Control of Pathological Cardiac Hypertrophy by Transcriptional Corepressor IRF2BP2 (Interferon Regulatory Factor-2 Binding Protein 2)

ABSTRACTObjectivesTo investigate the functional consequences of the single nucleotide polymorphism rs4648889 in a putative enhancer upstream of the RUNX3 promoter strongly associated with ankylosing spondylitis (AS).MethodsThe effects of rs4648889 on transcription factor (TF) binding were tested by DNA pull-down and quantitative mass spectrometry. The results were validated by electrophoretic mobility gel shift assays (EMSA), Western blot (WB) analysis of the pulled-down eluates, and chromatin immuno-precipitation (ChIP)-qPCR.ResultsSeveral TFs showed differential allelic binding to a 50bp DNA probe spanning rs4648889. Binding was increased to the AS-risk A allele for IKZF3 (aiolos) in nuclear extracts from CD8+ T-cells (3.7-fold, p<0.03) and several components of the NUcleosome Remodeling Deacetylase (NuRD) complex, including Chromodomain-Helicase-DNA-binding protein 4 (3.6-fold, p<0.05) and Retinoblastoma-Binding Protein 4 (4.1-fold, p<0.02). In contrast, binding of interferon regulatory factor (IRF) 5 was increased to the AS-protective G allele. These results were confirmed by EMSA, WB and ChIP-qPCR.ConclusionsThe association of AS with rs4648889 most likely results from its influence on the binding of this enhancer-like region to TFs, including IRF5, IKZF3 and members of the NuRD complex. Further investigation of these factors and RUNX3-related pathways may reveal important new therapeutic possibilities in AS.

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A gene therapeutic approach to inhibit calcium and integrin binding protein 1 ameliorates maladaptive remodelling in pressure overload

Cardiovascular Research ◽

10.1093/cvr/cvy154 ◽

2018 ◽

Vol 115 (1) ◽

pp. 71-82 ◽

Cited By ~ 5

Author(s):

Andrea Grund ◽

Malgorzata Szaroszyk ◽

Janina K Döppner ◽

Mona Malek Mohammadi ◽

Badder Kattih ◽

...

Keyword(s):

Heart Failure ◽

Cardiac Hypertrophy ◽

Cardiac Function ◽

Binding Protein ◽

Treatment Strategies ◽

Pressure Overload ◽

Cellular Growth ◽

Neonatal Rat ◽

Rat Cardiomyocytes ◽

Pathological Cardiac Hypertrophy

Abstract Aims Chronic heart failure is becoming increasingly prevalent and is still associated with a high mortality rate. Myocardial hypertrophy and fibrosis drive cardiac remodelling and heart failure, but they are not sufficiently inhibited by current treatment strategies. Furthermore, despite increasing knowledge on cardiomyocyte intracellular signalling proteins inducing pathological hypertrophy, therapeutic approaches to target these molecules are currently unavailable. In this study, we aimed to establish and test a therapeutic tool to counteract the 22 kDa calcium and integrin binding protein (CIB) 1, which we have previously identified as nodal regulator of pathological cardiac hypertrophy and as activator of the maladaptive calcineurin/NFAT axis. Methods and results Among three different sequences, we selected a shRNA construct (shCIB1) to specifically down-regulate CIB1 by 50% upon adenoviral overexpression in neonatal rat cardiomyocytes (NRCM), and upon overexpression by an adeno-associated-virus (AAV) 9 vector in mouse hearts. Overexpression of shCIB1 in NRCM markedly reduced cellular growth, improved contractility of bioartificial cardiac tissue and reduced calcineurin/NFAT activation in response to hypertrophic stimulation. In mice, administration of AAV-shCIB1 strongly ameliorated eccentric cardiac hypertrophy and cardiac dysfunction during 2 weeks of pressure overload by transverse aortic constriction (TAC). Ultrastructural and molecular analyses revealed markedly reduced myocardial fibrosis, inhibition of hypertrophy associated gene expression and calcineurin/NFAT as well as ERK MAP kinase activation after TAC in AAV-shCIB1 vs. AAV-shControl treated mice. During long-term exposure to pressure overload for 10 weeks, AAV-shCIB1 treatment maintained its anti-hypertrophic and anti-fibrotic effects, but cardiac function was no longer improved vs. AAV-shControl treatment, most likely resulting from a reduction in myocardial angiogenesis upon downregulation of CIB1. Conclusions Inhibition of CIB1 by a shRNA-mediated gene therapy potently inhibits pathological cardiac hypertrophy and fibrosis during pressure overload. While cardiac function is initially improved by shCIB1, this cannot be kept up during persisting overload.

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Interferon regulatory factor 2 binding protein 2b regulates neutrophil versus macrophage fate during zebrafish definitive myelopoiesis

Haematologica ◽

10.3324/haematol.2019.217596 ◽

2019 ◽

Vol 105 (2) ◽

pp. 325-337

Author(s):

Luxiang Wang ◽

Shuo Gao ◽

Haihong Wang ◽

Chang Xue ◽

Xiaohui Liu ◽

...

Keyword(s):

Binding Protein ◽

Interferon Regulatory Factor ◽

Regulatory Factor

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Interferon consensus sequence-binding protein, a member of the interferon regulatory factor family, suppresses interferon-induced gene transcription.

Molecular and Cellular Biology ◽

10.1128/mcb.13.1.588 ◽

1993 ◽

Vol 13 (1) ◽

pp. 588-599 ◽

Cited By ~ 125

Author(s):

N Nelson ◽

M S Marks ◽

P H Driggers ◽

K Ozato

Keyword(s):

Major Histocompatibility Complex ◽

Retinoic Acid ◽

Major Histocompatibility Complex Class ◽

Binding Protein ◽

Consensus Sequence ◽

Interferon Regulatory Factor ◽

Chloramphenicol Acetyltransferase ◽

Complex Class ◽

Regulatory Factor ◽

Histocompatibility Complex

We previously isolated a cDNA clone encoding interferon consensus sequence-binding protein (ICSBP), a member of the interferon regulatory factor (IRF) family, that binds to the interferon (IFN)-stimulated response element (ISRE) of many IFN-regulated genes. In this investigation, we studied the functional role of ICSBP by transient cotransfection of ICSBP cDNA with IFN-responsive reporter genes into the human embryonal carcinoma cell line N-Tera2. These cells were shown not to express ICSBP or IRF-2, thus allowing functional analysis of transfected cDNAs. Cotransfection of ICSBP into cells treated with retinoic acid or any of the IFNs (alpha, beta, or gamma) repressed expression of a chloramphenicol acetyltransferase reporter driven by the major histocompatibility complex class I gene promoter. Similarly, ICSBP repressed expression of chloramphenicol acetyltransferase reporters driven by the ISREs of the 2'-5' oligoadenylate synthetase, guanylate-binding protein, and ISG-15 genes in IFN-treated cells. The repression was dependent on the presence of the ISRE in the reporter. Deletion analysis showed that the putative N-terminal DNA binding domain of ICSBP by itself is capable of mediating the repression. Using the same cotransfection conditions as for ICSBP, a similar repression of these reporters was observed with IRF-2. Finally, ICSBP repressed the IRF-1-mediated induction of major histocompatibility complex class I and IFN-beta reporters in the absence of IFN or retinoic acid. Taken together, these results suggest that ICSBP is a negative regulatory factor capable of repressing transcription of target genes induced by IFN, retinoic acid, or IRF-1.

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