Activation of the JNK/MAPK Signaling Pathway by TGF-β1 Enhances Neonatal Fc Receptor Expression and IgG Transcytosis

The neonatal Fc receptor (FcRn) transports maternal immunoglobulin G (IgG) to the foetus or newborn and protects the IgG from degradation. FcRn is expressed in several porcine tissues and cell types and its expression levels are regulated by immune and inflammatory events. IPEC-J2 cells are porcine intestinal columnar epithelial cells that were isolated from neonatal piglet mid-jejunum. We hypothesized that transforming growth factor β1 (TGF-β1) upregulated pFcRn expression in IPEC-J2 cells. To test this hypothesis, we treated IPEC-J2 cells with TGF-β1 and demonstrated that porcine FcRn (pFcRn) expression was significantly increased. SP600125, a specific mitogen-activated protein kinase (MAPK) inhibitor, reduced TGF-β1-induced pFcRn expression in IPEC-J2 cells. We performed luciferase reporter assays and showed that the c-JUN sensitive region of the pFcRn promoter gene was located between positions −1215 and −140. The c-JUN sequence, in combination with the pFcRn promoter, regulated luciferase reporter activity in response to TGF-β1 stimulation. Chromatin immunoprecipitation confirmed that there were three c-JUN binding sites in the pFcRn promoter. Furthermore, in addition to increased pFcRn expression, TGF-β1 also enhanced IgG transcytosis in IPEC-J2 cells. In summary, our data showed that the modulation of JNK/MAPK signaling by TGF-β1 was sufficient to upregulate pFcRn expression.

Download Full-text

JNK and p38 Inhibitors Prevent Transforming Growth Factor-β1-Induced Myofibroblast Transdifferentiation in Human Graves’ Orbital Fibroblasts

International Journal of Molecular Sciences ◽

10.3390/ijms22062952 ◽

2021 ◽

Vol 22 (6) ◽

pp. 2952

Author(s):

Tzu-Yu Hou ◽

Shi-Bei Wu ◽

Hui-Chuan Kau ◽

Chieh-Chih Tsai

Keyword(s):

Growth Factor ◽

Transforming Growth Factor ◽

Mapk Pathway ◽

Transforming Growth Factor Β1 ◽

Tissue Growth ◽

Mitogen Activated Protein Kinase ◽

Tissue Inhibitors Of Metalloproteinases ◽

Western Blots ◽

Orbital Fibroblasts ◽

Tgf Β1

Transforming growth factor-β1 (TGF-β1)-induced myofibroblast transdifferentiation from orbital fibroblasts is known to dominate tissue remodeling and fibrosis in Graves’ ophthalmopathy (GO). However, the signaling pathways through which TGF-β1 activates Graves’ orbital fibroblasts remain unclear. This study investigated the role of the mitogen-activated protein kinase (MAPK) pathway in TGF-β1-induced myofibroblast transdifferentiation in human Graves’ orbital fibroblasts. The MAPK pathway was assessed by measuring the phosphorylation of p38, c-Jun N-terminal kinase (JNK), and extracellular-signal-regulated kinase (ERK) by Western blots. The expression of connective tissue growth factor (CTGF), α-smooth muscle actin (α-SMA), and fibronectin representing fibrogenesis was estimated. The activities of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) responsible for extracellular matrix (ECM) metabolism were analyzed. Specific pharmacologic kinase inhibitors were used to confirm the involvement of the MAPK pathway. After treatment with TGF-β1, the phosphorylation levels of p38 and JNK, but not ERK, were increased. CTGF, α-SMA, and fibronectin, as well as TIMP-1 and TIMP-3, were upregulated, whereas the activities of MMP-2/-9 were inhibited. The effects of TGF-β1 on the expression of these factors were eliminated by p38 and JNK inhibitors. The results suggested that TGF-β1 could induce myofibroblast transdifferentiation in human Graves’ orbital fibroblasts through the p38 and JNK pathways.

Download Full-text

MKP2 inhibits TGF-β1-induced epithelial-to-mesenchymal transition in renal tubular epithelial cells through a JNK-dependent pathway

Clinical Science ◽

10.1042/cs20180602 ◽

2018 ◽

Vol 132 (21) ◽

pp. 2339-2355 ◽

Cited By ~ 6

Author(s):

Zhenzhen Li ◽

Xianghua Liu ◽

Fengyan Tian ◽

Ji Li ◽

Qingwei Wang ◽

...

Keyword(s):

Renal Fibrosis ◽

Epithelial To Mesenchymal Transition ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β1 ◽

Mitogen Activated Protein Kinase ◽

Jnk Signaling ◽

Mesenchymal Transition ◽

Amino Terminal ◽

Ureter Obstruction ◽

Tgf Β1

Epithelial-to-mesenchymal transition (EMT) is a phenotypic conversion that plays a crucial role in renal fibrosis leading to chronic renal failure. Mitogen-activated protein kinase phosphatase 2 (MKP2) is a member of the dual-specificity MKPs that regulate the MAP kinase pathway involved in transforming growth factor-β1 (TGF-β1)-induced EMT. However, the function of MKP2 in the regulation of EMT and the underlying mechanisms are still largely unknown. In the present study, we detected the expression of MKP2 in an animal model of renal fibrosis and evaluated the potential role of MKP2 in tubular EMT induced by TGF-β1. We found that the expression of MKP2 was up-regulated in the tubular epithelial of unilateral ureter obstruction rats. Meanwhile, we also demonstrated that TGF-β1 up-regulated MKP2 expression in NRK-52E cells during their EMT phenotype acquisition. Importantly, overexpression of MKP2 inhibited c-Jun amino terminal kinase (JNK) signaling and partially reversed EMT induced by TGF-β1. Moreover, reducing MKP2 expression enhanced JNK phosphorylation, promoted the E-cadherin suppression and induced α-SMA expression and fibronectin secretion in response to TGF-β1, which could be rescued by a JNK inhibitor. These results provide the first evidence that MKP2 is a negative feedback molecule induced by TGF-β1, and MKP2 overexpression inhibits TGF-β1-induced EMT through the JNK signaling pathway. MKP2 could be a promising target to be used in gene therapy for renal fibrosis.

Download Full-text

Effect of miR-195-5p on cardiomyocyte apoptosis in rats with heart failure by regulating TGF-β1/Smad3 signaling pathway

Bioscience Reports ◽

10.1042/bsr20200566 ◽

2020 ◽

Vol 40 (5) ◽

Author(s):

Chun Xie ◽

Huaxin Qi ◽

Lei Huan ◽

Yan Yang

Keyword(s):

Heart Failure ◽

Cardiac Function ◽

Signaling Pathway ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β1 ◽

Cardiomyocyte Apoptosis ◽

Luciferase Reporter ◽

Rat Cardiomyocytes ◽

Smad 3 ◽

Tgf Β1

Abstract Purpose: The present study set out to investigate the effect of miR-195-5p on cardiomyocyte apoptosis in rats with heart failure (HF) and its mechanism. Methods: HF rat model and hypoxia/reoxygenation (H/R) cardiomyocyte model were established. miR-195-5p expression and transforming growth factor-β1 (TGF-β1)/signal transduction protein (Smad)3 signaling pathway in HF rats and H/R cardiomyocytes were interfered. miR-195-5p expression was tested by Rt-PCR, TGF-β1/Smad3 signaling pathway related proteins were detected by Western Blot, apoptosis of HF rat cardiomyocytes was tested by TUNEL, and apoptosis of cardiomyocytes induced by H/R was checked by flow cytometry. Results: miR-195-5p was lowly expressed in myocardium of HF rats, while TGF-β1 and Smad3 proteins were high-expressed. Up-regulating miR-195-5p expression could obviously inhibit cardiomyocyte apoptosis of HF rats, improve their cardiac function, and inhibit activation of TGF-β1/Smad3 signaling pathway. Up-regulation of miR-195-5p expression or inhibition of TGF-β1/Smad3 signaling pathway could obviously inhibit H/R-induced cardiomyocyte apoptosis. Dual-luciferase reporter enzyme verified the targeted relationship between miR-195-5p and Smad3. Conclusion: miR-195-5p can inhibit cardiomyocyte apoptosis and improve cardiac function in HF rats by regulating TGF-β1/Smad3 signaling pathway, which may be a potential target for HF therapy.

Download Full-text

Osteoarthritic Synovial Fluid and TGF-β1 Induce Interleukin-18 in Articular Chondrocytes

Cartilage ◽

10.1177/1947603518796149 ◽

2018 ◽

Vol 11 (3) ◽

pp. 385-394 ◽

Cited By ~ 2

Author(s):

Camila B. Carballo ◽

Thiago R. P. Coelho ◽

Rosenilde C. de Holanda Afonso ◽

Jane Cristina de Oliveira Faria ◽

Tercia Alves ◽

...

Keyword(s):

Synovial Fluid ◽

Transforming Growth Factor ◽

Articular Chondrocytes ◽

Inflammatory Responses ◽

Transforming Growth Factor Β1 ◽

Receptor Expression ◽

Interleukin 18 ◽

Viability Analysis ◽

Pathophysiological Condition ◽

Tgf Β1

Objective Synovial fluid (SF) plays an important role in the maintenance of articular cartilage. SF is a dynamic reservoir of proteins derived from cartilage and synovial tissue; thus, its composition may serve as a biomarker that reflects the health and pathophysiological condition of the joint. The purpose of the current study was to evaluate the osteoarthritic synovial fluid (OASF) and transforming growth factor-β1 (TGF-β1) activity in articular chondrocytes catabolic and inflammatory responses. Design Chondrocytes were seeded at passage 2 and cultured for 72 hours under different conditions. Human chondrocytes were subjected to OASF while rat chondrocytes were subjected to either healthy synovial fluid (rSF) or TGF-β1 and then assigned for cell viability analysis. In addition, the effects of OASF and TGF-β1 on chondrocytes metalloprotease (MMP)-3 and MMP-13 and interleukin-18 (IL-18) expression were evaluated by immunocytochemistry, ELISA, and reverse transcriptase-polymerase chain reaction. Results SF from osteoarthritic patients significantly induced MMP-3, MMP-13, and IL-18 receptor expression in chondrocytes. To put in evidence the inflammatory activity of OASF, healthy chondrocytes from rat were cultured with TGF-β1. In the presence of TGF-β1 these cells started to express MMP-3, MMP-13, and IL-18 genes and attached to each other forming a chondrocyte aggregated structure. Healthy SF was able to maintain a typical monolayer of rounded chondrocytes with no inflammatory response. Conclusion In summary, these observations demonstrated that TGF-β1, one of the components of OASF, has a dual effect, acting in chondrocyte maintenance and also inducing inflammatory and catabolic properties of these cells.

Download Full-text

Rapid Up-Regulation of α4 Integrin-mediated Leukocyte Adhesion by Transforming Growth Factor-β1

Molecular Biology of the Cell ◽

10.1091/mbc.e02-05-0275 ◽

2003 ◽

Vol 14 (1) ◽

pp. 54-66 ◽

Cited By ~ 19

Author(s):

Rubén A. Bartolomé ◽

Francisco Sanz-Rodrı́guez ◽

Mar M. Robledo ◽

Andrés Hidalgo ◽

Joaquin Teixidó

Keyword(s):

Cell Migration ◽

Cell Adhesion ◽

Growth Factor ◽

Transforming Growth Factor ◽

Human Peripheral Blood ◽

Transforming Growth Factor Β1 ◽

Small Gtpase ◽

Mitogen Activated Protein Kinase ◽

Intracellular Camp ◽

Tgf Β1

The α4 integrins (α4β1 and α4β7) are cell surface heterodimers expressed mostly on leukocytes that mediate cell-cell and cell-extracellular matrix adhesion. A characteristic feature of α4 integrins is that their adhesive activity can be subjected to rapid modulation during the process of cell migration. Herein, we show that transforming growth factor-β1 (TGF-β1) rapidly (0.5–5 min) and transiently up-regulated α4 integrin-dependent adhesion of different human leukocyte cell lines and human peripheral blood lymphocytes (PBLs) to their ligands vascular cell adhesion molecule-1 (VCAM-1) and connecting segment-1/fibronectin. In addition, TGF-β1 enhanced the α4 integrin-mediated adhesion of PBLs to tumor necrosis factor-α–treated human umbilical vein endothelial cells, indicating the stimulation of α4β1/VCAM-1 interaction. Although TGF-β1 rapidly activated the small GTPase RhoA and the p38 mitogen-activated protein kinase, enhanced adhesion did not require activation of both signaling molecules. Instead, polymerization of actin cytoskeleton triggered by TGF-β1 was necessary for α4 integrin-dependent up-regulated adhesion, and elevation of intracellular cAMP opposed this up-regulation. Moreover, TGF-β1 further increased cell adhesion mediated by α4 integrins in response to the chemokine stromal cell-derived factor-1α. These data suggest that TGF-β1 can potentially contribute to cell migration by dynamically regulating cell adhesion mediated by α4 integrins.

Download Full-text

Melatonin Inhibits Transforming Growth Factor-β1-Induced Epithelial–Mesenchymal Transition in AML12 Hepatocytes

Biology ◽

10.3390/biology8040084 ◽

2019 ◽

Vol 8 (4) ◽

pp. 84 ◽

Cited By ~ 1

Author(s):

Kim ◽

Park ◽

Kim ◽

Leem ◽

Park

Keyword(s):

Growth Factor ◽

Transforming Growth Factor ◽

Epithelial Mesenchymal Transition ◽

Protective Action ◽

Transforming Growth Factor Β1 ◽

Membrane Receptors ◽

Mitogen Activated Protein Kinase ◽

Independent Manner ◽

Mesenchymal Transition ◽

Tgf Β1

Recent studies showed that melatonin, a well-known pineal hormone that modulates the circadian rhythm, exerts beneficial effects against liver fibrosis. However, mechanisms for its protective action against the fibrotic processes remain incompletely understood. Here, we aimed to explore the effects of the hormone on transforming growth factor-β1 (TGF-β1)-stimulated epithelial–mesenchymal transition (EMT) in AML12 hepatocytes. Pretreatment with melatonin dose-dependently reversed downregulation of an epithelial marker and upregulation of mesenchymal markers after TGF-β1 stimulation. Additionally, melatonin dose-dependently suppressed an increased phosphorylation of Smad2/3 after TGF-β1 treatment. Besides the canonical Smad signaling pathway, an increase in phosphorylation of extracellular signal-regulated kinase 1/2 and p38 was also dose-dependently attenuated by melatonin. The suppressive effect of the hormone on EMT stimulated by TGF-β1 was not affected by luzindole, an antagonist of melatonin membrane receptors, suggesting that its membrane receptors are not required for the inhibitory action of melatonin. Moreover, melatonin suppressed elevation of intracellular reactive oxygen species (ROS) levels in TGF-β1-treated cells. Finally, TGF-β1-stimulated EMT was also inhibited by the antioxidant N-acetylcysteine. Collectively, these results suggest that melatonin prevents TGF-β1-stimulated EMT through suppression of Smad and mitogen-activated protein kinase signaling cascades by deactivating ROS-dependent mechanisms in a membrane receptor-independent manner.

Download Full-text

Plakophilin-2 loss promotes TGF-β1/p38 MAPK-dependent fibrotic gene expression in cardiomyocytes

The Journal of Cell Biology ◽

10.1083/jcb.201507018 ◽

2016 ◽

Vol 212 (4) ◽

pp. 425-438 ◽

Cited By ~ 41

Author(s):

Adi D. Dubash ◽

Chen Y. Kam ◽

Brian A. Aguado ◽

Dipal M. Patel ◽

Mario Delmar ◽

...

Keyword(s):

Gene Expression ◽

P38 Mapk ◽

Electromechanical Coupling ◽

Transforming Growth Factor ◽

Mapk Signaling ◽

Conditional Knockout ◽

Mitogen Activated Protein Kinase ◽

Junctional Complex ◽

Plakophilin 2 ◽

Tgf Β1

Members of the desmosome protein family are integral components of the cardiac area composita, a mixed junctional complex responsible for electromechanical coupling between cardiomyocytes. In this study, we provide evidence that loss of the desmosomal armadillo protein Plakophilin-2 (PKP2) in cardiomyocytes elevates transforming growth factor β1 (TGF-β1) and p38 mitogen-activated protein kinase (MAPK) signaling, which together coordinate a transcriptional program that results in increased expression of profibrotic genes. Importantly, we demonstrate that expression of Desmoplakin (DP) is lost upon PKP2 knockdown and that restoration of DP expression rescues the activation of this TGF-β1/p38 MAPK transcriptional cascade. Tissues from PKP2 heterozygous and DP conditional knockout mouse models also exhibit elevated TGF-β1/p38 MAPK signaling and induction of fibrotic gene expression in vivo. These data therefore identify PKP2 and DP as central players in coordination of desmosome-dependent TGF-β1/p38 MAPK signaling in cardiomyocytes, pathways known to play a role in different types of cardiac disease, such as arrhythmogenic or hypertrophic cardiomyopathy.

Download Full-text

Activation of Transforming Growth Factor β1 (TGF-β1) Released by Platelets Is Enhanced by Shear and Occurs in Platelet-Rich Thrombi In Vivo.

Blood ◽

10.1182/blood.v110.11.3632.3632 ◽

2007 ◽

Vol 110 (11) ◽

pp. 3632-3632

Author(s):

Jasimuddin Ahamed ◽

Nathalie Burg ◽

Christin Janczak ◽

Jihong Li ◽

Barry S. Coller

Keyword(s):

Growth Factor ◽

Transforming Growth Factor ◽

Thrombus Formation ◽

Transforming Growth Factor Β1 ◽

Sharp Contrast ◽

Luciferase Reporter ◽

Plasminogen Activator Inhibitor 1 ◽

Total N ◽

Tgf Β1

Abstract Platelets contain 40–100 times as much transforming growth factor β1 (TGF-β1) as other cells, and release it as an inactive (latent) complex. Although several TGF-β1 activating factors have been identified in various cell types, it is still not known whether and how platelet TGF-β1 becomes activated in vivo. In the present study, cell-free human washed platelet releasates (supernatant after stimulation with thrombin 0.125U/ml for 5 min) or serum samples were subjected to either stirring (1,200 rpm) in an aggregometer or a shear stress of 1800 s−1 in a cone and plate device at 37°C. Activation of TGF-β1 was analyzed by ELISA and selectively confirmed using a cell-based plasminogen activator inhibitor 1 (PAI-1) luciferase reporter assay. TGF-β1 was maximally released within 5 min after stimulation of platelets with thrombin (80 ± 23 ng/ml; n=3), but only 0.2% was active. TGF-β1 activity increased slowly and progressively under shear, reaching a maximum of ∼5% of total TGF-β1 (4.1 ± 1.5 ng/ml) after 1 h. In sharp contrast, in two experiments conducted without shear, active TGF-β1 constituted 0.04 and 0.2% of total at 0 time and remained nearly the same (0.1 and 0.2% of total) after 2 h. Activation of TGF-β1 in serum under shear occurred more slowly, but also reached a maximum of ∼5% of total at 2 h (4.1 ± 1.3 ng/ml active; 76 ± 14 ng/ml total; n=6). Without shear at 0 time, active TGF-β1 constituted 0.02 and 0.06% of total and at 2 h it was still only 0.05 and 0.07% of total. To asses whether TGF-β1 becomes activated in vivo during thrombosis, we induced thrombi in the carotid arteries of C57/BL mice with ferric chloride (8%) for 3 min and then removed the platelet-rich thrombi that formed after 5 or 120 min. The arteries were excised (∼4 mm) and the thrombi were removed and dispersed in buffer (200 μl) on ice for 1 h. Total TGF-β1 recovered from 5 min thrombi was 3.4 and 4.8 ng/ml and total TGF-β1 recovered from 120 min thrombi was 3.7 and 0.7 ng/ml. Active TGF-β1 could be detected in thrombi after 5 min and constituted 1.7 ± 1.1% of the total TGF-β1 recovered (n=3). After 120 min, active TGF-β1 could also be detected in thrombi and it constituted 5.1 ± 3.0% of the total recovered (p=0.14 compared to 5 min value; n=3). In sharp contrast, only 0.05% of TGF-β1 released by thrombin from mouse platelets in vitro was active without stirring or shear (n=3). These data indicate that shear can dramatically enhance TGF-β1 activation after release from platelets. Moreover, TGF-β1 activation occurs in vivo during platelet-rich thrombus formation and thus platelets may be an important source of active TGF-β1 in cardiovascular disease and wound healing.

Download Full-text

Isorhamnetin Inhibits Liver Fibrosis by Reducing Autophagy and Inhibiting Extracellular Matrix Formation via the TGF-β1/Smad3 and TGF-β1/p38 MAPK Pathways

Mediators of Inflammation ◽

10.1155/2019/6175091 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14 ◽

Cited By ~ 3

Author(s):

Ning Liu ◽

Jiao Feng ◽

Xiya Lu ◽

Zhilu Yao ◽

Qing Liu ◽

...

Keyword(s):

Extracellular Matrix ◽

Liver Fibrosis ◽

Signaling Pathways ◽

P38 Mapk ◽

Transforming Growth Factor ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

Duct Ligation ◽

Mapk Signaling Pathways ◽

Tgf Β1

Objective. Liver fibrosis is a consequence of wound-healing responses to chronic liver insult and may progress to liver cirrhosis if not controlled. This study investigated the protection against liver fibrosis by isorhamnetin. Methods. Mouse models of hepatic fibrosis were established by intraperitoneal injection of carbon tetrachloride (CCl4) or bile duct ligation (BDL). Isorhamnetin 10 or 30 mg/kg was administered by gavage 5 days per week for 8 weeks in the CCl4 model and for 2 weeks in the BDL model. Protein and mRNA expressions were assayed by western blotting, immunohistochemistry, and quantitative real-time polymerase chain reaction. Results. Isorhamnetin significantly inhibited liver fibrosis in both models, inhibiting hepatic stellate cell (HSC) activation, extracellular matrix (ECM) deposition, and autophagy. The effects were associated with downregulation of transforming growth factor β1 (TGF-β1) mediation of Smad3 and p38 mitogen-activated protein kinase (MAPK) signaling pathways. Conclusion. Isorhamnetin protected against liver fibrosis by reducing ECM formation and autophagy via inhibition of TGF-β1-mediated Smad3 and p38 MAPK signaling pathways.

Download Full-text

Involvement of Smad7 in Inflammatory Diseases of the Gut and Colon Cancer

International Journal of Molecular Sciences ◽

10.3390/ijms22083922 ◽

2021 ◽

Vol 22 (8) ◽

pp. 3922

Author(s):

Edoardo Troncone ◽

Irene Marafini ◽

Carmine Stolfi ◽

Giovanni Monteleone

Keyword(s):

Transforming Growth Factor ◽

Intestinal Inflammation ◽

Inflammatory Responses ◽

Inflammatory Diseases ◽

Cell Types ◽

Transforming Growth Factor Β1 ◽

Cancer Prognosis ◽

Refractory Celiac Disease ◽

Bowel Diseases ◽

Tgf Β1

In physiological conditions, the human intestinal mucosa is massively infiltrated with various subsets of immune cells, the activity of which is tightly regulated by several counter-regulatory factors. One of these factors is transforming growth factor-β1 (TGF-β1), a cytokine produced by multiple cell types and targeting virtually all the intestinal mucosal cells. Binding of TGF-β1 to its receptors triggers Smad2/3 signaling, thus culminating in the attenuation/suppression of immune–inflammatory responses. In patients with Crohn’s disease and patients with ulcerative colitis, the major human inflammatory bowel diseases (IBD), and in mice with IBD-like colitis, there is defective TGF-β1/Smad signaling due to high levels of the intracellular inhibitor Smad7. Pharmacological inhibition of Smad7 restores TGF-β1 function, thereby reducing inflammatory pathways in patients with IBD and colitic mice. On the other hand, transgenic over-expression of Smad7 in T cells exacerbates colitis in various mouse models of IBD. Smad7 is also over-expressed in other inflammatory disorders of the gut, such as refractory celiac disease, necrotizing enterocolitis and cytomegalovirus-induced colitis, even though evidence is still scarce and mainly descriptive. Furthermore, Smad7 has been involved in colon carcinogenesis through complex and heterogeneous mechanisms, and Smad7 polymorphisms could influence cancer prognosis. In this article, we review the data about the expression and role of Smad7 in intestinal inflammation and cancer.

Download Full-text