| 1. |
- Celik, Selvi, et al.
(författare)
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Antisense regulation of atrial natriuretic peptide expression
- 2019
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Ingår i: JCI Insight. - : American Society for Clinical Investigation. - 2379-3708. ; 4:19
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Tidskriftsartikel (refereegranskat)abstract
- The cardiac hormone atrial natriuretic peptide (ANP) is a central regulator of blood volume and a therapeutic target in hypertension and heart failure. Enhanced ANP activity in such conditions through inhibition of the degradative enzyme neprilysin has shown clinical efficacy but is complicated by consequences of simultaneous accumulation of a heterogeneous array of other hormones. Targets for specific ANP enhancement have not been available. Here, we describe a cis-acting antisense transcript (NPPA-AS1), which negatively regulates ANP expression in human cardiomyocytes. We show that NPPA-AS1 regulates ANP expression via facilitating NPPA repressor RE1-silencing transcription factor (REST) binding to its promoter, rather than forming an RNA duplex with ANP mRNA. Expression of ANP mRNA and NPPA-AS1 was increased and correlated in isolated strained human cardiomyocytes and in hearts from patients with advanced heart failure. Further, inhibition of NPPA-AS1 in vitro and in vivo resulted in increased myocardial expression of ANP, increased circulating ANP, increased renal cGMP, and lower blood pressure. The effects of NPPA-AS1 inhibition on NPPA expression in human cardiomyocytes were further marked under cell-strain conditions. Collectively, these results implicate the antisense transcript NPPA-AS1 as part of a physiologic self-regulatory ANP circuit and a viable target for specific ANP augmentation.
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| 2. |
- Celik, Selvi, et al.
(författare)
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Functional Screening Identifies MicroRNA Regulators of Corin Activity and Atrial Natriuretic Peptide Biogenesis
- 2019
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Ingår i: Molecular and Cellular Biology. - 0270-7306. ; 39:23
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Tidskriftsartikel (refereegranskat)abstract
- Atrial natriuretic peptide (ANP) represents an attractive therapeutic target in hypertension and heart failure. The biologically active form of ANP is produced by the cardiac serine protease corin, and modulation of its activity might therefore represent a novel approach for ANP augmentation. MicroRNAs (miRNAs) are pervasive regulators of gene expression, but their potential role in regulating corin activity has not been elucidated. Our aim was to systematically identify and characterize miRNA regulators of corin activity in human cardiomyocytes. An assay for measuring serine protease activity in human induced pluripotent stem cell (iPS)-derived cardiomyocytes was used to perform a comprehensive screening of miRNA family inhibitors (n = 42). miRNA 1-3p (miR-1-3p) was identified as a potent inhibitor of corin activity. The interaction between miR-1-3p and a specific target site in the CORIN 3' untranslated region (3' UTR) was confirmed through argonaute 2 (AGO2)-RNA immunoprecipitation and reporter assays. Inhibition of miR-1-3p resulted in upregulation of CORIN gene and protein expression, as well as a concomitant increase in extracellular ANP. Additionally, miR-1-3p was found to interact with and inhibit the expression of several transcriptional activators of ANP gene expression. In conclusion, we have identified a novel regulator of corin activity and ANP biogenesis in human cardiomyocytes that might be of potential future therapeutic utility.
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| 3. |
- Ekman, Mari, et al.
(författare)
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Association of muscarinic M(3) receptors and Kir6.1 with caveolae in human detrusor muscle.
- 2012
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Ingår i: European Journal of Pharmacology. - : Elsevier BV. - 1879-0712 .- 0014-2999. ; 683:1-3, s. 238-245
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Tidskriftsartikel (refereegranskat)abstract
- Caveolae are 50-100nm large membrane invaginations that play a role in cellular signaling. The aim of the present study was to assess whether muscarinic M(3) receptors and the K(ATP) channel subunit Kir6.1 are associated with human detrusor caveolae, and to pharmacologically assess the relevance of this organization for contractility. Detrusor strips were dissected and used in ultrastructural, biochemical and mechanical studies. Caveolae were manipulated by cholesterol desorption using mβcd (methyl-β-cyclodextrin). Mβcd disrupted caveolae and caused a cholesterol-dependent ~3-fold rightward shift of the concentration-response curve for the muscarinic receptor agonist carbachol. The effect of mβcd was inhibited by the K(ATP) blockers glibenclamide, repaglinide and PNU-37883, and it was mimicked by the K(ATP) activator levcromakalim. Immunoelectron microscopy showed muscarinic M(3) receptors and Kir6.1 to be enriched in caveolae. In conclusion, pharmacological K(ATP) channel inhibition antagonizes the effect of caveolae disruption on muscarinic contractility in the human detrusor, and the K(ATP) channel subunit Kir6.1 co-localizes with M(3) receptors in caveolae.
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| 4. |
- Persson, Helena, et al.
(författare)
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A common idiotype in IgE and its relation to recognition of the grass pollen allergen Phl p 2.
- 2008
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Ingår i: Molecular Immunology. - : Elsevier BV. - 1872-9142 .- 0161-5890. ; 45:9, s. 2715-2720
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Tidskriftsartikel (refereegranskat)abstract
- The variable regions of allergen-specific IgE, the isotype mediating allergic responses, are poorly defined to date. In this study we define the character of human antibody binding sites recognizing Phl p 2, a major allergen from timothy grass pollen. Independently raised specificities developed by phage display technology tended to have common sequence motifs (idiotypes), such as IGHV4-31 germline gene origin and heavy chain complementarity-determining region (CDR) 3 length and sequence. They also combined with highly related light chain sequences. Such heavy chain variable domain-encoding transcripts have also been found in the IgE-encoding transcriptome of yet other grass pollen allergic subjects. Altogether these data argue that a common idiotype is used to establish specific antibodies with a potential to mediate allergic responses to Phl p 2. Such a restriction may contribute to the limited molecular diversity observed in some IgE populations.
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| 5. |
- Persson, Helena, et al.
(författare)
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Delineating the specificity of an IgE-encoding transcriptome.
- 2007
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 1097-6825 .- 0091-6749. ; 120:5, s. 1186-1192
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Tidskriftsartikel (refereegranskat)abstract
- Background Although much is known about the reactivity of polyclonal populations of antibodies targeting the wide array of allergens produced by timothy (Phleum pratense) and other grass species, little is known about the finer details at the level of individual antibody specificities. Objective We sought to investigate the IgE repertoire as it occurs in a patient with grass pollen allergy. Methods For this purpose, a human IgE library was used, constructed from peripheral blood B cells of an individual with timothy allergy. The library was screened by using phage display against a panel of 6 timothy allergens (Phl p 1, Phl p 2, Phl p 4, Phl p 5, Phl p 6, and Phl p 11). Results Highly diverse antibody fragments with respect to gene usage were identified. The binders were specific for their respective target antigen, except for clones selected on Phl p 6 that also recognized Phl p 5, most likely reflecting the high sequence homology between these allergens. Interestingly, by using this approach, we were able to determine the specificity of more than 25% of all IgE-producing transcripts in this individual with allergy. Conclusion The human IgE repertoire is produced by a limited number of highly related B-cell clones and as such is restricted in its recognition of a limited number of antigens. Clinical implications Human allergen-specific antibodies can, by defining the specificity of IgE responses, aid in the development of allergy vaccines or even by themselves be used in passive immunotherapy.
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| 6. |
- Pimpalwar, Neha, et al.
(författare)
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Analysis of genetic variant associated with heart failure mortality implicates thymic stromal lymphopoietin as mediator of strain-induced myocardial fibroblast-mast cell crosstalk and fibrosis
- 2024
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Ingår i: FASEB JOURNAL. - 0892-6638 .- 1530-6860. ; 38:4
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Tidskriftsartikel (refereegranskat)abstract
- Heart failure (HF) is a leading cause of death and disability globally. Heritable factors and the extent and pattern of myocardial fibrosis are important determinants of outcomes in patients with HF. In a genome-wide association study of mortality in HF, we recently identified a genetic polymorphism on chromosome 5q22 associated with HF mortality. Here, we sought to study the mechanisms by which this variant may influence myocardial disease processes. We find that the risk allele is located in an enhancer motif upstream of the TSLP gene (encoding thymic stromal lymphopoietin), conferring increased binding of the transcription factor nescient helix-loop helix 1 (NHLH1) and increased TSLP expression in human heart. Further, we find that increased strain of primary human myocardial fibroblasts results in increased TSLP expression and that the TSLP receptor is expressed in myocardial mast cells in human single nuclei RNA sequence data. Finally, we show that TSLP overexpression induces increased transforming growth factor beta expression in myocardial mast cells and tissue fibrosis. Collectively, our findings based on follow-up of a human genetic finding implicate a novel pathway in myocardial tissue homeostasis and remodeling. The extent and patterning of myocardial fibrosis are important determinants of outcome in heart disease. Here, we report that increased strain in myocardial cells results in increased expression of thymic stromal lymphopoietin (TSLP). Furthermore, increased TSLP expression, modulated by the transcription factor nescient helix-loop helix 1 (NHLH1), induces increased transforming growth factor beta (TGF-beta) expression in myocardial mast cells and tissue fibrosis. Our findings thus implicate a novel pathway in myocardial tissue homeostasis and putative therapeutic target to prevent fibrosis.image
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| 7. |
- Sadegh, Mardjaneh Karbalaei, et al.
(författare)
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Biomechanical properties and innervation of the female caveolin-1-deficient detrusor.
- 2011
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Ingår i: British Journal of Pharmacology. - : Wiley. - 1476-5381 .- 0007-1188. ; Dec, s. 1156-1170
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: Caveolin-1-deficiency is associated with substantial urogenital alterations. Here, a mechanical, histological and biochemical characterization of female detrusors from wild-type (WT) and caveolin-1-deficient (KO) mice was made to increase the understanding of detrusor changes caused by lack of caveolae. Experimental approach: Length-tension relationships were generated, and we recorded responses to electrical field stimulation (EFS), the muscarinic receptor agonist carbachol, and the purinoceptor agonist ATP. Tyrosine nitration and the contents of caveolin-1, cavin-1, muscarinic M(3) receptors, phospholipase C(β1) (PLC(β1) ), muscle-specific kinase (MuSK), and L-type Ca(2+) -channels were determined by immunoblotting. Innervation was assessed by immunohistochemistry. Key results: Bladder to body weight ratio was not changed, nor was there any change in the optimum circumference for force development. Depolarization- and ATP-induced stress was reduced, as was carbachol-induced stress between 0.1 and 3 µM, but the supramaximal relative (% K(+) ) response to carbachol was increased, as was M(3) expression. The scopolamine-sensitive component of the EFS-response was impaired, and yet bladder nerves contained little caveolin-1. The density of cholinergic nerves was unchanged, whereas CART- and CGRP-positive nerves were reduced. Immunoblotting revealed loss of MuSK. Conclusions and implications: Ablation of caveolae in the female detrusor leads to generalised impairment of contractility, ruling out prostate hypertrophy as a contributing factor. Cholinergic neuroeffector transmission is impaired without conspicuous changes in the density of cholinergic nerves or morphology of their terminals, but correlating with reduced expression of MuSK.
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| 8. |
- Sadegh, Mardjaneh Karbalaei, et al.
(författare)
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Deletion of dicer in smooth muscle affects voiding pattern and reduces detrusor contractility and neuroeffector transmission.
- 2012
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- MicroRNAs have emerged as important regulators of smooth muscle phenotype and may play important roles in pathogenesis of various smooth muscle related disease states. The aim of this study was to investigate the role of miRNAs for urinary bladder function. We used an inducible and smooth muscle specific Dicer knockout (KO) mouse which resulted in significantly reduced levels of miRNAs, including miR-145, miR-143, miR-22, miR125b-5p and miR-27a, from detrusor preparations without mucosa. Deletion of Dicer resulted in a disturbed micturition pattern in vivo and reduced depolarization-induced pressure development in the isolated detrusor. Furthermore, electrical field stimulation revealed a decreased cholinergic but maintained purinergic component of neurogenic activation in Dicer KO bladder strips. The ultrastructure of detrusor smooth muscle cells was well maintained, and the density of nerve terminals was similar. Western blotting demonstrated reduced contents of calponin and desmin. Smooth muscle α-actin, SM22α and myocardin were unchanged. Activation of strips with exogenous agonists showed that depolarization-induced contraction was preferentially reduced; ATP- and calyculin A-induced contractions were unchanged. Quantitative real time PCR and western blotting demonstrated reduced expression of Cav1.2 (Cacna1c). It is concluded that smooth muscle miRNAs play an important role for detrusor contractility and voiding pattern of unrestrained mice. This is mediated in part via effects on expression of smooth muscle differentiation markers and L-type Ca(2+) channels in the detrusor.
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