scholarly journals Epigenetic Modulation of Gremlin-1/NOTCH Pathway in Experimental Crescentic Immune-Mediated Glomerulonephritis

Author(s):  
Lucia Tejedor-Santamaria ◽  
Jose Luis Morgado-Pascual ◽  
Laura Marquez-Exposito ◽  
Beatriz Suarez-Alvarez ◽  
Raul R. Rodrigues-Diez ◽  
...  

Crescentic glomerulonephritis is a devastating autoimmune disease that without early and properly treat-ment may rapidly progress to end-stage renal disease and death. Current immunosuppressive treatment provided limited efficacy and an important burden of adverse events. Epigenetic drugs are a source of novel therapeutic tools. Among them, bromodomain and extraterminal domain (BET) inhibitors (iBETs) block the interaction between bromodomains and acetylated proteins, including histones and transcription factors. iBETs have demonstrated protective effects on malignancy, inflammatory conditions and experi-mental kidney disease. Recently, Gremlin-1 was proposed as a urinary biomarker of disease progression in human anti-neutrophil cytoplasmic antibody (ANCA)-associated crescentic glomerulonephritis. We have now evaluated whether iBETs regulate Gremlin-1 in experimental anti-glomerular basement membrane nephritis induced by nephrotoxic serum (NTS) in mice, a model of human crescentic glomerulonephritis. In NTS-injected mice, the iBET JQ1 inhibited renal Gremlin-1 overexpression and diminished glomerular damage, including podocyte loss. Chromatin immunoprecipitation assay demonstrated BRD4 enrichment of the Grem-1 gene promoter in injured kidneys, consistent with Gremlin-1 epigenetic regulation. Moreover, JQ1 blocked BRD4 binding and inhibited Grem-1 gene transcription. The beneficial effect of iBETs was also mediated by targeting NOTCH signaling pathway. JQ1 inhibited the gene expression of the NOTCH effec-tors Hes-1 and Hey-1 in NTS-injured kidneys. Our results further support the role for epigenetic drugs, such as iBETs, in the treatment of rapidly progressive crescentic glomerulonephritis.

Author(s):  
Lucia Tejedor-Santamaria ◽  
Jose Luis Morgado-Pascual ◽  
Laura Marquez-Exposito ◽  
Beatriz Suarez-Alvarez ◽  
Raul R. Rodrigues-Diez ◽  
...  

Crescentic glomerulonephritis is a devastating autoimmune disease that without early and properly treat-ment may rapidly progress to end-stage renal disease and death. Current immunosuppressive treatment provided limited efficacy and an important burden of adverse events. Epigenetic drugs are a source of novel therapeutic tools. Among them, bromodomain and extraterminal domain (BET) inhibitors (iBETs) block the interaction between bromodomains and acetylated proteins, including histones and transcription factors. iBETs have demonstrated protective effects on malignancy, inflammatory conditions and experi-mental kidney disease. Recently, Gremlin-1 was proposed as a urinary biomarker of disease progression in human anti-neutrophil cytoplasmic antibody (ANCA)-associated crescentic glomerulonephritis. We have now evaluated whether iBETs regulate Gremlin-1 in experimental anti-glomerular basement membrane nephritis induced by nephrotoxic serum (NTS) in mice, a model of human crescentic glomerulonephritis. In NTS-injected mice, the iBET JQ1 inhibited renal Gremlin-1 overexpression and diminished glomerular damage, including podocyte loss. Chromatin immunoprecipitation assay demonstrated BRD4 enrichment of the Grem-1 gene promoter in injured kidneys, consistent with Gremlin-1 epigenetic regulation. Moreover, JQ1 blocked BRD4 binding and inhibited Grem-1 gene transcription. The beneficial effect of iBETs was also mediated by targeting NOTCH signaling pathway. JQ1 inhibited the gene expression of the NOTCH effec-tors Hes-1 and Hey-1 in NTS-injured kidneys. Our results further support the role for epigenetic drugs, such as iBETs, in the treatment of rapidly progressive crescentic glomerulonephritis.


Author(s):  
Lucia Tejedor-Santamaria ◽  
Jose Luis Morgado-Pascual ◽  
Laura Marquez-Exposito ◽  
Beatriz Suarez-Alvarez ◽  
Raul R. Rodrigues-Diez ◽  
...  

Crescentic glomerulonephritis is a devastating autoimmune disease that without early and properly treat-ment may rapidly progress to end-stage renal disease and death. Current immunosuppressive treatment provided limited efficacy and an important burden of adverse events. Epigenetic drugs are a source of novel therapeutic tools. Among them, bromodomain and extraterminal domain (BET) inhibitors (iBETs) block the interaction between bromodomains and acetylated proteins, including histones and transcription factors. iBETs have demonstrated protective effects on malignancy, inflammatory conditions and experi-mental kidney disease. Recently, Gremlin-1 was proposed as a urinary biomarker of disease progression in human anti-neutrophil cytoplasmic antibody (ANCA)-associated crescentic glomerulonephritis. We have now evaluated whether iBETs regulate Gremlin-1 in experimental anti-glomerular basement membrane nephritis induced by nephrotoxic serum (NTS) in mice, a model of human crescentic glomerulonephritis. In NTS-injected mice, the iBET JQ1 inhibited renal Gremlin-1 overexpression and diminished glomerular damage, including podocyte loss. Chromatin immunoprecipitation assay demonstrated BRD4 enrichment of the Grem-1 gene promoter in injured kidneys, consistent with Gremlin-1 epigenetic regulation. Moreover, JQ1 blocked BRD4 binding and inhibited Grem-1 gene transcription. The beneficial effect of iBETs was also mediated by targeting NOTCH signaling pathway. JQ1 inhibited the gene expression of the NOTCH effec-tors Hes-1 and Hey-1 in NTS-injured kidneys. Our results further support the role for epigenetic drugs, such as iBETs, in the treatment of rapidly progressive crescentic glomerulonephritis.


Author(s):  
Sudha B. Singh ◽  
Cristina N. Coffman ◽  
Amanda Carroll-Portillo ◽  
Matthew G. Varga ◽  
Henry C. Lin

Sulfate Reducing Bacteria (SRB), usually rare residents of the gut, are often found in increased numbers (called a SRB bloom) in inflammatory conditions such as Inflammatory Bowel Disease (IBD), pouchitis, and periodontitis. However, the underlying mechanisms of this association remain largely unknown. Notch signaling, a conserved cell-cell communication pathway, is usually involved in tissue development and differentiation. Dysregulated Notch signaling is observed in inflammatory conditions such as IBD. Lipolysaccharide and pathogens also activate Notch pathway in macrophages. In this study, we tested whether Desulfovibrio, the most dominant SRB genus in the gut, may activate Notch signaling. RAW 264.7 macrophages were infected with Desulfovibrio vulgaris (DSV) and analyzed for the expression of Notch signaling pathway-related proteins. We found that DSV induced protein expression of Notch1 receptor, Notch intracellular domain (NICD) and p21, a downstream Notch target, in a dose-and time-dependent manner. DSV also induced the expression of pro-IL1β, a precursor of IL-1β, and SOCS3, a regulator of cytokine signaling. The gamma secretase inhibitor DAPT or Notch siRNA dampened DSV-induced Notch-related protein expression as well the expression of pro-IL1β and SOCS3. Induction of Notch-related proteins by DSV was not affected by TLR4 -IN -C34(C34), a TLR4 receptor antagonist. Additionally, cell-free supernatant of DSV-infected macrophages induced NICD expression in uninfected macrophages. DSV also activated Notch pathway in the human epithelial cell line HCT116 and in mouse small intestine. Thus, our study uncovers a novel mechanism by which SRB interact with host cells by activating Notch signaling pathway. Our study lays a framework for examining whether the Notch pathway induced by SRB contributes to inflammation in conditions associated with SRB bloom and whether it can be targeted as a therapeutic approach to treat these conditions.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Michittra Boonchan ◽  
Hideki Arimochi ◽  
Kunihiro Otsuka ◽  
Tomoko Kobayashi ◽  
Hisanori Uehara ◽  
...  

AbstractThe sensing of various extrinsic stimuli triggers the receptor-interacting protein kinase-3 (RIPK3)-mediated signaling pathway, which leads to mixed-lineage kinase-like (MLKL) phosphorylation followed by necroptosis. Although necroptosis is a form of cell death and is involved in inflammatory conditions, the roles of necroptosis in acute pancreatitis (AP) remain unclear. In the current study, we administered caerulein to Ripk3- or Mlkl-deficient mice (Ripk3−/− or Mlkl−/− mice, respectively) and assessed the roles of necroptosis in AP. We found that Ripk3−/− mice had significantly more severe pancreatic edema and inflammation associated with macrophage and neutrophil infiltration than control mice. Consistently, Mlkl−/− mice were more susceptible to caerulein-induced AP, which occurred in a time- and dose-dependent manner, than control mice. Mlkl−/− mice exhibit weight loss, edematous pancreatitis, necrotizing pancreatitis, and acinar cell dedifferentiation in response to tissue damage. Genetic deletion of Mlkl resulted in downregulation of the antiapoptotic genes Bclxl and Cflar in association with increases in the numbers of apoptotic cells, as detected by TUNEL assay. These findings suggest that RIPK3 and MLKL-mediated necroptosis exerts protective effects in AP and caution against the use of necroptosis inhibitors for AP treatment.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Danielle Perez-Bercoff ◽  
Hélène Laude ◽  
Morgane Lemaire ◽  
Oliver Hunewald ◽  
Valérie Thiers ◽  
...  

AbstractAPOBEC3 (A3) enzymes are best known for their role as antiviral restriction factors and as mutagens in cancer. Although four of them, A3A, A3B, A3F and A3G, are induced by type-1-interferon (IFN-I), their role in inflammatory conditions is unknown. We thus investigated the expression of A3, and particularly A3A and A3B because of their ability to edit cellular DNA, in Systemic Lupus Erythematosus (SLE), a chronic inflammatory disease characterized by high IFN-α serum levels. In a cohort of 57 SLE patients, A3A and A3B, but also A3C and A3G, were upregulated ~ 10 to 15-fold (> 1000-fold for A3B) compared to healthy controls, particularly in patients with flares and elevated serum IFN-α levels. Hydroxychloroquine, corticosteroids and immunosuppressive treatment did not reverse A3 levels. The A3AΔ3B polymorphism, which potentiates A3A, was detected in 14.9% of patients and in 10% of controls, and was associated with higher A3A mRNA expression. A3A and A3B mRNA levels, but not A3C or A3G, were correlated positively with dsDNA breaks and negatively with lymphopenia. Exposure of SLE PBMCs to IFN-α in culture induced massive and sustained A3A levels by 4 h and led to massive cell death. Furthermore, the rs2853669 A > G polymorphism in the telomerase reverse transcriptase (TERT) promoter, which disrupts an Ets-TCF-binding site and influences certain cancers, was highly prevalent in SLE patients, possibly contributing to lymphopenia. Taken together, these findings suggest that high baseline A3A and A3B levels may contribute to cell frailty, lymphopenia and to the generation of neoantigens in SLE patients. Targeting A3 expression could be a strategy to reverse cell death and the generation of neoantigens.


2019 ◽  
Vol 41 (2) ◽  
pp. 293-295
Author(s):  
Mehtap Ezel Çelakıl ◽  
Burcu Bozkaya Yücel ◽  
Umay Kiraz Özod ◽  
Kenan Bek

ABSTRACT Pauci-immune glomerulonephritis (GN) is more common in elderly people compared to children and the etiology is not completely understood yet. Antineutrophil cytoplasmic antibody (ANCA) positivity occurs in 80% of the patients. We report a case of a 7-year-old girl who presented with malaise and mildly elevated creatinine diagnosed as ANCA-associated pauci-immune crescentic glomerulonephritis with crescents in 20 of 25 glomeruli (80%). Of these 20 crescents, 12 were cellular, 4 fibrocellular, and 4 globally sclerotic. She did not have purpura, arthritis, or systemic symptoms and she responded well to initial immunosuppressive treatment despite relatively severe histopathology. The patient was given three pulses of intravenous methylprednisolone (30 mg/kg on alternate days) initially and continued with cyclophosphamide (CYC; 2 mg/kg per day) orally for 3 months with prednisone (1 mg/kg per day). In one month, remission was achieved with normal serum creatinine and prednisone was gradually tapered. The case of this child with a relatively rare pediatric disease emphasizes the importance of early and aggressive immunosuppressive treatment in patients with renal-limited ANCA-associated pauci-immune crescentic GN even if with a mild clinical presentation. As in our patient, clinical and laboratory findings might not always exactly reflect the severity of renal histopathology and thus kidney biopsy is mandatory in such children to guide the clinical management and predict prognosis.


2021 ◽  
Vol 118 (5) ◽  
pp. e2005377118
Author(s):  
Weijun Jiang ◽  
Jiajia Shi ◽  
Jingjie Zhao ◽  
Qiu Wang ◽  
Dan Cong ◽  
...  

ZFP57 is a master regulator of genomic imprinting. It has both maternal and zygotic functions that are partially redundant in maintaining DNA methylation at some imprinting control regions (ICRs). In this study, we found that DNA methylation was lost at most known ICRs in Zfp57 mutant embryos. Furthermore, loss of ZFP57 caused loss of parent-of-origin–dependent monoallelic expression of the target imprinted genes. The allelic expression switch occurred in the ZFP57 target imprinted genes upon loss of differential DNA methylation at the ICRs in Zfp57 mutant embryos. Specifically, upon loss of ZFP57, the alleles of the imprinted genes located on the same chromosome with the originally methylated ICR switched their expression to mimic their counterparts on the other chromosome with unmethylated ICR. Consistent with our previous study, ZFP57 could regulate the NOTCH signaling pathway in mouse embryos by impacting allelic expression of a few regulators in the NOTCH pathway. In addition, the imprinted Dlk1 gene that has been implicated in the NOTCH pathway was significantly down-regulated in Zfp57 mutant embryos. Our allelic expression switch models apply to the examined target imprinted genes controlled by either maternally or paternally methylated ICRs. Our results support the view that ZFP57 controls imprinted expression of its target imprinted genes primarily through maintaining differential DNA methylation at the ICRs.


Author(s):  
Ning Xie ◽  
Qin Huang ◽  
Jingting Han ◽  
Wenyuan Xu

IntroductionThis study aims to determine the relationship between the granulocyte colony-stimulating factor (G-CSF) and the Notch signaling pathway in ischemic brain injury.Material and methodsPC-12 cells were treated with the nerve growth factor (NGF) to induce neuronal differentiation then divided into seven groups: 1) no treatment (control); 2) oxygen-glucose deprivation (OGD) model; 3) overexpressed G-CSF + OGD model; 4) transfected empty vector (negative control; NC) + OGD model; 5) overexpressed G-CSF + γ-secretase inhibitor MW167 + OGD model; 6) MW167 + OGD model; and 7) NC + MW167 + OGD model. The cells were analyzed using immunohistochemistry and apoptosis and CCK8 assays. The expression of the related molecules in the Notch pathway was detected using the Western blotting and quantitative PCR (Q-PCR).ResultsMost PC-12 cells were neuron-specific enolase (NSE)-positive after the NGF treatment. When compared with the control group, the MW167 + OGD and NC + MW167 + OGD groups had the lowest optical density (OD) values, followed by the OGD, NC + OGD and the G-CSF + MW167+ OGD groups. The G-CSF + OGD group had the highest OD value. Concerning apoptosis detection, the control group had the lowest apoptosis rate. The highest apoptosis rates were found in the MW167 + OGD, the OGD, and then the G-CSF + OGD groups.ConclusionsThe blocking of the Notch pathway can attenuate the G-CSF effects, whereas the G-CSF overexpression can activate the Notch pathway to resist the effects of oxygen-glucose deprivation.


2021 ◽  
Vol 17 ◽  
Author(s):  
Mateusz Puchala ◽  
Andrzej Rydzewski ◽  
Ilona Kowalik ◽  
Małgorzata Wisłowska

Background: GPA is a necrotizing inflammation of the small vessels with granulomas. Kidney involvement deteriorated its prognosis. Objective: Comparison of GPA patients with kidney (KI) and without kidney involvement (nKI). Material and methods: We conducted a cross-sectional study of 50 consecutive adult GPA patients, 25 KI from Nephrology and 25 nKI from Rheumatology Department of Central Clinical Hospital Ministry of Interior in Warsaw. We analyzed clinical features, organ involvement, laboratory, serological, imaging, histopathological data, BVAS, treatment. Results: The mean age of KI patients was statistically older then nKI (67.3±9.5 vs 55.1±15.9, p=0.002). Generalized, severe, resistance disease was observed respectively in 92% vs 44%, p<0.001. The number of red blood cells (3.47 vs 4.41T/l, p<0.001), hemoglobin (10.0 vs 12.9g/dl, p<0.001) was lower in KI, higher mean serum creatinine (3.95 vs. 0.89mg/dl, p<0.001), lower GFR (20.1 vs. 79.3, p<0.001), higher CRP (median: 43.4 vs 2.0mg/l, p<0.001), BVAS (16.6±4.4 vs 10.1±6.2, p<0.001), c-ANCA (median: 119.0 vs 15.2CU, p=0.017). Nodules in 28% KI, in 4% nKI (p=0.048) in chest X-ray, infiltration in 43.5% KI, in 15% nKI (p=0.042) in HRCT were observed. Skin granulomas were found in 61.5% nKI vs 18.2% KI, (p=0.047). Renal biopsy revealed in KI patients focal segmental glomerulonephritis in 11.8%, crescentic glomerulonephritis in 17.6%, pauci-immune crescentic glomerulonephritis in 70.6%. Conclusions: In patients with KI more frequently we found generalized, severe, resistant GPA, higher BVAS in comparison in patients without KI. The results of laboratory parameters, were worse in patients with KI. Aggressive immunosuppressive treatment is often used in KI group.


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.


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