenetic protein (BMP) physiological effects. We report here the involvement of noncanonical phosphorylated mothers against decapentaplegic (Smad) signaling in the transcriptional induction of Cox2 (Ptgs2) by BMP-2 in mesenchymal cells and organotypic calvarial cultures. We demonstrate that different regulatory elements are required for regulation of Cox2 expression by BMP-2: Runt-related transcription factor-2 and cAMP response element sites are essential, whereas a GC-rich Smad binding element is important for full responsiveness. Efficient transcriptional activation requires cooperation between transcription factors because mutation of any element results in a strong decrease of BMP-2 responsiveness. BMP-2 activation of p38 leads to increased recruitment of activating transcription factor-2, Runx2, Smad, and coactivators such as p300 at the responsive sites in the Cox2 proximal promoter. We demonstrate, by either pharmacological or genetic analysis, that maximal BMP-2 effects on Cox2 and JunB expression require the function of p38 and its downstream effector mitogen/stress-activated kinase 1. Altogether our results strongly suggest that cooperative effects between canonical and noncanonical BMP signaling allow the fine-tuning of BMP transcriptional responses on specific target genes.
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Affiliation(s)
- Antonio R G Susperregui
- Departament de Ciències Fisiològiques II, Bellvitge Biomedical Research Institute, C/ Feixa Llarga s/n., L'Hospitalet de Llobregat, Universitat de Barcelona, E-08907 Barcelona, Spain
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13
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Sullivan BP, Kassel KM, Manley S, Baker AK, Luyendyk JP. Regulation of transforming growth factor-β1-dependent integrin β6 expression by p38 mitogen-activated protein kinase in bile duct epithelial cells. J Pharmacol Exp Ther 2011; 337:471-8. [PMID: 21303922 DOI: 10.1124/jpet.110.177337] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Bile duct epithelial cells (BDECs) contribute to liver fibrosis by expressing αVβ6 integrin, a critical activator of latent transforming growth factor β (TGF-β). β6 integrin (Itgβ6) mRNA induction and αVβ6 integrin expression in BDECs are partially TGF-β-dependent. However, the signaling pathways required for TGF-β-dependent Itgβ6 mRNA induction in BDECs are not known. We tested the hypothesis that the p38 mitogen-activated protein kinase (MAPK) signaling pathway contributes to TGF-β1 induction of Itgβ6 mRNA by activating SMAD and activator protein 1 (AP-1) transcription factors. Pretreatment of transformed human BDECs (MMNK-1 cells) with two different p38 MAPK inhibitors, but not a control compound, inhibited TGF-β1 induction of Itgβ6 mRNA. Inhibition of p38 also reduced TGF-β1 activation of a SMAD-dependent reporter construct. Expression of a dominant-negative SMAD3 (SMAD3ΔC) significantly reduced TGF-β1-induced Itgβ6 mRNA expression. Expression of JunB mRNA, but not other AP-1 proteins, increased in TGF-β1-treated MMNK-1 cells, and induction of JunB expression was p38-dependent. Consistent with a requirement for de novo induction of JunB protein, cycloheximide pretreatment inhibited TGF-β1 induction of Itgβ6 mRNA. Expression of a dominant-negative AP-1 mutant (TAM67) also inhibited TGF-β1 induction of Itgβ6 mRNA. Overall, the results suggest that p38 contributes to TGF-β1-induced Itgβ6 mRNA expression in MMNK-1 cells by regulating activation of both SMAD and AP-1 transcription factors.
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Affiliation(s)
- Bradley P Sullivan
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, MS-1018, Kansas City, KS 66160, USA
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Li TF, Gao L, Sheu TJ, Sampson ER, Flick LM, Konttinen YT, Chen D, Schwarz EM, Zuscik MJ, Jonason JH, O'Keefe RJ. Aberrant hypertrophy in Smad3-deficient murine chondrocytes is rescued by restoring transforming growth factor beta-activated kinase 1/activating transcription factor 2 signaling: a potential clinical implication for osteoarthritis. ACTA ACUST UNITED AC 2010; 62:2359-69. [PMID: 20506210 DOI: 10.1002/art.27537] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVE To investigate the biologic significance of Smad3 in the progression of osteoarthritis (OA), the crosstalk between Smad3 and activating transcription factor 2 (ATF-2) in the transforming growth factor beta (TGFbeta) signaling pathway, and the effects of ATF-2 overexpression and p38 activation in chondrocyte differentiation. METHODS Joint disease in Smad3-knockout (Smad3(-/-)) mice was examined by microfocal computed tomography and histologic analysis. Numerous in vitro methods including immunostaining, real-time polymerase chain reaction, Western blotting, an ATF-2 DNA-binding assay, and a p38 kinase activity assay were used to study the various signaling responses and protein interactions underlying the altered chondrocyte phenotype in Smad3(-/-) mice. RESULTS In Smad3(-/-) mice, an end-stage OA phenotype gradually developed. TGFbeta-activated kinase 1 (TAK1)/ATF-2 signaling was disrupted in Smad3(-/-) mouse chondrocytes at the level of p38 MAP kinase (MAPK) activation, resulting in reduced ATF-2 phosphorylation and transcriptional activity. Reintroduction of Smad3 into Smad3(-/-) cells restored the normal p38 response to TGFbeta. Phosphorylated p38 formed a complex with Smad3 by binding to a portion of Smad3 containing both the MAD homology 1 and linker domains. Additionally, Smad3 inhibited the dephosphorylation of p38 by MAPK phosphatase 1 (MKP-1). Both ATF-2 overexpression and p38 activation repressed type X collagen expression in wild-type and Smad3(-/-) chondrocytes. P38 was detected in articular cartilage and perichondrium; articular and sternal chondrocytes expressed p38 isoforms alpha, beta, and gamma, but not delta. CONCLUSION Smad3 is involved in both the onset and progression of OA. Loss of Smad3 abrogates TAK1/ATF-2 signaling, most likely by disrupting the Smad3-phosphorylated p38 complex, thereby promoting p38 dephosphorylation and inactivation by MKP-1. ATF-2 and p38 activation inhibit chondrocyte hypertrophy. Modulation of p38 isoform activity may provide a new therapeutic approach for OA.
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Affiliation(s)
- Tian-Fang Li
- University of Rochester, Rochester, New York 14642, USA
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15
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Zhang M, Wang M, Tan X, Li TF, Zhang YE, Chen D. Smad3 prevents beta-catenin degradation and facilitates beta-catenin nuclear translocation in chondrocytes. J Biol Chem 2010; 285:8703-10. [PMID: 20097766 DOI: 10.1074/jbc.m109.093526] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Our previous study demonstrated that transforming growth factor (TGF)-beta activates beta-catenin signaling through Smad3 interaction with beta-catenin in chondrocytes. In the present studies, we further investigated the detailed molecular mechanism of the cross-talk between TGF-beta/Smad3 and Wnt/beta-catenin signaling pathways. We found that C-terminal Smad3 interacted with both the N-terminal region and the middle region of beta-catenin protein in a TGF-beta-dependent manner. Both Smad3 and Smad4 were required for the interaction with beta-catenin and protected beta-catenin from an ubiquitin-proteasome-dependent degradation. In addition, the formation of the Smad3-Smad4-beta-catenin protein complex also mediated beta-catenin nuclear translocation. This Smad3-mediated regulatory mechanism of beta-catenin protein stability enhanced the activity of beta-catenin to activate downstream target genes during chondrogenesis. Our findings demonstrate a novel mechanism between TGF-beta and Wnt/beta-catenin signaling pathways during chondrocyte development.
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Affiliation(s)
- Ming Zhang
- Department of Orthopaedics and Rehabilitation, Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, New York 14642, USA
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16
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Yanagino T, Yuasa K, Nagahama M, Matsuda Y, Tsuji A. Transcriptional regulation of fibrillin-2 gene by E2F family members in chondrocyte differentiation. J Cell Biochem 2009; 106:580-8. [DOI: 10.1002/jcb.22029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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17
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Deng X, Liu H, Huang J, Cheng L, Keller ET, Parsons SJ, Hu CD. Ionizing radiation induces prostate cancer neuroendocrine differentiation through interplay of CREB and ATF2: implications for disease progression. Cancer Res 2009; 68:9663-70. [PMID: 19047143 DOI: 10.1158/0008-5472.can-08-2229] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Radiation therapy is a first-line treatment for prostate cancer patients with localized tumors. Although some patients respond well to the treatment, approximately 10% of low-risk and up to 60% of high-risk prostate cancer patients experience recurrent tumors. However, the molecular mechanisms underlying tumor recurrence remain largely unknown. Here we show that fractionated ionizing radiation (IR) induces differentiation of LNCaP prostate cancer cells into neuroendocrine (NE)-like cells, which are known to be implicated in prostate cancer progression, androgen-independent growth, and poor prognosis. Further analyses revealed that two cyclic AMP-responsive element binding transcription factors, cyclic AMP-response element binding protein (CREB) and activating transcription factor 2 (ATF2), function as a transcriptional activator and a repressor, respectively, of NE-like differentiation and that IR induces NE-like differentiation by increasing the nuclear content of phospho-CREB and cytoplasmic accumulation of ATF2. Consistent with this notion, stable expression of a nonphosphorylatable CREB or a constitutively nuclear-localized ATF2 in LNCaP cells inhibits IR-induced NE-like differentiation. IR-induced NE-like morphologies are reversible, and three IR-resistant clones isolated from dedifferentiated cells have acquired the ability to proliferate and lost the NE-like cell properties. In addition, these three IR-resistant clones exhibit differential responses to IR- and androgen depletion-induced NE-like differentiation. However, they are all resistant to cell death induced by IR and the chemotherapeutic agent docetaxel and to androgen depletion-induced growth inhibition. These results suggest that radiation therapy-induced NE-like differentiation may represent a novel pathway by which prostate cancer cells survive the treatment and contribute to tumor recurrence.
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Affiliation(s)
- Xuehong Deng
- Department of Medicinal Chemistry and Molecular Pharmacology and the Purdue Cancer Center, Purdue University, West Lafayette, Indiana 47907, USA
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Solomon LA, Bérubé NG, Beier F. Transcriptional regulators of chondrocyte hypertrophy. ACTA ACUST UNITED AC 2008; 84:123-30. [DOI: 10.1002/bdrc.20124] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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19
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Kim ES, Moon A. Role of Transforming Growth Factor-β in Tumor Invasion and Metastasis. Toxicol Res 2007. [DOI: 10.5487/tr.2007.23.3.197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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20
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Dong YF, Soung DY, Chang Y, Enomoto-Iwamoto M, Paris M, O'Keefe RJ, Schwarz EM, Drissi H. Transforming growth factor-beta and Wnt signals regulate chondrocyte differentiation through Twist1 in a stage-specific manner. Mol Endocrinol 2007; 21:2805-20. [PMID: 17684115 DOI: 10.1210/me.2007-0199] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We investigated the molecular mechanisms underlying the transition between immature and mature chondrocytes downstream of TGF-beta and canonical Wnt signals. We used two developmentally distinct chondrocyte models isolated from the caudal portion of embryonic chick sternum or chick growth plates. Lower sternal chondrocytes exhibited immature phenotypic features, whereas growth plate-extracted cells displayed a hypertrophic phenotype. TGF-beta significantly induced beta-catenin in immature chondrocytes, whereas it repressed it in mature chondrocytes. TGF-beta further enhanced canonical Wnt-mediated transactivation of the Topflash reporter expression in lower sternal chondrocytes. However, it inhibited Topflash activity in a time-dependent manner in growth plate chondrocytes. Our immunoprecipitation experiments showed that TGF-beta induced Sma- and Mad-related protein 3 interaction with T-cell factor 4 in immature chondrocytes, whereas it inhibited this interaction in mature chondrocytes. Similar results were observed by chromatin immunoprecipitation showing that TGF-beta differentially shifts T-cell factor 4 occupancy on the Runx2 promoter in lower sternal chondrocytes vs. growth plate chondrocytes. To further determine the molecular switch between immature and hypertrophic chondrocytes, we assessed the expression and regulation of Twist1 and Runx2 in both cell models upon treatment with TGF-beta and Wnt3a. We show that Runx2 and Twist1 are differentially regulated during chondrocyte maturation. Furthermore, whereas TGF-beta induced Twist1 in mature chondrocytes, it inhibited Runx2 expression in these cells. Opposite effects were observed upon Wnt3a treatment, which predominates over TGF-beta effects on these cells. Finally, overexpression of chick Twist1 in mature chondrocytes dramatically inhibited their hypertrophy. Together, our findings show that Twist1 may be an important regulator of chondrocyte progression toward terminal maturation in response to TGF-beta and canonical Wnt signaling.
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Affiliation(s)
- Yu-Feng Dong
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, New York 14642, USA
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21
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Kim ES, Sohn YW, Moon A. TGF-beta-induced transcriptional activation of MMP-2 is mediated by activating transcription factor (ATF)2 in human breast epithelial cells. Cancer Lett 2007; 252:147-56. [PMID: 17258390 DOI: 10.1016/j.canlet.2006.12.016] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Revised: 12/14/2006] [Accepted: 12/14/2006] [Indexed: 11/16/2022]
Abstract
We have previously shown that transforming growth factor (TGF)-beta up-regulates matrix metalloproteinase (MMP)-2 leading to the induction of oncogenic signaling in preneoplastic MCF10A human breast epithelial cells. The present study investigated the mechanism of transcriptional regulation of MMP-2 by TGF-beta in MCF10A cells. By using 5' deletion constructs of MMP-2 promoter, we demonstrated that binding sites for p53, S1, AP-1 and Sp1, and to a lesser extent CREB, GCN-His and PEA3, were potential cis-acting elements for TGF-beta-induced transcriptional activation of MMP-2 in MCF10A cells. Since activating transcription factor (ATF)2 was shown to mediate the TGF-beta-induced cellular responses, we examined the involvement of ATF2 in TGF-beta-activated MMP-2 gene transcription. TGF-beta increased DNA binding activity of AP-1 in which ATF2 was involved as evidenced by electrophoretic mobility shift assay. TGF-beta induced phosphorylation of ATF2 through p38 MAPK signaling. A dominant-negative (DN) ATF2 significantly inhibited the TGF-beta-induced up-regulation of MMP-2, but not that of MMP-9, suggesting that ATF2 may be a transcription factor responsible for transcriptional activation of MMP-2 gene by TGF-beta. Invasive and migratory phenotypes induced by TGF-beta were significantly inhibited by DN ATF2, indicating a critical role of ATF2 in TGF-beta-induced oncogenic progression of MCF10A cells. Taken together, this study demonstrates that ATF2 mediates the TGF-beta-induced MMP-2 transcriptional activation, elucidating a molecular mechanism for the malignant progression of human breast epithelial cells exerted by TGF-beta.
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Affiliation(s)
- Eun-Sook Kim
- College of Pharmacy, Duksung Women's University, Seoul 132-714, Republic of Korea
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22
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Liu G, Ding W, Neiman J, Mulder KM. Requirement of Smad3 and CREB-1 in mediating transforming growth factor-beta (TGF beta) induction of TGF beta 3 secretion. J Biol Chem 2006; 281:29479-90. [PMID: 16891311 DOI: 10.1074/jbc.m600579200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Because increased transforming growth factor-beta (TGFbeta) production by tumor cells contributes to cancer progression through paracrine mechanisms, identification of critical points that can be targeted to block TGFbeta production is important. Previous studies have identified the precise signaling components and promoter elements required for TGFbeta induction of TGFbeta1 expression in epithelial cells (Yue, J., and Mulder, K. M. (2000) J. Biol. Chem. 275, 30765-30773). To determine how regulation of TGFbeta3 expression differs from that of TGFbeta1, we identified the precise signaling pathways and transcription factor-binding sites that are required for TGFbeta3 gene expression. By using mutational analysis in electrophoresis mobility shift assays (EMSAs), we demonstrated that the c-AMP-responsive element (CRE) site in the TGFbeta3 promoter was required for TGFbeta-inducible TGFbeta3 expression. Electrophoresis mobility supershift assays indicated that CRE-binding protein 1 (CREB1) and Smad3 were the major components present in this TGFbeta-inducible complex. Furthermore, by using chromatin immunoprecipitation assays, we demonstrated that CREB-1, ATF-2, and c-Jun bound constitutively at the TGFbeta3 promoter (-100 to +1), whereas Smad3 bound at this site only after TGFbeta stimulation. In addition, inhibition of JNK and p38 suppressed TGFbeta induction of TGFbeta3 transactivation, whereas inhibition of ERK and protein kinase A had no effect. Small interfering RNA-CREB1 and small interfering RNA-Smad3 significantly inhibited TGFbeta stimulation of TGFbeta3 promoter reporter activity and TGFbeta3 production. Our results indicate that TGFbeta activation of the TGFbeta3 promoter CRE site, which leads to TGFbeta3 production, is required for TGFbetaRII, JNK, p38, and Smad3 but was independent of protein kinase A, ERK, and Smad4.
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Affiliation(s)
- Guangming Liu
- Department of Pharmacology, Penn State College of Medicine, Hershey, Pennsylvania 17033, USA
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Nakaoka R, Hsiong SX, Mooney DJ. Regulation of chondrocyte differentiation level via co-culture with osteoblasts. TISSUE ENGINEERING 2006; 12:2425-33. [PMID: 16995776 DOI: 10.1089/ten.2006.12.2425] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The close apposition of osteoblasts and chondrocytes in bone and their interaction during bone development and regeneration suggest that they may each regulate the other's growth and differentiation. In these studies, osteoblasts and chondrocytes were co-cultured in vitro, with both direct and indirect contact. Proliferation of the co-cultured chondrocytes was enhanced using soluble factors produced from the osteoblasts, and the differentiation level of the osteoblasts influenced the differentiation level of the chondrocytes. In addition, the chondrocytes regulated differentiation of the co-cultured osteoblasts using soluble factors and direct contact. These data support the possibility of direct, reciprocal instructive interactions between chondrocytes and osteoblasts in a variety of normal processes and further suggest that it may be necessary to account for this signaling in the regeneration of complex tissues comprising cartilage and mineralized tissue.
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Affiliation(s)
- Ryusuke Nakaoka
- Division of Medical Devices, National Institute of Health Sciences, Tokyo, Japan.
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Li TF, Chen D, Wu Q, Chen M, Sheu TJ, Schwarz EM, Drissi H, Zuscik M, O'Keefe RJ. Transforming growth factor-beta stimulates cyclin D1 expression through activation of beta-catenin signaling in chondrocytes. J Biol Chem 2006; 281:21296-21304. [PMID: 16690606 PMCID: PMC2649822 DOI: 10.1074/jbc.m600514200] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transforming growth factor-beta (TGF-beta) plays an essential role in chondrocyte maturation. It stimulates chondrocyte proliferation but inhibits chondrocyte differentiation. In this study, we found that TGF-beta rapidly induced beta-catenin protein levels and signaling in murine neonatal sternal primary chondrocytes. TGF-beta-increased beta-catenin induction was reproduced by overexpression of SMAD3 and was absent in Smad3(-/-) chondrocytes treated with TGF-beta. SMAD3 inhibited beta-transducin repeat-containing protein-mediated degradation of beta-catenin and immunoprecipitated with beta-catenin following TGF-beta treatment. Both SMAD3 and beta-catenin co-localized to the nucleus after TGF-beta treatment. Although both TGF-beta and beta-catenin stimulated cyclin D(1) expression in chondrocytes, the effect of TGF-beta was inhibited with beta-catenin gene deletion or SMAD3 loss of function. These results demonstrate that TGF-beta stimulates cyclin D(1) expression at least in part through activation of beta-catenin signaling.
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Affiliation(s)
- Tian-Fang Li
- Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester, Rochester, New York 14642
| | - Di Chen
- Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester, Rochester, New York 14642
| | - Qiuqian Wu
- Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester, Rochester, New York 14642
| | - Mo Chen
- Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester, Rochester, New York 14642
| | - Tzong-Jen Sheu
- Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester, Rochester, New York 14642
| | - Edward M Schwarz
- Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester, Rochester, New York 14642
| | - Hicham Drissi
- Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester, Rochester, New York 14642
| | - Michael Zuscik
- Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester, Rochester, New York 14642
| | - Regis J O'Keefe
- Department of Orthopaedics, Center for Musculoskeletal Research, University of Rochester, Rochester, New York 14642.
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Li TF, Darowish M, Zuscik MJ, Chen D, Schwarz EM, Rosier RN, Drissi H, O'Keefe RJ. Smad3-deficient chondrocytes have enhanced BMP signaling and accelerated differentiation. J Bone Miner Res 2006; 21:4-16. [PMID: 16355269 PMCID: PMC2649698 DOI: 10.1359/jbmr.050911] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Revised: 07/30/2005] [Accepted: 09/16/2005] [Indexed: 02/06/2023]
Abstract
UNLABELLED Smad3 deficiency accelerates chondrocyte maturation and leads to osteoarthritis. Primary chondrocytes without Smad3 lack compensatory increases of TGF-beta signaling factors, but BMP-related gene expression is increased. Smad2 or Smad3 overexpression and BMP blockade abrogate accelerated maturation in Smad3-/- chondrocytes. BMP signaling is increased in TGF-beta deficiency and is required for accelerated chondrocyte maturation. INTRODUCTION Disruption of TGF-beta signaling results in accelerated chondrocyte maturation and leads to postnatal dwarfism and premature osteoarthritis. The mechanisms involved in this process were studied using in vitro murine chondrocyte cultures. MATERIALS AND METHODS Primary chondrocytes were isolated from the sterna of neonatal wildtype and Smad3-/- mice. Expressions of maturational markers, as well as genes involved in TGF-beta and BMP signaling were examined. Chondrocytes were treated with TGF-beta and BMP-2, and effects on maturation-related genes and BMP/TGF-beta responsive reporters were examined. Recombinant noggin or retroviral vectors expressing Smad2 or Smad3 were added to the cultures. RESULTS Expression of colX and other maturational markers was markedly increased in Smad3-/- chondrocytes. Smad3-/- chondrocytes lacked compensatory increases in Smad2, Smad4, TGFRII, Sno, or Smurf2 and had reduced expression of TGF-beta1 and TGFRI. In contrast, Smad1, Smad5, BMP2, and BMP6 expression was increased, suggesting a shift from TGF-beta toward BMP signaling. In Smad3-/- chondrocytes, alternative TGF-beta signaling pathways remained responsive, as shown by luciferase assays. These non-Smad3-dependent TGF-beta pathways reduced colX expression and alkaline phosphatase activity in TGF-beta-treated Smad3-/- cultures, but only partially. In contrast, Smad3-/- chondrocytes were more responsive to BMP-2 treatment and had increased colX expression, phosphoSmads 1, 5, and 8 levels, and luciferase reporter activity. Overexpression of both Smad2 and Smad3 blocked spontaneous maturation in Smad3-deficient chondrocytes. Maturation was also abrogated by the addition of noggin, an extracellular BMP inhibitor. CONCLUSIONS These findings show a key role for BMP signaling during the chondrocyte maturation, occurring with loss of TGF-beta signaling with important implications for osteoarthritis and cartilage diseases.
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Affiliation(s)
- Tian-Fang Li
- Center for Musculoskeletal Research, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
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Abstract
PURPOSE OF REVIEW The attempt of this review is to bring into focus the potential role of dietary salt intake in progression of chronic kidney disease. RECENT FINDINGS Ongoing work has elucidated a role for dietary salt intake in modulating intrarenal production of transforming growth factor-beta1. The mechanism is independent of angiotensin II and systemic blood pressure and involves activation of vascular endothelium by dietary salt intake with release of this growth factor. In this model, transforming growth factor-beta1 serves an autacoid function by stimulating nitric oxide production by the endothelium. In turn, endothelium-derived nitric oxide modulates production of this growth factor. The model further predicts that individuals who have lost the requisite endothelial cell flexibility to adapt to this environmental stress (a high salt diet) are potentially at increased risk of developing end-organ damage from excess salt intake. Animal and human studies are presented to support this working hypothesis. SUMMARY Overproduction of transforming growth factor-beta1 permits excess biological activity of this important fibrogenic growth factor with subsequent development or acceleration of vascular and kidney damage. In patients with diseases whose pathogenesis is related to excess production of transforming growth factor-beta1, such as chronic allograft nephropathy and diabetic nephropathy, increased salt intake may hasten loss of function, particularly if nitric oxide production does not increase. The role that endothelial cell plasticity plays in altering vascular tone and renal function, especially in response to changes in dietary salt intake, should be examined further in chronic kidney disease.
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Affiliation(s)
- Paul W Sanders
- Nephrology Research and Training Center, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, 642 Lyons-Harrison Research Building, 1530 Third Avenue South, Birmingham, AL 35294-0007, USA.
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Zhang R, Murakami S, Coustry F, Wang Y, de Crombrugghe B. Constitutive activation of MKK6 in chondrocytes of transgenic mice inhibits proliferation and delays endochondral bone formation. Proc Natl Acad Sci U S A 2005; 103:365-70. [PMID: 16387856 PMCID: PMC1326166 DOI: 10.1073/pnas.0507979103] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Accumulating in vitro evidence suggests that the p38 mitogen-activated protein kinase (MAPK) pathway is involved in endochondral ossification. To investigate the role of this pathway in endochondral ossification, we generated transgenic mice with expression in chondrocytes of a constitutively active mutant of MKK6, a MAPK kinase that specifically activates p38. These mice had a dwarf phenotype characterized by reduced chondrocyte proliferation, inhibition of hypertrophic chondrocyte differentiation, and a delay in the formation of primary and secondary ossification centers. Histological analysis with in situ hybridization showed reduced expression of Indian hedgehog, PTH/PTH-related peptide receptor (PTH, parathyroid hormone), cyclin D1, and increased expression of p21 in chondrocytes. In addition, both in vivo and in transfected cells, p38 signaling increased the transcriptional activity of Sox9, a transcription factor essential for chondrocyte differentiation. In agreement with this observation, transgenic mice that express a constitutively active mutant of MKK6 in chondrocytes showed phenotypes similar to those of mice that overexpress SOX9 in chondrocytes. These observations are consistent with the notion that increased activity of Sox9 accounts at least in part for the phenotype caused by constitutive activation of MKK6 in chondrocytes. Therefore, our study provides in vivo evidence for the role of p38 in endochondral ossification and suggests that Sox9 is a likely downstream target of the p38 MAPK pathway.
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Affiliation(s)
- Ren Zhang
- Department of Molecular Genetics, Graduate Program in Genes and Development, University of Texas, M. D. Anderson Cancer Center, Houston, TX 77030, USA
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Dong Y, Drissi H, Chen M, Chen D, Zuscik MJ, Schwarz EM, O’Keefe RJ. Wnt-mediated regulation of chondrocyte maturation: modulation by TGF-beta. J Cell Biochem 2005; 95:1057-68. [PMID: 15962307 PMCID: PMC2649667 DOI: 10.1002/jcb.20466] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Wnt proteins are expressed during limb morphogenesis, yet their role and mechanism of action remains unclear during long bone growth. Wnt expression, effects and modulation of signaling events by BMP and transforming growth factor-beta (TGF-beta) were evaluated in chick embryonic chondrocytes. Chondrocyte cell cultures underwent spontaneous maturation with increased expression of colX and this was associated with an increase in the expression of multiple Wnts, including Wnt 4, 5a, 8c, and 9a. Both parathyroid hormone related peptide (PTHrP) and TGF-beta inhibited colX, but had disparate effects on Wnt expression. While TGF-beta strongly inhibited all Wnts, PTHrP did not inhibit either Wnt8c or Wnt9a and had lesser effects on the expression of the other Wnts. BMP-2 induced colX expression, and also markedly increased Wnt8c expression. Overexpression of beta-catenin and/or T cell factor (TCF)-4 also induced the type X collagen promoter. Overexpression of Wnt8c induced maturation, as did overexpression of beta-catenin. The Wnt8c/beta-catenin maturational effects were enhanced by BMP-2 and inhibited by TGF-beta. TGF-beta also inhibited activation of the Topflash reporter by beta-catenin, suggesting a direct inhibitory effect since the Topflash reporter contains only beta-catenin binding sequences. In turn beta-catenin inhibited activation of the p3TP-Luc reporter by TGF-beta, although the effect was partial. Thus, Wnt/beta-catenin signaling is a critical regulator of the rate of chondrocyte differentiation. Moreover, this pathway is modulated by members of the TGF-beta family and demonstrates the highly integrated nature of signals controlling endochondral ossification.
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Affiliation(s)
| | | | | | | | | | | | - Regis J. O’Keefe
- Correspondence to: Regis J. O’Keefe, MD, PhD, Department of Orthopaedics, University of Rochester, Medical Center Rochester, NY 14642. E-mail: Regis_O’
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Drissi H, Zuscik M, Rosier R, O'Keefe R. Transcriptional regulation of chondrocyte maturation: Potential involvement of transcription factors in OA pathogenesis. Mol Aspects Med 2005; 26:169-79. [PMID: 15811433 DOI: 10.1016/j.mam.2005.01.003] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The principle function of articular cartilage is to provide a low friction load-bearing surface that facilitates free movement of joints. Maintenance of this surface depends on the maturational arrest of chondrocytes before terminal hypertrophic differentiation occurs [Exp. Cell Res. 216 (1995) 191; Osteoarthritis Cartilage 7 (1999) 389; J. Cell Biol. 139 (1997) 541; J. Cell Biol. 145 (1999) 783]. In contrast to endochondral ossification which involves a programmed process of chondrocyte maturation culminating in terminal hypertrophy and mineralization [Nat. Genet. 9 (1995) 15], articular chondrocytes (ACs) are constrained from completing the maturational program as evidenced by a lack of type X collagen (colX) and alkaline phosphatase expression [Arthritis Res. 3 (2001) 107; Biochem. J. 362 (2002) 473]. Also, ACs are not responsive to factors that impact the maturational process, including bone morphogenetic protein-2 (BMP-2), a potent stimulator of chondrocyte maturation [J. Orthop. Res. 14 (1996) 937]. Factors that constrain AC maturation are only relieved under unique circumstances such as in osteoarthritis (OA), where proliferation and an increase in the expression of hypertrophic hallmarks indicates that the cells have differentiated into a mature phenotype [Calcif. Tissue Int. 63 (2000) 230]. OA may thus involve the functional loss of mechanisms that arrest articular cartilage differentiation. Responsiveness to various growth or systemic factors translates into activation or repression of specific genes through transcriptional mediators. Understanding the downstream mechanisms involved in this process is of paramount importance. Thus, unraveling the molecular interplay between various factors that regulate chondrocyte maturation during OA occurrence and progression is the main focus of ongoing efforts.
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Affiliation(s)
- Hicham Drissi
- The Center for Musculoskeletal Research, University of Rochester, Rochester, NY 14642, United States.
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Pearson AG, Curtis MA, Waldvogel HJ, Faull RLM, Dragunow M. Activating transcription factor 2 expression in the adult human brain: Association with both neurodegeneration and neurogenesis. Neuroscience 2005; 133:437-51. [PMID: 15878807 DOI: 10.1016/j.neuroscience.2005.02.029] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2004] [Revised: 02/15/2005] [Accepted: 02/20/2005] [Indexed: 11/23/2022]
Abstract
Activating transcription factor 2 (ATF2) is a member of the activator protein-1 family of transcription factors, which includes c-Jun and c-Fos. ATF2 is highly expressed in the mammalian brain although little is known about its function in nerve cells. Knockout mouse studies show that this transcription factor plays a role in neuronal migration during development but over-expression of ATF2 in neuronal-like cell culture promotes nerve cell death. Using immunohistochemical techniques we demonstrate ATF2 expression in the normal human brain is neuronal, is found throughout the cerebral cortex and is particularly high in the granule cells of the hippocampus, in the brain stem, in the pigmented cells of the substantia nigra and locus coeruleus, and in the granule and molecular cell layers of the cerebellum. In contrast to normal cases, ATF2 expression is down-regulated in the hippocampus, substantia nigra pars compacta and caudate nucleus of the neurological diseases Alzheimer's, Parkinson's and Huntington's, respectively. Paradoxically, an increase in ATF2 expression was found in the subependymal layer of Huntington's disease cases, compared with normal brains; a region reported to contain increased numbers of proliferating progenitor cells in Huntington's disease. We propose ATF2 plays a role in neuronal viability in the normal brain, which is compromised in susceptible regions of neurological diseases leading to its down-regulation. In contrast, the increased expression of ATF2 in the subependymal layer of Huntington's disease suggests a role for ATF2 in some aspect of neurogenesis in the diseased brain.
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Affiliation(s)
- A G Pearson
- Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
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Li TF, O'Keefe RJ, Chen D. TGF-beta signaling in chondrocytes. FRONTIERS IN BIOSCIENCE : A JOURNAL AND VIRTUAL LIBRARY 2005; 10:681-8. [PMID: 15569609 PMCID: PMC2647990 DOI: 10.2741/1563] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Transforming growth factor-beta (TGF-beta) regulates a large variety of cellular activities. Binding of TGF- beta to its cell surface receptor triggers several signaling cascades, among which the TGF- beta -Smad pathway is the most extensively studied. TGF- beta also activates protein kinases, including MAPK, PKA and PKC, and modulates gene expression via its delicate interaction with other signaling pathways. During endochondral bone formation, TGF- beta acts as a potent inhibitor of the terminal differentiation of epiphyseal growth plate chondrocytes. This effect appears to be primarily mediated by Smad molecules, although MAPK-ATF2 signaling is also involved. The rate of chondrocyte maturation is tightly regulated through the interactions of Smad-mediated signaling, the Wnt signaling pathway, and the transcription factor Runx2. Improving our understanding of the exact mechanisms underlying TGF- beta -mediated signaling pathways and their effects may greatly impact the diagnosis and treatment of many common orthopaedic diseases.
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Affiliation(s)
- Tian-Fang Li
- Center for Musculoskeletal Research, Department of Orthopaedics, University of Rochester School of Medicine, Rochester, NY 14642, USA
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Abstract
A mixed population of lymphocytes from a healthy donor co-existed with an established culture of allogeneic chondrosarcoma cells, during which time the tumor cells changed from malignantly transformed to benign fibroblast-like morphology; from multilayered to a monolayered growth pattern; lost their potency to grow in colonies in soft agar; and showed signs of senescence. A discussion of possible molecular mechanisms for this event is offered. If there are as yet undiscovered lymphokines that can induce reversal of the malignant geno/phenotype, the cognate gene(s) should be cloned for genetic engineering and for the mass production of the corresponding molecular mediators for clinical trials.
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Affiliation(s)
- Joseph G Sinkovics
- Cancer Institue, St. Joseph's Hospital, Department of Medicine, The University of South Florida College of Medicine, 3001 W Dr Martinr Luther King Jr Blvd, Tampa, USA
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