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Garrett EC, Bielawski AM, Ruchti E, Sherer LM, Waghmare I, Hess-Homeier D, McCabe BD, Stowers RS, Certel SJ. The matricellular protein Drosophila Cellular Communication Network Factor is required for synaptic transmission and female fertility. Genetics 2023; 223:iyac190. [PMID: 36602539 PMCID: PMC9991515 DOI: 10.1093/genetics/iyac190] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 01/06/2023] Open
Abstract
Within the extracellular matrix, matricellular proteins are dynamically expressed nonstructural proteins that interact with cell surface receptors, growth factors, and proteases, as well as with structural matrix proteins. The cellular communication network factors family of matricellular proteins serve regulatory roles to regulate cell function and are defined by their conserved multimodular organization. Here, we characterize the expression and neuronal requirement for the Drosophila cellular communication network factor family member. Drosophila cellular communication network factor is expressed in the nervous system throughout development including in subsets of monoamine-expressing neurons. Drosophila cellular communication network factor-expressing abdominal ganglion neurons innervate the ovaries and uterus and the loss of Drosophila cellular communication network factor results in reduced female fertility. In addition, Drosophila cellular communication network factor accumulates at the synaptic cleft and is required for neurotransmission at the larval neuromuscular junction. Analyzing the function of the single Drosophila cellular communication network factor family member will enhance our potential to understand how the microenvironment impacts neurotransmitter release in distinct cellular contexts and in response to activity.
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Affiliation(s)
| | - Ashley M Bielawski
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Evelyne Ruchti
- Brain Mind Institute, Swiss Federal Institute of Technology (EPFL), 1015 Lausanne, Switzerland
| | - Lewis M Sherer
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Indrayani Waghmare
- Department of Cell and Developmental Biology, Program in Developmental Biology, Vanderbilt-Ingram Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - David Hess-Homeier
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Brian D McCabe
- Brain Mind Institute, Swiss Federal Institute of Technology (EPFL), 1015 Lausanne, Switzerland
| | - R Steven Stowers
- Department of Cell Biology and Microbiology, Montana State University, Bozeman, MT 59717, USA
| | - Sarah J Certel
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
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2
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Song MH, Jo Y, Kim YK, Kook H, Jeong D, Park WJ. The TSP-1 domain of the matricellular protein CCN5 is essential for its nuclear localization and anti-fibrotic function. PLoS One 2022; 17:e0267629. [PMID: 35476850 PMCID: PMC9045603 DOI: 10.1371/journal.pone.0267629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 04/12/2022] [Indexed: 02/07/2023] Open
Abstract
The matricellular protein CCN5 exerts anti-fibrotic activity in hearts partly by inducing reverse trans-differentiation of myofibroblasts (MyoFBs) to fibroblasts (FBs). CCN5 consists of three structural domains: an insulin-like growth factor binding protein (IGFBP), a von Willebrand factor type C (VWC), and a thrombospondin type 1 (TSP-1). In this study, we set out to elucidate the roles of these domains in the context of the reverse trans-differentiation of MyoFBs to FBs. First, human cardiac FBs were trans-differentiated to MyoFBs by treatment with TGF-β; this was then reversed by treatment with recombinant human CCN5 protein or various recombinant proteins comprising individual or paired CCN5 domains. Subcellular localization of these recombinant proteins was analyzed by immunocytochemistry, cellular fractionation, and western blotting. Anti-fibrotic activity was also evaluated by examining expression of MyoFB-specific markers, α-SMA and fibronectin. Our data show that CCN5 is taken up by FBs and MyoFBs mainly via clathrin-mediated endocytosis, which is essential for the function of CCN5 during the reverse trans-differentiation of MyoFBs. Furthermore, we showed that the TSP-1 domain is essential and sufficient for endocytosis and nuclear localization of CCN5. However, the TSP-1 domain alone is not sufficient for the anti-fibrotic function of CCN5; either the IGFBP or VWC domain is needed in addition to the TSP-1 domain.
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Affiliation(s)
- Min Ho Song
- College of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Yongjoon Jo
- College of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Young-Kook Kim
- Department of Biochemistry, Chonnam National University Medical School, Hwasun, Jeollanam-do, Republic of Korea
| | - Hyun Kook
- Department of Pharmacology, Chonnam National University Medical School, Hwasun, Jeollanam-do, Republic of Korea
| | - Dongtak Jeong
- Department of Molecular & Life Science, College of Science and Convergence Technology, Hanyang University-ERICA, Ansan, Gyeonggi-do, Republic of Korea
- * E-mail: (WJP); (DJ)
| | - Woo Jin Park
- College of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea
- * E-mail: (WJP); (DJ)
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3
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Kubota S, Kawaki H, Perbal B, Kawata K, Hattori T, Nishida T. Cellular communication network factor 3 in cartilage development and maintenance. J Cell Commun Signal 2021; 15:533-543. [PMID: 34125392 PMCID: PMC8642582 DOI: 10.1007/s12079-021-00629-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/27/2021] [Indexed: 12/30/2022] Open
Abstract
Cellular communication network factor (CCN) 3 is one of the classical members of the CCN family, which are characterized by common molecular structures and multiple functionalities. Although this protein was discovered as a gene product overexpressed in a truncated form in nephroblastoma, recent studies have revealed its physiological roles in the development and homeostasis of mammalian species, in addition to its pathological association with a number of diseases. Cartilage is a tissue that creates most of the bony parts and cartilaginous tissues that constitute the human skeleton, in which CCN3 is also differentially produced to exert its molecular missions therein. In this review article, after the summary of the molecular structure and function of CCN3, recent findings on the regulation of ccn3 expression and the roles of CCN3 in endochondral ossification, cartilage development, maintenance and disorders are introduced with an emphasis on the metabolic regulation and function of this matricellular multifunctional molecule.
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Affiliation(s)
- Satoshi Kubota
- Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8525, Japan.
| | - Harumi Kawaki
- Department of Oral Biochemistry, Asahi University School of Dentistry, Mizuho, Japan
| | | | - Kazumi Kawata
- Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8525, Japan
| | - Takako Hattori
- Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8525, Japan
| | - Takashi Nishida
- Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8525, Japan
- Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School, Okayama, Japan
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4
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Klenotic PA, Zhang C, Lin Z. Emerging roles of CCN proteins in vascular development and pathology. J Cell Commun Signal 2016; 10:251-7. [PMID: 27241177 DOI: 10.1007/s12079-016-0332-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 05/19/2016] [Indexed: 01/02/2023] Open
Abstract
The CCN family of proteins consists of 6 members (CCN1-CCN6) that share conserved functional domains. These matricellular proteins interact with growth factors, extracellular matrix (ECM) proteins, cell surface integrins and other receptors to promote ECM-intracellular signaling. This signaling leads to propagation of a variety of cellular actions, including adhesion, invasion, migration and proliferation within several cell types, including epithelial, endothelial and smooth muscle cells. Though CCNs share significant homology, the function of each is unique due to distinct and cell specific expression patterns. Thus, their correct spatial and temporal expressions are critical during embryonic development, wound healing, angiogenesis and fibrosis. Disruption of these patterns leads to severe development disorders and contributes to the pathological progression of cancers, vascular diseases and chronic inflammatory diseases such as colitis, rheumatoid arthritis and atherosclerosis. While the effects of CCNs are diverse, this review will focus on the role of CCNs within the vasculature during development and in vascular diseases.
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5
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Sawyer AJ, Kyriakides TR. Matricellular proteins in drug delivery: Therapeutic targets, active agents, and therapeutic localization. Adv Drug Deliv Rev 2016; 97:56-68. [PMID: 26763408 DOI: 10.1016/j.addr.2015.12.016] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 12/17/2015] [Accepted: 12/17/2015] [Indexed: 02/06/2023]
Abstract
Extracellular matrix is composed of a complex array of molecules that together provide structural and functional support to cells. These properties are mainly mediated by the activity of collagenous and elastic fibers, proteoglycans, and proteins such as fibronectin and laminin. ECM composition is tissue-specific and could include matricellular proteins whose primary role is to modulate cell-matrix interactions. In adults, matricellular proteins are primarily expressed during injury, inflammation and disease. Particularly, they are closely associated with the progression and prognosis of cardiovascular and fibrotic diseases, and cancer. This review aims to provide an overview of the potential use of matricellular proteins in drug delivery including the generation of therapeutic agents based on the properties and structures of these proteins as well as their utility as biomarkers for specific diseases.
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Re RN. Age-Related Macular Degeneration and Intracrine Biology: An Hypothesis. Ochsner J 2016; 16:502-510. [PMID: 27999510 PMCID: PMC5158158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023] Open
Abstract
This laboratory has studied the intracellular actions of angiotensin II and other signaling proteins that can act in the intracellular space-peptides/proteins we have called intracrines. Moreover, we have suggested that general principles of intracrine action exist and can help explain the progression of some chronic degenerative diseases such as diabetic nephropathy and congestive heart failure. Here, a similar analysis is carried out in the case of age-related macular degeneration. We propose that intracrine mechanisms are operative in this disorder. In particular, we hypothesize that intracrine loops involving renin, angiotensin II, transforming growth factor-beta, vascular endothelial growth factor, bone morphogenetic protein-4, and p53, among other factors, are involved. If this analysis is correct, it suggests a commonality of mechanism linking chronic progressive renal diseases, congestive heart failure, and macular degeneration.
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Affiliation(s)
- Richard N. Re
- Division of Academics–Research, Ochsner Clinic Foundation, New Orleans, LA
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7
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Jeon KI, Phipps RP, Sime PJ, Huxlin KR. Inhibitory effects of PPARγ ligands on TGF-β1-induced CTGF expression in cat corneal fibroblasts. Exp Eye Res 2015; 138:52-8. [PMID: 26142957 DOI: 10.1016/j.exer.2015.06.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [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: 03/20/2015] [Revised: 06/24/2015] [Accepted: 06/30/2015] [Indexed: 12/16/2022]
Abstract
Ligands of Peroxisome Proliferator Activated Receptor gamma (PPARγ) possess strong anti-fibrotic properties in the cornea and several other body tissues. In the cornea, we recently showed this class of molecules to prevent stromal myofibroblast differentiation partially by blocking the actions of p38 mitogen-activated protein kinase (MAPK). However, given the important role assigned to connective tissue growth factor (CTGF) in mediating corneal fibrosis, here we asked whether PPARγ ligands also act by affecting transforming growth factor-β (TGF-β) 1-induced expression of CTGF in cultured corneal fibroblasts. Corneal keratocytes were isolated from young, adult cats and early passage cells were exposed to TGF-β1 with or without the PPARγ ligands Rosiglitazone, Troglitazone and 15d-PGJ2. Western blots were used to assay levels of CTGF and alpha smooth muscle actin (αSMA), a marker of myofibroblast differentiation. CTGF siRNA demonstrated a critical role for CTGF in TGF-β1-mediated myofibroblast differentiation, while exogenously applied CTGF potentiated the pro-fibrogenic effects of TGF-β1. TGF-β1-mediated increases in CTGF and αSMA expression were strongly inhibited by all three PPARγ ligands tested, and by a c-jun N-terminal kinase (JNK) inhibitor. However, while extracellular signal-regulated kinase (ERK) 1/2, protein kinase B (AKT) and p38 MAPK inhibitors also blocked TGF-β1-induced αSMA induction, they did not dampen TGF-β1-induced increases in levels of CTGF. Thus, we conclude that PPARγ ligands block TGF-β1-induced increases in CTGF levels in cat corneal fibroblasts. They appear to do this in addition to their anti-fibrotic effect on p38 MAPK, providing a second intracellular pathway by which PPARγ ligands block αSMA induction.
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Affiliation(s)
- Kye-Im Jeon
- Flaum Eye Institute, University of Rochester, Rochester, NY, USA
| | - Richard P Phipps
- Flaum Eye Institute, University of Rochester, Rochester, NY, USA; Department of Environmental Medicine, University of Rochester, Rochester, NY, USA; Department of Medicine, University of Rochester, Rochester, NY, USA
| | - Patricia J Sime
- Department of Environmental Medicine, University of Rochester, Rochester, NY, USA; Department of Medicine, University of Rochester, Rochester, NY, USA
| | - Krystel R Huxlin
- Flaum Eye Institute, University of Rochester, Rochester, NY, USA; Center for Visual Science, University of Rochester, Rochester, NY, USA.
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Patel P, Brooks C, Seneviratne A, Hess DA, Séguin CA. Investigating microenvironmental regulation of human chordoma cell behaviour. PLoS One 2014; 9:e115909. [PMID: 25541962 PMCID: PMC4277432 DOI: 10.1371/journal.pone.0115909] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 12/01/2014] [Indexed: 12/30/2022] Open
Abstract
The tumour microenvironment is complex and composed of many different constituents, including matricellular proteins such as connective tissue growth factor (CCN2), and is characterized by gradients in oxygen levels. In various cancers, hypoxia and CCN2 promote stem and progenitor cell properties, and regulate the proliferation, migration and phenotype of cancer cells. Our study was aimed at investigating the effects of hypoxia and CCN2 on chordoma cells, using the human U-CH1 cell line. We demonstrate that under basal conditions, U-CH1 cells express multiple CCN family members including CCN1, CCN2, CCN3 and CCN5. Culture of U-CH1 cells in either hypoxia or in the presence of recombinant CCN2 peptide promoted progenitor cell-like characteristics specific to the notochordal tissue of origin. Specifically, hypoxia induced the most robust increase in progenitor-like characteristics in U-CH1 cells, including increased expression of the notochord-associated markers T, CD24, FOXA1, ACAN and CA12, increased cell growth and tumour-sphere formation, and a decrease in the percentage of vacuolated cells present in the heterogeneous population. Interestingly, the effects of recombinant CCN2 peptide on U-CH1 cells were more pronounced under normoxia than hypoxia, promoting increased expression of CCN1, CCN2, CCN3 and CCN5, the notochord-associated markers SOX5, SOX6, T, CD24, and FOXA1 as well as increased tumour-sphere formation. Overall, this study highlights the importance of multiple factors within the tumour microenvironment and how hypoxia and CCN2 may regulate human chordoma cell behaviour.
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Affiliation(s)
- Priya Patel
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Courtney Brooks
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Ayesh Seneviratne
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
- Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada
| | - David A. Hess
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
- Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada
| | - Cheryle A. Séguin
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
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9
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Hoshi K, Kawaki H, Takahashi I, Takeshita N, Seiryu M, Murshid SA, Masuda T, Anada T, Kato R, Kitaura H, Suzuki O, Takano-Yamamoto T. Compressive force-produced CCN2 induces osteocyte apoptosis through ERK1/2 pathway. J Bone Miner Res 2014; 29:1244-57. [PMID: 24155087 DOI: 10.1002/jbmr.2115] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 09/27/2013] [Accepted: 10/08/2013] [Indexed: 11/06/2022]
Abstract
Osteocytes produce various factors that mediate the onset of bone formation and resorption and play roles in maintaining bone homeostasis and remodeling in response to mechanical stimuli. One such factor, CCN2, is thought to play a significant role in osteocyte responses to mechanical stimuli, but its function in osteocytes is not well understood. Here, we showed that CCN2 induces apoptosis in osteocytes under compressive force loading. Compressive force increased CCN2 gene expression and production, and induced apoptosis in osteocytes. Application of exogenous CCN2 protein induced apoptosis, and a neutralizing CCN2 antibody blocked loading-induced apoptosis. We further examined how CCN2 induces loaded osteocyte apoptosis. In loaded osteocytes, extracellular signal-regulated kinase 1/2 (ERK1/2) was activated, and an ERK1/2 inhibitor blocked loading-induced apoptosis. Furthermore, application of exogenous CCN2 protein caused ERK1/2 activation, and the neutralizing CCN2 antibody inhibited loading-induced ERK1/2 activation. Therefore, this study demonstrated for the first time to our knowledge that enhanced production of CCN2 in osteocytes under compressive force loading induces apoptosis through activation of ERK1/2 pathway.
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Affiliation(s)
- Kenji Hoshi
- Division of Orthodontics and Dentofacial Orthopedics, Tohoku University Graduate School of Dentistry, Sendai, Japan
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10
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Yan L, Chaqour B. Cysteine-rich protein 61 (CCN1) and connective tissue growth factor (CCN2) at the crosshairs of ocular neovascular and fibrovascular disease therapy. J Cell Commun Signal 2013; 7:253-63. [PMID: 23740088 DOI: 10.1007/s12079-013-0206-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 05/28/2013] [Indexed: 10/26/2022] Open
Abstract
The vasculature forms a highly branched network investing every organ of vertebrate organisms. The retinal circulation, in particular, is supported by a central retinal artery branching into superficial arteries, which dive into the retina to form a dense network of capillaries in the deeper retinal layers. The function of the retina is highly dependent on the integrity and proper functioning of its vascular network and numerous ocular diseases including diabetic retinopathy, age-related macular degeneration and retinopathy of prematurity are caused by vascular abnormalities culminating in total and sometimes irreversible loss of vision. CCN1 and CCN2 are inducible extracellular matrix (ECM) proteins which play a major role in normal and aberrant formation of blood vessels as their expression is associated with developmental and pathological angiogenesis. Both CCN1 and CCN2 achieve disparate cell-type and context-dependent activities through modulation of the angiogenic and synthetic phenotype of vascular and mesenchymal cells respectively. At the molecular level, CCN1 and CCN2 may control capillary growth and vascular cell differentiation by altering the composition or function of the constitutive ECM proteins, potentiating or interfering with the activity of various ligands and/or their receptors, physically interfering with the ECM-cell surface interconnections, and/or reprogramming gene expression driving cells toward new phenotypes. As such, these proteins emerged as important prognostic markers and potential therapeutic targets in neovascular and fibrovascular diseases of the eye. The purpose of this review is to highlight our current knowledge and understanding of the most recent data linking CCN1 and CCN2 signaling to ocular neovascularization bolstering the potential value of targeting these proteins in a therapeutic context.
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Affiliation(s)
- Lulu Yan
- Department of Cell Biology and Department of Ophthalmology, State University of New York (SUNY) Eye Institute Downstate Medical Center, 450 Clarkson Avenue, Box 5, Brooklyn, NY, 11203, USA
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11
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Tran CM, Shapiro IM, Risbud MV. Molecular regulation of CCN2 in the intervertebral disc: lessons learned from other connective tissues. Matrix Biol 2013; 32:298-306. [PMID: 23567513 DOI: 10.1016/j.matbio.2013.03.006] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 03/28/2013] [Accepted: 03/29/2013] [Indexed: 01/07/2023]
Abstract
Connective tissue growth factor (CCN2/CTGF) plays an important role in extracellular matrix synthesis, especially in skeletal tissues such as cartilage, bone, and the intervertebral disc. As a result there is a growing interest in examining the function and regulation of this important molecule in the disc. This review discusses the regulation of CCN2 by TGF-β and hypoxia, two critical determinants that characterize the disc microenvironment, and discusses known functions of CCN2 in the disc. The almost ubiquitous regulation of CCN2 by TGF-β, including that seen in the disc, emphasizes the importance of the TGF-β-CCN2 relationship, especially in terms of extracellular matrix synthesis. Likewise, the unique cross-talk between CCN2 and HIF-1 in the disc highlights the tissue and niche specific mode of regulation. Taken together the current literature supports an anabolic role for CCN2 in the disc and its involvement in the maintenance of tissue homeostasis during both health and disease. Further studies of CCN2 in this tissue may reveal valuable targets for the biological therapy of disc degeneration.
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Affiliation(s)
- Cassie M Tran
- Department of Orthopaedic Surgery and Graduate Program in Cell and Developmental Biology, Thomas Jefferson University, Philadelphia, USA
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12
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Abstract
The CCN family of proteins includes six members presently known as CCN1, CCN2, CCN3, CCN4, CCN5 and CCN6. These proteins were originally designated CYR61, CTGF, NOV, and WISP-1, WISP-2, WISP-3. Although these proteins share a significant amount of structural features and a partial identity with other large families of regulatory proteins, they exhibit different biological functions. A critical examination of the progress made over the past two decades, since the first CCN proteins were discovered brings me to the conclusion that most of our present knowledge regarding the functions of these proteins was predicted very early after their discovery. In an effort to point out some of the gaps that prevent us to reach a comprehensive view of the functional interactions between CCN proteins, it is necessary to reconsider carefully data that was already published and put aside, either because the scientific community was not ready to accept them, or because they were not fitting with the « consensus » when they were published. This review article points to avenues that were not attracting the attention that they deserved. However, it is quite obvious that the six members of this unique family of tetra-modular proteins must act in concert, either simultaneously or sequentially, on the same sites or at different times in the life of living organisms. A better understanding of the spatio-temporal regulation of CCN proteins expression requires considering the family as such, not as a set of single proteins related only by their name. As proposed in this review, there is enough convincing pieces of evidence, at the present time, in favor of these proteins playing a role in the coordination of multiple signaling pathways, and constituting a Centralized Communication Network. Deciphering the hierarchy of regulatory circuits involved in this complex system is an important challenge for the near future. In this article, I would like to briefly review the concept of a CCN family of proteins and critically examine the progress made over the past 10 years in the understanding of their biological functions and involvement in both normal and pathological processes.
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Mason RM. Fell-Muir lecture: Connective tissue growth factor (CCN2) -- a pernicious and pleiotropic player in the development of kidney fibrosis. Int J Exp Pathol 2012; 94:1-16. [PMID: 23110747 DOI: 10.1111/j.1365-2613.2012.00845.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 08/21/2012] [Indexed: 01/01/2023] Open
Abstract
Connective tissue growth factor (CTGF, CCN2) is a member of the CCN family of matricellular proteins. It interacts with many other proteins, including plasma membrane proteins, modulating cell function. It is expressed at low levels in normal adult kidney cells but is increased in kidney diseases, playing important roles in inflammation and in the development of glomerular and interstitial fibrosis in chronic disease. This review reports the evidence for its expression in human and animal models of chronic kidney disease and summarizes data showing that anti-CTGF therapy can successfully attenuate fibrotic changes in several such models, suggesting that therapies targeting CTGF and events downstream of it in renal cells may be useful for the treatment of human kidney fibrosis. Connective tissue growth factor stimulates the development of fibrosis in the kidney in many ways including activating cells to increase extracellular matrix synthesis, inducing cell cycle arrest and hypertrophy, and prolonging survival of activated cells. The relationship between CTGF and the pro-fibrotic factor TGFβ is examined and mechanisms by which CTGF promotes signalling by the latter are discussed. No specific cellular receptors for CTGF have been discovered but it interacts with and activates several plasma membrane proteins including low-density lipoprotein receptor-related protein (LRP)-1, LRP-6, tropomyosin-related kinase A, integrins and heparan sulphate proteoglycans. Intracellular signalling and downstream events triggered by such interactions are reviewed. Finally, the relationships between CTGF and several anti-fibrotic factors, such as bone morphogenetic factor-4 (BMP4), BMP7, hepatocyte growth factor, CCN3 and Oncostatin M, are discussed. These may determine whether injured tissue heals or progresses to fibrosis.
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Affiliation(s)
- Roger M Mason
- Renal Section, Department of Medicine, Imperial College London, London, UK.
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Zuehlke J, Ebenau A, Krueger B, Goppelt-Struebe M. Vectorial secretion of CTGF as a cell-type specific response to LPA and TGF-β in human tubular epithelial cells. Cell Commun Signal 2012; 10:25. [PMID: 22938209 PMCID: PMC3503564 DOI: 10.1186/1478-811x-10-25] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 08/16/2012] [Indexed: 12/23/2022] Open
Abstract
UNLABELLED BACKGROUND Increased expression of the pro-fibrotic protein connective tissue growth factor (CTGF) has been detected in injured kidneys and elevated urinary levels of CTGF are discussed as prognostic marker of chronic kidney disease. There is evidence that epithelial cells lining the renal tubular system contribute to uptake and secretion of CTGF. However, the role of different types of tubular epithelial cells in these processes so far has not been addressed in primary cultures of human cells. RESULTS Tubular epithelial cells of proximal and distal origin were isolated from human kidneys and cultured as polarized cells in insert wells. The pro-fibrotic stimuli lysophosphatidic acid (LPA) and transforming growth factor β (TGF-β) were used to induce CTGF secretion.LPA activated CTGF secretion in proximal tubular cells when applied from either the apical or the basolateral side as shown by immunocytochemistry. CTGF was secreted exclusively to the apical side. Signaling pathways activated by LPA included MAP kinase and Rho kinase signaling. TGF-β applied from either side also stimulated CTGF secretion primarily to the apical side with little basolateral release.Interestingly, TGF-β activation induced different signaling pathways depending on the side of TGF-β application. Smad signaling was almost exclusively activated from the basolateral side most prominently in cells of distal origin. Only part of these cells also synthesized CTGF indicating that Smad activation alone was not sufficient for CTGF induction. MAP kinases were involved in apical TGF-β-mediated activation of CTGF synthesis in proximal cells and a subset of epithelial cells of distal origin. This subpopulation of distal tubular cells was also able to internalize recombinant apical CTGF, in addition to proximal cells which were the main cells to take up exogenous CTGF. CONCLUSIONS Analysis of polarized human primary renal epithelial cells in a transwell system shows that vectorial secretion of the pro-fibrotic protein CTGF depends on the cell type, the stimulus and the signaling pathway activated. In all conditions, CTGF was secreted mainly to the apical side upon TGF-β and LPA treatment and therefore, likely contributes to increased urinary CTGF levels in vivo. Moreover, CTGF secreted basolaterally may be active as paracrine pro-fibrotic mediator.
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Affiliation(s)
- Jonathan Zuehlke
- Department of Nephrology and Hypertension, Friedrich-Alexander Universität Erlangen-Nürnberg, Loschgestrasse 8, Erlangen 91054, Germany
| | - Astrid Ebenau
- Department of Nephrology and Hypertension, Friedrich-Alexander Universität Erlangen-Nürnberg, Loschgestrasse 8, Erlangen 91054, Germany
| | - Bettina Krueger
- Department of Cellular and Molecular Physiology, Friedrich-Alexander Universität Erlangen-Nürnberg, Waldstrasse 6, Erlangen, 91054, Germany
| | - Margarete Goppelt-Struebe
- Department of Nephrology and Hypertension, Friedrich-Alexander Universität Erlangen-Nürnberg, Loschgestrasse 8, Erlangen 91054, Germany
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Lipson KE, Wong C, Teng Y, Spong S. CTGF is a central mediator of tissue remodeling and fibrosis and its inhibition can reverse the process of fibrosis. Fibrogenesis Tissue Repair 2012; 5:S24. [PMID: 23259531 PMCID: PMC3368796 DOI: 10.1186/1755-1536-5-s1-s24] [Citation(s) in RCA: 394] [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] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
CTGF is a secreted matricellular protein with very complex biology. It has been shown to modulate many signaling pathways leading to cell adhesion and migration, angiogenesis, myofibroblast activation, and extracellular matrix deposition and remodeling, which together lead to tissue remodeling and fibrosis. It has been reported in the literature that inhibition of CTGF expression by siRNA prevents CCl4-induced liver fibrosis and can reverse fibrosis when administered after significant collagen deposition is observed. A monoclonal antibody to CTGF that is currently in clinical development (FG-3019) has demonstrated the ability to reverse vascular stiffening and improve cardiac function in a rat model of diabetic complications. FG-3019 has also exhibited activity in a murine radiation-induced pulmonary fibrosis model. When FG-3019 was administered to mice after a significant radiation-induced increase in lung density could be observed by CT imaging, the density of the lungs was observed to decrease over the period during which the antibody was administered and to remain stable after therapy had ceased. When considered together, these data indicate that inhibition of CTGF can prevent and reverse the process of fibrosis.
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Affiliation(s)
| | - Carol Wong
- FibroGen, Inc., 409 Illinois St., San Francisco, CA 94158, USA
| | - Yuchin Teng
- FibroGen, Inc., 409 Illinois St., San Francisco, CA 94158, USA
| | - Suzanne Spong
- FibroGen, Inc., 409 Illinois St., San Francisco, CA 94158, USA
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Fuchshofer R, Ullmann S, Zeilbeck LF, Baumann M, Junglas B, Tamm ER. Connective tissue growth factor modulates podocyte actin cytoskeleton and extracellular matrix synthesis and is induced in podocytes upon injury. Histochem Cell Biol 2011; 136:301-19. [DOI: 10.1007/s00418-011-0844-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/11/2011] [Indexed: 12/19/2022]
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Abstract
The matricellular protein connective tissue growth factor (CTGF, CCN2) is overexpressed in several forms of cancer and may represent a novel target in anti-cancer therapy. However, whether CCN2 is expressed in melanoma cells is unknown. The highly metastatic murine melanoma cell line B16(F10) was used for our studies. Real time polymerase chain reaction analysis was used to detect mRNA expression of CCN1, CCN2, CCN3 and CCN4 in Western blot and immunofluorescence analyses were used to detect CCN2 protein. Inhibitors of signal transduction cascades were used to probe the mechanism underlying CCN2 expression in B16(F10) cells. CCN2 was expressed in B16(F10) cells, and was reduced by the FAK/src inhibitor PP2 and the MEK/ERK inhibitor U0126 indicating that CCN2 acts downstream of these pathways in B16(F10) murine melanoma cells. Expression of CCN1, CCN3 and CCN4 was not reduced by PP2 or U0126; in fact, expression of CCN4 mRNA was elevated by PP2 or U0126 treatment. To our surprise, CCN2 protein was detected in the nuclei of B16(F10) cells, and was undetectable in the cytoplasm. CCN2 was expressed in B16(F10) melanoma cells, adding to the list of cancer cells in which CCN2 is expressed. Of the CCN family members tested, only CCN2 is downstream of the highly oncogenic MEK/ERK pathway. CCN2 should be further evaluated for a possible role in melanoma growth and progression.
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Affiliation(s)
- Wei Sha
- Department of Dentistry, Schulich School of Medicine of Dentistry, Dental Sciences Building, University of Western Ontario, London, ON, Canada, N6A 5C1
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18
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Kular L, Pakradouni J, Kitabgi P, Laurent M, Martinerie C. The CCN family: A new class of inflammation modulators? Biochimie 2011; 93:377-88. [DOI: 10.1016/j.biochi.2010.11.010] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 11/24/2010] [Indexed: 01/12/2023]
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Sabbah M, Prunier C, Ferrand N, Megalophonos V, Lambein K, De Wever O, Nazaret N, Lachuer J, Dumont S, Redeuilh G. CCN5, a novel transcriptional repressor of the transforming growth factor β signaling pathway. Mol Cell Biol 2011; 31:1459-69. [PMID: 21262769 DOI: 10.1128/MCB.01316-10] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
CCN5 is a member of the CCN (connective tissue growth factor/cysteine-rich 61/nephroblastoma overexpressed) family and was identified as an estrogen-inducible gene in estrogen receptor-positive cell lines. However, the role of CCN5 in breast carcinogenesis remains unclear. We report here that the CCN5 protein is localized mostly in the cytoplasm and in part in the nucleus of human tumor breast tissue. Using a heterologous transcription assay, we demonstrate that CCN5 can act as a transcriptional repressor presumably through association with histone deacetylase 1 (HDAC1). Microarray gene expression analysis showed that CCN5 represses expression of genes associated with epithelial-mesenchymal transition (EMT) as well as expression of key components of the transforming growth factor β (TGF-β) signaling pathway, prominent among them TGF-βRII receptor. We show that CCN5 is recruited to the TGF-βRII promoter, thereby providing a mechanism by which CCN5 restricts transcription of the TGF-βRII gene. Consistent with this finding, CCN5, we found, functions to suppress TGF-β-induced transcriptional responses and invasion that is concomitant with EMT. Thus, our data uncovered CCN5 as a novel transcriptional repressor that plays an important role in regulating tumor progression functioning, at least in part, by inhibiting the expression of genes involved in the TGF-β signaling cascade that is known to promote EMT.
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Wiesman KC, Wei L, Baughman C, Russo J, Gray MR, Castellot JJ. CCN5, a secreted protein, localizes to the nucleus. J Cell Commun Signal 2010; 4:91-8. [PMID: 20531984 PMCID: PMC2876239 DOI: 10.1007/s12079-010-0087-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Accepted: 02/23/2010] [Indexed: 10/19/2022] Open
Abstract
CCN5, a member of the CCN family of growth factors, inhibits the proliferation and migration of smooth muscle cells in cell culture and animal models. Expressed in both embryonic and adult tissues, CCN5 exhibits a matricellular localization pattern characteristic of secreted proteins that are closely associated with the cell surface. In addition to this observed expression pattern, immunohistochemical evidence suggests the presence of nuclear CCN5 in some cells. To determine if CCN5 localizes to the nucleus we performed immunofluorescence, confocal imaging, and cell fractionation to corroborate the immunohistochemical observations. After confirming the presence of nuclear CCN5 using four independent experimental methods, we identified a single putative nuclear localization signal in the von Willebrand factor C domain of mouse and rat CCN5. Site directed mutagenesis of the three basic amino acids in the putative nuclear localization sequence did not prevent nuclear localization of CCN5 in four different cell types, suggesting that CCN5 nuclear transport is not mediated by the only canonical nuclear localization signal present in the primary amino acid sequence. Future work will address the mechanism of nuclear localization and the function of nuclear versus secreted CCN5.
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Affiliation(s)
- Kristina C. Wiesman
- Department of Pharmacology and Experimental Therapeutics, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111 USA
| | - Lan Wei
- Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111 USA
| | - Cassandra Baughman
- Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111 USA
| | - Joshua Russo
- Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111 USA
| | - Mark R. Gray
- Department of Anatomy and Cell Biology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111 USA
| | - John J. Castellot
- Department of Pharmacology and Experimental Therapeutics, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111 USA
- Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111 USA
- Department of Anatomy and Cell Biology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111 USA
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Sin WC, Tse M, Planque N, Perbal B, Lampe PD, Naus CC. Matricellular protein CCN3 (NOV) regulates actin cytoskeleton reorganization. J Biol Chem 2009; 284:29935-44. [PMID: 19706598 DOI: 10.1074/jbc.m109.042630] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
CCN3 (NOV), a putative ligand for integrin receptors, is tightly associated with the extracellular matrix and mediates diverse cellular functions, including cell adhesion and proliferation. CCN3 has been shown to negatively regulate growth although it promotes migration in a cell type-specific manner. In this study, overexpression of CCN3 reduces growth and increases intercellular adhesion of breast cancer cells. Interestingly, CCN3 overexpression also led to the formation of multiple pseudopodia that are enriched in actin, CCN3, and vinculin. Breast cancer cells preincubated with exogenous CCN3 protein also induced the same phenotype, indicating that secreted CCN3 is sufficient to induce changes in cell morphology. Surprisingly, extracellular CCN3 is internalized to the early endosomes but not to the membrane protrusions, suggesting pseudopodia-enriched CCN3 may derive from a different source. The presence of an intracellular variant of CCN3 will be consistent with our finding that the cytoplasmic tail of the gap junction protein connexin43 (Cx43) associates with CCN3. Cx43 is a channel protein permitting intercellular communication to occur. However, neither the channel properties nor the protein levels of Cx43 are affected by the CCN3 protein. In contrast, CCN3 proteins are down-regulated in the absence of Cx43. Finally, we showed that overexpression of CCN3 increases the activity of the small GTPase Rac1, thereby revealing a pathway that links Cx43 directly to actin reorganization.
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Affiliation(s)
- Wun-Chey Sin
- Department of Cellular and Physiological Sciences and The Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T1Z3, Canada.
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Junglas B, Yu AHL, Welge-Lüssen U, Tamm ER, Fuchshofer R. Connective tissue growth factor induces extracellular matrix deposition in human trabecular meshwork cells. Exp Eye Res 2009; 88:1065-75. [PMID: 19450452 DOI: 10.1016/j.exer.2009.01.008] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Revised: 12/23/2008] [Accepted: 01/16/2009] [Indexed: 10/21/2022]
Abstract
The major structural change in the human trabecular meshwork (TM) of eyes with primary open-angle glaucoma (POAG) is an increase in extracellular matrix (ECM) in the juxtacanalicular region of the TM. There is evidence that treatment with TGF-beta2 causes an induction of ECM deposition in cultured human TM cells and that TGF-beta2 is causatively involved in the JCT ECM increase in POAG. In the present study, we investigated the effects of connective tissue growth factor (CTGF) on the biology of cultured human TM cells. CTGF is a downstream mediator of TGF-beta2-signaling, which is expressed at high amounts in the human TM in situ. HEK293 cells were transfected with an eukaryotic expression plasmid containing the coding sequences of human CTGF. Secreted CTGF was isolated and purified by chromatography. Primary human TM cells were incubated for 24 h with CTGF at concentrations of 2.5-100 ng/ml. Following treatment with CTGF, the expression of various ECM components that are expressed in the JCT, matrix metalloproteinases (MMPs) and integrins was investigated by real-time RT-PCR and western blot analyses. In addition, the activity of MMPs was investigated by gelatine zymography. The effect of CTGF silencing on TGF-beta2-induced gene expression was investigated by transfection of immortalized HTM cells with CTGF-specific small interfering (si)RNA before TGF-beta2 treatment. CTGF-treated human TM cells showed an increase in the expression of fibronectin, collagen types I, III, IV and VI, as well as in the integrin subunits aV and beta1. Lower concentrations of CTGF caused an autoinduction of CTGF expression. No effects were observed on the expression and activity of MMP-2, MMP-9 and plasminogen activator inhibitor-1 (PAI-1). Transfection with CTGF-specific siRNA inhibited the TGF-beta2-induced upregulation of CTGF and fibronectin. Our results indicate that treatment of human TM cells with recombinant CTGF causes distinct changes in gene expression and that CTGF is a critical mediator of the effects of TGF-beta2 on ECM synthesis in human TM cells. An intriguing aspect supported by the data of the present work is that the pharmacologic modulation of CTGF might be a useful approach to develop novel therapeutic strategies to prevent or to reverse the structural changes that occur in the TM of eyes with POAG.
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Affiliation(s)
- Benjamin Junglas
- Institute of Human Anatomy and Embryology, University of Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany
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Gray MR, Malmquist JA, Sullivan M, Blea M, Castellot JJ Jr. CCN5 Expression in mammals. II. Adult rodent tissues. J Cell Commun Signal 2007; 1:145-58. [PMID: 18481204 DOI: 10.1007/s12079-007-0013-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Accepted: 09/25/2007] [Indexed: 12/31/2022] Open
Abstract
CCN5 is a secreted heparin- and estrogen-regulated matricellular protein that inhibits vertebrate smooth muscle cell proliferation and motility. CCN5 is expressed throughout murine embryonic development in most organs and tissues. However, after embryonic development is complete, we hypothesized that CCN5 distribution would be largely restricted to small set of tissues, including smooth muscle cells of the arteries, uterus, airway, and digestive tract. Because CCN5 inhibits proliferation of smooth muscle cells in vitro, it might function to prevent excessive growth in vivo. In contrast, another member of the CCN family, CCN2, promotes smooth muscle cell proliferation in vitro, and thus it was expected that its expression levels would be low in uninjured normal adult tissues. Frozen sections from adult tissues and organs were analyzed immunohistochemically using anti-CCN5 and anti-CCN2 antibodies. Both proteins were detected in arteries, the uterus, bronchioles, and the digestive tract as expected, and also in many other tissues including the pancreas, spleen, liver, skeletal muscle, ovary, testis, thymus, brain, olfactory epithelium, and kidney. CCN5 and CCN2 protein was found in smooth muscle, endothelial cells, epithelial cells, skeletal muscle, cells of the nervous system, and numerous other cell types. In many cells, both CCN5 and CCN2 was present in the nucleus. Rather than having opposite patterns of localization, CCN5 and CCN2 often had similar sites of expression. The wide distribution of both CCN5 and CCN2 suggests that both proteins have additional biological functions beyond those previously identified in specific cellular and pathological models.
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25
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Jones JA, Gray MR, Oliveira BE, Koch M, Castellot JJ. CCN5 expression in mammals : I. Embryonic and fetal tissues of mouse and human. J Cell Commun Signal 2007; 1:127-43. [PMID: 18481203 PMCID: PMC2275877 DOI: 10.1007/s12079-007-0012-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Accepted: 09/06/2007] [Indexed: 02/08/2023] Open
Abstract
The six proteins of the CCN family have important roles in development, angiogenesis, cell motility, proliferation, and other fundamental cell processes. To date, CCN5 distribution in developing rodents and humans has not been mapped comprehensively. CCN5 strongly inhibits adult smooth muscle cell proliferation and motility. Its anti-proliferative action predicts that CCN5 would not be present in developing tissues until the proliferation phase of tissue morphogenesis is complete. However, estrogen induces CCN5 expression in epithelial and smooth muscle cells, suggesting that CCN5 might be widely expressed in embryonic tissues exposed to high levels of estrogen. 9-16 day murine embryos and fetuses and 3-7 month human fetal tissues were analyzed by immunohistochemistry. CCN5 was detected in nearly all developing tissues. CCN5 protein expression was initially present in most tissues, and at later times in development tissue-specific expression differences were observed. CCN5 expression was particularly strong in vascular tissues, cardiac muscle, bronchioles, myotendinous junctions, and intestinal smooth muscle and epithelium. CCN5 expression was initially absent in bone cartilaginous forms but was increasingly expressed during bone endochondral ossification. Widespread CCN5 mRNA expression was detected in GD14.5 mice. Although CCN2 and CCN5 protein expression patterns in some adult pathologic conditions are inversely expressed, this expression pattern was not found in developing mouse and human tissues. The widespread expression pattern of CCN5 in most embryonic and fetal tissues suggests a diverse range of functions for CCN5.
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Affiliation(s)
- Jennifer A. Jones
- Program in Cell, Molecular, and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA USA
| | - Mark R. Gray
- Department of Anatomy and Cell Biology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111 USA
| | - Beatriz Enes Oliveira
- Program in Cell, Molecular, and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA USA
- Instituto de Ciencias Biomedicas Abel Salazar, 4099-003 Porto, Portugal
| | - Manuel Koch
- Center for Biochemistry, Department of Dermatology, Medical Faculty, University of Cologne, Cologne, Germany
| | - John J. Castellot
- Program in Cell, Molecular, and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA USA
- Department of Anatomy and Cell Biology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111 USA
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Planque N. Nuclear trafficking of secreted factors and cell-surface receptors: new pathways to regulate cell proliferation and differentiation, and involvement in cancers. Cell Commun Signal 2006; 4:7. [PMID: 17049074 PMCID: PMC1626074 DOI: 10.1186/1478-811x-4-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [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: 07/28/2006] [Accepted: 10/18/2006] [Indexed: 12/14/2022] Open
Abstract
Secreted factors and cell surface receptors can be internalized by endocytosis and translocated to the cytoplasm. Instead of being recycled or proteolysed, they sometimes translocate to the nucleus. Nuclear import generally involves a nuclear localization signal contained either in the secreted factor or its transmembrane receptor, that is recognized by the importins machinery. In the nucleus, these molecules regulate transcription of specific target genes by direct binding to transcription factors or general coregulators. In addition to the transcription regulation, nuclear secreted proteins and receptors seem to be involved in other important processes for cell life and cellular integrity such as DNA replication, DNA repair and RNA metabolism. Nuclear secreted proteins and transmembrane receptors now appear to induce new signaling pathways to regulate cell proliferation and differentiation. Their nuclear localization is often transient, appearing only during certain phases of the cell cycle. Nuclear secreted and transmembrane molecules regulate the proliferation and differentiation of a large panel of cell types during embryogenesis and adulthood and are also potentially involved in wound healing. Secreted factors such as CCN proteins, EGF, FGFs and their receptors are often detected in the nucleus of cancer cells. Nuclear localization of these molecules has been correlated with tumor progression and poor prognosis for patient survival. Nuclear growth factors and receptors may be responsible for resistance to radiotherapy.
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Affiliation(s)
- Nathalie Planque
- Laboratoire d'Oncologie Virale et Moléculaire, Université Paris7-Denis Diderot, UFR de Biochimie, 2 place Jussieu, 75005 Paris, France.
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Abstract
1. Severe persistent asthma is accompanied by structural changes in the airway, referred to as remodelling. The mechanisms driving airway remodelling are poorly understood. 2. Transforming growth factor (TGF)-beta is increased in the airways of patients with asthma. Many of the effects of TGF-beta are mediated by connective tissue growth factor (CTGF). 3. Overexpression of CTGF is linked to many fibrotic diseases, but its exact role in airway remodelling is unknown. 4. Connective tissue growth factor mediates cell adhesion, migration, proliferation, survival, extracellular matrix synthesis and has a role in angiogenesis. 5. Current asthma therapies do not inhibit CTGF induction. 6. Understanding the mechanisms underlying the role of CTGF in airway remodelling may lead to new therapeutic strategies for asthma.
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Affiliation(s)
- Janette K Burgess
- Department of Pharmacology, University of Sydney and Woolcock Institute of Medical Research, Sydney, New South Wales, Australia.
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Abstract
Connective tissue growth factor (CTGF) is implicated as a factor promoting tissue fibrosis in several disorders, including diabetic nephropathy. However, the molecular mechanism(s) by which it functions is not known. CTGF rapidly activates several intracellular signaling molecules in human mesangial cells (HMC), including extracellular signal-related kinase 1/2, Jun NH(2)-terminal kinase, protein kinase B, CaMK II, protein kinase Calpha, and protein kinase Cdelta, suggesting that it functions via a signaling receptor. Treating HMC with CTGF stimulated tyrosine phosphorylation of proteins 75 to 80 and 140 to 180 kD within 10 min, and Western blot analysis of anti-phosphotyrosine immunoprecipitates identified the neurotrophin receptor TrkA (molecular weight approximately 140 kD). Cross-linking rCTGF to cell surface proteins with 3,3'-dithiobis(sulfosuccinimidylpropionate) revealed that complexes formed with TrkA and with the general neurotrophin co-receptor p75(NTR). rCTGF stimulated phosphorylation of TrkA (tyr 490, 674/675). K252a, a known selective inhibitor of Trk, blocked this phosphorylation, CTGF-induced activation of signaling proteins, and CTGF-dependent induction of the transcription factor TGF-beta-inducible early gene in HMC. It is concluded that TrkA serves as a tyrosine kinase receptor for CTGF.
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Affiliation(s)
- Nadia Abdel Wahab
- Renal Section, Division of Medicine, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 ONN, UK.
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Chowdhury I, Chaqour B. Regulation of connective tissue growth factor (CTGF/CCN2) gene transcription and mRNA stability in smooth muscle cells. Involvement of RhoA GTPase and p38 MAP kinase and sensitivity to actin dynamics. ACTA ACUST UNITED AC 2004; 271:4436-50. [PMID: 15560785 DOI: 10.1111/j.1432-1033.2004.04382.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [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: 11/27/2022]
Abstract
Connective tissue growth factor (CTGF/CCN2) is an immediate early gene-encoded polypeptide modulating cell growth and collagen synthesis. The importance of CTGF/CCN2 function is highlighted by its disregulation in fibrotic disorders. In this study, we investigated the regulation and signaling pathways that are required for various stimuli of intracellular signaling events to induce the expression of the endogenous CTGF/CCN2 gene in smooth muscle cells. Incubation with the bioactive lysolipid sphingosine 1-phosphate (S1P) produced a threefold increase, whereas stimulation with either fetal bovine serum or anisomycin induced an even stronger activation (eightfold) of CTGF/CCN2 expression. Using a combination of pathway-specific inhibitors and mutant forms of signaling molecules, we found that S1P- and fetal bovine serum-induced CTGF/CCN2 expression were dependent on both RhoA GTPase and p38 mitogen-activated protein kinase transduction pathways, whereas the effects of anisomycin largely involved p38 and phosphatidyl inositol 3-kinase signaling mechanisms. However, activation via these signaling events was absolutely dependent on actin cytoskeleton integrity. In particular, RhoA-dependent regulation of the CTGF/CCN2 gene was concomitant to increased polymerization of actin microfilaments resulting in decreased G- to F-actin ratio and appeared to be achieved at the transcriptional level. The p38 signaling pathway was RhoA-independent and led to CTGF/CCN2 mRNA stabilization. Use of actin-binding drugs showed that the actual physical state of monomeric G-actin is a critical determinant for CTGF/CCN2 gene induction. These data indicate that distinct cytoskeletally based signaling events within the intracellular signaling machinery affect either transcriptionally or post-transcriptionally the expression of the CTGF/CCN2 gene in smooth muscle cells.
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Affiliation(s)
- Ibrul Chowdhury
- Department of Anatomy and Cell Biology, University of Pennsylvania, PA, USA
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Abstract
PURPOSE OF REVIEW Connective tissue growth factor (CCN2) has recently received much attention as a possible key determinant of progressive renal fibrosis. However, the mechanism(s) by which this growth factor functions is not known. The purpose of this review is to summarize and discuss the recent findings regarding the possible mechanisms involved. RECENT FINDINGS Emerging evidence from in-vitro studies of renal cells indicates that connective tissue growth factor is a crucial mediator for transforming growth factor-beta-induced cellular dysfunction, manifest by increased cellular hypertrophy, synthesis of extracellular matrix proteins and their deposition and assembly around the cells. Indeed, recent evidence suggests that the interrelationship between connective tissue growth factor and transforming growth factor-beta is stronger than first thought. While transforming growth factor-beta induces the expression of connective tissue growth factor, the latter plays a key role in both bioactivation of latent transforming growth factor-beta and the promotion of its Smad signalling activity. SUMMARY Connective tissue growth factor is clearly implicated in the pathogenesis of progressive renal disease. Although there is much to learn about the production, function, and mechanism of action of connective tissue growth factor, some progress has been made in understanding the molecular basis of its relationship with transforming growth factor-beta. Elucidating the signal transduction pathways activated by connective tissue growth factor will also definitely help to clarify other actions of connective tissue growth factor which may be independent of transforming growth factor-beta. Because of the inflammatory and immunosuppressive properties of transforming growth factor-beta, connective tissue growth factor seems to be an attractive alternative therapeutic target for combating renal fibrosis.
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Affiliation(s)
- Nadia Abdel Wahab
- Cell and Molecular Biology Section, Division of Biomedical Sciences, Faculty of Medicine, Imperial College London, London, England, UK.
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Abstract
The CCN (CYR61 [Cystein-rich61]/CTGF [connective tissue growth factor]/NOV [Nephroblastoma overexpressed]) proteins constitute a family of regulatory factors involved in many aspects of cell proliferation and differentiation. An increasing body of evidence indicates that abnormal expression of the CCN proteins is associated to tumourgenesis. The multimodular architecture of the CCN proteins, and the production of truncated isoforms in tumours, raise interesting questions regarding the participation of each individual module to the various biological properties of these proteins. In this article, we review the current data regarding the involvement of CCN proteins in tumourigenesis. We also attempt to provide structural basis for the stimulatory and inhibitory functions of the full length and truncated CCN proteins that are expressed in various tumour tissues.
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Affiliation(s)
- Nathalie Planque
- Laboratoire d'Oncologie Virale et Moléculaire, UFR de Biochimie, Université Paris 7 – D. Diderot, 2 Place Jussieu- 75 005 PARIS – France
| | - Bernard Perbal
- Laboratoire d'Oncologie Virale et Moléculaire, UFR de Biochimie, Université Paris 7 – D. Diderot, 2 Place Jussieu- 75 005 PARIS – France
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Han JS, Macarak E, Rosenbloom J, Chung KC, Chaqour B. Regulation of Cyr61/CCN1 gene expression through RhoA GTPase and p38MAPK signaling pathways. Eur J Biochem 2003; 270:3408-21. [PMID: 12899698 DOI: 10.1046/j.1432-1033.2003.03723.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cysteine-rich protein 61 (Cyr61/CCN1) is an angiogenic factor and a member of a family of growth factor-inducible immediate-early genes with functions in cell adhesion, proliferation and differentiation. We investigated the regulatory mechanisms and signaling pathways involved in Cyr61/CCN1gene activation in smooth muscle cells. Treatment of these cells with sphingosine 1-phosphate (S1P), a bioactive lysolipid, increased rapidly but transiently the expression of the Cyr61/CCN1 gene at both the mRNA and protein levels. Cyr61/CCN1 mRNA stability was not altered but the transcription rate of the Cyr61/CCN1 gene was increased fivefold in isolated nuclei from S1P-stimulated cells indicating that the level of control is primarily transcriptional. Transfection experiments showed that a 936-bp promoter fragment of the human Cyr61/CCN1 gene is functional and induces a reporter gene activity in S1P-treated cells. Using a combination of cis-element mutagenesis and expression of dominant negative inhibitors of transcription factors, we showed that both a CRE and AP-1 site and their cognate transcription factors, cAMP response element binding protein (CREB) and AP-1, were responsible for the promoter activity in S1P-stimulated cells. Furthermore, by using either pharmacological inhibitors or active forms of known signaling molecules, we showed that inducible Cyr61/CCN1 gene expression occurs through RhoA GTPase and that additional signaling through the p38 pathway is required. In particular, p38 seems to regulate Cyr61/CCN1 promoter activity through modulation of phosphorylation of CREB and the CREB kinase, MSK1. These findings demonstrate the transcriptional regulation of the Cyr61/CCN1 gene and provide clues to the signaling molecules and transcription factors involved in such regulation.
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Affiliation(s)
- Ji-Soo Han
- University of Pennsylvania, Department of Anatomy and Cell Biology, Philadelphia, PA 19104, USA
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33
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Affiliation(s)
- U Ueberham
- Paul Flechsig Institute for Brain Research, Department of Neuroanatomy, University of Leipzig, Jahnallee 59, D-04109 Leipzig, Germany.
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Sawai K, Mori K, Mukoyama M, Sugawara A, Suganami T, Koshikawa M, Yahata K, Makino H, Nagae T, Fujinaga Y, Yokoi H, Yoshioka T, Yoshimoto A, Tanaka I, Nakao K. Angiogenic protein Cyr61 is expressed by podocytes in anti-Thy-1 glomerulonephritis. J Am Soc Nephrol 2003; 14:1154-63. [PMID: 12707386 DOI: 10.1097/01.asn.0000060576.61218.3d] [Citation(s) in RCA: 28] [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: 12/20/2022] Open
Abstract
Dynamic recovery of glomerular structure occurs after severe glomerular damage in anti-Thy-1 glomerulonephritis (Thy-1 GN), but its mechanism remains to be investigated. To identify candidate genes possibly involved in glomerular reconstruction, screening was performed for genes that are specifically expressed by podocytes and are upregulated in glomeruli of Thy-1 GN. Among them, cysteine-rich protein 61 (Cyr61 or CCN1), a soluble angiogenic protein belonging to the CCN family, was identified. By Northern blot analysis, Cyr61 mRNA was markedly upregulated in glomeruli of Thy-1 GN from day 3 through day 7, when mesangial cell migration was most prominent. By in situ hybridization and immunohistochemistry, Cyr61 mRNA and protein were expressed by proximal straight tubules and afferent and efferent arterioles in normal rat kidneys and were intensely upregulated at podocytes in Thy-1 GN. Platelet-derived growth factor-BB (PDGF-BB) and transforming growth factor-beta1 (TGF-beta1), of which the gene expression in the glomeruli of Thy-1 GN was upregulated in similar time course as Cyr61, induced Cyr61 mRNA expression in cultured podocytes. Furthermore, supernatant of Cyr61-overexpressing cells inhibited PDGF-induced mesangial cell migration. In conclusion, it is shown that Cyr61 is strongly upregulated at podocytes in Thy-1 GN possibly by PDGF and TGF-beta. Cyr61 may be involved in glomerular remodeling as a factor secreted from podocytes to inhibit mesangial cell migration.
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Affiliation(s)
- Kazutomo Sawai
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
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Abstract
Connective tissue growth factor (CTGF) has recently received much attention as a possible key determinant of progressive fibrosis and excessive scarring and also of wound repair, neoangiogenesis, bone formation and embryonic development. CTGF is also up regulated in numerous fibrotic diseases, including atherosclerosis and lung-, skin-, pancreas-, liver- and kidney-fibrosis. TGFbeta induces CTGF through different signaling pathways and a specific TGFbeta responsive element in the CTGF promoter. CTGF is thought to act both as a profibrotic marker and as a downstream effector of TGFbeta by mediating at least some of its profibrotic activities. CTGF is an interesting target for future antifibrotic therapies as it is conceivable that inhibition of CTGF might block the profibrotic effects of TGFbeta, without affecting TGFbeta's anti-proliferative and immunosuppressive effects. In addition to TGFbeta, a number of other regulators of CTGF expression have been identified, including vascular endothelial growth factor, tumor necrosis factor alpha, shear stress, cell stretch and static pressure, H(2)O(2), O(2) and NO. In addition to trans-regulatory mechanisms, specific transcription factor binding sites in the CTGF promoter, as well as 3'untranslated region (UTR) regulatory sequences have been identified that are important for basal and induced CTGF expression. Outlining the mechanisms that underlie CTGF gene regulation in normal and fibrotic cells, might help design of future intervention strategies aiming at targeted specific interference with CTGF expression at sites of progressive fibrosis. In addition, alternative therapies targeting CTGF effects are proposed which might lead to a favorable outcome of wound repair and fibrosis.
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Affiliation(s)
- Ingrid E Blom
- Department of Pathology, H04.312, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
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