| 1. |
- Hjelmgren, Ola, et al.
(författare)
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Identification of Vascularised Carotid Plaques Using a Standardised and Reproducible Technique to Measure Ultrasound Contrast Uptake
- 2013
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Ingår i: European Journal of Vascular and Endovascular Surgery. - : Elsevier BV. - 1078-5884 .- 1532-2165. ; 46:1, s. 21-28
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Contrast-enhanced ultrasonography (CEUS) has been used to assess the vascularisation of carotid plaques. Our aim was to develop and validate a standardised semi-automated method for CEUS examination of plaques, and test if the technique could be used to identify vulnerable plaques. Methods: Study participants were a mixed population of symptomatic and asymptomatic subjects, selected if they had a plaque with height >2.5 mm and <10% acoustic shadowing. Participants received a bolus of ultrasound contrast agent and a 90-s cine-loop was captured. A Contrast Quantification Program (CQP) was developed and trained to identify extent of contrast uptake after motion correction and application of a noise reduction algorithm. The technique was validated by comparing CQP values with visual assessment of contrast uptake. CQP values were also compared with plaque echogenicity and history of clinical events. Results: CQP values correlated with a visual, 5-scale classification of contrast uptake by two blinded, experienced sonographers. Repeated contrast injections showed high reproducibility. Participants with a history of ipsilateral stroke/TIA had significantly higher CQP values than asymptomatic participants. Conclusion: We present a reproducible, semi-automatic method to identify vascularisation of carotid plaques, which could be used in prospective studies to determine the clinical value of plaque vascularisation. (C) 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.
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| 2. |
- Lind, Simon, 1993, et al.
(författare)
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Interdependent allosteric free fatty acid receptor 2 modulators synergistically induce functional selective activation and desensitization in neutrophils
- 2020
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Ingår i: Biochimica Et Biophysica Acta-Molecular Cell Research. - : Elsevier BV. - 0167-4889. ; 1867:6
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Tidskriftsartikel (refereegranskat)abstract
- The non-activating allosteric modulator AZ1729, specific for free fatty acid receptor 2 (FFAR2), transfers the orthosteric FFAR2 agonists propionate and the P2Y(2)R specific agonist ATP into activating ligands that trigger an assembly of the neutrophil superoxide generating NADPH-oxidase. The homologous priming effect on the propionate response and the heterologous receptor cross-talk sensitized ATP response mediated by AZ1729 are functional characteristics shared with Cmp58, another non-activating allosteric FFAR2 modulator. In addition, AZ1729 also turned Cmp58 into a potent activator of the superoxide generating neutrophil NADPH-oxidase, and in agreement with the allosteric modulation concept, the effect was reciprocal in that Cmp58 turned AZ1729 into a potent activating allosteric agonist. The activation signals down-stream of FFAR2 when stimulated by the two interdependent allosteric modulators were biased in that, unlike for orthosteric agonists, the two complementary modulators together triggered an activation of the NADPH-oxidase, but not any transient rise in the cytosolic concentration of free calcium ions (Ca2+). Furthermore, following AZ1729/Cmp58 activation, the signaling by the desensitized FFAR2s was functionally selective in that the orthosteric agonist propionate could still induce a transient rise in intracellular Ca2+. The novel neutrophil activation and receptor down-stream signaling pattern mediated by the two cross-sensitizing allosteric FFAR2 modulators represent a new regulatory mechanism that controls receptor signaling.
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| 3. |
- Mårtensson, Jonas, et al.
(författare)
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Neutrophil priming that turns natural FFA2R agonists into potent activators of the superoxide generating NADPH-oxidase
- 2018
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Ingår i: Journal of leukocyte biology. - : Oxford University Press (OUP). - 0741-5400 .- 1938-3673. ; 104:6, s. 1117-1132
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Tidskriftsartikel (refereegranskat)abstract
- Acetate, an agonist for the free fatty acid receptor 2 (FFA2R/GPR43), triggers an increase in the cytosolic concentration of free Ca2+ in neutrophils without any assembly of the superoxide generating NADPH-oxidase. We show that the phenylacetamide compound 58 (Cmp 58; (S)-2-(4-chlorophenyl)-3,3-dimethyl-N-(5-phenylthiazol-2-yl)butanamide), lacking a direct activating effect on neutrophils, acts as a positive FFA2R modulator that turns acetate into a potent activating agonist that triggers an assembly of the NADPH-oxidase. The NADPH-oxidase activity could be further increased in neutrophils treated with the pro-inflammatory cytokine TNF-alpha. Many neutrophil chemoattractant receptors are stored in secretory organelles but no FFA2R mobilization was induced in neutrophils treated with TNF-alpha. The receptor selectivity was demonstrated through the inhibition of the neutrophil response induced by the combined action of acetate and Cmp 58 by the FFA2R antagonist CATPB. Receptor modulators that positively co-operate with natural FFA2R agonists and prime neutrophils in their response to such agonists, may serve as good tools for further unraveling the physiological functions of FFA2R and its involvement in various diseases. In this study, we show that neutrophils primed with a presumed allosteric FFA2R modulator produce increased amounts of reactive oxygen species when activated by receptor specific agonists.
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