Negative regulators of TGF-β1 signaling in renal fibrosis; pathological mechanisms and novel therapeutic opportunities

2021 ◽  
Vol 135 (2) ◽  
pp. 275-303
Author(s):  
Cody C. Gifford ◽  
Jiaqi Tang ◽  
Angelica Costello ◽  
Nidah S. Khakoo ◽  
Tri Q. Nguyen ◽  
...  

Abstract Elevated expression of the multifunctional cytokine transforming growth factor β1 (TGF-β1) is causatively linked to kidney fibrosis progression initiated by diabetic, hypertensive, obstructive, ischemic and toxin-induced injury. Therapeutically relevant approaches to directly target the TGF-β1 pathway (e.g., neutralizing antibodies against TGF-β1), however, remain elusive in humans. TGF-β1 signaling is subjected to extensive negative control at the level of TGF-β1 receptor, SMAD2/3 activation, complex assembly and promoter engagement due to its critical role in tissue homeostasis and numerous pathologies. Progressive kidney injury is accompanied by the deregulation (loss or gain of expression) of several negative regulators of the TGF-β1 signaling cascade by mechanisms involving protein and mRNA stability or epigenetic silencing, further amplifying TGF-β1/SMAD3 signaling and fibrosis. Expression of bone morphogenetic proteins 6 and 7 (BMP6/7), SMAD7, Sloan–Kettering Institute proto-oncogene (Ski) and Ski-related novel gene (SnoN), phosphate tensin homolog on chromosome 10 (PTEN), protein phosphatase magnesium/manganese dependent 1A (PPM1A) and Klotho are dramatically decreased in various nephropathies in animals and humans albeit with different kinetics while the expression of Smurf1/2 E3 ligases are increased. Such deregulations frequently initiate maladaptive renal repair including renal epithelial cell dedifferentiation and growth arrest, fibrotic factor (connective tissue growth factor (CTGF/CCN2), plasminogen activator inhibitor type-1 (PAI-1), TGF-β1) synthesis/secretion, fibroproliferative responses and inflammation. This review addresses how loss of these negative regulators of TGF-β1 pathway exacerbates renal lesion formation and discusses the therapeutic value in restoring the expression of these molecules in ameliorating fibrosis, thus, presenting novel approaches to suppress TGF-β1 hyperactivation during chronic kidney disease (CKD) progression.

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.


2021 ◽  
Vol 22 (5) ◽  
pp. 2580
Author(s):  
Won Kil Lee ◽  
Yeongyeong Kim ◽  
Heejin Jang ◽  
Joo Hye Sim ◽  
Hye Jin Choi ◽  
...  

Myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS) is one of the most refractory diseases in humans and is characterized by severe central fatigue accompanied with various symptoms that affect daily life, such as impaired memory, depression, and somatic pain. However, the etiology and pathophysiological mechanisms of CFS remain unknown. To investigate the pathophysiological role of transforming growth factor (TGF)-β1, we injected a cytokine into the lateral ventricle of a C57BL/6 mouse. The intracranial injection of TGF-β1 increased the immobility duration in a forced swimming test (FST) and time spent at the closed arm in elevated plus maze (EPM) analysis. The mice injected with TGF-β1 into their brain showed increased sensitivity to pain in a von Frey test, and had a decreased retention time on rotarod and latency time in a bright box in a passive avoidance test. In addition, the serum levels of muscle fatigue biomarkers, lactate dehydrogenase (LDH) and creatine kinase (CK), were significantly increased after administration of TGF-β1. Intracranial injection of TGF-β1 significantly reduced the production of tyrosine hydroxylase (TH) in the ventral tegmental area, accompanied by a decreased level of dopamine in the striatum. The suppression of TH expression by TGF-β1 was confirmed in the human neuroblastoma cell line, SH-SY5Y. These results, which show that TGF-β1 induced fatigue-like behaviors by suppressing dopamine production, suggest that TGF-β1 plays a critical role in the development of central fatigue and is, therefore, a potential therapeutic target of the disease.


2007 ◽  
Vol 204 (5) ◽  
pp. 1083-1093 ◽  
Author(s):  
Hye-Ryun Kang ◽  
Chun Geun Lee ◽  
Robert J. Homer ◽  
Jack A. Elias

Semaphorin (SEMA) 7A regulates neuronal and immune function. In these studies, we tested the hypothesis that SEMA 7A is also a critical regulator of tissue remodeling. These studies demonstrate that SEMA 7A and its receptors, plexin C1 and β1 integrins, are stimulated by transforming growth factor (TGF)-β1 in the murine lung. They also demonstrate that SEMA 7A plays a critical role in TGF-β1–induced fibrosis, myofibroblast hyperplasia, alveolar remodeling, and apoptosis. TGF-β1 stimulated SEMA 7A via a largely Smad 3–independent mechanism and stimulated SEMA 7A receptors, matrix proteins, CCN proteins, fibroblast growth factor 2, interleukin 13 receptor components, proteases, antiprotease, and apoptosis regulators via Smad 2/3–independent and SEMA 7A–dependent mechanisms. SEMA 7A also played an important role in the pathogenesis of bleomycin-induced pulmonary fibrosis. TGF-β1 and bleomycin also activated phosphatidylinositol 3-kinase (PI3K) and protein kinase B (PKB)/AKT via SEMA 7A–dependent mechanisms, and PKB/AKT inhibition diminished TGF-β1–induced fibrosis. These observations demonstrate that SEMA 7A and its receptors are induced by TGF-β1 and that SEMA 7A plays a central role in a PI3K/PKB/AKT-dependent pathway that contributes to TGF-β1–induced fibrosis and remodeling. They also demonstrate that the effects of SEMA 7A are not specific for transgenic TGF-β1, highlighting the importance of these findings for other fibrotic stimuli.


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.


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.


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.


2013 ◽  
Vol 25 (1) ◽  
pp. 162 ◽  
Author(s):  
Q. Meng ◽  
J. Hall ◽  
H. Rutigliano ◽  
X. Zhou ◽  
B. R. Sessions ◽  
...  

Transforming growth factor β1 (TGF-β1) has a potent profibrotic function and is central to signaling cascades involved in interstitial fibrosis, which plays a critical role in the pathobiology of cardiomyopathy and contributes to diastolic and systolic dysfunction. In addition, fibrotic remodeling is responsible for generation of re-entry circuits that promote arrhythmias (Bujak and Frangogiannis 2007 Cardiovasc. Res. 74, 184–195). Due to the small size of the heart, functional electrophysiology of transgenic mice is problematic. Large transgenic animal models have the potential to offer insights into conduction heterogeneity associated with fibrosis and the role of fibrosis in cardiovascular diseases. The goal of this study was to generate transgenic goats overexpressing an active form of TGFβ-1 under control of the cardiac-specific α-myosin heavy chain promoter (α-MHC). A pcDNA3.1DV5-MHC-TGF-β1cys33ser vector was constructed by subcloning the MHC-TGF-β1 fragment from the plasmid pUC-BM20-MHC-TGF-β1 (Nakajima et al. 2000 Circ. Res. 86, 571–579) into the pcDNA3.1D V5 vector. The Neon transfection system was used to electroporate primary goat fetal fibroblasts. After G418 selection and PCR screening, transgenic cells were used for SCNT. Oocytes were collected by slicing ovaries from an abattoir and matured in vitro in an incubator with 5% CO2 in air. Cumulus cells were removed at 21 to 23 h post-maturation. Oocytes were enucleated by aspirating the first polar body and nearby cytoplasm by micromanipulation in Hepes-buffered SOF medium with 10 µg of cytochalasin B mL–1. Transgenic somatic cells were individually inserted into the perivitelline space and fused with enucleated oocytes using double electrical pulses of 1.8 kV cm–1 (40 µs each). Reconstructed embryos were activated by ionomycin (5 min) and DMAP and cycloheximide (CHX) treatments. Cloned embryos were cultured in G1 medium for 12 to 60 h in vitro and then transferred into synchronized recipient females. Pregnancy was examined by ultrasonography on day 30 post-transfer. A total of 246 cloned embryos were transferred into 14 recipients that resulted in production of 7 kids. The pregnancy rate was higher in the group cultured for 12 h compared with those cultured 36 to 60 h [44.4% (n = 9) v. 20% (n = 5)]. The kidding rates per embryo transferred of these 2 groups were 3.8% (n = 156) and 1.1% (n = 90), respectively. The PCR results confirmed that all the clones were transgenic. Phenotype characterization [e.g. gene expression, electrocardiogram (ECG), and magnetic resonance imaging (MRI)] is underway. We demonstrated successful production of transgenic goat via SCNT. To our knowledge, this is the first transgenic goat model produced for cardiovascular research. This work was supported by the Utah Science Technology and Research Initiative, Utah Multidisciplinary Arrhythmia Consortium.


2013 ◽  
Vol 456 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Su Jin Lee ◽  
Jeong Han Kang ◽  
Soo Young Choi ◽  
Oh-Shin Kwon

In the present study, we demonstrated that PKCδ-stimulated RhoA/ROCK activation resulted in a reduction in PPM1A, thereby up-regulating Smad-dependent gene induction for extended periods. These findings indicated that PKCδ plays a critical role in TGF-β1-induced CTGF production in HepG2 cells.


2000 ◽  
Vol 192 (5) ◽  
pp. 695-704 ◽  
Author(s):  
Maria R. DiChiara ◽  
Jeanne Marie Kiely ◽  
Michael A. Gimbrone ◽  
Mu-En Lee ◽  
Mark A. Perrella ◽  
...  

Transforming growth factor (TGF)-β1 is a pleiotropic cytokine/growth factor that is thought to play a critical role in the modulation of inflammatory events. We demonstrate that exogenous TGF-β1 can inhibit the expression of the proinflammatory adhesion molecule, E-selectin, in vascular endothelium exposed to inflammatory stimuli both in vitro and in vivo. This inhibitory effect occurs at the level of transcription of the E-selectin gene and is dependent on the action of Smad proteins, a class of intracellular signaling proteins involved in mediating the cellular effects of TGF-β1. Furthermore, we demonstrate that these Smad-mediated effects in endothelial cells result from a novel competitive interaction between Smad proteins activated by TGF-β1 and nuclear factor κB (NFκB) proteins activated by inflammatory stimuli (such as cytokines or bacterial lipopolysaccharide) that is mediated by the transcriptional coactivator cyclic AMP response element–binding protein (CREB)-binding protein (CBP). Augmentation of the limited amount of CBP present in endothelial cells (via overexpression) or selective disruption of Smad–CBP interactions (via a dominant negative strategy) effectively antagonizes the ability of TGF-β1 to block proinflammatory E-selectin expression. These data thus demonstrate a novel mechanism of interaction between TGF-β1–regulated Smad proteins and NFκB proteins regulated by inflammatory stimuli in vascular endothelial cells. This type of signaling mechanism may play an important role in the immunomodulatory actions of this cytokine/growth factor in the cardiovascular system.


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.


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