scholarly journals Antenatal glucocorticoids counteract LPS changes in TGF-β pathway and caveolin-1 in ovine fetal lung

2013 ◽  
Vol 304 (6) ◽  
pp. L438-L444 ◽  
Author(s):  
Jennifer J. P. Collins ◽  
Steffen Kunzmann ◽  
Elke Kuypers ◽  
Matthew W. Kemp ◽  
Christian P. Speer ◽  
...  

Inflammation and antenatal glucocorticoids, the latter given to mothers at risk for preterm birth, affect lung development and may contribute to the development of bronchopulmonary dysplasia (BPD). The effects of the combined exposures on inflammation and antenatal glucocorticoids on transforming growth factor (TGF)-β signaling are unknown. TGF-β and its downstream mediators are implicated in the etiology of BPD. Therefore, we asked whether glucocorticoids altered intra-amniotic lipopolysaccharide (LPS) effects on TGF-β expression, its signaling molecule phosphorylated sma and mothers against decapentaplegic homolog 2 (pSmad2), and the downstream mediators connective tissue growth factor (CTGF) and caveolin-1 (Cav-1). Ovine singleton fetuses were randomized to receive either an intra-amniotic injection of LPS and/or maternal betamethasone (BTM) intramuscularly 7 and/or 14 days before delivery at 120 days gestational age (GA; term = 150 days GA). Saline was used for controls. Protein levels of TGF-β1 and -β2 were measured by ELISA. Smad2 phosphorylation was assessed by immunohistochemistry and Western blot. CTGF and Cav-1 mRNA and protein levels were determined by RT-PCR and Western blot. Free TGF-β1 and -β2 and total TGF-β1 levels were unchanged after LPS and/or BTM exposure, although total TGF-β2 increased in animals exposed to BTM 7 days before LPS. pSmad2 immunostaining increased 7 days after LPS exposure although pSmad2 protein expression did not increase. Similarly, CTGF mRNA and protein levels increased 7 days after LPS exposure as Cav-1 mRNA and protein levels decreased. BTM exposure before LPS prevented CTGF induction and Cav-1 downregulation. This study demonstrated that the intrauterine inflammation-induced TGF-β signaling can be inhibited by antenatal glucocorticoids in fetal lungs.

2021 ◽  
Vol 22 (6) ◽  
pp. 2952
Author(s):  
Tzu-Yu Hou ◽  
Shi-Bei Wu ◽  
Hui-Chuan Kau ◽  
Chieh-Chih Tsai

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.


2020 ◽  
Vol 34 ◽  
pp. 205873842092391 ◽  
Author(s):  
Min-na Dong ◽  
Yun Xiao ◽  
Yun-fei Li ◽  
Dong-mei Wang ◽  
Ya-ping Qu ◽  
...  

Intravenous Xuebijing (XBJ) therapy suppresses paraquat (PQ)-induced pulmonary fibrosis. However, the mechanism underlying this suppression remains unknown. This work aimed to analyze the miR-140-5p-induced effects of XBJ injection on PQ-induced pulmonary fibrosis in mice. The mice were arbitrarily assigned to four groups. The model group was administered with PQ only. The PQ treatment group was administered with PQ and XBJ. The control group was administered with saline only. The control treatment group was administered with XBJ only. The miR-140-5p and miR-140-5p knockout animal models were overexpressed. The gene expression levels of miR-140-5p, transglutaminase-2 (TG2), β-catenin, Wnt-1, connective tissue growth factor (CTGF), mothers against decapentaplegic homolog (Smad), and transforming growth factor-β1 (TGF-β1) in the lungs were assayed with quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot analysis. The levels of TGF-β1, CTGF, and matrix metalloproteinase-9 (MMP-9) in the bronchoalveolar lavage fluid were assessed by enzyme-linked immunosorbent assay (ELISA). Hydroxyproline (Hyp) levels and pulmonary fibrosis were also scored. After 14 days of PQ induction of pulmonary fibrosis, AdCMV-miR-140-5p, and XBJ upregulated miR-140-5p expression; blocked the expressions of TG2, Wnt-1, and β-catenin; and decreased p-Smad2, p-Smad3, CTGF, MMP-9, and TGF-β1 expressions. In addition, Hyp and pulmonary fibrosis scores in XBJ-treated mice decreased. Histological results confirmed that PQ-induced pulmonary fibrosis in XBJ-treated lungs was attenuated. TG2 expression and the Wnt-1/β-catenin signaling pathway were suppressed by the elevated levels of miR-140-5p expression. This inhibition was pivotal in the protective effect of XBJ against PQ-induced pulmonary fibrosis. Thus, XBJ efficiently alleviated PQ-induced pulmonary fibrosis in mice.


2005 ◽  
Vol 93 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Jie Mei ◽  
Ruo-Jun Xu

It is well known that early weaning causes marked changes in intestinal structure and function, and transforming growth factor-β (TGF-β) is believed to play an important regulatory role in post-weaning adaptation of the small intestine. The present study examined the distribution and expression intensity of TGF-β in the small intestinal mucosa of pre- and post-weaning pigs using a specific immunostaining technique and Western blot analysis. The level of TGF-β in the intestinal mucosa, as estimated by Western blot analysis, did not change significantly during weaning. However, when examined by the immunostaining technique, TGF-β1 (one of the TGF-β isoforms dominantly expressed in the tissue) at the intestinal villus epithelium, particularly at the apical membrane of the epithelium, decreased significantly 4 d after weaning, while the staining intensity increased significantly at the intestinal crypts compared with that in pre-weaning pigs. These changes were transient, with the immunostaining intensity for TGF-β1 at the intestinal villi and the crypts returning to the pre-weaning level by 8 d post-weaning. The transient decrease in TGF-β1 level at the intestinal villus epithelium was associated with obvious intestinal villus atrophy and marked reduction of mucosal digestive enzyme activities. Furthermore, the number of leucocytes staining positively for TGF-β1 increased significantly in the pig intestinal lamina propria 4 d after weaning. These findings strongly suggest that TGF-β plays an important role in the post-weaning adaptation process in the intestine of the pig.


2011 ◽  
Vol 441 (1) ◽  
pp. 499-510 ◽  
Author(s):  
Helen C. O'Donovan ◽  
Fionnuala Hickey ◽  
Derek P. Brazil ◽  
David H. Kavanagh ◽  
Noelynn Oliver ◽  
...  

The critical involvement of TGF-β1 (transforming growth factor-β1) in DN (diabetic nephropathy) is well established. However, the role of CTGF (connective tissue growth factor) in regulating the complex interplay of TGF-β1 signalling networks is poorly understood. The purpose of the present study was to investigate co-operative signalling between CTGF and TGF-β1 and its physiological significance. CTGF was determined to bind directly to the TβRIII (TGF-β type III receptor) and antagonize TGF-β1-induced Smad phosphorylation and transcriptional responses via its N-terminal half. Furthermore, TGF-β1 binding to its receptor was inhibited by CTGF. A consequent shift towards non-canonical TGF-β1 signalling and expression of a unique profile of differentially regulated genes was observed in CTGF/TGF-β1-treated mesangial cells. Decreased levels of Smad2/3 phosphorylation were evident in STZ (streptozotocin)-induced diabetic mice, concomitant with increased levels of CTGF. Knockdown of TβRIII restored TGF-β1-mediated Smad signalling and cell contractility, suggesting that TβRIII is key for CTGF-mediated regulation of TGF-β1. Comparison of gene expression profiles from CTGF/TGF-β1-treated mesangial cells and human renal biopsy material with histological diagnosis of DN revealed significant correlation among gene clusters. In summary, mesangial cell responses to TGF-β1 are regulated by cross-talk with CTGF, emphasizing the potential utility of targeting CTGF in DN.


2016 ◽  
Vol 40 (1-2) ◽  
pp. 27-38 ◽  
Author(s):  
Johanna Ábrigo ◽  
Felipe Simon ◽  
Daniel Cabrera ◽  
Claudio Cabello-Verrugio

Background: Transforming growth factor type beta 1 (TGF-β1) produces skeletal muscle atrophy. Angiotensin-(1-7) (Ang-(1-7)), through the Mas receptor, prevents the skeletal muscle atrophy induced by sepsis, immobilization, or angiotensin II (Ang-II). However, the effect of Ang-(1-7) on muscle wasting induced by TGF-β1 is unknown. Aim: To evaluate whether Ang-(1-7)/Mas receptor axis could prevent the skeletal muscle atrophy induced by TGF-β1. Methods: This study assessed the atrophic effect of TGF-β1 in C2C12 myotubes and mice in absence or presence of Ang-(1-7), and the receptor participation using A779, an antagonist of the Mas receptor. The levels of myosin heavy chain (MHC), polyubiquitination, and MuRF-1 were detected by western blot. Myotube diameter was also evaluated. In vivo analysis included the muscle strength, fibre diameter, MHC and MuRF-1 levels by western blot, and ROS levels by DCF probe detection. Results: The results showed that Ang-(1-7) prevented the increase in MuRF-1 and polyubiquitined protein levels, the decrease of MHC levels, the myotubes/fibre diameter diminution, and the increased production of reactive oxygen species (ROS) induced by TGF-β1. Utilizing A779 inhibited the anti-atrophic effect of Ang-(1-7). Conclusion: The preventive effect of Ang-(1-7) on skeletal muscle atrophy induced by TGF-β1 is produced through inhibition of ROS production and proteasomal degradation of MHC.


2005 ◽  
Vol 288 (3) ◽  
pp. F483-F492 ◽  
Author(s):  
Yan Tan ◽  
Bing Wang ◽  
Joo-Seob Keum ◽  
Ayad A. Jaffa

In diabetes, mesangial cell proliferation and extracellular matrix expansion are critical components in the development of glomerulosclerosis. We reported that diabetes alters the activity of the kallikrein-kinin system and that these alterations contribute to the development of diabetic nephropathy. The present study examined the influence of streptozotocin-induced diabetes on the renal expression of bradykinin (BK) B2 receptors (B2KR), connective tissue growth factor (CTGF), transforming growth factor-β (TGF-β), and TGF-β type II receptor (TGF-βRII) and assessed the signaling mechanisms through which B2KR activation may promote glomerular injury. Eight weeks after the induction of diabetes, renal mRNA levels of B2KR, CTGF, and TGF-β as well as protein levels of CTGF and TGF-βRII were measured in control (C), diabetic (D), and insulin-treated diabetic (D+I) rats. Renal B2KR and TGF-β mRNA levels expressed relative to β-actin mRNA levels and CTGF and TGF-βRII protein levels were significantly increased in D and D+I rats compared with C rats ( P < 0.03, n = 5). To assess the contribution of B2KR activation on modulating the expression of CTGF, TGF-βRII, and collagen I, mesangial cells (MC) were treated with BK (10−8 M) for 24 h and CTGF and TGF-βRII protein levels were measured by Western blots and collagen I mRNA levels were measured by RT-PCR. A two- to threefold increase in CTGF and TGF-βRII protein levels was observed in response to BK stimulation ( P < 0.001, n = 6). In addition, a marked increase in collagen I mRNA levels was observed in response to BK stimulation. Treatment of MC with BK (10−8 M) for 5 min significantly increased the tyrosine phosphorylation of p60src kinase and of p42/p44 MAPK ( P < 0.05, n = 4). Inhibition of src kinase by PP1 (10 μM) inhibited the increase in p42/p44 MAPK activation in response to BK. Finally, to determine whether BK stimulates CTGF, TGF-βRII, and collagen I expression via activation of MAPK pathways, MC were pretreated with an inhibitor of p42/p44 MAPK (PD-98059) for 45 min, followed by BK (10−8 M) stimulation for 24 h. Selective inhibition of p42/p44 MAPK significantly inhibited the BK-induced increase in CTGF, TGF-βRII, and collagen I levels. These findings are the first to demonstrate that BK regulates the expression of CTGF, TGF-βRII, and collagen I in MC and provide a mechanistic pathway through which B2KR activation may contribute to the development of diabetic nephropathy.


2006 ◽  
Vol 18 (6) ◽  
pp. 655 ◽  
Author(s):  
Megan J. Wallace ◽  
Alison M. Thiel ◽  
Andrea M. Lines ◽  
Graeme R. Polglase ◽  
Foula Sozo ◽  
...  

Increased fetal lung expansion induces lung growth, cell differentiation and extracellular matrix remodelling, although the mechanisms involved are unknown. Platelet-derived growth factor (PDGF)-B, vascular endothelial growth factor (VEGF) and insulin-like growth factor (IGF)-II are mitogens activating the mitogen-activated protein kinase (MAPK) pathway, whereas transforming growth factor (TGF)-β1 induces differentiation and extracellular matrix remodelling. In the present study, we investigated the mRNA levels of PDGF-B, VEGF, IGF-II and TGF-β1, as well as active MAPK levels, during increased fetal lung expansion induced by tracheal obstruction (TO) in sheep for 0 (controls), 36 h or 2, 4, or 10 days (n = 5 in each group). The 3.7-kb VEGF transcript increased by 30% (P < 0.05) at 36 h TO. The expression of PDGF-B decreased by approximately 25% (P < 0.01) at 2–10 days TO. In contrast, TGF-β1 mRNA increased by 96% (P < 0.05) at 10 days TO, when bioactive TGF-β1 decreased by 55% (P < 0.05). Insulin-like growth factor-II mRNA tended to increase at 10 days TO (37% above controls; P = 0.07), whereas mRNA for its receptor, IGF1R, was reduced by TO. There was no change in active MAPK levels preceding or at the time of a TO-induced 800% increase in cell proliferation. We conclude that VEGF is likely to promote expansion-induced endothelial cell proliferation, but the mechanisms underlying expansion-induced proliferation of fibroblasts and alveolar epithelial cells are unlikely to be mediated by increases in PDGF-B or IGF-II expression or activation of the MAPK pathway.


2005 ◽  
Vol 288 (2) ◽  
pp. C435-C442 ◽  
Author(s):  
XiuXia Zhou ◽  
John B. Trudeau ◽  
Kathryn J. Schoonover ◽  
Jessica I. Lundin ◽  
Steve M. Barnes ◽  
...  

Tissue inhibitor of metalloproteinase (TIMP)-1 is a potent inhibitor of activated matrix metalloproteinases (MMPs) such as gelatinases and collagenases. TIMP-1 is induced by transforming growth factor-β1 (TGF-β1), but details regarding signaling pathways remain unclear. T-helper-2 cytokines also have profibrotic properties and can interact with TGF-β. In the present study, we examined the effects of interleukin (IL)-13 (2,500 pM) on TGF-β1 (200 pM)-induced expression of TIMP-1 mRNA and protein in primary human airway fibroblasts obtained from 57 human subjects. IL-13 alone had no effect on TIMP-1 mRNA or protein expression. However, IL-13 synergistically augmented TGF-β1-induced TIMP-1 mRNA and protein expression ( P < 0.001 vs. TGF-β1 alone). The upregulation of TIMP-1 by the combination of TGF-β1 and IL-13 involved increased transcription, with little effect on mRNA stabilization. Initial exploration of the pathways leading to the synergy determined that activation of the phosphatidylinositol 3-kinase (PI3K)-Akt pathway by IL-13 may have a negative effect on TIMP-1 production. The specific PI3K inhibitor LY-294002 in the presence of TGF-β1, IL-13, or the combination of the two caused significant increases in TIMP-1 mRNA expression, while LY-294002 increased TIMP-1 protein levels in the presence of IL-13 alone. These results suggest that IL-13 augments TGF-β1-induced profibrotic responses at both the mRNA and protein levels. Although IL-13 induced activation of PI3K-Akt, the activation did not contribute to the synergy observed with TGF-β1 plus IL-13 in TIMP-1 expression and in fact may dampen it. The mechanisms behind the synergy remain to be determined.


2004 ◽  
Vol 286 (1) ◽  
pp. L189-L197 ◽  
Author(s):  
Emiko Ogawa ◽  
W. Mark Elliott ◽  
Fiona Hughes ◽  
Thomas J. Eichholtz ◽  
James C. Hogg ◽  
...  

Previous studies showed an association between latent adenoviral infection with expression of the adenoviral E1A gene and chronic obstructive pulmonary disease (COPD). The present study focuses on how the adenoviral E1A gene could alter expression of growth factors by human bronchial epithelial (HBE) cells. The data show that connective tissue growth factor (CTGF) and transforming growth factor (TGF)-β1 mRNA and protein expression were upregulated in E1A-positive HBE cells. Upregulation of CTGF in this in vitro model was independent of TGF-β secreted into the growth medium. Comparison of E1A-positive with E1A-negative HBE cells showed that both expressed cytokeratin but only E1A-positive cells expressed the mesenchymal markers vimentin and α-smooth muscle actin. We conclude that latent infection of epithelial cells by adenovirus E1A could contribute to airway remodeling in COPD by the viral E1A gene, inducing TGF-β1 and CTGF expression and shifting cells to a more mesenchymal phenotype.


2021 ◽  
Vol 22 (14) ◽  
pp. 7660
Author(s):  
Magdalena Schneider ◽  
Andrea E. Dillinger ◽  
Andreas Ohlmann ◽  
Renato V. Iozzo ◽  
Rudolf Fuchshofer

During the pathogenesis of glaucoma, optic nerve (ON) axons become continuously damaged at the optic nerve head (ONH). This often is associated with reactive astrocytes and increased transforming growth factor (TGF-β) 2 levels. In this study we tested the hypothesis if the presence or absence of decorin (DCN), a small leucine-rich proteoglycan and a natural inhibitor of several members of the TGF family, would affect the expression of the TGF-βs and connective tissue growth factor (CTGF/CCN2) in human ONH astrocytes and murine ON astrocytes. We found that DCN is present in the mouse ON and is expressed by human ONH and murine ON astrocytes. DCN expression and synthesis was significantly reduced after 24 h treatment with 3 nM CTGF/CCN2, while treatment with 4 pM TGF-β2 only reduced expression of DCN significantly. Conversely, DCN treatment significantly reduced the expression of TGF-β1, TGF-β2 and CTGF/CCN2 vis-a-vis untreated controls. Furthermore, DCN treatment significantly reduced expression of fibronectin (FN) and collagen IV (COL IV). Notably, combined treatment with DCN and triciribine, a small molecule inhibitor of protein kinase B (AKT), attenuated effects of DCN on CTGF/CCN2, TGF-β1, and TGF-β2 mRNA expression. We conclude (1) that DCN is an important regulator of TGF-β and CTGF/CCN2 expression in astrocytes of the ON and ONH, (2) that DCN thereby regulates the expression of extracellular matrix (ECM) components and (3) that DCN executes its negative regulatory effects on TGF-β and CTGF/CCN2 via the pAKT/AKT signaling pathway in ON astrocytes.


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