SnoN as a novel negative regulator of TGF-β/Smad signaling: a target for tailoring organ fibrosis

2015 ◽  
Vol 308 (2) ◽  
pp. H75-H82 ◽  
Author(s):  
Matthew R. Zeglinski ◽  
Mark Hnatowich ◽  
Davinder S. Jassal ◽  
Ian M. C. Dixon

Remodeling of the extracellular matrix is beneficial during the acute wound healing stage following tissue injury. In the short term, resident fibroblasts and myofibroblasts regulate the matrix remodeling process through production of matricellular protein components that provide structural support to the damaged tissue. This process is largely governed by the transforming growth factor-β1 (TGF-β1) pathway, a critical mediator of the remodeling process. In the long term, chronic activation of the TGF-β1 pathway promotes excessive synthesis and deposition of matrix proteins, including fibrillar collagens, which ultimately leads to organ failure. SnoN (and its alternatively-spliced isoforms SnoN2, SnoA, and SnoI) is one of four members of a family of negative regulators of TGF-β1 signaling that includes Ski and functional Smad-suppressing elements on chromosomes 15 and 18. SnoN has been shown to be structurally and functionally similar to Ski and has been demonstrated to directly interact with Ski to abrogate gene expression. Despite this, little progress has been made in delineating a specific role for SnoN in the regulation of myofibroblast phenotype and function. This review outlines the current body of knowledge of what we refer to as the “Ski-Sno superfamily,” with a focus on the structural and functional importance of SnoN in mediating the fibrotic response by myofibroblasts following tissue injury.

Author(s):  
Yiping Hu ◽  
Juan He ◽  
Lianhua He ◽  
Bihua Xu ◽  
Qingwen Wang

AbstractTransforming growth factor-β (TGF-β) plays a critical role in the pathological processes of various diseases. However, the signaling mechanism of TGF-β in the pathological response remains largely unclear. In this review, we discuss advances in research of Smad7, a member of the I-Smads family and a negative regulator of TGF-β signaling, and mainly review the expression and its function in diseases. Smad7 inhibits the activation of the NF-κB and TGF-β signaling pathways and plays a pivotal role in the prevention and treatment of various diseases. Specifically, Smad7 can not only attenuate growth inhibition, fibrosis, apoptosis, inflammation, and inflammatory T cell differentiation, but also promotes epithelial cells migration or disease development. In this review, we aim to summarize the various biological functions of Smad7 in autoimmune diseases, inflammatory diseases, cancers, and kidney diseases, focusing on the molecular mechanisms of the transcriptional and posttranscriptional regulation of Smad7.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 336
Author(s):  
Roberta Melchionna ◽  
Paola Trono ◽  
Annalisa Tocci ◽  
Paola Nisticò

Human tissues, to maintain their architecture and function, respond to injuries by activating intricate biochemical and physical mechanisms that regulates intercellular communication crucial in maintaining tissue homeostasis. Coordination of the communication occurs through the activity of different actin cytoskeletal regulators, physically connected to extracellular matrix through integrins, generating a platform of biochemical and biomechanical signaling that is deregulated in cancer. Among the major pathways, a controller of cellular functions is the cytokine transforming growth factor β (TGFβ), which remains a complex and central signaling network still to be interpreted and explained in cancer progression. Here, we discuss the link between actin dynamics and TGFβ signaling with the aim of exploring their aberrant interaction in cancer.


2007 ◽  
Vol 67 (4) ◽  
pp. 559-562 ◽  
Author(s):  
K Warstat ◽  
T Pap ◽  
G Klein ◽  
S Gay ◽  
W K Aicher

We showed previously that the attachment of synovial fibroblasts to laminin (LM)-111 in the presence of transforming growth factor-β induces significant expression of the matrix metalloproteinase (MMP)-3. Here we go on to investigate the regulation of additional MMPs and their specific tissue inhibitors of matrix proteases (TIMPs). Changes in steady-state mRNA levels encoding TIMPs and MMPs were investigated by quantitative reverse transcription–polymerase chain reaction. Production of MMPs was monitored by a multiplexed immunoarray. Signal transduction pathways were studied by immunoblotting. Attachment of synovial fibroblasts to LM-111 in the presence of transforming growth factor-β induced significant increases in MMP-3 mRNA (12.35-fold, p<0.001) and protein (mean 62 ng/ml, sixfold, p<0.008) and in expression of MMP-10 mRNA (11.68-fold, p<0.05) and protein (54 ng/ml, 20-fold, p⩾0.02). All other TIMPs and MMPs investigated failed to show this LM-111-facilitated transforming growth factor-β response. No phosphorylation of nuclear factor-κB was observed. We conclude that co-stimulation of synovial fibroblasts by LM-111 together with transforming growth factor-β suffices to induce significant expression of MMP-3 and MMP-10 by synovial fibroblasts and that this induction is independent of nuclear factor-κB phosphorylation.


2000 ◽  
Vol 7 (2-4) ◽  
pp. 89-101 ◽  
Author(s):  
Elke Schönherr ◽  
Heinz-JüRgen Hausser

The extracellular matrix (ECM) as well as soluble mediators like cytokines can influence the behavior of cells in very distinct as well as cooperative ways. One group of ECM molecules which shows an especially broad cooperativety with cytokines and growth factors are the proteoglycans. Proteoglycans can interact with their core proteins as well as their glycosaminoglycan chains with cytokines. These interactions can modify the binding of cytokines to their cell surface receptors or they can lead to the storage of the soluble factors in the matrix. Proteoglycans themselves may even have cytokine activity. In this review we describe different proteoglycans and their interactions and relationships with cytokines and we discuss in more detail the extracellular regulation of the activity of transforming growth factor-β (TGF-β) by proteoglycans and other ECM molecules. In the third part the interaction of heparan sulfate chains with fibroblast growth factor-2 (FGF-2, basic FGF) as a prototype example for the interaction of heparin-binding cytokines with heparan sulfate proteoglycans is presented to illustrate the different levels of mutual dependence of the cytokine network and the ECM.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Patrick William Jaynes ◽  
Prasanna Vasudevan Iyengar ◽  
Sarah Kit Leng Lui ◽  
Tuan Zea Tan ◽  
Natali Vasilevski ◽  
...  

Abstract Systematic control of the transforming growth factor-β (TGFβ) pathway is essential to keep the amplitude and the intensity of downstream signalling at appropriate levels. Ubiquitination plays a crucial role in the general regulation of this pathway. Here we identify the deubiquitinating enzyme OTUD4 as a transcriptional target of the TGFβ pathway that functions through a positive feedback loop to enhance overall TGFβ activity. Interestingly we demonstrate that OTUD4 functions through both catalytically dependent and independent mechanisms to regulate TGFβ activity. Specifically, we find that OTUD4 enhances TGFβ signalling by promoting the membrane presence of TGFβ receptor I. Furthermore, we demonstrate that OTUD4 inactivates the TGFβ negative regulator SMURF2 suggesting that OTUD4 regulates multiple nodes of the TGFβ pathway to enhance TGFβ activity.


2009 ◽  
Vol 297 (2) ◽  
pp. F237-F243 ◽  
Author(s):  
Paul W. Sanders

Animal and human studies support an untoward effect of excess dietary NaCl (salt) intake on cardiovascular and renal function and life span. Recent work has promoted the concept that the endothelium, in particular, reacts to changes in dietary salt intake through a complex series of events that are independent of blood pressure and the renin-angiotensin-aldosterone axis. The cellular signaling events culminate in the intravascular production of transforming growth factor-β (TGF-β) and nitric oxide in response to increased salt intake. Plasticity of the endothelium is integral in the vascular remodeling consequences associated with excess salt intake, because nitric oxide serves as a negative regulator of TGF-β production. Impairment of nitric oxide production, such as occurs with endothelial dysfunction in a variety of disease states, results in unopposed excess vascular TGF-β production, which promotes reduced vascular compliance and augmented peripheral arterial constriction and hypertension. Persistent alterations in vascular function promote the increase in cardiovascular events and reductions in renal function that reduce life span during increased salt intake.


2013 ◽  
Vol 304 (10) ◽  
pp. C995-C1001 ◽  
Author(s):  
Rani Watts ◽  
Virginia L. Johnsen ◽  
Jane Shearer ◽  
Dustin S. Hittel

Myostatin, a member of the transforming growth factor-β (TGF-β) superfamily of secreted proteins, is a potent negative regulator of myogenesis. Free myostatin induces the phosphorylation of the Smad family of transcription factors, which, in turn, regulates gene expression, via the canonical TGF-β signaling pathway. There is, however, emerging evidence that myostatin can regulate gene expression independent of Smad signaling. As such, we acquired global gene expression data from the gastrocnemius muscle of C57BL/6 mice following a 6-day treatment with recombinant myostatin compared with vehicle-treated animals. Of the many differentially expressed genes, the myostatin-associated decrease (−11.20-fold; P < 0.05) in the noncoding metastasis-associated lung adenocarcinoma transcript 1 (Malat1) was the most significant and the most intriguing because of numerous reports describing its novel role in regulating cell growth. We therefore sought to further characterize the role of Malat1 expression in skeletal muscle myogenesis. RT-PCR-based quantification of C2C12 and primary human skeletal muscle cells revealed a significant and persistent upregulation (4- to 7-fold; P < 0.05) of Malat1 mRNA during the differentiation of myoblasts into myotubes. Conversely, targeted knockdown of Malat1 using siRNA suppressed myoblast proliferation by arresting cell growth in the G0/G1phase. These results reveal Malat1 as novel downstream target of myostatin with a considerable ability to regulate myogenesis. The identification of new targets of myostatin will have important repercussions for regenerative biology through inhibition and/or reversal of muscle atrophy and wasting diseases.


2020 ◽  
Vol 13 (639) ◽  
pp. eaba3880 ◽  
Author(s):  
Cyril Anastasi ◽  
Patricia Rousselle ◽  
Maya Talantikite ◽  
Agnès Tessier ◽  
Caroline Cluzel ◽  
...  

Bone morphogenetic protein 1 (BMP-1) is an important metalloproteinase that synchronizes growth factor activation with extracellular matrix assembly during morphogenesis and tissue repair. The mechanisms by which BMP-1 exerts these effects are highly context dependent. Because BMP-1 overexpression induces marked phenotypic changes in two human cell lines (HT1080 and 293-EBNA cells), we investigated how BMP-1 simultaneously affects cell-matrix interactions and growth factor activity in these cells. Increasing BMP-1 led to a loss of cell adhesion that depended on the matricellular glycoprotein thrombospondin-1 (TSP-1). BMP-1 cleaved TSP-1 between the VWFC/procollagen-like domain and the type 1 repeats that mediate several key TSP-1 functions. This cleavage induced the release of TSP-1 C-terminal domains from the extracellular matrix and abolished its previously described multisite cooperative interactions with heparan sulfate proteoglycans and CD36 on HT1080 cells. In addition, BMP-1–dependent proteolysis potentiated the TSP-1–mediated activation of latent transforming growth factor–β (TGF-β), leading to increased signaling through the canonical SMAD pathway. In primary human corneal stromal cells (keratocytes), endogenous BMP-1 cleaved TSP-1, and the addition of exogenous BMP-1 enhanced cleavage, but this had no substantial effect on cell adhesion. Instead, processed TSP-1 promoted the differentiation of keratocytes into myofibroblasts and stimulated production of the myofibroblast marker α-SMA, consistent with the presence of processed TSP-1 in human corneal scars. Our results indicate that BMP-1 can both trigger the disruption of cell adhesion and stimulate TGF-β signaling in TSP-1–rich microenvironments, which has important potential consequences for wound healing and tumor progression.


Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1666
Author(s):  
Xueke Shi ◽  
Christian D. Young ◽  
Hongmei Zhou ◽  
Xiao-Jing Wang

Transforming growth factor-β (TGF-β) signaling is essential in embryo development and maintaining normal homeostasis. Extensive evidence shows that TGF-β activation acts on several cell types, including epithelial cells, fibroblasts, and immune cells, to form a pro-fibrotic environment, ultimately leading to fibrotic diseases. TGF-β is stored in the matrix in a latent form; once activated, it promotes a fibroblast to myofibroblast transition and regulates extracellular matrix (ECM) formation and remodeling in fibrosis. TGF-β signaling can also promote cancer progression through its effects on the tumor microenvironment. In cancer, TGF-β contributes to the generation of cancer-associated fibroblasts (CAFs) that have different molecular and cellular properties from activated or fibrotic fibroblasts. CAFs promote tumor progression and chronic tumor fibrosis via TGF-β signaling. Fibrosis and CAF-mediated cancer progression share several common traits and are closely related. In this review, we consider how TGF-β promotes fibrosis and CAF-mediated cancer progression. We also discuss recent evidence suggesting TGF-β inhibition as a defense against fibrotic disorders or CAF-mediated cancer progression to highlight the potential implications of TGF-β-targeted therapies for fibrosis and cancer.


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