scholarly journals Critical Role of mTORC2-Akt Signaling in TGF-β1-Induced Myofibroblast Differentiation of Human Pterygium Fibroblasts

2019 ◽  
Vol 60 (1) ◽  
pp. 82 ◽  
Author(s):  
Sun Woong Kim ◽  
Hye-In Kim ◽  
Bikash Thapa ◽  
Selikem Nuwormegbe ◽  
Keunwook Lee
Keyword(s):  
Critical Role ◽  
Akt Signaling ◽  
Myofibroblast Differentiation ◽  
Human Pterygium Fibroblasts ◽  
Tgf Β1

scholarly journals Critical Role of Serum Response Factor in Pulmonary Myofibroblast Differentiation Induced by TGF-β

2009 ◽  
Vol 41 (3) ◽  
pp. 332-338 ◽  
Author(s):  
Nathan Sandbo ◽  
Steven Kregel ◽  
Sebastien Taurin ◽  
Sangeeta Bhorade ◽  
Nickolai O. Dulin
Keyword(s):  
Serum Response Factor ◽  
Critical Role ◽  
Myofibroblast Differentiation ◽  
Response Factor ◽  
Serum Response

TGF-β1-Induced Long-Term Changes in Neuronal Excitability in Aplysia Sensory Neurons Depend on MAPK

2006 ◽  
Vol 95 (5) ◽  
pp. 3286-3290 ◽  
Author(s):  
Jeannie Chin ◽  
Rong-Yu Liu ◽  
Leonard J. Cleary ◽  
Arnold Eskin ◽  
John H. Byrne
Keyword(s):  
Sensory Neuron ◽  
Transforming Growth Factor Beta ◽  
Neuronal Excitability ◽  
Transforming Growth Factor ◽  
Critical Role ◽  
Camp Response Element Binding ◽  
Long Term Changes ◽  
Tgf Β1

Transforming growth factor beta-1 (TGF-β1) plays important roles in the early development of the nervous system and has been implicated in neuronal plasticity in adult organisms. It induces long-term increases in sensory neuron excitability in Aplysia as well as a long-term enhancement of synaptic efficacy at sensorimotor synapses. In addition, TGF-β1 acutely regulates synapsin phosphorylation and reduces synaptic depression induced by low-frequency stimuli. Because of the critical role of MAPK in other forms of long-term plasticity in Aplysia, we examined the role of MAPK in TGF-β1-induced long-term changes in neuronal excitability. Prolonged (6 h) exposure to TGF-β1 induced long-term increases in excitability. We confirmed this finding and now report that exposure to TGF-β1 was sufficient to activate MAPK and increase nuclear levels of active MAPK. Moreover, TGF-β1 enhanced phosphorylation of the Aplysia transcriptional activator cAMP response element binding protein (CREB)1, a homologue to vertebrate CREB. Both the TGF-β1-induced long-term changes in neuronal excitability and the phosphorylation of CREB1 were blocked in the presence of an inhibitor of the MAPK cascade, confirming a role for MAPK in long-term modulation of sensory neuron function.

scholarly journals MDM2 mediates fibroblast activation and renal tubulointerstitial fibrosis via a p53-independent pathway

2017 ◽  
Vol 312 (4) ◽  
pp. F760-F768 ◽  
Author(s):  
Chen Ye ◽  
Hui Tang ◽  
Zheng Zhao ◽  
Chun-Tao Lei ◽  
Chao-Qun You ◽  
...  
Keyword(s):  
Critical Role ◽  
Tubulointerstitial Fibrosis ◽  
Podocyte Injury ◽  
Fibroblast Activation ◽  
Downstream Signaling ◽  
Renal Tubulointerstitial Fibrosis ◽  
Inflammatory Processes ◽  
Tgf Β1

It is well recognized that murine double minute gene 2 (MDM2) plays a critical role in cell proliferation and inflammatory processes during tumorigenesis. It is also reported that MDM2 is expressed in glomeruli and involved in podocyte injury. However, whether MDM2 is implicated in renal fibrosis remains unclear. Here we investigated the role of MDM2 in tubulointerstitial fibrosis (TIF). By immunohistochemical staining and Western blotting we confirmed that MDM2 is upregulated in the tubulointerstitial compartment in patients with TIF and unilateral urethral obstruction (UUO) mice, which mainly originates from myofibroblasts. Consistently, in vitro MDM2 is increased in TGF-β1-treated fibroblasts, one of the major sources of collagen-producing myofibroblasts during TIF, along with fibroblast activation. Importantly, genetic deletion of MDM2 significantly attenuates fibroblast activation. We then analyzed the possible downstream signaling of MDM2 during fibroblast activation. p53-dependent pathway is the classic downstream signaling of MDM2, and Nutlin-3 is a small molecular inhibitor of MDM2-p53 interaction. To our surprise, Nutlin-3 could not ameliorate fibroblast activation in vitro and TIF in UUO mice. However, we found that Notch1 signaling is attenuated during fibroblast activation, which could be markedly rescued by MDM2 knockdown. Overexpression of intracellular domain of Notch1 (NICD) by plasmid could obviously minimize fibroblast activation induced by TGF-β1. In addition, the degradation of NICD is strikingly suppressed by PYR-41, an inhibitor of ubiquitin-activating enzyme E1, and proteasome inhibitor MG132. Taken together, our findings provide the first evidence that MDM2 is involved in fibroblast activation and TIF, which associates with Notch1 ubiquitination and proteasome degradation.

scholarly journals Metformin Attenuates Renal Fibrosis in a Mouse Model of Adenine-Induced Renal Injury Through Inhibiting TGF-β1 Signaling Pathways

2021 ◽  
Vol 9 ◽  
Author(s):  
Hao Yi ◽  
Chunling Huang ◽  
Ying Shi ◽  
Qinghua Cao ◽  
Jason Chen ◽  
...  
Keyword(s):  
Mouse Model ◽  
Signaling Pathways ◽  
Renal Fibrosis ◽  
Critical Role ◽  
Glucose Lowering ◽  
Type Iv ◽  
Amp Activated Protein Kinase ◽  
Tgf Β1

It is well-known that all progressive chronic kidney disease (CKD) is pathologically characterized by tubulointerstitial fibrosis process. Multiple studies have shown the critical role of inflammation and fibrosis in the development of CKD. Hence strategies that target inflammatory and fibrotic signaling pathways may provide promising opportunities to protect against renal fibrosis. Metformin has been used as the first-line glucose-lowering agent to treat patients with type 2 diabetes mellitus (T2DM) for over 50 years. Accumulating evidence suggests the potential for additional therapeutic applications of metformin, including mitigation of renal fibrosis. In this study, the anti-fibrotic effects of metformin independent of its glucose-lowering mechanism were examined in an adenine -induced mouse model of CKD. Expressions of inflammatory markers MCP-1, F4/80 and ICAM, fibrotic markers type IV collagen and fibronectin, and the cytokine TGF-β1 were increased in adenine-induced CKD when compared to control groups and significantly attenuated by metformin treatment. Moreover, treatment with metformin inhibited the phosphorylation of Smad3, ERK1/2, and P38 and was associated with activation of the AMP-activated protein kinase (AMPK) in the kidneys of adenine-treated mice. These results indicate that metformin attenuates adenine-induced renal fibrosis through inhibition of TGF-β1 signaling pathways and activation of AMPK, independent of its glucose-lowering action.

scholarly journals Expression and Clinical Significance of Mucin Gene in Chronic Rhinosinusitis

2020 ◽  
Vol 20 (11) ◽  
Author(s):  
Jiaxin Tong ◽  
Qingjia Gu
Keyword(s):  
Chronic Rhinosinusitis ◽  
Transforming Growth Factor ◽  
Critical Role ◽  
Transforming Growth Factor Β1 ◽  
Inflammatory Factors ◽  
Human Neutrophil Elastase ◽  
Mucin Expression ◽  
Nasal Disease ◽  
Tgf Β1

Abstract Purpose of Review This review highlights the expression and regulation of mucin in CRS and discusses its clinical implications. Recent Findings Chronic rhinosinusitis (CRS) is common chronic nasal disease; one of its main manifestations and important features is mucus overproduction. Mucin is the major component of mucus and plays a critical role in the pathophysiological changes in CRS. The phenotype of CRS affects the expression of various mucins, especially in nasal polyps (NP). Corticosteroids(CS), human neutrophil elastase (HNE), and transforming growth factor-β1 (TGF-β1) are closely related to the tissue remodeling of CRS and regulate mucin expression, mainly MUC1, MUC4, MUC5AC, and MUC5B. “It is expected that CS, HNE and TGF - β could be used to regulate the expression of mucin in CRS.” However, at present, the research on mucin is mainly focused on mucin 5AC and mucin 5B, which is bad for finding new therapeutic targets. Summary Investigating the expression and location of mucin in nasal mucosa and understanding the role of various inflammatory factors in mucin expression are helpful to figure out regulatory mechanisms of airway mucin hypersecretion. It is of great significance for the treatment of CRS.

Abstract 635: Role of Micro RNA-21 in Venous Neointimal Hyperplasia (VNH): Implications in Targeting MiR-21 For VNH Treatment

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Sreenivasulu Kialri ◽  
Binxia Yang ◽  
Deborah McCall ◽  
Sanjay Misra
Keyword(s):  
Molecular Mechanisms ◽  
Target Genes ◽  
Transforming Growth Factor ◽  
Neointimal Hyperplasia ◽  
Micro Rna ◽  
Coronary Artery Bypass Grafts ◽  
Myofibroblast Differentiation ◽  
Down Regulation ◽  
Tgf Β1

The exact molecular mechanisms involved in hemodialysis arteriovenous fistula (AVF) failure caused by venous neointimal hyperplasia (VNH) are not clear. It has been observed that there is an accumulation of extracellular matrix and up regulation of pro-fibrotic genes accompanied with presence of fibroblasts, smooth muscle cells, and inflammatory cells in the stenotic veins. Previous studies have demonstrated that adventitial and medial fibroblasts have a pivotal role(s) in VNH formation. MicroRNA-21 (miR-21) contributes to fibroblast to myofibroblast differentiation and dysregulation of miR-21 plays a pathological role in failure of coronary artery bypass grafts. The aim of the present study was to determine the role of miR-21 in VNH associated with AVF. We assessed miR-21 expression using qRT-PCR in the outflow veins of AVFs compared to control (contralateral jugular veins) veins in the C57BL/6J mice with chronic kidney disease (CKD). MiR-21 expression was upregulated accompanied with down regulation of miR-21 target genes; PPAR-α, PTEN and TIMP-3. In addition, gene expression of fibroblast specific protein (FSP) -1, TGF (transforming growth factor) -β1, matrix metalloproteinases (MMP)-2, -9, collagen-I, and IV were significantly increased at day 7 after AVF creation. Immunohistochemistry revealed that there was a significant increase in proliferating cell index (Ki-67) and fibroblast index (FSP-1) in the outflow veins of AVFs. Hypoxia has been shown to increase fibroblast to myofibroblast differentiation and this is predicted to be an early step in VNH formation. Therefore we assessed miR-21 expression in hypoxic (1%O 2 ) mouse pulmonary vein fibroblasts compared to normoxic cells in vitro and it was found that miR-21and TGF-β1 significantly elevated with down regulation of miR-21 target genes PTEN and TIMP-3. Furthermore, miR-21 knockdown in hypoxic fibroblasts attenuated TGF-β1 expression with a significant upregulation of genes targeted by miR-21 compared to controls. Together these results indicate that upregulation of miR-21 expression may result in fibroblast to myofibroblast differentiation resulting in VNH formation.

scholarly journals Neuronal Wiskott-Aldrich syndrome protein (N-WASP) is critical for formation of α-smooth muscle actin filaments during myofibroblast differentiation

2012 ◽  
Vol 303 (8) ◽  
pp. L692-L702 ◽  
Author(s):  
Guo-Qiang Cai ◽  
Chu-Fang Chou ◽  
Meng Hu ◽  
Anni Zheng ◽  
Louis F. Reichardt ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Actin ◽  
Critical Role ◽  
Lung Fibroblasts ◽  
Myofibroblast Differentiation ◽  
Muscle Actin ◽  
Wiskott Aldrich Syndrome ◽  
Cytoplasmic Filaments ◽  
Syndrome Protein ◽  
Tgf Β1

Myofibroblasts are implicated in pathological stromal responses associated with lung fibrosis. One prominent phenotypic marker of fully differentiated myofibroblasts is the polymerized, thick cytoplasmic filaments containing newly synthesized α-smooth muscle actin (α-SMA). These α-SMA-containing cytoplasmic filaments are important for myofibroblast contractility during tissue remodeling. However, the molecular mechanisms regulating the formation and maturation of α-SMA-containing filaments have not been defined. This study demonstrates a critical role for neuronal Wiskott-Aldrich syndrome protein (N-WASP) in regulating the formation of α-SMA-containing cytoplasmic filaments during myofibroblast differentiation and in myofibroblast contractility. Focal adhesion kinase (FAK) is activated by transforming growth factor-β1 (TGF-β1) and is required for phosphorylation of tyrosine residue 256 (Y256) of N-WASP. Phosphorylation of Y256 of N-WASP is essential for TGF-β1-induced formation of α-SMA-containing cytoplasmic filaments in primary human lung fibroblasts. In addition, we demonstrate that actin-related protein (Arp) 2/3 complex is downstream of N-WASP and mediates the maturation of α-SMA-containing cytoplasmic filaments. Together, this study supports a critical role of N-WASP in integrating FAK and Arp2/3 signaling to mediate formation of α-SMA-containing cytoplasmic filaments during myofibroblast differentiation and maturation.

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