scholarly journals Interdependence of HIF-1α and TGF-β/Smad3 signaling in normoxic and hypoxic renal epithelial cell collagen expression

2011 ◽  
Vol 300 (4) ◽  
pp. F898-F905 ◽  
Author(s):  
Rajit K. Basu ◽  
Susan Hubchak ◽  
Tomoko Hayashida ◽  
Constance E. Runyan ◽  
Paul T. Schumacker ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Renal Fibrosis ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Dominant Negative ◽  
Type I ◽  
Mrna Levels ◽  
Renal Epithelial Cell ◽  
Collagen Expression ◽  
Tgf Β1

Increasing evidence suggests that chronic kidney disease may develop following acute kidney injury and that this may be due, in part, to hypoxia-related phenomena. Hypoxia-inducible factor (HIF) is stabilized in hypoxic conditions and regulates multiple signaling pathways that could contribute to renal fibrosis. As transforming growth factor (TGF)-β is known to mediate renal fibrosis, we proposed a profibrotic role for cross talk between the TGF-β1 and HIF-1α signaling pathways in kidney cells. Hypoxic incubation increased HIF-1α protein expression in cultured human renal tubular epithelial cells and mouse embryonic fibroblasts. TGF-β1 treatment further increased HIF-1α expression in cells treated with hypoxia and also increased HIF-1α in normoxic conditions. TGF-β1 did not increase HIF-1α mRNA levels nor decrease the rate of protein degradation, suggesting that it enhances normoxic HIF-1α translation. TGF-β receptor (ALK5) kinase activity was required for increased HIF-1α expression in response to TGF-β1, but not to hypoxia. A dominant negative Smad3 decreased the TGF-β-stimulated reporter activity of a HIF-1α-sensitive hypoxia response element. Conversely, a dominant negative HIF-1α construct decreased Smad-binding element promoter activity in response to TGF-β. Finally, blocking HIF-1α transcription with a biochemical inhibitor, a dominant negative construct, or gene-specific knockdown decreased basal and TGF-β1-stimulated type I collagen expression, while HIF-1α overexpression increased both. Taken together, our data demonstrate cooperation in signaling between Smad3 and HIF-1α and suggest a new paradigm in which HIF-1α is necessary for normoxic, TGF-β1-stimulated renal cell fibrogenesis.

Upregulation of type I collagen by TGF-β in mesangial cells is blocked by PPARγ activation

2002 ◽  
Vol 282 (4) ◽  
pp. F639-F648 ◽  
Author(s):  
Feng Zheng ◽  
Alessia Fornoni ◽  
Sharon J. Elliot ◽  
Youfei Guan ◽  
Matthew D. Breyer ◽  
...  
Keyword(s):  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Mesangial Cells ◽  
Dominant Negative ◽  
Peroxisome Proliferator ◽  
Type I ◽  
Collagen Mrna ◽  
Collagen Expression ◽  
Pparγ Agonist ◽  
Pparγ Expression

We found that peroxisome proliferator-activated receptor-γ (PPARγ) mRNA was reduced by 77% in glomeruli of diabetic mice. Because mesangial cells play an important role in diabetic nephropathy, we examined regulation of type I collagen expression by PPARγ and transforming growth factor-β1 (TGF-β1) in mouse mesangial cells in the presence of 6 and 25 mM glucose. Mesangial cells contained functionally active PPARγ. Exposure to 25 mM glucose resulted in reduced PPARγ expression and transcriptional activity, accompanied by increased type I collagen expression. Restoration of PPARγ activity to normal levels in cells cultured in 25 mM glucose, by transfection with a PPARγ expression construct and treatment with the PPARγ agonist troglitazone, returned type I collagen levels toward normal values. Activation of PPARγ by troglitazone also decreased type I collagen mRNA and blocked TGF-β1-mediated upregulation of type I collagen mRNA and protein. Moreover, PPARγ activation suppressed basal and activated TGF-β1 responses in mesangial cells. This action was blocked by transfection of cells with a dominant-negative PPARγ construct. In summary, PPARγ suppresses the increased type I collagen mRNA and protein expression mediated by TGF-β1 in mesangial cells.

scholarly journals Hypoxia-inducible factor-2α and TGF-β signaling interact to promote normoxic glomerular fibrogenesis

2013 ◽  
Vol 305 (9) ◽  
pp. F1323-F1331 ◽  
Author(s):  
Christian Hanna ◽  
Susan C. Hubchak ◽  
Xiaoyan Liang ◽  
Benaya Rozen-Zvi ◽  
Paul T. Schumacker ◽  
...  
Keyword(s):  
Target Genes ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Mesangial Cells ◽  
In Vivo Studies ◽  
Type I ◽  
Mrna Levels ◽  
Α Subunit ◽  
Renal Tubular Cells ◽  
Tgf Β1

Hypoxia-inducible factors (HIFs) are transcription factors consisting of an oxygen-sensitive α-subunit binding to a stable β-subunit. HIFs regulate multiple signaling pathways that could contribute to fibrogenesis, supporting their potential role in hypoxia-mediated renal fibrosis. We previously reported that HIF-1 is upregulated and required for transforming growth factor (TGF)-β induction of collagen in renal tubular cells. Here, we performed in vitro and in vivo studies of potential glomerular crosstalk between TGF-β and normoxic HIF signaling. HIF-α has two major isoforms, HIF-1α and HIF-2α with different target gene sets. In cultured human mesangial cells, TGF-β1 treatment increased both HIF-1α and HIF-2α expression in normoxia. TGF-β1 did not increase HIF-1α/2α mRNA levels nor decrease the rate of protein degradation, suggesting that it enhances HIF-1α/2α expression through translation. TGF-β receptor (ALK5) kinase activity was required for increased, TGF-β-stimulated HIF-α expression in response to TGF-β, and inhibiting PI3-kinase markedly decreased HIF-α expression. Blocking HIF-1α/2α expression using siRNA decreased basal and TGF-β1-stimulated type I collagen expression, while overexpressing nondegradable HIF-α increased the collagen response, with HIF-2α being significantly more effective than HIF-1α. In adriamycin-induced mouse glomerulosclerosis, HIF-2α target genes were upregulated in sclerosing glomeruli. Taken together, our data demonstrate potential signaling interaction between TGF-β and HIFs to promote renal fibrogenesis in normoxia and suggest that the HIF-2α isoform is more important during glomerulosclerosis.

scholarly journals Red-COLA1: a human fibroblast reporter cell line for type I collagen transcription

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hui Hui Wong ◽  
Sze Hwee Seet ◽  
Charles C. Bascom ◽  
Robert J. Isfort ◽  
Frederic Bard
Keyword(s):  
Cell Line ◽  
Transforming Growth Factor Beta ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Type I ◽  
Reporter Cell Line ◽  
Reporter Cell ◽  
Reporter System ◽  
Collagen Expression ◽  
Tgf Β1

AbstractType I collagen is a key protein of most connective tissue and its up-regulation is required for wound healing but is also involved in fibrosis. Control of expression of this collagen remains poorly understood apart from Transforming Growth Factor beta (TGF-β1)-mediated induction. To generate a sensitive, practical, robust, image-based high-throughput-compatible reporter system, we genetically inserted a short-lived fluorescence reporter downstream of the endogenous type I collagen (COL1A1) promoter in skin fibroblasts. Using a variety of controls, we demonstrate that the cell line faithfully reports changes in type I collagen expression with at least threefold enhanced sensitivity compared to endogenous collagen monitoring. We use this assay to test the potency of anti-fibrotic compounds and screen siRNAs for regulators of TGF-β1-induced type I collagen expression. We propose our reporter cell line, Red-COLA1, as a new efficient tool to study type I collagen transcriptional regulation.

scholarly journals A Human Cellular Model for Colorectal Anastomotic Repair: The Effect of Localization and Transforming Growth Factor-β1 Treatment on Collagen Deposition and Biomarkers

2021 ◽  
Vol 22 (4) ◽  
pp. 1616
Author(s):  
Ceylan Türlü ◽  
Nicholas Willumsen ◽  
Debora Marando ◽  
Peter Schjerling ◽  
Edyta Biskup ◽  
...  
Keyword(s):  
Growth Factor ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Type I ◽  
Mrna Levels ◽  
Cellular Model ◽  
Collagen Deposition ◽  
Total Collagen ◽  
Tgf Β1

Anastomotic leakage (AL) is a devastating complication after colorectal surgery, possibly due to the loss of stabilizing collagen fibers in the submucosa. Our aim was to assess the formation of collagen in the colon versus the rectum with or without transforming growth factor (TGF)-β1 exposure in a human cellular model of colorectal repair. Primary fibroblasts were isolated by an explant procedure from clinically resected tissue rings during anastomosis construction in 19 consecutive colorectal patients who underwent laparoscopy. The cells, identified as fibroblasts by morphologic characteristics and flow cytometry analysis (CD90+), were cultured for 8 days and in 12 patients in the presence of 1 ng/mL TGF-β1. Total collagen deposition was measured colorimetrically after Sirius red staining of fixed cell layers, and type I, III, and VI collagen biosynthesis and degradation were specifically determined by the biomarkers PINP, PRO-C3, PRO-C6, and C3M in conditioned media by competitive enzyme-linked immunosorbent assays. Total collagen deposition by fibroblasts from the colon and rectum did not significantly differ. TGF-β1 treatment increased PINP, PRO-C6, and total collagen deposition. Mechanistically, TGF-β1 treatment increased COL1A1 and ACTA2 (encoding α-smooth muscle actin), and decreased COL6A1 and MMP2 mRNA levels in colorectal fibroblasts. In conclusion, we found no effect of anatomic localization on collagen production by fibroblasts derived from the large intestine. TGF-β1 represents a potential therapeutic agent for the prevention of AL by increasing type I collagen synthesis and collagen deposition.

Abstract 14664: Reduced Activin Like Kinase 1 Activity Promotes Cardiac Fibrosis in Heart Failure

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Kevin Morine ◽  
Vikram Paruchuri ◽  
Xiaoying Qiao ◽  
Emily Mackey ◽  
Mark Aronovitz ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Remodeling ◽  
Cardiac Fibrosis ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Left Ventricular ◽  
Lv Function ◽  
Type I ◽  
Mrna Levels ◽  
Protein Levels

Introduction: Activin receptor like kinase 1 (ALK1) mediates signaling via transforming growth factor beta-1 (TGFb1), a pro-fibrogenic cytokine. No studies have defined a role for ALK1 in heart failure. We tested the hypothesis that reduced ALK1 expression promotes maladaptive cardiac remodeling in heart failure. Methods and Results: ALK1 mRNA expression was quantified by RT-PCR in left ventricular (LV) tissue from patients with end-stage heart failure and compared to control LV tissue obtained from the National Disease Research Interchange (n=8/group). Compared to controls, LV ALK1 mRNA levels were reduced by 85% in patients with heart failure. Next, using an siRNA approach, we tested whether reduced ALK1 levels promote TGFb1-mediated collagen production in human cardiac fibroblasts. Treatment with an ALK1 siRNA reduced ALK1 mRNA levels by 75%. Compared to control, TGFb1-mediated Type I collagen and pSmad-3 protein levels were 2.5-fold and 1.7-fold higher, respectively, after ALK1 depletion. To explore a role for ALK1 in heart failure, ALK1 haploinsufficient (ALK1) and wild-type mice (WT; n=8/group) were studied 2 weeks after thoracic aortic constriction (TAC). Compared to WT, baseline LV ALK1 mRNA levels were 50% lower in ALK1 mice. Both LV and lung weights were higher in ALK1 mice after TAC. Cardiomyocyte area and LV mRNA levels of BNP, RCAN, and b-MHC were increased similarly, while SERCa levels were reduced in both ALK1 and WT mice after TAC. Compared to WT, LV fibrosis (Figure) and Type 1 Collagen mRNA and protein levels were higher among ALK1 mice. Compared to WT, LV fractional shortening (48±12 vs 26±10%, p=0.01) and survival (Figure) were lower in ALK1 mice after TAC. Conclusions: Reduced LV expression of ALK1 is associated with advanced heart failure in humans and promotes early mortality, impaired LV function, and cardiac fibrosis in a murine model of heart failure. Further studies examining the role of ALK1 and ALK1 inhibitors on cardiac remodeling are required.

scholarly journals Adhesion to type I collagen fibrous gels induces E- to N-cadherin switching without other EMT-related phenotypes in lung carcinoma cell A549

2020 ◽  
Author(s):  
Hitomi Fujisaki ◽  
Sugiko Futaki ◽  
Masashi Yamada ◽  
Kiyotoshi Sekiguchi ◽  
Toshihiko Hayashi ◽  
...  
Keyword(s):  
Single Cell ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
A549 Cells ◽  
Type I ◽  
Mesenchymal Transition ◽  
Cell Behaviors ◽  
Tgf Β1 ◽  
Cells Cultured ◽  
Cell Cell

AbstractIn culture system, environmental factors, such as increasing exogenous growth factors and adhesion to type I collagen (Col-I) induce epithelial-to-mesenchymal transition (EMT) in cells. Col-I molecules maintain a non-fibril form under acidic conditions, and they reassemble into fibrils under physiological conditions. Col-I fibrils often assemble to form three-dimensional gels. The gels and non-gel-form of Col-I can be utilized as culture substrates and different gel-forming state often elicit different cell behaviors. However, gel-form dependent effects on cell behaviors, including EMT induction, remain unclear. EMT induction in lung cancer cell line A549 has been reported via adhesion to Col-I but the effects of gel form dependency are unelucidated. This study investigated the changes in EMT-related behaviors in A549 cells cultured on Col-I gels.We examined cell morphology, proliferation, single-cell migration and expression of EMT-related features in A549 cells cultured on gels or non-gel form of Col-I and non-treated dish with or without transforming growth factor (TGF)-β1. On Col-I gels, some cells kept cell–cell contacts and formed clusters, others maintained single-cell form. In cell–cell contact regions, E-cadherin expression was downregulated, whereas that of N-cadherin was upregulated. Vimentin and integrins α2 and β1 expression were not increased. In TGF-β1-treated A549 cells, cadherin switched from E- to N-cadherin. Their morphology changed to a mesenchymal form and cells scattered with no cluster formation. Vimentin, integrins α2 and β1 expression were upregulated. Thus, we concluded that culture on Col-I fibrous gels induced E- to N-cadherin switching without other EMT-related phenotypes in A549 cells.

scholarly journals Transplantation of Telocytes Attenuates Unilateral Ureter Obstruction-Induced Renal Fibrosis in Rats

2018 ◽  
Vol 46 (5) ◽  
pp. 2056-2071 ◽  
Author(s):  
Long Zheng ◽  
Long Li ◽  
Guisheng Qi ◽  
Mushuang Hu ◽  
Chao Hu ◽  
...  
Keyword(s):  
Growth Factor ◽  
Protective Effect ◽  
Renal Fibrosis ◽  
Transforming Growth Factor ◽  
Kidney Tissue ◽  
Collagen I ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mrna Levels ◽  
Mesenchymal Transition ◽  
Tgf Β1

Background/Aims: Previous studies imply that telocytes may have a protective effect on fibrosis in various organs, including the liver, colon, and heart. The effect of telocytes on renal fibrosis remains unknown. Herein, this study was designed to investigate the effect of telocytes on renal fibrosis and the potential mechanisms involved. Methods: In a unilateral ureteral obstruction (UUO)-induced renal fibrosis model, telocytes were injected via the tail vein every other day for 10 days. The degree of renal damage and fibrosis was determined using histological assessment. The expression of collagen I, fibronectin, epithelial-mesenchymal transition markers, and Smad2/3 phosphorylation was examined by western blot analyses. Real-time PCR and enzyme-linked immunosorbent assay were performed in vivo to detect the levels of transforming growth factor (TGF)-β1 and various growth factors. Results: Telocytes attenuated renal fibrosis, as evidenced by reduced interstitial collagen accumulation, decreased expression of fibronectin and collagen I, upregulation of E-cadherin, and downregulation of α-smooth muscle actin. Furthermore, telocytes decreased serum TGF-β1 levels, suppressed Smad2/3 phosphorylation, and increased the expression of hepatocyte growth factor (HGF) in rat kidney tissue following UUO. Blockage of HGF counteracted the protective effect of telocytes on UUO-treated kidneys. Through the detection of HGF mRNA levels in vitro, we found that telocytes had no effect on HGF expression compared with renal fibroblasts. Conclusion: Telocytes attenuated UUO-induced renal fibrosis in rats, likely through enhancing the expression of HGF in an indirect manner.

scholarly journals Fucoxanthin Inhibits Myofibroblast Differentiation and Extracellular Matrix Production in Nasal Polyp-Derived Fibroblasts via Modulation of Smad-Dependent and Smad-Independent Signaling Pathways

Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 323 ◽  
Author(s):  
Hyun Jung ◽  
Dae-Sung Lee ◽  
Seong Park ◽  
Jung Choi ◽  
Won-Kyo Jung ◽  
...  
Keyword(s):  
Western Blot ◽  
Signaling Pathways ◽  
Nasal Polyp ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Type I ◽  
Molecular Signaling ◽  
Tgf Β1

Nasal polyps (NPs) are a multifactorial disorder associated with a chronic inflammatory state of the nasal mucosa. Fucoxanthin (Fx) is a characteristic orange carotenoid obtained from brown algae and has diverse immunological properties. The present study investigated whether Fx inhibits fibrosis-related effects in nasal polyp-derived fibroblasts (NPDFs) and elucidated the molecular signaling pathways involved. The production of collagen type I (Col-1) was investigated in NP tissue via immunohistochemistry and western blot analysis. NPDFs were treated with transforming growth factor (TGF)-β1 (1 ng/mL) in the presence or absence of Fx (5–30 µM). The levels of α-smooth muscle actin (α-SMA), Col-1, and phosphorylated (p)-Smad 2/3, signal protein-1 (SP-1), MAPKs (mitogen-activated protein kinases), and Akt were measured by western blot analysis. The expression of Col-1 was detected in NP tissues. TGF-β1 stimulated the production of α-SMA and Col-1, and stimulated the contraction of collagen gel. However, pretreatment with Fx attenuated these effects. Furthermore, these inhibitory effects were mediated through modulation of both Smad 2/3 and Akt/SP-1 signaling pathways in TGF-β1-induced NPDFs. The results from the present study suggest that Fx may be a novel anti-fibrotic agent for the treatment of NP formation.

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