| 1. |
- Battistella, Roberta, et al.
(författare)
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Not All Lectins Are Equally Suitable for Labeling Rodent Vasculature
- 2021
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 22:21
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Tidskriftsartikel (refereegranskat)abstract
- The vascular system is vital for all tissues and the interest in its visualization spans many fields. A number of different plant-derived lectins are used for detection of vasculature; however, studies performing direct comparison of the labeling efficacy of different lectins and techniques are lacking. In this study, we compared the labeling efficacy of three lectins: Griffonia simplicifolia isolectin B4 (IB4); wheat germ agglutinin (WGA), and Lycopersicon esculentum agglutinin (LEA). The LEA lectin was identified as being far superior to the IB4 and WGA lectins in histological labeling of blood vessels in brain sections. A similar signal-to-noise ratio was achieved with high concentrations of the WGA lectin injected during intracardial perfusion. Lectins were also suitable for labeling vasculature in other tissues, including spinal cord, dura mater, heart, skeletal muscle, kidney, and liver tissues. In uninjured tissues, the LEA lectin was as accurate as the Tie2-eGFP reporter mice and GLUT-1 immunohistochemistry for labeling the cerebral vasculature, validating its specificity and sensitivity. However, in pathological situations, e.g., in stroke, the sensitivity of the LEA lectin decreases dramatically, limiting its applicability in such studies. This work can be used for selecting the type of lectin and labeling method for various tissues.
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| 2. |
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| 3. |
- Don-Doncow, Nicholas, et al.
(författare)
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Simvastatin therapy attenuates memory deficits that associate with brain monocyte infiltration in chronic hypercholesterolemia
- 2021
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Ingår i: npj Aging and Mechanisms of Disease. - : Springer Science and Business Media LLC. - 2056-3973. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Evidence associates cardiovascular risk factors with unfavorable systemic and neuro-inflammation and cognitive decline in the elderly. Cardiovascular therapeutics (e.g., statins and anti-hypertensives) possess immune-modulatory functions in parallel to their cholesterol- or blood pressure (BP)-lowering properties. How their ability to modify immune responses affects cognitive function is unknown. Here, we examined the effect of chronic hypercholesterolemia on inflammation and memory function in Apolipoprotein E (ApoE) knockout mice and normocholesterolemic wild-type mice. Chronic hypercholesterolemia that was accompanied by moderate blood pressure elevations associated with apparent immune system activation characterized by increases in circulating pro-inflammatory Ly6Chi monocytes in ApoE-/- mice. The persistent low-grade immune activation that is associated with chronic hypercholesterolemia facilitates the infiltration of pro-inflammatory Ly6Chi monocytes into the brain of aged ApoE-/- but not wild-type mice, and links to memory dysfunction. Therapeutic cholesterol-lowering through simvastatin reduced systemic and neuro-inflammation, and the occurrence of memory deficits in aged ApoE-/- mice with chronic hypercholesterolemia. BP-lowering therapy alone (i.e., hydralazine) attenuated some neuro-inflammatory signatures but not the occurrence of memory deficits. Our study suggests a link between chronic hypercholesterolemia, myeloid cell activation and neuro-inflammation with memory impairment and encourages cholesterol-lowering therapy as safe strategy to control hypercholesterolemia-associated memory decline during ageing.
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| 4. |
- Don-Doncow, Nicholas, et al.
(författare)
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T-Cell Accumulation in the Hypertensive Brain: A Role for Sphingosine-1-Phosphate-Mediated Chemotaxis.
- 2019
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 20:3, s. 1-14
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Tidskriftsartikel (refereegranskat)abstract
- Hypertension is considered the major modifiable risk factor for the development of cognitive impairment. Because increased blood pressure is often accompanied by an activation of the immune system, the concept of neuro-inflammation gained increasing attention in the field of hypertension-associated neurodegeneration. Particularly, hypertension-associated elevated circulating T-lymphocyte populations and target organ damage spurred the interest to understanding mechanisms leading to inflammation-associated brain damage during hypertension. The present study describes sphingosine-1-phosphate (S1P) as major contributor to T-cell chemotaxis to the brain during hypertension-associated neuro-inflammation and cognitive impairment. Using Western blotting, flow cytometry and mass spectrometry approaches, we show that hypertension stimulates a sphingosine kinase 1 (SphK1)-dependent increase of cerebral S1P concentrations in a mouse model of angiotensin II (AngII)-induced hypertension. The development of a distinct S1P gradient between circulating blood and brain tissue associates to elevated CD3+ T-cell numbers in the brain. Inhibition of S1P1-guided T-cell chemotaxis with the S1P receptor modulator FTY720 protects from augmentation of brain CD3 expression and the development of memory deficits in hypertensive WT mice. In conclusion, our data highlight a new approach to the understanding of hypertension-associated inflammation in degenerative processes of the brain during disease progression.
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| 5. |
- Don-Doncow, Nicholas, et al.
(författare)
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The emerging alliance of sphingosine-1-phosphate signaling and immune cells: from basic mechanisms to implications in hypertension.
- 2019
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Ingår i: British Journal of Pharmacology. - : Wiley. - 1476-5381 .- 0007-1188. ; 176:12, s. 1989-2001
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Forskningsöversikt (refereegranskat)abstract
- The immune system plays a considerable role in hypertension. In particular, T-lymphocytes are recognized as important players in its pathogenesis. Despite substantial experimental efforts, the molecular mechanisms underlying the nature of T-cell activation contributing to an onset of hypertension or disease perpetuation are still elusive. Amongst other cell types, lymphocytes express distinct profiles of GPCRs for sphingosine-1-phosphate (S1P) – a bioactive phospholipid that is involved in many critical cell processes and most importantly majorly regulates T-cell development, lymphocyte recirculation, tissue-homing patterns and chemotactic responses. Recent findings have revealed a key role for S1P chemotaxis and T-cell mobilization for the onset of experimental hypertension, and elevated circulating S1P levels have been linked to several inflammation-associated diseases including hypertension in patients. In this article, we review the recent progress towards understanding how S1P and its receptors regulate immune cell trafficking and function and its potential relevance for the pathophysiology of hypertension. Linked Articles: This article is part of a themed section on Immune Targets in Hypertension.
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| 6. |
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| 7. |
- Ekroos, Johan, et al.
(författare)
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Declines amongst breeding Eider Somateria mollissima numbers in the Baltic/Wadden Sea flyway
- 2012
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Ingår i: Ornis Fennica. - 0030-5685. ; 89:2, s. 81-90
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Tidskriftsartikel (refereegranskat)abstract
- We report on the status of the Baltic/Wadden Sea flyway Eider population based on trends in breeding and wintering numbers throughout the region, supplemented by changes in the sex ratio and proportion of young Eiders as monitored in the Danish hunting bag. At the flyway scale, total numbers of breeding pairs decreased by 48% during 2000-2009, after relatively stable breeding numbers in 1991-2000. The majority of the population nest in Finland and Sweden, where the number of breeding pairs has halved over the same period. After initial declines in winter numbers between 1991 and 2000, during 2000-2009, national wintering numbers increased in the Baltic Sea, but decreased in the Wadden Sea. The annual proportion of adult females in the Danish hunting bag data decreased from ca. 45% (1982) to ca. 25% (2009) and simultaneously the proportion of first-winter birds fell from ca. 70% to ca. 30%, indicating dramatic structural changes in the Danish wintering numbers. These results suggest that the total flyway population will experience further declines, unless productivity increases and the factors responsible for decreasing adult female survival are identified and ameliorated. We discuss potential population drivers and present some recommendations for improved flyway-level monitoring and management of Eiders.
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| 8. |
- Jujic, Amra, et al.
(författare)
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Plasma Galectin-4 Levels Are Increased after Stroke in Mice and Humans
- 2023
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Ingår i: International Journal of Molecular Sciences. - 1661-6596 .- 1422-0067. ; 24:12
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Tidskriftsartikel (refereegranskat)abstract
- Epidemiological studies have associated plasma galectin-4 (Gal-4) levels with prevalent and incident diabetes, and with an increased risk of coronary artery disease. To date, data regarding possible associations between plasma Gal-4 and stroke are lacking. Using linear and logistic regression analyses, we tested Gal-4 association with prevalent stroke in a population-based cohort. Additionally, in mice fed a high-fat diet (HFD), we investigated whether plasma Gal-4 increases in response to ischemic stroke. Plasma Gal-4 was higher in subjects with prevalent ischemic stroke, and was associated with prevalent ischemic stroke (odds ratio 1.52; 95% confidence interval 1.01-2.30; p = 0.048) adjusted for age, sex, and covariates of cardiometabolic health. Plasma Gal-4 increased after experimental stroke in both controls and HFD-fed mice. HFD exposure was devoid of impact on Gal-4 levels. This study demonstrates higher plasma Gal-4 levels in both experimental stroke and in humans that experienced ischemic stroke.
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| 9. |
- Jujic, Amra, et al.
(författare)
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Plasma S1P (Sphingosine-1-Phosphate) Links to Hypertension and Biomarkers of Inflammation and Cardiovascular Disease : Findings From a Translational Investigation
- 2021
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Ingår i: Hypertension. - 1524-4563. ; 78:1, s. 195-209
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Tidskriftsartikel (refereegranskat)abstract
- S1P (Sphingosine-1-phosphate) is an important regulator of immune cell trafficking and vascular dysfunction contributing to the development and progression of overt hypertension. Although targeting S1P signaling revealed therapeutic potential in different experimental hypertension studies, validations of S1P-blood pressure (BP) associations in humans are lacking. In a translational approach, we explored the associations between plasma S1P and BP in a family based study cohort (MOS [Malmö Offspring Study]; N=1046) and in a longitudinally conducted murine hypertension cohort. In MOS, linear multivariate regression analyses showed that plasma S1P associates with increased systolic BP (β=1.06, P=0.015). Study subjects with systolic BP ≥140 mm Hg presented with significantly higher S1P plasma concentrations compared with subjects with BP <120 mm Hg independent of age and sex. The S1P-BP association was validated in a murine model where plasma S1P increased with systolic BP (r=0.7018, R2=0.4925; P<0.0001). In a subsample of MOS (N=444), proteomic profiling for markers of inflammation, metabolism, and cardiovascular disease using Proximity Extension Assays revealed multiple significant S1P associations, some of them with marked sex-specificity. In vitro and ex vivo validation of identified S1P associations disclosed augmented expression of different vascular dysfunction and inflammation markers in response to S1P. Our translational findings show a link between plasma S1P and systolic BP as well as several inflammation and cardiovascular disease markers and suggest S1P's biomarker potential. This encourages further studies to investigate its predictive capacity for hypertensive disease or the therapeutic potential of its signaling axis.
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| 10. |
- Lidington, Darcy, et al.
(författare)
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CFTR Therapeutics Normalize Cerebral Perfusion Deficits in Mouse Models of Heart Failure and Subarachnoid Hemorrhage
- 2019
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Ingår i: JACC: Basic to Translational Science. - : Elsevier BV. - 2452-302X. ; 4:8, s. 940-958
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Tidskriftsartikel (refereegranskat)abstract
- Heart failure (HF) and subarachnoid hemorrhage (SAH) chronically reduce cerebral perfusion, which negatively affects clinical outcome. This work demonstrates a strong relationship between cerebral artery cystic fibrosis transmembrane conductance regulator (CFTR) expression and altered cerebrovascular reactivity in HF and SAH. In HF and SAH, CFTR corrector compounds (C18 or lumacaftor) normalize pathological alterations in cerebral artery CFTR expression, vascular reactivity, and cerebral perfusion, without affecting systemic hemodynamic parameters. This normalization correlates with reduced neuronal injury. Therefore, CFTR therapeutics have emerged as valuable clinical tools to manage cerebrovascular dysfunction, impaired cerebral perfusion, and neuronal injury.
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| 11. |
- Malm Tillgren, Sofia, et al.
(författare)
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C57Bl/6N mice have an attenuated lung inflammatory response to dsRNA compared to C57Bl/6J and BALB/c mice
- 2023
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Ingår i: Journal of Inflammation. - : Springer Science and Business Media LLC. - 1476-9255. ; 20, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Lower respiratory infections caused by ssRNA viruses are a major health burden globally. Translational mouse models are a valuable tool for medical research, including research on respiratory viral infections. In in vivo mouse models, synthetic dsRNA can be used as a surrogate for ssRNA virus replication. However, studies investigating how genetic background of mice impacts the murine lung inflammatory response to dsRNA is lacking. Hence, we have compared lung immunological responses of BALB/c, C57Bl/6N and C57Bl/6J mice to synthetic dsRNA.METHODS: dsRNA was administered intranasally to BALB/c, C57Bl/6N and C57Bl/6J mice once/day for three consecutive days. Lactate dehydrogenase (LDH) activity, inflammatory cells, and total protein concentration were analyzed in bronchoalveolar lavage fluid (BALF). Pattern recognition receptors levels (TLR3, MDA5 and RIG-I) were measured in lung homogenates using RT-qPCR and western blot. Gene expression of IFN-β, TNF-α, IL-1β and CXCL1 was assessed in lung homogenates by RT-qPCR. ELISA was used to analyze protein concentrations of CXCL1 and IL-1β in BALF and lung homogenates.RESULTS: BALB/c and C57Bl/6J mice showed infiltration of neutrophils to the lung, and an increase in total protein concentration and LDH activity in response to dsRNA administration. Only modest increases in these parameters were observed for C57Bl/6N mice. Similarly, dsRNA administration evoked an upregulation of MDA5 and RIG-I gene and protein expression in BALB/c and C57Bl/6J, but not C57Bl/6N, mice. Further, dsRNA provoked an increase in gene expression of TNF-α in BALB/c and C57Bl/6J mice, IL-1β only in C57Bl/6N mice and CXCL1 exclusively in BALB/c mice. BALF levels of CXCL1 and IL-1β were increased in BALB/c and C57Bl/6J mice in response to dsRNA, whereas the response of C57Bl/6N was blunt. Overall, inter-strain comparisons of the lung reactivity to dsRNA revealed that BALB/c, followed by C57Bl/6J, had the most pronounced respiratory inflammatory responses, while the responses of C57Bl/6N mice were attenuated.CONCLUSIONS: We report clear differences of the lung innate inflammatory response to dsRNA between BALB/c, C57Bl/6J and C57Bl/6N mice. Of particular note, the highlighted differences in the inflammatory response of C57Bl/6J and C57Bl/6N substrains underscore the value of strain selection in mouse models of respiratory viral infections.
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| 12. |
- Matthes, Frank, et al.
(författare)
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An Improved Method for Physical Separation of Cerebral Vasculature and Parenchyma Enables Detection of Blood-Brain-Barrier Dysfunction
- 2021
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Ingår i: NeuroSci. - : MDPI AG. - 2673-4087. ; 2:1, s. 59-74
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Tidskriftsartikel (refereegranskat)abstract
- The neurovascular niche is crucial for constant blood supply and blood-brain barrier (BBB) function and is altered in a number of different neurological conditions, making this an intensely active field of research. Brain vasculature is unique for its tight association of endothelial cells with astrocytic endfeet processes. Separation of the vascular compartment by centrifugation-based methods confirmed enrichment of astrocytic endfeet processes, making it possible to study the entire vascular niche with such methods. Several centrifugation-based separation protocols are found in the literature; however, with some constraints which limit their applicability and the scope of the studies. Here, we describe and validate a protocol for physically separating the neurovascular niche from the parenchyma, which is optimized for smaller tissue quantities. Using endothelial, neuronal, and astrocyte markers, we show that quantitative Western blot-based target detection can be performed of both the vessel-enriched and parenchymal fractions using as little as a single mouse brain hemisphere. Validation of our protocol in rodent stroke models by detecting changes in tight junction protein expression, serum albumin signals and astrocyte activation, i.e., increased glial fibrillary acidic protein expression, between the ipsilateral and the lesion-free contralateral hemisphere demonstrates this protocol as a new way of detecting BBB breakdown and astrogliosis, respectively.
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| 13. |
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| 14. |
- Meissner, Anja, et al.
(författare)
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Alterations to Cerebral Perfusion, Metabolite Profiles, and Neuronal Morphology in the Hippocampus and Cortex of Male and Female Mice during Chronic Exposure to a High-Salt Diet
- 2023
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Excess dietary salt reduces resting cerebral blood flow (CBF) and vascular reactivity, which can limit the fueling of neuronal metabolism. It is hitherto unknown whether metabolic derangements induced by high-salt-diet (HSD) exposure during adulthood are reversed by reducing salt intake. In this study, male and female mice were fed an HSD from 9 to 16 months of age, followed by a normal-salt diet (ND) thereafter until 23 months of age. Controls were continuously fed either ND or HSD. CBF and metabolite profiles were determined longitudinally by arterial spin labeling magnetic resonance imaging and magnetic resonance spectroscopy, respectively. HSD reduced cortical and hippocampal CBF, which recovered after dietary salt normalization, and affected hippocampal but not cortical metabolite profiles. Compared to ND, HSD increased hippocampal glutamine and phosphocreatine levels and decreased creatine and choline levels. Dietary reversal only allowed recovery of glutamine levels. Histology analyses revealed that HSD reduced the dendritic arborization and spine density of cortical and hippocampal neurons, which were not recovered after dietary salt normalization. We conclude that sustained HSD exposure throughout adulthood causes permanent structural and metabolic alterations to the mouse brain that are not fully normalized by lowering dietary salt during aging.
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| 15. |
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| 16. |
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| 17. |
- Munk, Anne Sofie, et al.
(författare)
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PDGF-B Is Required for Development of the Glymphatic System
- 2019
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Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; , s. 3-2969
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Tidskriftsartikel (refereegranskat)abstract
- The glymphatic system is a highly polarized cerebrospinal fluid (CSF) transport system that facilitates the clearance of neurotoxic molecules through a brain-wide network of perivascular pathways. Herein we have mapped the development of the glymphatic system in mice. Perivascular CSF transport first emerges in hippocampus in newborn mice, and a mature glymphatic system is established in the cortex at 2 weeks of age. Formation of astrocytic endfeet and polarized expression of aquaporin 4 (AQP4) consistently coincided with the appearance of perivascular CSF transport. Deficiency of platelet-derived growth factor B (PDGF-B) function in the PDGF retention motif knockout mouse line Pdgfb ret/ret suppressed the development of the glymphatic system, whose functions remained suppressed in adulthood compared with wild-type mice. These experiments map the natural development of the glymphatic system in mice and define a critical role of PDGF-B in the development of perivascular CSF transport.
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| 18. |
- Salas Perdomo, Angelica, et al.
(författare)
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Role of the S1P pathway and inhibition by fingolimod in preventing hemorrhagic transformation after stroke
- 2019
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- Hemorrhagic transformation (HT) is a complication of severe ischemic stroke after revascularization. Patients with low platelet counts do not receive reperfusion therapies due to high risk of HT. The immunomodulatory drug fingolimod attenuated HT after tissue plasminogen activator in a thromboembolic stroke model, but the underlying mechanism is unknown. Fingolimod acts on several sphingosine-1-phosphate (S1P) receptors, prevents lymphocyte trafficking to inflamed tissues, and affects brain and vascular cells. This study aimed to investigate changes in S1P-signaling in response to brain ischemia/reperfusion and the effects of the S1P receptor modulator fingolimod on HT. We studied brain expression of S1P signaling components, S1P concentration, and immune cell infiltration after ischemia/reperfusion in mice. We administered fingolimod after ischemia to wild-type mice, lymphocyte-deficient Rag2−/− mice, and mice with low platelet counts. Ischemia increased S1P-generating enzyme SphK1 mRNA, S1P concentration, and S1P receptor-1 (S1P1)+ T-cells in the brain. Fingolimod prevented lymphocyte infiltration, and attenuated the severity of HT in Rag2−/− mice but it was ineffective under thrombocytopenia. Fingolimod prevented β-catenin degradation but not Evans blue extravasation. Ischemia/reperfusion upregulates brain S1P signaling pathway, and fingolimod exerts local effects that attenuate HT. Although fingolimod seems to act on the brain tissue, it did not prevent blood-brain barrier leakage.
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| 19. |
- Skoug, Cecilia, et al.
(författare)
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Density of Sphingosine-1-Phosphate Receptors Is Altered in Cortical Nerve-Terminals of Insulin-Resistant Goto-Kakizaki Rats and Diet-Induced Obese Mice
- 2023
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Ingår i: Neurochemical Research. - 0364-3190.
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Tidskriftsartikel (refereegranskat)abstract
- Sphingosine-1-phosphate (S1P) is a phosphosphingolipid with pleiotropic biological functions. S1P acts as an intracellular second messenger, as well as extracellular ligand to five G-protein coupled receptors (S1PR1-5). In the brain, S1P regulates neuronal proliferation, apoptosis, synaptic activity and neuroglia activation. Moreover, S1P metabolism alterations have been reported in neurodegenerative disorders. We have previously reported that S1PRs are present in nerve terminals, exhibiting distinct sub-synaptic localization and neuromodulation actions. Since type 2 diabetes (T2D) causes synaptic dysfunction, we hypothesized that S1P signaling is modified in nerve terminals. In this study, we determined the density of S1PRs in cortical synaptosomes from insulin-resistant Goto-Kakizaki (GK) rats and Wistar controls, and from mice fed a high-fat diet (HFD) and low-fat-fed controls. Relative to their controls, GK rats showed similar cortical S1P concentration despite higher S1P levels in plasma, yet lower density of S1PR1, S1PR2 and S1PR4 in nerve-terminal-enriched membranes. HFD-fed mice exhibited increased plasma and cortical concentrations of S1P, and decreased density of S1PR1 and S1PR4. These findings point towards altered S1P signaling in synapses of insulin resistance and diet-induced obesity models, suggesting a role of S1P signaling in T2D-associated synaptic dysfunction.
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| 20. |
- Skoug, Cecilia, et al.
(författare)
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Sphingosine 1-Phoshpate Receptors are Located in Synapses and Control Spontaneous Activity of Mouse Neurons in Culture
- 2022
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Ingår i: Neurochemical Research. - : Springer Science and Business Media LLC. - 1573-6903 .- 0364-3190. ; 47:10, s. 3114-3125
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Tidskriftsartikel (refereegranskat)abstract
- Sphingosine-1-phosphate (S1P) is best known for its roles as vascular and immune regulator. Besides, it is also present in the central nervous system (CNS) where it can act as neuromodulator via five S1P receptors (S1PRs), and thus control neurotransmitter release. The distribution of S1PRs in the active zone and postsynaptic density of CNS synapses remains unknown. In the current study, we investigated the localization of S1PR1-5 in synapses of the mouse cortex. Cortical nerve terminals purified in a sucrose gradient were endowed with all five S1PRs. Further subcellular fractionation of cortical nerve terminals revealed S1PR2 and S1PR4 immunoreactivity in the active zone of presynaptic nerve terminals. Interestingly, only S1PR2 and S1PR3 immunoreactivity was found in the postsynaptic density. All receptors were present outside the active zone of nerve terminals. Neurons in the mouse cortex and primary neurons in culture showed immunoreactivity against all five S1PRs, and Ca 2+ imaging revealed that S1P inhibits spontaneous neuronal activity in a dose-dependent fashion. When testing selective agonists for each of the receptors, we found that only S1PR1, S1PR2 and S1PR4 control spontaneous neuronal activity. We conclude that S1PR2 and S1PR4 are located in the active zone of nerve terminals and inhibit neuronal activity. Future studies need to test whether these receptors modulate stimulation-induced neurotransmitter release.
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| 21. |
- Skoug, Cecilia, et al.
(författare)
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Subcellular localization of sphingosine 1-phosphate receptors in synapses of the mouse cortex
- 2019
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Ingår i: ; , s. 79-79
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Sphingosine 1-phosphate (S1P) has pleiotropic biological functions in the regulation of proliferation, survival, migration, inflammation or angiogenesis. S1P acts as intracellular second messenger, as well as extracellular receptor ligand via five G-protein coupled receptors (S1PR1-5). In the brain, S1P regulates neuronal proliferation or apoptosis, excitatory neurotransmission and neuroglia activation, and S1P metabolism alterations have been associated to neurodegenerative disorders. Interestingly, an agonist targeting S1PR1,3,4,5 (FTY720) shows neuroprotective properties through mechanisms that are not fully unveiled, but might include the control of neuroinflammation, vascular deterioration and synaptic dysfunction. The subcellular distribution of S1PRs in nerve terminals is hitherto unknown. The present study aimed at determining the synaptic localisation of S1PRs in the cortex of adult male mice. Synaptosomes were purified from mouse cortex homogenates using a sucrose density gradient centrifugation, and further fractioned into pre-, post- and extrasynaptic zones using a series of pH shifts that allow successive solubilisation of synaptic components (Phillips et al., Neuron 32:63, 2001). Western blot analysis of the obtained fractions, as well as total protein extracts from cortex revealed that S1PR1 is present in similar amounts in total extracts, synaptosomes and the extrasynaptic fraction, but absent from the pre- and postsynaptic fractions. S1PR2 was ubiquitously distributed, showing 3-fold higher levels in the presynaptic zone than the post- (P<0.05) and extrasynaptic (P<0.05) fractions. Similarly, S1PR4 was also distributed across all synaptic fractions but 4-fold more enriched presynaptically. S1PR3 and S1PR5 were not efficiently detected by immunoblotting in synaptosomes and synaptic fractions. Altogether, these results point towards S1PR2 and S1PR4 being particularly well poised to directly modulate synaptic transmission and plasticity upon S1P activation.
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| 22. |
- Uhl, Franziska E, et al.
(författare)
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Cystic fibrosis transmembrane regulator correction attenuates heart failure-induced lung inflammation
- 2022
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Heart failure (HF) affects 64 million people worldwide. Despite advancements in prevention and therapy, quality of life remains poor for many HF patients due to associated target organ damage. Pulmonary manifestations of HF are well-established. However, difficulties in the treatment of HF patients with chronic lung phenotypes remain as the underlying patho-mechanistic links are still incompletely understood. Here, we aim to investigate the cystic fibrosis transmembrane regulator (CFTR) involvement in lung inflammation during HF, a concept that may provide new mechanism-based therapies for HF patients with pulmonary complications. In a mouse model of HF, pharmacological CFTR corrector therapy (Lumacaftor (Lum)) was applied systemically or lung-specifically for 2 weeks, and the lungs were analyzed using histology, flow cytometry, western blotting, and qPCR. Experimental HF associated with an apparent lung phenotype characterized by vascular inflammation and remodeling, pronounced tissue inflammation as evidenced by infiltration of pro-inflammatory monocytes, and a reduction of pulmonary CFTR+ cells. Moreover, the elevation of a classically-activated phenotype of non-alveolar macrophages coincided with a cell-specific reduction of CFTR expression. Pharmacological correction of CFTR with Lum mitigated the HF-induced downregulation of pulmonary CFTR expression and increased the proportion of CFTR+ cells in the lung. Lum treatment diminished the HF-associated elevation of classically-activated non-alveolar macrophages, while promoting an alternatively-activated macrophage phenotype within the lungs. Collectively, our data suggest that downregulation of CFTR in the HF lung extends to non-alveolar macrophages with consequences for tissue inflammation and vascular structure. Pharmacological CFTR correction possesses the capacity to alleviate HF-associated lung inflammation.
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| 23. |
- Uhl, Franziska, et al.
(författare)
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Therapeutic CFTR Correction Normalizes Systemic and Lung-Specific S1P Level Alterations Associated with Heart Failure
- 2022
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 23:2
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Tidskriftsartikel (refereegranskat)abstract
- Heart failure (HF) is among the main causes of death worldwide. Alterations of sphingosine-1-phosphate (S1P) signaling have been linked to HF as well as to target organ damage that is often associated with HF. S1P's availability is controlled by the cystic fibrosis transmembrane regulator (CFTR), which acts as a critical bottleneck for intracellular S1P degradation. HF induces CFTR downregulation in cells, tissues and organs, including the lung. Whether CFTR alterations during HF also affect systemic and tissue-specific S1P concentrations has not been investigated. Here, we set out to study the relationship between S1P and CFTR expression in the HF lung. Mice with HF, induced by myocardial infarction, were treated with the CFTR corrector compound C18 starting ten weeks post-myocardial infarction for two consecutive weeks. CFTR expression, S1P concentrations, and immune cell frequencies were determined in vehicle- and C18-treated HF mice and sham controls using Western blotting, flow cytometry, mass spectrometry, and qPCR. HF led to decreased pulmonary CFTR expression, which was accompanied by elevated S1P concentrations and a pro-inflammatory state in the lungs. Systemically, HF associated with higher S1P plasma levels compared to sham-operated controls and presented with higher S1P receptor 1-positive immune cells in the spleen. CFTR correction with C18 attenuated the HF-associated alterations in pulmonary CFTR expression and, hence, led to lower pulmonary S1P levels, which was accompanied by reduced lung inflammation. Collectively, these data suggest an important role for the CFTR-S1P axis in HF-mediated systemic and pulmonary inflammation.
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| 24. |
- Vanherle, Lotte, et al.
(författare)
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Improving cerebrovascular function to increase neuronal recovery in neurodegeneration associated to cardiovascular disease
- 2020
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Ingår i: Frontiers in cell and developmental biology. - : Frontiers Media SA. - 2296-634X. ; 8
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Forskningsöversikt (refereegranskat)abstract
- Mounting evidence indicates that the presence of cardiovascular disease (CVD) and risk factors elevates the incidence of cognitive impairment (CI) and dementia. CVD and associated decline in cardiovascular function can impair cerebral blood flow (CBF) regulation, leading to the disruption of oxygen and nutrient supply in the brain where limited intracellular energy storage capacity critically depends on CBF to sustain proper neuronal functioning. During hypertension and acute as well as chronic CVD, cerebral hypoperfusion and impaired cerebrovascular function are often associated with neurodegeneration and can lead to CI and dementia. Currently, all forms of neurodegeneration associated to CVD lack effective treatments, which highlights the need to better understand specific mechanisms linking cerebrovascular dysfunction and CBF deficits to neurodegeneration. In this review, we discuss vascular targets that have already shown attenuation of neurodegeneration or CI associated to hypertension, heart failure (HF) and stroke by improving cerebrovascular function or CBF deficits.
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| 25. |
- Vanherle, Lotte, et al.
(författare)
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Ivacaftor therapy post myocardial infarction augments systemic inflammation and evokes contrasting effects with respect to tissue inflammation in brain and lung
- 2023
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Ingår i: Biomedicine and Pharmacotherapy. - 1950-6007. ; 162
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Tidskriftsartikel (refereegranskat)abstract
- Acquired cystic fibrosis transmembrane regulator (CFTR) dysfunctions have been associated with several conditions, including myocardial infarction (MI). Here, CFTR is downregulated in brain, heart, and lung tissue and associates with inflammation and degenerative processes. Therapeutically increasing CFTR expression attenuates these effects. Whether potentiating CFTR function yields similar beneficial effects post-MI is unknown. The CFTR potentiator ivacaftor is currently in clinical trials for treatment of acquired CFTR dysfunction associated with chronic obstructive pulmonary disease and chronic bronchitis. Thus, we tested ivacaftor as therapeutic strategy for MI-associated target tissue inflammation that is characterized by CFTR alterations. MI was induced in male C57Bl/6 mice by ligation of the left anterior descending coronary artery. Mice were treated with ivacaftor starting ten weeks post-MI for two consecutive weeks. Systemic ivacaftor treatment ameliorates hippocampal neuron dendritic atrophy and spine loss and attenuates hippocampus-dependent memory deficits occurring post-MI. Similarly, ivacaftor therapy mitigates MI-associated neuroinflammation (i.e., reduces higher proportions of activated microglia). Systemically, ivacaftor leads to higher frequencies of circulating Ly6C + and Ly6C hi cells compared to vehicle-treated MI mice. Likewise, an ivacaftor-mediated augmentation of MI-associated pro-inflammatory macrophage phenotype characterized by higher CD80-positivity is observed in the MI lung. In vitro, ivacaftor does not alter LPS-induced CD80 and tumor necrosis factor alpha mRNA increases in BV2 microglial cells, while augmenting mRNA levels of these markers in mouse macrophages and differentiated human THP-1-derived macrophages. Our results suggest that ivacaftor promotes contrasting effects depending on target tissue post-MI, which may be largely dependent on its effects on different myeloid cell types.
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- Vanherle, Lotte, et al.
(författare)
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Restoring myocardial infarction-induced long-term memory impairment by targeting the cystic fibrosis transmembrane regulator
- 2022
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Ingår i: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 86
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cognitive impairment is a serious comorbidity in heart failure patients, but effective therapies are lacking. We investigated the mechanisms that alter hippocampal neurons following myocardial infarction (MI).METHODS: MI was induced in male C57Bl/6 mice by left anterior descending coronary artery ligation. We utilised standard procedures to measure cystic fibrosis transmembrane regulator (CFTR) protein levels, inflammatory mediator expression, neuronal structure, and hippocampal memory. Using in vitro and in vivo approaches, we assessed the role of neuroinflammation in hippocampal neuron degradation and the therapeutic potential of CFTR correction as an intervention.FINDINGS: Hippocampal dendrite length and spine density are reduced after MI, effects that associate with decreased neuronal CFTR expression and concomitant microglia activation and inflammatory cytokine expression. Conditioned medium from lipopolysaccharide-stimulated microglia (LCM) reduces neuronal cell CFTR protein expression and the mRNA expression of the synaptic regulator post-synaptic density protein 95 (PSD-95) in vitro. Blocking CFTR activity also down-regulates PSD-95 in neurons, indicating a relationship between CFTR expression and neuronal health. Pharmacologically correcting CFTR expression in vitro rescues the LCM-mediated down-regulation of PSD-95. In vivo, pharmacologically increasing hippocampal neuron CFTR expression improves MI-associated alterations in neuronal arborisation, spine density, and memory function, with a wide therapeutic time window.INTERPRETATION: Our results indicate that CFTR therapeutics improve inflammation-induced alterations in hippocampal neuronal structure and attenuate memory dysfunction following MI.
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