scholarly journals Notch Signaling Molecules Activate TGF-βin Rat Mesangial Cells under High Glucose Conditions

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Li Liu ◽  
Chenlin Gao ◽  
Guo Chen ◽  
Xia Li ◽  
Jia Li ◽  
...  

The involvement of the Notch signaling pathway in the cellular differentiation of the mammalian kidney is established. Recently, the dysregulation of Notch signaling molecules has been identified in acute and chronic renal injuries, fibrosis models, and diabetic kidney biopsies. The canonical Notch ligand , Jagged1, is upregulated in a transforming growth factor-beta- (TGF-β-) dependent manner during chronic kidney disease. TGF-β, a central mediator of renal fibrosis, also is a major contributor to the development of diabetic nephropathy. To explore the roles and possible mechanisms of Notch signaling molecules in the pathogenesis of diabetic nephropathy, we exposed cultured rat mesangial cells to aγ-secretase inhibitor (DAPT) or high glucose and measured the expression of Notch signaling molecules and the fibrosis index. Notch pathway-related molecules, TGF-β, and fibronectin increased with exposure to high glucose and decreased with DAPT treatment. Our results suggest that the Notch signaling pathway may precipitate diabetic nephropathy via TGF-βactivation.

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Le Zhang ◽  
Qian Dai ◽  
Lanlan Hu ◽  
Hua Yu ◽  
Jing Qiu ◽  
...  

Purpose. Hyperoside, a flavonoid isolated from conventional medicinal herbs, has been demonstrated to exert a significant protective effect in diabetic nephropathy. This study aimed to determine the underlying mechanisms, by which hyperoside inhibits high glucose-(HG-) induced proliferation in mouse renal mesangial cells. Methods. Mouse glomerular mesangial cells line (SV40-MES13) was used to study the inhibitory effect of hyperoside on cell proliferation induced by 30 mM glucose, which was used to simulate a diabetic condition. Viable cell count was assessed using the Cell Counting Kit-8 and by the 5-ethynyl-20-deoxyuridine incorporation assay. The underlying mechanism involving miRNA-34a was further investigated by quantitative RT-PCR and transfection with miRNA-34a agomir. The phosphorylation levels of extracellular signal-regulated kinases (ERKs) and cAMP-response element-binding protein (CREB) were measured by Western blotting. The binding region and the critical binding sites of CREB in the miRNA-34a promoter were investigated by the chromatin immunoprecipitation assay and luciferase reporter assay, respectively. Results. We found that hyperoside could significantly decrease HG-induced proliferation of SV40-MES13 cells in a dose-dependent manner, without causing obvious cell death. In addition, hyperoside inhibited the activation of ERK pathway and phosphorylation of its downstream transcriptional factor CREB, as well as the miRNA-34a expression. We further confirmed that CREB-mediated regulation of miRNA-34a is dependent on the direct binding to specific sites in the promoter region of miRNA-34a. Conclusion. Our cumulative results suggested that hyperoside inhibits the proliferation of SV40-MES13 cells through the suppression of the ERK/CREB/miRNA-34a signaling pathway, which provides new insight to the current investigation on therapeutic strategies for diabetic nephropathy.


2020 ◽  
Vol 318 (3) ◽  
pp. F673-F682
Author(s):  
Parisa Yazdizadeh Shotorbani ◽  
Sarika Chaudhari ◽  
Yu Tao ◽  
Leonidas Tsiokas ◽  
Rong Ma

Overproduction of extracellular matrix proteins, including fibronectin by mesangial cells (MCs), contributes to diabetic nephropathy. Inhibitor of myogenic differentiation family isoform a (I-mfa) is a multifunctional cytosolic protein functioning as a transcriptional modulator or plasma channel protein regulator. However, its renal effects are unknown. The present study was conducted to determine whether I-mfa regulated fibronectin production by glomerular MCs. In human MCs, overexpression of I-mfa significantly increased fibronectin abundance. Silencing I-mfa significantly reduced the level of fibronectin mRNA and blunted transforming growth factor-β1-stimulated production of fibronectin. We further found that high glucose increased I-mfa protein content in a time course (≥48 h) and concentration (≥25 mM)-dependent manner. Although high glucose exposure increased I-mfa at the protein level, it did not significantly alter transcripts of I-mfa in MCs. Furthermore, the abundance of I-mfa protein was significantly increased in the renal cortex of rats with diabetic nephropathy. The I-mfa protein level was also elevated in the glomerulus of mice with diabetic kidney disease. However, there was no significant difference in glomerular I-mfa mRNA levels between mice with and without diabetic nephropathy. Moreover, H2O2 significantly increased I-mfa protein abundance in a dose-dependent manner in cultured human MCs. The antioxidants polyethylene glycol-catalase, ammonium pyrrolidithiocarbamate, and N-acetylcysteine significantly blocked the high glucose-induced increase of I-mfa protein. Taken together, our results suggest that I-mfa, increased by high glucose/diabetes through the production of reactive oxygen species, stimulates fibronectin production by MCs.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hong Feng ◽  
Junling Gu ◽  
Fang Gou ◽  
Wei Huang ◽  
Chenlin Gao ◽  
...  

While inflammation is considered a central component in the development in diabetic nephropathy, the mechanism remains unclear. The NLRP3 inflammasome acts as both a sensor and a regulator of the inflammatory response. The NLRP3 inflammasome responds to exogenous and endogenous danger signals, resulting in cleavage of procaspase-1 and activation of cytokines IL-1β, IL-18, and IL-33, ultimately triggering an inflammatory cascade reaction. This study observed the expression of NLRP3 inflammasome signaling stimulated by high glucose, lipopolysaccharide, and reactive oxygen species (ROS) inhibitor N-acetyl-L-cysteine in glomerular mesangial cells, aiming to elucidate the mechanism by which the NLRP3 inflammasome signaling pathway may contribute to diabetic nephropathy. We found that the expression of thioredoxin-interacting protein (TXNIP), NLRP3, and IL-1βwas observed by immunohistochemistry in vivo. Simultaneously, the mRNA and protein levels of TXNIP, NLRP3, procaspase-1, and IL-1βwere significantly induced by high glucose concentration and lipopolysaccharide in a dose-dependent and time-dependent manner in vitro. This induction by both high glucose and lipopolysaccharide was significantly inhibited by N-acetyl-L-cysteine. Our results firstly reveal that high glucose and lipopolysaccharide activate ROS/TXNIP/ NLRP3/IL-1βinflammasome signaling in glomerular mesangial cells, suggesting a mechanism by which inflammation may contribute to the development of diabetic nephropathy.


Development ◽  
2002 ◽  
Vol 129 (12) ◽  
pp. 2929-2946 ◽  
Author(s):  
Andrew C. Oates ◽  
Robert K. Ho

We have examined the expression of a Hairy/E(spl)-related (Her) gene, her7, in the zebrafish and show that its expression in the PSM cycles similarly to her1 and deltaC. A decrease in her7 function generated by antisense oligonucleotides disrupts somite formation in the posterior trunk and tail, and disrupts the dynamic expression domains of her1 and deltaC, suggesting that her7 plays a role in coordinating the oscillations of neighboring cells in the presomitic mesoderm. This phenotype is reminiscent of zebrafish segmentation mutants with lesions in genes of the Delta/Notch signaling pathway, which also show a disruption of cyclic her7 expression. The interaction of HER genes with the Delta/Notch signaling system was investigated by introducing a loss of her7 function into mutant backgrounds. This leads to segmental defects more anterior than in either condition alone. Combining a decrease of her7 function with reduction of her1 function results in an enhanced phenotype that affects all the anterior segments, indicating that Her functions in the anterior segments are also partially redundant. In these animals, gene expression does not cycle at any time, suggesting that a complete loss of oscillator function had been achieved. Consistent with this, combining a reduction of her7 and her1 function with a Delta/Notch mutant genotype does not worsen the phenotype further. Thus, our results identify members of the Her family of transcription factors that together behave as a central component of the oscillator, and not as an output. This indicates, therefore, that the function of the segmentation oscillator is restricted to the positioning of segmental boundaries. Furthermore, our data suggest that redundancy between Her genes and genes of the Delta/Notch pathway is in part responsible for the robust formation of anterior somites in vertebrates.


Author(s):  
Germán Saucedo-Correa ◽  
Alejandro Bravo-Patiño ◽  
Rosa Elvira Núñez-Anita ◽  
Javier Oviedo-Boyso ◽  
Juan José Valdez-Alarcón ◽  
...  

Notch is a cell-signaling pathway that is highly conserved in all metazoans and is responsible for cell differentiation and cross-talk communication with other signaling pathways such as WNT and Hh. In most cancers, the Notch signaling pathway is altered, causing atypical activity of vital processes such as cell cycle, differentiation and apoptosis, leading the cell to a carcinogenic state. Currently, the Notch signaling pathway has taken a special interest to design strategies in order to regulate the activity of this pathway since it is known that in the cancer molecular micro-environment the Notch pathway is over-expressed or presents an aberrant function, which, in consequence, corrupts the cross-talk communication with WNT and Hh pathways. Most of the existing strategies are focused on the systematic and whole inhibition of Notch pathway at the membrane level by the use of γ-secretases inhibitors. There are few strategies that act at the nuclear level inhibiting the activity of the transcriptional activation complex composed by the Notch intracellular domain, the transcriptional factor CSL and the Mastermind co-activator. In this review, by the fact that there are not any strategy focused to revert the over expression effect caused by the Notch pathway constitutive activity, we propose that the efforts to develop new strategies against cancer should be focused to understand the complexity of the cross-talk communication between Notch, WNT and Hh pathways to neutralize the gene aberrant activity characteristic of cancer cells which are responsible for those corrupted cross-talk communication.


Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1879 ◽  
Author(s):  
Christian T. Meisel ◽  
Cristina Porcheri ◽  
Thimios A. Mitsiadis

The Notch signaling pathway regulates cell proliferation, cytodifferentiation and cell fate decisions in both embryonic and adult life. Several aspects of stem cell maintenance are dependent from the functionality and fine tuning of the Notch pathway. In cancer, Notch is specifically involved in preserving self-renewal and amplification of cancer stem cells, supporting the formation, spread and recurrence of the tumor. As the function of Notch signaling is context dependent, we here provide an overview of its activity in a variety of tumors, focusing mostly on its role in the maintenance of the undifferentiated subset of cancer cells. Finally, we analyze the potential of molecules of the Notch pathway as diagnostic and therapeutic tools against the various cancers.


2011 ◽  
Vol 301 (4) ◽  
pp. E713-E726 ◽  
Author(s):  
Howard Goldberg ◽  
Catharine Whiteside ◽  
I. George Fantus

Hyperglycemia augments flux through the hexosamine biosynthetic pathway and subsequent O-linkage of single β- N-acetyl-d-glucosamine moieties to serine and threonine residues on cytoplasmic and nuclear proteins ( O-GlcNAcylation). Perturbations in this posttranslational modification have been proposed to promote glomerular matrix accumulation in diabetic nephropathy, but clear evidence and mechanism are lacking. We tested the hypothesis that O-GlcNAcylation enhances profibrotic signaling in rat mesangial cells. An adenovirus expressing shRNA directed against O-GlcNAc transferase (OGT) markedly reduced basal and high-glucose-stimulated O-GlcNAcylation. Interestingly, O-GlcNAc depletion prevented high-glucose-induced p38 mitogen-activated protein kinase (MAPK) and c-Jun NH2-terminal kinase phosphorylation. Downstream of p38, O-GlcNAc controlled the expression of plasminogen activator inhibitor-1, fibronectin, and transforming growth factor-β, important factors in matrix accumulation in diabetic nephropathy. Treating mesangial cells with thiamet-G, a highly selective inhibitor of O-GlcNAc-specific hexosaminidase ( O-GlcNAcase), increased O-GlcNAcylation and p38 phosphorylation. The high-glucose-stimulated kinase activity of apoptosis signal-regulating kinase 1 (ASK1), an upstream MAPK kinase kinase for p38 that is negatively regulated by Akt, was inhibited by OGT shRNA. Akt Thr308 and Ser473 phosphorylation were enhanced following OGT shRNA expression in high-glucose-exposed mesangial cells, but high-glucose-induced p38 phosphorylation was not attenuated by OGT shRNA in cells pretreated with the phosphatidylinositol 3-kinase inhibitor LY-294002. OGT shRNA also reduced high-glucose-stimulated reactive oxygen species (ROS) formation. In contrast, diminished O-GlcNAcylation caused elevated ERK phosphorylation and PKCδ membrane translocation. Thus, O-GlcNAcylation is coupled to profibrotic p38 MAPK signaling by high glucose in part through Akt and possibly through ROS.


2013 ◽  
Vol 19 (4) ◽  
pp. 427-437
Author(s):  
Nadežda Lachej ◽  
Janina Didžiapetrienė ◽  
Birutė Kazbarienė ◽  
Daiva Kanopienė ◽  
Violeta Jonušienė

Background. The components of the Notch signaling pathway are important in maintaining the balance involved in cell proliferation, apoptosis and differentiation. Therefore, dysfunction of the Notch prevents differentiation, ultimately guiding undifferentiated cells toward malignant transformation. The aim of this article is to present recently published data concerning the role of the Notch signaling pathway components in development and prognosis of oncologic diseases, in occurrence of resistance to cytostatic agents and importance in creating of new cancer treatment approaches. Materials and methods. The Pubmed was the main source of looking for information for this article. Results. Recent investigations show that disorders of the Notch signaling pathway are associated with development of some human haematological and solid cancers. In different tissues and organs this active pathway can act as a tumor suppressor or an oncogene. Accordingly, the increased or decreased expression of its components is defined. Most of published data show that the increased expression of Notch pathway components correlates with a worse prognosis of cancer and a shorter survival. Recently, the Notch pathway has been reported to be involved in drug resistance. The modulation of the Notch signaling pathway could be helpful in treatment of some tumors with abnormal activity of this pathway’s components. Therefore changes in the expression of Notch components could become important predictive factors, helpful in selecting the proper treatment method. Conclusions. The results of recent studies are very important, since the detecting of the prognostic and predictive value of components of the Notch signaling pathway can allow creating new and improving already known methods of cancer diagnostic and treatment.


2006 ◽  
Vol 26 (13) ◽  
pp. 4769-4774 ◽  
Author(s):  
Céline Souilhol ◽  
Sarah Cormier ◽  
Kenji Tanigaki ◽  
Charles Babinet ◽  
Michel Cohen-Tannoudji

ABSTRACT The Notch signaling pathway is an evolutionarily conserved signaling system which has been shown to be essential in cell fate specification and in numerous aspects of embryonic development in all metazoans thus far studied. We recently demonstrated that several components of the Notch signaling pathway, including the four Notch receptors and their five ligands known in mammals, are expressed in mouse oocytes, in mouse preimplantation embryos, or both. This suggested a possible implication of the Notch pathway in the first cell fate specification of the dividing mouse embryo, which results in the formation of the blastocyst. To address this issue directly, we generated zygotes in which both the maternal and the zygotic expression of Rbpsuh, a key element of the core Notch signaling pathway, were abrogated. We find that such zygotes give rise to blastocysts which implant and develop normally. Nevertheless, after gastrulation, these embryos die around midgestation, similarly to Rbpsuh-null mutants. This demonstrates that the RBP-Jκ-dependent pathway, otherwise called the canonical Notch pathway, is dispensable for blastocyst morphogenesis and the establishment of the three germ layers, ectoderm, endoderm, and mesoderm. These results are discussed in the light of recent observations which have challenged this conclusion.


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