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Miyazawa K, Itoh Y, Fu H, Miyazono K. Receptor-activated transcription factors and beyond: multiple modes of Smad2/3-dependent transmission of TGF-β signaling. J Biol Chem 2024; 300:107256. [PMID: 38569937 PMCID: PMC11063908 DOI: 10.1016/j.jbc.2024.107256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 02/28/2024] [Accepted: 03/05/2024] [Indexed: 04/05/2024] Open
Abstract
Transforming growth factor β (TGF-β) is a pleiotropic cytokine that is widely distributed throughout the body. Its receptor proteins, TGF-β type I and type II receptors, are also ubiquitously expressed. Therefore, the regulation of various signaling outputs in a context-dependent manner is a critical issue in this field. Smad proteins were originally identified as signal-activated transcription factors similar to signal transducer and activator of transcription proteins. Smads are activated by serine phosphorylation mediated by intrinsic receptor dual specificity kinases of the TGF-β family, indicating that Smads are receptor-restricted effector molecules downstream of ligands of the TGF-β family. Smad proteins have other functions in addition to transcriptional regulation, including post-transcriptional regulation of micro-RNA processing, pre-mRNA splicing, and m6A methylation. Recent technical advances have identified a novel landscape of Smad-dependent signal transduction, including regulation of mitochondrial function without involving regulation of gene expression. Therefore, Smad proteins are receptor-activated transcription factors and also act as intracellular signaling modulators with multiple modes of function. In this review, we discuss the role of Smad proteins as receptor-activated transcription factors and beyond. We also describe the functional differences between Smad2 and Smad3, two receptor-activated Smad proteins downstream of TGF-β, activin, myostatin, growth and differentiation factor (GDF) 11, and Nodal.
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Affiliation(s)
- Keiji Miyazawa
- Department of Biochemistry, Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.
| | - Yuka Itoh
- Department of Biochemistry, Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Hao Fu
- Department of Biochemistry, Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Kohei Miyazono
- Department of Applied Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Laboratory for Cancer Invasion and Metastasis, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
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Runa F, Ortiz-Soto G, de Barros NR, Kelber JA. Targeting SMAD-Dependent Signaling: Considerations in Epithelial and Mesenchymal Solid Tumors. Pharmaceuticals (Basel) 2024; 17:326. [PMID: 38543112 PMCID: PMC10975212 DOI: 10.3390/ph17030326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 02/19/2024] [Accepted: 02/23/2024] [Indexed: 04/01/2024] Open
Abstract
SMADs are the canonical intracellular effector proteins of the TGF-β (transforming growth factor-β). SMADs translocate from plasma membrane receptors to the nucleus regulated by many SMAD-interacting proteins through phosphorylation and other post-translational modifications that govern their nucleocytoplasmic shuttling and subsequent transcriptional activity. The signaling pathway of TGF-β/SMAD exhibits both tumor-suppressing and tumor-promoting phenotypes in epithelial-derived solid tumors. Collectively, the pleiotropic nature of TGF-β/SMAD signaling presents significant challenges for the development of effective cancer therapies. Here, we review preclinical studies that evaluate the efficacy of inhibitors targeting major SMAD-regulating and/or -interacting proteins, particularly enzymes that may play important roles in epithelial or mesenchymal compartments within solid tumors.
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Affiliation(s)
- Farhana Runa
- Department of Biology, California State University Northridge, Northridge, CA 91330, USA
| | | | | | - Jonathan A Kelber
- Department of Biology, California State University Northridge, Northridge, CA 91330, USA
- Department of Biology, Baylor University, Waco, TX 76706, USA
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Wang Y, Zhang K, Guo J, Yang S, Shi X, Pan J, Sun Z, Zou J, Li Y, Li Y, Fan T, Song W, Cheng F, Zeng C, Li J, Zhang T, Sun ZS. Loss-of-Function of p21-Activated Kinase 2 Links BMP Signaling to Neural Tube Patterning Defects. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2204018. [PMID: 36504449 PMCID: PMC9896034 DOI: 10.1002/advs.202204018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 11/02/2022] [Indexed: 06/17/2023]
Abstract
Closure of the neural tube represents a highly complex and coordinated process, the failure of which constitutes common birth defects. The serine/threonine kinase p21-activated kinase 2 (PAK2) is a critical regulator of cytoskeleton dynamics; however, its role in the neurulation and pathogenesis of neural tube defects (NTDs) remains unclear. Here, the results show that Pak2-/- mouse embryos fail to develop dorsolateral hinge points (DLHPs) and exhibit craniorachischisis, a severe phenotype of NTDs. Pak2 knockout activates BMP signaling that involves in vertebrate bone formation. Single-cell transcriptomes reveal abnormal differentiation trajectories and transcriptional events in Pak2-/- mouse embryos during neural tube development. Two nonsynonymous and one recurrent splice-site mutations in the PAK2 gene are identified in five human NTD fetuses, which exhibit attenuated PAK2 expression and upregulated BMP signaling in the brain. Mechanistically, PAK2 regulates Smad9 phosphorylation to inhibit BMP signaling and ultimately induce DLHP formation. Depletion of pak2a in zebrafish induces defects in the neural tube, which are partially rescued by the overexpression of wild-type, but not mutant PAK2. The findings demonstrate the conserved role of PAK2 in neurulation in multiple vertebrate species, highlighting the molecular pathogenesis of PAK2 mutations in NTDs.
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Affiliation(s)
- Yan Wang
- Beijing Institutes of Life ScienceChinese Academy of SciencesBeijing100101China
- CAS Center for Excellence in Biotic InteractionsUniversity of Chinese Academy of SciencesBeijing100049China
| | - Kaifan Zhang
- Institute of Genomic MedicineWenzhou Medical UniversityWenzhouZhejiang325000China
| | - Jin Guo
- Beijing Municipal Key Laboratory of Child Development and NutriomicsCapital Institute of PediatricsBeijing100020China
| | - Shuyan Yang
- Beijing Municipal Key Laboratory of Child Development and NutriomicsCapital Institute of PediatricsBeijing100020China
| | - Xiaohui Shi
- Beijing Institutes of Life ScienceChinese Academy of SciencesBeijing100101China
- CAS Center for Excellence in Biotic InteractionsUniversity of Chinese Academy of SciencesBeijing100049China
| | - Jinrong Pan
- Beijing Institutes of Life ScienceChinese Academy of SciencesBeijing100101China
- CAS Center for Excellence in Biotic InteractionsUniversity of Chinese Academy of SciencesBeijing100049China
| | - Zheng Sun
- Beijing Institutes of Life ScienceChinese Academy of SciencesBeijing100101China
- CAS Center for Excellence in Biotic InteractionsUniversity of Chinese Academy of SciencesBeijing100049China
| | - Jizhen Zou
- Beijing Municipal Key Laboratory of Child Development and NutriomicsCapital Institute of PediatricsBeijing100020China
| | - Yi Li
- Institute of Genomic MedicineWenzhou Medical UniversityWenzhouZhejiang325000China
| | - Yuanyuan Li
- Beijing Institutes of Life ScienceChinese Academy of SciencesBeijing100101China
- CAS Center for Excellence in Biotic InteractionsUniversity of Chinese Academy of SciencesBeijing100049China
| | - Tianda Fan
- Institute of Genomic MedicineWenzhou Medical UniversityWenzhouZhejiang325000China
| | - Wei Song
- Beijing Institutes of Life ScienceChinese Academy of SciencesBeijing100101China
- CAS Center for Excellence in Biotic InteractionsUniversity of Chinese Academy of SciencesBeijing100049China
| | - Fang Cheng
- Institute of Genomic MedicineWenzhou Medical UniversityWenzhouZhejiang325000China
| | - Cheng Zeng
- Beijing Institutes of Life ScienceChinese Academy of SciencesBeijing100101China
- CAS Center for Excellence in Biotic InteractionsUniversity of Chinese Academy of SciencesBeijing100049China
| | - Jinchen Li
- Bioinformatics Center & National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangshaHunan410078China
| | - Ting Zhang
- Beijing Municipal Key Laboratory of Child Development and NutriomicsCapital Institute of PediatricsBeijing100020China
| | - Zhong Sheng Sun
- Beijing Institutes of Life ScienceChinese Academy of SciencesBeijing100101China
- CAS Center for Excellence in Biotic InteractionsUniversity of Chinese Academy of SciencesBeijing100049China
- Institute of Genomic MedicineWenzhou Medical UniversityWenzhouZhejiang325000China
- State Key Laboratory of Integrated Management of Pest Insects and RodentsChinese Academy of SciencesBeijing100101China
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Wang K, Wen D, Xu X, Zhao R, Jiang F, Yuan S, Zhang Y, Gao Y, Li Q. Extracellular matrix stiffness-The central cue for skin fibrosis. Front Mol Biosci 2023; 10:1132353. [PMID: 36968277 PMCID: PMC10031116 DOI: 10.3389/fmolb.2023.1132353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 02/20/2023] [Indexed: 03/29/2023] Open
Abstract
Skin fibrosis is a physiopathological process featuring the excessive deposition of extracellular matrix (ECM), which is the main architecture that provides structural support and constitutes the microenvironment for various cellular behaviors. Recently, increasing interest has been drawn to the relationship between the mechanical properties of the ECM and the initiation and modulation of skin fibrosis, with the engagement of a complex network of signaling pathways, the activation of mechanosensitive proteins, and changes in immunoregulation and metabolism. Simultaneous with the progression of skin fibrosis, the stiffness of ECM increases, which in turn perturbs mechanical and humoral homeostasis to drive cell fate toward an outcome that maintains and enhances the fibrosis process, thus forming a pro-fibrotic "positive feedback loop". In this review, we highlighted the central role of the ECM and its dynamic changes at both the molecular and cellular levels in skin fibrosis. We paid special attention to signaling pathways regulated by mechanical cues in ECM remodeling. We also systematically summarized antifibrotic interventions targeting the ECM, hopefully enlightening new strategies for fibrotic diseases.
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Affiliation(s)
- Kang Wang
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Burn and Plastic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Dongsheng Wen
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xuewen Xu
- Department of Burn and Plastic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Rui Zhao
- West China School of Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Feipeng Jiang
- West China School of Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Shengqin Yuan
- School of Public Administration, Sichuan University, Chengdu, Sichuan, China
| | - Yifan Zhang
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- *Correspondence: Yifan Zhang, ; Ya Gao, ; Qingfeng Li,
| | - Ya Gao
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- *Correspondence: Yifan Zhang, ; Ya Gao, ; Qingfeng Li,
| | - Qingfeng Li
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- *Correspondence: Yifan Zhang, ; Ya Gao, ; Qingfeng Li,
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Kathania M, Kumar R, Lenou ET, Basrur V, Theiss AL, Chernoff J, Venuprasad K. Pak2-mediated phosphorylation promotes RORγt ubiquitination and inhibits colonic inflammation. Cell Rep 2022; 40:111345. [PMID: 36103814 PMCID: PMC9510046 DOI: 10.1016/j.celrep.2022.111345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 07/09/2022] [Accepted: 08/22/2022] [Indexed: 11/20/2022] Open
Abstract
Dysregulated interleukin-17 (IL-17) expression and its downstream signaling is strongly linked to inflammatory bowel diseases (IBDs). However, the molecular mechanisms by which the function of RORγt, the transcription factor of IL-17, is regulated remains elusive. By a mass spectrometry-based approach, we identify that Pak2, a serine (S)/threonine (T) kinase, directly associates with RORγt. Pak2 recognizes a conserved KRLS motif within RORγt and phosphorylates the S-316 within this motif. Genetic deletion of Pak2 in Th17 cells reduces RORγt phosphorylation, increases IL-17 expression, and induces severe colitis upon adoptive transfer to Rag1−/− mice. Similarly, reconstitution of RORγt-S316A mutant in Rorc−/− Th17 cells enhances IL-17 expression and colitis severity. Mechanistically, we demonstrate that Pak2-mediated phosphorylation causes a conformational change resulting in exposure of the ubiquitin ligase Itch interacting PPLY motif and degradation of RORγt. Thus, we have uncovered a mechanism by which the activity of RORγt is regulated that can be exploited therapeutically. Kathania et al. show that Pak2, a Ser/Thr kinase, associates with RORγt and phosphorylates Ser-316 of RORγt. Deletion of Pak2 in Th17 cells enhances IL-17 expression and colitis severity. Pak2-mediated phosphorylation causes a conformational change resulting in increased ubiquitination of RORγt by the E3 ubiquitin ligase Itch.
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Affiliation(s)
- Mahesh Kathania
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX 75390, USA; Department of Immunology, UT Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ritesh Kumar
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX 75390, USA; Department of Immunology, UT Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Elviche Taskem Lenou
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX 75390, USA; Department of Immunology, UT Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Venkatesha Basrur
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Arianne L Theiss
- University of Colorado, School of Medicine, Division of Gastroenterology and Hepatology, Anschutz Medical Campus, Aurora, CO, USA
| | - Jonathan Chernoff
- Cancer Signaling and Epigenetics Program, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - K Venuprasad
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX 75390, USA; Department of Immunology, UT Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, TX 75390, USA.
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Nozaki M, Nishizuka M. Repression of RhoJ expression promotes TGF-β-mediated EMT in human non-small-cell lung cancer A549cells. Biochem Biophys Res Commun 2021; 566:94-100. [PMID: 34119829 DOI: 10.1016/j.bbrc.2021.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 06/02/2021] [Indexed: 12/13/2022]
Abstract
Non-small-cell lung cancer (NSCLC) accounts for most cancer-related deaths because of its strong metastatic ability. It is important to understand NSCLC's molecular mechanisms of metastasis. RhoJ, a protein that belongs to the Rho family of small GTPases, regulates endothelial motility, angiogenesis, and adipogenesis. Recently, bioinformatics analysis showed that NSCLC patients with lower RhoJ expression had a worse survival outcome than those with high RhoJ expression. However, little is known about RhoJ's role in NSCLC. In the present study, we demonstrated that RhoJ knockdown accelerated TGF-βmediated epithelial-to-mesenchymal transition (EMT), an important cancer metastasis process, in A549 and PC-9 cells. Furthermore, using Matrigel-coated transwell chambers, we showed that RhoJ knockdown enhanced the invasion capacity of A549 cells that had undergone EMT. Also, reduced RhoJ expression increased Smad3 phosphorylation and Snail expression during the EMT process. Our results provide the first evidence of a potential novel role for RhoJ in the inhibition of EMT via modulation of the TGF-β-Smad signaling pathway, and shed new light on the mechanisms underlying EMT in NSCLC.
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Affiliation(s)
- Misa Nozaki
- Graduate School of Sustainable Community Studies, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan
| | - Makoto Nishizuka
- Graduate School of Sustainable Community Studies, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan; Department of Applied Biology and Food Sciences, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori, 036-8561, Japan.
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7
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Zhang K, Zhang M, Luo Z, Wen Z, Yan X. The dichotomous role of TGF-β in controlling liver cancer cell survival and proliferation. J Genet Genomics 2020; 47:497-512. [PMID: 33339765 DOI: 10.1016/j.jgg.2020.09.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 09/14/2020] [Accepted: 09/29/2020] [Indexed: 12/24/2022]
Abstract
Hepatocellular carcinoma (HCC) is the major form of primary liver cancer and one of the most prevalent and life-threatening malignancies globally. One of the hallmarks in HCC is the sustained cell survival and proliferative signals, which are determined by the balance between oncogenes and tumor suppressors. Transforming growth factor beta (TGF-β) is an effective growth inhibitor of epithelial cells including hepatocytes, through induction of cell cycle arrest, apoptosis, cellular senescence, or autophagy. The antitumorigenic effects of TGF-β are bypassed during liver tumorigenesis via multiple mechanisms. Furthermore, along with malignant progression, TGF-β switches to promote cancer cell survival and proliferation. This dichotomous nature of TGF-β is one of the barriers to therapeutic targeting in liver cancer. Thereafter, understanding the underlying molecular mechanisms is a prerequisite for discovering novel antitumor drugs that may specifically disable the growth-promoting branch of TGF-β signaling or restore its tumor-suppressive arm. This review summarizes how TGF-β inhibits or promotes liver cancer cell survival and proliferation, highlighting the functional switch mechanisms during the process.
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Affiliation(s)
- Kegui Zhang
- School of Biological Engineering, Huainan Normal University, Huainan, 232001, China
| | - Meiping Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang, 330006, China
| | - Zhijun Luo
- School of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - Zhili Wen
- Department of Gastroenterology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, China.
| | - Xiaohua Yan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang, 330006, China; Institute of Biomedical Sciences, Nanchang University Medical College, Nanchang, 330031, China.
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Li Y, Tu S, Zeng Y, Zhang C, Deng T, Luo W, Lian L, Chen L, Xiong X, Yan X. KLF2 inhibits TGF-β-mediated cancer cell motility in hepatocellular carcinoma. Acta Biochim Biophys Sin (Shanghai) 2020; 52:485-494. [PMID: 32318691 DOI: 10.1093/abbs/gmaa024] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 10/17/2019] [Accepted: 12/26/2019] [Indexed: 12/16/2022] Open
Abstract
Feedback regulation plays a pivotal role in determining the intensity and duration of TGF-β signaling and subsequently affecting the pathophysiological roles of TGF-β, including those in liver malignancy. KLF2, a member of the Krüppel-like factor (KLF) family transcription factors, has been implicated in impeding hepatocellular carcinoma (HCC) development. However, the underlying molecular mechanisms are not fully understood. In the present study, we found that TGF-β stimulates the expression of KLF2 gene in several HCC cell lines. KLF2 protein is able to inhibit TGF-β/Smad signaling in HCC cells as assessed by luciferase reporter assay. Further studies indicated that KLF2 inhibits the transcriptional activity of Smad2/3 and Smad4 and ameliorates TGF-β-induced target gene expression, therefore creating a novel negative feedback loop in TGF-β signaling. Functionally, stably expression of KLF2 in HCCLM3 cells attenuated TGF-β-induced cancer cell motility in wound-healing and transwell assays by interfering with TGF-β-mediated upregulation of MMP2. Together, our results revealed that KLF2 protein has a tumor-suppressive function in HCC through a negative feedback loop over TGF-β signaling.
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Affiliation(s)
- Yining Li
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - Shuo Tu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - Yi Zeng
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - Cheng Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - Tian Deng
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - Weicheng Luo
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - Lingyan Lian
- The Second Affiliated Hospital of Nanchang University, Nanchang 330006, China
| | - Ling Chen
- The Health Department of the First Affiliated Hospital of Nanchang University, Nanchang 330006, China
| | - Xiangyang Xiong
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - Xiaohua Yan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
- Institute of Biomedical Sciences, Nanchang University, Nanchang 330006, China
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Tzavlaki K, Moustakas A. TGF-β Signaling. Biomolecules 2020; 10:biom10030487. [PMID: 32210029 PMCID: PMC7175140 DOI: 10.3390/biom10030487] [Citation(s) in RCA: 403] [Impact Index Per Article: 100.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/19/2020] [Accepted: 03/20/2020] [Indexed: 02/06/2023] Open
Abstract
Transforming growth factor-β (TGF-β) represents an evolutionarily conserved family of secreted polypeptide factors that regulate many aspects of physiological embryogenesis and adult tissue homeostasis. The TGF-β family members are also involved in pathophysiological mechanisms that underlie many diseases. Although the family comprises many factors, which exhibit cell type-specific and developmental stage-dependent biological actions, they all signal via conserved signaling pathways. The signaling mechanisms of the TGF-β family are controlled at the extracellular level, where ligand secretion, deposition to the extracellular matrix and activation prior to signaling play important roles. At the plasma membrane level, TGF-βs associate with receptor kinases that mediate phosphorylation-dependent signaling to downstream mediators, mainly the SMAD proteins, and mediate oligomerization-dependent signaling to ubiquitin ligases and intracellular protein kinases. The interplay between SMADs and other signaling proteins mediate regulatory signals that control expression of target genes, RNA processing at multiple levels, mRNA translation and nuclear or cytoplasmic protein regulation. This article emphasizes signaling mechanisms and the importance of biochemical control in executing biological functions by the prototype member of the family, TGF-β.
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Contextual Regulation of TGF-β Signaling in Liver Cancer. Cells 2019; 8:cells8101235. [PMID: 31614569 PMCID: PMC6829617 DOI: 10.3390/cells8101235] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/09/2019] [Accepted: 10/10/2019] [Indexed: 02/06/2023] Open
Abstract
Primary liver cancer is one of the leading causes for cancer-related death worldwide. Transforming growth factor beta (TGF-β) is a pleiotropic cytokine that signals through membrane receptors and intracellular Smad proteins, which enter the nucleus upon receptor activation and act as transcription factors. TGF-β inhibits liver tumorigenesis in the early stage by inducing cytostasis and apoptosis, but promotes malignant progression in more advanced stages by enhancing cancer cell survival, EMT, migration, invasion and finally metastasis. Understanding the molecular mechanisms underpinning the multi-faceted roles of TGF-β in liver cancer has become a persistent pursuit during the last two decades. Contextual regulation fine-tunes the robustness, duration and plasticity of TGF-β signaling, yielding versatile albeit specific responses. This involves multiple feedback and feed-forward regulatory loops and also the interplay between Smad signaling and non-Smad pathways. This review summarizes the known regulatory mechanisms of TGF-β signaling in liver cancer, and how they channel, skew and even switch the actions of TGF-β during cancer progression.
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MicroRNA-455-3p promotes TGF-β signaling and inhibits osteoarthritis development by directly targeting PAK2. Exp Mol Med 2019; 51:1-13. [PMID: 31586040 PMCID: PMC6802609 DOI: 10.1038/s12276-019-0322-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 08/13/2019] [Accepted: 08/22/2019] [Indexed: 12/17/2022] Open
Abstract
MicroRNAs (miRNAs, miR) play a key role in the pathogenesis of osteoarthritis (OA). Few studies have examined the regulatory role of P21-activated kinases (PAKs), a family of serine/threonine kinases, in OA. The aim of this study was to determine whether miR-455-3p can regulate cartilage degeneration in OA by targeting PAK2. MiR-455-3p knockout mice showed significant degeneration of the knee cartilage. MiR-455-3p expression increased and PAK2 expression decreased in the late stage of human adipose-derived stem cell (hADSC) chondrogenesis and in chondrocytes affected by OA. Furthermore, in both miR-455-3p-overexpressing chondrocytes and PAK2-suppressing chondrocytes, cartilage-specific genes were upregulated, and hypertrophy-related genes were downregulated. A luciferase reporter assay confirmed that miR-455-3p regulates PAK2 expression by directly targeting the 3′-untranslated regions (3′UTRs) of PAK2 mRNA. IPA-3, a PAK inhibitor, inhibited cartilage degeneration due to OA. Moreover, suppressing PAK2 promoted R-Smad activation in the TGF/Smad signaling pathway in chondrocytes. Altogether, our results suggest that miR-455-3p promotes TGF-β/Smad signaling in chondrocytes and inhibits cartilage degeneration by directly suppressing PAK2. These results thus indicate that miR-455-3p and PAK2 are novel potential therapeutic agents and targets, respectively, for the treatment of OA. Functional insights into a short RNA strand that prevents cartilage degeneration could lead to new therapeutic strategies for treating osteoarthritis. The microRNA miR-455-3p regulates genes in tissues throughout the body, but Weiming Liao and Zhiqi Zhang of the First Affiliated Hospital of Sun Yat-sen University in Guangzhou, China have observed that it appears to play a particularly prominent role in cartilage-producing chondrocyte cells. Liao, Zhang and colleagues have now explored this mechanism in detail, and determined that miR-455-3p selectively blocks the effects of a protein called PAK2 in chondrocytes. PAK2 normally inhibits an important signaling pathway underlying cartilage generation, and such inhibition has previously been observed in MDCK epithelial cells. The authors conclude that this microRNA or other drugs that replicate its PAK2-inhibiting effects could prevent or slow the joint damage associated with this degenerative disorder.
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Geng N, Li Y, Zhang W, Wang F, Wang X, Jin Z, Xing Y, Li D, Zhang H, Li Y, Li X, Cheng M, Jin F, Li F. A PAK5-DNPEP-USP4 axis dictates breast cancer growth and metastasis. Int J Cancer 2019; 146:1139-1151. [PMID: 31219614 DOI: 10.1002/ijc.32523] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 05/20/2019] [Accepted: 06/13/2019] [Indexed: 12/30/2022]
Abstract
Although clinically associated with the progression of multiple cancers, the biological function of p21-activated kinase 5 (PAK5) in breast cancer remains largely unknown. Here, we reveal that the PAK5-aspartyl aminopeptidase (DNPEP)-ubiquitin-specific protease 4 (USP4) axis is involved in breast cancer progression. We show that PAK5 interacts with and phosphorylates DNPEP at serine 119. Functionally, we demonstrate that DNPEP overexpression suppresses breast cancer cell proliferation and invasion and restricts breast cancer growth and metastasis in mice. Furthermore, we identify USP4 as a downstream target of the PAK5-DNPEP pathway; DNPEP mediates USP4 downregulation. Importantly, we verify that DNPEP expression is frequently downregulated in breast cancer tissues and is negatively correlated with PAK5 and USP4 expression. PAK5 decreases DNPEP abundance via the ubiquitin-proteasome pathway. Consistently, analyses of clinical breast cancer specimens revealed significantly increased PAK5 and USP4 levels and an association between higher PAK5 and USP4 expression and worse breast cancer patient survival. These findings suggest a pivotal role for PAK5-elicited signaling in breast cancer progression.
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Affiliation(s)
- Nanxi Geng
- Department of Cell Biology, Key Laboratory of Cell Biology of Ministry of Public Health, and Key Laboratory of Medical Cell Biology of Ministry of Education, China Medical University, Shenyang, Liaoning, China
| | - Yang Li
- Department of Cell Biology, Key Laboratory of Cell Biology of Ministry of Public Health, and Key Laboratory of Medical Cell Biology of Ministry of Education, China Medical University, Shenyang, Liaoning, China
| | - Wenyu Zhang
- Department of Cell Biology, Key Laboratory of Cell Biology of Ministry of Public Health, and Key Laboratory of Medical Cell Biology of Ministry of Education, China Medical University, Shenyang, Liaoning, China
| | - Fei Wang
- Department of Cell Biology, Key Laboratory of Cell Biology of Ministry of Public Health, and Key Laboratory of Medical Cell Biology of Ministry of Education, China Medical University, Shenyang, Liaoning, China
| | - Xu Wang
- Department of Breast Surgery, Department of Surgical Oncology, Research Unit of General Surgery, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China
| | - Zining Jin
- Department of Breast Surgery, Department of Surgical Oncology, Research Unit of General Surgery, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China
| | - Yao Xing
- Department of Cell Biology, Key Laboratory of Cell Biology of Ministry of Public Health, and Key Laboratory of Medical Cell Biology of Ministry of Education, China Medical University, Shenyang, Liaoning, China
| | - Danni Li
- Department of Medical Oncology, The First Affiliated Hospital of China Medical University, Shenyang, China
| | - Hongyan Zhang
- Department of Cell Biology, Key Laboratory of Cell Biology of Ministry of Public Health, and Key Laboratory of Medical Cell Biology of Ministry of Education, China Medical University, Shenyang, Liaoning, China
| | - Yanshu Li
- Department of Cell Biology, Key Laboratory of Cell Biology of Ministry of Public Health, and Key Laboratory of Medical Cell Biology of Ministry of Education, China Medical University, Shenyang, Liaoning, China
| | - Xiaodong Li
- Department of Cell Biology, Key Laboratory of Cell Biology of Ministry of Public Health, and Key Laboratory of Medical Cell Biology of Ministry of Education, China Medical University, Shenyang, Liaoning, China
| | - Maosheng Cheng
- Key Laboratory of Structure-Based Drug Design and Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang, Liaoning, China
| | - Feng Jin
- Department of Breast Surgery, Department of Surgical Oncology, Research Unit of General Surgery, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China
| | - Feng Li
- Department of Cell Biology, Key Laboratory of Cell Biology of Ministry of Public Health, and Key Laboratory of Medical Cell Biology of Ministry of Education, China Medical University, Shenyang, Liaoning, China
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13
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Wang K, Li H, Sun R, Liu C, Luo Y, Fu S, Ying Y. Emerging roles of transforming growth factor β signaling in wet age-related macular degeneration. Acta Biochim Biophys Sin (Shanghai) 2019; 51:1-8. [PMID: 30496406 DOI: 10.1093/abbs/gmy145] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 10/31/2018] [Indexed: 12/25/2022] Open
Abstract
Age-related macular degeneration (AMD) is one of the major causes of irreversible blindness among aging populations in developed countries and can be classified as dry or wet according to its progression. Wet AMD, which is characterized by angiogenesis on the choroidal membrane, is uncommonly seen but more severe. Controlling or completely inhibiting the factors that contribute to the progression of events that lead to angiogenesis may be an effective strategy for treating wet AMD. Emerging evidence has shown that transforming growth factor-β (TGF-β) signaling plays a significant role in the progression of wet AMD. In this review, we described the roles of and changes in TGF-β signaling in the development of AMD and discussed the mechanisms of the TGF-β superfamily in choroidal neovascularization (CNV) and wet AMD, including the modulation of angiogenesis-related factors, inflammation, vascular fibrosis, and immune responses, as well as cross-talk with other signaling pathways. These remarkable findings indicate that TGF-β signaling is a potential target for wet AMD treatment.
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Affiliation(s)
- Kai Wang
- Jiangxi Province Key Laboratory of Tumor Pathogens and Molecular Pathology and Department of Pathology, Schools of Basic Medical Sciences and Pharmaceutical Sciences, Nanchang University Medical College, Nanchang, China
- Nanchang Joint Program, Queen Mary University of London, London, UK
| | - Haoran Li
- Jiangxi Province Key Laboratory of Tumor Pathogens and Molecular Pathology and Department of Pathology, Schools of Basic Medical Sciences and Pharmaceutical Sciences, Nanchang University Medical College, Nanchang, China
- Nanchang Joint Program, Queen Mary University of London, London, UK
| | - Ruipu Sun
- Jiangxi Province Key Laboratory of Tumor Pathogens and Molecular Pathology and Department of Pathology, Schools of Basic Medical Sciences and Pharmaceutical Sciences, Nanchang University Medical College, Nanchang, China
- Nanchang Joint Program, Queen Mary University of London, London, UK
| | - Chaxian Liu
- Jiangxi Province Key Laboratory of Tumor Pathogens and Molecular Pathology and Department of Pathology, Schools of Basic Medical Sciences and Pharmaceutical Sciences, Nanchang University Medical College, Nanchang, China
- The Second Clinical Department, School of Medicine, Nanchang University, Nanchang, China
| | - Yunfei Luo
- Jiangxi Province Key Laboratory of Tumor Pathogens and Molecular Pathology and Department of Pathology, Schools of Basic Medical Sciences and Pharmaceutical Sciences, Nanchang University Medical College, Nanchang, China
- Department of Pathophysiology, School of Medicine, Nanchang University, Nanchang, China
| | - Shuhua Fu
- Department of Ophthalmology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Ying Ying
- Jiangxi Province Key Laboratory of Tumor Pathogens and Molecular Pathology and Department of Pathology, Schools of Basic Medical Sciences and Pharmaceutical Sciences, Nanchang University Medical College, Nanchang, China
- Department of Pathophysiology, School of Medicine, Nanchang University, Nanchang, China
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14
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Xiong X, Tu S, Wang J, Luo S, Yan X. CXXC5: A novel regulator and coordinator of TGF-β, BMP and Wnt signaling. J Cell Mol Med 2018; 23:740-749. [PMID: 30479059 PMCID: PMC6349197 DOI: 10.1111/jcmm.14046] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 10/23/2018] [Indexed: 12/18/2022] Open
Abstract
CXXC5 is a member of the CXXC-type zinc-finger protein family. Proteins in this family play a pivotal role in epigenetic regulation by binding to unmethylated CpG islands in gene promoters through their characteristic CXXC domain. CXXC5 is a short protein (322 amino acids in length) that does not have any catalytic domain, but is able to bind to DNA and act as a transcription factor and epigenetic factor through protein-protein interactions. Intriguingly, increasing evidence indicates that expression of the CXXC5 gene is controlled by multiple signaling pathways and a variety of transcription factors, positioning CXXC5 as an important signal integrator. In addition, CXXC5 is capable of regulating various signal transduction processes, including the TGF-β, Wnt and ATM-p53 pathways, thereby acting as a novel and crucial signaling coordinator. CXXC5 plays an important role in embryonic development and adult tissue homeostasis by regulating cell proliferation, differentiation and apoptosis. In keeping with these functions, aberrant expression or altered activity of CXXC5 has been shown to be involved in several human diseases including tumourigenesis. This review summarizes the current understanding of CXXC5 as a transcription factor and signaling regulator and coordinator.
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Affiliation(s)
- Xiangyang Xiong
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang, China
| | - Shuo Tu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang, China
| | - Jianbin Wang
- School of Basic Medical Sciences, Nanchang University, Nanchang, China
| | - Shiwen Luo
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xiaohua Yan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang, China
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15
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Yan X, Xiong X, Chen YG. Feedback regulation of TGF-β signaling. Acta Biochim Biophys Sin (Shanghai) 2018; 50:37-50. [PMID: 29228156 DOI: 10.1093/abbs/gmx129] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Indexed: 12/20/2022] Open
Abstract
Transforming growth factor beta (TGF-β) is a multi-functional polypeptide that plays a critical role in regulating a broad range of cellular functions and physiological processes. Signaling is initiated when TGF-β ligands bind to two types of cell membrane receptors with intrinsic Ser/Thr kinase activity and transmitted by the intracellular Smad proteins, which act as transcription factors to regulate gene expression in the nucleus. Although it is relatively simple and straight-forward, this TGF-β/Smad pathway is regulated by various feedback loops at different levels, including the ligand, the receptor, Smads and transcription, and is thus fine-tuned in terms of signaling robustness, duration, specificity, and plasticity. The precise control gives rise to versatile and context-dependent pathophysiological functions. In this review, we firstly give an overview of TGF-β signaling, and then discuss how each step of TGF-β signaling is finely controlled by distinct modes of feedback mechanisms, involving both protein regulators and miRNAs.
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Affiliation(s)
- Xiaohua Yan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - Xiangyang Xiong
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang 330006, China
| | - 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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16
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Yan X, Wu J, Jiang Q, Cheng H, Han JDJ, Chen YG. CXXC5 suppresses hepatocellular carcinoma by promoting TGF-β-induced cell cycle arrest and apoptosis. J Mol Cell Biol 2017; 10:48-59. [DOI: 10.1093/jmcb/mjx042] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Accepted: 09/18/2017] [Indexed: 12/18/2022] Open
Affiliation(s)
- Xiaohua Yan
- The State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang, China
| | - Jingyi Wu
- The State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Quanlong Jiang
- Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Hao Cheng
- Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jing-Dong J Han
- Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Ye-Guang Chen
- The State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
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17
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Xu P, Lin X, Feng XH. Posttranslational Regulation of Smads. Cold Spring Harb Perspect Biol 2016; 8:cshperspect.a022087. [PMID: 27908935 DOI: 10.1101/cshperspect.a022087] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Transforming growth factor β (TGF-β) family signaling dictates highly complex programs of gene expression responses, which are extensively regulated at multiple levels and vary depending on the physiological context. The formation, activation, and destruction of two major functional complexes in the TGF-β signaling pathway (i.e., the TGF-β receptor complexes and the Smad complexes that act as central mediators of TGF-β signaling) are direct targets for posttranslational regulation. Dysfunction of these complexes often leads or contributes to pathogenesis in cancer and fibrosis and in cardiovascular, and autoimmune diseases. Here we discuss recent insights into the roles of posttranslational modifications in the functions of the receptor-activated Smads in the common Smad4 and inhibitory Smads, and in the control of the physiological responses to TGF-β. It is now evident that these modifications act as decisive factors in defining the intensity and versatility of TGF-β responsiveness. Thus, the characterization of posttranslational modifications of Smads not only sheds light on how TGF-β controls physiological and pathological processes but may also guide us to manipulate the TGF-β responses for therapeutic benefits.
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Affiliation(s)
- Pinglong Xu
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xia Lin
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030
| | - Xin-Hua Feng
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058, China.,Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030.,Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, Texas 77030
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18
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Yan X, Liao H, Cheng M, Shi X, Lin X, Feng XH, Chen YG. Smad7 Protein Interacts with Receptor-regulated Smads (R-Smads) to Inhibit Transforming Growth Factor-β (TGF-β)/Smad Signaling. J Biol Chem 2015; 291:382-92. [PMID: 26555259 DOI: 10.1074/jbc.m115.694281] [Citation(s) in RCA: 138] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Indexed: 12/20/2022] Open
Abstract
TGF-β is a pleiotropic cytokine that regulates a wide range of cellular actions and pathophysiological processes. TGF-β signaling is spatiotemporally fine-tuned. As a key negative regulator of TGF-β signaling, Smad7 exerts its inhibitory effects by blocking receptor activity, inducing receptor degradation or interfering with Smad-DNA binding. However, the functions and the molecular mechanisms underlying the actions of Smad7 in TGF-β signaling are still not fully understood. In this study we report a novel mechanism whereby Smad7 antagonizes TGF-β signaling at the Smad level. Smad7 oligomerized with R-Smad proteins upon TGF-β signaling and directly inhibited R-Smad activity, as assessed by Gal4-luciferase reporter assays. Mechanistically, Smad7 competes with Smad4 to associate with R-Smads and recruits the E3 ubiquitin ligase NEDD4L to activated R-Smads, leading to their polyubiquitination and proteasomal degradation. Similar to the R-Smad-Smad4 oligomerization, the interaction between R-Smads and Smad7 is mediated by their mad homology 2 (MH2) domains. A positive-charged basic region including the L3/β8 loop-strand module and adjacent amino acids in the MH2 domain of Smad7 is essential for the interaction. These results shed new light on the regulation of TGF-β signaling by Smad7.
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Affiliation(s)
- Xiaohua Yan
- From the State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084 China,
| | - Hongwei Liao
- From the State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Minzhang Cheng
- From the State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Xiaojing Shi
- From the State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Xia Lin
- Michael E. DeBakey Department of Surgery and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030
| | - Xin-Hua Feng
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, 310058 China, and
| | - Ye-Guang Chen
- From 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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19
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Zhao B, Chen YG. Regulation of TGF-β Signal Transduction. SCIENTIFICA 2014; 2014:874065. [PMID: 25332839 PMCID: PMC4190275 DOI: 10.1155/2014/874065] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 09/02/2014] [Indexed: 05/30/2023]
Abstract
Transforming growth factor-β (TGF-β) signaling regulates diverse cellular processes, including cell proliferation, differentiation, apoptosis, cell plasticity, and migration. TGF-β signaling can be mediated by Smad proteins or other signaling proteins such as MAP kinases and Akt. TGF-β signaling is tightly regulated at different levels along the pathways to ensure its proper physiological functions in different cells and tissues. Deregulation of TGF-β signaling has been associated with various kinds of diseases, such as cancer and tissue fibrosis. This paper focuses on our recent work on regulation of TGF-β signaling.
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Affiliation(s)
- Bing Zhao
- The State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Ye-Guang Chen
- The State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
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20
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Yin Yang 1 (YY1) synergizes with Smad7 to inhibit TGF-β signaling in the nucleus. SCIENCE CHINA-LIFE SCIENCES 2013; 57:128-36. [PMID: 24369345 DOI: 10.1007/s11427-013-4581-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 11/19/2013] [Indexed: 10/25/2022]
Abstract
As a prototype of the TGF-β superfamily cytokines, TGF-β is well known for its diverse roles in embryogenesis and adult tissue homeostasis. TGF-β evokes cellular responses by signaling mainly through cell membrane receptors and transcription factor R-Smads and Co-Smad (Smad4), while an inhibitory Smad, Smad7, acts as a critical negative regulator of TGF-β signaling. Smad7 antagonizes TGF-β signaling by regulating the stability or activity of the receptors or blocking the DNA binding of the functional R-Smad-Smad4 complex in the nucleus. However, the function of Smad7 in the nucleus is not fully understood. Yin Yang 1 (YY1) is a ubiquitously expressed transcription factor with multiple functions. It has been reported that YY1 can inhibit Smad-dependent transcriptional responses and TGF-β/BMP-induced cell differentiation independently of its DNA binding ability. In this study, we found that Smad7 interacts with YY1 and the interaction is attenuated by TGF-β signaling. Reporter assays and target gene expression analyses revealed that Smad7 and YY1 act in concert to inhibit TGF-β-induced transcription in the nucleus. Furthermore, Smad7 could enhance the interaction of YY1 with the histone deacetylase HDAC1. Consistently, YY1 and HDAC1 augmented the transcription repression activity of Smad7 in Gal4-luciferase reporter analysis. Therefore, our findings define a novel mechanism of Smad7 and YY1 to antagonize TGF-β signaling.
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21
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Oncogenic PAK4 regulates Smad2/3 axis involving gastric tumorigenesis. Oncogene 2013; 33:3473-84. [PMID: 23934187 DOI: 10.1038/onc.2013.300] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 06/10/2013] [Accepted: 06/17/2013] [Indexed: 12/31/2022]
Abstract
The alteration of p21-activated kinase 4 (PAK4) and transforming growth factor-beta (TGF-β) signaling effector Smad2/3 was detected in several types of tumors, which acts as oncogenic factor and tumor suppressor, but the relationship between these events has not been explored. Here, we demonstrate that PAK4 interacts with and modulates phosphorylation of Smad2/3 via both kinase-dependent and kinase-independent mechanisms, which attenuate Smad2/3 axis transactivation and TGF-β-mediated growth inhibition in gastric cancer cells. First, PAK4 interaction with Smad2/3, which is independent of PAK4 kinase activity, blocks TGF-β1-induced phosphorylation of Smad2 Ser465/467 or Smad3 Ser423/425 and the consequent activation. In addition, PAK4 phosphorylates Smad2 on Ser465, leading to the degradation of Smad2 through ubiquitin-proteasome-dependent pathway under hepatocyte growth factor (HGF) stimulation. Interestingly, PAK4 expression correlates negatively with phospho-Ser465/467 Smad2 but positively with phospho-Ser465 Smad2 in gastric cancer tissues. Furthermore, the expressions of HGF, phospho-Ser474 PAK4 and phospho-Ser465 Smad2 are markedly increased in gastric cancer tissues, and the expression of Smad2 is decreased in gastric cancer tissues. Our results document an oncogenic role of PAK4 in repression of Smad2/3 transactivation that involved in tumorigenesis, and suggest PAK4 as a potential therapeutic target for gastric cancer.
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Chen G, Chen X, Sukumar A, Gao B, Curley J, Schnaper HW, Ingram AJ, Krepinsky JC. TGFβ receptor I transactivation mediates stretch-induced Pak1 activation and CTGF upregulation in mesangial cells. J Cell Sci 2013; 126:3697-712. [PMID: 23781022 DOI: 10.1242/jcs.126714] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Increased intraglomerular pressure is an important pathogenic determinant of kidney fibrosis in the progression of chronic kidney disease, and can be modeled by exposing glomerular mesangial cells (MC) to mechanical stretch. MC produce extracellular matrix and profibrotic cytokines, including connective tissue growth factor (CTGF) when stretched. We show that p21-activated kinase 1 (Pak1) is activated by stretch in MC in culture and in vivo in a process marked by elevated intraglomerular pressures. Its activation is essential for CTGF upregulation. Rac1 is an upstream regulator of Pak1 activation. Stretch induces transactivation of the type I transforming growth factor β1 receptor (TβRI) independently of ligand binding. TβRI transactivation is required not only for Rac1/Pak1 activation, but also for activation of the canonical TGFβ signaling intermediate Smad3. We show that Smad3 activation is an essential requirement for CTGF upregulation in MC under mechanical stress. Pak1 regulates Smad3 C-terminal phosphorylation and transcriptional activation. However, a second signaling pathway, that of RhoA/Rho-kinase and downstream Erk activation, is also required for stretch-induced CTGF upregulation in MC. Importantly, this is also regulated by Pak1. Thus, Pak1 serves as a novel central mediator in the stretch-induced upregulation of CTGF in MC.
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Affiliation(s)
- Guang Chen
- Division of Nephrology, St. Joseph's Hospital, McMaster University, Hamilton, ON L8N 4A6, Canada
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Sato M, Matsuda Y, Wakai T, Kubota M, Osawa M, Fujimaki S, Sanpei A, Takamura M, Yamagiwa S, Aoyagi Y. P21-activated kinase-2 is a critical mediator of transforming growth factor-β-induced hepatoma cell migration. J Gastroenterol Hepatol 2013; 28:1047-55. [PMID: 23425030 DOI: 10.1111/jgh.12150] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/15/2013] [Indexed: 01/26/2023]
Abstract
BACKGROUND AND AIM Transforming growth factor-β (TGF-β) has been shown to play a central role in the promotion of cell motility, but its functional mechanism has remained unclear. With the aim of investigating the diagnostic and treatment modalities for patients with hepatocellular carcinoma (HCC), the signaling pathway that may contribute to TGF-β-mediated cell invasion in hepatoma cells was evaluated. METHODS Three hepatoma cell lines, HepG2, PLC/PRF/5, and HLF, were treated with TGF-β, and the involvement of the non-canonical TGF-β pathway was analyzed by cell migration assays. HepG2 cells were treated with a p21-activated kinase-2 (PAK2)-targeting small interfering RNA and analyzed for their cell motility. The relationships between the PAK2 status and the clinicopathological characteristics of 62 HCC patients were also analyzed. RESULTS The cell migration assays showed that Akt is a critical regulator of TGF-β-mediated cell migration. Western blotting analyses showed that TGF-β stimulated Akt and PAK2 in all three hepatoma cell lines, and phosphorylated PAK2 was blocked by Akt inhibitor. Suppression of PAK2 expression by small interfering RNA resulted in increased focal adhesions with significantly repressed cell migration in the presence of TGF-β. Clinicopathological analyses showed that the phosphorylation level of PAK2 was closely associated with tumor progression, metastasis, and early recurrence of HCC. CONCLUSIONS PAK2 may be a critical mediator of TGF-β-mediated hepatoma cell migration, and may represent a potential target for the treatment of HCC.
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Affiliation(s)
- Munehiro Sato
- Division of Gastroenterology and Hepatology, Niigata University Graduate School of Medical and Dental Sciences, Japan
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