| 1. |
- Park, Kyong-Su, et al.
(författare)
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Detoxified synthetic bacterial membrane vesicles as a vaccine platform against bacteria and SARS-CoV-2
- 2023
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Ingår i: Journal of Nanobiotechnology. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- The development of vaccines based on outer membrane vesicles (OMV) that naturally bud off from bacteria is an evolving field in infectious diseases. However, the inherent inflammatory nature of OMV limits their use as human vaccines. This study employed an engineered vesicle technology to develop synthetic bacterial vesicles (SyBV) that activate the immune system without the severe immunotoxicity of OMV. SyBV were generated from bacterial membranes through treatment with detergent and ionic stress. SyBV induced less inflammatory responses in macrophages and in mice compared to natural OMV. Immunization with SyBV or OMV induced comparable antigen-specific adaptive immunity. Specifically, immunization with Pseudomonas aeruginosa-derived SyBV protected mice against bacterial challenge, and this was accompanied by significant reduction in lung cell infiltration and inflammatory cytokines. Further, immunization with Escherichia coli-derived SyBV protected mice against E. coli sepsis, comparable to OMV-immunized group. The protective activity of SyBV was driven by the stimulation of B-cell and T-cell immunity. Also, SyBV were engineered to display the SARS-CoV-2 S1 protein on their surface, and these vesicles induced specific S1 protein antibody and T-cell responses. Collectively, these results demonstrate that SyBV may be a safe and efficient vaccine platform for the prevention of bacterial and viral infections
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| 2. |
- Park, Kyong-Su, et al.
(författare)
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Mesenchymal stromal cell-derived nanovesicles ameliorate bacterial outer membrane vesicle-induced sepsis via IL-10.
- 2019
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Ingår i: Stem cell research & therapy. - : Springer Science and Business Media LLC. - 1757-6512. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Sepsis remains a source of high mortality in hospitalized patients despite proper antibiotic approaches. Encouragingly, mesenchymal stromal cells (MSCs) and their produced extracellular vesicles (EVs) have been shown to elicit anti-inflammatory effects in multiple inflammatory conditions including sepsis. However, EVs are generally released from mammalian cells in relatively low amounts, and high-yield isolation of EVs is still challenging due to a complicated procedure. To get over these limitations, vesicles very similar to EVs can be produced by serial extrusions of cells, after which they are called nanovesicles (NVs). We hypothesized that MSC-derived NVs can attenuate the cytokine storm induced by bacterial outer membrane vesicles (OMVs) in mice, and we aimed to elucidate the mechanism involved.NVs were produced from MSCs by the breakdown of cells through serial extrusions and were subsequently floated in a density gradient. Morphology and the number of NVs were analyzed by transmission electron microscopy and nanoparticle tracking analysis. Mice were intraperitoneally injected with Escherichia coli-derived OMVs to establish sepsis, and then injected with 2×109 NVs. Innate inflammation was assessed in peritoneal fluid and blood through investigation of infiltration of cells and cytokine production. The biodistribution of NVs labeled with Cy7 dye was analyzed using near-infrared imaging.Electron microscopy showed that NVs have a nanometer-size spherical shape and harbor classical EV marker proteins. In mice, NVs inhibited eye exudates and hypothermia, signs of a systemic cytokine storm, induced by intraperitoneal injection of OMVs. Moreover, NVs significantly suppressed cytokine release into the systemic circulation, as well as neutrophil and monocyte infiltration in the peritoneum. The protective effect of NVs was significantly reduced by prior treatment with anti-interleukin (IL)-10 monoclonal antibody. In biodistribution study, NVs spread to the whole mouse body and localized in the lung, liver, and kidney at 6h.Taken together, these data indicate that MSC-derived NVs have beneficial effects in a mouse model of sepsis by upregulating the IL-10 production, suggesting that artificial NVs may be novel EV-mimetics clinically applicable to septic patients.
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| 3. |
- Park, Kyong-Su, et al.
(författare)
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Synthetic bacterial vesicles combined with tumour extracellular vesicles as cancer immunotherapy
- 2021
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Ingår i: Journal of Extracellular Vesicles. - : Wiley. - 2001-3078. ; 10:9
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Tidskriftsartikel (refereegranskat)abstract
- Bacterial outer membrane vesicles (OMV) have gained attention as a promising new cancer vaccine platform for efficiently provoking immune responses. However, OMV induce severe toxicity by activating the innate immune system. In this study, we applied a simple isolation approach to produce artificial OMV that we have named Synthetic Bacterial Vesicles (SyBV) that do not induce a severe toxic response. We also explored the potential of SyBV as an immunotherapy combined with tumour extracellular vesicles to induce anti-tumour immunity. Bacterial SyBV were produced with high yield by a protocol including lysozyme and high pH treatment, resulting in pure vesicles with very few cytosolic components and no RNA or DNA. These SyBV did not cause systemic pro-inflammatory cytokine responses in mice compared to naturally released OMV. However, SyBV and OMV were similarly effective in activation of mouse bone marrow-derived dendritic cells. Co-immunization with SyBV and melanoma extracellular vesicles elicited tumour regression in melanoma-bearing mice through Th-1 type T cell immunity and balanced antibody production. Also, the immunotherapeutic effect of SyBV was synergistically enhanced by anti-PD-1 inhibitor. Moreover, SyBV displayed significantly greater adjuvant activity than other classical adjuvants. Taken together, these results demonstrate a safe and efficient strategy for eliciting specific anti-tumour responses using immunotherapeutic bacterial SyBV.
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| 4. |
- Svennerholm, Kristina, 1981, et al.
(författare)
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Escherichia coli outer membrane vesicles can contribute to sepsis induced cardiac dysfunction.
- 2017
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Sepsis induced cardiac dysfunction (SIC) is a severe complication to sepsis which significantly worsens patient outcomes. It is known that bacteria have the capacity to release outer membrane vesicles (OMVs), which are nano-sized bilayered vesicles composed of lipids and proteins, that can induce a fatal inflammatory response. The aim of this study was to determine whether OMVs from a uropathogenic Escherichia coli strain can induce cardiac dysfunction, and to elucidate any mechanisms involved. OMVs induced irregular Ca2+ oscillations with a decreased frequency in cardiomyocytes through recordings of intracellular Ca2+ dynamics. Mice were intraperitoneally injected with bacteria-free OMVs, which resulted in increased concentration of pro-inflammatory cytokine levels in blood. Cytokines were increased in heart lysates, and OMVs could be detected in the heart after OMVs injection. Troponin T was significantly increased in blood, and echocardiography showed increased heart wall thickness as well as increased heart rate. This study shows that E. coli OMVs induce cardiac injury in vitro and in vivo, in the absence of bacteria, and may be a causative microbial signal in SIC. The role of OMVs in clinical disease warrant further studies, as bacterial OMVs in addition to live bacteria may be good therapeutic targets to control sepsis.
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| 5. |
- Einarsson, Freyr, et al.
(författare)
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Outcomes of catheter-directed interventions in high-risk pulmonary embolism-a retrospective analysis
- 2021
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 65:4, s. 499-506
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Tidskriftsartikel (refereegranskat)abstract
- Background First-line treatment of high-risk pulmonary embolism with persistent hypotension and/or signs of shock is intravenous thrombolysis. However, if thrombolysis is contraindicated due to risk of serious bleeding, or if it yields insufficient effect, surgical thrombectomy or catheter-directed intervention (CDI) plus anticoagulation is recommended. The aim of this study was to assess the outcomes of the CDI modality introduced in a tertiary referral centre in 2013. Methods Retrospective comparison between patients treated with CDI plus anticoagulation (n = 22) and patients treated with anticoagulation only (n = 23) as used before the CDI technique was available. The main outcomes of interest were 90-day survival and reduction of right to left ventricle diameter (RV/LV) ratio, using the Fischer's exact test and a mixed model, respectively, for statistical analysis. Results Ninety-day survival was 59% after CDI and 61% after anticoagulation only; P = .903. The rate of RV/LV ratio reduction was 0.4 units higher per 24 hours in the CDI group (median 2.1 pre-treatment), than in the anticoagulation only group (median 1.3 pre-treatment); P = .007. Conclusion In patients with high-risk pulmonary embolism, 90-day survival was similar after treatment with CDI plus anticoagulation compared to anticoagulation only. The mean reduction in RV/LV ratio was larger in the CDI group. Our results support the use of CDI in selected patients, respecting the limitations and potential side effects of each technical device used.
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| 6. |
- Osbeck Sandblom, H., et al.
(författare)
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Characterization of dysphagia and laryngeal findings in COVID-19 patients treated in the ICU-An observational clinical study
- 2021
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 16:6
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Tidskriftsartikel (refereegranskat)abstract
- Background Dysphagia appears to be common in patients with severe COVID-19. Information about the characteristics of dysphagia and laryngeal findings in COVID-19 patients treated in the intensive care unit (ICU) is still limited. Objectives The aim of this study was to evaluate oropharyngeal swallowing function and laryngeal appearance and function in patients with severe COVID-19. Method A series of 25 ICU patients with COVID-19 and signs of dysphagia were examined with fiberendoscopic evaluation of swallowing (FEES) during the latter stage of ICU care or after discharge from the ICU. Swallowing function and laryngeal findings were assessed with standard rating scales from video recordings. Results Pooling of secretions was found in 92% of patients. Eleven patients (44%) showed signs of silent aspiration to the trachea on at least one occasion. All patients showed residue after swallowing to some degree both in the vallecula and hypopharynx. Seventy-six percent of patients had impaired vocal cord movement. Erythema of the vocal folds was found in 60% of patients and edema in the arytenoid region in 60%. Conclusion Impairment of oropharyngeal swallowing function and abnormal laryngeal findings were common in this series of patients with severe COVID-19 treated in the ICU. To avoid complications related to dysphagia in this patient group, it seems to be of great importance to evaluate the swallowing function as a standard procedure, preferably at an early stage, before initiation of oral intake. Fiberendoscopic evaluation of swallowing is preferred due to the high incidence of pooling of secretion in the hypopharynx, silent aspiration, and residuals. Further studies of the impact on swallowing function in short- and long-term in patients with COVID-19 are warranted.
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| 7. |
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| 8. |
- Svennerholm, Kristina, 1981, et al.
(författare)
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DNA Content in Extracellular Vesicles Isolated from Porcine Coronary Venous Blood Directly after Myocardial Ischemic Preconditioning
- 2016
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 11:7
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Tidskriftsartikel (refereegranskat)abstract
- Background Extracellular vesicles (EV) are nano-sized membranous structures released from most cells. They have the capacity to carry bioactive molecules and gene expression signals between cells, thus mediating intercellular communication. It is believed that EV confer protection after ischemic preconditioning (IPC). We hypothesize that myocardial ischemic preconditioning will lead to rapid alteration of EV DNA content in EV collected from coronary venous effluent. In a porcine myocardial ischemic preconditioning model, EV were isolated from coronary venous blood before and after IPC by differential centrifugation steps culminating in preparative ultracentrifugation combined with density gradient ultracentrifugation. The EV preparation was validated, the DNA was extracted and further characterized by DNA sequencing followed by bioinformatics analysis. Porcine genomic DNA fragments representing each chromosome, including mitochondrial DNA sequences, were detected in EV isolated before and after IPC. There was no difference detected in the number of sequenced gene fragments (reads) or in the genomic coverage of the sequenced DNA fragments in EV isolated before and after IPC. Gene ontology analysis showed an enrichment of genes coding for ion channels, enzymes and proteins for basal metabolism and vesicle biogenesis and specific cardiac proteins. This study demonstrates that porcine EV isolated from coronary venous blood plasma contain fragments of DNA from the entire genome, including the mitochondria. In this model we did not find specific qualitative or quantitative changes of the DNA content in EV collected immediately after an in vivo myocardial IPC provocation. This does not rule out the possibility that EV DNA content changes in response to myocardial IPC which could occur in a later time frame.
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| 9. |
- Svennerholm, Kristina, 1981
(författare)
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Epigenetic influence on cardiovascular protective mechanisms in vivo: explorations of t-PA release and extracellular vesicle genetic content
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- ABSTRACT Background: Ischemic heart disease is one of the leading causes of death globally. This thesis explores endogenous mechanisms protecting against myocardial ischemia in context of epigenetics (changes in gene activity not caused by changes in DNA sequences). Epigenetic regulation of vascular thromboprotective mechanism was assessed, as well as the capacity of extracellular vesicle (EV) involvement in mediating epigenetic changes related to cardioprotection in ischemic preconditioning (IPC). Aims: The aim of Papers I and II was to evaluate if histone deacetylase inhibition, by valproic acid (VPA) treatment, increases stimulated tissue plasminogen activator (t-PA) release capacity and affects plasminogen activator inhibitor-1 (PAI-1) levels in vivo, in healthy large animals and in an atherosclerotic cohort. The aim of Papers III and IV was to assess if coronary venous EV genetic content is affected by myocardial IPC in vivo. Methods: In a porcine myocardial ischemia model transcoronary t-PA release was measured and compared between VPA treated (n=12) and untreated animals (n=10). In the clinical cross-over study (n=16), the perfused forearm model was used to measure single and repeated t-PA release capacity by isoprenaline provocation with and without VPA. PAI-1 was also measured. In a porcine model, EV were collected from coronary venous blood before and after myocardial IPC. The EV were isolated by differential ultracentrifugation and the preparation was evaluated by western blot, electron microscopy and nanoparticle tracking analysis. Changes in EV genetic content after IPC were identified by microarray and DNA sequencing. Results: Animals treated with VPA demonstrated a significantly higher cumulative transcoronary t-PA release compared to controls. In the clinical study, VPA treatment resulted in increased cumulative t-PA release capacity during repeated isoprenaline stimulation, though there was no difference when comparing single stimulation sequences. Levels of PAI-1 were reduced after VPA treatment. Among 11678 mRNA sequences detected in EV, about 10% were up or down regulated after IPC. Among these, over half were increased, including several with association to cardioprotection and IPC. DNA fragments, representing all porcine chromosomes, were identified in EV. The DNA content in EV changed after myocardial IPC. Conclusions: Intervention of HDACi, by VPA treatment, may improve actions of the fibrinolytic system by enhancing t-PA release capacity and reducing PAI-1 levels in vivo. In a future perspective, this may have clinical relevance as novel means of preventive strategies for ischemic heart disease. Myocardial IPC influences the composition of EV genetic content, including increases in gene transcripts associated to cardioprotecion. This may reflect a biological relevance of EV in delivering cardioprotective signals in IPC, although further studies are necessary to confirm such connection.
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| 10. |
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| 11. |
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| 12. |
- Svennerholm, Kristina, 1981, et al.
(författare)
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Myocardial ischemic preconditioning in a porcine model leads to rapid changes in cardiac extracellular vesicle messenger RNA content
- 2015
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Ingår i: International Journal of Cardiology Heart and Vasculature. - : Elsevier. - 2352-9067. ; 8, s. 62-67
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Tidskriftsartikel (refereegranskat)abstract
- Background: Extracellular vesicles (EVs) are thought to exert protective effects after ischemic and remote ischemic preconditioning. It is not well understood which EV content factors are most relevant for protective effects. We hypothesize that ischemic preconditioning leads to qualitative changes in EV mRNA content and quantitative changes in EV size and number.Methods: Using an in vivo porcine ischemic preconditioning model, EVs were collected from coronary venous blood, and isolated by differential ultracentrifugations. The presence and purity of EV were verified by electron microscopy and Western blot, and EV number was assessed by nanoparticle tracking analysis. The mRNA EV was identified by microarray.Results: Gene ontology analysis showed enrichment of EV mRNA coding for proteins associated with regulation of transcription, translation, extracellular matrix, morphogenic development and feeding behavior. There were 11,678 different mRNA transcripts detected in EV, where a total of 1103 was significantly increased or decreased after preconditioning, of which 638 mRNA sequences were up-regulated and/or emerged due to preconditioning. Several of them have known association with ischemic preconditioning. There was no significant difference in EV quantity or size before and after preconditioning.Conclusions: These findings demonstrate in an in vivo model that myocardial ischemic preconditioning influences the composition of mRNA in EV, including gene transcripts for proteins associated with the protective effect of ischemic preconditioning. The finding that preconditioned parental cells release EV containing mRNA that is qualitatively different from those released by non-preconditioned cells shows the importance of the external milieu on parental cell EV production.
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| 13. |
- Wisén, Ellinor, 1978, et al.
(författare)
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Argipressin for prevention of blood loss during liver resection: a study protocol for a randomised, placebo-controlled, double-blinded trial (ARG-01)
- 2023
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Ingår i: BMJ open. - 2044-6055. ; 13:8
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Tidskriftsartikel (refereegranskat)abstract
- Liver resection carries a high risk for extensive bleeding and need for blood transfusions, which is associated with significant negative impact on outcome. In malignant disease, the most common indication for surgery, it also includes increased risk for recurrence of cancer. Argipressin decreases liver and portal blood flow and may have the potential to reduce bleeding during liver surgery, although this has not been explored.ARG-01 is a prospective, randomised, placebo-controlled, double-blinded study on 248 patients undergoing liver resection at Sahlgrenska University Hospital, Sweden. Patients will be randomised to one of two parallel groups, infusion of argipressin or normal saline administered peroperatively. The primary endpoint is peroperative blood loss. Secondary outcomes include need for blood transfusion, perioperative variables, length of hospital stay, the inflammatory response, organ damage markers and complications at 30 days.The study is enrolling patients since March 2022. The trial is approved by the Swedish Ethical Review Authority (Dnr 2021-03557) and the Swedish Medical Product Agency (Dnr 5.1-2021-90115). Results will be announced at scientific meetings and in international peer-reviewed journals.ClinicalTrials.gov, NCT05293041 and EudraCT, 2021-001806-32.
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| 14. |
- Wisén, Ellinor, 1978, et al.
(författare)
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Myocardial, renal and intestinal injury in liver resection surgery-A prospective observational pilot study
- 2021
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 65:7, s. 886-894
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Tidskriftsartikel (refereegranskat)abstract
- Background Post-operative organ complications in liver resection surgery are not uncommon. This prospective observational pilot study was performed to evaluate the incidence, degree and timing of myocardial, renal and intestinal injury in patients undergoing liver resection surgery using the low central venous pressure (LCVP) technique and the Pringle manoeuvre. Methods Blood samples were obtained before, during and after elective liver resection until post-operative day (POD) 5. High-sensitive troponin T (hs-TnT), serum creatinine, urea, intestinal fatty acid binding protein (I-FABP), D-lactate, arterial lactate, portal lactate, amylase, as well as urine N-acetyl-ss-D-glucosaminidase (NAG) were analysed. Systemic haemodynamics were measured intraoperatively. Results Eighteen patients fulfilled the protocol. The Pringle manoeuvre was used in all but 1 patient. hs-TnT increased significantly over time (P < .001) and 5 patients (28%) developed myocardial injury. Five patients had a pre-operative elevation of hs-TnT, four of those developed myocardial injury. Serum creatinine increased significantly over time (P = .015). Acute kidney injury (AKI) occurred in 5 patients (28%), while NAG, as a marker of tubular injury, was not affected. I-FABP increased over time (P < .001) with a maximal 75% increase at 3 hours after resection. D-lactate was below detection level at all measuring points. Conclusions In patients undergoing liver resection surgery, using LCVP technique and Pringle manoeuvre, myocardial injury was seen in approximately 30% of the patients post-operatively and almost 30% developed transient AKI in the early post-operative period with no tubular injury. Furthermore, a transient increase of the enterocyte damage marker I-FABP was demonstrated with no signs of gut barrier dysfunction.
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| 15. |
- Wisén, Ellinor, 1978, et al.
(författare)
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Vasopressin and nitroglycerin decrease portal and hepatic venous pressure and hepato-splanchnic blood flow
- 2018
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; 62:7, s. 953-961
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundVarious methods are used to reduce venous blood pressure in the hepato-splanchnic circulation, and hence minimise blood loss during liver surgery. Previous studies show that combination of vasopressin and nitroglycerin reduces portal pressure and flow in patients with portal hypertension, and in this study we investigated this combination in patients with normal portal pressure. MethodIn all, 13 patients were studied. Measurements were made twice to confirm baseline (C1 and BL), during vasopressin infusion 4.8 U/h (V), and during vasopressin infusion combined with nitroglycerin infusion (V + N). Portal venous pressure (PVP), hepatic venous pressure (HVP), central haemodynamics and arterial and venous blood gases were obtained at each measuring point, and portal (splanchnic) and hepato-splanchnic blood flow changes were calculated. ResultsVasopressin alone did not affect PVP, whereas HVP increased slightly. In combination with nitroglycerin, PVP decreased from 10.1 1.6 to 8.9 +/- 1.3 mmHg (P < 0.0001), and HVP decreased from 7.9 +/- 1.9 to 6.2 +/- 1.3 mmHg (P = 0.001). Vasopressin reduced portal blood flow by 47 +/- 19% and hepatic venous flow by 11 +/- 18%, respectively. Addition of nitroglycerin further reduced portal- and hepatic flow by 55 +/- 13% and 30 +/- 13%, respectively. Vasopressin alone had minor effects on central haemodynamics, whereas addition of nitroglycerin reduced cardiac index (3.2 +/- 0.7 to 2.7 +/- 0.5; P < 0.0001). The arterial-portal vein lactate gradient was unaffected. ConclusionThe combination of vasopressin and nitroglycerin decreases portal pressure and hepato-splanchnic blood flow, and could be a potential treatment to reduce bleeding in liver resection surgery.
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