scholarly journals Pathogenesis of Enamel-Renal Syndrome Associated Gingival Fibromatosis: A Proteomic Approach

2021 ◽  
Vol 12 ◽  
Author(s):  
Victor Simancas Escorcia ◽  
Clément Guillou ◽  
Lilia Abbad ◽  
Louise Derrien ◽  
Claudio Rodrigues Rezende Costa ◽  
...  

The enamel renal syndrome (ERS) is a rare disorder featured by amelogenesis imperfecta, gingival fibromatosis and nephrocalcinosis. ERS is caused by bi-allelic mutations in the secretory pathway pseudokinase FAM20A. How mutations in FAM20A may modify the gingival connective tissue homeostasis and cause fibromatosis is currently unknown. We here analyzed conditioned media of gingival fibroblasts (GFs) obtained from four unrelated ERS patients carrying distinct mutations and control subjects. Secretomic analysis identified 109 dysregulated proteins whose abundance had increased (69 proteins) or decreased (40 proteins) at least 1.5-fold compared to control GFs. Proteins over-represented were mainly involved in extracellular matrix organization, collagen fibril assembly, and biomineralization whereas those under-represented were extracellular matrix-associated proteins. More specifically, transforming growth factor-beta 2, a member of the TGFβ family involved in both mineralization and fibrosis was strongly increased in samples from GFs of ERS patients and so were various known targets of the TGFβ signaling pathway including Collagens, Matrix metallopeptidase 2 and Fibronectin. For the over-expressed proteins quantitative RT-PCR analysis showed increased transcript levels, suggesting increased synthesis and this was further confirmed at the tissue level. Additional immunohistochemical and western blot analyses showed activation and nuclear localization of the classical TGFβ effector phospho-Smad3 in both ERS gingival tissue and ERS GFs. Exposure of the mutant cells to TGFB1 further upregulated the expression of TGFβ targets suggesting that this pathway could be a central player in the pathogenesis of the ERS gingival fibromatosis.In conclusion our data strongly suggest that TGFβ -induced modifications of the extracellular matrix contribute to the pathogenesis of ERS. To our knowledge this is the first proteomic-based analysis of FAM20A-associated modifications.

1995 ◽  
Vol 108 (6) ◽  
pp. 2153-2162 ◽  
Author(s):  
J.F. Talts ◽  
A. Weller ◽  
R. Timpl ◽  
M. Ekblom ◽  
P. Ekblom

We have here studied the composition and regulation of stromal extracellular matrix components in an experimental tumor model. Nude mice were inoculated with WCCS-1 cells, a human Wilms' tumor cell line. In the formed tumors the stroma was found to contain mesenchymal extracellular matrix proteins such as tenascin-C, fibulins-1 and 2 and fibronectin, but no nidogen. Nidogen was confined to basement membranes of tumor blood vessels. Since glucocorticoids have been shown to downregulate tenascin-C expression in vitro, we tested whether dexamethasone can influence biosynthesis of extracellular matrix components during tumor formation in vivo. A downregulation of tenascin-C mRNA and an upregulation of fibronectin mRNA expression by dexamethasone was noted. Transforming growth factor-beta 1 mRNA levels were unaffected by the dexamethasone treatment. Glucocorticoids can thus downregulate tenascin-C synthesis although local stimulatory growth factors are present. The competition between a negative and a positive extrinsic factor on synthesis of stromal extracellular matrix components was studied in a fibroblast/preadipocyte cell line. Transforming growth factor-beta 1 stimulated tenascin-C synthesis but did not affect fibronectin or fibulin-2 synthesis. Dexamethasone at high concentrations could completely suppress the effect of transforming growth factor-beta 1 on tenascin-C mRNA expression. Transforming growth factor-beta 1 could in turn overcome the downregulation of tenascin-C mRNA expression caused by a lower concentration of dexamethasone. We therefore suggest that the limited expression of tenascin-C in part is due to a continuous suppression by physiological levels of glucocorticoids, which can be overcome by local stimulatory growth factors when present in sufficient amounts.


2018 ◽  
Vol 29 (18) ◽  
pp. 2165-2175 ◽  
Author(s):  
Elizabeth Monaghan-Benson ◽  
Erika S. Wittchen ◽  
Claire M. Doerschuk ◽  
Keith Burridge

Idiopathic pulmonary fibrosis (IPF) is an incurable disease of the lung that is characterized by excessive deposition of extracellular matrix (ECM), resulting in disruption of normal lung function. The signals regulating fibrosis include both transforming growth factor beta (TGF-β) and tissue rigidity and a major signaling pathway implicated in fibrosis involves activation of the GTPase RhoA. During studies exploring how elevated RhoA activity is sustained in IPF, we discovered that not only is RhoA activated by profibrotic stimuli but also that the expression of Rnd3, a major antagonist of RhoA activity, and the activity of p190RhoGAP (p190), a Rnd3 effector, are both suppressed in IPF fibroblasts. Restoration of Rnd3 levels in IPF fibroblasts results in an increase in p190 activity, a decrease in RhoA activity and a decrease in the overall fibrotic phenotype. We also find that treatment with IPF drugs nintedanib and pirfenidone decreases the fibrotic phenotype and RhoA activity through up-regulation of Rnd3 expression and p190 activity. These data provide evidence for a pathway in IPF where fibroblasts down-regulate Rnd3 levels and p190 activity to enhance RhoA activity and drive the fibrotic phenotype.


2018 ◽  
Vol 243 (7) ◽  
pp. 601-612 ◽  
Author(s):  
Nathan Cho ◽  
Shadi E Razipour ◽  
Megan L McCain

Cardiac fibroblasts and their activated derivatives, myofibroblasts, play a critical role in wound healing after myocardial injury and often contribute to long-term pathological outcomes, such as excessive fibrosis. Thus, defining the microenvironmental factors that regulate the phenotype of cardiac fibroblasts and myofibroblasts could lead to new therapeutic strategies. Both chemical and biomechanical cues have previously been shown to induce myofibroblast differentiation in many organs and species. For example, transforming growth factor beta 1, a cytokine secreted by neutrophils, and rigid extracellular matrix environments have both been shown to promote differentiation. However, the relative contributions of transforming growth factor beta 1 and extracellular matrix rigidity, two hallmark cues in many pathological myocardial microenvironments, to the phenotype of human cardiac fibroblasts are unclear. We hypothesized that transforming growth factor beta 1 and rigid extracellular matrix environments would potentially have a synergistic effect on the differentiation of human cardiac fibroblasts to myofibroblasts. To test this, we seeded primary human adult cardiac fibroblasts onto coverslips coated with polydimethylsiloxane of various elastic moduli, introduced transforming growth factor beta 1, and longitudinally quantified cell phenotype by measuring expression of α-smooth muscle actin, the most robust indicator of myofibroblasts. Our data indicate that, although extracellular matrix rigidity influenced differentiation after one day of transforming growth factor beta 1 treatment, ultimately transforming growth factor beta 1 superseded extracellular matrix rigidity as the primary regulator of myofibroblast differentiation. We also measured expression of POSTN, FAP, and FSP1, proposed secondary indicators of fibroblast/myofibroblast phenotypes. Although these genes partially trended with α-smooth muscle actin expression, they were relatively inconsistent. Finally, we demonstrated that activated myofibroblasts incompletely revert to a fibroblast phenotype after they are re-plated onto new surfaces without transforming growth factor beta 1, suggesting differentiation is partially reversible. Our results provide new insights into how microenvironmental cues affect human cardiac fibroblast differentiation in the context of myocardial pathology, which is important for identifying effective therapeutic targets and dictating supporting cell phenotypes for engineered human cardiac disease models. Impact statement Heart disease is the leading cause of death worldwide. Many forms of heart disease are associated with fibrosis, which increases extracellular matrix (ECM) rigidity and compromises cardiac output. Fibrotic tissue is synthesized primarily by myofibroblasts differentiated from fibroblasts. Thus, defining the cues that regulate myofibroblast differentiation is important for understanding the mechanisms of fibrosis. However, previous studies have focused on non-human cardiac fibroblasts and have not tested combinations of chemical and mechanical cues. We tested the effects of TGF-β1, a cytokine secreted by immune cells after injury, and ECM rigidity on the differentiation of human cardiac fibroblasts to myofibroblasts. Our results indicate that differentiation is initially influenced by ECM rigidity, but is ultimately superseded by TGF-β1. This suggests that targeting TGF-β signaling pathways in cardiac fibroblasts may have therapeutic potential for attenuating fibrosis, even in rigid microenvironments. Additionally, our approach can be leveraged to engineer more precise multi-cellular human cardiac tissue models.


1988 ◽  
Vol 8 (10) ◽  
pp. 4234-4242
Author(s):  
B L Allen-Hoffmann ◽  
C L Crankshaw ◽  
D F Mosher

Transforming growth factor beta (TGF-beta) enhances the cell surface binding of 125I-fibronectin by cultured human fibroblasts. The effect of TGF-beta on cell surface binding was maximal after 2 h of exposure to TFG-beta and did not require epidermal growth factor or protein synthesis. The enhancement was dose dependent and was found with the 125I-labeled 70-kilodalton amino-terminal fragment of fibronectin as well as with 125I-fibronectin. Treatment of cultures with TGF-beta for 6 h resulted in a threefold increase in the estimated number of fibronectin binding sites. The increase in number of binding sites was accompanied by an increased accumulation of labeled fibronectin in detergent-insoluble extracellular matrix. The effect of TGF-beta was biphasic; after 6 h of exposure, less labeled fibronectin bound to treated cultures than to control cultures. Exposure of cells to TGF-beta for greater than 6 h caused a two- to threefold increase in the accumulation of cellular fibronectin in culture medium as detected by a quantitative enzyme-linked immunosorbent assay. The second phase of the biphasic effect and the increase in soluble cellular fibronectin were blocked by cycloheximide. Immunofluorescence staining of fibroblast cultures with antifibronectin revealed that TGF-beta caused a striking increase in fibronectin fibrils. The 70-kilodalton amino-terminal fragment of fibronectin, which blocks incorporation of fibronectin into extracellular matrix, blocked anchorage-independent growth of NRK-49F cells in the presence of epidermal growth factor. Our results show that an increase in the binding and rate of assembly of exogenous fibronectin is an early event preceding the increase in expression of extracellular matrix proteins. Such an early increase in cell surface binding of exogenous fibronectin may be a mechanism whereby TGF-beta can modify extracellular matrix characteristics rapidly after tissue injury or during embryonic morphogenesis.


ESC CardioMed ◽  
2018 ◽  
pp. 713-715
Author(s):  
Dorien Schepers ◽  
Bart Loeys

Marfan syndrome is an autosomal dominant, multisystemic disorder, presenting with skeletal, ocular, and cardiovascular symptoms. This connective tissue disease is caused by mutations in FBN1, encoding fibrillin-1, which is an important extracellular matrix protein. Marfan syndrome shows significant clinical overlap with Loeys–Dietz syndrome, which is caused by genetic defects in components of the transforming growth factor-beta pathway: TGFBR1, TGFBR2, TGFB2, TGFB3, SMAD2, and SMAD3. Overlapping clinical features between Marfan syndrome and Loeys–Dietz syndrome include aortic root aneurysm, arachnodactyly, scoliosis, and pectus deformity.


1994 ◽  
Vol 266 (6) ◽  
pp. F829-F842 ◽  
Author(s):  
K. Sharma ◽  
F. N. Ziyadeh

Transforming growth factor-beta (TGF-beta) is a prototypical multifunctional cytokine, with growth being only one of its many functions. Its receptors and actions are germane to almost every cell in the body involved in tissue injury and repair, and its effects are best understood in the context of a cellular response to a changing environment. The broad areas in which TGF-beta plays a crucial role include cell proliferation and extracellular matrix production. TGF-beta is a key regulatory molecule in the control of the activity of fibroblasts and has been implicated in several disease states characterized by excessive fibrosis. In the kidney, TGF-beta promotes tubuloepithelial cell hypertrophy and regulates the glomerular production of almost every known molecule of the extracellular matrix, including collagens, fibronectin, tenascin, and proteoglycans, as well as the integrins that are the receptors for these molecules. Furthermore, TGF-beta blocks the destruction of newly synthesized extracellular matrix by upregulating the synthesis of protease inhibitors and downregulating the synthesis of matrix-degrading proteases such as stromelysin and collagenase. As will be discussed, there is a strong body of in vitro and in vivo evidence suggesting that persistent overproduction of TGF-beta 1 in glomeruli after the acute inflammatory stage of glomerulonephritis causes glomerulosclerosis. TGF-beta may also be important in a variety of other chronic renal disorders characterized by hypertrophy and sclerosis, such as diabetic nephropathy. In this review we will attempt to offer a basic understanding of the cellular and molecular biology of TGF-beta and its receptors, with special focus on the role of the TGF-beta system in the kidney during development, growth, and disease.


1991 ◽  
Vol 11 (2) ◽  
pp. 972-978 ◽  
Author(s):  
M Laiho ◽  
L Rönnstrand ◽  
J Heino ◽  
J A Decaprio ◽  
J W Ludlow ◽  
...  

Treatment of Mv1Lu mink lung epithelial cells with transforming growth factor-beta 1 (TGF-beta 1) prevents phosphorylation of the retinoblastoma susceptibility gene product, RB, in late G1 phase of the cell cycle, which is thought to retain RB in a growth-suppressive state. This effect is paralleled by cell cycle arrest in late G1 (M. Laiho, J. A. DeCapric, J. W. Ludlow, D. M. Livingston, and J. Massagué, Cell 62:175-185, 1990). Arrest can be prevented by expression of simian virus 40 T antigen, which binds to underphosphorylated RB, presumably blocking its growth-suppressive activity. The response of cells to TGF-beta 1, however, is complex and includes changes in the levels of expression of genes encoding nuclear transcription factors and extracellular matrix components. To define the relationships among various components of the TGF-beta 1 response, we have investigated the effect of TGF-beta 1 on cells whose growth-inhibitory response to this factor is prevented by T antigen. TGF-beta 1 addition to exponentially growing Mv1Lu cells increased the levels of junB mRNA and of three extracellular matrix proteins: plasminogen activator inhibitor-1, fibronectin, and thrombospondin. Kinetically, the effects on junB and plasminogen activator inhibitor-1 expression occurred faster (half-maximal at 1 to 2 h) than the effects on fibronectin and thrombospondin expression (half-maximal at 6 to 10 h). These effects either preceded or overlapped, respectively, the withdrawal of Mv1Lu cells from the cell cycle. Expression of a transfected T-antigen gene in Mv1Lu cells, however, did not prevent any of these responses to TGF-beta 1. The results indcate that TGF-B1-stimulated expression of junB and extracellular matrix proteins in Mv1Lu cells can occur independently of the T-antigen-sensitive events that lead to growth arrest.


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