| 1. |
- Börgeson, Emma, et al.
(author)
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AICAR ameliorates high-fat diet-associated pathophysiology in mouse and ex vivo models, independent of adiponectin.
- 2017
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In: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 60:4, s. 729-739
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Journal article (peer-reviewed)abstract
- In this study, we aimed to evaluate the therapeutic potential of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), an activator of AMP-activated protein kinase, for ameliorating high-fat diet (HFD)-induced pathophysiology in mice. We also aimed to determine whether the beneficial effects of AICAR were dependent on adiponectin. Furthermore, human adipose tissue was used to examine the effect of AICAR ex vivo.Six-week-old male C57BL/6J wild-type and Adipoq (-/-) mice were fed a standard-fat diet (10% fat) or an HFD (60% fat) for 12weeks and given vehicle or AICAR (500μg/g) three times/week from weeks 4-12. Diet-induced pathophysiology was examined in mice after 11 weeks by IPGTT and after 12 weeks by flow cytometry and western blotting. Human adipose tissue biopsies from obese (BMI 35-50kg/m(2)) individuals were incubated with vehicle or AICAR (1mmol/l) for 6h at 37°C, after which inflammation was characterised by ELISA (TNF-α) and flow cytometry.AICAR attenuated adipose inflammation in mice fed an HFD, promoting an M1-to-M2 macrophage phenotype switch, while reducing infiltration of CD8(+) T cells. AICAR treatment of mice fed an HFD partially restored glucose tolerance and attenuated hepatic steatosis and kidney disease, as evidenced by reduced albuminuria (p<0.05), urinary H2O2 (p<0.05) and renal superoxide levels (p<0.01) in both wild-type and Adipoq (-/-) mice. AICAR-mediated protection occurred independently of adiponectin, as similar protection was observed in wild-type and Adipoq (-/-) mice. In addition, AICAR promoted an M1-to-M2 macrophage phenotype switch and reduced TNF-α production in tissue explants from obese human patients.AICAR may promote metabolic health and protect against obesity-induced systemic diseases in an adiponectin-independent manner. Furthermore, AICAR reduced inflammation in human adipose tissue explants, suggesting by proof-of-principle that the drug may reduce obesity-induced complications in humans.ClinicalTrials.gov NCT02322073.
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| 2. |
- Börgeson, Emma, et al.
(author)
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Challenges in PhD education due to COVID-19-disrupted supervision or business as usual: a cross-sectional survey of Swedish biomedical sciences graduate students
- 2021
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In: Bmc Medical Education. - : Springer Science and Business Media LLC. - 1472-6920. ; 21:1
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Journal article (peer-reviewed)abstract
- Background It remains unclear to what extent the SARS-CoV-2/COVID-19 pandemic disrupted the normal progression of biomedical and medical science graduate programs and if there was a lasting impact on the quality and quantity of supervision of PhD-students. To date, multiple editorials and commentaries indicate the severity of the disruption without providing sufficient evidence with quantifiable data. Methods An online survey was submitted to the administrative offices of biomedical and medical PhD-programs at eight major universities in Sweden to gauge the impact of the pandemic on the students. It consisted of multiple-choice and open-ended questions where students could provide examples of positive and/or negative supervision strategies. Open answered questions were coded as either examples of positive or negative support. Results PhD students were divided into two groups: those with improved or unchanged supervision during the pandemic (group 1, n = 185), versus those whose supervision worsened (group 2, n = 69). Group 1 received more help from supervisors and more frequent supervision via both online and alternative platforms (email/messages and telephone). There was no significant difference in educational-stage, gender or caretaking responsibilities between the groups. Conclusions It is important for the scientific community to learn how to provide the best possible supervision for PhD students during the pandemic. Our data suggests that more frequent supervision, and using a diverse array of meeting platforms is helpful. In addition, it is important for the students to feel that they have their supervisor's emotional support. Several students also expressed that they would benefit from an extension of their PhD programs due to delays caused by the pandemic.
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| 3. |
- Börgeson, Emma, et al.
(author)
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Lipoxin A(4) inhibits porphyromonas gingivalis-induced aggregation and reactive oxygen species production by modulating neutrophil-platelet interaction and CD11b expression
- 2011
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In: Infection and Immunity. - : American Society for Microbiology. - 0019-9567 .- 1098-5522. ; 79:4, s. 1489-1497
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Journal article (peer-reviewed)abstract
- Porphyromonas gingivalis is an etiological agent that is strongly associated with periodontal disease, and it correlates with numerous inflammatory disorders, such as cardiovascular disease. Circulating bacteria may contribute to atherogenesis by promoting CD11b/CD18-mediated interactions between neutrophils and platelets, causing reactive oxygen species (ROS) production and aggregation. Lipoxin A(4) (LXA(4)) is an endogenous anti-inflammatory and proresolving mediator that is protective of inflammatory disorders. The aim of this study was to investigate the effect of LXA(4) on the P. gingivalis-induced activation of neutrophils and platelets and the possible involvement of Rho GTPases and CD11b/CD18 integrins. Platelet/leukocyte aggregation and ROS production was examined by lumiaggregometry and fluorescence microscopy. Integrin activity was studied by flow cytometry, detecting the surface expression of CD11b/CD18 as well as the exposure of the high-affinity integrin epitope, whereas the activation of Rac2/Cdc42 was examined using a glutathione S-transferase pulldown assay. The study shows that P. gingivalis activates Rac2 and Cdc42 and upregulates CD11b/CD18 and its high-affinity epitope on neutrophils, and that these effects are diminished by LXA(4). Furthermore, we found that LXA(4) significantly inhibits P. gingivalis-induced aggregation and ROS generation in whole blood. However, in platelet-depleted blood and in isolated neutrophils and platelets, LXA(4) was unable to inhibit either aggregation or ROS production, respectively. In conclusion, this study suggests that LXA(4) antagonizes P. gingivalis-induced cell activation in a manner that is dependent on leukocyte-platelet interaction, likely via the inhibition of Rho GTPase signaling and the downregulation of CD11b/CD18. These findings may contribute to new strategies in the prevention and treatment of periodontitis-induced inflammatory disorders, such as atherosclerosis.
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| 4. |
- Börgeson, Emma, et al.
(author)
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Of mice and men: Pinpointing species differences in adipose tissue biology
- 2022
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In: Frontiers in Cell and Developmental Biology. - : Frontiers Media SA. - 2296-634X. ; 10
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Journal article (peer-reviewed)abstract
- The prevalence of obesity and metabolic diseases continues to rise, which has led to an increased interest in studying adipose tissue to elucidate underlying disease mechanisms. The use of genetic mouse models has been critical for understanding the role of specific genes for adipose tissue function and the tissue's impact on other organs. However, mouse adipose tissue displays key differences to human fat, which has led, in some cases, to the emergence of some confounding concepts in the adipose field. Such differences include the depot-specific characteristics of visceral and subcutaneous fat, and divergences in thermogenic fat phenotype between the species. Adipose tissue characteristics may therefore not always be directly compared between species, which is important to consider when setting up new studies or interpreting results. This mini review outlines our current knowledge about the cell biological differences between human and mouse adipocytes and fat depots, highlighting some examples where inadequate knowledge of species-specific differences can lead to confounding results, and presenting plausible anatomic explanations that may underlie the differences. The article thus provides critical insights and guidance for researchers working primarily with only human or mouse fat tissue, and may contribute to new ideas or concepts in the important and evolving field of adipose biology.
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| 5. |
- Fleming, J. R., et al.
(author)
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Exploring Obscurin and SPEG Kinase Biology
- 2021
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In: Journal of Clinical Medicine. - : MDPI AG. - 2077-0383. ; 10:5
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Journal article (peer-reviewed)abstract
- Three members of the obscurin protein family that contain tandem kinase domains with important signaling functions for cardiac and striated muscles are the giant protein obscurin, its obscurin-associated kinase splice isoform, and the striated muscle enriched protein kinase (SPEG). While there is increasing evidence for the specific roles that each individual kinase domain plays in cross-striated muscles, their biology and regulation remains enigmatic. Our present study focuses on kinase domain 1 and the adjacent low sequence complexity inter-kinase domain linker in obscurin and SPEG. Using Phos-tag gels, we show that the linker in obscurin contains several phosphorylation sites, while the same region in SPEG remained unphosphorylated. Our homology modeling, mutational analysis and molecular docking demonstrate that kinase 1 in obscurin harbors all key amino acids important for its catalytic function and that actions of this domain result in autophosphorylation of the protein. Our bioinformatics analyses also assign a list of putative substrates for kinase domain 1 in obscurin and SPEG, based on the known and our newly proposed phosphorylation sites in muscle proteins, including obscurin itself.
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| 6. |
- Hernandez-Carretero, A., et al.
(author)
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Obesity-induced changes in lipid mediators persist after weight loss
- 2018
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In: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 42:4, s. 728-736
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Journal article (peer-reviewed)abstract
- Background:Obesity induces significant changes in lipid mediators, however, the extent to which these changes persist after weight loss has not been investigated.Subjects/Methods:We fed C57BL6 mice a high-fat diet to generate obesity and then switched the diet to a lower-fat diet to induce weight loss. We performed a comprehensive metabolic profiling of lipid mediators including oxylipins, endocannabinoids, sphingosines and ceramides in key metabolic tissues (including adipose, liver, muscle and hypothalamus) and plasma.Results:We found that changes induced by obesity were largely reversible in most metabolic tissues but the adipose tissue retained a persistent obese metabolic signature. Prostaglandin signaling was perturbed in the obese state and lasting increases in PGD 2, and downstream metabolites 15-deoxy PGJ 2 and delta-12-PGJ 2 were observed after weight loss. Furthermore expression of the enzyme responsible for PGD 2 synthesis (hematopoietic prostaglandin D synthase, HPGDS) was increased in obese adipose tissues and remained high after weight loss. We found that inhibition of HPGDS over the course of 5 days resulted in decreased food intake in mice. Increased HPGDS expression was also observed in human adipose tissues obtained from obese compared with lean individuals. We then measured circulating levels of PGD 2 in obese patients before and after weight loss and found that while elevated relative to lean subjects, levels of this metabolite did not decrease after significant weight loss.Conclusions:These results suggest that lasting changes in lipid mediators induced by obesity, still present after weight loss, may play a role in the biological drive to regain weight. © 2018 Macmillan Publishers Limited.
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| 7. |
- Kraft, Jamie D., et al.
(author)
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Lipoxins modulate neutrophil oxidative burst, integrin expression and lymphatic transmigration differentially in human health and atherosclerosis
- 2022
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In: FASEB Journal. - Hoboken, NJ, United States : John Wiley & Sons. - 0892-6638 .- 1530-6860. ; 36:3
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Journal article (peer-reviewed)abstract
- Dysregulated chronic inflammation plays a crucial role in the pathophysiology of atherosclerosis and may be a result of impaired resolution. Thus, restoring levels of specialized pro-resolving mediators (SPMs) to promote the resolution of inflammation has been proposed as a therapeutic strategy for patients with atherosclerosis, in addition to standard clinical care. Herein, we evaluated the effects of the SPM lipids, lipoxin A4 (LXA4) and lipoxin B4 (LXB4), on neutrophils isolated from patients with atherosclerosis compared with healthy controls. Patients displayed altered endogenous SPM production, and we demonstrated that lipoxin treatment in whole blood from atherosclerosis patients attenuates neutrophil oxidative burst, a key contributor to atherosclerotic development. We found the opposite effect in neutrophils from healthy controls, indicating a potential mechanism whereby lipoxins aid the endogenous neutrophil function in health but reduce its excessive activation in disease. We also demonstrated that lipoxins attenuated upregulation of the high-affinity conformation of the CD11b/CD18 integrin, which plays a central role in clot activation and atherosclerosis. Finally, LXB4 enhanced lymphatic transmigration of human neutrophils isolated from patients with atherosclerosis. This finding is noteworthy, as impaired lymphatic function is now recognized as an important contributor to atherosclerosis. Although both lipoxins modulated neutrophil function, LXB4 displayed more potent effects than LXA4 in humans. This study highlights the therapeutic potential of lipoxins in atherosclerotic disease and demonstrates that the effect of these SPMs may be specifically tailored to the need of the individual. © 2022 The Authors. The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.
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| 8. |
- Kraft, Jamie D., et al.
(author)
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Specialized Pro-Resolving Mediators and the Lymphatic System
- 2021
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In: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067 .- 1661-6596. ; 22:5
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Journal article (peer-reviewed)abstract
- Diminished lymphatic function and abnormal morphology are common in chronic inflammatory diseases. Recent studies are investigating whether it is possible to target chronic inflammation by promoting resolution of inflammation, in order to enhance lymphatic function and attenuate disease. Resolution of inflammation is an active process regulated by bioactive lipids known as specialized pro-resolving mediators (SPMs). SPMs can modulate leukocyte migration and function, alter cytokine/chemokine release, modify autophagy, among other immune-related activities. Here, we summarize the role of the lymphatics in resolution of inflammation and lymphatic impairment in chronic inflammatory diseases. Furthermore, we discuss the current literature describing the connection between SPMs and the lymphatics, and the possibility of targeting the lymphatics with innovative SPM therapy to promote resolution of inflammation and mitigate disease.
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| 9. |
- Lange, Stephan, et al.
(author)
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miR-486 is modulated by stretch and increases ventricular growth
- 2019
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In: Jci Insight. - : American Society for Clinical Investigation. - 2379-3708. ; 4:19
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Journal article (peer-reviewed)abstract
- Perturbations in biomechanical stimuli during cardiac development contribute to congenital cardiac defects such as hypoplastic left heart syndrome (HLHS). This study sought to identify stretch-responsive pathways involved in cardiac development. miRNA-Seq identified miR-486 as being increased in cardiomyocytes exposed to cyclic stretch in vitro. The right ventricles (RVs) of patients with HLHS experienced increased stretch and had a trend toward higher miR-486 levels. Sheep RVs dilated from excessive pulmonary blood flow had 60% more miR-486 compared with control RVs. The left ventricles of newborn mice treated with miR-486 mimic were 16.9%-24.6% larger and displayed a 2.48-fold increase in cardiomyocyte proliferation. miR-486 treatment decreased Fox01 and Smad signaling while increasing the protein levels of Stat1. Stat1 associated with Gata-4 and serum response factor (Srf), 2 key cardiac transcription factors with protein levels that increase in response to miR-486. This is the first report to our knowledge of a stretch-responsive miRNA that increases the growth of the ventricle in vivo.
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| 10. |
- Lange, Stefan, 1948, et al.
(author)
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Students at a crossroad: A cross-sectional survey gauging the impact of COVID-19 on medical and biomedical graduates in the United States and Sweden
- 2023
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In: Biochemistry and Molecular Biology Education. - 1470-8175. ; 51:5, s. 508-519
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Journal article (peer-reviewed)abstract
- Graduate programs in medicine and biomedical sciences have been severely impacted by the SARS-CoV-2/COVID-19 pandemic over the last 2 years. Following 2 years since beginning of the pandemic, data on student support, educational and academic performance as well as sentiment on changes to educational programs are starting to emerge. We performed and compared results of two cross-sectional surveys of Swedish and U.S.-based medical and biomedical graduate students on how the pandemic has affected their studies, research productivity and career trajectory. Students were also asked to assess support provided by the university and supervisors. The surveys also captured student demographics and a range of other factors, such as pressures brought on by caretaking and financial responsibilities. We analyzed answers from 264 and 106 students attending graduate programs in universities in Sweden and the United States, respectively. U.S.-based students faced more severe restrictions on their research program compared to students in Sweden, reporting more delays in productivity, scientific output and graduation, and increased worries about their career trajectory. Swedish students had more caretaking responsibilities, although these did not cause any delays in graduation. While support by universities and supervisors was comparable between the countries, financial worries and mental health concerns were particularly prominent in the U.S. cohort. Student performance and outlook was hugely dependent on the breadth of the restrictions and the available support. Besides the governmental and university-led approach to counter the pandemic, societal differences also played a role in how well students were handling effects of the pandemic.
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