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Samuvel DJ, Lemasters JJ, Chou CJ, Zhong Z. LP340, a novel histone deacetylase inhibitor, decreases liver injury and fibrosis in mice: role of oxidative stress and microRNA-23a. Front Pharmacol 2024; 15:1386238. [PMID: 38828459 PMCID: PMC11140137 DOI: 10.3389/fphar.2024.1386238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 04/24/2024] [Indexed: 06/05/2024] Open
Abstract
Effective therapy for liver fibrosis is lacking. Here, we examined whether LP340, the lead candidate of a new-generation of hydrazide-based HDAC1,2,3 inhibitors (HDACi), decreases liver fibrosis. Liver fibrosis was induced by CCl4 treatment and bile duct ligation (BDL) in mice. At 6 weeks after CCl4, serum alanine aminotransferase increased, and necrotic cell death and leukocyte infiltration occurred in the liver. Tumor necrosis factor-α and myeloperoxidase markedly increased, indicating inflammation. After 6 weeks, α-smooth muscle actin (αSMA) and collagen-1 expression increased by 80% and 575%, respectively, indicating hepatic stellate cell (HSC) activation and fibrogenesis. Fibrosis detected by trichrome and Sirius-red staining occurred primarily in pericentral regions with some bridging fibrosis in liver sections. 4-Hydroxynonenal adducts (indicator of oxidative stress), profibrotic cytokine transforming growth factor-β (TGFβ), and TGFβ downstream signaling molecules phospho-Smad2/3 also markedly increased. LP340 attenuated indices of liver injury, inflammation, and fibrosis markedly. Moreover, Ski-related novel protein-N (SnoN), an endogenous inhibitor of TGFβ signaling, decreased, whereas SnoN expression suppressor microRNA-23a (miR23a) increased markedly. LP340 (0.05 mg/kg, ig., daily during the last 2 weeks of CCl4 treatment) decreased 4-hydroxynonenal adducts and miR23a production, blunted SnoN decreases, and inhibited the TGFβ/Smad signaling. By contrast, LP340 had no effect on matrix metalloproteinase-9 expression. LP340 increased histone-3 acetylation but not tubulin acetylation, indicating that LP340 inhibited Class-I but not Class-II HDAC in vivo. After BDL, focal necrosis, inflammation, ductular reactions, and portal and bridging fibrosis occurred at 2 weeks, and αSMA and collagen-1 expression increased by 256% and 560%, respectively. LP340 attenuated liver injury, ductular reactions, inflammation, and liver fibrosis. LP340 also decreased 4-hydroxynonenal adducts and miR23a production, prevented SnoN decreases, and inhibited the TGFβ/Smad signaling after BDL. In vitro, LP340 inhibited immortal human hepatic stellate cells (hTERT-HSC) activation in culture (αSMA and collagen-1 expression) as well as miR23a production, demonstrating its direct inhibitory effects on HSC. In conclusions, LP340 is a promising therapy for both portal and pericentral liver fibrosis, and it works by inhibiting oxidative stress and decreasing miR23a.
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Affiliation(s)
- Devadoss J. Samuvel
- Departments of Drug Discovery and Biomedical Sciences, Charleston, SC, United States
| | - John J. Lemasters
- Departments of Drug Discovery and Biomedical Sciences, Charleston, SC, United States
- Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, United States
| | - C. James Chou
- Departments of Drug Discovery and Biomedical Sciences, Charleston, SC, United States
- Lydex Pharmaceuticals, Mount Pleasant, SC, United States
| | - Zhi Zhong
- Departments of Drug Discovery and Biomedical Sciences, Charleston, SC, United States
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2
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Smad-dependent pathways in the infarcted and failing heart. Curr Opin Pharmacol 2022; 64:102207. [DOI: 10.1016/j.coph.2022.102207] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 02/10/2022] [Accepted: 02/22/2022] [Indexed: 02/08/2023]
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3
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He W, Chen Z, Li H, Wu W, He P, Zhong D, Jiang Y, Cheng W, Xu Z, Li J. Decreased phosphorylation facilitates the degradation of the endogenous protective molecule c-Ski in vascular smooth muscle cells. Cell Signal 2021; 87:110116. [PMID: 34390788 DOI: 10.1016/j.cellsig.2021.110116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/04/2021] [Accepted: 08/06/2021] [Indexed: 01/04/2023]
Abstract
The dysfunction of vascular smooth muscle cells (VSMCs) is critical for atherosclerosis (AS) progression. Autophagy is indispensable during phenotypic switching and proliferation of VSMCs, contribute to AS development. Cellular Sloan-Kettering Institute (c-Ski), the repressor of TGF-β signaling, is involved in diverse physiological and pathological processes. We previously defined c-Ski also as an endogenous protective molecule against AS via inhibiting abnormal proliferation and autophagy of VSMCs. However, the endogenous level of c-Ski in VSMCs is markedly decreased during the progression of AS, so that the protective effect is drastically weakened. Elucidating the molecular mechanisms is key to the understanding of AS development and treatment. We determined that oxidized low-density lipoprotein (ox-LDL) and platelet-derived growth factor (PDGF) directly induced the degradation of c-Ski protein, closely associated with reducing its phosphorylation. Serine383 (S383) was identified as the crucial phosphorylation site for stabilizing protein expression and nuclear location of c-Ski, which was responsible for its transcriptional suppression of autophagy-related genes. Decreased S383 phosphorylation facilitated nuclear export and degradation of c-Ski, thereby lessened its inhibitory effect on induction of autophagy genes. These findings provide a novel view of c-Ski modification and function modulation under some vascular injury factors, which point to a new potential therapeutic strategy by targeting c-Ski.
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Affiliation(s)
- Wenhui He
- Department of Biochemistry and Molecular Biology, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Zongtao Chen
- Health Management Centre, The First Affiliated Hospital of Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Haoyang Li
- Brigade 5 of Medical Undergraduate, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | | | - Ping He
- Department of Cardiac Surgery, The First Affiliated Hospital of Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Dan Zhong
- Department of Biochemistry and Molecular Biology, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Yu Jiang
- Department of Biochemistry and Molecular Biology, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Wei Cheng
- Department of Cardiac Surgery, The First Affiliated Hospital of Army Medical University (Third Military Medical University), Chongqing 400038, China.
| | - Zhizhen Xu
- Department of Biochemistry and Molecular Biology, Army Medical University (Third Military Medical University), Chongqing 400038, China.
| | - Jun Li
- Department of Cardiac Surgery, The First Affiliated Hospital of Army Medical University (Third Military Medical University), Chongqing 400038, China.
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Cappelli C, Sepulveda H, Rivas S, Pola V, Urzúa U, Donoso G, Sagredo E, Carrero D, Casanova-Ortiz E, Sagredo A, González M, Manterola M, Nardocci G, Armisén R, Montecino M, Marcelain K. Ski Is Required for Tri-Methylation of H3K9 in Major Satellite and for Repression of Pericentromeric Genes: Mmp3, Mmp10 and Mmp13, in Mouse Fibroblasts. J Mol Biol 2020; 432:3222-3238. [PMID: 32198114 DOI: 10.1016/j.jmb.2020.03.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 02/23/2020] [Accepted: 03/11/2020] [Indexed: 11/27/2022]
Abstract
Several mechanisms directing a rapid transcriptional reactivation of genes immediately after mitosis have been described. However, little is known about the maintenance of repressive signals during mitosis. In this work, we address the role of Ski in the repression of gene expression during M/G1 transition in mouse embryonic fibroblasts (MEFs). We found that Ski localises as a distinct pair of dots at the pericentromeric region of mitotic chromosomes, and the absence of the protein is related to high acetylation and low tri-methylation of H3K9 in pericentromeric major satellite. Moreover, differential expression assays in early G1 cells showed that the presence of Ski is significantly associated with repression of genes localised nearby to pericentromeric DNA. In mitotic cells, chromatin immunoprecipitation assays confirmed the association of Ski to major satellite and the promoters of the most repressed genes: Mmp3, Mmp10 and Mmp13. These genes are at pericentromeric region of chromosome 9. In these promoters, the presence of Ski resulted in increased H3K9 tri-methylation levels. This Ski-dependent regulation is also observed during interphase. Consequently, Mmp activity is augmented in Ski-/- MEFs. Altogether, these data indicate that association of Ski with the pericentromeric region of chromosomes during mitosis is required to maintain the silencing bookmarks of underlying chromatin.
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Affiliation(s)
- Claudio Cappelli
- Departamento de Oncología Básico Clínica. Facultad de Medicina, Universidad de Chile, Santiago, Chile; Instituto de Bioquimica y Microbiologia, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Hugo Sepulveda
- Instituto de Ciencias Biomédicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Solange Rivas
- Departamento de Oncología Básico Clínica. Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Víctor Pola
- Departamento de Oncología Básico Clínica. Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Ulises Urzúa
- Departamento de Oncología Básico Clínica. Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Gerardo Donoso
- Departamento de Oncología Básico Clínica. Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Eduardo Sagredo
- Departamento de Oncología Básico Clínica. Facultad de Medicina, Universidad de Chile, Santiago, Chile; Centro de Genética y Genómica, Instituto de Ciencias e Innovación en Medicina, Facultad de Medicina Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | - David Carrero
- Departamento de Oncología Básico Clínica. Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Emmanuel Casanova-Ortiz
- Departamento de Oncología Básico Clínica. Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Alfredo Sagredo
- Departamento de Oncología Básico Clínica. Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Marisel González
- Departamento de Oncología Básico Clínica. Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Marcia Manterola
- Instituto de Ciencias Biomédicas. Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Gino Nardocci
- Instituto de Ciencias Biomédicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile; FONDAP Center for Genome Regulation, Santiago, Chile
| | - Ricardo Armisén
- Departamento de Oncología Básico Clínica. Facultad de Medicina, Universidad de Chile, Santiago, Chile; Centro de Genética y Genómica, Instituto de Ciencias e Innovación en Medicina, Facultad de Medicina Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Martin Montecino
- Instituto de Ciencias Biomédicas, Facultad de Medicina y Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile; FONDAP Center for Genome Regulation, Santiago, Chile
| | - Katherine Marcelain
- Departamento de Oncología Básico Clínica. Facultad de Medicina, Universidad de Chile, Santiago, Chile.
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Landry N, Kavosh MS, Filomeno KL, Rattan SG, Czubryt MP, Dixon IMC. Ski drives an acute increase in MMP-9 gene expression and release in primary cardiac myofibroblasts. Physiol Rep 2019; 6:e13897. [PMID: 30488595 PMCID: PMC6429976 DOI: 10.14814/phy2.13897] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 09/24/2018] [Accepted: 09/26/2018] [Indexed: 12/12/2022] Open
Abstract
Many etiologies of heart disease are characterized by expansion and remodeling of the cardiac extracellular matrix (ECM or matrix) which results in cardiac fibrosis. Cardiac fibrosis is mediated in cardiac fibroblasts by TGF‐β1/R‐Smad2/3 signaling. Matrix component proteins are synthesized by activated resident cardiac fibroblasts known as myofibroblasts (MFB). These events are causal to heart failure with diastolic dysfunction and reduced cardiac filling. We have shown that exogenous Ski, a TGF‐β1/Smad repressor, localizes in the cellular nucleus and deactivates cardiac myofibroblasts. This deactivation is associated with reduction of myofibroblast marker protein expression in vitro, including alpha smooth muscle actin (α‐SMA) and extracellular domain‐A (ED‐A) fibronectin. We hypothesize that Ski also acutely regulates MMP expression in cardiac MFB. While acute Ski overexpression in cardiac MFB in vitro was not associated with any change in intracellular MMP‐9 protein expression versus LacZ‐treated controls,exogenous Ski caused elevated MMP‐9 mRNA expression and increased MMP‐9 protein secretion versus controls. Zymographic analysis revealed increased MMP‐9‐specific gelatinase activity in myofibroblasts overexpressing Ski versus controls. Moreover, Ski expression was attended by reduced paxillin and focal adhesion kinase phosphorylation (FAK ‐ Tyr 397) versus controls. As myofibroblasts are hypersecretory and less motile relative to fibroblasts, Ski's reduction of paxillin and FAK expression may reflect the relative deactivation of myofibroblasts. Thus, in addition to its known antifibrotic effects, Ski overexpression elevates expression and extracellular secretion/release of MMP‐9 and thus may facilitate internal cytoskeletal remodeling as well as extracellular ECM components. Further, as acute TGF‐β1 treatment of primary cardiac MFB is known to cause rapid translocation of Ski to the nucleus, our data support an autoregulatory role for Ski in mediating cardiac ECM accumulation.
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Affiliation(s)
- Natalie Landry
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Morvarid S Kavosh
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Krista L Filomeno
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Sunil G Rattan
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Michael P Czubryt
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Ian M C Dixon
- Department of Physiology and Pathophysiology, Institute of Cardiovascular Sciences, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
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Taguchi L, Miyakuni K, Morishita Y, Morikawa T, Fukayama M, Miyazono K, Ehata S. c-Ski accelerates renal cancer progression by attenuating transforming growth factor β signaling. Cancer Sci 2019; 110:2063-2074. [PMID: 30972853 PMCID: PMC6550129 DOI: 10.1111/cas.14018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 04/03/2019] [Accepted: 04/07/2019] [Indexed: 12/11/2022] Open
Abstract
Although transforming growth factor beta (TGF‐β) is known to be involved in the pathogenesis and progression of many cancers, its role in renal cancer has not been fully investigated. In the present study, we examined the role of TGF‐β in clear cell renal carcinoma (ccRCC) progression in vitro and in vivo. First, expression levels of TGF‐β signaling pathway components were examined. Microarray and immunohistochemical analyses showed that the expression of c‐Ski, a transcriptional corepressor of Smad‐dependent TGF‐β and bone morphogenetic protein (BMP) signaling, was higher in ccRCC tissues than in normal renal tissues. Next, a functional analysis of c‐Ski effects was carried out. Bioluminescence imaging of renal orthotopic tumor models demonstrated that overexpression of c‐Ski in human ccRCC cells promoted in vivo tumor formation. Enhancement of tumor formation was also reproduced by the introduction of a dominant‐negative mutant TGF‐β type II receptor into ccRCC cells. In contrast, introduction of the BMP signaling inhibitor Noggin failed to accelerate tumor formation, suggesting that the tumor‐promoting effect of c‐Ski depends on the inhibition of TGF‐β signaling rather than of BMP signaling. Finally, the molecular mechanism of the tumor‐suppressive role of TGF‐β was assessed. Although TGF‐β signaling did not affect tumor angiogenesis, apoptosis of ccRCC cells was induced by TGF‐β. Taken together, these findings suggest that c‐Ski suppresses TGF‐β signaling in ccRCC cells, which, in turn, attenuates the tumor‐suppressive effect of TGF‐β.
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Affiliation(s)
- Luna Taguchi
- Department of Molecular Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kosuke Miyakuni
- Department of Molecular Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yasuyuki Morishita
- Department of Molecular Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Teppei Morikawa
- Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masashi Fukayama
- Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kohei Miyazono
- Department of Molecular Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shogo Ehata
- Department of Molecular Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Department of Medical Genomics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Environmental Science Center, The University of Tokyo, Tokyo, Japan
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7
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Tecalco-Cruz AC, Ríos-López DG, Vázquez-Victorio G, Rosales-Alvarez RE, Macías-Silva M. Transcriptional cofactors Ski and SnoN are major regulators of the TGF-β/Smad signaling pathway in health and disease. Signal Transduct Target Ther 2018; 3:15. [PMID: 29892481 PMCID: PMC5992185 DOI: 10.1038/s41392-018-0015-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 02/16/2018] [Accepted: 03/15/2018] [Indexed: 12/19/2022] Open
Abstract
The transforming growth factor-β (TGF-β) family plays major pleiotropic roles by regulating many physiological processes in development and tissue homeostasis. The TGF-β signaling pathway outcome relies on the control of the spatial and temporal expression of >500 genes, which depend on the functions of the Smad protein along with those of diverse modulators of this signaling pathway, such as transcriptional factors and cofactors. Ski (Sloan-Kettering Institute) and SnoN (Ski novel) are Smad-interacting proteins that negatively regulate the TGF-β signaling pathway by disrupting the formation of R-Smad/Smad4 complexes, as well as by inhibiting Smad association with the p300/CBP coactivators. The Ski and SnoN transcriptional cofactors recruit diverse corepressors and histone deacetylases to repress gene transcription. The TGF-β/Smad pathway and coregulators Ski and SnoN clearly regulate each other through several positive and negative feedback mechanisms. Thus, these cross-regulatory processes finely modify the TGF-β signaling outcome as they control the magnitude and duration of the TGF-β signals. As a result, any alteration in these regulatory mechanisms may lead to disease development. Therefore, the design of targeted therapies to exert tight control of the levels of negative modulators of the TGF-β pathway, such as Ski and SnoN, is critical to restore cell homeostasis under the specific pathological conditions in which these cofactors are deregulated, such as fibrosis and cancer. Proteins that repress molecular signaling through the transforming growth factor-beta (TGF-β) pathway offer promising targets for treating cancer and fibrosis. Marina Macías-Silva and colleagues from the National Autonomous University of Mexico in Mexico City review the ways in which a pair of proteins, called Ski and SnoN, interact with downstream mediators of TGF-β to inhibit the effects of this master growth factor. Aberrant levels of Ski and SnoN have been linked to diverse range of diseases involving cell proliferation run amok, and therapies that regulate the expression of these proteins could help normalize TGF-β signaling to healthier physiological levels. For decades, drug companies have tried to target the TGF-β pathway, with limited success. Altering the activity of these repressors instead could provide a roundabout way of remedying pathogenic TGF-β activity in fibrosis and oncology.
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Affiliation(s)
- Angeles C Tecalco-Cruz
- 1Instituto de Investigaciones Biomédicas at Universidad Nacional Autónoma de México, Mexico city, 04510 Mexico
| | - Diana G Ríos-López
- 2Instituto de Fisiología Celular at Universidad Nacional Autónoma de México, Mexico city, 04510 Mexico
| | | | - Reyna E Rosales-Alvarez
- 2Instituto de Fisiología Celular at Universidad Nacional Autónoma de México, Mexico city, 04510 Mexico
| | - Marina Macías-Silva
- 2Instituto de Fisiología Celular at Universidad Nacional Autónoma de México, Mexico city, 04510 Mexico
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8
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Chaikuad A, Bullock AN. Structural Basis of Intracellular TGF-β Signaling: Receptors and Smads. Cold Spring Harb Perspect Biol 2016; 8:cshperspect.a022111. [PMID: 27549117 DOI: 10.1101/cshperspect.a022111] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Stimulation of the transforming growth factor β (TGF-β) family receptors activates an intracellular phosphorylation-dependent signaling cascade that culminates in Smad transcriptional activation and turnover. Structural studies have identified a number of allosteric mechanisms that control the localization, conformation, and oligomeric state of the receptors and Smads. Such mechanisms dictate the ordered binding of substrate and adaptor proteins that determine the directionality of the signaling process. Activation of the pathway has been illustrated by the various structures of the receptor-activated Smads (R-Smads) with SARA, Smad4, and YAP, respectively, whereas mechanisms of down-regulation have been elucidated by the structural complexes of FKBP12, Ski, and Smurf1. Interesting parallels have emerged between the R-Smads and the Forkhead-associated (FHA) and interferon regulatory factor (IRF)-associated domains, as well as the Hippo pathway. However, important questions remain as to the mechanism of Smad-independent signaling.
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Affiliation(s)
- Apirat Chaikuad
- Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Alex N Bullock
- Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, United Kingdom
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9
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Abstract
Transforming growth factor β (TGF-β) and related growth factors are secreted pleiotropic factors that play critical roles in embryogenesis and adult tissue homeostasis by regulating cell proliferation, differentiation, death, and migration. The TGF-β family members signal via heteromeric complexes of type I and type II receptors, which activate members of the Smad family of signal transducers. The main attribute of the TGF-β signaling pathway is context-dependence. Depending on the concentration and type of ligand, target tissue, and developmental stage, TGF-β family members transmit distinct signals. Deregulation of TGF-β signaling contributes to developmental defects and human diseases. More than a decade of studies have revealed the framework by which TGF-βs encode a context-dependent signal, which includes various positive and negative modifiers of the principal elements of the signaling pathway, the receptors, and the Smad proteins. In this review, we first introduce some basic components of the TGF-β signaling pathways and their actions, and then discuss posttranslational modifications and modulatory partners that modify the outcome of the signaling and contribute to its context-dependence, including small noncoding RNAs.
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Affiliation(s)
- Akiko Hata
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California 94143
| | - Ye-Guang Chen
- The State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
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10
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Abstract
Transforming growth factor β (TGF-β) family members signal via heterotetrameric complexes of type I and type II dual specificity kinase receptors. The activation and stability of the receptors are controlled by posttranslational modifications, such as phosphorylation, ubiquitylation, sumoylation, and neddylation, as well as by interaction with other proteins at the cell surface and in the cytoplasm. Activation of TGF-β receptors induces signaling via formation of Smad complexes that are translocated to the nucleus where they act as transcription factors, as well as via non-Smad pathways, including the Erk1/2, JNK and p38 MAP kinase pathways, and the Src tyrosine kinase, phosphatidylinositol 3'-kinase, and Rho GTPases.
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Affiliation(s)
- Carl-Henrik Heldin
- Ludwig Institute for Cancer Research Ltd., Science for Life Laboratory, Uppsala University, SE-751 24 Uppsala, Sweden
| | - Aristidis Moustakas
- Ludwig Institute for Cancer Research Ltd., Science for Life Laboratory, Uppsala University, SE-751 24 Uppsala, Sweden Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, SE-751 23 Uppsala, Sweden
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11
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Abstract
In cells responding to extracellular polypeptide ligands, regulatory mechanisms at the level of cell surface receptors are increasingly seen to define the nature of the ligand-induced signaling responses. Processes that govern the levels of receptors at the plasma membrane, including posttranslational modifications, are crucial to ensure receptor function and specify the downstream signals. Indeed, extracellular posttranslational modifications of the receptors help define stability and ligand binding, while intracellular modifications mediate interactions with signaling mediators and accessory proteins that help define the nature of the signaling response. The use of various molecular biology and biochemistry techniques, based on chemical crosslinking, e.g., biotin or radioactive labeling, immunofluorescence to label membrane receptors and flow cytometry, allows for quantification of changes of cell surface receptor presentation. Here, we discuss recent progress in our understanding of the regulation of TGF-β receptors, i.e., the type I (TβRI) and type II (TβRII) TGF-β receptors, and describe basic methods to identify and quantify TGF-β cell surface receptors.
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Affiliation(s)
- Erine H Budi
- Department of Cell and Tissue Biology, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Programs in Cell Biology, and Developmental and Stem Cell Biology, University of California, San Francisco, CA, USA
| | - Jian Xu
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry of USC, University of Southern California, Los Angeles, CA, USA
| | - Rik Derynck
- Department of Cell and Tissue Biology, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Programs in Cell Biology, and Developmental and Stem Cell Biology, University of California, San Francisco, CA, USA.
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12
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YANG HAIPING, ZHAN LEI, YANG TIANJIE, WANG LONGQIANG, LI CHANG, ZHAO JUN, LEI ZHE, LI XIANGDONG, ZHANG HONGTAO. Ski prevents TGF-β-induced EMT and cell invasion by repressing SMAD-dependent signaling in non-small cell lung cancer. Oncol Rep 2015; 34:87-94. [DOI: 10.3892/or.2015.3961] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 03/13/2015] [Indexed: 11/06/2022] Open
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13
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Vázquez-Victorio G, Caligaris C, Del Valle-Espinosa E, Sosa-Garrocho M, González-Arenas NR, Reyes-Cruz G, Briones-Orta MA, Macías-Silva M. Novel regulation of Ski protein stability and endosomal sorting by actin cytoskeleton dynamics in hepatocytes. J Biol Chem 2015; 290:4487-99. [PMID: 25561741 DOI: 10.1074/jbc.m114.579532] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
TGF-β-induced antimitotic signals are highly regulated during cell proliferation under normal and pathological conditions, such as liver regeneration and cancer. Up-regulation of the transcriptional cofactors Ski and SnoN during liver regeneration may favor hepatocyte proliferation by inhibiting TGF-β signals. In this study, we found a novel mechanism that regulates Ski protein stability through TGF-β and G protein-coupled receptor (GPCR) signaling. Ski protein is distributed between the nucleus and cytoplasm of normal hepatocytes, and the molecular mechanisms controlling Ski protein stability involve the participation of actin cytoskeleton dynamics. Cytoplasmic Ski is partially associated with actin and localized in cholesterol-rich vesicles. Ski protein stability is decreased by TGF-β/Smads, GPCR/Rho signals, and actin polymerization, whereas GPCR/cAMP signals and actin depolymerization promote Ski protein stability. In conclusion, TGF-β and GPCR signals differentially regulate Ski protein stability and sorting in hepatocytes, and this cross-talk may occur during liver regeneration.
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Affiliation(s)
- Genaro Vázquez-Victorio
- From the Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México, D. F. 04510, México and
| | - Cassandre Caligaris
- From the Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México, D. F. 04510, México and
| | - Eugenio Del Valle-Espinosa
- From the Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México, D. F. 04510, México and
| | - Marcela Sosa-Garrocho
- From the Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México, D. F. 04510, México and
| | - Nelly R González-Arenas
- From the Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México, D. F. 04510, México and
| | - Guadalupe Reyes-Cruz
- the Departamento de Biología Celular, CINVESTAV-IPN, México, D. F. 07000, México
| | - Marco A Briones-Orta
- From the Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México, D. F. 04510, México and
| | - Marina Macías-Silva
- From the Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México, D. F. 04510, México and
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Chen Z, Li W, Ning Y, Liu T, Shao J, Wang Y. Ski diminishes TGF-β1-induced myofibroblast phenotype via up-regulating Meox2 expression. Exp Mol Pathol 2014; 97:542-9. [PMID: 25445500 DOI: 10.1016/j.yexmp.2014.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 09/26/2014] [Accepted: 11/04/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVE The aim of the present work was to investigate the mechanism of transforming growth factor (TGF)-β1 and Sloan-Kettering Institute (Ski) in the pathogenesis of hypertrophic scars (HS). BACKGROUND Wound healing is an inherent process, but the aberrant wound healing of skin injury may lead to HS. There has been growing evidence suggesting a role for TGF-β1 and Ski in the pathogenesis of fibrosis. MATERIAL AND METHODS The MTT assay was used to detect the cell proliferation induced by TGF-β1. The Ski gene was transduced into cells with an adenovirus, and then the function of Ski in cell proliferation and differentiation was observed. Ski mRNA levels were measured by RT-PCR. Western blotting was used to detect the protein expression of α-SMA, E-cadherin, Meox1, Meox2, Zeb1 and Zeb2. RESULTS TGF-β1 can promote human skin fibroblast (HSF) cell proliferation in a time-dependent manner, but the promoting effect could be suppressed by Ski. TGF-β1 also induces the formation of the myofibroblast phenotype and the effect of TGF-β1 could be diminished by Ski. Also, Ski modulates the cardiac myofibroblast phenotype and function through suppression of Zeb2 by up-regulating the expression of Meox2. CONCLUSIONS Ski diminishes the myofibroblast phenotype induced by TGF-β1 through the suppression of Zeb2 by up-regulating the expression of Meox2.
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Affiliation(s)
- Zhaowei Chen
- Department of Burns and Plastic Surgery, Liao Cheng Hospital, Liao Cheng 252000, China.
| | - Wenjing Li
- Department of Burns and Plastic Surgery, Liao Cheng Hospital, Liao Cheng 252000, China
| | - Yan Ning
- Department of Burns and Plastic Surgery, Liao Cheng Hospital, Liao Cheng 252000, China
| | - Tong Liu
- Department of Burns and Plastic Surgery, Liao Cheng Hospital, Liao Cheng 252000, China
| | - Jingxiang Shao
- Department of Burns and Plastic Surgery, Liao Cheng Hospital, Liao Cheng 252000, China
| | - Yaojun Wang
- Department of Burns and Skin Surgery, Xi Jing Hospital, Xian 710032, China
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15
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Cunnington RH, Northcott JM, Ghavami S, Filomeno KL, Jahan F, Kavosh MS, Davies JJL, Wigle JT, Dixon IMC. The Ski-Zeb2-Meox2 pathway provides a novel mechanism for regulation of the cardiac myofibroblast phenotype. J Cell Sci 2013; 127:40-9. [PMID: 24155330 DOI: 10.1242/jcs.126722] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cardiac fibrosis is linked to fibroblast-to-myofibroblast phenoconversion and proliferation but the mechanisms underlying this are poorly understood. Ski is a negative regulator of TGF-β-Smad signaling in myofibroblasts, and might redirect the myofibroblast phenotype back to fibroblasts. Meox2 could alter TGF-β-mediated cellular processes and is repressed by Zeb2. Here, we investigated whether Ski diminishes the myofibroblast phenotype by de-repressing Meox2 expression and function through repression of Zeb2 expression. We show that expression of Meox1 and Meox2 mRNA and Meox2 protein is reduced during phenoconversion of fibroblasts to myofibroblasts. Overexpression of Meox2 shifts the myofibroblasts into fibroblasts, whereas the Meox2 DNA-binding mutant has no effect on myofibroblast phenotype. Overexpression of Ski partially restores Meox2 mRNA expression levels to those in cardiac fibroblasts. Expression of Zeb2 increased during phenoconversion and Ski overexpression reduces Zeb2 expression in first-passage myofibroblasts. Furthermore, expression of Meox2 is decreased in scar following myocardial infarction, whereas Zeb2 protein expression increases in the infarct scar. Thus Ski modulates the cardiac myofibroblast phenotype and function through suppression of Zeb2 by upregulating the expression of Meox2. This cascade might regulate cardiac myofibroblast phenotype and presents therapeutic options for treatment of cardiac fibrosis.
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Affiliation(s)
- Ryan H Cunnington
- Department of Physiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
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16
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Wu D, Shen YH, Russell L, Coselli JS, LeMaire SA. Molecular mechanisms of thoracic aortic dissection. J Surg Res 2013; 184:907-24. [PMID: 23856125 PMCID: PMC3788606 DOI: 10.1016/j.jss.2013.06.007] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 05/31/2013] [Accepted: 06/05/2013] [Indexed: 12/22/2022]
Abstract
Thoracic aortic dissection (TAD) is a highly lethal vascular disease. In many patients with TAD, the aorta progressively dilates and ultimately ruptures. Dissection formation, progression, and rupture cannot be reliably prevented pharmacologically because the molecular mechanisms of aortic wall degeneration are poorly understood. The key histopathologic feature of TAD is medial degeneration, a process characterized by smooth muscle cell depletion and extracellular matrix degradation. These structural changes have a profound impact on the functional properties of the aortic wall and can result from excessive protease-mediated destruction of the extracellular matrix, altered signaling pathways, and altered gene expression. Review of the literature reveals differences in the processes that lead to ascending versus descending and sporadic versus hereditary TAD. These differences add to the complexity of this disease. Although tremendous progress has been made in diagnosing and treating TAD, a better understanding of the molecular, cellular, and genetic mechanisms that cause this disease is necessary to developing more effective preventative and therapeutic treatment strategies.
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Affiliation(s)
- Darrell Wu
- Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, BCM 390, One Baylor Plaza, Houston, Texas 77030
- Department of Cardiovascular Surgery, Texas Heart Institute at St. Luke’s Episcopal Hospital, 6770 Bertner Ave., Houston, Texas 77030
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, BCM 335, One Baylor Plaza, Houston, Texas 77030
| | - Ying H. Shen
- Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, BCM 390, One Baylor Plaza, Houston, Texas 77030
- Department of Cardiovascular Surgery, Texas Heart Institute at St. Luke’s Episcopal Hospital, 6770 Bertner Ave., Houston, Texas 77030
| | - Ludivine Russell
- Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, BCM 390, One Baylor Plaza, Houston, Texas 77030
- Department of Cardiovascular Surgery, Texas Heart Institute at St. Luke’s Episcopal Hospital, 6770 Bertner Ave., Houston, Texas 77030
| | - Joseph S. Coselli
- Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, BCM 390, One Baylor Plaza, Houston, Texas 77030
- Department of Cardiovascular Surgery, Texas Heart Institute at St. Luke’s Episcopal Hospital, 6770 Bertner Ave., Houston, Texas 77030
| | - Scott A. LeMaire
- Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, BCM 390, One Baylor Plaza, Houston, Texas 77030
- Department of Cardiovascular Surgery, Texas Heart Institute at St. Luke’s Episcopal Hospital, 6770 Bertner Ave., Houston, Texas 77030
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, BCM 335, One Baylor Plaza, Houston, Texas 77030
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17
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Zhu Q, Kim YH, Wang D, Oh SP, Luo K. SnoN facilitates ALK1-Smad1/5 signaling during embryonic angiogenesis. ACTA ACUST UNITED AC 2013; 202:937-50. [PMID: 24019535 PMCID: PMC3776356 DOI: 10.1083/jcb.201208113] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In endothelial cells, two type I receptors of the transforming growth factor β (TGF-β) family, ALK1 and ALK5, coordinate to regulate embryonic angiogenesis in response to BMP9/10 and TGF-β. Whereas TGF-β binds to and activates ALK5, leading to Smad2/3 phosphorylation and inhibition of endothelial cell proliferation and migration, BMP9/10 and TGF-β also bind to ALK1, resulting in the activation of Smad1/5. SnoN is a negative regulator of ALK5 signaling through the binding and repression of Smad2/3. Here we uncover a positive role of SnoN in enhancing Smad1/5 activation in endothelial cells to promote angiogenesis. Upon ligand binding, SnoN directly bound to ALK1 on the plasma membrane and facilitated the interaction between ALK1 and Smad1/5, enhancing Smad1/5 phosphorylation. Disruption of this SnoN-Smad interaction impaired Smad1/5 activation and up-regulated Smad2/3 activity. This resulted in defective angiogenesis and arteriovenous malformations, leading to embryonic lethality at E12.5. Thus, SnoN is essential for TGF-β/BMP9-dependent biological processes by its ability to both positively and negatively modulate the activities of Smad-dependent pathways.
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Affiliation(s)
- Qingwei Zhu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
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18
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Hernández-Damián J, Tecalco-Cruz AC, Ríos-López DG, Vázquez-Victorio G, Vázquez-Macías A, Caligaris C, Sosa-Garrocho M, Flores-Pérez B, Romero-Avila M, Macías-Silva M. Downregulation of SnoN oncoprotein induced by antibiotics anisomycin and puromycin positively regulates transforming growth factor-β signals. Biochim Biophys Acta Gen Subj 2013; 1830:5049-58. [PMID: 23872350 DOI: 10.1016/j.bbagen.2013.07.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 06/26/2013] [Accepted: 07/09/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND SnoN and Ski proteins function as Smad transcriptional corepressors and are implicated in the regulation of diverse cellular processes such as proliferation, differentiation and transformation. Transforming growth factor-β (TGF-β) signaling causes SnoN and Ski protein degradation via proteasome with the participation of phosphorylated R-Smad proteins. Intriguingly, the antibiotics anisomycin (ANS) and puromycin (PURO) are also able to downregulate Ski and SnoN proteins via proteasome. METHODS We explored the effects of ANS and PURO on SnoN protein downregulation when the activity of TGF-β signaling was inhibited by using different pharmacological and non-pharmacological approaches, either by using specific TβRI inhibitors, overexpressing the inhibitory Smad7 protein, or knocking-down TβRI receptor or Smad2 by specific shRNAs. The outcome of SnoN and Ski downregulation induced by ANS or PURO on TGF-β signaling was also studied. RESULTS SnoN protein downregulation induced by ANS and PURO did not involve the induction of R-Smad phosphorylation but it was abrogated after TGF-β signaling inhibition; this effect occurred in a cell type-specific manner and independently of protein synthesis inhibition or any other ribotoxic effect. Intriguingly, antibiotics seem to require components of the TGF-β/Smad pathway to downregulate SnoN. In addition, SnoN protein downregulation induced by antibiotics favored gene transcription induced by TGF-β signaling. CONCLUSIONS ANS and PURO require TGF-β/Smad pathway to induce SnoN and Ski protein downregulation independently of inducing R-Smad2 phosphorylation, which facilitates TGF-β signaling. GENERAL SIGNIFICANCE Antibiotic analogs lacking ribotoxic effects are useful as pharmacological tools to study TGF-β signaling by controlling Ski and SnoN protein levels.
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Affiliation(s)
- Jacqueline Hernández-Damián
- Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., 04510 Mexico
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19
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Ski protein levels increase during in vitro progression of HPV16-immortalized human keratinocytes and in cervical cancer. Virology 2013; 444:100-8. [PMID: 23809940 DOI: 10.1016/j.virol.2013.05.039] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 05/23/2013] [Accepted: 05/30/2013] [Indexed: 01/23/2023]
Abstract
We compared the levels of the Ski oncoprotein, an inhibitor of transforming growth factor-beta (TGF-β) signaling, in normal human keratinocytes (HKc), HPV16 immortalized HKc (HKc/HPV16), and differentiation resistant HKc/HPV16 (HKc/DR) in the absence and presence of TGF-β. Steady-state Ski protein levels increased in HKc/HPV16 and even further in HKc/DR, compared to HKc. TGF-β treatment of HKc, HKc/HPV16, and HKc/DR dramatically decreased Ski. TGF-β-induced Ski degradation was delayed in HKc/DR. Ski and phospho-Ski protein levels are cell cycle dependent with maximal Ski expression and localization to centrosomes and mitotic spindles during G2/M. ShRNA knock down of Ski in HKc/DR inhibited cell proliferation. More intense nuclear and cytoplasmic Ski staining and altered Ski localization were found in cervical cancer samples compared to adjacent normal tissue in a cervical cancer tissue array. Overall, these studies demonstrate altered Ski protein levels, degradation and localization in HPV16-transformed human keratinocytes and in cervical cancer.
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20
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Li J, Li P, Zhang Y, Li GB, Zhou YG, Yang K, Dai SS. c-Ski inhibits the proliferation of vascular smooth muscle cells via suppressing Smad3 signaling but stimulating p38 pathway. Cell Signal 2012; 25:159-67. [PMID: 22986000 DOI: 10.1016/j.cellsig.2012.09.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 08/17/2012] [Accepted: 09/01/2012] [Indexed: 10/27/2022]
Abstract
Proliferation of vascular smooth muscle cells (VSMCs) plays key roles in the progression of intimal hyperplasia, but the molecular mechanisms that trigger VSMC proliferation after vascular injury remain unclear. c-Ski, a co-repressor of transforming growth factor β (TGF-β)/Smad signaling, was detected to express in VSMC of rat artery. During the course of arterial VSMC proliferation induced by balloon injury in rat, the endogenous protein expressions of c-Ski decreased markedly in a time-dependent manner. In vivo c-Ski gene delivery was found to significantly suppress balloon injury-induced VSMC proliferation and neointima formation. Further investigation in A10 rat aortic smooth muscle cells demonstrated that overexpression of c-Ski gene inhibited TGF-β1 (1 ng/ml)-induced A10 cell proliferation while knockdown of c-Ski by RNAi enhanced the stimulatory effect of TGF-β1 on A10 cell growth. Western blot for signaling detection showed that suppression of Smad3 phosphorylation while stimulating p38 signaling associated with upregulation of cyclin-dependent kinase inhibitors p21 and p27 was responsible for the inhibitory effect of c-Ski on TGF-β1-induced VSMC proliferation. These data suggest that the decrease of endogenous c-Ski expression is implicated in the progression of VSMC proliferation after arterial injury and c-Ski administration represents a promising role for treating intimal hyperplasia via inhibiting the proliferation of VSMC.
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Affiliation(s)
- Jun Li
- Department of Cardiothoracic Surgery, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
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21
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Xu P, Liu J, Derynck R. Post-translational regulation of TGF-β receptor and Smad signaling. FEBS Lett 2012; 586:1871-84. [PMID: 22617150 DOI: 10.1016/j.febslet.2012.05.010] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Revised: 05/06/2012] [Accepted: 05/07/2012] [Indexed: 01/17/2023]
Abstract
TGF-β family signaling through Smads is conceptually a simple and linear signaling pathway, driven by sequential phosphorylation, with type II receptors activating type I receptors, which in turn activate R-Smads. Nevertheless, TGF-β family proteins induce highly complex programs of gene expression responses that are extensively regulated, and depend on the physiological context of the cells. Regulation of TGF-β signaling occurs at multiple levels, including TGF-β activation, formation, activation and destruction of functional TGF-β receptor complexes, activation and degradation of Smads, and formation of Smad transcription complexes at regulatory gene sequences that cooperate with a diverse set of DNA binding transcription factors and coregulators. Here we discuss recent insights into the roles of post-translational modifications and molecular interaction networks in the functions of receptors and Smads in TGF-β signal responses. These layers of regulation demonstrate how a simple signaling system can be coopted to exert exquisitely regulated, complex responses.
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Affiliation(s)
- Pinglong Xu
- Department of Cell and Tissue Biology, Programs in Cell Biology and Developmental Biology, University of California, San Francisco, CA, USA
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22
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Ding B, Sun Y, Huang J. Overexpression of SKI oncoprotein leads to p53 degradation through regulation of MDM2 protein sumoylation. J Biol Chem 2012; 287:14621-30. [PMID: 22411991 DOI: 10.1074/jbc.m111.301523] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Protooncogene Ski was identified based on its ability to transform avian fibroblasts in vitro. In support of its oncogenic activity, SKI was found to be overexpressed in a variety of human cancers, although the exact molecular mechanism(s) responsible for its oncogenic activity is not fully understood. We found that SKI can negatively regulate p53 by decreasing its level through up-regulation of MDM2 activity, which is mediated by the ability of SKI to enhance sumoylation of MDM2. This stimulation of MDM2 sumoylation is accomplished through a direct interaction of SKI with SUMO-conjugating enzyme E2, Ubc9, resulting in enhanced thioester bond formation and mono-sumoylation of Ubc9. A mutant SKI defective in transformation fails to increase p53 ubiquitination and is unable to increase MDM2 levels and to increase mono-sumoylation of Ubc9, suggesting that the ability of SKI to enhance Ubc9 activity is essential for its transforming function. These results established a detailed molecular mechanism that underlies the ability of SKI to cause cellular transformation while unraveling a novel connection between sumoylation and tumorigenesis, providing potential new therapeutic targets for cancer.
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Affiliation(s)
- Boxiao Ding
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California 90095, USA
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23
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Duhoux FP, Ameye G, Lambot V, Herens C, Lambert F, Raynaud S, Wlodarska I, Michaux L, Roche-Lestienne C, Labis E, Taviaux S, Chapiro E, Nguyen-Khac F, Khac FN, Struski S, Dobbelstein S, Dastugue N, Lippert E, Speleman F, Van Roy N, De Weer A, Rack K, Talmant P, Richebourg S, Mugneret F, Tigaud I, Mozziconacci MJ, Laibe S, Nadal N, Terré C, Libouton JM, Decottignies A, Vikkula M, Poirel HA. Refinement of 1p36 alterations not involving PRDM16 in myeloid and lymphoid malignancies. PLoS One 2011; 6:e26311. [PMID: 22039459 PMCID: PMC3198844 DOI: 10.1371/journal.pone.0026311] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 09/23/2011] [Indexed: 01/06/2023] Open
Abstract
Fluorescence in situ hybridization was performed to characterize 81 cases of myeloid and lymphoid malignancies with cytogenetic 1p36 alterations not affecting the PRDM16 locus. In total, three subgroups were identified: balanced translocations (N = 27) and telomeric rearrangements (N = 15), both mainly observed in myeloid disorders; and unbalanced non-telomeric rearrangements (N = 39), mainly observed in lymphoid proliferations and frequently associated with a highly complex karyotype. The 1p36 rearrangement was isolated in 12 cases, mainly myeloid disorders. The breakpoints on 1p36 were more widely distributed than previously reported, but with identifiable rare breakpoint cluster regions, such as the TP73 locus. We also found novel partner loci on 1p36 for the known multi-partner genes HMGA2 and RUNX1. We precised the common terminal 1p36 deletion, which has been suggested to have an adverse prognosis, in B-cell lymphomas [follicular lymphomas and diffuse large B-cell lymphomas with t(14;18)(q32;q21) as well as follicular lymphomas without t(14;18)]. Intrachromosomal telomeric repetitive sequences were detected in at least half the cases of telomeric rearrangements. It is unclear how the latter rearrangements occurred and whether they represent oncogenic events or result from chromosomal instability during oncogenesis.
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Affiliation(s)
- Francois P Duhoux
- Center for Human Genetics, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium
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24
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Bonnon C, Atanasoski S. c-Ski in health and disease. Cell Tissue Res 2011; 347:51-64. [DOI: 10.1007/s00441-011-1180-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 04/15/2011] [Indexed: 01/28/2023]
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25
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Role of Smads in TGFβ signaling. Cell Tissue Res 2011; 347:21-36. [PMID: 21643690 DOI: 10.1007/s00441-011-1190-x] [Citation(s) in RCA: 264] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 05/10/2011] [Indexed: 02/07/2023]
Abstract
Transforming growth factor-β (TGFβ) is the prototype for a large family of pleiotropic factors that signal via heterotetrameric complexes of type I and type II serine/threonine kinase receptors. Important intracellular mediators of TGFβ signaling are members of the Smad family. Smad2 and 3 are activated by C-terminal receptor-mediated phosphorylation, whereafter they form complexes with Smad4 and are translocated to the nucleus where they, in cooperation with other transcription factors, co-activators and co-repressors, regulate the transcription of specific genes. Smads have key roles in exerting TGFβ-induced programs leading to cell growth arrest and epithelial-mesenchymal transition. The activity and stability of Smad molecules are carefully regulated by a plethora of post-translational modifications, including phosphorylation, ubiquitination, sumoylation, acetylation and poly(ADP)-ribosylation. The Smad function has been shown to be perturbed in certain diseases such as cancer.
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