scholarly journals Glucosamine impedes transforming growth factor β1-mediated corneal fibroblast differentiation by targeting Krüppel-like factor 4

2019 ◽  
Vol 26 (1) ◽  
Author(s):  
Ying-Jen Chen ◽  
Shih-Ming Huang ◽  
Ming-Cheng Tai ◽  
Jiann-Torng Chen ◽  
Chang-Min Liang
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Disease Model ◽  
Immunoblot Analysis ◽  
Transforming Growth Factor Β1 ◽  
Myofibroblast Differentiation ◽  
Alpha Smooth Muscle Actin ◽  
Corneal Fibroblasts ◽  
Tgf Β1

Abstract Background Transforming growth factor (TGF) family members play important roles in the regulation of corneal integrity, and the pathogenesis of corneal fibrosis. Currently, there are no effective agents targeting TGF-β signaling to diminish corneal fibrosis. Glucosamine (GlcN), which is widely used in the treatment of osteoarthritis, abrogates the morphologic effects of TGF-β2 on retinal pigmented epithelial cells in a mouse disease model. Here, we sought to determine whether GlcN would exert beneficial effects against TGF-β1-induced corneal fibrosis. Methods In human corneal fibroblasts (HCFs) treated with GlcN, the expression of Krüppel-like factor 4 (KLF4) and its downstream signaling effects were determined in the presence and absence of TGF-β1 using immunoblot analysis. We further explored GlcN inhibition of fibroblast-to-myofibroblast differentiation via KLF4 siRNA. The effect of cycloheximide on KLF4 protein levels with or without GlcN administration was assessed to determine whether GlcN affects the stability of the KLF4 protein. Results In HCFs, GlcN induced the expression of KLF4, which regulated the maturation and maintenance of the ocular surface. GlcN partially suppressed the TGF-β1-induced expression of alpha-smooth muscle actin (α-SMA) and reduced the collagen contraction capacity in HCFs, suggesting a decrease in fibroblast-to-myofibroblast differentiation. This effect appeared to be mediated through suppression of Smad2 phosphorylation and ERK-dependent signaling. The levels of KLF4 mRNA were increased by GlcN and decreased by TGF-β1 and the TGF-β1-induced α-SMA mRNA expression was upregulated when the KLF4 gene was silenced. GlcN also appeared to stabilize the KLF4 protein, reducing its turnover in corneal fibroblasts. Conclusion These findings shed light on a novel mechanism by which GlcN suppresses TGF-β1-induced fibroblast-to-myofibroblast differentiation through the upregulation of KLF4 expression. Current strategies for treating corneal fibrosis were not effective. Elevating KLF4 levels through the use of GlcN might provide an effective alternative to alleviate the development and progression of corneal fibrosis.

α-Lipoic acid modulates liver fibrosis: A cross talk between TGF-β1, autophagy, and apoptosis

2019 ◽  
Vol 39 (4) ◽  
pp. 440-450 ◽  
Author(s):  
WH El-Maadawy ◽  
OA Hammam ◽  
SH Seif el-Din ◽  
NM El-Lakkany
Keyword(s):  
Growth Factor ◽  
Liver Fibrosis ◽  
Hepatic Fibrosis ◽  
Lipoic Acid ◽  
Messenger Rna ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Transforming Growth Factor Β1 ◽  
Alpha Smooth Muscle Actin ◽  
Tgf Β1

Autophagy and apoptosis are important players in the progression of hepatic fibrosis via activation of hepatic stellate cells (HSCs). Despite the recently depicted antifibrotic effects of alpha-lipoic acid (ALA), however, its modulatory effects on HSCs autophagy remain unverified. Our study aimed to elucidate the underlying antifibrotic mechanisms through which ALA mediates HSC autophagy and apoptosis. Liver fibrosis was induced via thioacetamide (TAA) intoxication in rats; TAA-intoxicated rats were treated with either silymarin or ALA. Effect of ALA on biochemical parameters and immunohistopathological examinations was measured and compared to silymarin. ALA restored normal hepatic architecture (S1 vs. S4), liver functions, hepatic glutathione, and transforming growth factor-β1 levels. ALA ameliorated hepatic levels of malondialdehyde, platelet-derived growth factor, tissue inhibitor metalloproteinases-1, hydroxyproline, and expression of alpha-smooth muscle actin. Moreover, ALA significantly reduced messenger RNA expression of LC3-II genes and triggered caspase-3 expression. Interestingly, ALA exhibited superior activities over silymarin regarding suppression of proliferation, activation and autophagy of HSCs, collagen deposition, and induction of HSCs apoptosis. In conclusion, treatment of TAA-intoxicated rats with ALA inhibited autophagy and induced apoptotic clearance of activated HSCs. Accordingly, this study provides mechanistic insights into the possible applicability of ALA in the treatment of hepatic fibrosis.

Systembiologie in der Ophthalmologie – innovative Wirkstoffidentifikation zur spezifischen Vermeidung postoperativer Fibrose

2019 ◽  
Vol 236 (12) ◽  
pp. 1428-1434
Author(s):  
Thomas Stahnke ◽  
Beata Gajda-Derylo ◽  
Oliver Stachs ◽  
Rudolf F. Guthoff ◽  
Anselm Jünemann ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Transforming Growth Factor Β1 ◽  
Connectivity Map ◽  
Alpha Smooth Muscle Actin ◽  
Next Generation Sequencing Ngs ◽  
Cluster Of Differentiation ◽  
Tgf Β1

Zusammenfassung Hintergrund Der Langzeiterfolg fistulierender Therapiekonzepte zur Behandlung des Glaukoms wird im Wesentlichen durch überschießende Vernarbungsreaktionen (Fibrose) limitiert. Zytostatika wie Mitomycin C können die Fibrose zwar verhindern, sind jedoch häufig mit Nebenwirkungen assoziiert. Spezifisch wirkende Antifibrotika sind derzeit nicht im klinischen Einsatz. Daher beschreibt diese Studie einen systembiologischen Ansatz, mit dem durch eine dedizierte Bioinformatik-Technologieplattform Wirkstoffe identifiziert und als Antifibrotikum repositioniert werden können. Material und Methoden Als Basis für den Wirkstoffidentifikationsprozess wurden differenzielle Genexpressionsdaten humaner Tenon-Fibroblasten (hTF) genutzt, die von unbehandelten hTF und von mit Transforming Growth Factor β1 (TGF-β1) stimulierten hTF („fibrotische Fibroblasten“) mittels Next-Generation Sequencing (NGS) erhoben wurden. Diese Daten wurden mit dem bioinformatischen Werkzeug „FocusHeuristics“ gefiltert. Im Vergleich mit der Connectivity-Map-Datenbank wurden der Fibrose entgegenwirkende Wirkstoffe identifiziert. Die Evaluierung eines potenziell erfolgversprechenden Wirkstoffs als Antifibrotikum wurde an hTF mittels indirekter Immunfluoreszenz in vitro durchgeführt. Ergebnisse Die Analyse der Genexpressionsdaten führte zur Identifikation mehrerer in fibrotische Prozesse involvierter Interaktionsnetzwerke von Genen bzw. Proteinen. Eines dieser Netzwerke beinhaltet das Zytokin Bone morphogenic Protein 6 (BMP6) sowie Interleukin 6 (IL6) und Fibroblast Growth Factor 1 (FGF1). Ein weiteres relevantes Netzwerk konnte rund um das CD34-Gen (CD34: Cluster of Differentiation 34) identifiziert werden. Der Vergleich dieser Daten mit denen der Connectivity Map ermöglichte die Identifikation eines entsprechend invers wirkenden Wirkstoffs. Dessen Evaluierung im fibrotischen Zellkulturmodell in vitro mittels indirekter Immunfluoreszenz führte zu einer deutlichen Expressionsreduktion der fibrotischen Markerproteine Fibronektin und Alpha-smooth Muscle Actin (α-SMA), womit die vorhergesagte antifibrotische Wirkung bestätigt werden konnte. Schlussfolgerung Systembiologische Ansätze können für die Identifikation von antifibrotischen Wirkstoffkandidaten zur Vermeidung postoperativer Fibrose genutzt werden und sollten sich über die Erfassung differenzieller Genexpressionsdaten weiterer okularer Zellen oder Gewebe auch auf andere ophthalmologische Anwendungsfelder transferieren lassen.

scholarly journals Regulation of Cellular Senescence Is Independent from Profibrotic Fibroblast-Deposited ECM

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1628
Author(s):  
Kaj E. C. Blokland ◽  
Habibie Habibie ◽  
Theo Borghuis ◽  
Greta J. Teitsma ◽  
Michael Schuliga ◽  
...  
Keyword(s):  
Growth Factor ◽  
Cellular Senescence ◽  
Transforming Growth Factor ◽  
Cell Function ◽  
Smooth Muscle Actin ◽  
Transforming Growth Factor Β1 ◽  
Tissue Growth ◽  
Alveolar Epithelial Cells ◽  
Lung Fibroblasts ◽  
Alpha Smooth Muscle Actin

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with poor survival. Age is a major risk factor, and both alveolar epithelial cells and lung fibroblasts in this disease exhibit features of cellular senescence, a hallmark of ageing. Accumulation of fibrotic extracellular matrix (ECM) is a core feature of IPF and is likely to affect cell function. We hypothesize that aberrant ECM deposition augments fibroblast senescence, creating a perpetuating cycle favouring disease progression. In this study, primary lung fibroblasts were cultured on control and IPF-derived ECM from fibroblasts pretreated with or without profibrotic and prosenescent stimuli, and markers of senescence, fibrosis-associated gene expression and secretion of cytokines were measured. Untreated ECM derived from control or IPF fibroblasts had no effect on the main marker of senescence p16Ink4a and p21Waf1/Cip1. However, the expression of alpha smooth muscle actin (ACTA2) and proteoglycan decorin (DCN) increased in response to IPF-derived ECM. Production of the proinflammatory cytokines C-X-C Motif Chemokine Ligand 8 (CXCL8) by lung fibroblasts was upregulated in response to senescent and profibrotic-derived ECM. Finally, the profibrotic cytokines transforming growth factor β1 (TGF-β1) and connective tissue growth factor (CTGF) were upregulated in response to both senescent- and profibrotic-derived ECM. In summary, ECM deposited by IPF fibroblasts does not induce cellular senescence, while there is upregulation of proinflammatory and profibrotic cytokines and differentiation into a myofibroblast phenotype in response to senescent- and profibrotic-derived ECM, which may contribute to progression of fibrosis in IPF.

scholarly journals FAK Inhibition Attenuates Corneal Fibroblast Differentiation In Vitro

Biomolecules ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1682
Author(s):  
Vincent Yeung ◽  
Sriniwas Sriram ◽  
Jennifer A. Tran ◽  
Xiaoqing Guo ◽  
Audrey E. K. Hutcheon ◽  
...  
Keyword(s):  
Wound Healing ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Myofibroblast Differentiation ◽  
Corneal Scarring ◽  
Corneal Fibroblast ◽  
Corneal Fibroblasts ◽  
Corneal Wound ◽  
Tgf Β1

Corneal fibrosis (or scarring) occurs in response to ocular trauma or infection, and by reducing corneal transparency, it can lead to visual impairment and blindness. Studies highlight important roles for transforming growth factor (TGF)-β1 and -β3 as modulators in corneal wound healing and fibrosis, leading to increased extracellular matrix (ECM) components and expression of α-smooth muscle actin (αSMA), a myofibroblast marker. In this study, human corneal fibroblasts (hCF) were cultured as a monolayer culture (2D) or on poly-transwell membranes to generate corneal stromal constructs (3D) that were treated with TGF-β1, TGF-β3, or TGF-β1 + FAK inhibitor (FAKi). Results show that hCF 3D constructs treated with TGF-β1 or TGF-β3 impart distinct effects on genes involved in wound healing and fibrosis—ITGAV, ITGB1, SRC and ACTA2. Notably, in the 3D construct model, TGF-β1 enhanced αSMA and focal adhesion kinase (FAK) protein expression, whereas TGF-β3 did not. In addition, in both the hCF 2D cell and 3D construct models, we found that TGF-β1 + FAKi attenuated TGF-β1-mediated myofibroblast differentiation, as shown by abrogated αSMA expression. This study concludes that FAK signaling is important for the onset of TGF-β1-mediated myofibroblast differentiation, and FAK inhibition may provide a novel beneficial therapeutic avenue to reduce corneal scarring.

scholarly journals Therapeutic Effects of an Inhibitor of Thioredoxin Reductase on Liver Fibrosis by Inhibiting the Transforming Growth Factor-β1/Smads Pathway

2021 ◽  
Vol 8 ◽  
Author(s):  
Wenxuan Jiao ◽  
Man Bai ◽  
Hanwei Yin ◽  
Jiayi Liu ◽  
Jing Sun ◽  
...  
Keyword(s):  
Growth Factor ◽  
Liver Fibrosis ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Thioredoxin Reductase ◽  
Transforming Growth Factor Β1 ◽  
Therapeutic Effects ◽  
Pathological State ◽  
Tgf Β1

Liver fibrosis is an important stage in the progression of liver injury into cirrhosis or even liver cancer. Hepatic stellate cells (HSCs) are induced by transforming growth factor-β1 (TGF-β1) to produce α-smooth muscle actin (α-SMA) and collagens in liver fibrosis. Butaselen (BS), which was previously synthesized by our group, is an organic selenium compound that exerts antioxidant and tumor cell apoptosis–promoting effects by inhibiting the thioredoxin (Trx)/thioredoxin reductase (TrxR) system. The aim of this study was to investigate the potential effects of BS on liver fibrosis and explore the underlying molecular mechanisms of its action. Liver fibrosis models were established using male BALB/c mice through intraperitoneal injection of CCl4. BS was administered orally once daily at a dose of 36, 90, or 180 mg/kg. Silymarin (Si), which is a drug used for patients with nonalcoholic fatty liver disease and nonalcoholic steatohepatitis, was administered at a dose of 30 mg/kg per day as a control. The action mechanisms of BS against liver fibrosis progression were examined in HSCs. The study revealed that the activity and expression levels of TrxR were elevated in the mouse liver and serum after CCl4-induced liver fibrosis. Oral administration of BS relieved the pathological state of mice with liver fibrosis, showing significant therapeutic effects against liver fibrosis. Moreover, BS not only induced HSC apoptosis but also inhibited the production of α-SMA and collagens by HSCs by downregulating the TGF-β1 expression and blocking the TGF-β1/Smads pathway. The results of the study indicated that BS inhibited liver fibrosis by regulating the TGF-β1/Smads pathway.

scholarly journals Pharmacological inhibition of autophagy by 3-MA attenuates hyperuricemic nephropathy

2018 ◽  
Vol 132 (21) ◽  
pp. 2299-2322 ◽  
Author(s):  
Jinfang Bao ◽  
Yingfeng Shi ◽  
Min Tao ◽  
Na Liu ◽  
Shougang Zhuang ◽  
...  
Keyword(s):  
Growth Factor ◽  
Signaling Pathways ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Growth Factor Receptor ◽  
Nuclear Factor Κb ◽  
Transforming Growth Factor Β1 ◽  
Renal Tissue ◽  
Tgf Β1

Autophagy has been identified as a cellular process of bulk degradation of cytoplasmic components and its persistent activation is critically involved in the renal damage induced by ureteral obstruction. However, the role and underlying mechanisms of autophagy in hyperuricemic nephropathy (HN) remain unknown. In the present study, we observed that inhibition of autophagy by 3-methyladenine (3-MA) abolished uric acid-induced differentiation of renal fibroblasts to myofibroblasts and activation of transforming growth factor-β1 (TGF-β1), epidermal growth factor receptor (EGFR), and Wnt signaling pathways in cultured renal interstitial fibroblasts. Treatment with 3-MA also abrogated the development of HN in vivo as evidenced by improving renal function, preserving renal tissue architecture, reducing the number of autophagic vacuoles, and decreasing microalbuminuria. Moreover, 3-MA was effective in attenuating renal deposition of extracellular matrix (ECM) proteins and expression of α-smooth muscle actin (α-SMA) and reducing renal epithelial cells arrested at the G2/M phase of cell cycle. Injury to the kidney resulted in increased expression of TGF-β1 and TGFβ receptor I, phosphorylation of Smad3 and TGF-β-activated kinase 1 (TAK1), and activation of multiple cell signaling pathways associated with renal fibrogenesis, including Wnt, Notch, EGFR, and nuclear factor-κB (NF-κB). 3-MA treatment remarkably inhibited all these responses. In addition, 3-MA effectively suppressed infiltration of macrophages and lymphocytes as well as release of multiple profibrogenic cytokines/chemokines in the injured kidney. Collectively, these findings indicate that hyperuricemia-induced autophagy is critically involved in the activation of renal fibroblasts and development of renal fibrosis and suggest that inhibition of autophagy may represent a potential therapeutic strategy for HN.

scholarly journals Nitric oxide attenuated transforming growth factor-β induced myofibroblast differentiation of human keratocytes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joo-Hee Park ◽  
Martha Kim ◽  
Bora Yim ◽  
Choul Yong Park
Keyword(s):  
Nitric Oxide ◽  
Growth Factor ◽  
Sodium Nitrite ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Corneal Opacity ◽  
Myofibroblast Differentiation ◽  
No Donor ◽  
Tgf Β1 ◽  
Human Keratocytes

AbstractNitric oxide (NO) has the potential to modulate myofibroblast differentiation. In this study, we investigated the effect of exogenous NO on the myofibroblast differentiation of human keratocytes using sodium nitrite as a NO donor. Myofibroblasts were induced by exposing resting keratocytes to transforming growth factor (TGF)-β1. N-cadherin and α-smooth muscle actin (αSMA) were used as myofibroblast markers. Both resting keratocytes and -stimulated keratocytes were exposed to various concentrations of sodium nitrite (1 μM to 1000 mM) for 24 to 72 h. Exposure to sodium nitrite did not alter keratocytes’ viability up to a 10 mM concentration for 72 h. However, significant cytotoxicity was observed in higher concentrations of sodium nitrite (over 100 mM). The expression of αSMA and N-cadherin was significantly increased in keratocytes by TGF-β1 stimulation after 72 h incubation. The addition of sodium nitrite (1 mM) to TGF-β1-stimulated keratocytes significantly decreased αSMA and N cadherin expression. Smad3 phosphorylation decreased after sodium nitrite (1 mM) exposure in TGF-β1-stimulated keratocytes. The effect of NO was reversed when NO scavenger, 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) was added in the culture medium. Application of sodium nitrite resulted in significant decrease of corneal opacity when measured at 2 weeks after the chemical burn in the mouse. These results verified the potential therapeutic effect of NO to decrease myofibroblast differentiation of human keratocytes and corneal opacity after injury.

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