| 1. |
- de la Rosa, Andres, et al.
(författare)
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Introducing or removing heparan sulfate binding sites does not alter brain uptake of the blood-brain barrier shuttle scFv8D3
- 2022
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- The blood-brain barrier (BBB) greatly limits the delivery of protein-based drugs into the brain and is a major obstacle for the treatment of brain disorders. Targeting the transferrin receptor (TfR) is a strategy for transporting protein-based drugs into the brain, which can be utilized by using TfR-binding BBB transporters, such as the TfR-binding antibody 8D3. In this current study, we investigated if binding to heparan sulfate (HS) contributes to the brain uptake of a single chain fragment variable of 8D3 (scFv8D3). We designed and produced a scFv8D3 mutant, engineered with additional HS binding sites, HS(+)scFv8D3, to assess whether increased HS binding would improve brain uptake. Additionally, a mutant with a reduced number of HS binding sites, HS(-)scFv8D3, was also engineered to see if reducing the HS binding sites could also affect brain uptake. Heparin column chromatography showed that only the HS(+)scFv8D3 mutant bound HS in the experimental conditions. Ex vivo results showed that the brain uptake was unaffected by the introduction or removal of HS binding sites, which indicates that scFv8D3 is not dependent on the HS binding sites for brain uptake. Conversely, introducing HS binding sites to scFv8D3 decreased its renal excretion while removing them had the opposite effect.
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| 2. |
- Fogleman, Nicholas D., et al.
(författare)
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Regional variation in quality of life in patients with a Fontan circulation: A multinational perspective
- 2017
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Ingår i: American Heart Journal. - : Elsevier BV. - 0002-8703 .- 1097-6744. ; 193, s. 55-62
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Tidskriftsartikel (refereegranskat)abstract
- © 2017 Elsevier Inc. Background Impaired quality of life (QOL) is associated with congenital heart disease (CHD) and country of residence; however, few studies have compared QOL in patients with differing complexities of CHD across regional populations. The current study examined regional variation in QOL outcomes in a large multinational sample of patients with a Fontan relative to patients with atrial septal defects (ASDs) and ventricular septal defects (VSDs). Methods From the Assessment of Patterns of Patient-Reported Outcomes in Adults with Congenital Heart disease—International Study (APPROACH-IS), 405 patients (163 Fontan and 242 ASD/VSD) across Asia, Europe, and North America provided consent for access to their medical records and completed a survey evaluating QOL (0 to 100 linear analog scale). Primary CHD diagnosis, disease complexity, surgical history, and documented history of mood and anxiety disorders were recorded. Differences in QOL, medical complications, and mood and anxiety disorders between Fontan and ASD/VSD patients, and across geographic regions, were examined using analysis of covariance. Hierarchical regression analyses were conducted to identify variables associated with the QOL ratings. Results Patients with a Fontan reported significantly lower QOL, and greater medical complications and mood and anxiety disorders relative to patients with ASD/VSD. Inpatient cardiac admissions, mood disorders, and anxiety disorders were associated with lower QOL among patients with a Fontan, and mood disorders were associated with lower QOL among patients with ASD/VSD. Regional differences for QOL were not observed in patients with a Fontan; however, significant differences were identified in patients with ASD/VSD. Conclusions Regional variation of QOL is commonplace in adults with CHD; however, it appears affected by greater disease burden. Among patients with a Fontan, regional variation of QOL is lost. Specific attempts to screen for QOL and mood and anxiety disorders among CHD patients may improve the care of patients with the greatest disease burden.
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| 3. |
- Garcia-Gonzalez, Claudia, et al.
(författare)
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Cardiac regeneration in non-mammalian vertebrates
- 2014
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827 .- 1090-2422. ; 321:1, s. 58-63
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Forskningsöversikt (refereegranskat)abstract
- The heart is a robust organ, capable of pumping nutrients and transferring oxygen throughout the body via a network of capillaries, veins and arteries, for the entirety of a human's life. However, the fragility of mammalian hearts is also evident when it becomes damaged and parts of the organ fail to function. This is due to the fact that rather than replenishing the damaged areas with functional cellular mass, fibrotic scar tissue is the preferred replacement, resulting in an organ with functional deficiencies. Due to the mammalian hearts incapability to regenerate following damage and the ever-increasing number of people worldwide suffering from heart disease, tireless efforts are being made to discover ways of inducing a regenerative response in this most important organ. One such avenue of investigation involves studying our distantly related non-mammalian vertebrate cousins, which over the last decade has proved to us that cardiac regeneration is possible. This review will highlight these organisms and provide insights into some of the seminal discoveries made in the heart regeneration field using these amazing chordates.
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| 4. |
- Holbein, Christina E., et al.
(författare)
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A multinational observational investigation of illness perceptions and quality of life among patients with a Fontan circulation
- 2018
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Ingår i: Congenital Heart Disease. - : Computers, Materials and Continua (Tech Science Press). - 1747-079X .- 1747-0803. ; 13:3, s. 392-400
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Tidskriftsartikel (refereegranskat)abstract
- Objective First, to compare QOL and illness perceptions between patients with a Fontan circulation and patients with anatomically simple defects (ie, atrial septal defects [ASD] or ventricular septal defects [VSD]). Second, to explore illness perceptions as a mediator of the association between congenital heart disease (CHD) diagnosis and QOL. Design Cross-sectional observational study. Setting Twenty-four cardiology centers from 15 countries across five continents. Patients Four hundred thirty-five adult patients with congenital heart disease (177 Fontan and 258 ASD/VSD) ages 18-83 years. Outcome Measures QOL and illness perceptions were assessed by the Satisfaction With Life Scale and the Brief Illness Perceptions Questionnaire, respectively. Results Patients with a Fontan circulation reported lower QOL (Wald Z = −3.59, p = <.001) and more negative perceptions of their CHD (Wald Z = −7.66, p < .001) compared with patients with ASD/VSD. After controlling for demographics, anxiety, depressive symptoms, and New York Heart Association functional class, path analyses revealed a significant mediation model, αβ = 0.15, p = .002, 95% CI = 0.06-0.25, such that CHD diagnosis was indirectly related to QOL through illness perceptions. Conclusions The Fontan sample’s more negative perceptions of CHD were likely a reflection of life with a more complex defect. Illness perceptions appear to account for unique differences in QOL between groups of varying CHD complexity. Psychosocial screening and interventions may be important treatment components for patients with CHD, particularly those with Fontan circulations.
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| 5. |
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| 6. |
- Milham, Michael P., et al.
(författare)
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An Open Resource for Non-human Primate Imaging
- 2018
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Ingår i: Neuron. - : Elsevier BV. - 0896-6273 .- 1097-4199. ; 100:1, s. 61-74
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Tidskriftsartikel (refereegranskat)abstract
- Non-human primate neuroimaging is a rapidly growing area of research that promises to transform and scale translational and cross-species comparative neuroscience. Unfortunately, the technological and methodological advances of the past two decades have outpaced the accrual of data, which is particularly challenging given the relatively few centers that have the necessary facilities and capabilities. The PRIMatE Data Exchange (PRIME-DE) addresses this challenge by aggregating independently acquired non-human primate magnetic resonance imaging (MRI) datasets and openly sharing them via the International Neuroimaging Data-sharing Initiative (INDI). Here, we present the rationale, design, and procedures for the PRIME-DE consortium, as well as the initial release, consisting of 25 independent data collections aggregated across 22 sites (total = 217 non-human primates). We also outline the unique pitfalls and challenges that should be considered in the analysis of non-human primate MRI datasets, including providing automated quality assessment of the contributed datasets.
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| 7. |
- Morrison, Jamie I., et al.
(författare)
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A single-chain fragment constant design enables easy production of a monovalent blood-brain barrier transporter and provides an improved brain uptake at elevated doses
- 2023
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Ingår i: Journal of Neurochemistry. - : John Wiley & Sons. - 0022-3042 .- 1471-4159. ; 165:3, s. 413-425
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Tidskriftsartikel (refereegranskat)abstract
- The interest for developing antibody-driven therapeutic interventions has exponentially grown over the last few decades. Even though there have been promising leaps in the development of efficacious antibody therapies, problems revolving around production and site-directed delivery of these large macromolecules persist. This is especially pertinent when it comes to designing and producing antibodies to penetrate the blood-brain barrier (BBB) to tackle neurodegenerative diseases. One of the most effective approaches to alleviating this problem is to employ a "Trojan Horse " approach, using receptor-mediated transcytosis, such as those governed by the transferrin receptor (TfR)-mediated pathways, to deliver large protein payloads into the brain. Even though this method is effective, ideal limiting factors, related to how the antibody binds to the TfR, need to be elucidated to improve BBB penetrance. With this said, we have designed and produced a single-chain Fc antibody, conjugated to an scFv8D3 TfR binding motif, creating a single-chain monovalent BBB transporter (scFc-scFv8D3). This recombinant protein is easy to produce and purify, demonstrates monovalent binding to the TfR and is structurally stable at physiologically relevant temperatures. Using an in vitro BBB model system, we show a positive correlation between the concentration of administered antibody and transcytosis efficacy, with scFc-scFv8D3 demonstrating significantly higher transcytosis levels compared with scFv8D3-conjugated bivalent antibodies at elevated administered concentrations. Furthermore, in vivo studies recapitulate the in vitro results, with the scFc-scFv8D3 demonstrating an elevated brain uptake at higher therapeutic doses in wild-type mice, comparable with that of the scFv8D3-conjugated bivalent antibody control. In addition, the half-life of the single-chain monovalent BBB transporter is comparable with that of standard IgG antibodies, indicating that the scFc format does not exacerbate physiological degradation. Our results lead us to the conclusion that valency and affinity are important variables to consider when discerning optimal transport across the BBB using TfR-mediated transcytosis pathways. In addition, we believe the single-chain Fc antibody we have described, which can easily be manipulated to accommodate a bispecific target tactic, provides a simple and efficacious approach for delivering therapeutic payloads to the brain milieu.
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| 8. |
- Morrison, Jamie Ian
(författare)
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Editing our way to regeneration
- 2014
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Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 356:3, s. 533-537
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Forskningsöversikt (refereegranskat)abstract
- Transcription is the primary regulatory step to gene expression. However, there are numerous post-transcriptional mechanisms that are also crucial for developing the transcritptome, and the subsequent proteome, signature of any physiological setting. Organ and tissue regeneration is one such physiological setting that requires the rapid development of an environment that can supply all of the necessary molecular and cellular signalling needs necessary to attenuate infection, remove dead or necrotic cells, provide structural stability and finally replenish the compromised area with functional cells. The post-transcriptional regulatory mechanisms that have the ability to heavily influence the molecular and cellular pathways associated with regeneration are slowly being characterized. This mini-review will further clarify the possible regulation of regeneration through adenosine-to-inosine (A-I) RNA editing; a post-transcriptional mechanism that can affect the molecular and cellular pathways associated with functional restoration of damaged tissues and organs through discrete nucleotide changes in RNA transcripts. It is hoped that the intriguing links made between A-I RNA editing and regeneration in this mini-review will encourage further comparative studies into this infant field of research.
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| 9. |
- Morrison, Jamie I, et al.
(författare)
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Plasticity and recovery of skeletal muscle satellite cells during limb regeneration
- 2010
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Ingår i: The FASEB Journal. - : FASEB. - 0892-6638 .- 1530-6860. ; 24:3, s. 750-756
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Tidskriftsartikel (refereegranskat)abstract
- Salamander limb regeneration depends on local progenitors whose progeny are recruited to the new limb. We previously identified a Pax7+ cell population in skeletal muscle whose progeny have the potential to contribute to the regenerating limb. However, the plasticity of individual Pax7+ cells, as well as their recovery within the new limb, was unclear. Here, we show that Pax7+ cells remain present after multiple rounds of limb amputation/regeneration. Pax7+ cells are found exclusively within skeletal muscle in the regenerating limb and proliferate where the myofibers are growing. Pax7 is rapidly down-regulated in the blastema, and analyses of clonal derivatives show that Pax7+ cell progeny are not restricted to skeletal muscle during limb regeneration. Our data suggest that the newt regeneration blastema is not entirely a composite of lineage-restricted progenitors. The results demonstrate that except for a transient and subsequently blunted increase, skeletal muscle satellite cells constitute a stable pool of reserve cells for multiple limb regeneration events.
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| 10. |
- Morrison, Jamie, et al.
(författare)
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Standardized Preclinical In Vitro Blood-Brain Barrier Mouse Assay Validates Endocytosis-Dependent Antibody Transcytosis Using Transferrin-Receptor-Mediated Pathways
- 2023
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Ingår i: Molecular Pharmaceutics. - : American Chemical Society (ACS). - 1543-8384 .- 1543-8392. ; 20:3, s. 1564-1576
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Tidskriftsartikel (refereegranskat)abstract
- The presence of the blood-brain barrier (BBB) creates a nigh-on impenetrable obstacle for large macromolecular therapeutics that need to be delivered to the brain milieu to treat neurological disorders. To overcome this, one of the strategies used is to bypass the barrier with what is referred to as a "Trojan Horse" strategy, where therapeutics are designed to use endogenous receptor-mediated pathways to piggyback their way through the BBB. Even though in vivo methodologies are commonly used to test the efficacy of BBB-penetrating biologics, comparable in vitro BBB models are in high demand, as they benefit from being an isolated cellular system devoid of physiological factors that can on occasion mask the processes behind BBB transport via transcytosis. We have developed an in vitro BBB model (In-Cell BBB-Trans assay) based on the murine cEND cells that help delineate the ability of modified large bivalent IgG antibodies conjugated to the transferrin receptor binder scFv8D3 to cross an endothelial monolayer grown on porous cell culture inserts (PCIs). Following the administration of bivalent antibodies into the endothelial monolayer, a highly sensitive enzyme-linked immunosorbent assay (ELISA) is used to determine the concentration in the apical (blood) and basolateral (brain) chambers of the PCI system, allowing for the evaluation of apical recycling and basolateral transcytosis, respectively. Our results show that antibodies conjugated to scFv8D3 transcytose at considerably higher levels compared to unconjugated antibodies in the In-Cell BBB-Trans assay. Interestingly, we are able to show that these results mimic in vivo brain uptake studies using identical antibodies. In addition, we are able to transversely section PCI cultured cells, allowing for the identification of receptors and proteins that are likely involved in the transcytosis of the antibodies. Furthermore, studies using the In-Cell BBB-Trans assay revealed that transcytosis of the transferrin-receptor-targeting antibodies is dependent on endocytosis. In conclusion, we have designed a simple, reproducible In-Cell BBB-Trans assay based on murine cells that can be used to rapidly determine the BBB-penetrating capabilities of transferrin-receptor-targeting antibodies. We believe that the In-Cell BBB-Trans assay can be used as a powerful, preclinical screening platform for therapeutic neurological pathologies.
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